JP5225190B2 - Screw press-type sludge dewatering device and operation method thereof - Google Patents

Description

  The present invention relates to a screw press type sludge dewatering device for adding a flocculant to a sludge suspension and dewatering agglomerated flocs formed and agglomerated, and a method for operating the same, particularly in sewage treatment plants and various wastewater treatment facilities. When sludge clogging that occurs in the screw press is suppressed and sludge clogging occurs when dewatering the agglomerated sludge produced by adding and mixing polymer flocculant to the sludge The present invention relates to a screw press type sludge dewatering device capable of quickly eliminating a sludge blockage and an operation method thereof.

  Conventionally, a flocculant is added to a suspension such as sludge and the flocs (sludge) obtained by agglomeration are dehydrated with a screw press type sludge dewatering device equipped with a screw press. Sludge dehydration constantly changes with seasonal changes in dewatering environment. When the dewatering process is performed by the screw press under the condition that the dewaterability of the sludge is changed in this way, the water content of the dewatered cake that is dewatered and discharged from the screw press also varies. In the screw press type sludge dewatering device, when the moisture content of the cake in the screw press changes, especially when dehydration proceeds too much and the moisture content becomes very low, the cake adheres to the screw shaft and stays in the screw press. There is a case. The cake fixed to the screw shaft may reduce the amount of dehydrated cake discharged from the cake discharge port by reducing the substantial cake flow path of the screw press, resulting in a decrease in processing speed.

Japanese Patent Laid-Open No. 2005-34774

  In the screw press type sludge dewatering apparatus equipped with the screw press, the screw press is configured so that a screw shaft having a configuration in which screw blades are spirally joined to a rotating shaft inside a normal cylindrical filter body is rotatably arranged. is there. The portion where the tip of the screw blade of the screw shaft is in contact with (or substantially in contact with) the cylindrical filter is always a spiral line on the inner surface of the filter. This spiral contact line is apparently translated in the axial direction as the screw shaft rotates. The solid matter in the filter body moves in the outlet direction with the parallel movement of the spiral contact line. When dehydration of the cake in the screw press progresses and the moisture content decreases and the internal pressure increases, the frictional force and adhesive force generated between both the screw shaft and the filter body of the cake sandwiched between the screw shaft and the filter body are increased. growing.

  At this time, no matter how much frictional force or adhesion force is generated between the cake cake and the cylindrical filter body in the screw press, the cake does not remain stuck inside the filter body. When the “spiral contact line” is rotated to that position, the cake is peeled off by the screw blades. On the other hand, if the frictional force and adhesion force generated between the cake in the screw press and the screw shaft side become excessively large, the cake adheres to the screw shaft and does not move in the screw press. If this state further progresses and all the gaps between the screw shaft and the cylindrical filter body are filled with the cake fixed to the screw shaft side, the inside of the filter body is between the blades of the screw shaft. All of the gaps become like a single cylindrical rod filled with cake, and the cake conveying ability of the screw shaft is completely lost (closed state). This state is called “co-rotation phenomenon”. When this “co-rotation phenomenon” occurs, naturally, the sludge treatment capacity of the screw press type sludge dewatering device is lost.

  In conventional screw press sludge dewatering devices, there is no appropriate method to prevent the co-rotation phenomenon between the screw shaft of the screw press and the cake, and the taper cone is reduced when the moisture content is suppressed or the cake discharge is reduced. If the product is too late, stop the screw press sludge dewatering unit and disassemble the screw press filter. The current situation is to remove the cake adhering to the screw shaft.

  The present invention has been made in view of the above points, and provides a screw press type sludge dewatering device that can be operated without blocking the device while maintaining the dehydrated cake moisture content at a predetermined target moisture content, and an operating method thereof. The purpose is to do.

In order to solve the above-described problems, the present invention includes a screw shaft that is rotatably disposed in a cylindrical filter body and is slidable back and forth in the axial direction relative to the filter body, In the operation method of the screw press-type sludge dewatering device that dehydrates and discharges as a dewatered cake, the radial tip of the screw blade joined to the rotating shaft of the screw shaft is in contact with the filtration surface of the cylindrical filter body or Rotate the screw shaft and slide in the axial direction after setting the shaft rotation speed and the axial slide speed so that the position of the part forming the minute clearance does not move in the axial direction when viewed from the cylindrical filter body. Features.

  Further, the present invention provides a method for operating the screw press sludge dewatering apparatus as described above, wherein a protrusion is provided from at least one location on the filtration surface of the cylindrical filter body into the solid matter movement zone inside the filtration surface as necessary. It is characterized by taking in and out.

In addition, the present invention includes a screw shaft that is rotatably disposed in a cylindrical filter body and is slidable back and forth in the axial direction relative to the filter body. The sludge is dehydrated and discharged as a dehydrated cake. In the screw press type sludge dewatering device, the tip of the radial direction of the screw blade joined to the rotating shaft of the screw shaft is in contact with the filtration surface of the cylindrical filter body or forms a minute clearance . position is characterized by comprising setting means for setting the axial rotational speed and axial sliding speed so as not to move in the axial direction as viewed from the cylindrical filtration member.

  Further, the present invention provides a screw press type sludge dewatering apparatus as described above, wherein protrusions can be freely taken in and out at any timing from at least one place on the filtration surface of the cylindrical filter body into the solids movement zone inside the filtration surface. It is characterized in that it has means for taking in and out the protrusions.

In the present invention, as described above, the position of the portion where the radial tip of the screw blade of the screw shaft contacts or forms a minute clearance with the filtration surface of the cylindrical filter body is viewed from the cylindrical filter body. By setting the shaft rotation speed and the axial slide speed so as not to move in the axial direction, rotating the screw shaft and sliding in the axial direction reduce the frictional force between the screw shaft side and the cake, and move it toward the screw shaft side. The cake that is likely to stick or stick is peeled once to cause a deviation of the sticking surface, and the peeled cake is transferred to the outlet to avoid the “co-rotation phenomenon”. This is because the cake between the blades of the screw blades of the screw shaft retains the frictional force with the cylindrical filter by sliding the screw shaft as if rotating the bolt from the nut and pulling it out. However, the frictional force between the cake and the screw shaft becomes relatively small, which corresponds to the fact that the edge of the portion where the cake and the screw shaft are attached easily breaks.

  Also, this can be done by rotating the screw screwed into the wood with a screwdriver and pulling it out without crushing the screw groove in the wood. This is equivalent to pulling out a rod-like screw in a state where the timber is packed. In other words, the "screw return slide" that is pulled out while rotating along the spiral thread groove is performed on the screw shaft of the screw press, so that the screw shaft can be moved in the axial direction while keeping the cake at the current position as much as possible. It becomes possible, and the edge of the sludge and screw shaft is cut.

  In addition, as described above, the present invention provides a projection by removing the projection from at least one place on the filtration surface of the cylindrical filter body into the solids movement zone inside the filtration surface as necessary. Is driven into the cake in the screw press, creating a large frictional force between the cake in the vicinity of the protrusion and the protrusion, so that the cake that has been rotating together with the screw shaft is pulled by the protrusion to the screw shaft. Peel from the side. At the same time, the screw shaft is slid in the opposite direction of the cake outlet by sliding the screw shaft to the opposite direction of the cake outlet, so that the screw shaft moves away from the cake outlet while leaving the cake between the blades like a screw to be screwed back. Move in the opposite direction. By these operations, the “co-rotation phenomenon” is canceled.

In the present invention, the position of the portion where the radial tip of the screw blade of the screw shaft contacts or forms a small clearance with the filtration surface of the cylindrical filter body moves in the axial direction when viewed from the cylindrical filter body. The screw press mold while maintaining the moisture content of the dehydrated cake at a predetermined value by setting the shaft rotation speed and the axial slide speed of the screw shaft so that the screw shaft rotates and slides in the axial direction. The sludge dewatering apparatus can be quickly released without clogging the sludge dewatering device (without causing the “co-rotation phenomenon” of the cake), and the sludge can be dewatered.

  In addition, the present invention provides a “co-rotation” of the generated cake by inserting and removing protrusions as needed from at least one place on the filtration surface of the cylindrical filter body into the solid material movement zone inside the filtration surface. It is possible to cancel the phenomenon and avoid the phenomenon of cake co-rotation.

It is a figure showing a schematic structure of a screw press type sludge dehydration device concerning the present invention. It is a figure which shows the spin-drying | dehydration operation result of the prior art example of Example (1) and Example 1,2. It is a figure which shows the spin-drying | dehydration driving | operation result of the prior art example of Example (2) and Example 1,2.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a diagram showing a schematic configuration of a screw press type sludge dewatering device provided with a screw press according to the present invention. As shown in the figure, the present screw press type sludge dewatering apparatus includes a screw press 1. The screw press 1 includes a cylindrical filter body 3 and a screw shaft 5 in which screw blades 4 are spirally joined to a rotary shaft 5a. The sludge supply part 2 provided with the hopper 2a into which the sludge 101 is thrown in is provided in the one end part of the filter body 3, and the dewatering cake discharge port 6 in which the dewatering cake 102 is discharged is provided in the other end part of the filter body 3. Yes. The rotating shaft 5a of the screw shaft 5 is a shaft whose shaft diameter is increased at a certain inclination angle toward the dewatered cake discharge port 6. A tapered cone 7 concentric with the rotating shaft 5a is provided at the end of the rotating shaft 5a of the screw shaft 5 on the side of the dewatering cake discharge port 6. In addition, the hatched part in the figure is the plug zone 12 without the screw blades 4.

  Reference numeral 9 denotes a drive device for rotating the screw shaft 5. The rotational drive force of the drive device 9 is transmitted to the rotary shaft 5a of the screw shaft 5 through a sprocket and a chain (not shown). 10 is a hydraulic drive device (hydraulic cylinder) for sliding the screw shaft 5 in the axial direction, and 11 is a taper cone drive device for moving the taper cone 7 in the arrow C direction to open and close. The screw shaft 5 is disposed in the filter body 3 and is rotated by receiving the rotational force from the driving device 9 and further slides as indicated by arrows A and B by receiving the sliding force of the hydraulic driving device 10. It is supposed to be.

In the screw press-type sludge dewatering device having the above-described configuration, the sludge 101 is pressed by the rotating screw blades 4 by rotating the screw shaft 5 by the drive device 9 and supplying the sludge 101 to the hopper 2a of the sludge supply section 2. The filter body 3 and the screw blade 4 move toward the dehydrated cake discharge port 6 while receiving a compressive force. Due to this compressive force, the liquid in the sludge 101 becomes the dehydrated filtrate 103 and is discharged out of the filter body 3. The sludge (cake) whose moisture content is reduced by this dehydration becomes a dehydrated cake 102 and is discharged out of the screw press 1 from the dehydrated cake discharge port 6. Reference numerals 17 and 18 are pressure gauges for detecting pressures P ₁ and P ₂ at the points X ₁ and X ₂ in the filter body 3.

  Human waste sludge has a relatively high fiber content and high dehydrating property among various sludges. When these sludges are dehydrated with the screw press 1 having the above-described configuration, when the rotational speed is 0.3 rotation / min or less and the opening degree of the dewatered cake discharge port 6 is 50 mm or less, the internal pressure in the machine is 0.5 MPa or more, The moisture content of the dehydrated cake 102 discharged may be 65% or less. When the operation of the screw press type sludge dewatering device is continued under such operating conditions, the cake is blocked in the screw press 1 and the above-mentioned “co-rotation phenomenon” may occur. Once the co-rotation phenomenon occurs, it is difficult to deal with the normal screw press 1, the opening of the dewatering cake discharge port 6 is fully opened, the shaft rotational speed of the screw shaft 5 is greatly increased, and the cleaning process is performed. In many cases, such treatment is performed frequently.

  If the cake stuck in the screw press 1 cannot be discharged even after the above treatment, the only method is to dismantle the screw press 1 itself (remove the filter body 3) and scrape the cake in the screw shaft 5 manually. Absent. Therefore, here, as one means for canceling the “co-rotation phenomenon”, a hydraulic drive device 10 for arbitrarily sliding the screw shaft 5 in the axial direction is provided. By sliding the screw shaft 5 in the axial direction by the hydraulic drive device 10, the cake near the dewatered cake discharge port 6 where the hardest cake layer in the screw press 1 is generated is physically discharged. Yes. Furthermore, the effect of canceling this “co-rotation phenomenon” is enhanced, and further lowering the moisture content of the dehydrated cake and preventing or canceling the “co-rotation phenomenon” are satisfied at the same time.

  In order to peel the cake from the screw shaft 5 when the “co-rotation phenomenon” of the cake does not occur or has occurred, it is necessary to give the screw shaft 5 an operation for reducing the friction between the cake and the screw shaft 5 as much as possible. There is. If the cake sticking or sticking to the screw shaft 5 side peels once and the sticking surface is displaced, the peeled cake is transferred to the dehydrated cake discharge port 6 and the “co-rotation phenomenon” may be released. is there. Therefore, here, the hydraulic drive device 10 causes the screw shaft 5 to move in a predetermined axial section (between the position indicated by the solid line and the position indicated by the dotted line in FIG. 1) in the direction of the dewatering cake discharge port 6 and the direction of the sludge supply unit 2. It is possible to slide in two directions. The sliding operation of the screw shaft 5 can be performed while rotating the screw shaft 5 forward or backward, or in a state where the shaft rotation is stopped.

  Here, the screw blade 4 is spirally welded to the rotating shaft 5a of the screw shaft 5, and the shaft slide speed of the screw shaft 5 can be increased if two conditions of the blade and blade pitch and the shaft rotation speed are determined. By adjusting, it is possible to slide the shaft by the above-mentioned “screw return slide”. By periodically performing this “screw return slide” process, the cake fixed to the screw shaft 5 is peeled once, so the frequency of occurrence of cake blockage (“co-rotation phenomenon”) is greatly reduced. The screw press sludge dewatering device can be operated to reduce the water content without worrying about the “co-rotation phenomenon”.

  For example, if it is necessary to dehydrate urine sludge with a screw press 1 having a diameter of 600 mm and operate the dehydrated cake 102 with a moisture content of less than 70%, once per 2 to 4 hours, or the shaft of the screw shaft 5 When the torque value is 10 to 16 kNm or more, the in-machine pressure (detected pressure of the pressure gauge P1 in FIG. 1) is 400 to 700 kPa or more, and the screw shaft 5 is reciprocated once at an interval of 150 to 400 mm, a “common rotation phenomenon” is generated. In addition, it is possible to continue the operation of the screw press type sludge dewatering apparatus that satisfies the moisture content of the dehydrated cake of 70% or less while maintaining the processing speed of about 250 kg / h.

  In the above example using the screw press 1 having a diameter of 600 mm, when the moisture content of the dehydrated cake 102 is further reduced, for example, when operating to obtain a dehydrated cake 102 having a moisture content of about 60%, By adjusting the length of the plug zone 12 and the opening of the tapered cone 7, the pressure inside the machine becomes 1000 kPa or more and the moisture content is lowered. At this time, the processing speed is reduced due to the “co-rotation phenomenon”. May be seen. In this situation, the protrusion insertion mechanisms (projection insertion / removal mechanisms) 13 and 14 are operated to insert the protrusions 15 and 16 into the cake inside the filter body 3 from the outside of the filter body 3.

  As described above, the “co-rotation phenomenon” occurs when the in-machine cake of the screw press 1 is firmly fixed to the screw shaft 5 side rather than the cylindrical filter body 3, but the in-machine cake is stronger from the filter body 3. If the frictional force can be received, the probability that the edge with the screw shaft 5 side is cut without moving integrally with the screw shaft 5 and moved toward the discharge port is increased. As described above, the protrusions 15 and 16 are inserted into the cake inside the filter body 3 by the protrusion insertion mechanisms 13 and 14, so that the cake near the protrusions 15 and 16 is located between the protrusions 15 and 16. Thus, the cake that has generated a large frictional force and co-rotated with the screw shaft 5 is easily peeled off from the screw shaft 5 so as to be pulled by the protrusions 15 and 16.

  At the same time, the screw shaft 5 is slid in the direction opposite to the dewatering cake outlet 6 by the above-mentioned “screw return slide” by the hydraulic drive device 10, so that the screw shaft 5 is a blade of the screw blade 4 like a screw that has been screwed back. The cake moves between the blade and the blade while moving away from the dewatered cake outlet 6. The “co-rotation phenomenon” generated by these operations is canceled, and the “co-rotation phenomenon” that is likely to occur can be avoided. It is also possible to prevent the “co-rotation phenomenon” in advance by appropriately performing “projection insertion” and “screw return slide” for inserting the projections 15 and 16 according to the timer setting. It is also effective to detect the occurrence of co-rotation and the possibility of occurrence by changing the value of shaft thrust load, etc., and perform the above-mentioned “projection insertion” + “screw return slide” operation when a certain condition is reached. .

  As a method for increasing the frictional force between the inner surface of the cylindrical filter body 3 and the in-machine cake, a measure such as increasing the unevenness of the inner surface of the filter body 3 is conceivable. If the tip of 4 is undulated, or if the clearance between the blade 4 and the screw blade 4 is not increased, the screw shaft 5 is rotated so that the inner surface of the filter body 3 is always scraped (scraped) and cleaned. The tip of the screw shaft 5 (the spiral contact portion approaching the cylindrical filter body 3) is mechanically interfered. Therefore, as a matter of course, if there is a projection on the inner surface of the filter body 3 constantly, it comes into contact with the rotating screw shaft 5 and therefore such a projection cannot always be installed. However, since the screw press type sludge dewatering device has a function of sliding the screw shaft 5 of the screw press 1 in the axial direction by the hydraulic drive device 10, the screw blade 4 is moved by the “screw return slide” as described above. Since the tip can move only in the spiral contact portion, the screw shaft 5 is rotated so as not to interfere with the screw shaft 5 even if a protrusion is present on the inner surface of the other filter body 3. be able to.

  As an example of a specific process, the dehydration proceeds and the pressure in the screw press 1 is increased more than necessary, and the processing speed is reduced due to the “co-rotation phenomenon” (the cake transport efficiency by co-rotation decreases). Is detected) at the plurality of predetermined locations of the filter body 3, and the protrusion insertion mechanisms 13 and 14 installed at the positions are detected. The protrusions 15 and 16 are inserted into the filter body 3 by operating.

It is desirable that the protrusion insertion mechanisms 13 and 14 be installed in an area where the cake is easily solidified. In the case of the screw press 1 having a diameter of 600 mm, the position of 300 mm to 1000 mm from the dewatered cake outlet 6 is desirable. The driving cross-sectional area is desirably 12 cm ² or less, and the insertion depth of the protrusions 15 and 16 is desirably 15 to 70% of the blade height of the screw blade 4. The driven projections 15 and 16 generate a large frictional force with the cake in the machine of the screw shaft 5, and the cake rotating together with the screw shaft 5 is caught by the projections 15 and 16. Peel from 5 side.

  At this time, only rotating the screw shaft 5 causes a problem because the rotating screw blade 4 collides with the projections 15 and 16, but as described above, at the same time as inserting the projections 15 and 16, the screw shaft 5 is moved about. “Screw-back slide” at a slide width of 300 mm causes the screw shaft 5 to move in the axial direction opposite to the dewatered cake outlet 6 while leaving the cake between the blades like a screw that has been screwed back. To do. By these operations, the cake layer fixed or likely to be fixed to the screw shaft 5 side is temporarily disconnected from the screw shaft 5 and the rotation is released.

  After the screw shaft 5 is slid to a position about 300 mm rearward and the projections 15 and 16 inserted into the filter body 3 are returned to the outside of the filter body 3, the screw shaft 5 is now axially moved in the direction of the dehydrated cake outlet 6 The cake layer, which has been fixed by being slid, is immediately conveyed toward the dewatering cake outlet 6 and the “co-rotation phenomenon” is completely cancelled. During this time, the screw shaft 5 can be continuously rotated in the normal direction of rotation, but the cake peeling effect may be enhanced by rotating in the opposite direction depending on the situation.

  Below, an example of the operation result by the experimental plant which actually incorporated the screw press type sludge dewatering device concerning the present invention is explained in detail. In addition, this invention is not restrict | limited at all by this Example. The present embodiment is a screw press type sludge dehydration experimental plant that dehydrates sludge treated in a human waste treatment plant using a tempered material using polyiron and an amphoteric polymer flocculant. This screw press-type sludge dewatering device includes a screw press 1 having a diameter D: 300 mm and L / D: 4 (L: length of screw press, D: diameter of screw press). Since the present screw press type sludge dewatering device has the same equipment configuration as the conventional type screw press type sludge dewatering device when the screw shaft 5 is not slid, the conventional screw press type sludge dewatering device has the screw shaft 5 attached. It was set as the case where it was not made to slide.

  In the first embodiment, the “screw return slide” is operated once every two hours by using the hydraulic drive device 10 of the screw press type sludge dewatering device, or when the shaft torque value reaches 80% of the rated torque. Set. In the second embodiment, the “projection insertion process” + “screw return slide” is operated once every two hours in the same screw press-type sludge dewatering device or when the shaft torque value reaches 95% of the rated torque. Set to. The dehydration operation is performed under the two conditions of cases (1) and (2). Case (1) has a target dehydrated cake moisture content of 70% and a target sludge treatment rate of 60 kg / h. Case (2) has a target dehydrated cake moisture content of 60 %, The target sludge treatment rate was 45 kg / h. The target dewatering cake is adjusted by adjusting the number of rotations of the screw shaft 5 of the screw press type sludge dewatering device, the opening degree of the taper cone 7, the length of the plug zone, etc. in each of the case (1) and the case (2). The operating conditions were determined by adjusting the operating conditions so that the water content and the treatment speed could be achieved simultaneously.

  FIG. 2 shows the results of the dehydration operation of the conventional case (1) and Examples 1 and 2, and FIG. 3 shows the results of the dehydration operation of the conventional example and Examples 1 and 2 of the case (2). Here, Example 1 is a case where there is a “screw return slide” step of the screw shaft 5, and Example 2 is a “projection insertion” step and a “screw return slide” step (“projection” + “screw return”). "Step").

  In case (1), as shown in FIG. 2, the target dehydrated cake moisture content is set to 70% and the target sludge treatment rate is set to 60 kg / h. Generally, the moisture content of the dehydrated cake is increased as the sludge treatment rate is increased. Therefore, it is necessary to reduce the water content under the condition that the sludge treatment rate is 60 kg / h. Low moisture content can be achieved by lowering the rotational speed of the screw shaft 5 and narrowing the opening of the taper cone 7, etc., both of which are accompanied by a decrease in the processing speed, so that both target values are satisfied. It is necessary to set the operating conditions in a well-balanced manner.

  As shown in FIG. 2, in the conventional example, it was difficult to set the moisture content of the dehydrated cake to 70% while maintaining the sludge treatment rate at 60 kg / h. This is because the sludge treatment speed of 60 kg / h could not be secured if the shaft rotational speed of the screw shaft 5 or the opening of the taper cone 7 was decreased in order to reduce the moisture content of the dehydrated cake to 70%. On the other hand, in both Examples 1 and 2, it was possible to satisfy the target values of the moisture content of the dehydrated cake and the sludge treatment speed as average values. This prevents the “co-rotation phenomenon” of the cake by the periodic “screw return slide” process of the screw shaft 5, “insertion of protrusion” and “screw return slide” (“projection” + “screw return”) process. It seems that the sludge treatment speed did not decrease.

  In case (2), as shown in FIG. 3, the target dewatered cake moisture content is 60%, which is lower than in case (1), and the target sludge treatment rate is 45 kg / h, which is smaller than in case (1). . In the conventional example and the example, the rotational speed of the screw shaft 5 and the opening degree of the taber cone 7 were set to be smaller than the case (1) as operating conditions to reduce the moisture content of the dehydrated cake. In the state where the speed was maintained at 45 kg / h, the moisture content of the dehydrated cake decreased only to about 71%.

  On the other hand, in Example 1, dehydration was performed while preventing the “co-rotation phenomenon” of the cake by the screw return slide process, but the moisture content of the dehydrated cake was about 63% under the condition that the sludge treatment speed of 45 kg / h was maintained. Only a drop. On the other hand, in Example 2, it was possible to operate simultaneously satisfying the treatment rate of 45 kg / h and the moisture content of the dehydrated cake of 60%. The cake in the screw press 1 that has become very hard and easily clogged is regularly removed from the machine by the "projection insertion" process and the "screw return slide" ("projection" + "screw return") process. It seems that the water content of the dehydrated cake could be reduced stably without causing a decrease in the sludge treatment rate.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Can be modified. Note that any shape or structure not directly described in the specification and drawings is within the technical scope of the present invention as long as the effects of the present invention are achieved. For example, although the rotary shaft 5a of the screw shaft 5 of the screw press 1 is a shaft having a large shaft diameter at a certain inclination angle toward the dewatering cake discharge port, it may be a shaft having the same shaft diameter.

  The present invention adds sludge generated in a sewage treatment plant and various wastewater treatment facilities to a sludge clogging in the screw press when dewatering with a screw press. It is possible to use a screw press type sludge dewatering device and an operation method thereof that can suppress the sludge blockage quickly when the sludge blockage occurs.

DESCRIPTION OF SYMBOLS 1 Screw press 2 Sludge supply part 3 Filter body 4 Screw blade 5 Screw shaft 6 Dehydrated cake discharge port 7 Taper cone 9 Drive device 10 Hydraulic drive device 11 Tapered cone drive device 12 Plug zone 13 Protrusion insertion mechanism (projection insertion / extraction mechanism)
14 Projection insertion mechanism (projection insertion and removal mechanism)
15 Protrusion 16 Protrusion 17 Pressure gauge 18 Pressure gauge

Claims (4)

A screw press type sludge dewatering system that has a screw shaft that can be rotated in a cylindrical filter body and is slidable back and forth in the axial direction relative to the filter body. In the operation method of the device,
The position of the portion where the radial tip of the screw blade joined to the rotating shaft of the screw shaft is in contact with or forms a minute clearance with the filtration surface of the cylindrical filter body is the cylindrical filter body. An operating method of a screw press type sludge dewatering apparatus, wherein the screw shaft is rotated and axially slid after setting an axial rotation speed and an axial sliding speed so as not to move in the axial direction as viewed from the viewpoint. In the operation method of the screw press type sludge dewatering device according to claim 1,
A method of operating a screw press sludge dewatering apparatus, wherein projections are taken in and out as needed from at least one location on the filtration surface of the cylindrical filter body into a solids movement zone inside the filtration surface. A screw press type sludge dewatering system that has a screw shaft that can be rotated in a cylindrical filter body and is slidable back and forth in the axial direction relative to the filter body. In the device
The position of the portion where the radial tip of the screw blade joined to the rotating shaft of the screw shaft is in contact with or forms a minute clearance with the filtration surface of the cylindrical filter body is the cylindrical filter body. A screw press-type sludge dewatering device comprising setting means for setting the shaft rotation speed and the axial slide speed so as not to move in the axial direction when viewed from the side. In the screw press type sludge dewatering device according to claim 3,
A screw provided with a protrusion / removal means for freely protruding / removing a protrusion at an arbitrary timing from at least one point on the filtration surface of the cylindrical filter body into a solid matter moving zone inside the filtration surface. Press sludge dewatering equipment.

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