JP4294523B2 - Sludge concentrator - Google Patents

Description

  The present invention relates to an apparatus for concentrating sludge.

  When treating industrial wastewater or domestic wastewater, a coagulation reactor, a concentrator and a screw press are connected in sequence. Sludge and a flocculant are supplied and mixed in the agglomeration reaction tank, and the sludge is agglomerated to generate flocs in the sludge. Aggregated sludge is supplied to a concentrator and separated by gravity to increase the concentration. The concentrated sludge is supplied to a screw press, and the liquid is separated mainly by pressing to make a dehydrated cake.

  The concentrator is a gravity concentrator, and as disclosed in Patent Document 1, a liquid-permeable sludge flow passage in which sludge flows down and concentrates is provided obliquely forward and downward. The sludge lower passage has the rear upper end as an inlet and the front lower end as an outlet. The outlet of the coagulation reaction tank is connected to the inlet of the sludge flow passage. The outlet of the sludge down passage is connected to the inlet of the screw press.

  The sludge flow passage has a cross-sectional shape of a groove and a bottom plate that is a liquid-permeable screen plate. A liquid chamber for collecting and discharging the liquid flowing down from the permeation holes of the liquid permeable bottom plate is provided below the sludge flow passage. On the sludge flow passage, a flow rate control device that also functions as a sweeping and cleaning device that sweeps the liquid-permeable bottom plate with a brush and controls the flow rate of sludge with a damming plate is provided. In addition, a cleaning device is provided that sprays cleaning water on a liquid-permeable bottom plate at set time intervals.

Japanese Patent No. 2934179

  However, the sludge supplied from the agglomeration reaction tank to the concentrator may vary in agglomeration state. When the concentration state of the sludge supplied to the inlet of the concentrator deteriorates, the performance of gravity concentration decreases, and the moisture content of the sludge supplied to the screw press from the outlet increases. Then, the dehydrated cake flowing out from the screw press has a high moisture content.

  In the concentrator, it is desirable that the moisture content of the sludge flowing out from the outlet does not exceed the maximum allowable value even if the state of aggregation of the sludge flowing into the inlet deteriorates.

  1) When observed in detail, the coagulant supplied to the coagulation reaction tank is maintained constant, but the concentration and flow rate of the sludge supplied to the coagulation reaction tank may fluctuate. If the amount of the flocculant relative to the solids in the sludge becomes too small, the sludge becomes insufficiently flocculated. Then, in the concentrator, it becomes difficult to separate the liquid from the sludge, and the gravity concentration performance decreases. Conversely, when the amount of the flocculant relative to the solid matter in the sludge becomes excessive, the viscosity of the sludge increases. Then, in the concentrator, the liquid-permeable sludge flow passage is likely to be clogged, and the gravity concentration performance is lowered.

  In addition, sludge is generally aerobic when it is fresh immediately after generation and easily aggregates. However, when the elapsed time after generation becomes long and old, it becomes anaerobic and hardly aggregates. The sludge supplied to the agglomeration reaction tank may fluctuate with ease. When sludge that is difficult to aggregate is supplied to the agglomeration reaction tank, the concentrator is supplied with sludge that is insufficiently aggregated, and the gravity concentration performance decreases.

  2) The present inventor has discovered that when weak pressing is applied to gravity-concentrated sludge, the sludge is concentrated by extracting the liquid. The term “weak pressing” means “weaker than pressing for sludge dewatering in a screw press”.

  It was also found that when a small amount of flocculant is added again to the sludge that has been concentrated by gravity with the addition of the flocculant, flocs are generated again to aggregate and become concentrated. The “small amount of flocculant” means “less than the amount of flocculant added to the sludge before gravity concentration”.

1) A sludge concentrator with an auxiliary concentration mechanism connected to a gravity concentrator,
A gravity concentrator is a concentrator in which agglomerated sludge added with a flocculant flows through a liquid-permeable passage and is concentrated by gravity.
The auxiliary concentrating mechanism includes a U-shaped cross-sectional liquid-permeable transfer concentrating passage fitted with a screw shaft, a drive device that rotates the screw shaft, an inlet and an outlet provided in the transfer concentrating passage, and an inlet of the transfer concentrating passage. Connected to the outlet of the gravity concentrator, and configured to transfer the sludge flowing into the inlet of the transfer concentration passage to the outlet of the transfer concentration passage by the rotation of the screw shaft,
The outlet side portion of the transfer concentration passage is made into a liquid-impermeable cylindrical shape, and a resistor that provides outflow resistance is provided at the outlet of the transfer concentration passage, and when sludge is transferred to the outlet side of the transfer concentration passage, the sludge is compressed. In addition, the composition was concentrated.

2) In the above sludge concentrator,
A device for adding a flocculant to the sludge flowing into the auxiliary concentration mechanism from the gravity concentrator was provided, and the sludge was reaggregated by the auxiliary concentration mechanism.

3) In the above sludge concentrator,
The auxiliary concentrating mechanism is provided with a device that rotates the screw shaft every set time to intermittently operate, and is configured to transfer the sludge in a state where the transfer concentrating passage is filled.

4) In the above sludge concentrator,
The auxiliary concentration mechanism has a configuration in which a brush is attached to the spiral blade of the screw shaft, and when the screw shaft rotates, the transfer concentration passage is swept and cleaned by the brush.

  In the sludge concentrating device, the coagulated sludge is concentrated by gravity with a gravity concentrator, and then weakly compressed by an auxiliary concentration mechanism and concentrated.

  Even if the coagulation state of the sludge supplied to the gravity concentrator deteriorates and the performance of gravity concentration deteriorates, the sludge is concentrated by weak squeezing by the auxiliary concentration mechanism after gravity concentration, and the gravity concentration is insufficient. Minutes are supplemented by squeeze concentration. The sludge flowing out from the auxiliary concentration mechanism can maintain the moisture content below the maximum allowable value. When the gravity concentration performance does not decrease, the concentration rate is increased by gravity concentration and compression concentration. The sludge flowing out of the auxiliary concentration mechanism can have a moisture content much lower than the maximum allowable value.

  In the auxiliary concentration mechanism, when sludge is re-agglomerated by adding a flocculant, the sludge is easily concentrated by re-aggregation. Concentration performance increases.

  In the auxiliary concentration mechanism, when the sludge is transferred in a state where the transfer concentration passage is filled, the sludge is easily squeezed in the transfer concentration passage. Concentration performance increases.

  In the auxiliary concentrating mechanism, when the screw shaft rotates, when the transfer concentrating passage is swept and cleaned with a brush, the liquid permeable transport concentrating passage is not easily clogged. Concentration performance increases.

[First example (see FIGS. 1 to 4)]
As shown in FIG. 1, the industrial wastewater treatment apparatus sequentially connects the coagulation reaction tank 1, the sludge concentration apparatuses 11 and 21, and the screw press 41.

〔Constitution〕
The agglomeration reaction tank 1 is connected to a sludge tank 2 between a sludge supply passage 3 with a pump and a flocculant supply passage 4 and is provided with a stirring device 5. In the sludge tank 2, the sludge that flows in from the sludge supply passage 3 and the flocculant that flows in from the flocculant supply passage 4 are stirred and mixed by the stirring device 5, and agglomeration reaction is performed to generate flocs in the sludge.

As shown in FIG. 1, the sludge concentrating apparatuses 11 and 21 of this example connect an auxiliary concentrating mechanism 21 to the gravity concentrator 11.
The gravity concentrator 11 is provided with a liquid-permeable sludge flow passage 12 that sludges flow down and is concentrated obliquely forward and downward. The sludge lower passage 12 has a rear upper end as an inlet and a front lower end as an outlet. An outlet of the sludge tank 2 of the agglomeration reaction tank 1 is connected to the inlet of the sludge lower passage 12. The outlet of the sludge lower passage 12 is connected to the inlet of the auxiliary concentration mechanism 21.

  As shown in FIGS. 1 and 2, the sludge lower passage 12 has a cross-sectional shape of a groove and a bottom plate that is a liquid-permeable screen plate. Below the sludge flow passage 12, a liquid chamber 13 for collecting and discharging the liquid flowing down from the permeation holes of the liquid permeable bottom plate is provided. A device that sweeps the liquid permeable bottom plate with a brush and controls the speed at which the sludge flows down with a damming plate is provided on the sludge lower passage 12.

  The flow rate control device also serving as a sweeping cleaning device is provided with a drive shaft 14 and a driven shaft 15 along the left-right direction in the passage crossing direction on the inlet side and the outlet side on the sludge flow passage 12. The drive shaft 14 is connected to the electric motor 16 by a transmission mechanism. The drive shaft 14 and the driven shaft 15 each have a chain wheel 17 fixed at the left and right positions. An endless chain 18 is stretched around the left wheel 17 of the drive shaft 14 and the driven shaft 15. Further, an endless chain 18 is also passed over the right side wheel 17 of the drive shaft 14 and the driven shaft 15. A base end side of a baffle plate 19 is attached to the left and right chains 18 and is hung in the left-right direction. The dam plate 19 protrudes the brush 20 on the tip side. On the outer peripheral side of the chains 18 on both sides, a baffle plate 19 with a brush 20 protrudes outward in parallel at equal intervals. While the baffle plate 19 with the brush 20 is positioned on the lower side of the chain 18, it fits in the sludge flow lower passage 12 along the passage crossing direction, and the brush 20 protruding to the front end side of the baffle plate 19 is attached to the sludge flow lower passage 12. Touch the bottom plate.

  When the electric motor 16 is driven, the dam plate 19 with the brush 20 reaches the lower side of the chain 18 around the drive shaft 14, enters the sludge flow passage 12, and fits into the sludge flow passage 12. The damming plate 19 is lowered into the sludge flow passage 12 at a set speed while the brush 20 sweeps the bottom plate in a state of being fitted to the sludge flow passage 12. When the baffle plate 19 with the brush 20 reaches the outlet of the sludge flow passage 12, the sludge flow passage 12 comes out of the sludge flow passage 12, travels around the driven shaft 15, and reaches the upper side of the chain 18.

  The sludge flowing down the sludge flow passage 12 flows down while being blocked by the baffle plate 19 with the brush 20 that moves down the sludge flow passage 12 at a set speed. Compared to the case of natural flow, the flow rate is slower, the concentration time for staying on the sludge flow passage 12 is longer, and the concentration rate is higher. Moreover, the sludge lower passage 12 is swept with the brush 20 and is not easily clogged.

  Although not shown in the figure, a cleaning device for injecting a set amount of cleaning water at a set time is provided on the sludge lower passage 12.

  The auxiliary concentration mechanism 21 is a screw conveyor having a concentration function. As shown in FIG. 1, the liquid chamber 13 of the gravity concentrator 11 is formed in a shape protruding forward on the lower side of the outlet of the sludge flow passage 12. As shown in FIGS. 1 and 3, a liquid permeable transfer concentration passage 22 is formed in the projecting front portion of the liquid chamber 13 along the transverse direction and the left-right direction of the sludge lower passage 12. The transfer concentration passage 22 is formed by bending a liquid-permeable screen plate into a U-shaped cross-sectional shape, and has an open upper surface as an inlet, and an outlet of the sludge flow passage 12 is connected to the inlet. The sludge flows into the transfer concentration passage 22 immediately after flowing down the sludge flow passage 12. The liquid flowing down from the permeation hole of the transfer concentration passage 22 flows into the liquid chamber 13.

  As shown in FIG. 3, the transfer concentration passage 22 having a U-shaped cross section is fitted with a screw shaft 23. The screw shaft 23 has both left and right ends passing through the left and right side walls of the liquid chamber 13 and bearings, and an electric motor 24 of the driving device is connected to one end protruding from the liquid chamber 13. The spiral blade 25 of the screw shaft 23 has the spiral direction reversed between the left half and the right half. When the motor 24 is driven to rotate the screw shaft 23 in one direction, the sludge in the left half of the transfer concentration passage 22 is transferred to the right and the sludge in the right half is transferred to the left. The sludge is collected in the center from both the left and right sides of the transfer concentration passage 22. An outlet is opened on the lower surface of the center of the transport and concentration passage 22, the upper end of the sludge outlet passage 26 is connected to this outlet, and the lower end of the sludge outlet passage 26 protrudes below the liquid chamber 13. The sludge falling from the outlet of the transfer concentration passage 22 flows out of the liquid chamber 13 through the sludge outlet passage 26.

  As shown in FIG. 3, the transfer concentration passage 22 is provided with a partition plate 27 at the center position of the passage to partition the left half right transfer portion and the right half left transfer portion, and the central lower surface outlet is provided. Divided into an exit for the right transfer section and an exit for the left transfer section.

  Further, the right transfer portion outlet and the left transfer portion outlet of the transfer concentration passage 22 are each provided with a valve plate 28 for increasing or decreasing the opening area. As shown in FIG. 4, the valve plate 28 is curved in a semi-cylindrical shape, and is fitted to the semi-cylindrical lower surface of the transfer concentration passage 22. Rails 29 are provided on both sides of the transfer concentrating passage 22, and grooves are provided on the upper ends of both sides of the valve plate 28, and the rails 29 and grooves are fitted so that the valve plate 28 can be moved along the transfer concentrating passage 22. ing. The semi-cylindrical valve plate 28 closes the permeation hole in the lower semi-cylindrical shape of the transfer concentrating passage 22 to which the valve plate 28 is fitted, and closes the right transfer portion outlet or the left transfer portion outlet of the transfer concentrating passage 22. To do. The valve plate 28 is a resistor that gives outflow resistance to the outlet of the transfer concentration passage 22. The position of the valve plate 28 is changed to increase or decrease the outflow resistance.

  As shown in FIGS. 3 and 4, the transfer concentration passage 22 is attached to the upper half of the central portion of the spiral blade 25 of the screw shaft 23 with a semi-cylindrical cover plate 30, and the upper part on the outlet side of the right transfer unit. And the upper part on the exit side of the left transfer part is closed.

  That is, the right transfer portion and the left transfer portion of the transfer concentration passage 22 are respectively closed at the outlet side portion by a liquid impervious end with the upper cover plate 30, the lower valve plate 28 and the partition plate 27. When the sludge is transferred to the outlet side, the sludge is compressed and concentrated.

  On the cover plate 30, a guide slope 31 that distributes sludge falling on the cover plate 30 to the right and left right transfer unit inlets and the left transfer unit inlets is provided.

  The amount of sludge flowing from the gravity concentrator 11 into the auxiliary concentration mechanism 21 is smaller than the transfer amount of the transfer concentration passage 22 of the auxiliary concentration mechanism 21. When the transfer mechanism of the transfer concentration passage 22 is continuously operated in the same manner as the gravity concentrator 11, the sludge is transferred in a state where the transfer concentration passage 22 is not filled. It is hard to be squeezed. Therefore, an operation control device is provided that intermittently operates the transfer mechanism of the transfer concentration passage 22 by rotating the screw shaft 23 by the electric motor 24 for each set time. The sludge is transferred in a state where the right and left transfer parts of the transfer concentration passage 22 are filled. Easy to be squeezed.

  As shown in FIG. 4, the spiral blade 25 of the screw shaft 23 is attached with a brush 32 protruding outward on the outer peripheral edge. When the screw shaft 23 rotates, the transfer concentration passage 22 is swept by the brush 32. Hard to clog.

  As shown in FIG. 3, a flocculant spray pipe 33 is disposed along the transfer concentration passage 22 above the transfer concentration passage 22, and a sludge reaggregation device adds the flocculant to the sludge flowing into the transfer concentration passage 22. Is provided. The sludge is re-agglomerated in the transfer concentration passage 22. It becomes easy to concentrate.

  As shown in FIG. 1, the screw press 41 has a screw shaft 43 fitted to a liquid permeable cylinder 42 disposed horizontally. One end of the screw shaft 43 protrudes from the end of the liquid permeable cylinder 42 and is connected to the electric motor 44 by a transmission mechanism.

  A spiral transfer compression passage 45 is formed between the liquid permeable cylinder 42 and the bladed portion of the screw shaft 43. The transfer compression passage 45 has a cross-sectional area that decreases from the inlet side toward the outlet side. A sludge outlet passage 26 of the sludge concentrator is connected to the inlet of the transfer compression passage 45.

  A cylindrical or annular compression chamber 46 is formed between the liquid-permeable cylinder 42 and the bladeless portion of the screw shaft 43. The compression chamber 46 has an outlet of the transfer compression passage 45 as an inlet and an opening end of the liquid permeable cylinder 42 as an outlet. A resistor 47 is provided at the outlet of the compression chamber 46 to give outflow resistance.

  A liquid chamber 48 for collecting and discharging the liquid flowing down from the permeation hole of the liquid permeable cylinder 42 is provided under the liquid permeable cylinder 42. Under the outlet of the compression chamber 46, a dehydrated cake dropping passage 49 is provided.

[Operation]
In the flocculation reaction tank 1, sludge and a flocculant are supplied to the sludge tank 2. The sludge is added with a flocculant to cause a coagulation reaction. Aggregated sludge flows out from the outlet of the sludge tank 2 and flows into the sludge concentrators 11 and 21. In the sludge concentrators 11 and 21, the sludge that has flowed from the agglomeration reaction tank 1 sequentially passes through the gravity concentrator 11 and the auxiliary concentration mechanism 21.

  In the gravity concentrator 11, the sludge flows into the inlet of the sludge flow passage 12, and flows down at a set speed while being dammed through the sludge flow passage 12 by a baffle plate 19 with a brush 20. It is concentrated by gravity. The concentrated sludge flows out from the outlet of the sludge down passage 12 and flows into the auxiliary concentration mechanism 21. In the auxiliary concentration mechanism 21, the sludge flows from the outlet of the sludge flow passage 12 to the inlet of the transfer concentration passage 22.

  When the sludge flowing into the transfer and concentration passage 22 is re-agglomerated, the sludge re-aggregation device is operated, and the flocculant is sprayed from the flocculant spray pipe 33 to the entrance of the transfer and concentration passage 22, so that the sludge in the transfer and concentration passage 22 is formed. Add flocculant. The sludge is re-agglomerated in the transfer concentration passage 22.

  The sludge that has fallen into the liquid-permeable transfer concentration passage 22 is first concentrated by gravity. Next, when the transfer concentration passage 22 is filled with sludge, the screw shaft 23 rotates and the transfer mechanism of the transfer concentration passage 22 is operated. Then, the rightward transfer unit and the leftward transfer unit of the transfer concentration passage 22 transfer the sludge to the outlet side in a state where the transfer concentration passage 22 is filled. The sludge in the right transfer unit and the left transfer unit is pressed into the liquid non-permeable outlet side portions 27, 28, and 30, respectively, and compressed and concentrated. The concentrated sludge flows into the screw press 41 via the sludge outlet channel 26 from the right transfer section outlet and the left transfer section outlet, respectively.

  In the screw press 41, the sludge flows down to the inlet end of the transfer compression passage 45 and is gravity dehydrated. The sludge is transferred to the outlet side through the transfer compression passage 45 by the rotation of the screw shaft 43, and is strongly compressed and compressed and dehydrated as it approaches the outlet of the transfer compression passage 45. Next, the sludge is pushed by the subsequent sludge, sent into the compression chamber 46, further compressed, and squeezed and dehydrated again. The sludge that has sequentially passed through the transfer compression passage 45 and the compression chamber 46 has a reduced moisture content, becomes a dehydrated cake, and is pushed out from the outlet of the compression chamber 46 while receiving resistance by the resistor 47. The dehydrated cake falls through the dehydrated cake dropping passage 49.

  An example is wastewater treatment in food factories. When the coagulation state of the sludge does not deteriorate in the coagulation reaction tank 1, the sludge has a water content of 99% when flowing into the gravity concentrator 11 from the coagulation reaction tank 1, and flows into the auxiliary concentration mechanism 21 from the gravity concentrator 11. When the water content is 94%. The concentration is increased from 1% to 6% by the gravity concentrator 11. The moisture content is 91% when flowing from the auxiliary concentration mechanism 21 into the screw press 41. The auxiliary concentration mechanism 21 increases the concentration from 6% to 9%.

  In the sludge concentrating apparatus of this example, as a result of connecting the auxiliary concentrating mechanism 21 to the gravity concentrator 11, when the sludge aggregation state does not deteriorate, the concentrated sludge has a moisture content that is reduced by 3%. The concentration is increased by 3%. Concentration rate increases. Even if the aggregation state of the sludge supplied to the gravity concentrator 11 deteriorates and the concentration performance of the gravity concentrator 11 decreases, the lack of concentration of the gravity concentrator 11 is supplemented by the concentration of the auxiliary concentration mechanism 21. The sludge flowing into the screw press 41 from the auxiliary concentration mechanism 21 can maintain the moisture content below the maximum allowable value.

[Second example (see FIG. 5)]
This example is an example in which the auxiliary concentration mechanism 21 of the sludge concentration apparatus in the first example is changed. The agglomeration reaction tank 1, the gravity concentrator 11 of the sludge concentrator and the screw press 41 are the same as those in the first example.

〔Constitution〕
The auxiliary concentration mechanism 51 of the sludge concentrating device of this example replaces the transfer concentration passage 22 of the first example for transferring the sludge from both ends to the center, and transfers and concentrates the sludge in one direction from one end to the other end. A passage 52 is provided.

  As in the first example, the liquid chamber 13 of the gravity concentrator 11 is formed in a shape projecting forward on the lower side of the outlet of the sludge flow passage 12. As shown in FIG. 5, a transfer concentration passage 52 is formed in the projecting front portion of the liquid chamber 13 along the transverse direction and the left-right direction of the sludge lower passage 12. The transfer concentrating passage 52 is formed by curving a screen plate into a U-shaped cross section, and has an open upper surface as an inlet, and the outlet of the sludge lowering passage 12 is connected to the inlet. The sludge flows down the sludge down passage 12 and flows into the transport concentration passage 52. The liquid that flows down from the permeation hole of the transfer concentration passage 52 flows into the liquid chamber 13.

  As shown in FIG. 5, the transfer concentration passage 52 having a U-shaped cross section is fitted with a screw shaft 53. One end of the screw shaft 53 is supported on the side wall of the liquid chamber 13, and an electric motor 54 of a driving device is connected to one end protruding from the liquid chamber 13. The spiral blade 55 of the screw shaft 53 has the same spiral direction from one end to the other end. When the electric motor 54 is driven to rotate the screw shaft 53 in one direction, the sludge in the transfer concentration passage 52 is transferred to the other end side opposite to the electric motor 54.

  The other end side of the transfer concentration passage 52 and the screw shaft 53 protrudes from the liquid chamber 13. The protrusion 56 on the other end side of the transfer concentration passage 52 is formed in a liquid-impermeable cylindrical shape, and has an open end as an outlet, and a sludge outlet passage 57 is connected to the outlet. The other end side of the screw shaft 53 penetrates the protruding portion 56 of the transfer concentration passage 52 and the sludge outlet passage 57 and is supported on the side wall of the sludge outlet passage 57. A valve plate 58 is attached to the bladeless portion of the screw shaft 53 so as to be movable along the screw shaft 53 in the sludge outlet passage 57. The valve plate 58 is a resistor that faces the outlet of the transfer concentration passage 52 and gives outflow resistance to the outlet of the transfer concentration passage 52. The position of the valve plate 58 is changed to increase or decrease the outflow resistance.

  That is, the liquid permeable transfer concentration passage 52 is configured such that the protrusion 56 on the outlet side portion is formed in a liquid non-permeable cylindrical shape, and when the sludge is transferred to the outlet side, the sludge is compressed and concentrated. ing.

  In FIG. 5, reference numeral 59 denotes a sloping guide slope for the sludge flowing from the sludge lower passage 12 into the transfer concentration passage 52.

  As in the first example, there is provided an operation control device that intermittently operates the transfer mechanism of the transfer concentration passage 52 by rotating the screw shaft 53 for a set time by the electric motor 54 for each set time. The sludge is transferred to the outlet side in a state where the transfer concentration passage 52 is filled. Easy to be squeezed.

  As in the first example, the spiral blade 55 of the screw shaft 53 is attached with a brush protruding outward on the outer peripheral edge. When the screw shaft 53 rotates, the transfer concentration passage 52 is swept with a brush. Hard to clog.

  As shown in FIG. 5, a flocculant spray pipe 60 is disposed along the transfer concentration passage 52 above the transfer concentration passage 52, and the sludge reflocculation device adds the flocculant to the sludge flowing into the transfer concentration passage 52. Is provided. The sludge is re-agglomerated in the transfer concentration passage 52. It becomes easy to concentrate.

[Operation]
In the sludge concentrators 11 and 51 of this example, the agglomerated sludge flowing in from the agglomeration reaction tank 1 sequentially passes through the gravity concentrator 11 and the auxiliary concentration mechanism 51 as in the first example. In the gravity concentrator 11, as in the first example, the sludge flows down the sludge flow passage 12, is concentrated by gravity, and flows into the auxiliary concentration mechanism 51.

  In the auxiliary concentration mechanism 51, when the sludge flowing into the transfer concentration passage 52 from the sludge flow passage 12 is re-agglomerated, the sludge re-aggregation device is operated, the flocculant is sprayed from the coagulant spray pipe 60, and the transfer concentration passage 22 is operated. Add flocculant to the sludge inside.

  The sludge that has fallen into the transfer concentration passage 52 is concentrated by gravity. When the transfer concentration passage 52 is filled with sludge, the screw shaft 53 rotates and the transfer mechanism of the transfer concentration passage 52 is operated. Then, the sludge is transferred to the outlet side in a state where the transfer concentration passage 52 is filled, and is pushed into the liquid non-permeable outlet side portion 56 and squeezed. It is pressed and concentrated. The concentrated sludge flows from the outlet of the transfer concentration passage 52 to the inlet of the screw press 41 through the sludge outlet passage 57.

  In the screw press 41, as in the first example, the sludge sequentially passes through the transfer compression passage 45 and the compression chamber 46, becomes a dehydrated cake, and falls through the dehydrated cake dropping passage 49.

  In the auxiliary concentration mechanism 51, the sludge outlet connected to the lower end of the sludge outlet passage 57 and the inlet of the screw press 41 is located not directly below the sludge outlet of the gravity concentrator 11 but on the side just below it. When the inlet of the screw press 41 cannot be disposed directly below the sludge outlet of the gravity concentrator 11 and is shifted to the side just below the auxiliary concentrating mechanism 51, the auxiliary concentrating mechanism 51 also serves as a transfer mechanism. Convenient.

  The present invention is used for the treatment of industrial wastewater and domestic wastewater.

1 is a schematic elevation view of an industrial wastewater treatment apparatus provided with a sludge concentration apparatus in a first example of an embodiment of the present invention. The schematic enlarged view which looked at the gravity concentration machine of the sludge concentration apparatus from the entrance side. FIG. 2 is a schematic enlarged elevation view of the auxiliary concentration mechanism of the sludge concentration apparatus as viewed from the right side of FIG. The partial schematic enlarged view of the AA line cross section of FIG. It is a schematic elevation view of the auxiliary concentration mechanism of the sludge concentration apparatus in the 2nd example of embodiment, and is a figure corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coagulation reaction tank 11, 21 Sludge concentrator 11, 51 Sludge concentrator 11 Gravity concentrator 12 of sludge concentrator 12 Sludge flow-down path 13 Liquid chamber 19 Damping plate 20 of drip speed control device used also as sweeping cleaner Flushing speed used as sweeper Brushes 21 and 51 of the control device Auxiliary concentration mechanism of the sludge concentration device, screw conveyors 22 and 52 having a concentration function, transfer and concentration passages 23 and 53, screw shafts 24 and 54, drive devices, electric motors 25 and 55, spiral blades 26 of the screw shaft, 57 Sludge outlet passages 27, 28, 30 Liquid-impermeable one-end-closed cylindrical outlet side portion 27 of the transfer concentration passage Partition plate 28, 58 Valve plate, resistor 29 Rail 30 Cover plate 31 Guide slope 32 Brush 33, 60 Sludge Coagulant spray pipe 41 of reaggregation device Screw press, sludge dehydrator 56 Protrusion of transfer concentration passage, liquid impermeability Cylindrical outlet section of the

Claims (4)

A concentration device in which an auxiliary concentration mechanism is connected to a gravity concentrator,
A gravity concentrator is a concentrator in which agglomerated sludge added with a flocculant flows through a liquid-permeable passage and is concentrated by gravity.
The auxiliary concentrating mechanism includes a U-shaped cross-sectional liquid-permeable transfer concentrating passage fitted with a screw shaft, a drive device that rotates the screw shaft, an inlet and an outlet provided in the transfer concentrating passage, and an inlet of the transfer concentrating passage. Connected to the outlet of the gravity concentrator, and configured to transfer the sludge flowing into the inlet of the transfer concentration passage to the outlet of the transfer concentration passage by the rotation of the screw shaft,
The outlet side portion of the transfer concentration passage is made into a liquid-impermeable cylindrical shape, and a resistor that provides outflow resistance is provided at the outlet of the transfer concentration passage, and when sludge is transferred to the outlet side of the transfer concentration passage, the sludge is compressed. In addition, the sludge concentrator is characterized in that it is configured to concentrate.   2. The sludge concentrator according to claim 1, wherein a device for adding a flocculant to sludge flowing into the auxiliary concentration mechanism from the gravity concentrator is provided, and the sludge is reaggregated by the auxiliary concentration mechanism.   The auxiliary concentrating mechanism is provided with a device for intermittent operation by rotating the screw shaft every set time, and configured to transfer the sludge in a state where the transfer concentrating passage is filled. Sludge concentrator.   The sludge concentrating device according to claim 1, 2 or 3, wherein the auxiliary concentrating mechanism is configured such that a brush is attached to a spiral blade of the screw shaft, and when the screw shaft rotates, the transfer concentrating passage is swept and cleaned by the brush. .

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