JP5781173B2 - Chemical liquid distribution apparatus, chemical liquid injection system, and method of operating chemical liquid injection system - Google Patents

Description

  The present invention relates to a chemical solution distributor, a chemical solution injection system, and a method for operating the chemical solution injection system. For example, the chemical solution distribution device, the chemical solution injection system, and the like used for injecting a chemical solution such as sodium hypochlorite into clean water or sewage The present invention relates to a method for operating a chemical injection system.

  Patent Document 1 does not require a special power source, and as a liquid dropping device that drops a chemical solution at a constant dropping rate over a long period of time, a liquid dropping unit that is open to the atmosphere, a liquid tank unit that is a sealed structure, and an open air The liquid dripping part has a liquid dripping port at the bottom, and a liquid transfer hole is provided between the lower part of the liquid dripping part and the lower part of the liquid tank part. There is disclosed a liquid dropping device in which one end of an adjustment tube is passed through, the other end is opened at an arbitrary position inside the liquid dropping portion, and the liquid injection portion is connected to the lower portion of the liquid tank portion at the lower portion.

  In Patent Document 2, when the pump is operated after the pump is stopped and the aqueous sodium hypochlorite solution is transferred to the water supply pipe, the coagulated bubbles generated when the pump is stopped are transferred into the pump and the gas lock is applied to the pump. Has been disclosed, which solves the problem that the aqueous sodium hypochlorite solution cannot be stably supplied to the water supply pipe at a predetermined mass flow rate.

  The chemical solution supply apparatus includes a chemical solution storage tank that stores the chemical solution, a transfer pipe that supplies the chemical solution in the chemical solution storage tank to a supply location, and the transfer pipe that can transfer the chemical solution in the transfer pipe. A branch pipe branched from a position downstream of the pump of the transfer pipe, the transfer pipe having a branch part provided with the branch pipe, and an upstream side of the branch part. A first transfer pipe and a second transfer pipe on the downstream side of the branch portion, and the branch pipe is configured to return the chemical solution from the branch portion to the chemical solution storage tank. Switching that allows the distributed chemical solution to be transferred to either the second transfer pipe or the branch pipe as a transfer destination, and allows the transfer destination to be switched between the second transfer pipe and the branch pipe. A device is provided.

Japanese Patent Laid-Open No. 11-156178 JP 2013-146650 A

  In various water treatment plants including water and sewage facilities, it is necessary to adjust the discharge amount of the chemical solution according to the amount of water to be injected with the chemical solution so as to achieve an appropriate injection rate. The capacity of the chemical injection pumps and discharge valves used for that purpose is designed based on the planned water volume that looks at the overall plan of the water treatment plant, so in many cases water treatment that does not reach the planned water volume The capacity becomes excessive when the plant is started up.

  In the droplet dropping device described in Patent Document 1, it is difficult to dynamically adjust the supply amount of the chemical solution, and when the droplet dropping device is designed in advance so as to match the amount of droplets with the planned water distribution amount, In the case of a small amount less than the planned water distribution amount, there was a problem that the droplet amount could not be properly adjusted to a minute flow rate.

  Similarly, in the chemical solution supply apparatus described in Patent Document 2, since the capacity of the pump for injecting the chemical solution is determined based on the planned water amount in advance, the droplet amount is reduced in the case of a small amount less than the planned water distribution amount. There was a problem that the flow rate could not be adjusted appropriately.

  In such a case, in general, the discharge amount of the chemical must be adjusted by adjusting the opening of the discharge valve or controlling the rotational speed of the pump, but it is difficult to adjust the flow rate accurately by adjusting the opening of the discharge valve. Yes, when adjusting the rotational speed of the electric motor that drives the pump by the inverter, if the rotational speed is excessively reduced, the rotational speed of the cooling fan that is drivingly connected to the output shaft of the electric motor also decreases at the same time, resulting in insufficient cooling. There was a problem that the temperature of the motor rose abnormally.

  For this reason, there is a limit to the lower limit control of the discharge amount of the chemical liquid by adjusting the opening degree of the discharge valve and controlling the rotation speed of the electric motor, and there is a possibility of excessive chemical injection due to insufficient adjustment with respect to the insufficient water amount. Even the devices described in Patent Literature 1 and Patent Literature 2 cannot cope with such a problem, and there is a possibility that the chemical solution is excessively injected at the time of starting up the water treatment plant.

  The above-mentioned problems are not limited to chemical liquids for disinfection such as sodium hypochlorite, but in various water treatment plants where the amount of water is significantly smaller than the planned amount of water, such as iron-based and aluminum-based flocculants and methanol. It also occurs when various chemicals such as biological processing aids are injected.

  In view of the above-described problems, an object of the present invention is to provide a chemical solution distribution device, a chemical solution injection system, and a chemical solution injection system that can appropriately adjust the injection amount of a chemical solution even when the amount of water is significantly smaller than the planned water amount. The point is to provide a driving method.

In order to achieve the above-mentioned object, the first characteristic configuration of the chemical liquid distribution apparatus according to the present invention includes a chemical liquid inflow pipe and a chemical liquid return pipe connected to the chemical liquid tank, as described in claim 1 of the claims , A chemical solution supply pipe connected to a chemical solution injection section for injecting the chemical solution into a chemical solution injection target liquid processed in a seed water treatment plant, and a chemical solution inflow pipe having an amount more than a necessary supply amount to the chemical solution supply pipe So that the chemical liquid is supplied to the chemical liquid supply pipe without being interrupted, and is supplied toward the opening of the chemical liquid supply pipe, and the excess chemical liquid that has not been supplied to the chemical liquid supply pipe is supplied to the chemical liquid supply pipe. A chemical distribution mechanism for returning from the return pipe, and the chemical distribution mechanism is connected to the chemical inflow pipe, the chemical return pipe, and the chemical supply pipe, and stores the chemical overflowed from the opening to store the chemical liquid Supply to the chemical return pipe In that it includes a liquid tank.

Since the chemical liquid in the chemical liquid tank fed from the chemical liquid inflow pipe is supplied to the chemical liquid supply pipe so as not to be interrupted, the chemical liquid is stably injected from the chemical liquid supply pipe to the target of the chemical liquid injection through the chemical liquid injection section. . Even when the chemical solution fed from the chemical solution supply pipe overflows, it is received and stored in the chemical solution tank and returned to the chemical solution tank via the chemical solution return tube.
For example, by adjusting the diameter of the chemical solution supply pipe, even a small amount of chemical solution can be stably injected. And the excess chemical liquid that has not been supplied to the chemical liquid supply pipe, that is, the chemical liquid overflowing from the chemical liquid supply pipe is returned to the chemical liquid tank via the chemical liquid return pipe, so it is necessary to accurately control the liquid supply amount from the chemical liquid inflow pipe However, it is sufficient that at least the amount of the chemical solution that is required to be supplied to the chemical solution supply pipe is fed. For example, even when it is necessary to supply a chemical solution in an amount suitable for an extremely small amount of water than the planned water amount using a pump having a capacity corresponding to the planned water amount, even if the pumping amount cannot be accurately controlled, the above-mentioned By using this chemical solution distribution mechanism, the chemical injection amount can be adjusted appropriately.

  The second feature configuration is the chemical solution injected from the chemical solution injection section between the chemical solution supply pipe and the chemical solution injection section in addition to the first feature configuration described above, as described in claim 2. This is in that a minute flow rate adjusting mechanism for adjusting the amount is provided.

  According to the above-described configuration, a small amount of the chemical solution supplied from the chemical solution supply pipe is more accurately adjusted and supplied by the minute flow rate adjusting mechanism.

  In the third feature configuration, as described in claim 3, in addition to the first or second feature configuration described above, the chemical solution distribution mechanism may include a predetermined amount of the chemical solution fed from the chemical solution inflow pipe. Is distributed to the chemical solution supply pipe and has a chemical solution distribution pipe provided with a distribution flow rate adjusting valve for distributing excess chemical solution to the chemical return pipe.

  The chemical liquid sent from the chemical inflow pipe flows into the chemical distribution pipe and is distributed to the chemical supply pipe so that the required amount of chemical liquid is not interrupted by the distribution flow adjustment valve, so that the excess chemical liquid is distributed to the chemical return pipe. become.

The fourth characterizing feature of the can, as noted in the claim 4, in addition to the third characterizing feature described above, the chemical liquid supply pipe and the chemical return pipe is inserted into the bottom of the chemical tank, before Symbol The open end of the chemical solution supply pipe is located lower than the open end of the chemical return pipe.

Since the chemical liquid stored in the chemical liquid tank is injected such uninterrupted at the open end of the chemical solution supply pipe disposed lower than the open end of the drug solution return pipe, as stable injection state is maintained Become.

The fifth characterizing feature of the can, as noted in the claim 5, in addition to the first or second characteristic feature of the above, the chemical liquid supply pipe and the chemical return pipe is inserted into the bottom of the chemical tank , lies in the open end portion of the front Symbol chemical supply pipe is disposed so high than the opening end portion of the chemical return pipe.

  According to the above-described configuration, the chemical liquid fed from the chemical liquid inflow pipe is supplied to the chemical liquid supply pipe so as not to be interrupted. At that time, the chemical liquid overflowing from the chemical liquid supply pipe is stored in the chemical liquid tank, and flows into the chemical liquid tank by flowing in from the opening end of the chemical liquid return pipe arranged lower than the opening end of the chemical liquid supply pipe. Even when the supply amount of chemical solution from the chemical solution injection pipe is much larger than the required amount, it is possible to reliably return the excess chemical solution to the chemical solution tank while injecting the chemical solution with the appropriate injection amount to the injection target become. In addition, a minute flow rate adjusting mechanism is provided between the chemical solution supply pipe and the chemical solution injection section, and even if the flow rate of the chemical solution supply pipe is reduced to a very small flow rate, excess chemical solution that does not flow into the chemical solution supply pipe is supplied to the chemical solution tank. You will be able to return it.

  In the sixth feature configuration, as described in claim 6, in addition to the fourth or fifth feature configuration described above, the chemical tank includes a vent pipe for releasing the gas generated therein to the atmosphere. There is in point.

  Even in the case of a chemical solution that generates some kind of gas, it is opened to the atmosphere through the vent pipe, and it is possible to avoid the gas from filling the installation space of the chemical solution distribution device.

The first characteristic feature of the chemical liquid injection system according to the present invention, as described in the claim 7, and chemical tank, a chemical inlet pipe and chemical return pipe connected to the chemical liquid tank, in each type of water treatment plant A chemical solution supply pipe connected to a chemical solution injection section for injecting a chemical solution into the processed chemical solution injection target liquid, and a chemical solution in an amount more than a necessary supply amount to the chemical solution supply pipe are sent from the chemical solution inflow pipe. A chemical solution distribution mechanism that supplies an excess chemical solution that is supplied toward the opening of the chemical solution supply tube and that is not supplied to the chemical solution supply tube from the chemical solution return tube; and between the chemical solution supply tube and the chemical solution injection unit A fine flow rate adjusting mechanism that adjusts the amount of the chemical liquid injected from the chemical liquid injection section, and the chemical liquid distribution mechanism is connected to the chemical liquid inflow pipe, the chemical liquid return pipe, and the chemical liquid supply pipe, and overflows from the opening. The stored chemical solution In that it includes a chemical bath supplied to the liquid return pipe.

Since the chemical liquid in the chemical liquid tank sent from the chemical liquid inflow pipe is supplied to the chemical liquid supply pipe without interruption by the chemical liquid distribution mechanism, the appropriate amount of the chemical liquid supplied to the chemical liquid supply pipe via the micro flow rate adjustment mechanism Only precisely injected into the injection target. The surplus chemical liquid that has not been supplied to the chemical liquid supply pipe, that is, the chemical liquid overflowing from the chemical liquid supply pipe is received and stored in the chemical liquid tank, and is returned to the chemical liquid tank via the chemical liquid return pipe. It is not necessary to accurately control the amount of pumped liquid, and it is sufficient that at least the amount of chemical liquid higher than the necessary amount supplied to the chemical liquid supply pipe is pumped.

  In the second feature configuration, as described in claim 8, in addition to the first feature configuration described above, the micro flow rate adjusting mechanism includes a dropping flow meter having an open / close valve at a bottom portion, and the dropping flow rate. It is in the point comprised with the dripping amount adjustment valve arrange | positioned at the upper part of the meter.

  Adjust the drop amount adjustment valve while measuring the amount of drug solution dropped on the drip flow meter with the open / close valve closed, and then adjust the target injection amount by opening the open / close valve. It becomes possible to inject accurately.

  In the third feature configuration, as described in claim 9, in addition to the first or second feature configuration described above, the liquid feeding amount can be adjusted between the chemical solution tank and the chemical solution inflow pipe. It is in the point provided with a liquid feed pump.

  The injection flow rate can be adjusted to an appropriate level by the micro flow rate adjustment mechanism.For example, even with a liquid feed pump that cannot adjust the pumping volume accurately, it can be injected without any problem. The excess chemical solution can be returned to the chemical solution tank via the chemical solution return pipe.

  In the fourth feature configuration, as described in claim 10, in addition to the third feature configuration described above, the chemical solution fed to the chemical solution inflow pipe by the liquid feed pump is supplied to the chemical solution distribution mechanism. There is a branch pipe connected to the chemical liquid injection part without going through, and a switching valve for switching whether the chemical liquid is sent to the chemical liquid distribution mechanism or to the branch pipe.

  By operating the switching valve, it is possible to switch whether the chemical liquid fed to the chemical liquid inflow pipe by the liquid feed pump is sent to the chemical liquid distribution mechanism or to the branch pipe. When it is necessary to properly inject a small amount of chemical into the injection target, the switching valve is switched so that the chemical is distributed to the chemical distribution mechanism. For example, the chemical is injected into a sufficient amount of the injection target that substantially matches the planned water volume. In this case, since the liquid supply amount can be appropriately adjusted by the liquid supply pump, the switching valve may be switched so that the liquid is supplied to the branch pipe.

  The characteristic configuration of the operation method of the chemical injection system according to the present invention is the operation method of the chemical injection system having the fourth characteristic configuration described above, as described in claim 11, wherein the flow rate of the target liquid injection target liquid When the flow rate is lower than a predetermined flow rate, the switching valve is switched so that the chemical solution is supplied to the chemical solution distribution mechanism, and the injection amount of the chemical solution is adjusted by the micro flow rate adjustment mechanism. The switching valve is switched so that the chemical solution is fed to the branch pipe when there are many, and the injection amount of the chemical solution is adjusted by the liquid feeding pump.

  When the liquid delivery volume cannot be adjusted properly with the liquid delivery pump, that is, when the flow rate of the liquid to be injected is smaller than the predetermined flow rate, the minute flow rate can be adjusted by switching the switching valve so that the liquid is delivered to the chemical solution distribution mechanism. The injection amount of the chemical solution can be appropriately adjusted via the mechanism. In addition, when the flow rate of the liquid to be injected is higher than a predetermined flow rate, the liquid supply amount can be appropriately adjusted by the liquid supply pump by switching the switching valve so that the liquid is supplied to the branch pipe.

  As described above, according to the present invention, a chemical solution distribution device, a chemical solution injection system, and a method for operating the chemical solution injection system that can appropriately adjust the injection amount of the chemical solution even when the amount of water is significantly smaller than the planned water amount. Can now be provided.

Illustration of chemical injection system Explanatory drawing of the chemical injection system which shows another embodiment Explanatory drawing of the chemical injection system which shows another embodiment (A), (b) is explanatory drawing of the chemical | medical solution distribution apparatus which shows another embodiment Explanatory drawing of the chemical injection system which shows another embodiment

  Hereinafter, an embodiment of a chemical solution distribution device, a chemical solution injection system, and a method for operating the chemical solution injection system according to the present invention will be described. In the following embodiment, an example of a chemical liquid injection system that is used in a sewage treatment facility that purifies sewage and discharges it to a river or the like, and injects sodium hypochlorite, which is a chemical liquid for disinfection, into the purified treated water. Explained.

  When a new sewage treatment facility or water treatment facility is constructed or reconstructed, the planned water volume is set based on the overall plan that takes into account the future required water volume, etc., assumed at that time. Various equipment capacities and pipe diameters are designed to correspond to the planned water volume.

  For example, the chemical solution injection system for injecting disinfectant into sewage before being discharged into rivers, etc. is the same, and the chemical solution pump that sends the chemical solution injected from the chemical injection unit to the sewage in the mixing pond from the chemical tank is planned The pump capacity is determined so that a chemical solution corresponding to the amount of water can be injected.

  However, the amount of water is often much lower than the planned amount of water at the beginning of the plan, and it is very difficult to adjust the amount of water delivered by the chemical pump in order to inject an appropriate amount of chemical into such a small amount of sewage. In some cases, it was overloaded.

  According to the present invention, it is possible to realize a chemical solution distributor and a chemical solution injection system that can inject an appropriate amount of chemical solution even in such a case.

  As shown in FIG. 1, the chemical liquid injection system 1 includes a chemical liquid tank 2, a pumping pump 3, a discharge valve 4, a chemical liquid distributor 5, a minute flow rate adjusting mechanism 6, and the like. The pumping pump 3 is configured such that the rotation speed thereof can be controlled by the inverter control device 30.

  The chemical liquid distribution device 5 includes a chemical liquid distribution mechanism 50, a chemical liquid inflow pipe 51, a chemical liquid return pipe 52, and a chemical liquid supply pipe 53. The chemical solution distribution mechanism 50 includes a chemical solution tank 54, a chemical solution distribution pipe 55, a distribution flow rate adjustment valve 56, and the like. In the figure, the alternate long and short dash lines indicate the chemical solution inflow pipe 51, the chemical liquid return pipe 52, and the chemical liquid supply pipe 53, respectively. In practice, a resin-made flexible transparent tube is used.

  In the figure, reference numeral 57 denotes a vent pipe for releasing the gas generated inside the chemical tank 54 to the atmosphere, and a vent pipe 57 for releasing chlorine gas generated by decomposition of sodium hypochlorite to the atmosphere outdoors. is there.

  A chemical liquid inflow pipe 51, a chemical liquid return pipe 52, and a chemical liquid supply pipe 53 are inserted into the chemical liquid tank 54 so as to open upward at one end thereof. The chemical liquid inflow pipe 51 is connected to the chemical liquid tank 2 via the pumping pump 3 and the discharge valve 4, and is a pipe for pumping the chemical liquid from the chemical liquid tank 2 to the chemical liquid tank 54.

  The other end of the chemical liquid return pipe 52 is connected to the chemical liquid tank 2, and the excess chemical liquid in the chemical liquid tank 54 is dropped into the chemical liquid tank 2 and returned to the chemical liquid tank 2. Further, the chemical solution supply pipe 53 is connected to the chemical solution injection unit 7 at the other end, and supplies the chemical solution pumped up by the chemical solution inflow tube 51 from the chemical solution injection unit 7 to the mixing tank to be processed.

  The chemical liquid pumped up by the chemical liquid inflow pipe 51 is branched into two horizontal directions by the chemical liquid distribution pipe 55 connected to the pipe end, and injected into the upper opening of the chemical liquid supply pipe 53 and the upper opening of the chemical liquid return pipe 52, respectively. It is configured to fall down.

  In addition, a distribution flow rate adjustment valve 56 is provided on one side of the chemical solution distribution pipe 55 so that the flow rate of the chemical solution injected into the upper opening of the chemical solution supply pipe 53 is adjusted to a predetermined flow rate so that the chemical solution is not interrupted into the pipeline. It is comprised so that it may be dripped and supplied. Furthermore, the opening end portion of the chemical solution supply pipe 53 is disposed lower than the opening end portion of the chemical solution return pipe 52.

  The chemical solution supplied to the chemical solution supply pipe 53 is adjusted to a fixed amount by the minute flow rate adjusting mechanism 6 and then injected into the sewage in the mixing tank 10 from the chemical solution injection unit 7. As a result of the flow rate adjustment by the micro flow rate adjusting mechanism 6, the chemical liquid overflowing from the upper opening of the chemical liquid supply pipe 53 is temporarily stored in the chemical liquid tank 54, and the liquid level in the chemical liquid tank 54 rises from the upper opening position of the chemical liquid return pipe 52. Then, the chemical solution falls from the chemical solution return pipe 52 to the chemical solution tank 2 and returns.

  According to such a configuration, the chemical liquid stored in the chemical liquid tank 54 flows into the opening end portion of the chemical liquid supply pipe 53 disposed lower than the opening end portion of the chemical liquid return pipe 52 so as not to be interrupted. Therefore, the injection state of the chemical solution is maintained.

  As described above, the chemical liquid distributor 5 is configured to pump the liquid from the chemical liquid inflow pipe 51 and the chemical liquid return pipe 52 connected to the chemical liquid tank 2, the chemical liquid supply pipe 53 connected to the chemical liquid injection unit 7, and the chemical liquid inflow pipe 51. A chemical solution distribution mechanism 50 is provided that supplies the chemical solution supply pipe 53 to the chemical solution supply pipe 53 so as not to be interrupted, and returns the excess chemical liquid that has not been supplied to the chemical solution supply pipe 53 from the chemical solution return pipe 52.

  The minute flow rate adjusting mechanism 6 includes a drip flow meter 61 having an opening / closing valve 62 at the bottom, and a drip amount adjusting valve 60 disposed at the top of the drip flow meter 61. Adjusting the dropping amount adjusting valve 60 while measuring the amount of the chemical liquid dropped on the dropping flow meter with the opening / closing valve 62 closed, the target injection amount is adjusted, and then the opening / closing valve 62 is opened to obtain the necessary amount. It becomes possible to accurately inject the chemical solution.

The flow rate of the sewage flowing out of the mixing tank 10 is measured using a flow sensor, and the concentration of sodium hypochlorite is set to a predetermined concentration, for example, about 0.8 mg / cm ³ with respect to the sewage at the flow rate. Inject sodium hypochlorite.

  If the flow rate of sewage from the mixing tank 10 is close to the planned amount, adjust the pumping amount to an appropriate level by controlling the rotational speed of the pump 3 and adjusting the opening of the discharge valve 4 by the inverter control device 30. However, when the amount of water is much smaller than the planned amount of water, even if the number of revolutions of the pumping pump 3 is controlled by the inverter control device 30, it cannot be adjusted to an appropriate amount of pumped water. It becomes difficult to adjust the amount of pumped water.

  Even in such a case, as long as a higher amount of the chemical solution than the necessary injection amount is pumped by the pumping pump 3, the chemical solution supplied to the chemical solution supply pipe 53 by the chemical solution distributor 5 is appropriately adjusted by the minute flow rate adjusting mechanism 6. Since it is injected into the sewage after being adjusted to, the injection amount can be adjusted very accurately.

  At this time, since the excessive chemical liquid pumped by the pump 3 is returned from the chemical liquid return pipe 52 to the chemical liquid tank 2, the chemical liquid is not wasted and the chemical liquid can be consumed efficiently. In addition, since the chemical liquid is naturally dropped and returned to the chemical liquid tank 2, it is economical because it does not require additional transport energy.

  The specific configuration of the minute flow rate adjusting mechanism 6 is not particularly limited, and a dropping amount adjustment that is a dropping flow meter 61 provided with an on-off valve 62 at the bottom and a throttle valve disposed on the upper portion of the dropping flow meter 61. The aspect with which the valve 60 is comprised integrally may be sufficient.

  Further, as shown in FIG. 2, the minute flow rate adjusting mechanism 6 may be configured only by the dropping amount adjusting valve 60 which is a throttle valve. In this case, it is necessary that the amount of dripping be adjusted almost accurately by adjusting the amount of throttling according to the scale indicated on the throttle valve. Furthermore, you may control to a fixed rotational speed, without providing the inverter control apparatus which variably controls the rotational speed of the pumping pump 2 which pumps a chemical | medical solution to the chemical | medical solution inflow pipe 51. FIG.

  As shown in FIG. 3, the branch pipe 11 that connects the chemical liquid pumped to the chemical liquid inflow pipe 51 by the pumping pump 3 to the chemical liquid injection unit 7 without going through the chemical liquid distribution mechanism 50, and the chemical liquid to the chemical liquid distribution mechanism It is preferable to include switching valves 12 and 13 for switching whether the liquid is pumped to 50 or the branch pipe 11 is pumped.

  By operating the switching valves 12 and 13, it is possible to switch whether the chemical liquid pumped to the chemical liquid inflow pipe 51 by the pumping pump 2 is pumped to the chemical liquid distribution mechanism 50 or pumped to the branch pipe 11. become. When it is necessary to properly inject a small amount of chemical into the injection target, the switching valves 12 and 13 are switched so as to pump up the chemical distribution mechanism 50, for example, a sufficient amount of the injection target to substantially match the planned water volume. When the chemical solution is injected into the pump, the pumping amount can be appropriately adjusted by adjusting the rotational speed of the pumping pump 2 and the like, and the switching valves 12 and 13 may be switched so as to pump the liquid into the branch pipe 11.

  That is, according to the method of operating the chemical injection system according to the present invention, when the flow rate of the chemical injection target liquid is lower than the predetermined flow rate, the switching valves 12 and 13 are switched so that the chemical solution is pumped to the chemical distribution mechanism 50 to adjust the micro flow rate. The mechanism 6 adjusts the injection amount of the chemical solution, and when the flow rate of the chemical solution injection target liquid is higher than the predetermined flow rate, the switching valves 12 and 13 are switched so that the chemical solution is pumped to the branch pipe 11, and the pump 3 is rotated. The injection amount of the chemical liquid is adjusted by adjusting the number or adjusting the opening of the discharge valve 4.

  Since the flow rate of the sewage flowing out from the mixing tank 10 varies, it may be configured to measure using a flow rate sensor at predetermined time intervals and manually adjust the rotational speed of the pumping pump 2 and the minute flow rate adjusting mechanism 6 each time. Good.

  Moreover, you may provide the dripping amount control apparatus which adjusts the dripping amount by the dripping flowmeter 61 automatically based on the flow volume of the sewage measured using the flow sensor. For example, a drop amount calculating device that includes an image pickup device that takes an image of the drop flow meter 61 and that performs image processing on a photographed image by the image pickup device, and an opening degree of the drop amount adjusting valve 60 An opening adjustment mechanism with a motor for adjusting the flow rate, and a flow rate input unit, calculate an appropriate chemical solution injection amount according to the input flow rate of sewage, and a dripping amount calculation device so that the calculated chemical solution injection amount is obtained The drop amount control apparatus adjusts the opening degree of the drop amount adjustment valve 60 while feeding back the drop amount calculated by the above.

  In the above-described embodiment, the example in which the chemical solution distribution pipe 55 is connected to the pipe end of the chemical solution inflow pipe 51 and the distribution flow rate adjustment valve 56 is provided has been described. The distribution flow rate adjusting valve 56 is not necessarily provided as long as the supply flow rate adjustment valve 56 is configured to be sufficiently supplied to the power supply 53.

  Further, as shown in FIG. 4A, a guide pipe 58 for dropping the pumped chemical liquid from above the chemical liquid supply pipe 53 is provided instead of the chemical liquid distribution pipe 55 provided at the pipe end of the chemical liquid inflow pipe 51. You may have.

  As shown in FIG. 4B, the chemical solution distribution mechanism 50 includes a chemical solution tank 54 through which a chemical solution supply pipe 53 and a chemical solution return pipe 52 are inserted at the bottom and receives the chemical solution overflowing from the chemical solution supply pipe 53. The opening end of the tube 53 may be disposed higher than the opening end of the chemical liquid return tube 52.

  According to the above-described configuration, the chemical liquid pumped from the chemical liquid inflow pipe 51 is supplied to the chemical liquid supply pipe 53 so as not to be interrupted. At this time, the chemical liquid overflowing from the chemical liquid supply pipe 53 is stored in the chemical liquid tank 54 and flows into the chemical liquid tank by flowing in from the opening end of the chemical liquid return pipe 52 disposed lower than the opening end of the chemical liquid supply pipe 53. Since the fallen liquid is returned, even when the supply amount of the chemical solution from the chemical solution inflow pipe 51 is much larger than the required amount, the chemical solution tank ensures that the excess chemical solution is injected while the chemical solution is injected into the injection target with an appropriate injection amount. Can be returned to.

  The chemical tank 54 is preferably provided with a lid 59 that can be freely opened and closed, so that the inside of the chemical tank 54 can be appropriately maintained. From such a viewpoint, it is preferable that the chemical liquid inflow pipe, the chemical liquid return pipe, and the chemical liquid supply pipe are attached to the side wall or bottom of the chemical liquid tank 54.

  Hereinafter, other embodiments of the present invention will be described. In the above-described embodiment, the chemical solution injection system for injecting the bactericide into the mixing pond provided in the water treatment system for sewage has been described. However, the place where the chemical solution injection system is built is not limited to the mixing pond, and the water purification pond of the water supply facility A chemical solution injection system may be constructed in a water reservoir, etc., and a chemical solution injection system is constructed at predetermined intervals along the distribution pipe, and the chemical solution is injected into the water supplied to the distribution pipe. Is also possible. This is for avoiding that it is difficult to maintain the sanitary state due to a decrease in the concentration of the chemical solution over time due to long-distance water supply.

  In the above-described embodiment, the case where the disinfectant is injected as the chemical solution has been described. However, the chemical solution used in the chemical solution injection system is not limited to the disinfectant, and other types of chemical solutions may be used. For example, a flocculant used to concentrate and dewater sludge generated after biological treatment in a sewage treatment facility, or a flocculant used in a chemical mixing pond of a water supply system to remove suspended matter from the raw water taken, such as polychlorinated The chemical injection system according to the present invention can be used when injecting an iron-based flocculant such as ferric iron or an aluminum-based flocculant such as polyaluminum chloride.

  Furthermore, the chemical solution injection system according to the present invention can be applied to a water treatment facility for treating leachate constructed in a final disposal site for organic waste. The amount of leachate is small at the initial stage of landfill, and it is also effective to inject an appropriate amount of chemical solution necessary for biological treatment of such a small amount of leachate. For example, the present invention can be applied to injection of methanol as a BOD source necessary for biological treatment, injection of an oxidizing agent necessary for decomposition of a hardly decomposable organic substance, injection of a calcium removal agent, injection of a disinfectant, and the like.

  Further, as shown in FIG. 5, the chemical liquid tank 2, the chemical liquid inflow pipe 51 connected to the chemical liquid tank 2 through the chemical liquid pump 3, and the chemical liquid supplied from the chemical liquid inflow pipe 51 are connected to the chemical liquid injection unit 10. The medicinal solution distribution mechanism 50 that distributes the medicinal solution supply pipe 53 and the medicinal solution return pipe 52 that returns to the medicinal solution tank 2, and the medicinal solution injecting unit 10 without supplying the medicinal solution supplied to the medicinal solution inflow pipe 51 without going through the medicinal solution distribution mechanism 50. The chemical injection system may be configured to include the branch pipe 11 connected to the switching pipes 12 and 13 for switching whether the chemical liquid is supplied to the chemical distribution mechanism 50 or the branch pipe 11.

  The chemical solution distribution mechanism 50 includes a chemical solution distribution pipe 55, a distribution flow rate adjustment valve 56, and a flow rate measurement mechanism, and a small amount of chemical solution injection injected from the chemical solution supply pipe 53 to the chemical solution injection unit 10 by the distribution flow rate adjustment valve 56. The amount is adjusted based on the measurement result by the flow rate measuring mechanism, and the surplus chemical liquid is returned from the chemical liquid return pipe 52 to the chemical liquid tank 2. The flow rate measuring mechanism is preferably built in the distribution flow rate adjusting valve 56.

  For such a chemical solution injection system, when the flow rate of the chemical solution injection target liquid is smaller than a predetermined flow rate, the switching valves 12 and 13 are switched so that the chemical solution is supplied to the chemical solution distribution mechanism 50, thereby reducing the injection amount of the chemical solution. And the switching valves 12 and 13 are switched so that the chemical solution is supplied to the branch pipe 11 when the flow rate of the chemical solution injection target liquid is higher than the predetermined flow rate, and the chemical solution pump 3 adjusts the injection amount of the chemical solution. do it.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description, and the specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. Needless to say.

1: Chemical liquid injection system 2: Chemical liquid tank 3: Liquid pump 4: Discharge valve 5: Chemical liquid distributor 6: Micro flow rate adjusting mechanism 7: Chemical liquid injection part 50: Chemical liquid distribution mechanism 51: Chemical liquid inflow pipe 52: Chemical liquid return pipe 53 : Chemical liquid supply pipe 54: Chemical liquid tank 57: Ventilation pipe

Claims (11)

And the chemical inlet pipe connected to a liquid tank and chemical solution return pipe, and the chemical supply pipe connected to the drug fluid injecting section for injecting a liquid medicine into chemical liquid injector target liquid treated in each type of water treatment plant, the chemical supply pipe The chemical solution is supplied from the chemical solution inflow pipe to the opening of the chemical solution supply pipe so that the chemical solution is supplied to the chemical solution supply pipe without interruption. And a chemical distribution mechanism for returning the excess chemical liquid that has not been supplied to the chemical liquid supply pipe from the chemical liquid return pipe ,
The medicinal solution distribution mechanism includes a medicinal solution dispensing apparatus including a medicinal solution tank that is connected to the medicinal solution inflow pipe, the medicinal solution return pipe, and the medicinal solution supply pipe, stores the medicinal solution overflowing from the opening, and supplies the medicinal solution return pipe .   The chemical solution distribution apparatus according to claim 1, further comprising a minute flow rate adjusting mechanism that adjusts the amount of the chemical solution injected from the chemical solution injection section between the chemical solution supply pipe and the chemical solution injection section.   The medicinal liquid distribution mechanism distributes a predetermined amount of medicinal liquid fed from the medicinal liquid inflow pipe to the medicinal liquid supply pipe and also distributes a medicinal liquid distribution pipe provided with a distribution flow rate adjusting valve for distributing excess medicinal liquid to the medicinal liquid return pipe. The chemical | medical solution distribution apparatus of Claim 1 or 2 provided. Wherein the bottom of the chemical tank chemical liquid supply pipe and the chemical return pipe is inserted, before Symbol chemical supply pipe according to claim 3, wherein arranged in the lower well opening end than the opening end portion of the chemical return tube Chemical dispensing device. Wherein the bottom of the chemical tank chemical liquid supply pipe and the chemical return pipe is inserted, before Symbol chemical opening end of the supply pipe is the chemical return pipe according to claim 1 or are arranged so high than the open end of the 2. The chemical solution distributor according to 2.   The chemical solution distribution device according to claim 4 or 5, wherein the chemical solution tank includes a vent pipe for releasing a gas generated inside to the atmosphere. A chemical tank,
A chemical inlet pipe and chemical return pipe connected to the chemical liquid tank, a chemical supply pipe connected to the drug fluid injecting section for injecting a liquid medicine into chemical liquid injector target liquid treated in each type of water treatment plant, the chemical supply More than the necessary supply amount to the tube, the chemical solution is fed from the chemical solution inflow tube and supplied toward the opening of the chemical solution supply tube, and the excess chemical solution not supplied to the chemical solution supply tube is supplied to the tube. A chemical distribution mechanism to return from the return tube;
Between the chemical liquid supply pipe and the chemical liquid injection part, a fine flow rate adjustment mechanism for adjusting the amount of chemical liquid injected from the chemical liquid injection part,
Equipped with a,
The chemical solution distribution mechanism is connected to the chemical solution inflow pipe, the chemical solution return pipe, and the chemical solution supply pipe, and stores a chemical solution overflowing from the opening and supplies a chemical solution tank that supplies the chemical solution return pipe to the chemical solution return pipe. .   The chemical liquid injection system according to claim 7, wherein the minute flow rate adjusting mechanism includes a drip flow meter having an opening / closing valve at a bottom portion and a drip amount adjusting valve arranged at an upper portion of the drip flow meter.   9. The chemical liquid injection system according to claim 7, further comprising a liquid feed pump capable of adjusting a liquid feed amount between the chemical liquid tank and the chemical liquid inflow pipe. A branch pipe for connecting the chemical liquid fed to the chemical liquid inflow pipe by the liquid feeding pump to the chemical liquid injection section without going through the chemical liquid distribution mechanism;
A switching valve for switching whether to send the chemical liquid to the chemical liquid distribution mechanism or to the branch pipe;
The chemical | medical solution injection system of Claim 9 provided with.   The operation method of the chemical injection system according to claim 10, wherein the switching valve is switched so that the chemical liquid is sent to the chemical distribution mechanism when the flow rate of the chemical injection target liquid is smaller than a predetermined flow rate, and the minute flow rate is changed. Adjusting the injection amount of the chemical solution with the adjustment mechanism, switching the switching valve so that the chemical solution is sent to the branch pipe when the flow rate of the chemical solution injection target liquid is higher than the predetermined flow rate, and injecting the chemical solution with the liquid feed pump How to operate the chemical injection system to adjust the volume.

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