JP6050766B2 - Sludge dewatering device and operation method thereof - Google Patents

Description

  The present invention relates to a sludge dewatering device that can exhibit the same dewatering performance as a conventional primary dewaterer while being low in cost, and an operation method thereof.

  Various dehydration technologies have been developed for primary dehydrators, such as centrifugal separation, press (filter press, screw press, belt press, etc.), and vacuum, but the water content of dewatered sludge is 80-85%. The degree is the limit.

  If the moisture content of the dewatered sludge is about 80 to 85%, composting this will result in anaerobic generation inside the compost layer due to excessive water content even if it is turned over, and a fully-ripened compost cannot be produced. For this reason, in order to adjust the moisture to about 60%, sawdust and the like are mixed and used as a moisture adjusting material. However, the use of these moisture adjusting materials is not preferable because it increases costs.

  Patent Document 1 discloses a method of dehydrating organic sludge using an electroosmotic dehydrator (EDP), and the electroosmotic dehydrator (EDP) provides a moisture content of 64% (see Table 1 of Patent Document 1). It is disclosed that can be realized. If the moisture content is 64%, the cost can be reduced in composting.

  Moreover, since the water content is low according to electroosmotic dehydration, the use of resources as a combustion aid is being studied.

  When such an electroosmotic dehydrator (EDP) is used as a secondary dehydrator, a two-stage dehydrator is used, which increases the initial cost.

Japanese Patent Publication No.8-9514 JP 2003-2111293 A

  Then, this inventor examined using the solid-liquid separation apparatus (patent document 2) with a track record as a concentrator, without using a pressure-type primary dehydrator as a primary dehydrator.

  As a result, the present inventors have found that by partially improving the apparatus and discovering the dehydrating operation method, the dehydrating performance similar to that of the conventional primary dehydrator can be exhibited at a low cost.

  That is, an object of the present invention is to provide a sludge dewatering apparatus that can exhibit the same dewatering performance as a conventional primary dehydrator and an operation method thereof while being low in cost.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

1. The sludge dewatering device has a sludge inlet at one end and a dewatered sludge discharge at the other end.
Inside the sludge dewatering device main body, there is a space conveyance path for conveying the sludge introduced from the sludge input part toward the discharge part while dehydrating,
Above the space conveyance path, a movable inclined plate that forms a pressing state between sludges moving in the space conveyance path,
Below the space transport path, a plurality of rotation shafts are arranged in parallel across the width direction of the space transport path,
Each rotating shaft is mounted with a plurality of rotating plates each formed in an oval shape, and the phases of the plurality of rotating plates provided on the adjacent rotating shafts are shifted by 90 °, respectively.
Between the rotating plates, a plurality of guide members extending linearly from the sludge input part to the discharge part are arranged side by side to form a guide surface,
The guide surface has at least a gap between the adjacent guide members and a gap between adjacent rotary shafts, and the dehydrated filtrate is dropped from the gap. A method for operating a sludge dewatering device , characterized by
In the process of dewatering the sludge collected on the guide member while transporting it toward the discharge portion by the outer peripheral surface of the rotating plate, the guide plate is moved toward the discharge portion. By reducing the amount of protrusion from the upper end surface and decreasing the conveying force, the sludge gradually stagnates to form a sludge retention part,
Decreasing the conveying force by causing the sludge on the upper surface of the staying part to collide with the lower surface of the inclined plate arranged in an inclined manner and press-contacting it,
In the process in which the sludge at the lower part of the staying part is transported toward the discharge part by the rotation of the rotating plate, the sludge at the upper part of the staying part having reduced transport force is guided by the guide surface of the guide member due to the difference in transport speed. As a result, an arc-shaped sludge surface is formed on the rear end surface of the staying part,
A method for operating a sludge dewatering apparatus, wherein a dewatering operation is performed by compressing or squeezing the staying part in a process of moving the sludge on the upper part of the staying part toward the guide surface of the guide member.

  According to the present invention, it is possible to provide a sludge dewatering device that can exhibit the same dewatering performance as a conventional primary dewaterer and an operation method thereof at low cost.

  When the sludge dewatering device of the present invention is used as the primary dewatering device of the electroosmotic dewatering device, the initial cost can be reduced with a simple structure, few peripheral devices, low power, easy maintenance and running cost. Can be reduced. In addition, safety is high due to low speed and low pressure.

  Furthermore, since it is not pressure-type dehydration such as a conventional filter press, there is an effect that the adjustment of the drug is easier than before in the aggregating process with the drug as a pretreatment to be put into the primary dehydrator. In pressure-type dewatering, depending on the state of sludge flocculation, dewatering may not be possible, so it was necessary to determine the state of sludge that changes from time to time and to adjust the coagulant. According to the present invention, it can be dehydrated to about 85% even in a somewhat loose state, and there is no need to finely adjust the drug depending on the state of sludge.

The figure which shows an example of the sludge dehydration process using the dehydration apparatus of this invention Sectional drawing which shows roughly an example of sludge dehydration equipment Sectional view of the sludge transport path seen from the direction along the transport direction Sectional drawing which shows schematically an example of the process in which sludge is conveyed using the sludge dehydration apparatus which concerns on this invention The graph which compared the moisture content of the dewatered sludge in each driving | running condition at the time of using the sludge dewatering apparatus which concerns on this invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an example of a sludge dewatering system using a sludge dewatering apparatus according to the present invention.

  In the present invention, the sludge to be dewatered by the sludge dewatering apparatus is not particularly limited, but for example, surplus sludge generated in biological treatment such as sewage treatment and human waste treatment, pretreatment sludge for biological treatment, anaerobic treatment Examples include digested sludge after fermentation.

  Biological treatment apparatuses such as sewage treatment and human waste treatment basically comprise an aeration tank (reaction tank) and solid-liquid separation means (such as a precipitation tank and a membrane apparatus). In the aeration tank (reaction tank), decomposition of organic substances and nitrification of ammonia by microorganisms in the tank (usually referred to as activated sludge) are performed. In the solid-liquid separation means, activated sludge and treated water are separated. Most of the separated activated sludge is returned to the aeration tank (reaction tank), and a part is taken out of the reaction system as excess sludge and dehydrated. When the organic matter contained in the wastewater is treated, the organic matter is converted into sludge according to the treatment. Usually, about 15 to 30% (weight) of the organic matter amount is regarded as the sludge conversion rate. If the generated sludge according to the sludge conversion rate is removed from the system, the biological treatment in the aeration tank (reaction tank) proceeds smoothly. The generated sludge according to this sludge conversion rate is called surplus sludge.

  Wastewater such as sewage and human waste often contains organic solids. If these solids are sent directly to the aeration tank (reaction tank), the load of organic substances becomes excessive. Usually, as a pretreatment, a primary precipitation tank or membrane treatment is provided, and solid-liquid separation is performed. Things are being removed. These separated solids are also commonly referred to as sludge and are subject to dehydration. This is because it is necessary to remove moisture even if it is composted or incinerated.

  In the following description, the case where the sludge to be dehydrated is excess sludge will be described.

  Excess sludge is extracted from the settling tank and transferred to the concentration tank. In the concentration tank, the concentration of excess sludge is concentrated to obtain concentrated sludge. This is to reduce the load on the sludge dehydrator by reducing the water concentration.

  In the figure, 1 is a sludge dewatering device, 2 is a sludge tank, 3 is a coagulation tank, and 4 is a polymer coagulant tank for storing a polymer coagulant.

  The concentrated sludge is supplied to the sludge tank 2. Thereafter, the water is supplied to the aggregation tank 3 by the pump 201. In the flocculation tank 3, the polymer flocculant is supplied from the polymer flocculant tank 4 by the pump 401 to the supplied concentrated sludge. This is for efficient dehydration. A stirrer 302 is installed in the coagulation tank, and the concentrated sludge and the polymer coagulant are mixed and stirred.

  The polymer flocculant tank 4 is provided with a stirrer (not shown), and the concentration of the flocculant is adjusted as necessary.

  Aggregated concentrated sludge is transferred to a sludge dewatering device by a pump 301 and dehydrated.

  Although the amount of sludge filtrate is small, the one with high SS concentration may be returned to the sludge tank 2 and re-dehydrated.

  The sludge dewatering device will be described in detail below.

  FIG. 2 is a cross-sectional view schematically showing an example of a sludge dewatering device, and FIG. 3 is a cross-sectional view of a sludge transport path as viewed from the direction along the transport direction.

  The sludge dewatering device 1 has an input portion 10a into which sludge is charged at the upper end of one end (left end in FIG. 2) of a sludge dewatering device main body (casing) 10 whose upper side is open, and the other end (see FIG. 2 has a discharge part 10b for discharging the dewatered sludge after the dehydration treatment to the outside of the apparatus. In the casing 10, there is a conveyance path 11 for dewatering the sludge introduced from the input unit 10 a toward the discharge unit 10 b.

  A rotation shaft 12 is spanned across the transport path 11 across the width direction of the transport path 11 (the left-right direction in FIG. 3). A plurality of rotation shafts 12 are provided at substantially equal intervals (preferably at equal intervals) in the left-right direction in FIG.

  Each rotary shaft 12 is mounted with a plurality of elliptical rotary plates 13 at regular intervals. The rotary plates 13 of the same rotary shaft 12 are mounted so as to have the same phase, but the phase of the rotary plate 13 is shifted by 90 ° between the adjacent rotary shafts 12.

  It is preferable that the size (diameter) of the rotating plate 13 is gradually reduced from the sludge input part toward the discharge part.

  The rotating plate 13 can be formed of, for example, a resin plate, a stainless plate, a ceramic plate, or the like. The plate | board thickness of the rotating plate 13 can be 0.3-1.0 mm, for example.

  On each rotary shaft 12, a thin plate-like guide member 14 extending linearly from the input portion 10 a to the discharge portion 10 b so as to be orthogonal to the rotary shaft 12 is provided on each rotary plate 13 of each rotary shaft 12. A plurality are arranged so as to be inserted therebetween.

  The guide member 14 can be formed of, for example, an iron steel plate, a stainless steel plate, or a resin plate. The thickness of the guide member 14 (thickness along the axial direction of the rotating shaft 12) is equal to or less than the interval between the adjacent rotating plates 13 on the rotating shaft 12, but specifically, for example, 0.7 to 1.5 mm. It can be.

  The upper end surface of the guide member 14 forms a smooth guide surface that guides the conveyance of sludge toward the discharge portion 10b by arranging a plurality of guide members 14 side by side. This guide surface is formed in a slit shape by arranging a plurality of guide members 14 side by side, and a gap S1 (see FIG. 3) between the adjacent guide members 14 and the rotary plates of the adjacent rotary shafts 12 are mutually connected. The filtrate (dehydrated filtrate) dehydrated from the sludge is dropped by the gap S2 between 13 (see FIG. 2).

  Both ends of each rotary shaft 12 are pivotally supported through the side wall 10c of the casing 10, and pulleys 12a are respectively attached to one end thereof. Adjacent pulleys 12a are configured to transmit a driving force of a motor (not shown) by winding a timing belt (not shown). By rotating the motor, the rotary shafts 12 are simultaneously rotated at the same speed in the same direction (clockwise in FIG. 1) to rotate the rotary plates 13.

  It is preferable to decelerate the motor so that each rotating plate 13 can be rotated slowly, for example, at about 10 to 50 rpm.

  Since the phase of the rotating plate 13 is shifted by 90 ° between the adjacent rotating shafts 12, the longer diameter side of the rotating plate 13 protrudes above the upper end surface of the guiding member 14 from the gap S 1 between the adjacent guiding members 14. Thereby, the outer peripheral surface (feeding surface) of the rotating plate 13 as a whole operates so as to form a wave from the input portion 10a toward the discharge portion 10b, and the scraping force and the conveyance with respect to the sludge on the guide member 14 Force is applied. In addition, since the rotating plate 13 is elliptical, it can be scraped and transported twice per rotation, and therefore has a large transport capability.

  As long as the size (diameter) of the rotating plate 13 is gradually reduced from the sludge inlet to the outlet, the mounting positions of the rotary shafts 12 may all be the same height. The amount of protrusion of each rotary plate 13 above the upper end surface of the guide member 14 can be gradually reduced as it approaches the discharge portion 10b.

  In addition, when all the rotary plates 13 are the same size, the mounting position of each rotary shaft 12 may be varied. In the present invention, the rotary plate 13 is gradually lowered from the input portion 10a side to the discharge portion 10b side. It is preferable. Since the mounting position of the rotary shaft 12 gradually decreases as it goes to the discharge portion 10b, the amount of protrusion of each rotary plate 13 above the upper end surface of the guide member 14 can be gradually reduced as it approaches the discharge portion 10b. it can.

  Since the protruding amount of the rotating plate 13 gradually decreases as going to the discharge unit 10b, the scraping force and the conveying force against the sludge gradually decrease.

  The rotating plate 13 located on the discharge unit 10b side has the smallest protrusion amount or no protrusion at all, so that only a little scraping force and conveying force are applied to the sludge, or the scraping force and A structure that hardly causes the conveying force to act is formed.

  The rotating plate 13 positioned on the input portion 10a side protrudes greatly from above the guide member 14, and has a structure in which a large scraping force and conveying force are applied to the sludge.

  A filtrate take-out part 10 d for taking out the dehydrated filtrate dropped from the transfer path 11 is formed below the transfer path 11. The filtrate take-out portion 10 d is formed on the lower surface of the casing 10.

  A first filtrate receiving tank 15a and a second filtrate receiving tank 15b are arranged below the filtrate take-out portion 10d.

  The first filtrate receiving tank 15a has a size that covers the entire length of the transport path 11, and is relatively SS that is filtered from sludge transported in the first half of the transport path 11 near the input portion 10a. It accepts dehydrated filtrate with low concentration. Further, the second filtrate receiving tank 15b is adapted to receive a dehydrated filtrate having a relatively high SS concentration filtered from sludge transported in the latter half of the transport path 11.

  The dehydrated filtrate stored in the first filtrate receiving tank 15a and the second filtrate receiving tank 15b is taken out of the tank by a drain pipe (not shown).

  Above the transport path 11 in the casing 10, an inclined plate 16 is disposed so as to be inclined downward as the ceiling of the transport path 11 goes to the discharge unit 10 b. The inclined plate 16 functions to accelerate dewatering by gradually squeezing the dewatered sludge transported on the transport path 11 from top to bottom.

  The inclined plate 16 has a width extending in the width direction of the transport path 11 and has a length extending from the vicinity of the input portion 10a to the discharge portion 10b, leaving a space serving as the input portion 10a. One end of the inclined plate 16 on the input portion 10a side is pivotally supported on the side wall 10c of the casing 10, and the other end side is disposed so as to incline downward toward the discharge portion 10b. The discharge portion 10 b is formed between the lower surface on the other end side of the inclined plate 16 and the upper end surface of the guide member 14.

  A hydraulic cylinder 17 is attached to the upper surface of the inclined plate 16 near the discharge portion 10b. The inclination angle of the inclined plate 16 is adjusted by the hydraulic cylinder 17 in accordance with the properties of sludge and the required dehydration degree, and the adjusted inclination angle is maintained. The height (exit thickness) h of the discharge portion 10b shown in FIG.

  Also, in place of the hydraulic cylinder, a known one is used as long as a load can be applied so as to maintain an inclination angle according to the properties of sludge and the required degree of dehydration, such as an air cylinder, a mechanical spring, and a weight. be able to.

  Next, an operation method of the sludge dewatering device 1 will be described.

  When all the rotating plates 13 are rotated at a predetermined speed and the sludge is introduced from the charging portion 10a, the sludge is gradually discharged along the upper end surface of the guide member 14 while being scraped from below by the outer peripheral surface of the rotating rotating plate 13. It conveys toward the part 10b.

  In the process of conveying the sludge, the filtrate (dehydrated filtrate) falls from the gap S1 between the guide members 14 and the gap S2 between the rotating plates 13, and is discharged from the filtrate take-out portion 10d to the filtrate receiving tank 15a or 15b. Is done.

  The sludge (dehydrated sludge) collected on the guide member 14 is further dehydrated while being conveyed toward the discharge portion 10b by the outer peripheral surface of the rotating plate 13 that rotates one after another.

  As the rotating plate 13 approaches the discharge part 10b, the amount of protrusion from the upper end surface of the guide member 14 decreases and the conveying force decreases. Therefore, as shown in FIG. The stay part G is formed.

  This staying part G is pushed by the sludge newly transported as the rotating plate 13 rotates, and gradually moves toward the discharge part 10b. In this process, the upper surface of the staying part G is Then, it collides with the lower surface of the inclined plate 16 disposed in an inclined manner and is pressed.

  Since the conveying force due to the rotation of the rotating plate 13 substantially acts on the lower part of the staying part G, the lower part of the staying part G gradually moves toward the discharge part 10b. The conveyance force hardly acts only by contacting with 16. For this reason, when the sludge below the staying part G is moving, the downward sludge moves from the inclined plate 16 toward the guide member 14, as indicated by arrows in FIG. The downward sludge movement from the inclined plate 16 toward the guide member 14 compresses (squeezes) the stay portion G, and further promotes dehydration.

  The rear end face Ga of the staying part G has the slant plate 16 and the guide member 14 due to the sludge that moves downward from the slant plate 16 and the deviation of the transport speed of sludge that is transported toward the discharge part 10b by the rotation of the rotary plate 13. An arc-shaped sludge surface is formed between the two. If dehydration operation is performed so that this sludge surface is formed, dehydrated sludge having a suitable moisture content can be obtained.

  Examples of the present invention will be described. The present invention is not limited to the embodiments.

Example 1
Sludge was dehydrated using a sludge dewatering system similar to that shown in FIG.

  The following test data in the present invention was performed using concentrated sludge transferred from an existing facility.

  The concentrated sludge transferred from the existing system to the sludge tank 2 was mixed with 42 L / Hr of the high concentration filtrate in the latter half of the sludge dewatering apparatus 1 having an SS concentration of 28,000 mg / L and transferred to the flocculation tank 3. The feed concentrated sludge had an SS concentration of 10,000 mg / L and a flow rate of 800 L / Hr.

  In the flocculation tank 3, 1.65 ml / min of a polymer flocculant having a concentration of 0.2% was added to the supplied concentrated sludge from the polymer flocculant tank and stirred. As the flocculant, MM floc manufactured by Hymo Co., Ltd. was used, and the condensed concentrated sludge supplied was supplied to the sludge dewatering apparatus 1 at 15 L / min to dehydrate the concentrated sludge.

As a sludge dewatering device, an improved machine of a slit saver dewatering type (SS311) manufactured by Kenden Corporation was used with the following settings.
-Width from the side wall 10c of the casing 10 to the other side wall 10c: 300 mm
・ Gap S1 between guide members 14: 0.7 mm
-Number of rows of 13 rotating plates: 9 stages-Sludge dewatering device 1 Dimensions: 930L x 570W x 255H

  The mounting positions of the respective rotary shafts 12 are arranged so as to be gradually lowered from the input portion 10a side to the discharge portion 10b side, and are installed so as not to protrude at all on the rotary plate 13 positioned on the discharge portion 10b side.

  The rotation speed of the rotating plate 13 of the sludge dewatering apparatus 1 was adjusted so that the dewatered sludge discharge speed was 30 mm / min.

  Moreover, the height dimension (outlet thickness) h of the discharge part 10b of the sludge dewatering apparatus 1 was set to 70 mm.

  In the process of conveying the sludge, the filtrate (dehydrated filtrate) falls from the gap S1 between the guide members 14 and the gap S2 between the rotating plates 13, and is discharged from the filtrate take-out portion 10d to the filtrate receiving tank 15a or 15b. Is done.

  The dehydrated filtrate that fell in the process of transporting sludge and was discharged into the filtrate receiving tank 15a had SS concentrations of 82 mg / L and 815 L / Hr. The dehydrated filtrate discharged to the filtrate receiving tank 15b had SS concentrations of 28,000 mg / L and 42 L / Hr. The dehydrated filtrate discharged to the filtrate receiving tank 15b was returned to the sludge tank 2.

  When the concentrated sludge was dehydrated under the above conditions, the water content of the dehydrated sludge after dehydration was 81.2%.

  When the concentrated sludge is dewatered in the sludge dewatering apparatus 1, as shown in FIG. 4, the sludge gradually stagnates to form a sludge retaining portion G, and an arc-shaped sludge surface is formed on the rear end surface Ga of the retaining portion G. It was confirmed that the sludge was transported in the state of forming the water and being dehydrated.

(Examples 2 to 12)
Using a sludge dewatering device having the same configuration as that used in Example 1, the test was performed under the test conditions in which the sludge input amount, the discharge speed, the outlet thickness h, and the chemical injection amount were changed to the values shown in Table 1, Its water content was evaluated.

At this time, during the concentration sludge dewatering in the sludge dewatering apparatus 1, as shown in FIG. 4, the sludge was transported in a state in which the sludge gradually stagnates and forms a sludge retaining portion G.
The results are shown in Table 1 and FIG.

  On the other hand, adjusting the discharge rate of dewatered sludge and the outlet thickness of the sludge discharge part of the sludge dewatering device 1 confirmed that the sludge was not dehydrated when it was transported without forming the convection part G of sludge. did it.

<SS recovery rate>
(Examples 13 and 14)
Using a sludge dewatering apparatus having the same configuration as that used in Example 1, tests were conducted under the test conditions shown in Table 2, and the rate of change in the drainage SS concentration with respect to the sludge discharge rate was evaluated. At the time of concentrated sludge dewatering in the sludge dewatering apparatus 1, as shown in FIG. 4, the sludge was gradually stagnated and the sludge was transported in a state where a sludge retention part G was formed. The results are shown in Table 2.

  According to this test, it was proved that, when the primary dehydrator was used as a sludge dewatering device instead of the pressure type, the concentrated sludge could be dewatered to a moisture content of 87% or less.

  For this purpose, the mounting positions of the rotary shafts 12 of the sludge dewatering device are arranged so as to gradually decrease from the input portion 10a side to the discharge portion 10b side so that the amount of protrusion from the upper end surface of the guide member is reduced. It was confirmed that it was an important condition to perform the dehydration operation in a state where the sludge was gradually stagnated and the sludge staying portion G was formed.

  In addition, when the dewatering operation is performed in a state in which an arc-shaped sludge surface is formed on the rear end face Ga of the staying part G, it can be confirmed that the dehydration is particularly efficiently performed and the water content can be dehydrated to about 80 to 82%. It was.

  Moreover, according to an Example, it is preferable to adjust so that sludge input amount may be 20 L / min or less, More preferably, it can be considered as 13-16 L / min.

  Furthermore, it was confirmed that the SS recovery rate tends to deteriorate as the sludge discharge rate increases.

  Furthermore, depending on the state of the concentrated sludge, it was confirmed that the moisture content was not affected even if the flocculant was not adjusted, and there was no difference in the SS concentration discharged during the slit saver operation.

In the following, the effect of dehydration will be considered.
From the water content of dehydrated sludge when the discharge port thickness h described in the examples is changed, it can be seen that the discharge port thickness has little influence on the water content. Then, it is thought that dewatering of sludge is dehydrated by pressures other than the pressure from the upward direction by an inclined plate.

  This is because the sludge dewatering device rotating plate is arranged to gradually reduce the area protruding from the guide member as it goes to the dewatering sludge discharging port, so that the sludge is transported by the rotation of the rotating plate near the sludge discharging port. It is thought that it is due to being transported by pressing from the sludge loading direction.

  In this case, the upper surface of the stay part G collides with the lower surface of the inclined plate 16 and is pressed. Since the conveying force due to the rotation of the rotating plate 13 substantially acts on the lower part of the staying part G, the lower part of the staying part G gradually moves toward the discharge part 10b. The conveyance force hardly acts only by contacting with 16. For this reason, when the sludge below the staying part G is moving, the downward sludge moves from the inclined plate 16 toward the guide member 14, as indicated by arrows in FIG. It is considered that the stay part G is compressed (squeezed) by the downward sludge movement from the inclined plate 16 toward the guide member 14, and dehydration is promoted.

  The rear end face Ga of the staying part G has the slant plate 16 and the guide member 14 due to the sludge that moves downward from the slant plate 16 and the deviation of the transport speed of sludge that is transported toward the discharge part 10b by the rotation of the rotary plate 13. An arc-shaped sludge surface is formed between the two and the dehydration is considered to be further promoted when this state can be confirmed.

  It is considered that the concentrated sludge having a water content of about 98% can be dehydrated to a water content of 87% or less when using the sludge dewatering apparatus according to the present invention under the above-described conditions.

DESCRIPTION OF SYMBOLS 1: Sludge dewatering apparatus 10: Sludge dewatering apparatus main body, casing 10a: Input part 10b: Discharge part 10c: Side wall 10d: Filtrate extraction part 11: Spatial conveyance path, conveyance path 12: Rotating shaft 13: Rotating plate 14: Guide member 15a: first filtrate receiving tank 15b: second filtrate receiving tank 16: inclined plate 17: hydraulic cylinder 2: sludge tank 3: flocculation tank 4: polymer flocculant tank

Claims (1)

The sludge dewatering device has a sludge inlet at one end and a dewatered sludge discharge at the other end.
Inside the sludge dewatering device main body, there is a space conveyance path for conveying the sludge introduced from the sludge input part toward the discharge part while dehydrating,
Above the space conveyance path, a movable inclined plate that forms a pressing state between sludges moving in the space conveyance path,
Below the space transport path, a plurality of rotation shafts are arranged in parallel across the width direction of the space transport path,
Each rotating shaft is mounted with a plurality of rotating plates each formed in an oval shape, and the phases of the plurality of rotating plates provided on the adjacent rotating shafts are shifted by 90 °, respectively.
Between the rotating plates, a plurality of guide members extending linearly from the sludge input part to the discharge part are arranged side by side to form a guide surface,
The guide surface has at least a gap between the adjacent guide members and a gap between adjacent rotary shafts, and the dehydrated filtrate is dropped from the gap. A method for operating a sludge dewatering device , characterized by
In the process of dewatering the sludge collected on the guide member while transporting it toward the discharge portion by the outer peripheral surface of the rotating plate, the guide plate is moved toward the discharge portion. By reducing the amount of protrusion from the upper end surface and decreasing the conveying force, the sludge gradually stagnates to form a sludge retention part,
Decreasing the conveying force by causing the sludge on the upper surface of the staying part to collide with the lower surface of the inclined plate arranged in an inclined manner and press-contacting it,
In the process in which the sludge at the lower part of the staying part is transported toward the discharge part by the rotation of the rotating plate, the sludge at the upper part of the staying part with reduced transport force is guided by the guide surface of the guide member due to the difference in transport speed As a result, an arc-shaped sludge surface is formed on the rear end surface of the staying part,
A method for operating a sludge dewatering apparatus, wherein a dewatering operation is performed by compressing or squeezing the staying part in a process of moving the sludge on the upper part of the staying part toward the guide surface of the guide member.

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