JP2007054684A - Sludge-flocculating device and sludge treatment apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the efficiency of solid-liquid separation in a sludge-flocculating device for flocculating sludge fed to a solid-liquid separator by separating water from the sludge before being fed to the solid-liquid separator to increase the solid concentration of the sludge, and feeding the sludge whose concentration has been increased to the solid-liquid separator. <P>SOLUTION: The sludge-flocculating device comprises a mixing tank 3 into which sludge and a coagulant are fed, a cylindrical body 17 disposed in the mixing tank, a screw 21 disposed in the cylindrical body, an agitation vane 10 for agitating the sludge and coagulant fed into the mixing tank 3, and a common motor 9 for rotating and driving the agitation vane 10 and screw 21. The cylindrical body 17 has a plurality of fixed rings 28 arranged at intervals between them, and movable rings 29 each disposed between the adjacent fixed rings 28, and the internal diameter of the movable ring 29 is set to be smaller than the external diameter of the screw 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sludge flocking device that flocates sludge treated by a solid-liquid separation device prior to the treatment, and a sludge treatment device having the flocking device and the solid-liquid separation device.

  2. Description of the Related Art Conventionally, a sludge treatment apparatus that solid-liquid separates sludge that has been flocked by a sludge flocking apparatus using a solid-liquid separator (see, for example, Patent Documents 1 to 4). When treating sludge with such a sludge treatment device, if the solid content concentration (floating matter concentration) of the sludge sent to the solid-liquid separation device is low, the amount of solid content that can be separated from the sludge decreases, and the sludge is efficiently solidified. Liquid separation is not possible. In the sludge flocking device, if a part of liquid is separated from the sludge, the solid content concentration of the sludge can be increased, and the sludge having the increased concentration can be sent to the solid-liquid separation device. Although the solid content can be separated, conventionally, such a sludge flocking apparatus has not existed.

JP-A-5-228695 JP 2004-357615 A JP 2001-198599 A Japanese Patent Laid-Open No. 9-220596

  The present invention has been made on the basis of the above-described novel recognition, and its object is to make a sludge floc capable of separating a part of liquid from sludge before being processed by a solid-liquid separator. It is providing the sludge processing apparatus which has an apparatus, the sludge flocification apparatus, and a solid-liquid separator.

  In order to achieve the above object, the present invention provides a mixing tank into which sludge and a flocculant are fed, a cylindrical body disposed in the mixing tank, a screw disposed in the cylindrical body, and an outside of the cylindrical body. And a stirring means for stirring the sludge and the flocculant fed into the mixing tank, and a common drive device for rotationally driving the stirring means and the screw. It has a plurality of fixed rings arranged at intervals and a movable ring arranged between adjacent fixed rings, and the inner diameter of the movable ring is set smaller than the outer diameter of the screw. The characteristic sludge flocification apparatus is proposed (Claim 1).

  Similarly, in order to achieve the above object, the present invention comprises the sludge flocification device according to claim 1 and a solid-liquid separation device for solid-liquid separation of the sludge flocked by the sludge flocking device, The present invention proposes a sludge treatment apparatus configured to discharge the filtrate that has flowed into the cylindrical body of the sludge flocking apparatus to a place other than the solid-liquid separator (claim 2).

  According to the present invention, even when the solid content concentration of the sludge to be treated is low, the sludge flocking device can separate the liquid content from the sludge and increase the solid content concentration of the sludge sent to the solid-liquid separation device. Therefore, sludge can be efficiently solid-liquid separated by the solid-liquid separator.

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

  FIG. 1 is a partial cross-sectional view showing the entire sludge treatment apparatus. The sludge treatment apparatus shown here has a sludge flocking apparatus 1 and a solid-liquid separation apparatus 2 for solid-liquid separating the sludge flocked by the sludge flocking apparatus 1.

  The sludge flocking apparatus 1 has a mixing tank 3 as shown in FIG. 2, and a sludge inlet 5 through which sludge before flocking flows into the mixing tank 3 is formed on the side wall 4 of the mixing tank 3. Has been. A flocculant injection port 7 into which the flocculant flows is formed in the bottom wall 6 of the mixing tank 3, and a motor 9 with a speed reducer is fixedly supported on the upper wall 8 of the mixing tank 3. Furthermore, a stirring blade 10 that is rotationally driven by a motor 9 is disposed in the mixing tank 3.

  Examples of sludge that can be solid-liquid separated by the sludge treatment apparatus shown in FIG. 1 and FIG. 2 include wastewater discharged from sewage treatment products, pig farms, food processing wastewater, waste milk, and waste tofu with added water. Organic sludge, and inorganic sludge such as cutting oil containing cutting waste, plating waste oil, ink waste liquid, pigment waste liquid, and paint waste liquid, and the like. Here, sludge containing a large amount of moisture is treated. Such sludge is treated with water in a water treatment system, if necessary, and then stored in a sludge tank (not shown). Here, a coagulation accelerator made of, for example, ferric sulfate is added to the sludge. . Next, the sludge is weighed by a metering device (not shown), and an amount of sludge that matches the processing capacity of the solid-liquid separator 2 is fed into the mixing tank 3 from the sludge inlet 5 as indicated by an arrow A. As this metering device, for example, a metering tank or a metering pump described in Patent Document 2 or 3 described above can be used. The moisture content of the sludge sent to the mixing tank 3 is, for example, about 99% by weight.

  On the other hand, as shown by an arrow B from the flocculant inlet 7, a flocculant made of, for example, a polymer flocculant is fed into the mixing tank 3. The sludge and the flocculant thus fed into the mixing tank 3 are mixed and stirred by the stirring blade 10 that is rotationally driven by the motor 9, whereby the sludge is flocked. In FIG. 2, the code | symbol S is attached | subjected with respect to this sludge. Thus, the stirring blade 10 serves to stir the sludge and the flocculant fed into the mixing tank 3 and constitutes an example of a stirring means.

  The sludge flocked as described above flows out from the sludge outlet 11 formed on the side wall 4 of the mixing tank 3 and is transferred to the solid-liquid separation device 2 shown in FIG. Solid-liquid separation. Since the specific configuration and action for solid-liquid separation of sludge are conventionally known, the description thereof is omitted here.

  The water separated from the sludge, that is, the filtrate, is received by the receiving member 13 as shown by an arrow C in FIG. 1 and then flows down in the discharge pipe 14. Since this filtrate still contains some solid content, it is treated again with other sludge and then sent again to the sludge flocking device 1 for flocking. Dehydration is performed by the solid-liquid separator 2. The filtrate flowing down in the discharge pipe 14 can be discharged directly into a river or the like and discarded.

  On the other hand, the sludge from which moisture has been separated and the water content has decreased is discharged from the solid-liquid separator 2 as indicated by an arrow D. The water content of the sludge after the dehydration treatment is, for example, about 80 to 85% by weight. In FIG. 1, illustration of the filtrate separated by the solid-liquid separator 2 and the sludge having a reduced water content is omitted.

  As the solid-liquid separation device 2, an appropriate device known per se, for example, the solid-liquid separation device described in Patent Document 1 or 2 described above can be widely used.

  As described above, the sludge flocking apparatus 1 of the present example includes the mixing tank 3 into which the sludge and the flocculant are fed, and the stirring means for stirring the sludge and the flocculant fed into the mixing tank 3. . If the solid content concentration of the sludge sent from the sludge flocking device to the solid-liquid separation device is low, the solid content cannot be efficiently separated from the sludge in the solid-liquid separation device.

  Therefore, the sludge flocking apparatus 1 of this example removes a part of the water from the sludge sent here to increase the solid content concentration of the sludge, and the sludge having the increased concentration is separated into the solid-liquid separator 2. It is configured to send in. Hereinafter, a specific configuration example regarding this will be described.

  As shown in FIG. 2, a cylindrical body 17 located between the upper plate 15 and the lower plate 16 is disposed in the mixing tank 3 of the sludge flocking device 1. The cylindrical body 17 includes a plurality of fixed rings 28 that are spaced apart from each other in the axial direction by small ring-shaped spacers 38, and a movable ring 29 that is disposed between the fixed rings 28 that are adjacent in the axial direction. It is constituted by.

  The plurality of fixed rings 28 and the plurality of movable rings 29 are arranged in the vertical direction. FIG. 3 is a perspective view showing the appearance of one fixed ring 28, one movable ring 29, and spacer 38. As shown in FIGS. 2, 4, and 5, the plurality of fixing rings 28 are arranged concentrically, and spacers 38 are respectively arranged between the fixing rings 28 adjacent in the axial direction.

  In the illustrated sludge flocking device 1, as shown in FIGS. 3 to 5, each fixing ring 28 is formed with four mounting holes 32 arranged at intervals in the circumferential direction, and a plurality of mounting holes 32 are formed. Each mounting hole 32 formed in the fixing ring 28 is located concentrically. A stay bolt 34, which is an example of a connecting member, passes through each mounting hole 32 formed in each fixing ring 28 and the center hole of the spacer 38 disposed between the fixing rings 28 adjacent in the axial direction. Each of the stay bolts 34 extends through the upper plate 15 and the lower plate 16 as shown in FIG. 2, and nuts 18 and 19 are screwed into male screws formed at respective longitudinal ends of the stay bolts 34. The cylindrical body 17, the upper plate 15, and the lower plate 16 are integrated. It is also possible to assemble the fixing rings 28 spaced apart from each other by spacers so as to be slightly movable. In FIG. 2, illustration of some of the stay bolts and spacers is omitted for easy understanding of the drawing.

  As shown in FIG. 5, the thickness T of each movable ring 29 arranged between each fixed ring 28 is set smaller than the gap width G between the fixed rings, and the end face of each fixed ring 28 A minute gap g of about 0.1 to 2 mm, for example, is formed between the end faces of the movable ring 29 facing the surface. As will be described later, the gap g allows moisture separated from the sludge in the mixing tank 3, that is, the filtrate to pass therethrough. The thickness T of the movable ring 29 is set to about 1.0 mm to 2 mm, for example, and the gap width G is set to about 2 mm to 3 mm, for example. The thickness t of the fixing ring 28 is set to about 1.5 mm to 3 mm, for example.

On the other hand, the outer diameter D ₁ of each movable ring 29 is smaller than the diameter D _{2 of the} circle CC (FIG. 3) formed by the inner surfaces of the four spacers 38 positioned around the movable ring 29, and each of the fixed rings 28. It is set larger than the inner diameter D _3. With this configuration, each movable ring 29 is movable in the radial direction without detaching from between each fixed ring 28. Thus, a plurality of stay bolts 34 are provided so that the movable ring 29 located inside the spacer 38 fitted to each stay bolt 34 does not fall out between the fixed rings 28, and preferably three or more. Stay bolts are provided. In the sludge floc apparatus of this example, four stay bolts 34 are used, and as can be seen from FIG. 4, these stay bolts 34 are arranged at equal intervals in the circumferential direction of the fixing ring 28. As described above, the plurality of connecting members are arranged so as to prevent the movable ring 29 from being separated from between the adjacent fixed rings 28.

  The lower plate 16 shown in FIG. 2 is detachably fixed to the upper end portion of the pipe 20 with bolts and nuts. The lower end portion of the pipe 20 is connected to the bottom wall 6 of the mixing tank 3 along with the drainage pipe 22. It is detachably fixed by a nut. The pipe 20 and the drainage pipe 22 communicate with each other through a hole 23 formed in the bottom wall 6, and the pipe 20 communicates with the inside of the cylindrical body 17 through an opening 24 formed in the lower plate 16. Yes. As shown in FIG. 1, the drain pipe 22 is connected to the above-described drain pipe 14, and an open / close valve 31 is interposed in the drain pipe 22.

  Further, a screw 21 extending substantially in the vertical direction is disposed inside the plurality of fixed rings 28 and the movable ring 29. The screw 21 has a shaft portion 41 and a spiral blade portion 42 integral therewith. ing. As shown in FIG. 2, the shaft portion 41 of the screw 21 extends through the hole 25 formed in the upper plate 15 and the opening 24 formed in the lower plate 16, and the upper end of the shaft portion 41 is a motor. 9 is detachably fixedly connected to an output shaft (not shown). The hole 25 formed in the upper plate 15 has a diameter slightly larger than the diameter of the shaft portion 41 of the screw 21 fitted therein, but the opening 24 formed in the lower plate 16 passes therethrough. It has a diameter much larger than the diameter of the extending screw 21.

  As shown in FIGS. 2 and 6, the base end portions of four stays 26 extending toward the center of the pipe 20 are fixed to the inner wall surface of the pipe 20. The bearing housing 27 is fixed, the bearing 30 is fitted into the bearing housing 27, and the lower end portion of the shaft portion 41 of the screw 21 is rotatably held by the bearing housing 27 via the bearing 30. Yes.

  Moreover, the upper end part of the above-mentioned stirring blade 10 is detachably fixed to the shaft part 41 of the screw 21. The stirring blade 10 is located outside the cylindrical body 17.

  As described above, the sludge and the flocculant are fed into the mixing tank 3, and at this time, the screw 21 is driven to rotate by the motor 9, whereby the stirring blade 10 is also rotated, and the sludge and the flocculant are stirred by the rotation, Sludge is flocked. A cylindrical body 17 is disposed in the mixing tank 3, and the minute gap g shown in FIG. 5 is formed between the fixed ring 28 and the movable ring 29 of the cylindrical body 17. The moisture of the sludge that is flocked in 3 flows into the cylindrical body 17 through the minute gap g. The gap g is set to a size that prevents the floc from passing therethrough.

  As described above, the water that has flowed into the cylindrical body 17 through the gap g between the fixed ring 28 and the movable ring 29, that is, the filtrate, passes through the opening 24 formed in the lower plate 16 and enters the tube 20. 2 and further passes through a hole 23 formed in the bottom wall 6 of the mixing tank 3 as shown by an arrow E in FIG. 2, passes through the drainage pipe 22, and flows into the discharge pipe 14 shown in FIG. To do. In this way, the filtrate that has flowed into the cylindrical body 17 through the gap g is treated with water again together with the filtrate discharged from the solid-liquid separator 2, and then sent again to the sludge flocking device 1 for flocs. Or released into rivers. Thus, the filtrate that has flowed into the cylindrical body 17 through the gap g between the fixed ring 28 and the movable ring 29 of the cylindrical body 17 of the sludge flocking apparatus 1 directly enters the solid-liquid separator 2. It is not sent and discharged to a place other than the solid-liquid separator 2. In FIG. 1, FIG. 2, FIG. 5 and FIG. 6, illustration of the filtrate flowing into the cylindrical body 17 is omitted.

  If the on-off valve 31 is closed, the filtrate flowing into the cylindrical body 17 does not flow into the discharge pipe 14, and the sludge flocking device 1 can function in the same manner as a conventional flocking device.

  As described above, the sludge flocking device 1 of the present example includes the cylindrical body 17 disposed in the mixing tank 3, and the cylindrical bodies 17 are arranged with a plurality of fixing rings spaced from each other. 28 and a movable ring 29 disposed between the adjacent fixed rings 28, and a stirring means for stirring the sludge and flocculant fed into the mixing tank 3 is disposed outside the cylindrical body. Moisture is separated from the sludge sent to the tank 3, the solid content concentration of the sludge is increased, and the sludge having the increased concentration can be sent to the solid-liquid separator 2. As a result, the solid-liquid separation device 2 can perform solid-liquid separation efficiently.

  By the way, if the solid body of sludge is clogged in the gap g of the cylindrical body 17, the water | moisture content in sludge cannot be efficiently flowed into the inside of the cylindrical body 17. FIG. Therefore, the sludge flocking apparatus 1 of the present example is provided with the above-described screw 21 disposed in the cylindrical body 17 and employs the following configuration.

As shown in FIG. 5, the outer diameter D ₄ of the screw 21 is set to be slightly smaller than the inner diameter D ₃ of the fixed ring 28 so that its rotation is not hindered. It is set larger than D _5. The inner diameter D ₅ of the movable ring 29 is set smaller than the outer diameter D _{4 of the} screw 21. For this reason, when the screw 21 is rotationally driven by the motor 9 as described above, the rotation of the screw 21 causes each movable ring 29 to be pushed and moved by receiving external force from the screw 21, and positively against the fixed ring 28. Relative movement. In this way, the solid matter that has entered the gap g can be positively discharged without providing a dedicated driving means for driving the movable ring 29, and the gap g is automatically cleaned. Can be prevented.

  In addition, since the motor 9 rotationally drives both the stirring blade 10 and the screw 21, it is possible to effectively suppress the cost increase of the sludge flocking device 1. The motor 9 constitutes an example of a driving device that rotationally drives the stirring blade 10 and the screw 21. The sludge flocking device is provided with a common drive device that rotationally drives the stirring means and the screw.

  In the specific example described above, a small ring-shaped member that is a member different from the fixing ring 28 is used as the spacer 38, but the spacer can also be formed integrally with the fixing ring. For example, the spacer 38 may be formed integrally with one of the two fixing rings adjacent to the spacer 38, and the fixing ring 28 and the spacer 38 may be configured as one component. More specifically, when both the fixing ring 28 and the spacer 38 are made of metal, they can be integrated by welding or can be integrally formed by casting. Alternatively, the integrated fixing ring 28 and spacer 38 can be manufactured by cutting the material. Further, when both the fixing ring 28 and the spacer 38 are made of resin, they can be manufactured as an integral molded product by a molding die.

  In each of the specific examples described above, one movable ring 29 is disposed between the fixed rings 28 adjacent in the axial direction, but a plurality of movable rings 29 are provided between the fixed rings 28 adjacent in the axial direction. Of course, it may be arranged. At least one movable ring is disposed between adjacent fixed rings. Similarly, the screw 21 of the illustrated solid-liquid separator has one blade portion 42 extending in a spiral shape, but it is natural that a screw having a plurality of blade portions extending in a spiral shape may be used. is there. The screw has at least one blade.

  Furthermore, the fixed ring 28, the movable ring 29, and the screw 21 can be made of metal such as stainless steel. However, if at least a part of these is made of resin, the cost can be reduced and each of the components can be reduced. The weight of the element can be reduced.

  Moreover, each structure demonstrated above divides the mixing tank of a sludge flocking device into the 1st stirring chamber and the 2nd stirring chamber, as disclosed by Unexamined-Japanese-Patent No. 9-220596. By feeding sludge and agglomeration promoter into one stirring chamber and stirring them, and then feeding the sludge into the second stirring chamber and supplying the flocculant to the second stirring chamber and stirring them Also, the present invention can be applied to a sludge flocking device that flocates sludge. In the case of such a sludge flocking device, a cylindrical body is provided in the second stirring chamber, a screw is provided in the cylindrical body, and the filtrate flowing into the cylindrical body is removed in the same manner as described above. What is necessary is just to discharge to places other than a solid-liquid separator.

It is a fragmentary sectional view which shows an example of a sludge processing apparatus. It is an expanded sectional view of a sludge floc apparatus. It is a perspective view which shows one fixed ring, one movable ring, and a spacer. It is a disassembled perspective view of a cylindrical body and a screw. It is a longitudinal cross-sectional view of a cylindrical body. FIG. 6 is an enlarged sectional view taken along line VI-VI in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sludge flocking device 2 Solid-liquid separator 3 Mixing tank 17 Cylindrical body 21 Screw 28 Fixed ring 29 Movable ring g Gap D ₄ Outer diameter D ₅ Inner diameter

Claims (2)

A mixing tank into which sludge and a flocculant are fed, a cylindrical body arranged in the mixing tank, a screw arranged in the cylindrical body, and arranged outside the cylindrical body and fed into the mixing tank A plurality of fixed rings, each of which has a stirring means for stirring the sludge and the flocculant, and a common driving device for rotationally driving the stirring means and the screw. And a movable ring disposed between adjacent fixed rings, wherein the inner diameter of the movable ring is set smaller than the outer diameter of the screw. The sludge flocking device according to claim 1 and a solid-liquid separation device for solid-liquid separation of sludge flocked by the sludge flocking device, and the filtrate flowing into the cylindrical body of the sludge flocking device The sludge treatment apparatus is configured to discharge the gas to a place other than the solid-liquid separator.

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