JP2010000473A - Screw press having flocculation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw press which is directly and continuously provided with a flocculation device to which a technology of a line mixer is applied. <P>SOLUTION: In the screw press, a line mixer 29 communicating with a filtration chamber 7 is continuously provided on the screw press 3 and brought into slidable contact with a screw shaft 6, an agitating vane 30 is disposed on the starting end wall portion of the line mixer 29, a sludge supply pipe 34 for raw liquid sludge and a chemical feed pipe 35 for a flocculant are connected to the vicinity of the agitating vane 30, and a plurality of baffle plates 36 etc. are fixed to the inner peripheral wall on the sludge outflow side. Combination of rapid agitation and the baffle plates in the small-diameter pipe eliminates uneven agitation to enable uniform floc formation. Dehydration carried out immediately after the floc formation eliminates destruction of flocs to increase drainability and improve dewaterability. The supply amount of the conditioned sludge can be increased at the same level as a screw press with a flocculating and mixing tank, which enables large-volume treatment by the scaling up of the screw press. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a screw press that adds a polymer to sludge generated from wastewater treatment facilities such as sewage, settlement drainage, human waste treatment, factory wastewater, etc., and in particular, installs a large coagulation and mixing tank in front of the screw press. Thus, a screw press in which a line mixer is directly connected to the screw press is provided.

Conventionally, screw presses for dewatering sewage sludge have to be dewatered after flocculation with a polymer, and as shown in Fig. 6, agglomerated sludge obtained by stirring and mixing sludge and aggregating agent in a coagulation mixing tank is supplied to the screw press. is doing. For example, Patent Document 1 discloses a screw press in which a mixing tank is installed and granulated flocs suitable for dehydration are supplied. In addition, the rotating shaft around which the screw blade is wound is arranged inside the horizontal cylindrical main body, the overflow wall is erected inside the main body, the sludge supply pipe side is the sludge adjustment chamber, For example, Patent Document 2 discloses a sludge treatment apparatus provided with a stirring blade on a rotating shaft.
Japanese Patent No. 3679369 (paragraph number 0013, FIG. 1) Japanese Patent Publication No. 06-15116 (Claim 1, FIG. 1)

  Conventional mixing tanks for agglomerating sewage sludge and the like with a polymer are relatively large, and a large agglomeration mixing tank is required on the stock solution supply port side of the screw press and a space for monitoring is required. As the dehydrator becomes larger, the agglomeration and mixing tank also becomes a large tank in order to maintain a predetermined residence time, and the peripheral speed of the stirrer is different between the central part and the peripheral part. In addition, the sludge treatment equipment provided with a sludge adjustment chamber inside the horizontal cylindrical body eliminates the need for a coagulation mixing tank installation space and a monitoring space. In the granulation, since the rotation speed of the stirring blade is slow, the generation state varies. When the conditioning chamber is installed in a screw press and is pressed and dehydrated, there is a possibility that the aggregated flocs may be missed from the screen.

  The present invention provides a screw press having an aggregating apparatus that is connected directly to a screw press by applying the technology of a line mixer and generates a good agglomerated floc.

  A screw press having a flocculation apparatus according to the present invention forms a filtration chamber with an outer cylinder screen and a screw shaft, supplies tempered sludge to the filtration chamber from a stock solution supply path installed in the screw shaft, and wraps around the screw shaft. In the screw press that removes the dehydrated cake from the discharge port, the line mixer that communicates with the filtration chamber is connected to the screw shaft and is in sliding contact with the screw shaft. A stirring blade is installed on the wall, and a sludge supply mud pipe and a flocculant chemical injection pipe are connected in the vicinity of the stirring blade. Since the agitation is performed in a small tube, there is no variation in the aggregated flocs, and a uniform floc can be formed. Immediately after the floc is formed, it is supplied to the screw press for dehydration, so that the floc is not broken and the drainage performance is improved and the dewaterability is improved.

  The line mixer that is connected to the screw press has multiple baffle plates fixed to the inner peripheral wall on the sludge outlet side, and the swirled mixed flow collides with the baffle plate to make it turbulent and promote flocking. At the same time, it is possible to supply the conditioned sludge that has been formed into an appropriate floc by the granulating action due to the reduction in speed and rectified into a linear flow into the filtration chamber. Moreover, the chemical injection pipe connected to the line mixer may be connected to a mud supply pipe, and is suitable for a screw press with a small installation space for auxiliary equipment.

  Another invention of the agglomeration device connected to the screw press is to remove the sludge pipe of the line mixer, expand the sludge inlet and configure the second line mixer, and connect the first line mixer to the sludge inlet Thus, two-stage aggregation is possible, and sludge that is difficult to aggregate in one stage can be applied. In addition, the agitation force is strengthened by two-stage aggregation, enabling large-capacity treatment, and the application target sludge can be expanded and the screw press can be enlarged.

  The configuration of the first line mixer consists of a stirring blade on the start wall and a plurality of baffle plates on the inner peripheral wall on the sludge outlet side, and a mud supply with a chemical injection pipe connected to the peripheral wall of the first line mixer. Two types of polymer flocculant, or separate flocculants such as inorganic flocculant and polymer flocculant, in the first line mixer and second line mixer. Can be used, and can be applied to the formation of uniform and strong flocs and to a higher range of sludge. Even if the supply amount of sludge of the screw press is increased, it can be applied to difficult-to-dehydrate sludge that requires no adjustment time and no flocs flocs variation. Moreover, the chemical injection pipe connected to the mud supply pipe of the first line mixer may be directly connected to the peripheral wall of the first line mixer.

  The present invention is configured as described above, and by connecting the line mixer to the inlet portion of the screw press, the axis of the screw shaft and the axis of the line mixer are made common, and the diameter of the aggregating apparatus is reduced. It is not necessary to install a large coagulation mixing tank on the stock solution supply side of the screw press, and the installation space for the coagulation device and the monitoring space are not required. If the second line mixer is connected to the line mixer, it can be applied to sludge that is difficult to agglomerate. Large capacity treatment of coagulated sludge is possible, and the size of the screw press can be increased.

  An embodiment of the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a longitudinal sectional view of a screw press having an aggregating device, and a screw press 3 supported on front and rear front frames 1 and 2 is as follows. An outer cylinder screen 4 having a screen stretched around its periphery and a screw shaft 6 around which screw blades 5 are wound are disposed. The screw shaft 6 is enlarged from the sludge supply side to the cake discharge side, and the filtration chamber 7 formed between the outer cylinder screen 4 and the screw shaft 6 has a volume as the condensed sludge is concentrated and dewatered. It has been reduced. An undiluted solution supply path 8 is provided in the screw shaft 6 so that conditioned sludge is supplied to the filtration chamber 7 from the supply hole 8a.

  In the embodiment of the present invention, the cylindrical outer cylinder screen 4 is divided into an outer cylinder screen 4a in the first half of the concentration zone A and an outer cylinder screen 4b in the second half of the filtration / dehydration zone B. An intermediate bearing 9 is interposed between the outer cylinder screen 4 a and the outer cylinder screen 4 b in the filtration / dehydration zone B, and the lower part of the outer cylinder screen 4 b in the filtration / dehydration zone B is supported by an outer cylinder support roller 10.

  FIG. 2 is an enlarged view of a main part on the stock solution supply side of the screw press, and a flange 11 connected to the supply side of the outer cylinder screen 4a of the concentration zone A is rotatably mounted on a rotary plate bearing 12 provided on the front frame 1. It is supported. A sprocket 13 is fitted on a flange 11 connected to the outer cylinder screen 4a, and is linked to a concentrating outer cylinder drive machine 14 mounted on the mount 1a of the front frame 1 and capable of rotating forward and backward. A bearing 15 fitted to the starting end wall portion of the screw shaft 6 is inserted through the flange 11 of the outer cylinder screen 4a.

  FIG. 3 is an enlarged view of the main part of the dewatering cake discharge side of the screw press, and a rotating plate bearing 17 in which a rotating plate 16 connected to the discharging side of the outer cylinder screen 4b in the filtration / dehydration zone B is disposed on the rear frame 2. A sprocket 18 fitted to the rotary plate 16 is linked to a dehydrator outer cylinder drive 19 mounted on the rear frame 2. The outer cylinder screen 4a in the concentration zone A and the outer cylinder screen 4b in the filtration / dehydration zone B can be rotated at a differential speed. A screw drive shaft 20 is connected to a rear end portion of the screw shaft 6 provided in the outer cylinder screen 4b, and the screw drive shaft 20 is supported by a bearing 21 provided on the frame 2a of the rear frame 2. A sprocket 22 is fitted on the screw drive shaft 20 and is linked to a screw drive machine (not shown). A back pressure adjusting presser 24 supported on a presser moving shaft 23 is disposed on the rear end side of the filtration chamber 7, and the presser 24 is connected to a moving cylinder 25 supported on the rear frame 2. The cake outlet 26 of the chamber 7 can be adjusted.

  The screw shaft 6 is rotated while the outer cylinder screen 4 a in the concentration zone A and the outer cylinder screen 4 b in the filtration / dehydration zone B are rotated at a different speed, and the conditioned sludge supplied to the filtration chamber 7 is supplied by the screw blade 5. The filtrate is transferred from the side toward the cake discharge side, and the filtrate is separated from the outer cylinder screens 4 a and 4 b and discharged to the filtrate trough 27 disposed below the filtration chamber 7. The tempered sludge becomes cake while being concentrated and dehydrated, and is discharged from the cake outlet 26 to the cake outlet 28 while receiving back pressure by the presser 24.

  FIG. 4 is an enlarged view of the aggregating apparatus connected to the screw press. A line mixer 29 supported on the front frame 1 is connected to the stock solution supply side of the screw press 3, and the line mixer 29 is connected to the screw shaft 6. The stock solution supply path 8 communicates with the filtration chamber 7. The bearing 15 of the screw shaft 6 is supported at the reduced rear end portion of the line mixer 29, and the rotating screw shaft 6 is slid on the line mixer 29. The axis of the screw shaft 6 and the axis of the line mixer 29 are common, and the diameter of the aggregating device is reduced. As shown in FIG. 4, a stirring blade 30 is disposed on the starting end wall portion of the line mixer 29, is pivotally supported by a bearing 31 provided on the end wall, and is supported on a pedestal 32 on the outer peripheral portion of the end wall. 33 is directly connected. A sludge supply pipe 34 for raw sludge and a chemical injection pipe 35 for a flocculant are connected to the peripheral wall of the line mixer 29, and the mud supply pipe 34 and the chemical injection pipe 35 are opened near the tip of the stirring blade 30. .

  The number of revolutions of the stirring blade 30 is appropriately changed depending on the concentration of the stock solution and the type of the flocculant, and is 200 to 600 rpm per minute. The stock solution and the flocculant are press-fitted in the vicinity of the tip of the stirring blade 30 and the stock solution and the flocculant Is rapidly stirred and mixed. A plurality of baffle plates 36 are radially attached to the inner peripheral wall of the line mixer 29 on the sludge outlet side. The rapidly swirling mixed swirling flow of the stock solution and the flocculant collides with the baffle plate 36 to be turbulent, and is supplied to the filtration chamber 7 from the stock solution supply path 8 of the rotating screw shaft 6 while promoting flocking. Since stirring is performed by a combination of the rapid stirring of the stirring blade 30 and the baffle plate in a pipe having a small diameter, there is no unevenness in stirring and variation in flocs, and uniform floc can be formed. Immediately after the formation of the floc, dewatering is performed, the floc is not destroyed, the water drainage is increased, and the dewaterability is improved. And it is not necessary to install a large flocculation mixing tank on the stock solution supply side of the screw press 3, and the installation space of the conventional flocculation apparatus and the monitoring space become unnecessary. It is possible to increase the supply amount of tempered sludge equivalent to a screw press provided with a coagulation mixing tank, and a large-capacity treatment can be performed by increasing the size of the screw press. Note that the plurality of baffle plates 36... Fixed to the inner peripheral wall of the line mixer 29 may be extended to the vicinity of the axial center of the line mixer 29, and the turbulence of the water flow can be promoted. Further, the chemical injection pipe 35 is not connected to the peripheral wall of the line mixer 29, but the chemical injection pipe 35 is connected to the mud supply pipe 34, and the mixed solution of the stock solution and the flocculant is supplied from the mud supply pipe 34 in the vicinity of the tip of the stirring blade 30. It may be press-fitted into.

  FIG. 5 shows another embodiment of the screw press having the aggregating device, in which the mud supply pipe 34 on the peripheral wall of the line mixer 29 provided with the stirring blades 30 and the baffle plates 36 shown in FIG. In the embodiment of the present invention, the second line mixer 37 having a structure in which the sludge inlet is expanded on the lower surface of the peripheral wall is configured, and the first line mixer 38 is connected to the sludge inlet 37a. The first line mixer 38 is provided with a stirring blade 39 on the start end wall portion, pivotally supported by a bearing 40 provided on the end wall, and directly connected to a stirring drive unit 42 supported on a base 41 on the outer peripheral portion of the end wall. is there. A plurality of baffle plates 43 are radially attached to the inner peripheral wall of the first line mixer 38 in the vicinity of the sludge inlet 37a of the second line mixer 37. A mud supply pipe 45 connected to a peripheral wall of the first line mixer 38 is connected to a flue agent pipe 44, and raw liquid sludge mixed with the flocculant is pressed into the vicinity of the tip of the stirring blade 39.

  The rotation speed of the stirring blade 39 of the first line mixer 38 shown in FIG. 5 is appropriately changed according to the concentration of the stock solution and the type of the flocculant, and is 200 to 600 rpm per minute, and is press-fitted into the first line mixer 38. The raw sludge mixed with the flocculant is rapidly stirred by the stirring blade 39 to cause the swirling flow to collide with the baffle plates 43... To promote turbulent flow and to form a flock while stirring the stirring blade of the second line mixer 37. Press fit near the tip of 30. Aggregated sludge during floc formation is rapidly agitated by the stirring blade 30 and divided, and the swirling flow of the agglomerated sludge that has been agitated and mixed is made to collide with the baffle plates 36. The tempered sludge in which the floc is formed is supplied to the filtration chamber 7 from the raw solution supply path 8 of the screw shaft 6. Although the rotation speed of the stirring blade 30 of the second line mixer 37 is also 200 to 600 rpm per minute, an appropriate floc can be formed by adjusting the speed according to the sludge flow rate and the coagulant used. The first line mixer 38 and the second line mixer 37 are connected to perform two-stage aggregation, and the aggregated floc can be subdivided to form a uniform strong floc. Even if the supply amount of sludge is increased, it can be applied to difficult-to-dehydrate sludge and the like that do not vary in flocs and require adjustment time. Large capacity treatment of the coagulated sludge becomes possible, and the size of the screw press 3 can be increased. In addition, two types of polymer flocculants, or separate flocculants such as inorganic flocculants and polymer flocculants, can be used for the first line mixer and the second line mixer. It is possible to form a uniform and strong floc, and it can be applied to a higher range of sludge. The plurality of baffle plates 43, 36,... Fixed to the inner peripheral walls of the first line mixer 38 and the second line mixer 37 may be extended to the vicinity of the shaft core, which promotes flocking. I can plan. Moreover, the chemical injection pipe 44 connected to the mud supply pipe 45 of the first line mixer 38 may be connected directly to the peripheral wall of the first line mixer 38.

  The screw press having the agglomeration apparatus of the present invention applies the technology of a line mixer and stirs and mixes in a small diameter tube by a combination of rapid stirring and a baffle plate. That is, a line mixer communicating with the filtration chamber is connected to the screw press and is slid on the screw shaft, and a stirring blade is disposed on the starting end wall portion of the line mixer, and a feed sludge supply pipe for raw sludge is provided in the vicinity of the stirring blade. And a flocculant chemical injection pipe are connected, and multiple baffle plates are fixed to the inner peripheral wall on the sludge outlet side. Since the agitation is performed, there is no variation in the aggregated floc, and a uniform floc can be formed. Immediately after the formation of the floc, dewatering is performed, the floc is not destroyed, the water drainage is increased, and the dewaterability is improved. It is possible to increase the supply amount of tempered sludge equivalent to that of a screw press provided with a coagulation mixing tank, and it can be applied to difficult-to-dehydrate sludge that requires adjustment time, and a large-capacity treatment can be performed by increasing the size of the screw press. It becomes an optimal screw press that adds a polymer to the sludge generated from wastewater treatment facilities such as sewage, settlement drainage, human waste treatment, and factory wastewater, and presses and dehydrates.

It is a longitudinal cross-sectional view of the screw press which has the aggregation apparatus which concerns on this invention. Similarly, it is a principal part enlarged view of the stock solution supply side of a screw press. Similarly, it is a principal part enlarged view of the dewatering cake discharge | emission side of a screw press. Similarly, it is an enlarged view of the aggregating apparatus connected to the stock solution supply side of the screw press. Similarly, it is the longitudinal cross-sectional view of the other Example of the screw press which has an aggregating apparatus. It is a conceptual diagram of the screw press using the conventional type coagulation mixing tank.

Explanation of symbols

3 Screw press 4 Outer cylinder screen 5 Screw blade 6 Screw shaft 7 Filtration chamber 8 Stock solution supply path 26 Discharge port 29 Line mixer 30, 39 Stirring blade 34, 45 Mud supply pipe 35, 44 Drug injection pipe 36, 43 Baffle plate 37 First Two-line mixer 37a Sludge inlet 38 First line mixer

Claims (6)

A filtration chamber (7) is formed by the outer cylinder screen (4) and the screw shaft (6), and conditioned sludge is supplied to the filtration chamber (7) from the raw solution supply path (8) inscribed in the screw shaft (6). A line communicating with the filtration chamber (7) in a screw press that concentrates and dehydrates while transferring conditioned sludge with a screw blade (5) wound around the screw shaft (6) and takes out the dehydrated cake from the discharge port (26). The mixer (29) is continuously connected to the screw shaft (6) and brought into sliding contact, and the stirring blade (30) is disposed on the starting end wall portion of the line mixer (29), and the raw sludge is disposed near the stirring blade (30). A screw press having a flocculation apparatus, wherein a mud supply pipe (34) and a chemical injection pipe (35) for a flocculant are connected. The screw press having the aggregating apparatus according to claim 1, wherein a plurality of baffle plates (36) are fixed to an inner peripheral wall of the line mixer (29) on the sludge outlet side. The screw press having the aggregating apparatus according to claim 1 or 2, wherein a chemical injection pipe (35) connected to the line mixer (29) is connected to a mud supply pipe (34). The mud pipe (34) of the line mixer (29) is removed, the sludge inlet (37a) is expanded to form a second line mixer (37), and the first line mixer is connected to the sludge inlet (37a). The screw press having an aggregating apparatus according to claim 1 or 2, wherein (38) is connected. A stirring blade (39) is disposed on the starting end wall of the first line mixer (38), and a plurality of baffle plates (43...) Are disposed on the inner peripheral wall on the sludge outlet side. The screw press having the agglomeration device according to claim 4, wherein a mud supply pipe (45) having a chemical injection pipe (44) connected thereto is connected to a peripheral wall of the above. The screw press having an agglomeration device according to claim 5, wherein a chemical injection pipe (44) connected to the mud supply pipe (45) is connected to a peripheral wall of the first line mixer (38).