JP6708975B2 - Clogging prevention device for screw press - Google Patents

Description

The present invention, while dehydrating sludge in a cylindrical outer cylinder screen, in a screw press that conveys the dehydrated cake with the screw blades of the screw shaft inserted in the outer cylinder screen, in order to prevent clogging of the outer cylinder screen The present invention relates to a device for preventing clogging of a screw press fixed to a screw blade.

Conventionally, non-compressible sludge generated from sewage treatment plants, etc. and non-compressible sludge generated from water purification plants perform flocculation of suspended solids by adding a flocculant to perform solid-liquid separation, and dehydration cake We are trying to reduce the water content. Such sludge apparatus for concentrating and dehydrating a screw press for performing solid-liquid separation of sludge want such to rotate the screw shaft that is provided inside the outer cylinder screen are known.

Then, in order to prevent the cake from being attached to and clogging the inner surface of the outer cylinder screen of the screw press, a technique of providing a series of strip-shaped scrapers on the outer peripheral portion of the spiral screw blade is well known. .

Patent Document 1 describes a scraper provided on a screw blade, in which a mounting portion of the scraper is configured by an inclined surface to enable movement of the scraper in an outer peripheral direction according to a tightening condition of a mounting bolt. ing.

Further, Patent Document 2 describes a technique in which a flow path is formed inside a scraper made of an elastic body and the flow path is expanded and contracted toward the inner wall of the outer cylinder screen by the pressure of the fluid injected into the flow path.

Japanese Patent No. 3858701 JP 2001-321990 A

The conventional flexible scraper elastically presses against the inner surface of the outer cylinder screen to eliminate the clogging of the screen. However, just by pressing the scraper like the scraper of the cited document 1, When the scraper sliding contact part is worn out and cannot be slidably contacting the outer cylinder screen, the scraper needs to be replaced, which requires time and labor.

In the cited document 1, the scraper can be moved in the outer peripheral direction according to the wear of the scraper, but since it has a structure in which it can be moved by tightening the mounting bolt, the scraper can be moved outside when adjusting the scraper. Need to remove the tube screen. In many cases, the dehydration section is covered with a cover or the like as a measure against odors, and much time and labor are required for disassembling and assembling for adjusting the scraper as in the conventional technique.

Patent Document 2 is configured to expand and contract by the pressure supplied to the flow path inside the scraper, but it is unclear what means is used to supply the pressure to the flow path inside the scraper. When the pressure cannot be supplied from the outside, the outer cylinder screen needs to be removed as in the prior art, so disassembling and assembling requires a lot of time and labor. Further, it is difficult to form a groove on the outer peripheral end of the spiral screw blade, and it is not realistic to fit a scraper into the groove.

The present invention provides a clogging prevention device for a screw press, which allows a scraper provided on a screw blade to be moved in the outer peripheral direction without disassembling the screw press.

INDUSTRIAL APPLICABILITY The present invention forms a filtration chamber by rotatably installing a screw shaft wound with screw blades inside an outer cylinder screen and conveys sludge supplied from one end side of the filtration chamber to the other end while dehydrating the sludge. In a device for preventing clogging of a screw press that discharges the dehydrated cake, a tubular adjusting device attached to the outer peripheral part of the screw blade and capable of expanding and contracting according to the internal pressure, and an outer cylinder screen according to the expansion and contraction of the adjusting device. The scraper that can move in any direction, the holding plate that holds the scraper so that it can move in the direction of the outer cylinder screen, the rotary swivel joint at the end of the screw shaft, and the screw shaft that is inserted into the rotary swivel joint. And a pressure supply pipe having the other end connected to the adjusting tool, and the scraper provided on the screw blade can be moved in the outer peripheral direction without disassembling the screw press.

The screw blades are divided into each zone according to the internal pressure of the filtration chamber, the adjustment tools are arranged independently in each division, and the pressure supply pipes are connected to each adjustment tool. Individually adjustable, only scrapers in worn zones can be moved.

An adjusting tool attached to the outer peripheral edge of the screw blade and a scraper adjacent to the outer cylinder screen side of the adjusting tool are provided.Pressing plates are arranged on the front and rear surfaces of the screw blade. There are few members that project to the front and back of the sludge, so the sludge transfer resistance does not increase

Equipped with an adjuster attached to the outer circumference of either the front or rear surface of the screw blade, and a scraper adjacent to the outer cylinder screen side of the adjuster, and press it outside the surface on which the adjuster and scraper are arranged. The configuration in which the plate is arranged and the adjusting tool and the scraper are sandwiched between the screw blade and the pressing plate is effective when the thickness of the screw blade is small and the screw blade and the scraper cannot be arranged at the outer peripheral end of the screw blade.

The clogging prevention device of the screw press in the present invention can move the scraper in the outer peripheral direction without disassembling the screw press. Further, if the adjusters that allow the scrapers to move are independently connected to the zones of the filtration chamber having different pressing forces, only the scrapers in the worn zones can be individually adjusted. Regardless of the operating time of the screw press, the scraper is always in sliding contact with the outer cylinder screen, so the dehydrated cake does not flow backwards in the filtration chamber and the screen is not clogged, so the dehydration performance of the screw press is stable. Can be converted.

It is a partial longitudinal side view of the screw press which concerns on this invention. Similarly, it is an enlarged view of a screw blade outer peripheral portion. It is an enlarged view of the screw blade outer peripheral part of other Example 1 which concerns on this invention. Similarly, it is an enlarged view of the screw blade outer peripheral part of other Example 2. FIG. It is a principal part longitudinal cross-sectional side view of the screw blade|wing which concerns on this invention. Similarly, it is a vertical cross-sectional plan view of a main part of a screw blade. It is a principal part longitudinal cross-sectional side view of the screw blade of other Example 3 which concerns on this invention. It is a connection diagram of a pressure supply pipe according to the present invention.

FIG. 1 is a partially longitudinal side view of a screw press according to the present invention.
The screw press 1 is supported between the front and rear frames 2 and 3, and has a screw shaft 6 in which a screw blade 5 is wound around an outer cylinder screen 4 having a filtration surface on the peripheral portion. The diameter of the screw shaft 6 disposed inside the outer cylinder screen 4 increases in a taper shape from the starting end side toward the terminal end side, and the outer cylinder screen 4 and the screw shaft 6 are relatively spaced from each other in the extending direction. I am trying to reduce it.

A supply path 7 is provided on the starting end side of the screw shaft 6, and sludge in the stock solution tank 8 is press-fitted into the supply path 7 by a press-fitting pump 9. The press-fit sludge is pressed into the starting end of the supply port 7a Kararo over the chamber 10 of the supply path 7 provided on the screw shaft 6, from the outer cylinder subscription over down 4 while conveying a screw vane 5 wound around the screw shaft 6 The filtrate is separated and the cake is taken out from the discharge port 11 at the rear end. The solid matter that has been solid-liquid separated forms a cake layer on the inner surface of the outer cylinder screen 4.

A screw drive shaft 12 is connected to the rear end of the screw shaft 6, and a drive sprocket 13 is fitted on the screw drive shaft 12. The sprocket 13 is driven by a screw driving machine (not shown) to rotate the screw shaft 6.

A series of scrapers 14 are arranged on the screw blade 5 wound around the screw shaft 6 from the beginning to the end of the screw blade 6 at the outer peripheral tip of the screw blade 5. A rotary swivel joint 15 is provided on the terminal side of the screw shaft 6, and the pressure fluid from the pressure supply device 16 is supplied to the scraper 14 via a pressure supply pipe 17 inserted in the screw shaft 6 . The pressure supply pipe 17 has one end connected to the rotary swivel joint 15 and the other end connected to the adjusting tool 18. The inner ring of the rotary swivel joint 15, the pressure supply pipe 17, and the screw shaft 6 rotate.

It is needless to say that the specific configuration of each part of the screw press 1 is not limited to the description of the embodiment, and can be changed as appropriate within the range in which the function and effect of the present invention are exhibited.

FIG. 2 is an enlarged view of the outer peripheral portion of the screw blade according to the present invention.
A scraper 14 is provided on the outer peripheral portion of the screw blade 5, and the end of the scraper 14 is elastically brought into sliding contact with the inner surface of the outer cylinder screen 4. With the rotation of the screw shaft 6, the scraper 14 mounted on the screw blade 5 elastically slidably contacts the inner surface of the outer cylinder screen 4, and the cake that accumulates on the inner surface of the screen and blocks the pores is peeled and conveyed. Efficient filtration dehydration can be performed.

In this embodiment, the scraper 14 is arranged adjacent to the outer cylinder screen 4 side of the adjusting tool 18 attached to the outer peripheral end of the screw blade 5, and is clamped by the holding plates 19, 19. The inner surface of the holding plate 19 has a shape corresponding to the outer surface of the scraper 14, a predetermined clearance is provided between the holding plate 19 and the scraper 14, and the scraper 14 is vertically movable.
The holding plate 19 is arranged on the front and rear surfaces of the screw blade 5, and is fixed by a bolt 20 and a nut 21. The bolt 20 penetrates the screw blade 5 and the front and rear holding plates 19, 19.

Since the scraper 14 is elastically slidably in contact with the inner surface of the outer cylinder screen 4, a member formed of rubber, resin, or the like having lower wear resistance than the outer cylinder screen 4 can be used. A large contact surface is not required for the outer cylinder screen 4, but it is necessary to move vertically according to the expansion and contraction of the adjusting tool 18 and to prevent tilting in the front-rear direction, so the contact surface with the adjusting tool 18 is large. It is desirable that the clearance between the holding plates 19 to be clamped is as small as possible.

In this embodiment, the scrapers 14 are formed in multiple stages so that the width thereof becomes narrower toward the outer cylinder screen 4, and the side faces of the respective widths are supported by the holding plate 19 formed in the same shape. In particular, if the clearance close to the outer cylinder screen 4 is made small, when the scraper 14 scrapes off the sludge accumulated on the outer cylinder screen 4, the sludge accumulates between the scraper 14 and the holding plate 19. Can be prevented.

FIG. 3 is an enlarged view of a screw blade outer peripheral portion of another embodiment 1 according to the present invention.
The scraper 14 has a shape in which the width thereof is gradually reduced toward the tip, and the pressing plates 19 and 19 support the front and rear surfaces of the scraper 14. Since the contact surface to the outer cylinder screen 4 is made small, the resistance at the time of sliding contact is small, and the tilting in the front-rear direction can be prevented by sufficiently securing the contact surface of the front and rear surfaces of the scraper 14 with the holding plate 19. By adjusting the width of the scraper 14 on the adjusting tool 18 side to the adjusting tool 18, the accuracy of movement of the scraper 14 with respect to the expansion and contraction of the adjusting tool 18 is increased. The scraper 14 and the pressing plate 19 are simple in shape and easy to manufacture.

FIG. 4 is an enlarged view of a screw blade outer peripheral portion of another embodiment 2 according to the present invention.
A pressing plate 19 is provided on one of the front and rear surfaces of the screw blade 5 along the outer peripheral portion of the screw blade 5, and an adjusting tool 18 is provided between the pressing plate 19 and the screw blade 5 and an outer cylinder screen 4 of the adjusting tool 18. The scraper 14 is adjacent to the side, and the vicinity of the end of the scraper 14 is projected to be in sliding contact with the outer cylinder screen 4. By arranging the pressing plate 19 outside the surface where the adjusting tool 18 and the scraper 14 are arranged and supporting the front and rear surfaces of the scraper 14 by sandwiching them with the screw blades 5 and the pressing plate 19, it is possible to prevent tilting in the front-back direction. .. This is an effective configuration when the thickness of the screw blade 5 is small and cannot be arranged at the outer peripheral end of the screw blade 5.

In the present embodiment, the adjusting tool 18 and the scraper 14 are adjacent to each other so as to be in direct contact with each other. However, if the scraper 14 can move in the direction of the outer cylinder screen 4 according to the expansion and contraction of the adjusting tool 18, For example, the configuration is not limited, such as interposing another member between both members.

5 and 6 are a vertical sectional side view and a vertical sectional plan view of a main part of a screw blade according to the present invention.
The adjusting tool 18 is a tubular member, and a pressure fluid is supplied to the inside. The material used is an elastic body such as deformable rubber, which can expand and contract according to the internal pressure. Since the scraper 14 is moved in the direction of the outer cylinder screen 4 when the adjusting tool 18 is expanded or contracted, both side surfaces of the adjusting tool 18 can be clamped by the holding plates 19 or the screw blades 5 and vertically expanded or contracted according to the internal pressure. desirable.
The adjusting tool 18 and the pressure supply pipe 17 communicate with each other through a joint 22, and the pressure fluid is supplied to the adjusting tool 18 from the pressure supply pipe 17 through the joint 22. As the pressure fluid, known water, air or the like can be used.

In this embodiment, the pipe line 23 is formed inside the screw blade 5, and the pressure supply pipe 17 is inserted into the pipe line 23. The joint 22 is connected to one of the pressure supply pipes 17, and the pressure supply pipe 17 inserted into the screw shaft 6 is connected to the other.

Although the divided adjusters 18 are configured to be connected to both sides of the joint 22, respectively, a known joint such as a joint inserted into an opening formed on the side surface of the adjuster 18 can be used.
Further, the pipe line 23 formed inside the screw blade 5 may be directly used as a part of the pressure supply pipe 17. In that case, the joint 22 is connected to the upper part of the pipe line 23, and the pressure supply pipe 17 inserted into the screw shaft 6 is connected to the lower part of the pipe line 23.
When the thickness of the screw blade 5 is small and the pipe line 23 cannot be formed inside, the screw blade 5 may be cut out from the root to the outer peripheral end at the position of the joint 22 and the pipe material may be separately fixed.

FIG. 7 is a vertical sectional side view of a main part of a screw blade according to another embodiment 3 of the present invention.
A joint 22 for supplying pressure from the outside to the adjuster 18 is projected to either one of the front and rear surfaces of the screw blade 5, and a pressure supply pipe 17 connected to the joint 22 is arranged along the screw blade 5 to the screw shaft 6. ing. This is effective when the thickness of the screw blades 5 is small and is easy to manufacture.

FIG. 8 is a connection diagram of the pressure supply pipe according to the present invention.
In the filtration chamber 10 of the screw press 1, the internal pressure gradually increases from the starting end to the ending end of the screw shaft. In the present embodiment, the screw shaft 6 is divided into a supply zone A, a concentration zone B, a dehydration zone C and a high dehydration zone D from the start end thereof. Adjuster 18 of the scraper 14 is independently for each segment have been arranged to connect, respectively it independent adjustment means 18 pressure supply pipe 17.

The supply zone A is a zone for supplying the stock solution to the filtration chamber 10, and after the stock solution is supplied to the filtration chamber 10 from the supply port 7a, a large amount of the filtrate is separated and discharged from the outer cylinder screen 4. The inside of the supply zone A is low because the dehydrated cake is not filled up to the upper part of the filtration chamber 10. Since the solid content remaining in the filtration chamber 10 contains a large amount of water, a high load is not applied to the scraper 14 fixed to the screw blades 5 of the supply zone A, and the scraper 14 can be easily transported to the next zone. You can

The concentration zone B is a zone in which the water content of the solid matter remaining in the filtration chamber is separated by the outer cylinder screen 4 and conveyed by the screw blades 5. The solid containing a large amount of water, which is transported from the supply zone A, is separated in the concentration zone B by the outer cylinder screen 4. In the concentration zone B, the internal pressure and the degree of concentration of solids are higher than in the supply zone A, and the scraper 14 fixed to the screw blades 5 in the concentration zone B is subjected to a higher load than in the supply zone A.

The dehydration zone C is a zone for separating moisture by applying pressure to the solid content concentrated in the concentration zone B. The solid content is conveyed in a compacted state in the filtration chamber 10 to separate water from the solid content, but the amount of separated water is smaller than that in the concentration zone B. The internal pressure of the dehydration zone C is relatively high, the load applied to the scraper 14 fixed to the screw blades 5 is higher than that of the concentration zone B, and the wear rate of the scraper 14 is faster than that of the concentration zone B.

The high dehydration zone D is a zone where high pressure is applied to separate water from solids. A very high internal pressure is applied due to the reduced internal pressure of the filtration chamber 10 and the back pressure of the pressurizer of the discharge port 11. The force exerted when conveying the compacted solid content having a low water content is large, and the scraper 14 fixed to the screw blades 5 in the high dehydration zone D receives a higher load than that in the dehydration zone C, and the scraper 14 is worn. The speed is faster than dehydration zone C.
The width of each zone can be appropriately set depending on the properties of the stock solution and the specifications of the screw press 1.

When the screw press 1 is operated for a long time, the scraper 14 is worn and does not come into sliding contact with the outer cylinder screen 4, sludge is accumulated on the inner peripheral surface of the outer cylinder screen 4, and the pores are clogged. At that time, pressure is supplied to the adjuster 18 via the pressure supply pipe 17 to move the scraper 14 toward the outer cylinder screen 4, so that the sludge accumulated on the inner peripheral surface of the outer cylinder screen 4 by the scraper 14 is sludge. Can be scraped off to eliminate clogging of pores. On the contrary, if the pressing force of the scraper 14 against the outer cylinder screen 4 is too high, the pressure of the adjusting tool 18 is reduced to move the scraper 14 in the direction of the screw shaft 6 for proper sliding. You can

In particular, when the adjusters 18,... Are arranged independently in each zone and the pressure supply pipes 17,... Are connected to each adjuster 18,. It is possible to move only the scraper 14 in the zone toward the outer cylinder screen 4 by inferring the wear of the scraper 14 from the decrease and supplying the pressure fluid to the adjusting tool 18 in the corresponding zone. By moving only the worn scraper 14 in the direction of the outer cylinder screen 4, it is possible to prevent an increase in the pressing force of the non-worn scraper 14 in the other zones, and prevent an increase in torque due to sliding contact resistance and wear of the scraper 14. ..
By the scraper 14 that is always in sliding contact with an appropriate pressing force, sludge accumulated on the inner peripheral surface of the outer cylinder screen 4 can be removed, and stable solid-liquid separation can be performed.

The scraper 14 provided along the outer peripheral portion of the screw blade 5 may be provided in series from the supply zone A to the high dehydration zone D or may be provided independently in each zone.

The device for preventing clogging of a screw press in the present invention comprises a scraper arranged at the end of a screw blade without disassembling the screw press so as to be movable toward the outer cylinder screen, and a scraper adjusting tool. Are independently provided for each zone of the screw press, so that only the scraper in the worn zone can be moved.
Since it is not necessary to disassemble the screw press to adjust the scraper position on a regular basis, it is also effective for an overhead crane for disassembly and assembly and a relatively small treatment plant that does not have space.
In addition, it is effective for treating sludge containing inorganic sludge and high-hardness sludge that is easily worn, and is also suitable for treating tap water, shells, and shellfish.

4 Outer Cylinder Screen 5 Screw Blade 6 Screw Shaft 14 Scraper 15 Rotary Swivel Joint 17 Pressure Supply Pipe 18 Adjusting Tool 19 Holding Plate

Claims (3)

A screw shaft (6) wound with screw blades (5) is rotatably installed inside the outer cylinder screen (4) to form a filtration chamber (10), and is supplied from one end side of the filtration chamber (10). In the clogging prevention device of the screw press that conveys the sludge that has been dehydrated to the other end while discharging and dehydrating the cake,
A tubular adjusting tool (18) attached to the outer peripheral portion of the screw blade (5) and capable of expanding and contracting according to the internal pressure;
A scraper (14) movable in the direction of the outer cylinder screen (4) according to the expansion and contraction of the adjusting tool (18);
A pressing plate (19) for movably sandwiching the scraper (14) in the direction of the outer cylinder screen (4),
A rotary swivel joint (15) at the end of the screw shaft (6),
A pressure supply pipe (17) inserted into the screw shaft (6), one end of which is connected to the rotary swivel joint (15) and the other end of which is connected to the adjusting tool (18);
The equipped Rutotomoni,
The screw blade (5) is divided into each zone according to the internal pressure of the filtration chamber (10),
Adjusting tool (18) is arranged in each section independently,
A clogging prevention device for a screw press, characterized in that a pressure supply pipe (17,...) Is connected to each adjusting tool (18,... ) . An adjusting tool (18) attached to the outer peripheral end of the screw blade (5),
A scraper (14) adjacent to the outer cylinder screen (4) side of the adjusting tool (18),
Presser plate before and after surface of the screw blade (5) (19, 19) arranged, adjuster (18) and scraper (14) screw press clogging preventing device according to claim 1, characterized in that for holding the .. An adjusting tool (18) attached to an outer peripheral portion of either one of the front and rear surfaces of the screw blade (5),
A scraper (14) adjacent to the outer screen (4) side of the adjusting tool (18),
A pressing plate (19) is arranged outside the surface on which the adjusting tool (18) and the scraper (14) are arranged, and the adjusting tool (18) and the scraper (14) are attached to the screw blade (5) and the pressing plate (19). ), the clogging prevention device of the screw press according to claim 1 .

Images