JP5564877B2 - Electroosmosis dehydrator - Google Patents

Description

  The present invention relates to an electroosmotic dewatering device for dewatering water-containing materials such as wastewater biologically treated sludge and clean water sludge. In particular, the water-treated material on a conveyor belt is pressed by an upper electrode plate. The present invention relates to an improvement of the constructed electroosmotic dehydrator.

  Electroosmotic dehydration is well known as a method for dehydrating hydrated substances such as sludge generated during biological treatment of wastewater (Patent Documents 1 to 3). In this electroosmosis dehydration treatment, the water to be treated is energized to attract the negatively charged sludge to the anode side, while dewatering by applying pressure while moving the sludge pore water to the cathode side for separation. Therefore, compared with the case of mechanical dehydration processing, dewatering efficiency is high, and it is possible to further reduce the moisture content of sludge.

  In the electroosmotic dehydration apparatus of Patent Document 1, sludge is sandwiched between an endlessly rotating lower filter cloth belt (cathode) and an endlessly rotating upper filter cloth belt, and these filter cloth belts are sandwiched from above and below by electrodes. Pressure and electroosmosis dehydration treatment.

  The electroosmotic dewatering device of Patent Document 2 is configured such that an electrode drum as an anode is disposed separately from the upper press belt, and the upper and lower belts are clamped by this electrode drum.

  The electroosmotic dewatering device of Patent Document 3 supplies sludge onto a conveyor belt that rotates endlessly, and sandwiches a hydrated material between a cathode plate below the conveyor belt and an anode unit above the conveyor belt. The electroosmosis dehydration is performed by passing an electric current. A plurality of anode units are arranged in the conveyor moving direction. A horizontal anode plate is installed on the bottom surface of each anode unit. The anode plate can be pushed down by an air cylinder and can be pulled up by a spring. The conveyor moves the hydrated material by one span (anode unit installation interval) with the anode plate raised.

4-13003 JP-A-6-1554797 WO2007 / 143840

  In the electroosmosis dehydrator of Patent Document 3, the FIG. As shown in FIG. 5, the anode plate is fixed to the lower surface of the insulating plate, and this insulating plate is suspended from the upper surface plate (metal plate) by a spring. An air cylinder is disposed between the upper surface plate and the insulating plate, and the insulating plate is pushed downward by extending the air cylinder.

  In Patent Document 3, the anode plate is configured to move up and down while maintaining a horizontal state. Therefore, when sludge S is supplied unevenly in the width direction of the conveyor belt as shown in FIG. 4A described later, a situation in which a part of the anode plate does not contact the sludge S may occur. In the portion where the anode plate does not contact, the electroosmotic dehydration efficiency of the sludge is low.

  The present invention relates to an electroosmotic dehydration apparatus in which an electrode plate is pressed from the upper surface to an object to be processed on the upper surface side of a conveyor belt, and the object to be processed is unevenly distributed in the width direction of the conveyor belt. It is an object of the present invention to provide an electroosmotic dehydration apparatus capable of performing electroosmotic dehydration efficiently by bringing an electrode plate into close contact with the entire top surface of an object to be processed even when supplied.

An electroosmotic dehydration apparatus according to the present invention (Claim 1) includes an electrode disposed opposite to each other, an energizing means for energizing between the opposed electrodes, a filter medium disposed between the opposed electrodes, and one of the filter medium and In the electroosmotic dehydrating apparatus having a clamping means for clamping the water to be treated between the electrodes, the filter medium is a conveyor belt made of filter cloth, and is arranged to be endlessly rotatable, and the upper surface side is conveyed. The lower surface is a return side, a cathode is disposed below the conveyor side of the conveyor belt, an anode plate is disposed above the conveyor side of the conveyor belt, and the anode A plurality of plates are arranged in the longitudinal direction of the conveyor belt, the anode plate is fixed to the lower surface of the electrically insulating board, and the periphery of the anode plate is more than the periphery of the board. are retracted to the center side of the Banthai, 該盤body tiltably der The clamping means is intended to press the該盤body downwardly at its lower end, the lower end of該挟pressure means that it is linked to or tilt abuts against the upper surface of the該盤body It is a feature.

The electroosmotic dehydration apparatus according to claim 2 is the electroosmosis dehydrator according to claim 1, wherein side walls are provided upright on both sides of the conveyor belt on the conveying side, and the plate body and the anode plate are disposed between the side walls. The peripheral edge of the anode plate is set back from the peripheral edge of the disk body by 0.5 to 5 mm toward the center side of the disk body .

  In the electroosmotic dehydration apparatus of the present invention, the electrode plate overlapping from above on the object to be processed on the conveyor belt can be tilted. For this reason, even when workpieces are supplied unevenly in the width direction of the conveyor belt, the electrode plate tilts, the electrode plate adheres to the entire top surface of the sludge, and the workpiece is uniformly electro-osmotic dehydrated. can do.

It is a schematic longitudinal cross-sectional view of the electroosmosis dehydration apparatus which concerns on embodiment. It is a schematic longitudinal cross-sectional view of the electroosmosis dehydration apparatus which concerns on embodiment. It is detail drawing of the III-III line cross section of FIG. It is sectional drawing which shows the press condition of the sludge by an anode unit. (A) The figure is a block diagram of the air cylinder arrangement | positioning part of the electroosmosis dehydration apparatus which concerns on another embodiment, (b) A figure is the BB sectional drawing of (a) figure.

  Hereinafter, embodiments will be described with reference to the drawings. 1 and 2 are longitudinal sectional views taken along the longitudinal direction (belt moving direction) of the electroosmotic dehydrator according to the embodiment, and FIG. 3 is taken along the line III-III in FIG. 1 (a). Cross-sectional views and FIG. 4 are schematic cross-sectional views (cross-sectional views in the direction perpendicular to the longitudinal direction) showing the tilting situation of the anode. FIG. 1 shows the state of the dehydration process, and FIG. 2 shows the state of the belt feeding process of the electroosmosis dehydrator.

  A conveyor belt 1 made of filter cloth is stretched between the rollers 2 and 3 in an endless manner, and can be rotated endlessly.

  The upper surface side of the conveyor belt 1 is a conveyance side, and the lower surface side is a return side. A plate-like cathode 4 is disposed on the lower surface of the conveyor belt 1 on the conveyance side. The cathode 4 is a plate-like member made of a conductive material such as metal and has a large number of holes penetrating in the vertical direction. The cathode 4 extends from the immediate vicinity of the roller 2 to the immediate vicinity of the roller 3.

  As shown in FIG. 3, the cathode 4 is supported and fixed to a bracket 39 projecting from the lower rail angle 38 of the machine frame 30. The conveying side of the conveyor belt 1 slides on the upper surface of the cathode 4. The lower rail angle 38 is extended in the conveying direction of the conveyor belt 1.

  A hopper 5 is provided so as to supply water to be treated (sludge S in this embodiment) to the upstream portion in the transport direction of the upper surface (conveyance unit) of the conveyor belt 1.

  A tray 6 is provided under the cathode 4 to receive the filtrate falling through the hole of the cathode 4.

  The filtrate collected in the tray 6 is sent to the water treatment facility via the pipe 7, but a part of the filtrate may be added to the sludge in the hopper 5.

  Anode units 21, 22, 23, 24, and 25 are installed above the conveyor unit of the conveyor belt 1. As shown in FIG. 3, side wall plates 20 are erected on both sides of the conveyor unit of the conveyor belt 1 so that sludge on the conveyor belt 1 does not protrude sideways. The anode units 21 to 25 are disposed between the side wall plates 20 and 20. The side wall plate 20 is supported and fixed to the bracket 39.

  A beam 31 is horizontally installed above each anode unit 21 to 25. The beam 31 constitutes a part of the machine frame 30 and extends in the width direction of the conveyor belt 1.

  In this embodiment, five anode units 21 to 25 are arranged in the conveyor belt conveying direction, but the present invention is not limited to this. Usually, about 2 to 5 anode units may be arranged in the conveyor belt conveyance direction.

  As shown in FIG. 3, each of the anode units 21 to 25 is interposed between the electrically insulating board 32, the anode plate 33 fixed to the lower surface of the board 32, and the beam 31 and the board 32. The air cylinder 34 and the tension coil spring 35 are provided. The upper end of the cylinder portion 34 a of the air cylinder 34 is fixed to the beam 31, and the lower end of the piston rod 34 b is in contact with the upper surface of the plate body 32. The lower end of the piston rod 34 b is merely in contact with the upper surface of the board body 32 and is not connected to the board body 32. In FIG. 3, the lower end of the piston rod 34 b is a flat surface, but a hemispherical shape is preferable because the plate body 32 and the anode plate 33 are more easily tilted. The number of air cylinders 34 may be one or more.

  When air is supplied into the air cylinder 34, the piston rod 34b moves downward, and the plate body 32 and the anode plate 33 are pushed and moved downward. When air is discharged from the air cylinder 34, the plate body 32 and the anode plate 33 are pulled up and lifted by the tensile force of the coil spring 35.

  It is preferable that the periphery of the anode plate 33 recedes from the periphery of the disc body 32 to the center side of the disc body 32 by about 0.5 to 5 mm, particularly about 1 to 3 mm. This is because the anode plate 33 is prevented from coming into contact with the side wall plate 20 or the anode plate 33 of the adjacent anode unit even when the plate body 32 is tilted, and stray current and leakage are prevented. By retreating the edge of the anode plate 33 in this manner, water vapor is easily diffused from the gap between the anode plate 33 and the side wall plate 20 and between the anodes 33.

  A direct current is supplied to the anode plate 33 of each of the anode units 21 to 25 from a DC power supply device (not shown) via a terminal (not shown) provided on the panel body 32.

  In order to perform the sludge dewatering process by the electroosmotic dewatering device configured as described above, the sludge S supplied into the hopper 5 is fed onto the conveyor belt 1 and a direct current is applied to each of the anode units 21 to 25. Then, air is supplied to the air cylinders of the anode units 21 to 25, and the sludge is pressed from above by the anode plates 33 of the anode units 21 to 25.

  The voltage is applied so that the anode units 21 to 25 are positive and the cathode plate 4 is negative. Applying the same voltage to each of the anode units 21 to 25 is preferable from the viewpoint of facilitating operation management of the apparatus. However, the voltage may be increased or decreased on the downstream side in the transport direction. May be. Further, energization control may be performed so that the current values of the anode units are the same.

  The air of the same pressure may be supplied to the air cylinders of the anode units 21 to 25, and the supply air pressure may be increased or decreased as the anode unit on the downstream side.

  As described above, the current is passed between the anode units 21 to 25 and the cathode plate 4 and the sludge is pressed by the anode plate 33 of the anode units 21 to 25, whereby the sludge is electroosmotic dehydrated. Then, the dehydrated filtrate passes through the conveyor belt 1, passes through the holes of the cathode plate 4, and falls on the tray 6. When a part of the filtrate is supplied into the hopper 5, the electrical conductivity of the sludge to be treated is increased, and the electrical conductivity of the sludge between the anode units 21 to 25 and the cathode plate 4 is increased. Becomes higher and the dehydrating property is improved. Thereby, the moisture content of the dewatered sludge obtained becomes low.

  As shown in FIG. 1, when the anode units 21 to 25 are energized and the sludge is pressed by the anode units 21 to 25, the conveyor belt 1 is stopped. After pressing and energizing for a predetermined time by the anode units 21 to 25, air is discharged from the air cylinders of the anode units 21 to 25, and the anode plate 33 is raised by the tensile force of the spring 35. And the conveyor belt 1 is moved only 1 pitch of the arrangement pitch of the anode units 21-25. Thereby, the sludge located on the lower side of the anode unit 25 is sent out as dehydrated sludge, and the sludge located on the lower side of each of the anode units 21 to 24 is each one stage downstream of the anode units 22 to Move to the bottom of 25. Further, non-dehydrated sludge is introduced from the hopper 5 to the lower side of the anode unit 21. Next, the anode plate 33 of each anode unit 21 to 25 is pushed down and energized between each anode unit 21 to 25 and the cathode 4 to perform electroosmotic dehydration treatment of sludge. Thereafter, the sludge is electroosmotic dehydrated by repeating this process.

  In this embodiment, the disk body 32 to which the anode plate 33 is fixed is suspended by a spring 35, and the lower end of the piston rod 34b simply presses the disk body 32 from above. For this reason, the board body 32 and the anode plate 33 can be tilted. As a result, when the sludge is supplied unevenly in the width direction on the conveyor belt 1, for example, a large amount of sludge is supplied on the left side as shown in FIG. When a small amount is supplied, the board 32 tilts in the direction of the arrow θ as shown in FIG. 4 (b), the anode plate 33 adheres to the entire upper surface of the sludge S, and the entire sludge S is uniformly electroosmotic. Dehydrated.

  When the anode plate cannot be tilted as in the prior art, the anode plate 33 does not come into contact with the sludge S on the right side of FIG. The osmotic dehydration efficiency is lowered.

  In the above embodiment, the lower end of the piston rod 34b is not connected to the disk body 32, and the disk body 32 is pushed downward by the piston rod 34b. However, as shown in FIGS. 5 (a) and 5 (b). The lower end of the piston rod 34b may be connected to the board 32 so that the board 32 can tilt.

  In FIG. 5, a pair of brackets 41 is fixed on the upper surface of the board 32, and the lower end of the piston rod 34b is rotatably connected to the bracket 41 by a connecting shaft rod 42. The cylinder portion 34 a of the air cylinder 34 is rotatably connected to a pair of brackets 45 fixed to the lower surface of the beam 31 by a connecting shaft rod 46. The axial center line direction of each connecting shaft rod 42, 46 is the longitudinal direction of the conveyor belt 1.

  Thus, the air cylinder 34 can swing with the connecting shaft rod 46 as a fulcrum, and the disk body 32 can rotate with respect to the piston rod 34b. Therefore, when the supply amount of the sludge S becomes uneven in the width direction of the conveyor belt 1 as shown in FIG. 4 (a), the disc body 32 can be tilted as shown in FIG. 4 (b). Therefore, also according to this embodiment, the anode plate 33 is in close contact with the entire top surface of the sludge S, and the sludge S can be efficiently subjected to electroosmotic dehydration.

  In FIG. 5, the axial direction of the connecting shaft rod is the conveyor belt longitudinal direction, but a connecting shaft rod whose axial center direction is the conveyor belt width direction is further added, and the plate body 32 can be tilted in all directions. You may comprise. A universal joint such as a ball joint may be used instead of the connection by the shaft rod.

  In the case of FIG. 5, the air cylinder may be of a reciprocating type, and the board body 32 may be raised by the lifting force of the air cylinder. In this way, the spring 35 can be omitted. However, in this case as well, the spring 35 may be installed so that the rise of the plate body 32 is assisted by the spring 35.

  The above embodiment is an example of the present invention, and the present invention may be other than the above. For example, a lifting device other than an air cylinder may be used. Further, the connecting mechanism between the lifting device such as an air cylinder and the board is not limited to the illustrated one. The cathode plate may be divided for each anode unit.

DESCRIPTION OF SYMBOLS 1 Conveyor belt 2, 3 Roller 4 Cathode 5 Hopper 6 Tray 8 Storage tank 9 Pump 20 Side wall plate 21-25 Anode unit 32 Disc body 33 Anode plate 34 Air cylinder 35 Tensile coil spring

Claims (2)

Oppositely arranged electrodes;
Energizing means for energizing between the opposing electrodes;
A filter medium disposed between the opposing electrodes;
In an electroosmotic dehydration apparatus having clamping means for clamping the water to be treated between the filter medium and one electrode,
The filter medium is a conveyor belt made of filter cloth, is arranged to be endlessly rotatable, the upper surface side is the transport side, the lower surface side is the return side,
A cathode is disposed below the conveyor side of the conveyor belt, and an anode plate is disposed above the conveyor belt on the conveyor side;
A plurality of the anode plates are arranged in the longitudinal direction of the conveyor belt,
The anode plate is fixed to the lower surface of the electrically insulating board, and the periphery of the anode plate recedes toward the center of the board from the periphery of the board,
The board is tiltable;
The clamping means presses the board downward at its lower end,
An electroosmotic dehydration apparatus characterized in that the lower end of the pinching means is in contact with or tiltable with respect to the upper surface of the board. In claim 1, side wall plates are erected on both sides of the conveyor belt on the conveying side,
The board and the anode plate are disposed between the side wall plates,
The electroosmotic dehydration apparatus according to claim 1, wherein a peripheral edge of the anode plate is receded by 0.5 to 5 mm toward a central side of the board body from a peripheral edge of the board body.

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