JP4487908B2 - Concentrator for sludge - Google Patents

Description

  The present invention relates to an improvement of a concentrating device for separating and concentrating a filtrate from agglomerated sludge generated with flocs such as sewage sludge and industrial wastewater.

  Conventionally, when a stock solution is squeezed or dehydrated using a screw press or a belt press, floc is granulated by supplying a flocculant to the stock solution having a low concentration, and a concentrator is used as a pretreatment operation. Is well known. Conventionally used concentrators include centrifugal concentrators and atmospheric pressure flotation concentrators. Centrifugal concentrators can be processed in large quantities, but because the processing is performed at high speed, the equipment power is increased. It is easy to wear due to high-speed rotation, and maintenance costs for consumables and the like are high. The atmospheric pressure levitation concentrator reduces the maintenance cost, but requires a long processing time. The concentrator main body is large and there are many incidental facilities, so the installation space becomes large.

  As a prior art in which a screen is formed on both sides of a conventional annular casing and a filtration chamber is formed inside, a rotatable screen is installed in the annular filtration chamber, and sludge is introduced from the annular peripheral wall of the filtration chamber. A rotary compression filter that compresses and dehydrates sludge by the rotational frictional force of the screen and discharges the cake from the annular peripheral wall is known, for example, as described in Patent Document 1. In addition, a screen is stretched in the annular filtration chamber, the blade is fixed to the drive shaft provided with the stock solution supply path, and the filtrate is separated by the press-fitting pressure of the stock solution and the rotational force of the blade. The patent applicant has also proposed a continuous squeezing and dewatering device that discharges slag, as described in Patent Document 2, for example. As a sludge concentrating device to be supplied to a conventional screw press or the like, a concentrating device in which a screen drum having spiral blades wound around a central portion of a cylindrical tank is also described in, for example, Patent Document 3. As proposed, the patent applicant has proposed.

JP 2001-113109 A (Claim 1, paragraph number 0014 to paragraph number 0017, FIG. 7) Japanese Patent No. 3548888 (Claim 1, FIG. 1 and FIG. 2) Japanese Utility Model Publication No. 8-10348 (Claim 1, FIG. 4)

  A conventional rotary compression filter that rotates the screen and the inner ring spacer at a low speed has the advantage of reducing energy consumption and noise. However, since the compression is performed by the rotational frictional force of the screen, the processing time becomes longer. In addition, since the conventional continuous dehydration device for rotating the blades separates the filtrate by the press-fitting pressure of the stock solution and the rotational force of the blades, the structure is simple and the installation area is reduced. Although the filtration efficiency is high and it is used at low speed operation, there is a problem of clogging of the screen for use in a concentrator. The concentrator with a screen drum with spiral blades wound around the center of a cylindrical tank allows high-pressure squeezing and dehydration in subsequent screw presses and belt presses, depending on the nature of the stock solution. There is a risk that clogging of the screen drum will not be resolved with just washing water. The present invention is a sludge and other concentrator that can improve the concentrating efficiency and eliminate clogging by applying the advantages of the conventional dewatering device having screens arranged on both sides of the conventional annular casing and the conventional concentrating device. provide.

  The gist of the concentrating device for sludge and the like according to the present invention is agglomeration in which a rotatable screen is provided on both sides of an annular casing to form a concentrating chamber inside, and the upper part of the casing expands in the rotating direction of the screen. A sludge supply port and a concentrated sludge discharge port at the bottom, and rotary blades that divide the concentrating chamber radially are arranged to rotate the screen and rotary blades at a different speed. In the vicinity of the part, the concentration by low concentration proceeds rapidly, but sludge can be supplied only by the filtrate separated from the supply port that expands in the rotation direction. The voids in the divided filter chamber divided by the rotating blades that increase as the concentration progresses are reduced, and the ineffective area of the screen can be reduced. The concentration concentration can be adjusted by adjusting the residence time of the concentrating chamber and the number of times of filter medium regeneration by adjusting the rotational speed of the rotary blade and the differential speed rotation of the screen, and high processing capacity can be obtained with a small filtration area. .

  A scraper is fixed to both sides of the blades of the rotating blades and brought into sliding contact with the inner peripheral surface of the screen, and a cleaning pipe is provided on the outer peripheral surface of the screen at the rear of the concentrated sludge discharge zone. The filter cake is scraped off with a scraper to always regenerate the filtration surface. And since wash water is sprayed on the screen which discharged | emitted the concentrated sludge of the concentrated sludge discharge zone, the residue adhering to a screen can be washed away, and the washing waste_water | drain which went inside can be mixed and discharged to a concentrated sludge. The residue does not stay inside the filtration hole of the screen, and the filtration area is not reduced.

  The invention of the present application is configured as described above, and the supply opening is greatly opened in consideration of the additional supply of water leakage, so that the ineffective area of the screen can be reduced. Since the filtration surface is regenerated from both sides of the screen by the scraper and the washing tube, the filtration surface is always regenerated, the filtration performance is not deteriorated by clogging, and the filtration area is not reduced. If the washing water pressure in the washing tube is increased, even the concentrated sludge remaining after being concentrated to a high concentration can be washed away from the screen.

  The concentration device for sludge and the like according to the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a cross-sectional view of the concentration device according to the present invention, and the concentration device 1 rotates on both sides of an annular casing 2. Free screens 3 and 3 are arranged, and a concentration chamber 4 is formed inside. The screen 3 is formed in a disk shape with a metal filter medium such as punching metal or wedge wire. Rotary blades 7 in which a plurality of flat blade plates 6... Are radially attached to blade rotation shafts 5 that pass through the center of the screen 3 and are disposed in the concentration chamber 4. Divided filter chambers 8 are formed by dividing the concentration chamber 4 equally. A rectangular supply port 9 is provided at the upper part of the casing 2 and a discharge port 10 for concentrated sludge is provided at the lower part thereof. The supply port 9 has a large opening in the rotation direction to widen the coagulated sludge supply zone A. It is. The supply port 9 considering the additional supply of water leakage is preferably set to 1/2 to 1/3 of the diameter of the screen 3. If the aggregated sludge supply zone A is widened, the amount of supplied sludge near the supply port 9 of the concentrating chamber 4 increases, and sludge is supplied by the amount of filtrate separated in the vicinity of the supply unit. The voids in the divided filter chamber 8 that increase with the progress of concentration are reduced, and the ineffective area of the screen 3 can be reduced.

  FIG. 2 is a perspective view of the concentrating device, in which a drive gear 12 is fitted on the screen drive shaft 11, and this drive gear 12 is meshed with the outer peripheral surface of the screen 3. While the screen 3 is in sliding contact with the side surface of the casing 2, the screen 3 and the rotary blade 7 are rotated in opposite directions. The concentration concentration can be adjusted by adjusting the residence time of the concentration chamber 4 and the number of times of filter medium regeneration by adjusting the number of rotations of the screen 3 and the rotary blade 7, and a high processing capacity can be obtained with a small filtration area. The screen 3 and the rotary blade 7 may be rotated by giving a speed difference in the same direction.

  FIG. 3 is a longitudinal sectional view of the concentrating chamber. The scraper 13 is fixed to both side surfaces of the blade 6 of the rotary blade 7 and is in sliding contact with the inner peripheral surface of the screen 3. The solid matter trapped on the filtration surface of the screen 3 is scraped off by the scraper 13. As shown in FIG. 2, a cleaning pipe 14 is disposed on the outer peripheral surface of the screen 3 at the rear portion of the concentrated sludge discharge zone B, and cleaning water is supplied to the outer peripheral surface of the screen 3 from which the concentrated sludge has been discharged from the discharge port 10. Since the spraying is performed, the washing water penetrating the filtration hole of the screen 3 ishes away the residue adhering to the filtration surface of the screen 3, and the washing drainage drained inside is mixed with the concentrated sludge and discharged. Filter cake does not stay on the filtration surface of the screen 3, and the filtration area is not reduced. Since the solid matter trapped on the filtration surface of the screen 3 is scraped off by the scraper 13 and the washing water is sprayed from the outer peripheral surface of the screen 3, the filtration surface is always regenerated and the filtration performance is not deteriorated due to clogging. . If the washing water pressure in the washing tube 14 is increased, the concentrated sludge that is concentrated to a high concentration and remains in the filter medium hole can be washed away from the screen 3.

  The concentration device for sludge and the like according to the present invention has a supply port for agglomerated sludge that opens largely in the rotational direction at the upper part of the casing, and a cleaning pipe is provided on the outer peripheral surface of the screen at the rear of the concentrated sludge discharge zone where the concentrated sludge is discharged. Since the screen and the rotating blades are rotated at a differential speed, the space between the divided filter chambers divided by the rotating blades is reduced, and the ineffective area of the screen can be reduced. Since the filtration surface is regenerated from both sides of the screen with the scraper and the washing water, the filtration surface is always regenerated, the filtration performance is not deteriorated due to clogging, and the filtration area is not reduced. Therefore, it is suitable as a concentrating device for coagulated sludge such as sewage sludge and industrial wastewater, and enables high-pressure squeezing and dehydration of a screw press or a belt press installed in the subsequent stage.

It is a cross-sectional view of a concentration device for sludge and the like according to the present invention. Similarly, it is a perspective view of a concentration apparatus. Similarly, it is a longitudinal sectional view of the concentrating device.

Explanation of symbols

2 Casing 3 Screen 4 Concentration chamber 6 Blade plate 7 Rotating blade 9 Supply port 10 Discharge port 13 Scraper 14 Washing tube B Concentrated sludge discharge zone

Claims (2)

  Rotating screens (3, 3) are arranged on both sides of the annular casing (2) to form a concentrating chamber (4) inside, and in the rotational direction of the screen (3) above the casing (2). The aggregated sludge supply port (9) to be expanded and the concentrated sludge discharge port (10) to the lower portion thereof are disposed, and the rotary blades (7) for radially dividing the concentration chamber (4) are disposed, An apparatus for concentrating sludge or the like, characterized in that the screen (3) and the rotating blade (7) are rotated at a differential speed.   A scraper (13, 13) is fixed to both side surfaces of the blade (6) of the rotary blade (7) and slidably contacted with the inner peripheral surface of the screen (3), and the rear portion of the concentrated sludge discharge zone (B). The apparatus for concentrating sludge and the like according to claim 1, wherein a cleaning pipe (14) is provided on the outer peripheral surface of the screen (3).