JP2010057997A - Sludge dewatering apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sludge dewatering apparatus which achieves uniform sludge supply to a belt press type dehydrator by pulverizing concentrated sludge flocs with a simple structure. <P>SOLUTION: The sludge dewatering apparatus comprises a sludge flocculation tank 1, a sludge thickener 2 accommodating a filter cylinder in an outer cylinder, rotatably accommodating a screw in the filter cylinder, making water contained in coagulated sludge pass through the filtering surface of the filter cylinder and discharging the water as a separate liquid to concentrate the coagulated sludge while conveying the coagulated sludge introduced from the sludge flocculation tank 1 into the filter cylinder by rotating and driving the screw and discharging the concentrated sludge from the inside of the filter cylinder by a sludge discharge pump 7, and the belt press type dehydrator 3 having a gravity dewatering part for separating water by gravity from the concentrated sludge supplied from the sludge thickener 2 by the sludge discharge pump 7 through a sludge supply pipe 5, wherein a ball valve 8 for fragmenting the flocs of the concentrated sludge is installed in the sludge supply pipe 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sludge aggregating tank, a sludge concentrating device, a sludge dewatering device equipped with a belt press type dehydrator, and a method carried out using the sludge dewatering device.

  In order to dispose or incinerate various sludges such as sludge generated in sewage sludge and industrial wastewater treatment, sludge is dehydrated with a dehydrator. It is difficult to do well. For this reason, prior to the dewatering treatment by the sludge dewatering machine, the sludge is agglomerated with a flocculant in a sludge agglomeration tank to form a floc, and the flocculent agglomerated sludge is supplied to a sludge concentrating device, from which moisture And the sludge is concentrated. Then, the concentrated sludge concentrated by the sludge concentrator is supplied to a dehydrator, dehydrated, and discharged as a dehydrated cake.

  By the way, as a dehydrator, for example, a belt press type dehydrator is known, but when the concentrated sludge is supplied from the sludge concentrator to the gravity dehydrator of the belt press type dehydrator, the concentrated sludge is evenly spread as much as possible. Supplying a uniform thickness with no unevenness is necessary for improving the subsequent dewatering performance and preventing the filter cloth from meandering and the like to stably operate the dehydrator.

  Therefore, for example, in Patent Document 1, a sludge retaining portion consisting of a weir weir at the front portion of the feed mud hopper of the belt press type dehydrator, and an overflow weir provided at the rear thereof is formed in front of the sludge retaining portion, A technique for providing a rake reciprocating sludge leveling device that reciprocates in a direction perpendicular to the front-rear direction in which sludge is guided has been proposed.

In Patent Document 2, a plurality of sludge outlets provided in the mixing tank main body of the belt press type dehydrator are provided in the circumferential direction of the arc surface, and each outlet end portion is the width of the inlet of the mud hopper of the belt press. A technique has been proposed in which the outlets are arranged in a distributed manner in such a manner that these outlets can be opened and closed sequentially by a mud opening closing plate that rotates along the arcuate surface.
Japanese Utility Model Publication No. 61-059488 Japanese Utility Model Publication No. 62-005829

  However, when a sludge concentrator and a belt press dehydrator are combined, the concentration of concentrated sludge supplied from the sludge concentrator to the belt press dehydrator is high. There is a problem that the apparatus does not spread and the thickness of the dewatered cake becomes non-uniform, making it difficult to operate the apparatus.

  Further, according to the techniques proposed in Patent Documents 1 and 2, there is a problem that the device configuration becomes complicated.

  In addition, as a method to achieve uniform mud supply to the belt press type dehydrator, a method of lowering the concentrated sludge concentration, a method of lowering the addition rate of the flocculant in the sludge coagulation tank, and the stirring strength of the sludge in the sludge coagulation tank However, if the concentrated sludge concentration is lowered, it is necessary to increase the driving speed of the filter cloth of the belt press dehydrator, which may cause a decrease in dewatering performance. Also, if the addition rate of the flocculant in the sludge coagulation tank is lowered, the strength of the sludge flocs will decrease, and stable operation will not be possible if the sludge properties change, increasing the sludge agitation strength in the sludge coagulation tank. Then, the problem that the sludge floc refines | miniaturizes and the filtration performance in a sludge concentration apparatus falls will generate | occur | produce.

  The present invention has been made in view of the above problems, and the object of the treatment is a sludge dewatering device and a sludge capable of uniformly supplying mud to a belt press type dehydrator by refining the concentrated sludge floc with a simple configuration. It is to provide a dehydration method.

In order to achieve the above object, the invention according to claim 1
A sludge agglomeration tank;
A filter cylinder is accommodated in the outer cylinder, a screw is rotatably accommodated inside the filter cylinder, and the screw is rotated to drive the sludge to be introduced into the filter cylinder from the sludge coagulation tank. While, the moisture contained in the coagulated sludge passes through the filtration surface of the filter cylinder and is discharged as a separation liquid to concentrate the sludge, and the concentrated concentrated sludge is discharged from the inside of the filter cylinder by a sludge discharge pump. A sludge concentrating device,
A belt press type dehydrator having a gravity dewatering unit that separates moisture by gravity from the concentrated sludge supplied from the sludge concentrator via the sludge supply pipe by the sludge discharge pump;
In the sludge dewatering device equipped with
A ball valve for subdividing flocs of concentrated sludge is installed in the mud supply pipe.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, a pressure gauge is installed in the mud supply pipe.

The invention described in claim 3
A sludge agglomeration tank;
A filter cylinder is accommodated in the outer cylinder, a screw is rotatably accommodated inside the filter cylinder, and the screw is rotated to drive the sludge to be introduced into the filter cylinder from the sludge coagulation tank. While, the moisture contained in the coagulated sludge passes through the filtration surface of the filter cylinder and is discharged as a separation liquid to concentrate the sludge, and the concentrated concentrated sludge is discharged from the inside of the filter cylinder by a sludge discharge pump. A sludge concentrating device,
A belt press type dehydrator having a gravity dewatering unit that separates moisture by gravity from the concentrated sludge supplied from the sludge concentrator via the sludge supply pipe by the sludge discharge pump;
In the sludge dewatering method using the sludge dewatering device equipped with
A ball valve for subdividing the floc of the concentrated sludge and a pressure gauge for detecting the pressure of the concentrated sludge flowing through the mud supply pipe are installed in the mud supply pipe, and based on the pressure value detected by the pressure gauge, The opening degree is adjusted.

  According to the first aspect of the present invention, the floc of the concentrated sludge supplied from the sludge concentrating device to the belt press dehydrator by the mud supply pipe is refined by the ball valve installed in the mud supply pipe. With this configuration, uniform mud supply to the belt press type dehydrator is possible, and the dewatering performance is improved and the dewatered cake is made uniform, so that the apparatus can be operated stably.

  According to the second and third aspects of the invention, since the opening of the ball valve is adjusted according to the pressure of the concentrated sludge flowing through the mud supply pipe, the floc of the concentrated sludge has an appropriate size according to the concentrated sludge concentration. In addition, the uniform mud supply to the belt press type dehydrator is made stable.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a system configuration diagram of a sludge dewatering apparatus according to the present invention, FIG. 2 is a basic configuration diagram of a sludge aggregating tank and a sludge concentrating device of the sludge dewatering apparatus, and FIG. 3 is a gravity of a belt press type dehydrator of the sludge dewatering apparatus. It is a sectional side view of a dehydration part.

  As shown in FIG. 1, the sludge dewatering apparatus according to the present invention includes a sludge flocculating tank 1, a sludge concentrating apparatus 2, and a belt press type dewatering machine 3. The sludge flocculating tank 1 and the sludge concentrating apparatus 2 are flocculated sludge. The sludge concentrator 2 and the belt press dehydrator 3 are connected by a pipe 4 and are connected by a mud supply pipe (concentrated sludge pipe) 5. Further, a separation liquid pipe 6 is led out from the sludge concentrating device 2.

  Although the sludge discharge pump 7 is provided in the mud supply pipe 5, the present invention provides a ball valve 8 for subdividing flocs of concentrated sludge and a pressure gauge 9 for detecting the pressure of the concentrated sludge flowing through the mud supply pipe 5. Is installed in the mud supply pipe 5 and the opening of the ball valve 8 is adjusted based on the pressure value detected by the pressure gauge 9.

  Thus, in the sludge dewatering apparatus according to the present invention, the agglomerated sludge formed by adding a flocculant to the sludge in the sludge agglomeration tank 1 is introduced from the agglomerated sludge pipe 4 to the sludge concentrator 2 to concentrate the sludge. The agglomerated sludge introduced into the apparatus 2 is concentrated to become concentrated sludge. The concentrated sludge is supplied from the mud supply pipe 5 to the belt press dehydrator 3 by the sludge discharge pump 7 and dehydrated, and is discharged as a dehydrated cake. Further, the separation liquid separated from the coagulated sludge in the sludge concentration device 2 is discharged to the outside from the separation liquid pipe 6.

  Next, the configuration and action of the sludge aggregation tank 1 and the sludge concentrator 2 will be described with reference to FIG.

  The sludge agglomeration tank 2 is a cylindrical tank-like container having an open upper surface, and a raw mud pipe 10 is connected to the lower part thereof, and a stirrer 12 that is rotationally driven by a motor 11 is provided inside. Further, the coagulated sludge pipe 4 extends substantially horizontally from the upper part of the sludge coagulation tank 1.

  Further, the sludge concentrating device 2 has a cylindrical filter cylinder 14 disposed vertically in a cylindrical tank-shaped outer cylinder 13 having a sealed structure, and a spiral screw 15 is rotatably accommodated in the filter cylinder 14. Configured.

  Here, the peripheral surface of the filter cylinder 14 facing the inside of the outer cylinder 13 constitutes a filtration surface 14a made of a punching plate, a wedge wire, or the like. The extending coagulated sludge pipe 4 is connected. Further, the mud supply pipe 5 is led out horizontally from the lower part of the filter cylinder 14, and the sludge discharge pump 7, the ball valve 8 and the pressure gauge 9 are installed in the middle thereof as described above. The separation liquid pipe 6 is led out from the outer cylinder 13.

  The spiral screw 15 is formed by spirally winding a screw blade 15b around a rotating shaft 15a, and a motor 16 as a drive source is connected to the rotating shaft 15a. The outer diameter of the spiral screw 15 is set to be slightly smaller than the inner diameter of the filtration surface 14a of the filtration cylinder 14, and a small gap is formed between the outer peripheral edge of the spiral screw 15 and the filtration surface 14a of the filtration cylinder 14. Is formed.

  Thus, sludge (raw mud) is supplied from the raw mud pipe 10 to the sludge agglomeration tank 1, and a flocculant such as a polymer is added to the sludge flowing through the raw mud pipe 10, and the flocculant is added. The sludge is agitated by the agitator 12 in the sludge agglomeration tank 1, and the solid component contained in the sludge is flocked to become agglomerated sludge.

Here, the sludge liquid level h ₂ in the filter cylinder 14 is set lower than the sludge liquid level h ₁ in the sludge agglomeration tank 1 (h ₂ <h ₁ ), and both liquid levels h ₁ and h _{2 are set.} (Head difference) Δh ₁₂ (= h ₁ −h ₂ ), the agglomerated sludge in the sludge agglomeration tank 1 passes through the agglomerated sludge pipe 4 and enters the filtration cylinder 14 of the sludge concentrator 2. It is introduced from.

In the sludge concentrating device 2, the spiral screw 15 is driven to rotate at a predetermined speed in the filter cylinder 14 by the motor 16, and the aggregated sludge introduced into the filter cylinder 14 is moved downward by the rotating spiral screw 15. While being conveyed, the moisture contained therein passes through the filtration surface 14a of the filtration cylinder 14 and is stored in the outer cylinder 13 as a separation liquid. Here, since the water level h ₃ of the separation liquid in the separation liquid pipe 6 is set lower than the liquid level h ₂ in the filter cylinder 14 (h ₃ <h ₂ ), both of h ₂ and h ₃ With the differential pressure based on the difference (head difference) Δh ₂₃ (= h ₂ −h ₃ ) as the filtration pressure, the water separated from the aggregated sludge passes through the filtration surface 14a of the filtration cylinder 14 and enters the separation liquid in the outer cylinder 13. As housed. In this case, since the outer cylinder 13 is disposed below the water level h3 of the separation liquid, the separation liquid accommodated in the outer cylinder 13 is filled in the outer cylinder 13, and the separation liquid is filtered into the separation liquid. The filtration surface 14a of the cylinder 14 will be buried.

  Then, the separation liquid accommodated in the outer cylinder 13 is discharged to the outside from the separation liquid pipe 6 connected to the outer cylinder 13. Further, the coagulated sludge conveyed downward in the filter cylinder 14 by the rotation of the spiral screw 15 is concentrated to become concentrated sludge by separating water in the middle, and this concentrated sludge is converted by the sludge discharge pump 7. It is supplied to the belt press type dehydrator 3 through the mud supply pipe 5 to be dehydrated.

  Thus, in this embodiment, since the ball valve 8 is installed in the mud supply pipe 5 as described above, flocs of concentrated sludge supplied from the sludge concentrator 2 to the belt press dehydrator 3 by the sludge discharge pump 7. Is refined by the ball valve 8. For this reason, it is possible to uniformly feed mud to the belt press dehydrator 3 with a simple configuration in which the ball valve 8 is simply installed in the mud supply pipe 5, improving the dewatering performance of the belt press dehydrator 3 and dewatering cake. The belt press type dehydrator 3 can be stably operated.

  And in this Embodiment, the pressure gauge 9 is installed in the mud supply pipe 5, the pressure of the concentrated sludge which flows through the mud supply pipe 5 is detected by the pressure gauge 9, and the opening degree of the ball valve 8 is determined according to the detected value. Therefore, the floc of the concentrated sludge is refined to an appropriate size according to the concentration, and the uniform mud supply to the belt press type dehydrator 3 is more reliably and stably performed.

  In the present embodiment, the concentration of the concentrated sludge discharged from the sludge concentrating device 2 to the mud supply pipe 5 is around 4%, and the floc diameter is 7 to 8 mm. A 50A hose was used as the mud supply pipe 5, a 40A ball valve 8 was installed therein, and the opening of the ball valve 8 was adjusted while checking the pressure with a pressure gauge 9. When the opening of the ball valve 8 is reduced, the floc diameter of the concentrated sludge becomes small, the opening is 50% (handle angle 45 °), the pressure is about 0.02 to 0.05 MPa, the floc diameter is about 2 mm, belt press type The concentrated sludge spreads left and right in the mud supply section of the dehydrator 3, and the thickness of the resulting dewatered cake became almost uniform.

  Next, the structure of the gravity dehydration part of the belt press dehydrator 3 will be described with reference to FIG.

  In FIG. 3, 17 is an endless filter cloth belt that runs in the direction of the arrow shown in the figure, 18 is a mud supply frame, and this mud supply frame 18 has two opposing side walls 18a (only one is shown in FIG. 3). And a rear wall 18b for connecting the rear ends of the both side walls 18a, and the lower edge of the rear wall 18b is slightly separated from the filter cloth belt 17 so as to surround the mud supply position. Reference numeral 19 denotes a seal member, and 5 denotes the mud supply pipe. An end of the mud supply pipe 5 is opened above the mud supply part.

  The belt press type dehydrator 3 includes a wedge effect dewatering unit (not shown) and a pressure dewatering unit in addition to the gravity dewatering unit (refer to Patent Documents 1 and 2 for details).

  Thus, the concentrated sludge supplied from the mud supply pipe 5 to the mud supply section of the gravity dewatering section is spread uniformly from side to side since the flocs are subdivided by the ball valve 8 as described above. It is dehydrated by the action of gravity in the dehydrating part. The concentrated sludge dewatered in the gravity dewatering unit is sequentially dewatered in a wedge effect dewatering unit and a compression dewatering unit (not shown), and finally discharged as a dewatered cake.

1 is a system configuration diagram of a sludge dewatering apparatus according to the present invention. It is a basic block diagram of the sludge aggregation tank and the sludge concentration apparatus of the sludge dehydration apparatus which concerns on this invention. It is a sectional side view of the gravity dehydration part of the belt press type dehydrator of the sludge dewatering device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sludge coagulation tank 2 Sludge concentrator 3 Belt press type dehydrator 4 Coagulated sludge pipe 5 Supply mud pipe 6 Separation liquid pipe 7 Sludge discharge pump 8 Ball valve 9 Pressure gauge 10 Raw mud pipe 11 Motor 12 Stirrer 13 Outer cylinder 14 Filter cylinder 14a Filtration surface of filter cylinder 15 Spiral screw 15a Rotating shaft of spiral screw 15b Screw blade of spiral screw 16 Motor 17 Filter cloth belt 18 Mud supply frame 18a Side wall of mud supply frame 18b Rear wall of mud supply frame 19 Seal member

Claims (3)

A sludge agglomeration tank;
A filter cylinder is accommodated in the outer cylinder, a screw is rotatably accommodated inside the filter cylinder, and the screw is rotated to drive the sludge to be introduced into the filter cylinder from the sludge coagulation tank. While, the moisture contained in the coagulated sludge passes through the filtration surface of the filter cylinder and is discharged as a separation liquid to concentrate the sludge, and the concentrated concentrated sludge is discharged from the inside of the filter cylinder by a sludge discharge pump. A sludge concentrating device,
A belt press type dehydrator having a gravity dewatering unit that separates moisture by gravity from the concentrated sludge supplied from the sludge concentrator via the sludge supply pipe by the sludge discharge pump;
In the sludge dewatering device equipped with
A sludge dewatering apparatus, wherein a ball valve for subdividing flocs of concentrated sludge is installed in the mud supply pipe.   2. The sludge dewatering apparatus according to claim 1, wherein a pressure gauge is installed in the transfer pipe. A sludge agglomeration tank;
A filter cylinder is accommodated in the outer cylinder, a screw is rotatably accommodated inside the filter cylinder, and the screw is rotated to drive the sludge to be introduced into the filter cylinder from the sludge coagulation tank. While, the moisture contained in the coagulated sludge passes through the filtration surface of the filter cylinder and is discharged as a separation liquid to concentrate the sludge, and the concentrated concentrated sludge is discharged from the inside of the filter cylinder by a sludge discharge pump. A sludge concentrating device,
A belt press type dehydrator having a gravity dewatering unit that separates moisture by gravity from the concentrated sludge supplied from the sludge concentrator via the sludge supply pipe by the sludge discharge pump;
In the sludge dewatering method using the sludge dewatering device equipped with
A ball valve for subdividing the floc of the concentrated sludge and a pressure gauge for detecting the pressure of the concentrated sludge flowing through the mud supply pipe are installed in the mud supply pipe, and based on the pressure value detected by the pressure gauge, A sludge dewatering method characterized by adjusting the opening.

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