JP2008221112A - Coagulation mixing tank and sludge dehydration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coagulation mixing tank which is capable of uniformly supplying a plurality of sludge dehydration means with coagulant-mixed sludge which keeps sludge mixed uniformly with coagulant. <P>SOLUTION: A horizontally placed tank body 31 is provided, and an agitating means 32 which consists of a rotary member 32a and an agitating element 32b protrusively provided in the outer circumference of the rotary member 32a is internally arranged in the longitudinal direction of the tank body 31. Also, a coagulation mixing tank 30 which has a sludge exit 31b for supplying coagulant-mixed sludge which consists of sludge and coagulant for a sludge dehydration means has a structure in which a plurality of sludge supplying openings 36a are arranged in a row at predetermined intervals in the longitudinal direction of one side face of the tank body 31, a plurality of coagulant supplying openings 37a are arranged in a row at predetermined intervals in a position outside of the rows of a plurality of sludge supplying openings 36a, and the sludge exits 31b are arranged in a row at predetermined intervals in the longitudinal direction of the upper part of the tank body 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flocculation mixing tank and a sludge dewatering device that make it possible to uniformly mix a flocculant with sludge.

  Sludge generated from a sewage treatment plant or the like is treated by being concentrated or dehydrated by a sludge concentrator or sludge dewatering device. Usually, a polymer flocculant (hereinafter referred to as flocculant) is added to the sludge and mixed (mixed), and the flocculant mixed sludge containing flocs aggregated by the flocculant mixed (mixed) is concentrated and dehydrated. Yes. Examples of the sludge dehydrator for concentrating and dewatering the coagulant mixed sludge include a rotary pressure dehydrator and a belt type sludge concentrator.

  The rotary pressure dehydrator includes a pair of disk-shaped filter plates that are rotated together with the inner ring spacer by a horizontal drive shaft that is driven by an electric motor with a speed reducer and that has a filtration surface. A dehydration chamber is formed between the pair of filter plates and an outer ring spacer in which the outer edges of the pair of filter plates are in sliding contact. In addition, the dewatering chamber is provided with a sludge supply unit for supplying coagulant mixed sludge conditioned by addition and mixing of the coagulant from a mixing tank provided outside the machine, and dehydrated cake is removed from the dewatering chamber. It has a dewatered cake discharger. The sludge supply part of the rotary pressure dehydrator according to this conventional example is located on the upper side of the rotation center of the disk-shaped filter plate and supplies the sludge from the outer peripheral part of the dehydration treatment chamber into the dehydration treatment chamber. Is provided. Further, the dewatering cake discharge section is provided at a position on the lower side from the rotation center of the disc-shaped filter plate and discharges the dewatering cake in the dehydration chamber from the outer periphery of the dewatering chamber (for example, Patent Documents 1 and 2 and Non-Patent Document 1).

And the sludge dehydration processing apparatus by which two rotation pressurization dehydration means of the above structures are arranged in parallel is disclosed by patent document 1, and four rotary pressurization dehydrators of the above structures are provided. Non-Patent Document 1 discloses a sludge dewatering treatment apparatus arranged in parallel. In the case of the plurality of rotary pressurizing and dehydrating means according to this conventional example, all are configured to be driven by one electric motor with a reduction gear.
JP-T-2004-532733 Japanese Patent Laid-Open No. 2004-90048 Rotary pressurization dehydrator, Japan Sewerage New Technology Promotion Organization, March 2002, p. 12-35

  The rotary pressure dehydrator according to the conventional examples described in Patent Documents 1 and 2 and Non-Patent Document 1 is compact and can easily arrange a plurality of rotary pressure dehydrators in parallel. In recent years, it has been used frequently because it has an excellent function of being easily manageable and easy to maintain. However, since the flocculant mixed sludge conditioned by the addition / mixing of the flocculant is supplied from the flocculent mixing tank to the rotary pressure dehydrator via the long sludge supply line, the following problems There is.

  That is, while the flocculant mixed sludge is being transferred through the sludge supply line, the flocs may be destroyed in the sludge supply line, and the dewatering performance may deteriorate. If the rotary dehydrator is provided with multiple dehydration chambers, the flow resistance of the sludge supply line communicating with the sludge supply section of each of the multiple dehydration chambers is set to be substantially the same. It is difficult to supply the same amount of sludge to each of the multiple dehydration chambers, and the sludge supply amount is excessive and the dewatering chamber cannot be sufficiently dehydrated, or the sludge is too small and the internal sludge is not pushed out. There is a possibility that a problem of extremely unstable operation such as sticking may occur.

  In addition, it is difficult to reduce the sludge dewatering cost because it is necessary to add about 1% flocculant per solid, for example, and the sludge dewatering device requires a large space for installation. There is also. In the case of a belt type sludge concentrator, conventionally, the coagulant mixed sludge conditioned by the addition and mixing of the coagulant is supplied from the coagulation mixing tank through a long sludge supply line. While flocculant mixed sludge is being transferred through the sludge supply line, there is a risk that flocs may be destroyed in this sludge supply line, causing problems such as dehydration performance deterioration, sludge supply tank sludge supply piping, etc. There is a problem that a large installation space is required to install the sludge treatment equipment.

  Accordingly, a first object of the present invention is to provide a coagulation / mixing tank capable of uniformly supplying coagulant mixed sludge obtained by uniformly mixing (mixing) sludge and coagulant to a plurality of sludge dewatering (concentration) means. In addition, a second object is to provide a compact sludge dewatering apparatus that can stably operate and dehydrate effectively even agglomerated sludge with a small amount of flocculant added.

As a result of the diligent research conducted by changing the way of thinking, the inventors have found the points described below and have come to realize the present invention.
(1) In addition to a long sludge supply pipe in a vertical type coagulation mixing tank, it is difficult to uniformly supply sludge to a belt-type sludge concentrator having a plurality of rotary pressure dehydrating means and a belt of a predetermined width. Therefore, a horizontally long agglomeration mixing tank disposed horizontally is preferable, but due to the height dimension, the stirring time of the sludge and the aggregating agent is short and uniform mixing is difficult.
However, if a plurality of flocculant supply ports and sludge supply ports are provided in a row along the longitudinal direction of the coagulation / mixing tank, sludge and coagulant are distributed and supplied over the longitudinal direction of the horizontal coagulation / mixing tank. Mix evenly with time stirring.
(2) If a plurality of sludge outlets are provided on the upper side of the horizontally long coagulation mixing tank, an equal amount of mixed sludge can be discharged from each of the plurality of sludge outlets.
(3) If sludge is supplied from the sludge inlet opening below the sludge supply section to the lower side of the dehydration treatment chamber of the rotary pressure dehydration means, the flocs are less likely to be crushed. Can be reduced.
(4) If a coagulation and mixing tank is directly connected to the sludge inlet that opens to the lower side of the sludge supply section, an equal amount of sludge can be supplied to each of the plurality of dewatering treatment chambers of the sludge dewatering equipment. The dehydrating apparatus can be made compact.
(5) Even if the filter plate is rotated in reverse, the sludge in the dehydration chamber can be moved from the lower side to the upper side.
(6) Non-dehydrated sludge having high fluidity does not move to the upper side of the dehydration chamber unless dehydration proceeds and the fluidity decreases.

  Therefore, in order to solve the above-mentioned problem, the means adopted by the agglomeration mixing tank according to claim 1 of the present invention is installed horizontally along the horizontally long tank body and along the longitudinal direction of the tank body. And a stirring means comprising a rotating blade projecting on the outer periphery of the rotating member, and a row in the longitudinal direction of one side surface of the tank body. Sludge dewatering of the coagulant mixed sludge composed of sludge and coagulant provided at the upper part of the tank body, and a plurality of coagulant supply ports for supplying the coagulant to the inside of the tank body And a sludge outlet to be supplied to the means.

  The means employed by the coagulation-mixing tank according to claim 2 of the present invention is the coagulation-mixing tank according to claim 1, wherein one side surface of the tank main body provided with the sludge supply port and the coagulant supply port is: The sludge flow along the inner wall generated by the operation of the stirring means is on the side facing downward.

  The means employed by the coagulation-mixing tank according to claim 3 of the present invention is the coagulation-mixing tank according to any one of claims 1 or 2, wherein the plurality of sludges are disposed on one side of the tank body. The sludge supply tank whose supply port opens to the inner side and the flocculant supply tank whose plurality of flocculant supply ports open to the inner side are provided.

  The means employed by the coagulation-mixing tank according to claim 4 of the present invention is the rotation of the coagulation-mixing tank according to claim 3, wherein the sludge supply tank has an axis parallel to the rotation center of the stirring means. A sludge scraping means for moving the sludge that is rotated by a shaft and stays at the bottom of the sludge supply tank in the direction of the sludge supply port is provided.

  The means employed by the sludge dewatering apparatus according to claim 5 of the present invention is a disk-like shape having a filtration surface that is rotated by a horizontal drive shaft and has a plurality of water permeation holes at least on one side in the width direction. Rotational pressure dehydration provided with a sludge supply section for supplying flocculant mixed sludge with added and mixed flocculant in a dehydration chamber equipped with a filter plate and a dewatered cake discharge section for discharging dehydrated cake In the sludge dewatering treatment apparatus in which the means is disposed, the dewatering cake discharge portion of the rotary pressure dewatering means is located above the rotation center of the disk-shaped filter plate, Provided at a position for discharging from the outer periphery of the dehydration chamber, and the sludge supply unit is provided at a position lower than the dehydrated cake discharge unit and at a position for supplying sludge from the outer periphery of the dehydration chamber to the dehydration chamber. Et And the sludge outlet of the coagulation mixing tank according to any one of claims 1 to 4 is directly connected to a sludge inlet opening below the sludge supply section. Is.

  In the coagulation mixing tank according to claims 1 to 4 of the present invention, a plurality of sludge supply ports and a plurality of coagulant supply ports are arranged in the longitudinal direction of one side surface of the horizontally disposed coagulation mixing tank. Is provided. Therefore, according to the coagulation-mixing tanks according to claims 1 to 4 of the present invention, the sludge and the coagulant are dispersedly supplied from a plurality of positions in the longitudinal direction of the horizontally long coagulation-mixing tank, and the sludge and the coagulant supplied in a dispersed manner are supplied. Are uniformly mixed by the stirring means in the tank body of the coagulation mixing tank.

  In the flocculation / mixing tank according to claims 1 to 4 of the present invention, the sludge outlet is provided in the upper part of the tank body, so that the same amount from each of the plurality of sludge outlets, and the sludge and the flocculant are equal. The flocculant mixed sludge mixed in can be discharged. Therefore, according to the coagulation mixing tanks according to claims 1 to 4 of the present invention, the same amount of sludge and the flocculant are mixed evenly from the plurality of sludge outlets to each of the plurality of rotary pressure dehydrating means. Since the flocculant mixed sludge can be supplied, the maximum sludge dewatering performance can be exhibited in each of the plurality of rotary pressure dewatering means.

  In the flocculation mixing tank according to claim 2 of the present invention, the sludge flow along the inner wall generated by the operation of the stirring means is directed downward on one side surface of the tank body provided with the sludge supply port and the flocculant supply port. The side to become. Therefore, according to the flocculation mixing tank according to claim 2 of the present invention, the sludge and the flocculant supplied into the tank body from the sludge supply port and the flocculant supply port flow downward, and invert at the bottom from downward to upward. In addition, the agglomeration mixing tank is lower in height than the agglomeration mixing tank equipped with a vertical stirring device, but the sludge and the flocculant are mixed. Can be mixed effectively.

  In the flocculation mixing tank according to claim 3 of the present invention, a sludge supply tank in which a plurality of sludge supply ports are opened on the inner side and a plurality of flocculant supply ports are opened on the inner side on a side surface along the longitudinal direction of the tank body. A sludge supply tank is attached. Therefore, according to the flocculation mixing tank according to claim 3 of the present invention, although a plurality of sludge supply ports and a plurality of flocculant supply ports are provided, one sludge supply pipe and one flocculant supply pipe are supplied to each sludge. Since the tank and the flocculant supply tank only need to communicate with each other, the supply pipe system of the sludge supply pipe and the flocculant supply pipe does not become more complicated than the supply pipe system of the flocculent mixing tank according to the conventional example.

  In the agglomeration mixing tank according to claim 4 of the present invention, the sludge that is rotated inside the sludge supply tank by a rotary shaft having an axis parallel to the rotation center of the stirring means and stays at the bottom of the sludge supply tank is Sludge scraping means for moving in the direction of the sludge supply port is provided. Therefore, according to the agglomeration mixing tank according to claim 4 of the present invention, the sludge staying at the bottom of the sludge supply tank is moved in the direction of the sludge supply port by the sludge scraping means and is supplied into the tank body. The sludge supply port is not clogged by sludge staying at the bottom of the sludge supply tank.

  In the sludge dewatering treatment apparatus according to claim 5 of the present invention, the dewatering cake discharge portion of the rotary pressure dewatering means is located above the rotation center of the disk-shaped filter plate and the dewatering cake in the dewatering chamber is on the upper side, and Provided at a position for discharging from the outer periphery of the dehydration chamber, and the sludge supply unit is provided at a position lower than the dehydrated cake discharge unit and at a position for supplying sludge from the outer periphery of the dehydration chamber to the dehydration chamber. The sludge outlet of the coagulation mixing tank according to any one of claims 1 to 4 is directly connected to a sludge inlet opening below the sludge supply section.

  Therefore, according to the sludge dewatering treatment apparatus according to claim 5 of the present invention, the non-dehydrated sludge has high fluidity and does not move to the upper side of the dehydration treatment chamber, and is reliably filtered on the lower side of the dehydration treatment chamber. The fluid moves to the upper side of the dehydration chamber only after the fluidity is lost. Therefore, unlike the conventional rotary pressure dehydrator according to the conventional example, the dewatered cake having a low dewatering rate is not discharged from the discharge port of the dewatered cake discharging unit, and the sludge is stably dewatered. In addition, the sludge is supplied from the sludge inlet opening below the sludge supply section to the lower side of the dehydration treatment chamber of the rotary pressurization dewatering means, and the floc is not easily crushed, so the amount of flocculant added can be reduced. .

  Furthermore, according to the sludge dewatering apparatus according to claim 5 of the present invention, the sludge outlet of the coagulation mixing tank is directly connected to the sludge inlet opening on the lower side of the sludge supply section, and a plurality of rotary pressurizing dewatering means are arranged in parallel. If installed, an equal amount of sludge can be supplied to the dehydration chamber of each rotary pressure dehydration means, so that stable operation can be achieved (the amount of treated sludge and the water content of the dehydrated cake are stable). In addition, since a long sludge supply line is not required, the sludge dewatering apparatus can be made compact and can be installed in a smaller installation space than the conventional example.

  Hereinafter, a sludge dewatering apparatus according to an embodiment of the present invention will be described with reference to the attached drawings. FIG. 1 is a side view of a sludge dewatering apparatus according to an embodiment of the present invention, and FIG. 2 is a rear view of the sludge dewatering apparatus according to the embodiment of the present invention as viewed from the dewatered cake discharge side. FIG. 3 is a longitudinal sectional view of the coagulation mixing tank constituting the sludge dewatering treatment apparatus according to the embodiment of the present invention, and FIG. 4 is a front view of the coagulation mixing tank constituting the sludge dehydration processing apparatus according to the embodiment of the present invention. FIG. 5 (a) is a cross-sectional view of the coagulation mixing tank constituting the sludge dewatering apparatus according to the embodiment of the present invention, FIG. 5 (b) is an enlarged view of part A of FIG. 5 (a), and FIG. c) is a view taken in the direction of arrow B in FIG. 6 is a partially omitted side view showing a schematic configuration of a rotary pressurizing and dehydrating means constituting the sludge dewatering apparatus according to the embodiment of the present invention, FIG. 7 is a sectional view taken along the line CC of FIG. 6, and FIG. It is a side view of the outer ring | wheel spacer of the rotation pressurization dehydration means which comprises the sludge dehydration processing apparatus which concerns on embodiment of this invention.

The code | symbol 1 shown in FIG. 1 and FIG. 2 is the sludge dehydration processing apparatus which concerns on embodiment of this invention.
This sludge dewatering apparatus 1 is provided on a base 3 installed on a base 2 and rotates around a vertical axis of a motor 4 with a speed reducer around a horizontal axis and protrudes left and right. Is provided with a gear box 5 that rotates the same in the same direction. Further, two rotary pressurizing and dehydrating units 10 and 10 'driven by the drive shaft 12 and a chemical solution (not shown) are provided on the base 2 and are respectively provided on the rotary pressurizing and dehydrating units 10 and 10'. A flocculant (polymer flocculant or inorganic flocculant) supplied from the tank is added to and mixed with the raw sludge, and a flocculent mixing tank 30 is provided for supplying the flocculant mixed sludge after tempering. Further, a hopper 6 is provided for receiving the dewatered cake discharged from the dewatered cake discharge port of each of the rotary pressure dewatering means 10 and 10 '. Hereinafter, among the above-described components constituting the sludge dewatering apparatus 1 according to the embodiment of the present invention, the configuration of the coagulation mixing tank 30 and the rotary pressure dehydrating means 10 and 10 'will be described.

  First, the coagulant mixing tank 30 constituting the sludge dewatering treatment apparatus 1 according to the embodiment of the present invention, in which the coagulant mixed sludge conditioned by adding and mixing the raw sludge to the raw sludge is supplied to the rotary pressure dewatering means. Will be described with reference to FIGS. 3, 4 and 5 of the attached drawings. That is, the agglomeration mixing tank 30 according to the embodiment of the present invention is horizontally disposed on the base 2, and a sludge supply tank 36 and a flocculant supply tank 37, which will be described later, are provided on one side surface of the lower part, A sealed tank body 31 is provided with sludge outlets 31b at two upper portions. In the case of the embodiment of the present invention, the sludge outlets 31b are provided in the upper two places, but since the number of the sludge outlets 31b corresponding to the number of the rotary pressurizing and dehydrating means is provided, The number of the sludge outlets 31b is not limited to two.

Inside the tank body 31, one end side is rotatably supported by a drive shaft 32c projecting outward from the one end side of the tank body 31 so as to be watertight, and the other end side is rotatably supported by a driven shaft 32d. A stirrer 32, which is a stirring means, is provided that includes a rotating drum 32a and a flat stirring blade 32b planted at a predetermined pitch in the circumferential direction of the rotating drum 32a.
A driven V belt pulley 32e is fitted on the projecting end of the drive shaft 32c from the tank body 31, and the driven V belt pulley 32e is fitted on the drive shaft of the electric motor 33. It is configured to be rotationally driven by a V-belt 34 hung on 33a. Further, a relay joint 35 is attached to each of the two sludge outlets 31b provided at the upper part of the tank body 31, and one of these relay joints 35 is the right-side rotary pressure dehydrating means 10 in FIG. The other is connected to the sludge inlet of the sludge supply section of the left rotary pressurizing and dehydrating means 10 '.

  The sludge supply tank 36 is one side surface of the tank body 31 and is attached along the longitudinal direction of the tank body 31. The sludge supply tank 36 is supplied with raw sludge (or inorganic flocculant mixed sludge) from a sludge supply source (not shown) via a sludge supply pipe 31a communicating with the side of the sludge supply tank 36. It is configured. Further, the flocculant supply tank 37 is provided on the sludge supply tank 36 and on one side surface of the tank main body 31 along the longitudinal direction of the tank main body 31, and the sludge supply tank 36. Is set to the same length. The flocculant supply tank 37 is supplied with a flocculant (specifically, a polymer flocculant or the like) from a chemical liquid supply tank (not shown) via a chemical liquid supply pipe 31 c communicating with one side surface of the flocculant supply tank 37. It is configured to be. According to the agglomeration mixing tank 30 according to the embodiment of the present invention, a plurality of sludge supply ports 36a and a flocculant supply port 37a are provided, but one sludge supply pipe 31a is provided in the sludge supply tank 36, and Since one flocculant supply pipe 31c only needs to communicate with the flocculant supply tank 37, the supply pipe system of the sludge supply pipe and the flocculant supply pipe is more complicated than the supply pipe system of the flocculent mixing tank according to the conventional example. There is no such thing.

  The inside of the sludge supply tank 36 and the inside of the tank body 31 communicate with each other through a plurality of sludge supply ports 36a provided in a row at a predetermined interval in the longitudinal direction of the tank body 31. The raw sludge supplied from the sludge supply source through the sludge supply pipe 31a is dispersedly supplied from the sludge supply tank 36 through the plurality of sludge supply ports 36a in the longitudinal direction of the tank body 31. Further, the inside of the flocculant supply tank 37 and the inside of the tank body 31 communicate with each other through a plurality of flocculant supply ports 37 a provided in a row at a predetermined interval in the longitudinal direction of the tank body 31. The flocculant supplied from the chemical liquid supply tank (not shown) via the chemical liquid supply pipe 31c is dispersedly supplied in the longitudinal direction of the tank body 31 from the flocculant supply tank 37 through the plurality of flocculant supply ports 37a. It is configured.

  The sludge supply tank 36 is rotated by a rotary shaft having an axis parallel to the rotation center of the stirring device 32, and sludge staying at the bottom of the sludge supply tank is directed to the sludge supply port 36a. A sludge scraping blade 36b which is a sludge scraping means to be moved to is provided. Due to the action of the sludge scraping blade 36b, the sludge staying at the bottom of the sludge supply tank 36 is moved in the direction of the sludge supply port 36a and supplied into the tank body 31, so that it stays at the bottom of the sludge supply tank 36. The sludge supply port 36a is not clogged with sludge. In order to suppress the accumulation of sludge in the sludge supply tank 36, it is preferable to provide the opening of the sludge supply port 36 a at a position near the bottom of the sludge supply tank 36. In this embodiment, the flocculant supply port 37a is provided at the upper position of the sludge supply port 36a. However, these positional relationships may be reversed, and the sludge supply tank 36 It is not necessary to provide the sludge scraping blade 36b inside.

  The opening position of the tank body 31 of the flocculant supply port 37a is set to be directly above the opening position of the tank body 31 of the sludge supply port 36a. In this embodiment, the sludge supply port 36a and the flocculant supply Ten ports 37 a are provided in the longitudinal direction of the tank body 31. The arrangement positions of the sludge supply port 36a and the flocculant supply port 37a are determined in consideration of the counterclockwise rotation direction of the stirrer 32 as shown in FIG.

That is, the sludge and the flocculant supplied into the tank body 31 flow downward, reverse from the downward to the upward at the bottom, and can be stirred throughout the flow along the inner wall on the other side surface. This is because although the height of the mixing tank 3 is lower than that of a conventional coagulation mixing tank equipped with a vertical stirrer, sludge and coagulant can be effectively mixed.
The number of the supply ports 36a and 37a may be determined as appropriate, and is not limited to the number of the supply ports 36a and 37a. In order to more uniformly mix the sludge and the flocculant, it is preferable to provide a baffle plate or the like for making the flow of sludge generated by stirring turbulent in the inside of the tank body 31, for example, the inner wall.

  Next, the rotary pressure dewatering means 10 and 10 'constituting the sludge dewatering apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. 6, 7 and 8 of the attached drawings. Note that the two rotary pressurizing and dehydrating means 10 and 10 'have the opposite configurations, and the components of the rotary pressurizing and dehydrating means 10 and 10' are the same. The rotary pressure dehydrating means 10 shown in FIG. In the description of the operation mode, the reference numerals of the components of the left rotary pressurizing and dehydrating means 10 ′ are the same as those of the components of the right rotary pressurizing and dehydrating means 10.

  Reference numeral 10 shown in FIG. 6 is a rotary pressure dehydrating unit according to the embodiment of the present invention. The basic configuration of the rotary pressure dehydrating means 10 is the same as that according to the conventional example. That is, the rotary pressure dehydrating means 10 includes a drive shaft 12 that is rotated at a rotational speed of 0.5 to 1.3 rpm by an unillustrated electric motor 4 with a speed reducer and a gear box 5. The drive shaft 12 is fitted with an inner ring spacer 13 that is rotated via a sinking key 12 a by the rotation of the drive shaft 12, and an outer ring spacer 14 that surrounds the inner ring spacer 13. The inner ring spacer 13 is provided concentrically with the boss portion 13a, and is configured to be rotated through the boss portion 13a.

  The outer ring spacer 14 is provided with a horizontal partition spacer 15 having a concave curved surface with which the outer peripheral surface of the inner ring spacer 13 is in sliding contact with the center side of the outer ring spacer 14. A sludge inlet 20a opening in the direction is formed. In addition, a dehydrated cake discharge portion 19 that opens in the horizontal direction is provided above the partition spacer 15. Further, the side wall of the partition spacer 15 includes a laterally long groove and a plurality of water outlets opened at the bottom of the groove, and discharges washing water for washing first and second filter plates described later. A washing water discharge part 15a is provided.

  A disc-shaped first filter plate 16 provided with a large number of water permeable holes 16a is provided on the distal end side of the drive shaft 12 protruding from the boss portion 13a of the inner ring spacer 13. Further, a disc-shaped second filter plate 17 having the same configuration as that of the first filter plate 16 and provided with a large number of water permeation holes 17a is provided on the proximal end side of the drive shaft 12. By the way, the punching metal which has the water permeation | transmission hole of 0.5 mm in diameter was used for the 1st filtration plate 16 and the 2nd filtration plate 17 of the rotary pressurization dehydration means which concern on embodiment of this invention. However, the present invention is not limited to this, and in the rotary pressure dehydrating means, the diameter of the water permeation hole of the filter plate is 0.3 to 1.0 mm from the viewpoint of suppressing clogging of sludge into the water permeation hole of the filter plate. It is preferable to set in the range.

  That is, the first filter plate 16 and the second filter plate 17 are attached to the drive shaft 12 by fitting a fitting hole provided at the rotation center thereof. The fitting hole sides of the first filter plate 16 and the second filter plate 17 are fixed by means not shown, and the opposing surfaces of the first and second filter plates 16 and 17 are made by mechanical fastening means (not shown). The inner ring spacer 13 is fixed in close contact with the side surface. The opposing surfaces near the outer periphery of the first and second filter plates 16 and 17 are configured to be in sliding contact with the surface near the inner peripheral portion of the outer ring spacer 14.

  Between the outer peripheral surface of the inner ring spacer 13, the inner peripheral surface of the outer ring spacer 14, the first filter plate 16, and the second filter plate 17, the sludge inlet 20 a is connected to the dehydrated cake discharger 19 side. A dewatering treatment chamber 20 is formed that is divided into a filtration zone 20b for filtering sludge flowing in from the sludge inflow portion 20a and a pressure dewatering zone 20c for pressing and dewatering sludge from which filtered water has been removed. Yes. The sludge inlet 20a is attached with a sludge inlet 18a that opens downward, and a sludge supply unit 18 that supplies sludge to the sludge inlet 20a via a sludge flow path. In addition, what is in the dehydration processing chamber 20 and is in contact with each of the opposite surfaces of the first filter plate 16 and the second filter plate 17 is the first filter plate 16 and the second filter plate. This is a scraper 20 d that scrapes off the cake adhering to each of the surfaces of the plate 17.

  A first cover 21 is disposed outside the first filter plate 6, and a flange portion of the first cover 21 is fixed to a side surface of the outer ring spacer 14. A second cover 22 is disposed outside the second filter plate 16, and a flange portion of the second cover 22 is fixed to a side surface of the outer ring spacer 14. A drain pipe 23 projecting downward is provided at the lower part of each of the first cover 21 and the second cover 22, and is supplied into the dehydration treatment chamber 20 through the sludge supply section 18 and the sludge inlet section 18a. The water in the sludge discharged into the first cover 21 and the second cover 22 through the multiple water permeation holes 16a and 17a provided in the first and second filter plates 16 and 17 is The drain pipe 23 is configured to drain out of the machine.

  The sludge supply unit 18 is formed in a shape that does not prevent the dehydrated cake discharged from the discharge port 19a of the dehydrated cake discharge unit 19 from dropping downward. Specifically, as is well understood from FIGS. 3 and 5, the protruding size of the sludge supply unit 18 in the left direction in the drawing is smaller than the protruding size of the dewatered cake discharge unit 19 in the left direction in the drawing. It is set to be a dimension. Therefore, one end of a dehydrated cake carrying / receiving means such as a dehydrated cake conveying conveyor for conveying the dehydrated cake discharged from the dehydrated cake discharging unit 19 and a hopper for receiving the dehydrated cake is disposed below the dehydrated cake discharging unit 19. Therefore, the sludge supply unit 18 does not interfere with the arrangement of the dewatered cake carrying / receiving means.

  Furthermore, the back opening 19a of the dewatering cake discharge unit 19 is applied with a back pressure against the compressed dewatered sludge in the press dewatering zone 20b of the dewatering treatment chamber 20, and the width of the upper portion of the discharge port 19a is narrowed. A back pressure plate 24 comprising an upper back pressure plate 24a and a lower back pressure plate 24b that narrows the lower partial width dimension of the discharge port 19a is provided. The back pressure plate 24 is configured to be pressed by an air spring (not shown) that is a control means.

Hereinafter, the operation mode of the sludge dewatering apparatus 1 according to the embodiment of the present invention will be described. That is, according to the sludge dewatering apparatus 1 according to the embodiment of the present invention, raw sludge from a sludge supply source (not shown) is pressurized to a maximum of 100 kPa (about 1.0 kgf / cm ² ) by a sludge press-fitting pump and supplied with sludge. It is supplied to the sludge supply tank 36 through the pipe 31a. In parallel with the supply of the raw sludge to the sludge supply tank 36, a flocculant pressurized to the same pressure as the raw sludge from a chemical supply tank (not shown) is supplied to the flocculant supply tank 37 via the flocculant supply pipe 31c. The The raw sludge supplied to the sludge supply tank 36 is from each of the ten sludge supply ports 36a, and the flocculant supplied to the coagulant supply tank 37 is from each of the ten flocculant supply ports 37a. 30 tank bodies 31 are distributed and supplied in parallel. The raw sludge and the flocculant dispersedly supplied in the coagulation mixing tank 30 are gently stirred by the stirring blade 32b that rotates gently (for example, the rotational speed of 10 to 250 rpm) of the stirring device 32. The flocculant is evenly mixed and tempered to flocculate.

  More specifically, the raw sludge and the flocculant flow downward in the tank body 31, reverse in the bottom region, and continue to be mixed throughout while rising upward. Then, an equal amount of flocculant mixed sludge mixed and agglomerated (flocculated) flows out from each of the sludge outlets 31b and 31b provided at the two upper portions of the tank body 31. Therefore, according to the agglomeration mixing tank 30 according to the embodiment of the present invention, the agglomeration is equivalent to each of the rotary pressure dehydrating means 10 and 10 'and the sludge and the aggregating agent are evenly mixed. Since the agent-mixed sludge can be supplied, the maximum sludge dewatering performance can be exhibited in each of the plurality of rotary pressure dewatering means 10, 10 '.

  Then, the coagulant mixed sludge flowing out from each of the sludge outlets 31b and 31b in an equal amount is rotated and pressurized dewatering means 10, 10 via a relay joint 35 connected to the upper ends of the sludge outlets 31b and 31b. The sludge inlet 18a opened to the lower side of the sludge inlet 18a and gradually rises and slowly passes through the sludge flow path and the sludge inlet 20a. Continuously supplied to the filtration zone 20b below the dehydration chamber 20 rotated at a speed. Since the flocculant mixed sludge supplied to the lower filtration zone 20b of the dehydration treatment chamber 20 is filtered in the filtration zone 20b, the fluidity is gradually lost.

The sludge whose fluidity has been reduced by filtration in the filtration zone 20b gradually forms cake layers on the surfaces of the disk-shaped first filter plate 16 and the second filter plate 17 provided with a large number of water permeation holes. The first filter plate 16 and the second filter plate 17 move to the squeeze dehydration zone 20c side by rotation. Since the trapping of the solid matter is improved by the cake layer formed on the surfaces of the first filter plate 16 and the second filter plate 17, the filtrate is cleaned. The sludge in the pressure dewatering zone 20c has a maximum back pressure of 600 kPa (approximately 6.kPa) by pressing force control (pressure control of the air spring) of the back pressure plate 24 provided at the discharge port 19a of the dewatered cake discharge unit 19. 0 kgf / cm ² ) is kept at a constant pressure (adjustable). The sludge that has lost its fluidity is squeezed and dehydrated by the shearing force generated by the first filter plate 16 and the second filter plate 17 and the back pressure generated by the back pressure plate 24. Then, the dehydrated cake having a low water content that has been pressed and dehydrated is pushed out of the back pressure plate 24 and discharged from the dehydrated cake discharge unit 19 to the outside of the machine.

  Therefore, according to the sludge dewatering treatment apparatus 1 according to the embodiment of the present invention, the non-dehydrated sludge has a high fluidity, so that it does not move to the press dewatering zone 20c on the upper side of the dewatering treatment chamber 20, and the dewatering treatment chamber. It moves to the pressing dehydration zone 20c of the upper part side of the dehydration processing chamber 20 only after it is filtered reliably in the lower filtration zone 20b of 20 and fluidity is lost. Therefore, unlike the conventional sludge dewatering apparatus, the dewatered cake having a low dewatering rate is not discharged from the discharge port of the dewatered cake discharging unit 19, and the sludge is stably dewatered.

Incidentally, in the rotary pressurization dehydrator according to the conventional example, undehydrated sludge was discharged several times in 6 hours at most, but in the case of this sludge dewatering treatment apparatus 1, such a phenomenon is seen. There wasn't.
Furthermore, in the case of the conventional example, depending on the setting of the operating conditions, even when the dehydrated cake is discharged from the dehydrated cake discharge section, a small amount of water was always dripping from the lower part of the dehydrated cake. In the dehydration apparatus 1, such dripping of water was not observed at all. In addition, in the rotary pressure dehydrator according to the conventional example, the supply amount of the flocculant mixed sludge is uneven due to the difference in the pipe resistance to the two rotary pressure dehydration means (dehydration treatment chamber) and the slight difference in the dewaterability. Then, this difference gradually increased and one side became poorly dewatered, and there was a case where a lot of flocculant mixed sludge was supplied to the dewatering treatment chamber side and undehydrated sludge was discharged. In this case, such a phenomenon was not observed, and sludge was uniformly supplied to the dehydration chambers of the two rotary pressure dehydrating means, and the moisture content of the dehydrated cake was stable.

  Further, the sludge rises slowly from the coagulation mixing tank 30, and the sludge is removed from the coagulation mixing tank 30 through the sludge inlet 18a that opens to the lower side of the sludge supply section 18 with a short moving distance. Since the flocs are not easily crushed by the configuration of supplying to the filtration zone 20b on the lower side of the dehydration treatment chamber 20, the amount of the polymer flocculant added can be reduced, which can greatly contribute to the reduction of sludge treatment costs. Furthermore, since the coagulation mixing tank 30 is directly connected to the sludge inlet 18a that opens to the lower side of the sludge supply section 18, a plurality (2 in the embodiment of the present invention) of the rotary pressure dehydrating means 10, 10 'are provided. In addition to being able to supply an equal amount of sludge to each, a long sludge supply line is not required, so the sludge dewatering treatment device 1 can be made compact and installed in a narrower space than before. can do.

  By the way, in the case of the rotary pressure dehydrating means, in general, the moisture content of the lower part of the dewatered cake that moves on the rotation center side of the dehydration chamber and is discharged from the discharge port 19a is moved on the outer peripheral side and discharged to the discharge port 19a. It becomes lower than the moisture content of the upper part of the dehydrated cake discharged from, and the moisture content distribution in the vertical direction of the dehydrated cake varies. Incidentally, when the moisture content of the lower part of the dehydrated cake discharged from the outlet having the same upper and lower width dimensions was 80.7%, the moisture content of the upper part of the dehydrated cake was 86.7%. The moisture content of the lower part of the dehydrated cake discharged from the outlet is lower than the moisture content of the upper part of the dehydrated cake, because the partition spacer 15 moves to the rotational center side of the dewatering treatment chamber 20. It can be understood that the resistance acting on the sludge is larger than the resistance acting on the sludge moving on the outer peripheral side, and the squeezing and dewatering effect is further increased.

  However, in the sludge dewatering apparatus 1 according to the embodiment of the present invention, as described above, the back pressure plate 24 provided at the discharge port 19a of each of the dewatered cake discharge portions 19 of the rotary pressure dewatering means 10 and 10 ' The upper back pressure plate 24a narrows the width of the upper portion of the discharge port 19a and the lower back pressure plate 24b of the lower portion of the discharge port 19a. The upper back pressure plate 24a and the lower back pressure plate 24b A control means (air spring) for individually controlling each of the above is provided. Therefore, by pressing the upper back pressure plate 24a with a pressing force stronger than that of the lower back pressure plate 24b, the width of the upper portion in the vertical direction of the discharge port 19a is controlled to be smaller than the width of the lower portion. Since the moisture content of the sludge moving on the outer peripheral side of the dehydration treatment chamber 20 can be lowered like the moisture content of the sludge moving on the rotation center side, it is greatly improved in the uniform moisture content distribution in the vertical direction of the dehydrated cake. Can contribute.

  In the sludge dewatering treatment apparatus 1 according to the embodiment of the present invention, the case where two rotary pressure dehydrating units (dehydration processing chambers) are provided in the rotary pressure dehydrator has been described as an example. The rotary pressure dehydrator may be provided with three or more rotary pressure dehydrating means (dehydration processing chambers). Moreover, although the case where the disk-shaped filter plate which has the filtration surface in which many water permeation holes are provided is arrange | positioned at the both sides of the width direction of a dehydration process chamber was demonstrated as an example, the width | variety of a dehydration process chamber If a disk-shaped filter plate is provided in any one of the directions, an appropriate effect can be obtained. Moreover, although the case where punching metal was used for the filter plate was demonstrated, if it is a member which can isolate | separate sludge and a water | moisture content, such as a wedge wire screen, it can utilize. Therefore, the sludge dewatering apparatus according to the above embodiment is only one specific example of the present invention, and design changes and the like within a range not departing from the technical idea of the present invention are free. The form is not limited to the form of the sludge dewatering apparatus 1 according to the above embodiment.

  Furthermore, in the sludge dewatering apparatus according to the embodiment of the present invention, as described above, the case where the coagulation mixing tank is applied to the rotary pressure dewatering means has been described as an example. However, this agglomeration mixing tank is transported with, for example, an endless belt having a width of several meters and having water permeability formed across a pair of rollers supported by a frame, and dewatering is performed during the transportation. The present invention can also be applied to a belt-type sludge concentrator that goes and concentrates sludge. When applying a flocculation / mixing tank to such a belt-type sludge concentrator, the upper part of the tank body of the flocculation / mixing tank is made open, and is constructed integrally with the frame of the belt-type sludge concentrator. What is necessary is just to comprise so that sludge may be supplied from the upper opening (opening provided in the longitudinal direction of the tank main body) of the tank main body of a mixing tank so that it may flow substantially parallel to the direction of a belt. If the flocculation / mixing tank of the present invention is applied to a belt-type sludge concentrator, the amount of flocculant added can be reduced, and homogeneous flocculated sludge is evenly supplied in the width direction of the belt. Can be concentrated. Therefore, the agglomeration mixing tank according to the technical idea of the present invention is not limited to application to the rotary pressure dehydrating means.

It is a side view of the sludge dehydration processing apparatus concerning an embodiment of the invention. It is the rear view which looked at the sludge dehydration processing apparatus concerning an embodiment of the invention from the dehydrated cake discharge side. It is a longitudinal cross-sectional view of the coagulation mixing tank which comprises the sludge dehydration processing apparatus which concerns on embodiment of this invention. It is a front view of the coagulation mixing tank which comprises the sludge dehydration processing apparatus which concerns on embodiment of this invention. FIG. 5 (a) is a cross-sectional view of the coagulation mixing tank constituting the sludge dewatering apparatus according to the embodiment of the present invention, FIG. 5 (b) is an enlarged view of part A in FIG. 5 (a), and FIG. ) Is a view on arrow B in FIG. It is a partially omitted side view showing a schematic configuration of a rotary pressurizing and dehydrating means constituting the sludge dewatering apparatus according to the embodiment of the present invention. It is CC sectional view taken on the line of FIG. It is a side view of the outer ring | wheel spacer of the rotation pressurization dehydration means which comprises the sludge dehydration processing apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sludge dehydration processing apparatus, 2 ... Base, 3 ... Mount, 4 ... Electric motor with a reduction gear, 5 ... Gear box, 6 ... Hopper 10 ... Rotary pressure dehydration means, 10 '... Rotary pressure dehydration means 12 ... Drive shaft , 12a ... Sink key 13 ... Inner ring spacer, 13a ... Boss part 14 ... Outer ring spacer 15 ... Partition spacer, 15a ... Washing water discharge part 16 ... First filter plate, 16a ... Water permeation hole 17 ... Second filter plate, 17a ... Water permeation hole 18 ... sludge supply section, 18a ... sludge inlet 19 ... dewatered cake discharge section, 19a ... discharge port 20 ... dewatering treatment chamber, 20a ... sludge inlet, 20b ... filtration zone, 20c ... squeeze dewatering zone, 20d ... scraper DESCRIPTION OF SYMBOLS 21 ... 1st cover 22 ... 2nd cover 23 ... Drain pipe 24 ... Back pressure plate, 24a ... Upper back pressure plate, 24b ... Lower back pressure plate 30 ... Coagulation mixing tank 31 ... Tank main body, 31a ... Sludge supply pipe, 31 b ... sludge outlet, 31c ... chemical supply pipe 32 ... stirring device, 32a ... rotating drum, 32b ... stirring blade, 32c ... drive shaft, 32d ... driven shaft, 32e ... driven V belt pulley 33 ... motor, 33a ... drive V belt Pulley 34 ... V belt 35 ... Relay joint 36 ... Sludge supply tank, 36a ... Sludge supply port, 36b ... Sludge scraping blade 37 ... Flocculant supply tank, 37a ... Flocculant supply port

Claims (5)

  Stirring means comprising a horizontally long tank body disposed horizontally, a rotating member provided along the longitudinal direction of the tank body, and stirring blades protruding from the outer periphery of the rotating member, and the tank body A plurality of sludge supply ports for supplying sludge to the inside of the tank body and a plurality of flocculant supply ports for supplying a flocculant to the inside of the tank body, An agglomeration mixing tank comprising an upper part of the tank main body and a sludge outlet for supplying a flocculant mixed sludge composed of sludge and a flocculant to sludge dewatering means.   The one side surface of the tank body provided with the sludge supply port and the flocculant supply port is a side on which the sludge flow along the inner wall generated by the operation of the stirring means is directed downward. The agglomeration mixing tank described in 1.   A sludge supply tank in which the plurality of sludge supply ports open to the inner side and a flocculant supply tank in which the plurality of flocculant supply ports open to the inner side are attached to one side surface of the tank body. The agglomeration mixing tank according to any one of claims 1 and 2, characterized in that   Sludge scraping that moves inside the sludge supply tank with a rotary shaft having an axis parallel to the rotation center of the stirring means and moves sludge staying at the bottom of the sludge supply tank in the direction of the sludge supply port. Means are provided, The coagulation mixing tank of Claim 3 characterized by the above-mentioned.   A flocculant was added and mixed in a dehydration chamber equipped with a disk-shaped filter plate having a filtration surface that is rotated by a horizontal drive shaft and provided with a large number of water permeation holes on at least one side in the width direction. In the sludge dewatering treatment apparatus comprising a sludge supply section for supplying the coagulant mixed sludge and a rotary pressure dewatering means provided with a dewatered cake discharge section for discharging the dewatered cake The dewatering cake discharge part of the means is provided at a position above the rotation center of the disk-shaped filter plate and the drainage cake in the dewatering process chamber at a position for discharging from the outer periphery of the dewatering process chamber. Is provided at a position lower than the dewatering cake discharge section and at a position for supplying sludge from the outer periphery of the dewatering chamber to the dewatering chamber, and at a sludge inlet opening below the sludge supplying section. Sludge dewatering apparatus, characterized in that the sludge outlet of the mixing flocculation tank according is directly connected to one of of the preceding claims 1 to 4.

Images