JP4633769B2 - Sludge dewatering equipment - Google Patents

Description

  The present invention relates to a sludge dewatering device for dewatering a sludge to produce a dehydrated sludge having a low water content, in which a flocculant is injected into the sludge and dewatering with a sludge dewatering machine.

  Conventionally, various devices are used for sludge dewatering equipment that produces dehydrated sludge with low moisture content by separating water from treated sludge with high moisture content, such as primary sedimentation sludge, surplus sludge, digested sludge, etc. Has been.

  Patent Document 1 discloses an example of a sludge dewatering device using a centrifugal dehydrator. The sludge dewatering device disclosed in Patent Document 1 includes a sludge supplying device, a centrifugal dewatering device (sludge dewatering device), and a chemical supplying device. The sludge supply device temporarily stores raw sludge (treated sludge) in a sludge tank and pumps it to a centrifugal dehydrator using a sludge supply pump and piping (sludge supply pipe). In addition, the chemical supply device mixes solid flocculant and water for dissolution with a mixer, puts it in the flocculant tank, and stirs it with the stirrer provided in the flocculant tank to dissolve the flocculant in water. Thus, a flocculant solution is generated and stored, and is pumped as much as necessary to the centrifugal dehydrator with a chemical supply pump and piping. The centrifugal dehydrator introduces raw sludge, which is sent from the sludge supply device and mixed with the flocculant solution sent from the chemical supply device to form sludge flocks (sludge agglomerates), into the outer bowl, and further As the barrel bowl rotates, centrifugal force acts on the raw sludge in the outer barrel bowl, and the sludge floc aggregate sludge cake (dehydrated sludge) and clarified water (separate) are centrifuged. The sludge cake having a reduced water content by centrifugation is transported to the discharge port and discharged to the outside by a screw conveyor that rotates with a differential speed relative to the outer shell bowl.

  In addition to the centrifugal dehydrator, a belt press dehydrator, a screw press dehydrator and the like are widely known as the sludge dehydrator. Moreover, although the water content reduction performance of the to-be-treated sludge is lower than that of a centrifugal separator or the like, a screen-type sludge concentrator, a centrifugal sludge concentrator, or the like is also used as a kind of sludge dehydrator depending on its use.

  It is possible to reduce the moisture content of the treated sludge simply by dehydrating with a sludge dehydrator without injecting the flocculant solution into the treated sludge. In this case, however, the water content of the dewatered sludge does not drop so much because the sludge suspended particles are small, and the fine sludge suspended particles are easily mixed with the separated water, and the quality of the separated water is poor. For this reason, usually, in a sludge dewatering apparatus, a flocculant solution that promotes the formation of sludge flocs is often injected into the treated sludge and dewatered by a sludge dewatering machine. As equipment for supplying the flocculant solution, the solid flocculant and the dissolved water are directly fed directly to the flocculant storage tank without providing a mixer, in addition to the structure shown in Patent Document 1 above. In addition, there is a configuration in which stirring is performed with a stirrer.

  The flocculant applied in the sludge dewatering apparatus includes inorganic flocculants and polymer flocculants. Normally, suspended substance particles in the treated sludge repel each other because the surface is negatively charged, making it difficult to form sludge flocs. The inorganic flocculant neutralizes the negative charge on the particle surface of the sludge suspended material, facilitates the intermolecular force between the sludge suspended material particles, and aggregates the sludge particles to form sludge flocs. Is. Examples of inorganic flocculants include polyaluminum chloride and polyferric sulfate. When dissolved in water, Al and Fe become polyvalent cations with a large positive charge, and these polyvalent cations become the sludge particle surface. The negative charge is neutralized.

  On the other hand, when the polymer flocculant is dissolved in water, it is in a polymer chain (string-like) state and exists in water. Polymer flocculants are broadly classified into cationic (cation), anion (anion), nonion (non-ion), and amphoteric (polymers having both a cation group and an anion group). The In the case of sludge suspended particles, since they are normally negatively charged, cationic or amphoteric ones are applied. In both cases of the cationic polymer flocculant and the amphoteric polymer flocculant, the cationic group portion neutralizes the negative charge of the sludge suspended material particles, and the intermolecular force between the sludge suspended material particles. In addition, the polymer chains are entangled with each other and crosslinked (in the case of amphoteric systems, in addition to this, electrostatic force generated between the cation part and the anion part remaining in the neutralization stage is also added). Sludge flocs are agglomerated and formed. Compared to inorganic flocculants, in addition to the intermolecular forces between sludge suspended particles, it also has effects such as cross-linking of polymer chains, which can promote the aggregation and formation of larger sludge flocs. For this reason, in recent years, a polymer flocculant is often added in the dewatering treatment of the treated sludge.

  Some flocculants are in liquid form, but are usually commercialized in a granular or powdered solid state for the purpose of extending the storage period and for convenience such as transportation. And as shown with the chemical | medical agent supply apparatus etc. of the said patent document 1, it uses, after stirring the mixture of a solid flocculant and dissolution water with a stirrer in the flocculant storage tank, and dissolving a solid flocculant. It is like that. Since the inorganic flocculant has a relatively simple molecular structure, it can be dissolved in dissolved water in a relatively short time.

  On the other hand, the polymer flocculant is solidified in the form of particles or powders in a state where the polymer chains are entangled, and the case of dissolving the powder or granular inorganic flocculants in water is the process of dissolution Is slightly different. In the case of a polymer flocculant, water first penetrates and swells on the surface of the grain, and the polymer chains on the grain surface gradually unwind and spread, and water penetrates and penetrates through the widened gap. Since the layers swell and the polymer chains on the surface gradually unwind (separate) and dissolve slowly, it takes a considerable time to dissolve all (usually 1 hour or more). For this reason, a flocculant solution that has been dissolved is secured in one tank and injected into the sludge to be treated, and the flocculant is dissolved in the other tanks so that the flocculant can be dissolved. It was necessary to prepare two or more flocculant storage tanks for dissolving and storing the liquid. Since the flocculant storage tank has a large capacity and a plurality of the tanks are installed, a large installation space is required, which is a problem.

  In addition, when the polymer flocculant is dissolved in the above-mentioned disperser of the flocculant storage tank and the stirrer, the powdered or granular (hereinafter referred to as these states) in the dissolved water in the flocculant storage tank. When the polymer flocculant of generically called granular etc.) is added at once, a certain number of particles gather to form a lump before melting, so-called spatter. Once in this state, as described above, the dissolution process of the polymer flocculant gradually dissolves in the order of water penetration, swelling, and polymer chain separation from the outer periphery of the grain. If it becomes a lump, it will take much time for water to penetrate to the center of the lump, or water will not completely penetrate to the center of the lump, and the polymer flocculant will not completely dissolve There was a problem.

  In recent years, a mixing device (flocculating agent dissolver) shown in Patent Document 2 has been developed that can solve the problem of dissolving such a solid polymer flocculant in water. The configuration is as follows. A cylindrical filtering member (cylindrical screen) is provided in the cylindrical body (cylindrical container), and two flanges whose outer peripheral surfaces are in contact with the inner surface of the cylindrical body are provided at both ends of the cylindrical filtering member, A gap is formed between the two flanges, the outer peripheral surface of the cylindrical filtration member, and the inner peripheral surface of the cylindrical body. The cylinder other than the gap is provided with a supply port, and the cylinder in the gap is provided with a discharge port. A shaft to which a driving force is transmitted is rotatably inserted at the center of the cylindrical filtration member, and two flange portions (holding members) that rotate together with the shaft are attached. A concave portion is formed on the outer peripheral surface of the flange portion, and the rotation shaft of the roller (pressing member) is urged by the spring in a direction in which the roller is pressed against the inner peripheral surface of the cylindrical filtration member.

  In the mixing apparatus shown in Patent Document 2 having the above-described configuration, a processing liquid containing a spliced powder processed by a dissolving machine using a combination of a small-capacity flocculant mixing tank and a stirring device (stirrer) is mixed. The processing liquid flows in from the supply port, and the processing liquid in which the spatter is dissolved by the mixing apparatus flows out of the cylinder. Specifically, in the treatment liquid containing the splint in the cylinder, a solution in which a coagulant other than the spatter is dissolved passes from the inner peripheral surface of the cylindrical filter member to the outer peripheral surface and flows out into the gap. When the driving machine or the like is operated and the driving force is transmitted to the shaft, the roller moves along the inner peripheral surface of the cylindrical filtration member by the shaft and the flange portion, and the roller itself is also centered on the rotation axis. Rotate. At this time, the spatter moves along the inner peripheral surface of the cylindrical filtration member by the rotation of the shaft and is crushed by the roller. As a result, shear force is applied to the swollen swollen portion to entangle the polymer chains, and the swollen polymer chains are separated from the spatter and pass to the outer peripheral surface of the tubular filter member. The unswelled portion of the powder can come into contact with dissolved water and swell. Then, the new swollen portion is crushed by a roller, and by repeating the process in which the polymer chains in that portion are separated from the spliced powder, the spliced powder is dissolved. As described above, the mixing device shown in Patent Document 2 solves the problem that spatter remains in the treated water in the dissolver by the combination of a conventional flocculant storage tank and a stirrer. The effect of was able to be obtained.

  Moreover, the mixing apparatus of patent document 2 is not restricted only to the use which melt-processes the splint in a flocculant solution. Occurrence of spatter in the flocculant solution can be suppressed to an extent that does not cause a problem if small amounts of flocculant such as particles are put into a small capacity flocculant storage tank. However, this method has a problem that the storage amount of the flocculant solution that can be generated is small for a long time. In order to solve this problem, in a small-capacity flocculant storage tank, the flocculant and water are stirred and mixed for only a short time, and the undissolved particles remain in the flocculant solution. In some cases, the undissolved particles in the flocculant solution are dissolved by the mixing device. By using this configuration, it was possible to significantly shorten the time until a flocculant solution sufficiently dissolved in water was produced from a flocculant such as a granule, and an appropriate effect could be obtained.

JP 2006-192403 A Japanese Patent No. 318497

  In the mixing apparatus described in Patent Document 2, the configuration is such that the spatter and undissolved particles (hereinafter collectively referred to as undissolved particles) on the inner peripheral surface of the cylindrical filtration member are crushed by a roller biased by a spring. This makes it possible to dissolve undissolved grains in a short time, and to prevent excessive shearing force from being applied to the undissolved grains by an appropriate urging force by a spring, thereby polymer agglomeration. The breakage of the polymer chain of the agent can be prevented as much as possible. However, even if the undissolved particles can be crushed by an appropriate shearing force, if the rotation speed of the roller is not appropriate, a phenomenon that the polymer chain is broken occurs.

  The swollen part of the undissolved particles is slightly entangled between the polymer chains, but is difficult to separate unless external force is applied. The unswollen part of the undissolved particles is entangled between the polymer chains. The state is almost the same as before the solution was added to the dissolved water, and if the polymer chain is forcibly separated, the polymer chain is broken. As described above, the undissolved particles are crushed by the roller, so that the polymer chains are separated from the swelling portion outside the undissolved particles. Then, when water enters the unswelled part, which is the inner layer (second layer) that appears on the surface after separation, the water swells to become a new swollen part, and the polymer chain is crushed by the roller and separated. It is a process. However, if the rotational speed of the roller is higher than the appropriate value, water enters the unswelled part of the second layer to form a new swelled part, and before the entanglement of polymer chains is loosened, the next roller Even if the shearing force applied to the swollen portion is an appropriate value, an excessive shearing force is applied to the unswelled portion of the second layer. This causes a so-called over-stirring state that breaks the molecular chain.

  If the polymer chain is broken, the cross-linking action of the polymer chains entangled in the sludge to be treated and agglomerating particles of the sludge suspended material decreases, and the aggregation performance of the polymer flocculant also decreases. (The tendency to depend mainly on the intermolecular force between particles of sludge suspended matter becomes stronger.) For this reason, undissolved particles could be dissolved and the aggregation performance of the flocculant solution could be improved, but the agglomeration performance was not improved dramatically. In order to obtain a predetermined dewatering efficiency with the sludge dewatering machine, it is necessary to increase the amount of the polymer flocculant injected into the sludge to be treated.

  On the other hand, when the rotation speed of the roller is lower than the appropriate value, water is newly swelled in the unswelled part of the second layer after the polymer chain is separated from the swelled part of the undissolved particles by being crushed by the roller. It is possible to secure enough time until However, in order to dissolve all the undissolved particles, the unswelled part of the next third layer does not swell unless the polymer chain is separated by crushing with a roller when the unswelled part is sufficiently swollen. That is, if the rotational speed of the roller is lower than the appropriate value, it takes time to dissolve all undissolved grains.

  In a conventional dissolver, the flocculant solution is stored in a large-capacity (for example, necessary amount per day) tank for storing the flocculant solution over a long period of time, and the flocculant solution is dissolved and stored when necessary. Is injected into the treated sludge with a pump or the like. Therefore, the flocculant solution in the tank for storing the flocculant solution can maintain the dissolution concentration of a predetermined value after the dissolution process of the flocculant is completed.

  On the other hand, in the configuration using the small capacity flocculant mixing tank and the mixing device provided with the stirring device shown in Patent Document 2, the flocculant solution is generated and injected into the treated sludge when necessary. It has become a usage pattern. The treatment liquid containing undissolved particles in the flocculant solution storage tank is pumped to the mixing device by the tube pump. During the dissolution treatment, the tube pump quantitatively transfers the flocculant solution to the mixing device. Since it continues to be transferred, the time (passage time) from when the flocculant solution flows into the mixing apparatus until it flows out as the dissolved flocculant solution is generally constant. At this time, if the number of rotations of the roller of the mixing device is lower than the appropriate value and it takes time to dissolve all the undissolved particles, the undissolved particles in the flocculant solution that has flowed The flocculant solution having a concentration lower than the set value flows out of the mixing apparatus and is injected into the treated sludge. With a flocculant solution having a low dissolution concentration, it is difficult to obtain the maximum effect of the aggregation.

  Conventionally, in order for the flocculant solution to flow out from the mixing device at a predetermined concentration, the optimum number of rotations of the roller is manually adjusted so that the undissolved particles flowing into the mixing device together with the flocculant mixture are dissolved. And increasing the supply amount of the flocculant solution to the treated sludge. In the past, when the operation of the flocculant dissolver was manually adjusted, look at the indicators (measured values with a viscometer, etc.) that measure the degree of dissolution of the flocculant solution (the remaining state of undissolved particles in the liquid, etc.) It is not adjusted, but the workers experienced by seeing the dewatering performance (water content of dewatered sludge, water quality of the separated liquid, etc.) when the treated sludge injected with the flocculant solution was dewatered with a sludge dewatering machine. Therefore, the flocculant solution is not necessarily the optimal dissolution condition. Even if it is the optimum flocculant solution in the properties of the treated sludge at that time, if the properties of the treated sludge change, sufficient coagulation performance may not be demonstrated during the dewatering treatment in the sludge dewatering machine, It was. Even when changing the injection amount of the flocculant solution into the treated sludge, it was necessary to manually readjust the operation of the flocculant dissolver.

  If the coagulant solution dissolved by the coagulant dissolver is not sufficiently dissolved and the coagulant performance cannot be fully exhibited, and the worker cannot immediately readjust the coagulant dissolver, the coagulant This can be dealt with by increasing the supply amount of the solution. In this case, however, the consumption of the flocculant has increased and the running cost has increased.

  In the case of producing a flocculant solution by dissolving a granular inorganic flocculant with dissolved water, the method of adding the inorganic flocculant and dissolved water in a tank equipped with a conventional stirrer and stirring the polymer Although it is easier to dissolve than the flocculant, it takes time to sufficiently dissolve it, so it is necessary to prepare a plurality of tanks. For this reason, even in the case of an inorganic flocculant, the mixing apparatus having the configuration of Patent Document 2 may be used. However, since the inorganic flocculant dissolves in a shorter time than the polymer flocculant, a manual roller is used. In the present situation, the number of rotations has been set to a value higher than the amount that can be sufficiently melted. This has caused a problem that power consumption and wear of parts are increased more than necessary, resulting in increased running costs.

  Even when a concentrated liquid (emulsion state) polymer flocculant is dissolved in dissolved water to form a flocculant solution, the polymer chains are intertwined in the concentrated state and are equipped with a conventional stirrer. In the method in which the polymer flocculant and dissolved water are added to the tank and stirred, it is not easy to uniformly distribute the polymer chains in the liquid in a short time. For this reason, in the case of a concentrated liquid polymer flocculant, a mixing device having the configuration of Patent Document 2 has been used, but since it dissolves in a shorter time than the case of a granular polymer flocculant, the rotation speed is low. However, it was difficult to manually adjust the optimum rotation speed, and it was often over-stirred.

  The present invention has been made to solve the above-described problems, and is a sludge dewatering device that performs a dewatering process in which a sludge to be treated into which a flocculant solution has been injected is separated into a separation liquid and a dewatered sludge by a sludge dewatering machine. Even when applying the flocculant solution to be injected into a powder or granular solid or concentrated liquid flocculant dissolved in dissolved water, the flocculant has high coagulation performance in an optimal dissolution state. An object of the present invention is to provide a sludge dewatering apparatus that can inject a solution into a treated sludge and has high dewatering performance.

In order to solve the above problems, the sludge dewatering apparatus of the present invention includes a sludge dewatering machine that separates the treated sludge into a separation liquid and a dewatered sludge, a sludge supply pipe that supplies the treated sludge to the sludge dewatering machine, and agglomeration. A flocculant solution tank for producing a flocculant solution by stirring and mixing the agent and dissolved water , a cylindrical container, a cylindrical screen for filtering the flocculant solution disposed in the cylindrical container, and an inner surface of the cylindrical screen One or more pressing members that press and dissolve the adhering coagulant, a holding member that holds the pressing member, and the pressing member is moved along the inner surface of the cylindrical screen via the holding member. Provided with a drive unit, the flocculant solution is introduced and screen-filtered, and the flocculant dissolver that dissolves the flocculant in the flocculant solution and the viscosity of the flocculant solution flowing out of the flocculant dissolver are measured. A viscometer; Depending on the measured value of the viscometer, it is made of a controller for controlling the rotation of the drive machine to increase by starting at a low speed.

According to the sludge dewatering apparatus according to the present invention, when the flocculant in granular or concentrated liquid form is dissolved in the dissolved water to produce the flocculant solution, the flocculant and the dissolved water are stirred and mixed in the flocculant solution tank. A flocculant solution is generated, and the flocculant solution is taken into a flocculant dissolver, screen filtered, and further, undissolved particles are dissolved. The viscosity of the flocculant solution flowing out of the flocculant dissolver is measured by a viscometer. Based on the results measured in step (b), the controller controls the operation of the flocculant dissolver, thereby providing the following effects.
(1) The flocculant solution has a characteristic that the agglomeration performance varies depending on the degree of dissolution in the dissolved water, and the correlation between the dissolution condition and the agglomeration performance varies depending on the type of the aggregating agent to be used. Further, the degree of dissolution of the flocculant solution has a correlation with the viscosity. That is, there is a correlation between the viscosity of the flocculant solution and the aggregation performance. From this correlation, the viscosity at which the flocculant solution exhibits the optimum flocculation performance is specified in advance as the optimum value, stored in the controller, and the flocculent dissolver is operated according to the measured value of the viscometer. By controlling, it becomes possible to always supply the flocculant solution having the optimum flocculation performance to the sludge to be treated, and the dewatering performance is greatly improved.
(2) Since the viscosity is measured as an indicator of the degree of dissolution of the coagulant solution and the operation of the coagulant dissolver is adjusted by the controller according to the measured value, the type of coagulant supplied to the treated sludge Even when a change is made, a flocculant solution having the optimum flocculant performance can be immediately generated and supplied, and it has excellent responsiveness compared to conventional flocculant dissolvers and has the effect of constantly maintaining high dewatering performance.
(3) Even when the dissolution condition of the flocculant in the flocculant solution stirred and mixed in the flocculant solution tank changes due to fluctuations in the quality of the dissolved water and the water temperature, the dissolution treatment is performed by the flocculant dissolver. The measured flocculant solution is measured with a viscometer, and the controller controls the operation of the flocculant dissolver, so that the flocculant solution dissolved by the flocculant dissolver becomes over-stirred or under-stirred. There is an effect that the coagulation performance is prevented from being lowered, and the coagulant solution having the optimum dissolution condition and the optimum coagulation performance can be constantly generated and supplied to the treated sludge.
(4) Even when the supply amount of the flocculant solution to the treated sludge is increased or decreased, the controller adjusts the operation of the flocculant dissolver according to the measured value of the viscometer of the flocculant solution. Even if the flow rate of the flocculant solution into the dissolver changes, there is an effect that the flocculant solution having the optimum flocculant performance can be supplied.
(5) When manually adjusting a conventional flocculant dissolver, it is difficult for even a skilled worker to adjust so as to obtain an optimal dissolution condition, and the rotational speed is slightly lower than the optimal value. If adjusted, there is a concern about insufficient dissolution of the flocculant, and therefore, the number of rotations is usually adjusted to be slightly higher than the optimum value, and it seems to be over-stirred. Moreover, even if it is the flocculant solution produced | generated by the state of an over-stirring state and the flocculant performance fell a little, in order to exhibit high flocculant performance, more flocculant solution is supplied to to-be-processed sludge. In the sludge dewatering machine of this invention, the flocculant dissolver can be prevented from being over-stirred, so there is no need to supply more than a predetermined amount of the flocculant solution, and the effect of reducing the running cost can be achieved. is there.
(6) Since the operation of the coagulant dissolver can be maintained in an optimal state by the viscometer and the controller, it is optimal to adjust the operation of the coagulant dissolver manually and to ensure safety. Compared with the case where the adjustment has been made more excessively than the state, the power consumption can be reduced and the wear of the parts can also be reduced.

  According to the sludge dewatering apparatus according to the second aspect of the present invention, the flocculant solution generated by stirring and mixing the flocculant and the dissolved water in the flocculant solution tank is introduced into the cylindrical container of the flocculant dissolver. The flocculant solution with the undissolved particles remaining is covered by the filtration treatment with the cylindrical screen, and the undissolved particles of the flocculant adhering to the inner surface of the cylindrical screen are pressed with the pressing member. It is possible to prevent being supplied to the treated sludge and to surely dissolve undissolved particles.

  According to the sludge dewatering apparatus according to the third aspect of the present invention, the controller controls the rotation of the driving unit of the coagulant dissolving machine according to the measured value of the viscosity of the coagulant solution measured by the viscometer. By doing so, it is possible to adjust the speed at which the driving machine moves along the inner surface of the cylindrical screen of the pressing member to which the moving force is applied via the holding member. As a result, the pressing member can be controlled to an optimum moving speed, so that it is possible to prevent the flocculant solution from being insufficiently dissolved or over-stirred, and to achieve an optimum dissolution state that can exhibit high aggregation performance. In addition, even when the amount of the flocculant solution supplied to the sludge to be treated is increased or decreased, there is an effect that a dissolution process with excellent responsiveness can be performed.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a sludge dewatering apparatus according to Embodiment 1, FIG. 2 is a cross-sectional view of the flocculant dissolver as seen from the direction of line AA shown in FIG. 3, and FIG. It is sectional drawing seen from the BB line direction shown in FIG. The sludge dewatering device according to the first embodiment includes a sludge dewatering machine 1 that separates the treated sludge into a separation liquid and a dewatered sludge, a sludge supply pipe 2 that supplies the treated sludge to the sludge dewatering machine 1, a flocculant, A flocculant solution tank 3 for stirring and mixing dissolved water to form a flocculant solution; a flocculant dissolver 4 for introducing the flocculant solution and performing screen filtration and dissolving the flocculant in the flocculant solution; It mainly comprises a viscometer 5 that measures the viscosity of the flocculant solution that has flowed out of the flocculent dissolver 4 and a controller 6 that controls the operation of the flocculant dissolver 4 according to the measured value of the viscometer 5. Has been.

  In addition to the centrifugal dehydrator illustrated in FIG. 1, a belt press dehydrator, a screw press dehydrator, a rotary pressure dehydrator, or the like can be applied to the sludge dehydrator 1. Further, as a sludge dehydrator in a broad sense, a screen concentrator, a flotation concentrator, a centrifugal concentrator, or the like can be applied. The sludge supply pipe 2 is provided with a sludge supply pump 2A for pumping the treated sludge to the sludge dewatering machine 1.

  A flocculant supply machine 7 is disposed on the upper part of the flocculant solution tank 3. The flocculant supply machine 7 stores a flocculant such as particles, and has a hopper-like container 70 provided with a flocculant supply port 70a for supplying the flocculant into the flocculant solution tank 3 at the lower end, and a flocculant supply port 70a. It is comprised by the supply port switch 9 provided with the drive device 8 arrange | positioned. The supply port switch 9 may have any structure, such as a slide shutter structure, a flapper valve structure, a butterfly valve structure, a meshing gear structure, etc., as long as the flocculant supply port 70a can be opened and closed by the driving force of the drive unit 8. Also good. In addition to driving by an electric motor, solenoid driving, pneumatic driving, and the like can be applied to the driving machine 8. The flocculant supply port 70a is liable to infiltrate the moisture vaporized in the flocculant solution tank 3, and the particles of the flocculant may be hardened. Therefore, it is desirable to maintain a dry state by providing a dryer or the like. . In the flocculant solution tank 3, dissolved water is supplied from a dissolved water supply pipe 10 via a control valve 11. As the dissolved water, tap water, ground water, industrial water, filtered water, rainwater use water, reclaimed water, and the like can be applied.

  As the flocculant supplied from the flocculant supply machine 7 to the flocculant solution tank 3, particulate inorganic flocculants and polymer flocculants can be applied. Inorganic flocculants include polyaluminum chloride, polyiron sulfate, ferric chloride, aluminum sulfate, aluminum chloride and the like. The polymer flocculant includes amphoteric polymers such as methacrylic acid ester (eg, dimethylaminoethyl methacrylate) and acrylic acid ester (eg, dimethylaminoethyl acrylate), such as dimethyl acrylate. Examples include copolymers of aminoethyl and acrylic acid. Any agent can be applied as long as it is a granular agent having an action of promoting aggregation of suspended particles in the treated sludge.

  The flocculant solution tank 3 is provided with a stirrer 12 for stirring and mixing the flocculant supplied from the flocculant supplier 7 and the dissolved water supplied from the dissolved water supply pipe 10 to generate a flocculant solution. ing. The stirrer 12 includes a drive machine 12A such as an electric motor, and a stirring blade 12C that is connected to the rotation output shaft 12B of the drive machine 12A and is disposed near the inner bottom of the flocculant solution tank 3. . Further, in the flocculant solution tank 3, a water level meter 13 made of an electrode rod is disposed. Further, the flocculant solution tank 3 is provided with a water level gauge 13 for detecting the water level of the flocculant solution, and is connected to the controller 6 by electric wiring. When the liquid level in the flocculant solution tank 3 rises abnormally due to a failure of the control valve 11 or the pumping pump 15, the water level gauge 13 detects that, and an alarm is issued. It can be done.

  The flocculant solution produced in the flocculant solution tank 3 is a flocculant solution transfer pipe that connects the outlet provided at the bottom of the flocculant solution tank 3 and the flocculant solution inlet 41 c of the flocculant dissolver 4. 14 and the flocculant solution transfer pipe 14 are pumped into the flocculant dissolver 4 by a pump 15. The pumping pump 15 is applicable to any pump that can pump the coagulant solution, such as a centrifugal pump typified by a vortex pump and a positive displacement pump typified by a uniaxial screw pump. Since this coagulant solution may contain a considerable amount of undissolved particles, it is desirable to apply a positive displacement pump.

  The flocculant dissolver 4 includes a cylindrical tubular container 40, a cylindrical screen 45 that is disposed in the tubular container 40 and filters the flocculant solution, and a flocculant that adheres to the inner surface of the cylindrical screen 45. The pressing member 46 to be dissolved (four pieces in FIG. 2), holding members 47A and 47B for holding both ends of the pressing member 46, and the pressing member 46 of the cylindrical screen 45 through the holding members 47A and 47B. It has a structure including a drive unit 48 that moves along the inner surface.

  More specifically, the cylindrical container 40 has flange portions 40A and 40B at both ends, and flange lids 41A and 41B are bolts and nuts via seal members (not shown) on these flange portions 40A and 40B. It is fixed by 42A and 42B. The outflow side of the flocculant solution transfer pipe 14 is connected to the flocculant solution inlet 41C provided in one flange lid 41A. Further, a pair of annular left and right partition members 43A and 43B that also serve as a holding member for the cylindrical screen 45 are provided on the inner peripheral surface of the cylindrical container 40, and the cylindrical screen is provided on these partition members 43A and 43B. Both ends of 45 are supported. The inside of the cylindrical container 40 is divided into a primary chamber 44A and a secondary chamber 44B by partition members 43A and 43B and a cylindrical screen 45. The flocculant solution flowing into the primary chamber 44A from the flocculant solution inlet 41C by the pumping force of the pressure pump 15 is filtered through the cylindrical screen 45 and flows out to the secondary chamber 44B side. . At this time, the undissolved particles in the flocculant solution cannot pass through the cylindrical screen 45 and adhere to the screen surface on the primary chamber 44A side.

  The driver 48 is disposed outside the flange lid 41B opposite to the flange lid 41A having the flocculant solution inlet 41C, and the drive shaft 48A of the driver 48 extends coaxially with the central axis of the cylindrical screen 45. A tip end portion is rotatably supported by the flange lid 41A via a bearing 49 with low friction. The drive shaft 48A is provided with a pair of left and right holding members 47A and 47B that rotate coaxially and integrally with the drive shaft 48A, and a plurality of parallel holding members 47A and 47B parallel to the drive shaft 48A (see FIG. In FIG. 2, four pressing members 46 are pivotally supported. These pressing members 46 circulate along the inner peripheral surface of the cylindrical screen 45 by the rotation of the drive shaft 48 </ b> A, and undissolved particles adhering to the inner surface of the cylindrical screen 45 are between the inner surface of the cylindrical screen 45. Press to dissolve.

  The pressing member 46 includes a shaft portion 461 supported at both ends by the holding members 47A and 47B and a contact portion 462 that covers the outer peripheral surface of the shaft portion 461 and directly presses undissolved particles. The holding members 47A and 47B and a biasing member such as a spring are supported so as to be biased toward the cylindrical screen 45 side. Although the holding members 47A and 47B and the pressing member 46 are configured, the pressing member 46 may be configured to move in contact with the inner surface of the cylindrical screen 45. In this case, however, the pressing member 46 and the like are worn. There is a risk of getting ahead. A thin film is formed on the inner surface of the cylindrical screen 45 by depositing undissolved particles when the flocculant solution is screen-filtered by the cylindrical screen 45, so that the pressing member 46 is cylindrical enough to press the thin film. If it is configured to move to the screen 45 in a non-contact state, it is desirable that the problem of wear can be solved. The drive 48 incorporates a speed reducer 48B that decelerates the rotational speed of a power source such as an electric motor, and is transmitted to the drive shaft 48A via the speed reducer 48B. When the power source of the drive machine 48 is an electric motor, it is desirable to control the rotation speed with an inverter.

  On the secondary chamber 44B side of the cylindrical container 40, a flocculant solution outlet 40C is provided. One end of the flocculant solution supply pipe 16 is connected to the flocculant solution outlet 40C, and the other end is joined and connected to the sludge supply pipe 2. The flocculant solution in the secondary chamber 44B filtered by the cylindrical screen 45 and subjected to the dissolution treatment of the undissolved particles flows out from the flocculant solution outlet 40C by the pumping force of the pumping pump 15, and the flocculant solution supply pipe 16 After that, the sludge to be treated flows through the sludge supply pipe 2.

As described above, the flocculant solution supply pipe 16 that connects the flocculant solution outlet 40C of the cylindrical container 40 and the sludge supply pipe 2 has a flocculant solution after dissolution treatment that flows through the flocculant solution supply pipe 16. A viscometer 5 is provided for measuring the viscosity of the water and sending the measured value signal to the controller 6. The viscometer 5 includes a rotary type, a vibration type, a thin tube type, and a falling body type, any of which can be applied, and the outline structure of each type will be described below.
(1) The rotary viscometer 5 inserts a rotating cylindrical tube that is rotated by the power of the driving machine into the coagulant solution to be measured, measures the rotational torque, and calculates the viscosity from the correlation with the rotational torque. It has a structure to do.
(2) The vibration-type viscometer 5 has a structure in which a vibrator is inserted into the liquid to be measured, and the viscosity is calculated from the correlation with the amplitude and the amount of current required to maintain vibration.
(3) The narrow tube type viscometer 5 has a structure in which a flocculant solution to be measured is passed through a thin tube, the differential pressure before and after the measurement is measured, and the viscosity is calculated from the correlation with the differential pressure.
(4) The falling body type viscometer 5 is filled with a flocculant solution to be measured in a vertically placed circular tube, and a cylindrical body is dropped therein to measure the dropping time. The viscosity is calculated from the correlation.

  The controller 6 controls the dissolved water supply amount (control valve 11), the control of the coagulant supply amount (coagulant supply device 7), the control of the stirrer 12, the control of the pumping pump 15, and the viscometer 5 The operation of the flocculant dissolver 4, that is, the rotational speed of the driving device 48 is controlled to increase or decrease according to the measured viscosity value of the flocculant solution. Hereinafter, the rotational speed control of the driving machine 48 by the controller 6 will be described. The controller 6 also controls the supply flow rate of the coagulant solution from the coagulant solution tank 3 to the coagulant dissolver 4. In order to control the supply amount, it is necessary to use a configuration in which the pressure pump 15 is a pump capable of controlling the number of revolutions by inverter control or the like, or a configuration in which a flow rate control valve is provided on the suction side or the discharge side of the pressure feed pump 15. is there.

  For each type of flocculant supplied from the flocculant supply machine 7 to the flocculant solution tank 3, the correlation between the viscosity of the flocculant solution and the dissolution condition or the aggregation performance is examined in advance, and the optimum dissolution condition or aggregation performance is determined. Is determined as an optimum value in the flocculant, and the viscosity of the optimum value (hereinafter referred to as the optimum viscosity value) is stored in the controller 6. A measured value signal is transmitted from the viscometer 5 constantly or every predetermined time to the controller 6 storing the optimum viscosity value.

  For example, the following control can be applied to the operation control when the coagulant dissolving machine 4 performs the dissolution treatment as a simple method. First, the driving machine 48 is started at a low speed, and the pressing member 46 is moved on the inner surface of the cylindrical screen 45 at a low speed to start the dissolution process of undissolved particles. The rotational speed of the drive 48 is gradually increased until the measured viscosity value of the dissolved flocculant solution measured by the viscometer 5 and taken into the controller 6 by the measured value signal becomes the optimum viscosity value. . When the measured viscosity value reaches the optimum viscosity value, the rotational speed of the driving device 48 is maintained. Normally, if the properties of the sludge to be treated are not significantly changed, the supply amount of the flocculant solution is not changed so much, and this simple control alone is sufficient. In addition, when the properties of the sludge to be treated deteriorate and it becomes necessary to increase the supply amount of the flocculant solution to the sludge to be treated, the flow rate of the flocculant solution dissolved by the flocculant dissolver 4 increases. Since the amount of undissolved particles adhering to the inner surface of the cylindrical screen 45 also increases, naturally the optimum rotational speed of the driving machine 48 changes. In this case, it is advisable to readjust the control by restarting the controller 6 by the operation manager of the sludge dewatering apparatus so that the same control is performed again to obtain the optimum rotation speed of the drive unit 48.

  In normal cases, the supply amount of the flocculant solution to the treated sludge is increased or decreased by the operation manager of the sewage dewatering device in view of the status of the dewatered sludge discharged from the sludge dewatering machine and the status of the separated liquid. Since the determination is made, it is less necessary for the controller 6 to automatically perform control for readjusting the rotational speed of the driving device 48 in accordance with increase or decrease in the supply amount of the flocculant solution. However, when the controller 6 automatically controls the supply amount of the flocculant solution according to the properties of the sludge to be treated, the flocculant supply is performed so that the controller 6 can recognize the change in the supply amount. It is preferable to control the rotational speed of the driving machine 48 by installing a flow meter in the pipe 16 or the like and incorporating a circuit for recognizing the rotational speed of the pressure pump 15 into the controller 6. In particular, when the supply amount of the flocculant solution automatically varies, it is difficult to control the driving device 48 only with the actual measurement data of the current viscosity measurement value. The viscosity measurement value up to the previous time or several times before can be stored in the controller 6, and a control for controlling the rotational speed of the driving device 48 by looking at the change in the viscosity of the flocculant solution is incorporated, It is desirable to incorporate advanced controls such as adaptive control, fuzzy control, and neural network control.

  Next, the operation of the sludge dewatering device in the first embodiment will be described. When the flocculant solution is supplied to the sludge to be treated, the driver 8 of the flocculant supply machine 7 is driven by the output signal from the controller 6 to open the supply port switch 9 and the dissolved water supply pipe 10. The control valve 11 is opened. At this time, granular coagulant (polymer coagulant) is supplied into the coagulant solution tank 3 from the coagulant supply port 70a of the coagulant supply unit 7, and dissolved water is supplied from the dissolved water supply pipe 10. However, the concentration of the flocculant solution after the dissolution treatment varies depending on the ratio of the flocculant and the amount of dissolved water supplied. This is a method for adjusting the concentration of the flocculant solution. The dissolved water supply pipe 10 is provided with a constant flow valve or a flow control valve so that the dissolved water supply flow rate to the flocculant solution tank 3 is adjusted to be constant. The concentration of the flocculant solution generated in the flocculant solution tank 3 can be freely changed by changing the supply amount of the flocculant to the flocculant solution tank 3 per predetermined time by controlling the supply port switch 9. Can be adjusted. However, the present invention is not limited to this method, and any method can be applied as long as the concentration of the flocculant solution can be adjusted. In the flocculant solution tank 3, the flocculant and the dissolved water are stirred and mixed by the stirrer 12 activated by the output signal from the controller 6, and the flocculant solution is flocculated. It is temporarily stored in the agent solution tank 3. The flocculant solution at this point is in a state where undissolved particles remain.

  The flocculant solution in the flocculant solution tank 3 is commensurate with the expected amount of flocculant solution supplied to the treated sludge when the pumping pump 15 of the flocculant solution transfer pipe 14 is activated by the output signal of the controller 6. It is transferred to the flocculant dissolver 4 at a predetermined flow rate only. As a result, the flocculant solution containing undissolved particles flows from the flocculant solution inlet 41C of the cylindrical container 40 of the flocculant dissolver 4 into the primary chamber 44A. The flocculant solution that has flowed into the primary chamber 44 </ b> A passes through the cylindrical screen 45, and undissolved particles in the flocculant solution adhere to the inner surface of the cylindrical screen 45 and are captured. At this time, the drive unit 48 of the four coagulant dissolving machines is activated by the output signal of the controller 6, and a plurality of pressing members are formed along the inner peripheral surface of the cylindrical screen 45 by the rotation of the drive shaft 48A. 46 goes around. For this reason, the undissolved particles adhering to the inner surface of the cylindrical screen 45 are pressed between the inner surface of the cylindrical screen 45 and the pressing member 46, and the polymer chains are separated from the swollen portion of the surface layer of the undissolved particles. The polymer chain passes through the cylindrical screen 45 together with the flocculant solution and flows into the secondary chamber 44B.

  As long as the pressure pump 15 of the flocculant solution transfer pipe 14 is operating, the flocculant solution flowing into the secondary chamber 44B is supplied from the flocculant solution outlet 40C of the cylindrical container 40 at a constant flow rate. To leak. The flocculant solution is supplied from the flocculant solution supply pipe 16 to the treated sludge in the sludge supply pipe 2. At this time, the flocculant solution supply pipe 16 flows through the flocculant solution supply pipe 16. The viscosity of the flocculant solution is measured, and the measured value signal is transmitted to the controller 6, so that the controller 6 controls the rotational speed of the driving device 48 as described above. By controlling the rotation speed, the sludge to be treated in the sludge supply pipe 2 pumped to the sludge dewatering machine 1 by the sludge supply pump 2A of the sludge supply pipe 2 has the optimum viscosity from the flocculant solution supply pipe 16 and the optimum coagulation performance. A flocculant solution is injected.

  In this way, the treated sludge into which the flocculant solution having the optimum coagulation performance is injected is sent from the sludge supply pipe 2 to the sludge dewatering machine (centrifugal dewatering machine in FIG. 1) 1. The treated sludge is efficiently separated into the dehydrated sludge and the separated liquid by the flocculant solution in the treated treated sludge, and the dehydrated sludge is discharged out of the system from the dehydrated sludge discharge port 1A of the sludge dehydrator 1, The separation liquid is discharged out of the system from the separation liquid discharge port 1B.

As described above, according to the sludge dewatering apparatus of the first embodiment, when the flocculant such as particles is dissolved in the dissolved water to generate the flocculant solution, Are mixed by stirring with a stirrer 12 to produce a flocculant solution, and further, the flocculant solution is taken into the cylindrical screen 45 by the flocculant dissolver 4 and screen-filtered. The configuration in which the controller 6 controls the operation of the flocculant dissolver 4 based on the result of measuring the viscosity of the flocculant solution flowing out from the agent dissolver 4 with the viscometer 5 has the following effects.
(1) The flocculant solution has a characteristic that the agglomeration performance varies depending on the degree of dissolution in the dissolved water, and the correlation between the dissolution condition and the agglomeration performance varies depending on the type of the aggregating agent to be used. Further, the degree of dissolution of the flocculant solution has a correlation with the viscosity. That is, there is a correlation between the viscosity of the flocculant solution and the aggregation performance. From this correlation, the viscosity at which the coagulant solution exhibits optimum coagulation performance is specified as an optimum value and stored in the controller 6 in advance, and the coagulant dissolver 4 is operated according to the measured value of the viscometer 5. By controlling the above, it becomes possible to always supply the coagulant solution having the optimum coagulation performance to the treated sludge in the sludge supply pipe 2, and there is an effect that the dewatering performance is greatly improved.
(2) Since the viscosity is measured as an indicator of the degree of dissolution of the coagulant solution and the operation of the coagulant dissolver 4 is adjusted by the controller 6 according to the measured value, the coagulant supplied to the treated sludge Even if the type is changed, the flocculant solution with the optimum flocculant performance can be generated and supplied immediately, and it is more responsive than the conventional flocculant dissolver, and it can maintain high dehydration performance at all times. is there.
(3) Even if the water quality changes due to fluctuations in the water temperature, the dissolution of the flocculant in the flocculant solution stirred and mixed in the flocculant solution tank changes with the flocculant dissolver. The measured flocculant solution is measured with a viscometer, and the controller controls the operation of the flocculant dissolver, so that the flocculant solution dissolved by the flocculant dissolver becomes over-stirred or under-stirred. There is an effect that the coagulation performance is prevented from being lowered, and the coagulant solution having the optimum dissolution condition and the optimum coagulation performance can be constantly generated and supplied to the treated sludge.
(4) Even when the amount of the flocculant solution injected into the treated sludge is increased or decreased, the controller 6 adjusts the operation of the flocculant dissolver 4 according to the measured value of the viscometer 5 of the flocculant solution. Even if the amount of the flocculant solution flowing into the flocculant dissolver 4 changes, there is an effect that the flocculant solution having the optimum flocculant performance can be supplied.
(5) When manually adjusting a conventional flocculant dissolver, it is difficult for even a skilled worker to adjust so as to obtain an optimal dissolution condition, and the rotational speed is slightly lower than the optimal value. If adjusted, there is a concern about insufficient dissolution of the flocculant, and therefore, the number of rotations is usually adjusted to be slightly higher than the optimum value, and it seems to be over-stirred. Moreover, even if it is the flocculant solution produced | generated by the state of an over-stirring state and the flocculant performance fell a little, in order to exhibit high flocculant performance, more flocculant solution is supplied to to-be-processed sludge. In the sludge dewatering apparatus according to the first embodiment, it is possible to prevent the flocculant dissolving machine 4 from being over-stirred, so that it is not necessary to supply the flocculant solution to the treated sludge more than a predetermined amount, and the running cost is reduced. There is an effect that can be reduced.
(6) Since the operation of the flocculant dissolver 4 can be maintained in an optimum state by the viscometer 5 and the controller 6, the operation of the flocculant dissolver has been adjusted manually. Compared with the case where the adjustment is made to be more excessive than the optimum state, the power consumption can be reduced and the wear of the parts can also be reduced.
(7) The flocculant solution produced by stirring and mixing the flocculant and the solution in the flocculant solution tank 3 is introduced into the cylindrical container 40 of the flocculant dissolver 4 and filtered through the cylindrical screen 45. Since the undissolved particles of the flocculant adhering to the inner surface of the cylindrical screen 45 are pressed and dissolved by the pressing member 46, the flocculant solution with the undissolved particles remaining is supplied to the treated sludge. This has the effect of preventing the undissolved particles from being dissolved.
(8) The controller 6 is configured to control the rotation of the driving device 48 of the coagulant dissolving machine 4 according to the measured value of the viscosity of the coagulant solution measured by the viscometer 5, so that the driving device 48 is The speed of moving along the inner surface of the cylindrical screen 45 of the pressing member 46 applying the moving force via the holding members 47A and 47B can be adjusted, and the effect of being able to perform a dissolution process with excellent responsiveness can be achieved. is there.

Embodiment 2. FIG.
FIG. 4 is a configuration diagram showing the sludge dewatering device according to Embodiment 2, and the same parts as those in FIG. Further, since the flocculant dissolving machine 4 has the same structure as that of the first embodiment, the sectional view taken along the line AA in FIG. 2 and the sectional view taken along the line BB in FIG. The sludge dewatering apparatus according to the second embodiment is greatly different from the first embodiment in that the concentrated liquid flocculant is supplied from the flocculant supply machine 7 into the flocculant solution tank 3.

  The flocculant supply machine 7 in the sludge dewatering device according to the second embodiment sucks the flocculant storage tank 74 that stores the concentrated liquid flocculant, and the condensed liquid flocculant in the flocculant storage tank 74 to agglomerate. It has a structure provided with a suction pump 71 for supplying it into the agent solution tank 3. A suction pipe 72 that hangs down in the coagulant of the coagulant storage tank 74 is connected to the suction port of the suction pump 71, and a coagulant supply pipe 73 that is connected to the coagulant solution tank 3 is connected to the discharge port of the suction pump 71. Has been. The suction pump 71 is started and stopped by an output signal from the controller 6.

  The action of the sludge dewatering device in the second embodiment is that the concentrated liquid coagulant stored in the coagulant storage tank 74 of the coagulant supply machine 7 is supplied into the coagulant solution tank 3 by the suction pump 71. This is performed in the same manner as in the first embodiment. Various pumps can be applied to the suction pump 71. However, the concentrated liquid flocculant has a high viscosity and is relatively highly corrosive. A tube pump with no surface in contact with the pumping flocculant is optimal.

  As described above, according to the sludge dewatering device of the second embodiment, the concentrated liquid flocculant is supplied from the flocculant supply machine 7 into the flocculant solution tank 3. The same effects as those of the first embodiment can be obtained even when is applied. In particular, when a concentrated liquid polymer flocculant is used, the polymer chains are entangled even if they are liquid, and the polymer chains are not diffused in a short time when supplied to the dissolved water. Only by stirring and mixing in the flocculant solution tank 3, a certain amount of time is required for the polymer chains to be dispersed in the liquid. The polymer chain is stirred and mixed in the flocculant solution tank 3 and dissolved by the flocculant dissolver 4. The structure to be treated has a problem that the polymer chain is more easily diffused than the flocculant such as a granular material, so that it is easily over-stirred. In the case of the configuration of the sludge dewatering apparatus according to the second embodiment, the controller 6 based on the viscosity measurement value of the flocculant solution from the viscometer 5 and the speed at which the polymer chains are dispersed by the flocculant dissolver 4. The flocculant solution is prevented from being over-stirred, and the flocculant solution having the optimum flocculation performance can be supplied to the treated sludge.

Embodiment 3 FIG.
FIG. 5 is a block diagram showing the sludge dewatering device in Embodiment 2, and the same parts as those in FIG. Further, since the flocculant dissolving machine 4 has the same structure as that of the first embodiment, the sectional view taken along the line AA in FIG. 2 and the sectional view taken along the line BB in FIG. In the sludge dewatering device according to the third embodiment, a flocculant solution storage tank 17 is disposed downstream of the viscometer 5 of the flocculant solution supply pipe 16 in the first embodiment, and the viscosity is measured by the viscometer 5. The pump 18 is provided in the flocculant solution supply pipe 16 between the inside of the bottom part of the flocculant solution storage tank 17 and the sludge supply pipe 2 so that the flocculant solution thus prepared is temporarily stored. Thus, the point that the flocculant solution in the flocculant solution storage tank 17 is supplied to the sludge to be treated in the sludge supply pipe 2 is significantly different from that of the first embodiment.

  The action of the sludge dewatering device in Embodiment 3 is that the viscosity of the flocculant solution flowing out from the flocculant supply machine 7 is measured with the viscometer 5 and then temporarily stored in the flocculant solution storage tank and added again with the pump 18. Except for being compressed and supplied to the sludge to be treated in the sludge supply pipe 2, the same operation as in the first embodiment is performed. Instead of installing the viscometer 5 in the flocculant solution supply pipe 16, the viscosity measuring unit is installed so as to come into contact with the flocculant solution in the flocculant solution storage tank 17, and the flocculant solution storage tank It is also possible to control the operation of the aggregating agent dissolver 4 by measuring the viscosity of the aggregating agent solution in 17. The configuration of the sludge dewatering device provided with the flocculant solution storage tank 17 and the pump 18 according to the third embodiment is also applicable to the sludge dewatering device using the concentrated liquid flocculant according to the second embodiment. is there.

  As described above, according to the sludge dewatering device of the third embodiment, in addition to the same effects as those of the first embodiment, there are the following effects. Immediately after the flocculant dissolver 4 is started, the control of the flocculant dissolver 4 is unstable, and the dissolution concentration of the flocculant solution that has been subjected to the dissolution treatment tends to vary for a while. The flocculant solution sent from the flocculant dissolver 4 is configured to be temporarily stored in the flocculant solution storage tank 17 so as to be dissolved while being stored in the flocculant solution storage tank 17. There is an effect that the flocculant solutions having different concentrations are mixed and the flocculant solution having the optimum dissolution concentration can be supplied to the sludge to be treated.

  Further, in the sludge dewatering apparatus according to the first embodiment, a plurality of sludge dewatering machines 1 are installed, the sludge supply pipe 2 is branched, and the sludge dewatering apparatus 1 is supplied with the sludge to be treated to perform the dewatering process. In the case of the configuration, the flocculant solution is more suitable when the flocculant solution supply pipe 16 of the flocculant dissolver 4 is branched so that the flocculant solution is supplied to the treated sludge immediately before being supplied to the sludge dewatering machine 1. Works effectively. This is because when the flocculant solution supply pipe 16 is connected to the sludge supply pipe 2 before the branch pipe and the flocculant solution is supplied, the flocculant solution comes into contact with the treated sludge and the particles of the sludge suspended material are aggregated. After the sludge flocs are formed, the sludge flocs are easily broken by moving in the sludge supply pipe 2 by the pressure of the sludge supply pump 2A, and the treated sludge is supplied into the sludge dewatering machine 1 as it is. The reason is that the dehydration efficiency is not improved. However, when the flocculant solution supply pipe 16 is branched and supplied to each branch pipe of the sludge supply pipe 2, the pumping force of the flocculant solution depends on one of the pumps 15, and Since it is difficult to make the pipe length and pipe resistance between the branch pipes of the flocculant solution supply pipe 16 the same, the supply amount of the flocculant solution to each branch pipe of the sludge supply pipe 2 is difficult to be equalized. There's a problem.

  In the sludge dewatering system of the third embodiment, the flocculant solution that has been dissolved by the flocculant dissolver 4 and whose viscosity has been measured by the viscometer 5 is temporarily stored in the flocculant solution storage tank 17, and the flocculant solution supply pipe The flocculant solution is reliably pressurized by each pump provided in each of the 16 branch pipes, and can be configured to be supplied to the treated sludge of each branch pipe of the sludge supply pipe 2. A necessary amount of the flocculant solution can be reliably supplied to the sludge to be treated. Thereby, the flocculant solution tank 3 provided with the stirrer 12, the flocculant dissolver 4 and the like can be supplied to a plurality of sludge dewaterers in one set, and high dewatering performance can be maintained. There is an effect.

Embodiment 4 FIG.
FIG. 6 is a block diagram showing a sludge dewatering device according to the fourth embodiment. The same parts as those in FIG. Further, since the flocculant dissolving machine 4 has the same structure as that of the first embodiment, the sectional view taken along the line AA in FIG. 2 and the sectional view taken along the line BB in FIG. In the sludge dewatering device according to the third embodiment, a so-called in-machine injection type centrifugal dewatering device having a flocculant inlet 1C in the sludge inflow pipe portion 1D is applied as the sludge dewatering device 1, and downstream of the flocculant solution supply pipe 16. The point which made the structure which connected the side edge part to the coagulant | flocculant inflow port 1C differs greatly from the said Embodiment 1. FIG. The other structure is the same as that of the first embodiment.

  In the case of a centrifugal dehydrator of the type that supplies the flocculant solution to the treated sludge in the normal sludge supply pipe 2, the sludge floc is formed by the aggregating action of the flocculant solution during the transfer through the sludge supply pipe 2. When the treated sludge is supplied into the outer drum of a centrifugal dehydrator rotating at a high speed, the sludge flocs are agitated by the acceleration force of the high-speed rotation and the dewatering performance is deteriorated. Usually, as a countermeasure, in order to re-form sludge flocs once collapsed in the outer cylinder, the supply amount of the flocculant solution to the treated sludge is previously excessively supplied more than necessary. As a result, it is possible to leave a flocculant that has not yet exhibited the coagulation action even after sludge flocs are formed in the sludge to be treated in the sludge supply pipe 2, and the treated sludge remains in the outer cylinder. When the sludge floc is supplied and the sludge floc is collapsed, the remaining flocculant exerts the aggregating action to form the sludge floc again, so that the dewatering performance in the centrifugal dehydrator can be maintained at a high level. However, this method has a problem that the running cost increases because it is necessary to supply the flocculant solution excessively.

  An in-flight injection type centrifugal dehydrator has been developed to solve such problems. This centrifugal dehydrator is a double pipe comprising an inner pipe and an outer pipe, and a sludge inflow pipe portion 1D that is partially inserted into the outer cylinder and receives the treated sludge from the sludge supply pipe 2 and supplies it into the outer cylinder. It has a structure. In addition, a flocculant inlet 1C to which the flocculant solution supply pipe 16 is connected is provided on the outer peripheral surface of the outer pipe at a portion not inserted into the outer cylinder, and the sludge to be treated flows through the inner pipe, and the inner pipe and the outer pipe. The flocculant solution flows in the space between the two. As a result, the sludge to be treated and the flocculant solution come into contact with each other when supplied to the outer cylinder, and are quickly mixed by the acceleration force of the outer cylinder, so that sludge flocs are formed there. The in-machine injection type centrifugal dehydrator has the effect that the running cost can be significantly reduced without excessive supply of the flocculant solution.

  The operation of the sludge dewatering apparatus in the fourth embodiment is performed in the same manner as in the first embodiment. The configuration of the sludge dewatering apparatus according to the fourth embodiment can be applied to the sludge dewatering apparatuses according to the second and third embodiments.

  As described above, according to the sludge dewatering device of the fourth embodiment, in addition to the effect that the flocculant solution shown in the first embodiment can exhibit the optimum coagulation performance, By applying an injection-type centrifugal dehydrator, the supply amount of the flocculant solution can be suppressed, so even if the supply amount of the flocculant solution is significantly reduced, high dewatering performance can be maintained and running There is an effect that the cost can be greatly reduced.

Embodiment 5. FIG.
FIG. 7 is a block diagram showing the sludge dewatering device according to the fifth embodiment. The same parts as those in FIG. Further, since the flocculant dissolving machine 4 has the same structure as that of the first embodiment, the sectional view taken along the line AA in FIG. 2 and the sectional view taken along the line BB in FIG. The sludge dewatering device according to the seventh embodiment is provided with a water quality measuring device 31 for measuring the water quality of the separated liquid discharged from the sludge dewatering device 1 in the sludge dewatering device according to the first embodiment. And very different.

  The water quality measuring device 31 in the sludge dewatering device according to the fifth embodiment includes a separation liquid receiving container 32 that receives the separation liquid discharged from the separation liquid discharge port 1B of the sludge dewatering machine 1, and a side portion of the separation liquid receiving container 32. A separation liquid discharge pipe 33 for discharging the separation liquid from the separation liquid receiving container 32 to the outside of the system, and a separation liquid bypass connected across the bottom of the separation liquid receiving container 32 and the middle portion of the separation liquid discharge pipe 33 A pipe 34 and a sampling pump 35 for sampling the separated liquid provided in the separated liquid bypass pipe 34 are provided, and a turbidimeter 36 is provided in the separated liquid bypass pipe 34. The turbidimeter 36 measures the turbidity of the separated liquid and transmits a turbidity measurement value signal to the controller 6.

  As the turbidimeter 36, for example, as shown in FIG. 7, a part of the separation liquid bypass pipe 34 is made of a transparent material such as quartz glass, and the outside of the pipe peripheral wall is irradiated with light such as laser light. A configuration in which a light sensor including a light emitting unit and a light receiving unit for measuring the amount of received light is installed, and a reflecting plate is installed on the opposing pipe peripheral wall is applicable. In this case, light is emitted from the light emitting part of the optical sensor toward the separation liquid in the tube and reflected by the reflector, and the amount of light attenuated by measuring the amount of light that has passed through the separation liquid and attenuated is received by the light receiving part. From this, the turbidity of the separated liquid is measured. However, the turbidimeter 36 is not limited to this configuration, and may have any configuration such as a turbidimeter using ultrasonic waves as long as the turbidity of the separated liquid can be measured. On the other hand, the controller 6 is preset with the optimum viscosity value of the flocculant solution and the optimum turbidity value of the separation liquid. The optimum viscosity value and the optimum turbidity value serve as a reference for determining the quality of the measured viscosity value of the flocculant solution and the measured turbidity value of the separated liquid.

  Next, the operation of the sludge dewatering device in the fifth embodiment will be described. In addition, since the effect | actions other than the control system by the water quality measuring device 31 and the controller 6 are the same as that of the said Embodiment 1, description is abbreviate | omitted. The separated liquid discharged from the separated liquid discharge port 1B of the sludge dewatering machine 1 is received in the separated liquid receiving container 32. A part of the separation liquid received in the separation liquid receiving container 32 is taken into the flow path on the side of the separation liquid bypass pipe 34 when the sampling pump 35 is started, rejoins the separation liquid discharge pipe 33 and is discharged outside the system. Is done. At this time, the turbidity of the separated liquid flowing through the separated liquid bypass pipe 34 is measured by the turbidimeter 36 of the water quality measuring device 31, and the turbidity measurement value signal is transmitted to the controller 6. The controller 6 compares the turbidity measurement value with the turbidity optimum value set in the controller 6 to determine whether the turbidity measurement value is equal to or greater than the turbidity optimum value. As a result, when the measured turbidity value is equal to or greater than the optimum turbidity value, it is determined that the supply amount of the flocculant is insufficient, and the rotation speed of the pressure feed pump 15 is increased so that the flocculant solution is added to the treated sludge. Control to increase the supply amount.

  At this time, since the pumping amount of the pumping pump 15 is increased, the supply amount of the coagulant solution to the coagulant dissolving machine 4 is also increased, and the rotation speed of the coagulant dissolving machine 4 is not an optimum value. Based on the measured viscosity value of the flocculant solution, the controller 6 re-adjusts the rotational speed of the flocculant dissolver 4. The configuration of the sludge dewatering apparatus according to the fifth embodiment can also be applied to the sludge dewatering apparatuses according to the second to fourth embodiments.

  As described above, according to the sludge dewatering device of the fifth embodiment, the rotational speed of the coagulant dissolver 4 is determined from the viscosity of the coagulant solution measured by the viscometer 5 as in the sludge dewatering device of the first embodiment. It is controlled by the controller 6 and the separation liquid discharged from the sludge dewatering machine 1 is received in the separation liquid receiving container 32 and discharged outside the system by the separation liquid discharge pipe 33 to separate a part of the separation liquid. By taking in the water quality measuring device 31 with the liquid bypass pipe 34 and measuring with the turbidimeter 36 and controlling the pumping pump 15 according to the measured turbidity, various effects shown in the first embodiment are obtained. In addition, when the property of the sludge to be treated supplied from the sludge supply pipe 2 is greatly changed, the flocculant solution having the optimum coagulation performance can be supplied to the treated sludge with the optimum supply amount. Thereby, there exists an effect which can maintain the dewatering efficiency in the sludge dehydrator 1 always in a high state, and can obtain the separation liquid with favorable water quality.

Embodiment 6 FIG.
FIG. 8 is a block diagram showing the sludge dewatering device according to the sixth embodiment. The same parts as those in FIG. Further, since the flocculant dissolving machine 4 has the same structure as that of the first embodiment, the sectional view taken along the line AA in FIG. 2 and the sectional view taken along the line BB in FIG. The sludge dewatering device according to the sixth embodiment is greatly different from the sludge dewatering device according to the fifth embodiment in that an inclined screen concentrator, which is a kind of sludge dewatering device in a broad sense, is applied as the sludge dewatering device 20. Other configurations are the same as those of the fifth embodiment.

  The sludge dewatering machine 20 according to the sixth embodiment includes a sludge dewatering container 21 having a rectangular cross section installed so as to be inclined so that the connection side of the sludge supply pipe 2 is lowered, and the sludge dewatering container 21 in the sludge dewatering container 21. 21 is provided with a planar dewatering screen 22 that is inclined and rotated in the same direction as 21, and a screen driver 23 that rotationally drives the dewatering screen 22. The interior of the sludge dewatering container 21 is divided into an upper sludge introduction chamber 24 and a lower separation liquid chamber 25 by a dewatering screen 22. A fixed scraper 26 adjacent to the upper surface of the dewatering screen 22 is attached to the sludge dewatering vessel 21 on the upper side of the slope of the dewatering screen 22 in the sludge introduction chamber 24.

  The sludge dewatering container 21 includes a sludge introduction pipe 27 that introduces the sludge to be treated from the sludge supply pipe 2 to a position slightly below the intermediate height of the slope of the dewatering screen 22 in the sludge introduction chamber 24, and the sludge introduction chamber 24. The dewatering sludge discharge pipe 28 for discharging the dewatered sludge squeezed by the fixed scraper 26 connected to the upper side of the inclination gradient of the dewatering screen 22 is connected to the separation liquid chamber 25 at the lower end side of the inclination gradient and separated. And a separation liquid discharge pipe 29 for discharging the liquid. In addition, a separation liquid receiving container 32, a separation liquid bypass pipe 33, and a water quality measuring device 31 are disposed at the opening end of the separation liquid discharge pipe 29, as in the case of the fifth embodiment.

  Next, the operation of the sludge dewatering device in the sixth embodiment will be described. Formation of the flocculant solution in the flocculant solution tank 3, supply of the flocculant solution from the flocculant solution tank 3 to the flocculant dissolver 4 by the pressure pump 15, and dissolution of the flocculant solution in the flocculant dissolver 4 Since the processing and the rotational speed control of the driving device 48 based on the viscosity measurement value of the flocculant solution by the viscometer 5 are performed in the same manner as in the first embodiment, detailed description thereof is omitted.

The treated sludge in which the coagulant solution is injected from the coagulant solution supply pipe 16 into the treated sludge pumped by the sludge supply pump 2A of the sludge supply pipe 2 passes through the sludge transfer pipe 27 of the sludge dewatering machine 20 and sludge. It is introduced into the sludge introduction chamber 24 of the dehydration container 21. In the treated sludge introduced into the sludge introduction chamber 24, moisture passes through the dewatering screen 22 and dehydrated sludge remains on the upper surface of the dewatering screen 22. Since the dewatering screen 22 with the dewatered sludge adhering to the upper surface is rotationally driven by the screen drive unit 23, the dewatered sludge on the upper surface of the dewatered screen 22 is scraped up by a fixed scraper 26 at a fixed position, and dehydrated sludge along the fixed scraper 26. It is transferred to the discharge pipe 28 and discharged out of the system.
On the other hand, the water that has passed through the dewatering screen 22 becomes a separated liquid from which sludge suspended substances have been removed, and is discharged from the open end of the separated liquid discharge pipe 29 to the separated liquid receiving container 32.

  Since the matters relating to the measurement of the turbidity of the separation liquid after the separation liquid bypass pipe 33 and the matters relating to the control of the pumping pump 15 according to the turbidity of the separation liquid are the same as those of the sludge dewatering device of the fifth embodiment, Detailed description is omitted. In the sixth embodiment, an inclined screen concentrator is applied to the sludge dewatering machine 20, but the sludge to be treated is dewatered even if the dewatering performance is somewhat inferior to that of the centrifugal dewatering machine such as other sludge concentrators. Any configuration can be applied as long as it can be separated into the separation liquid.

  As described above, according to the sludge dewatering apparatus of the sixth embodiment, the same effect as that of the fifth embodiment can be obtained for the inclined screen concentrator. Further, the inclined screen concentrator consumes less power than the centrifugal dehydrator, and has the effect of reducing the running cost associated with the operation of the sludge dewatering device.

Embodiment 7 FIG.
FIG. 9 is a block diagram showing the sludge dewatering device according to the seventh embodiment. The same parts as those in FIG. Further, since the flocculant dissolving machine 4 has the same structure as that of the first embodiment, the sectional view taken along the line AA in FIG. 2 and the sectional view taken along the line BB in FIG. In the sludge dewatering apparatus of the sixth embodiment, the turbidity of the separated liquid flowing out from the sludge dewatering machine 20 to the separated liquid discharge pipe 29 is measured by the water quality measuring device 31, but the sludge dewatering of the seventh embodiment is performed. The apparatus is greatly different in that the viscosity of the dewatered sludge flowing out from the sludge dewatering machine 20 to the dewatered sludge discharge pipe 28 is measured by the viscometer 30 instead.

  The dewatered sludge discharge pipe 28 is provided with a sludge viscometer 30 for measuring the viscosity of the dewatered sludge discharged from the sludge introduction chamber 24 of the sludge dewatering machine 20, and the sludge viscometer 30 is a signal for measuring the viscosity of the dehydrated sludge. Is transmitted to the controller 6. In the case of the sludge dewatering machine 1 having high dewatering efficiency such as the centrifugal dewatering machine shown in the first embodiment, the dewatered sludge discharged from the dewatered sludge discharge port 1A has a low water content and is discharged in a state close to a lump. It is difficult to achieve viscosity with a viscometer. In contrast, in the case of the sludge dewatering machine 20 such as the inclined screen concentrator shown in the seventh embodiment, the dehydrated sludge discharged from the dewatered sludge discharge pipe 28 is high enough to allow the water content to flow. It is possible to measure the viscosity with a viscometer. In the controller 6, the optimum viscosity value of the flocculant solution and the optimum viscosity value of the dewatered sludge are stored and set in advance. Thus, the controller 6 in which the optimum viscosity values of the flocculant solution and the dewatered sludge are set in advance, by receiving the viscosity measurement value signal from each of the viscometer 5 and the sludge viscometer 30 of the flocculant solution, The optimum viscosity value and the measured viscosity value of the flocculant solution and the dewatered sludge are compared, and the operation of the flocculant dissolver 4 and the pressure pump 15 is controlled based on the difference.

  Regarding the action of the sludge dewatering device in the seventh embodiment, the control is performed except that the controller 6 controls the pumping amount of the flocculant solution of the pumping pump 15 based on the viscosity measurement value of the dewatered sludge by the sludge viscometer 30. Since the process is performed in the same manner as in the sixth embodiment, detailed description thereof is omitted.

  As described above, according to the sludge dewatering device of the seventh embodiment, in addition to the effects shown in the sixth embodiment, the sludge viscometer 30 is used, which is less expensive than the case where the water quality measuring device 31 is used. Since the viscosity is measured and the pumping pump 15 is controlled based on the measured value to control the supply amount of the flocculant solution to the sludge to be treated, the initial cost can be reduced. .

The results when the sludge is actually dehydrated using the configuration of the sludge dewatering apparatus shown in the first embodiment will be described below. This Example 1 was performed on the following implementation conditions.
[Conditions for implementation]
・ Flocculant solution tank 3 capacity: 1.4m3
・ Agitator 12: 2.2 kW
・ Dissolved water: treated water at sewage treatment facility, supply amount 167 L / min
Flocculant: Granular cationic polymer flocculant trade name “Hi-Moflock MP-184”,
Supply amount 367 g / min
・ Pressure pump 15: Single screw pump Discharge flow rate 120L / min, power 3.7kW
・ Flocculant dissolver 4: Driver 48 Uses an electric motor and controls the rotation speed with an inverter.
(Control frequency range 17-42Hz)
・ Flocculant solution: Solution concentration 0.22%, chemical injection rate 1.0% / TS
・ Viscometer 5: Measurement principle Rotation type ・ Sludge dehydrator 1: Centrifugal dehydrator Setting differential speed 5.4min-1
・ Sludge supply to sludge dewatering machine: 50m3 / h

  The viscosity of the flocculant solution is measured with the viscometer 5, and the rotation of the flocculant dissolver 4 is controlled with the controller 6 based on the measured viscosity value. In order to maintain the formation of the flocculant solution, it is necessary to carry out prior verification to select the optimum viscosity value of the flocculant solution to be used. For this reason, as prior verification, while the viscosity of the flocculant solution after the dissolution treatment with the flocculant dissolver 4 is measured with the viscometer 5, the frequency of the inverter control is manually adjusted by the drive unit 48 to adjust the frequency of the flocculant dissolver 4. The rotation is adjusted to produce a coagulant solution having a predetermined viscosity (90 mPas, 100 mPas, 110 mPas, 120 mPas), the coagulant solution having each viscosity is supplied into the treated sludge, and dewatered by the sludge dehydrator 1. The moisture content of sludge was measured. As a result of creating a correlation diagram between the flocculant solution viscosity and the moisture content of the dewatered sludge (see FIG. 10), the granular cationic polymer flocculant used this time has a viscosity of 110 mPas at a solution concentration of 0.22%. It was found that the highest aggregating performance was exhibited when the rotational speed of the aggregating agent dissolver 4 was controlled so as to be a value.

  Actually, 110 mPas was selected and input to the controller 6 as the optimum viscosity value in the sludge dewatering apparatus having the configuration of the first embodiment. Then, the controller 6 performs inverter control of the rotational speed of the driving device 48 so that the viscosity of the flocculant solution after the dissolution treatment by the flocculant dissolver 4 becomes an optimum viscosity value, and the flocculant solution subjected to the dissolution treatment is controlled. The treated sludge supplied in a predetermined amount was dehydrated by continuously operating the sludge dewatering machine 1. FIG. 11 shows a time-series diagram regarding the viscosity measurement value of the flocculant solution measured with the viscometer 5 and the moisture content of the dewatered sludge. In addition, as a comparison object, the rotational speed of the driving device 48 of the flocculant dissolving machine 4 is set to a constant value under the same implementation conditions (when the flocculant solution having a viscosity measurement value of 110 mPas is generated in the previous verification measurement). The number of rotations of the driving machine 48 was fixed, and the sludge to be treated was dehydrated by the sludge dewatering device. FIG. 12 shows a time-series diagram regarding the measured viscosity value of the flocculant solution measured with the viscometer 5 and the moisture content of the dewatered sludge.

  In the case of the sludge dewatering device in which the rotational speed of the driving machine 48 is maintained at a constant value, as is apparent from the time series diagram of FIG. 12, the coagulant solution over time after the operation of the coagulant dissolver 4 is stabilized. Viscosity measured value of fluctuates around ± 10 mPas. Various factors can be considered for this variation. One of them is a variation in water quality and a variation in water temperature due to the fact that the dissolved water is treated water obtained by purifying sewage in a sewage treatment facility. Despite the fact that the state of dissolution of the coagulant in the coagulant solution at the time of flowing into the coagulant dissolver 4 has fluctuated from the standard state (the state of dissolution at the time of prior verification), the drive unit 48 is operated at the same rotational speed. Since it will be dissolved, it may be over-stirred (2.0 to 4.0 hour) or under-stirred (5.0 to 7.0 hour). Since the coagulant solution at that time has a lower coagulation performance than in the optimum state, the moisture content of the dewatered sludge when this is supplied to the treated sludge has increased (the coagulant solution The moisture content of the dewatered sludge when the measured viscosity value is the optimum value of 110 mPas is as good as 78.3%, whereas the moisture content of the dehydrated sludge when the viscosity measured value of the flocculant solution is over 99 gPas and overstirring is 79.Pas. It has risen to 1%).

  On the other hand, in the case of the sludge dewatering device of Embodiment 1 in which the controller 6 controls the rotational speed of the driving device 48 in accordance with the viscosity measurement value sent from the viscometer 5, the time series of FIG. As is apparent from the figure, the fluctuation range from the optimum viscosity value of the flocculant solution over time after the operation of the collector dissolver 4 is stabilized is as small as ± 3 mPas (108 to 113 mPas) at maximum. This is because the viscosity measurement value measured by the viscometer 5 is controlled by the controller 6 when the dissolution condition of the flocculant varies from the standard state (dissolution condition at the time of preliminary verification) due to the water quality fluctuation or water temperature fluctuation. This is because, compared with the optimum viscosity value, the rotational speed of the driving device 48 is controlled, so that the stirring process is prevented from becoming over-stirred or under-stirred. By supplying the coagulant solution dissolved and treated with the optimum viscosity to the treated sludge at all times, the water content of the dehydrated sludge can be as good as 78.6% at the minimum. From the above implementation results, it can be said that the excellent operational effect of the sludge dewatering device of the first embodiment could be proved.

It is a block diagram which shows the sludge dehydration apparatus in Embodiment 1 of this invention. It is sectional drawing seen from the AA line direction shown in FIG. 3 of the coagulant | flocculant dissolver in Embodiment 1 of this invention. It is sectional drawing seen from the BB line direction shown in FIG. 2 of the coagulant | flocculant dissolver in Embodiment 1 of this invention. It is a block diagram which shows the sludge dehydration apparatus in Embodiment 2 of this invention. It is a block diagram which shows the sludge dehydration apparatus in Embodiment 3 of this invention. It is a block diagram which shows the sludge dehydration apparatus in Embodiment 4 of this invention. It is a block diagram which shows the sludge dehydration apparatus in Embodiment 5 of this invention. It is a block diagram which shows the sludge dehydration apparatus in Embodiment 6 of this invention. It is a block diagram which shows the sludge dehydration apparatus in Embodiment 7 of this invention. It is a correlation diagram which shows the relationship between the viscosity measured value of the coagulant | flocculant solution by prior verification in Example 1, and the moisture content of dewatered sludge. It is a time series figure about the viscosity measurement value of the flocculant solution at the time of controlling the number of rotations of driver 48 in Example 1 according to the viscosity measurement value, and the moisture content of dehydrated sludge. It is a time series figure about the viscosity measurement value of the flocculant solution at the time of fixing the number of rotations of driver 48 in Example 1 with a fixed value, and the moisture content of dehydrated sludge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sludge dewatering machine 1A Dehydrated sludge discharge port 1B Separation liquid discharge port 1C Coagulant inlet 1D Sludge inflow pipe part 2 Sludge supply pipe 2A Sludge supply pump 3 Coagulant solution tank 4 Coagulant dissolver 5 Viscometer 6 Controller 7 Coagulation Agent supply machine 70a Coagulant supply port 8 Drive machine 9 Supply port switch 10 Dissolved water supply pipe 11 Control valve 12 Stirrer 12A Drive machine 12B Rotating output shaft 12C Stirring blade 13 Water level gauge 14 Coagulant solution transfer pipe 15 Pressure feed pump 16 Flocculant solution supply pipe 17 Flocculant solution storage tank 18 Pump 20 Sludge dehydrator 21 Container 22 Screen 23 Screen driver 24 Sludge introduction chamber 25 Separation liquid chamber 26 Fixed scraper 27 Sludge transfer pipe 28 Dehydrated sludge discharge pipe 29 Separation liquid discharge pipe 30 Sludge viscometer 31 Water quality measuring device 32 Separation liquid receiving container 33 Separation liquid discharge pipe 34 Separation liquid bypass pipe 35 Sampling pump 36 Turbidimeter 40 Cylindrical container 40A, 40B Flange 40C Flocculant solution outlet 41A, 41B Flange lid 41C Flocculant solution inlet 42A, 42B Bolt / nut 43A, 43B Partition member 44A Primary chamber 44B Secondary chamber 45 Cylindrical screen 46 Pressing members 47A, 47B Holding member 48 Drive unit 48A Drive shaft 48B Reducer 49 Bearing 70 Hopper-like container 70a Coagulant supply port 71 Suction pump 72 Suction pipe 73 Coagulant supply pipe 74 Coagulant solution tank

Claims (1)

A sludge dewatering machine that separates the treated sludge into a separated liquid and a dewatered sludge;
A sludge supply pipe for supplying treated sludge to the sludge dewatering machine;
A flocculant solution tank that stirs and mixes the flocculant and dissolved water to form a flocculant solution;
A cylindrical container, a cylindrical screen that filters the flocculant solution disposed in the cylindrical container, one or more pressing members that press and dissolve the flocculant adhering to the inner surface of the cylindrical screen, A holding member that holds the pressing member; and a drive unit that moves the pressing member along the inner surface of the cylindrical screen via the holding member , introduces the flocculant solution, performs screen filtration, and flocculant solution. A flocculant dissolver for dissolving the flocculant therein,
A viscometer for measuring the viscosity of the flocculant solution flowing out of the flocculant dissolver;
According to the measured value of the viscometer,
A sludge dewatering device comprising a controller that controls the rotation of the drive machine that is activated and raised at a low speed .

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