A kind of sewage treatment is with spiral sludge dewatering equipment

Abstract

This invention relates to the field of water pollution technology, specifically to a screw press sludge dewatering device for wastewater treatment. It includes a dewatering chamber, and further comprises: a drive shaft rotatably connected between the sludge inlet chamber and the sludge discharge hood; a variable-pitch screw shaft mounted on the drive shaft and located within both the sludge inlet chamber and the dewatering chamber; a sleeve movably fitted onto the drive shaft, with a back pressure plate fixed to its outer wall within the sludge discharge hood, the back pressure plate having a plurality of sludge discharge holes evenly spaced circumferentially; and a fixing ring fixed to the drive shaft and located outside the back pressure plate, with a plug corresponding to each sludge discharge hole fixed on the side of the fixing ring closest to the back pressure plate. This invention, by configuring the sleeve, back pressure plate, sludge discharge holes, fixing ring, plugs, and axial movement mechanism, allows switching between two sludge discharge modes according to sludge characteristics, achieving efficient adaptability of the equipment to different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of water pollution technology, specifically to a screw press sludge dewatering device for wastewater treatment. Background Technology

[0002] With water pollution becoming increasingly severe, screw press sludge dewatering equipment has become one of the core pieces of equipment in the wastewater treatment field due to its advantages such as small footprint, low energy consumption, and strong continuous operation stability. From the treatment of excess sludge in municipal wastewater treatment plants to the disposal of high-concentration sludge from industrial wastewater, screw press dewatering equipment plays an irreplaceable role, effectively reducing sludge volume, reducing subsequent disposal costs, and promoting the recycling and sustainable development of water resources.

[0003] Existing screw press sludge dewatering equipment mainly consists of a screw shaft, a dynamic and static ring stack, a drive system, a feeding device, and a back pressure plate. Its working process is as follows: the sludge to be treated enters the equipment through the feeding device. Driven by the rotation of the screw shaft, the sludge passes through the gradually decreasing gaps between the stacked rings. Water is squeezed out, solid particles are retained, and finally, the sludge cake is discharged through the sludge outlet at the back pressure plate. This equipment achieves continuous pressing and dewatering of sludge through the synergistic action of the screw shaft and the stacked rings. Its compact structure and automated operation greatly improve sludge treatment efficiency.

[0004] Currently, sludge is discharged from the edge of the back pressure plate, and operators can adjust the sludge moisture content by adjusting the gap width of the back pressure plate. Specifically, when the sludge is drier, the gap of the back pressure plate can be appropriately increased; conversely, when the sludge is wetter, the gap can be appropriately decreased. However, this adjustment method has certain drawbacks. For example, for sludge with low water content, while increasing the gap of the back pressure plate can improve the smoothness of sludge discharge, it also weakens the axial pressure inside the equipment. The sludge lacks sufficient squeezing force under the push of the screw shaft, resulting in insufficient water discharge. Secondly, the larger gap also shortens the residence time of sludge between the plates, and some sludge is discharged without being fully squeezed and dewatered, which is equivalent to reducing the effective filtration stroke. To address these shortcomings, we propose a screw press sludge dewatering device for wastewater treatment. Summary of the Invention

[0005] The purpose of this invention is to provide a screw press sludge dewatering device for sewage treatment, which solves the problem mentioned in the background art that the sludge is discharged from the edge of the back pressure plate, making it inconvenient to discharge sludge with different moisture contents.

[0006] This invention is achieved through the following technical solution: a screw press sludge dewatering device for sewage treatment, comprising a dewatering chamber, a sludge inlet chamber fixed on the left outer wall of the dewatering chamber, the sludge inlet chamber communicating with the dewatering chamber; a sludge discharge hood fixed on the right outer wall of the dewatering chamber, and a sludge outlet communicating with the sludge discharge hood on the right side of the dewatering chamber, further comprising:

[0007] A drive shaft is rotatably connected between the sludge inlet chamber and the sludge outlet hood, and the drive shaft is capable of rotating along its own axis.

[0008] A variable pitch screw shaft is mounted on a drive shaft and located inside the sludge inlet chamber and the dewatering chamber;

[0009] A sleeve is movably sleeved on a drive shaft. A back pressure plate located inside a mud discharge hood is fixed on the outer wall of the sleeve. Several mud discharge holes are equally spaced along the circumference of the back pressure plate.

[0010] A fixing ring is fixed on the drive shaft and located on the outside of the back pressure plate. A plug corresponding to each mud discharge hole is fixed on the side of the fixing ring near the back pressure plate.

[0011] An axial moving mechanism is provided inside the drive shaft to drive the sleeve to move along the drive shaft in the direction of the sludge outlet, so that the sludge is discharged from the edge of the back pressure plate or from each sludge discharge hole.

[0012] Optionally, a geared motor is fixed on the outer wall of the sludge discharge hood, and the output end of the geared motor is connected to the drive shaft.

[0013] Optionally, a blocking block is integrally formed on the side of the back pressure plate near the mud outlet, the outer contour of the blocking block is adapted to the mud outlet, and the thickness of the blocking block is greater than the depth of the mud outlet.

[0014] Optionally, the sludge discharge hole is a conical hole, and the plug is a cone adapted to the conical hole; as the back pressure plate moves toward the sludge outlet, the gap between the plug and the sludge discharge hole becomes larger and larger.

[0015] Optionally, the axial movement mechanism includes a mounting cavity disposed within the drive shaft, and an adjusting shaft is rotatably connected within the mounting cavity, the adjusting shaft being coaxially disposed with the drive shaft;

[0016] A first threaded section is provided on the adjusting shaft, and a first nut is screwed onto the first threaded section. Several first connecting rods are fixed circumferentially on the outer ring of the first nut. A first strip hole is provided on the drive shaft for each first connecting rod to pass through. The end of each first connecting rod away from the first nut is fixed to the inner wall of the sleeve.

[0017] Optionally, when the sleeve moves axially along the drive shaft, each of the first strip holes is always located within the inner circumference of the sleeve.

[0018] Optionally, the variable pitch screw shaft includes a cylinder movably sleeved on the drive shaft, and variable pitch screw blades are fixed on the outer wall of the cylinder, the variable pitch screw blades being located inside the sludge inlet chamber and the dewatering chamber.

[0019] Optionally, the adjusting shaft is provided with a second threaded section, and a plurality of second nuts are screwed onto the second threaded section. A plurality of second connecting rods are fixed circumferentially at intervals on the outer ring of each second nut.

[0020] A second strip-shaped hole is provided on the drive shaft for each second connecting rod on the same side to move through, and the end of each second connecting rod away from the second nut is fixed to the inner wall of the shaft cylinder.

[0021] Optionally, the first threaded segment and the second threaded segment have the same direction of rotation, and the pitch ratio of the first threaded segment to the second threaded segment is 1:4 to 1:5.

[0022] Optionally, when the shaft cylinder moves axially along the drive shaft, each of the second strip holes is always located within the inner circumference of the shaft cylinder.

[0023] Compared with the prior art, the present invention provides a screw press sludge dewatering device for sewage treatment, which has the following beneficial effects:

[0024] 1. This invention, through the configuration of a sleeve, back pressure plate, sludge discharge hole, fixing ring, plug, and axial movement mechanism, allows switching between two sludge discharge modes based on sludge characteristics: When processing sludge with high moisture content, the sludge is still discharged from the edge of the back pressure plate, subjected to stronger axial pressure and longer compression time, effectively extending the residence time and filtration stroke of the sludge between the plates, ensuring sufficient water discharge, and significantly improving the dryness of the discharged sludge. Conversely, when processing sludge with low moisture content and a drier texture, the axial movement mechanism drives the plug to disengage from the sludge discharge hole, allowing the sludge to be discharged directly through multiple discharge holes. Compared to traditional edge discharge, this method allows the sludge to avoid the narrow edge channel of the back pressure plate, significantly increasing the sludge discharge channel area and effectively alleviating the problem of axial pressure loss caused by narrow channels.

[0025] 2. The variable-pitch screw shaft of this invention can move axially along the drive shaft. When processing sludge with low moisture content and dry texture, this type of sludge is highly viscous and has poor fluidity, making it prone to accumulating and clogging in narrow channels. In this case, by driving the variable-pitch screw shaft backward along the drive shaft through the axial movement mechanism, the gap between the variable-pitch screw shaft and the sludge outlet can be significantly increased, widening the sludge discharge channel. This design not only greatly reduces the resistance of dry sludge during the discharge process and effectively avoids clogging problems caused by narrow channels, but also, in conjunction with the opening of multiple sludge discharge holes, allows dry sludge to be discharged from the equipment quickly and smoothly, significantly improving sludge discharge efficiency and throughput, and ensuring that the equipment can still operate stably and efficiently under complex working conditions.

[0026] 3. In this invention, the sludge discharge hole is a conical hole, and the plug is a cone adapted to the conical hole. When processing sludge with low moisture content and dry texture, the back pressure plate is driven by the axial moving mechanism to move towards the sludge outlet. The plug and the conical surface of the sludge discharge hole gradually separate, and the gap between them gradually increases, forming a variable cross-section sludge discharge channel that gradually increases in size. This design not only avoids sludge impact caused by instantaneous diameter expansion, but also allows for precise control of the sludge discharge flow rate based on the moving distance of the back pressure plate. Attached Figure Description

[0027] Figure 1 This is an assembly drawing of the present invention;

[0028] Figure 2 This is a state diagram of the sludge with high water content processed according to the present invention;

[0029] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0030] Figure 4 for Figure 2 Enlarged view of point B in the middle;

[0031] Figure 5 This is a state diagram of sludge with low water content processed according to the present invention;

[0032] Figure 6 for Figure 5 Enlarged view of point C in the middle;

[0033] Figure 7 This is a diagram showing the state of mud discharge from the edge of the back pressure plate of the present invention;

[0034] Figure 8 This is a diagram showing the state of mud discharge from the mud discharge hole of the present invention.

[0035] In the diagram: 1. Dewatering chamber; 2. Mud inlet chamber; 3. Mud discharge hood; 4. Mud outlet; 5. Drive shaft; 6. Variable pitch screw shaft; 601. Shaft cylinder; 602. Variable pitch screw blade; 7. Sleeve; 8. Back pressure plate; 9. Mud discharge hole; 10. Fixing ring; 11. Plug; 12. Axial movement mechanism; 121. Mounting cavity; 122. Adjusting shaft; 123. First threaded section; 124. First nut; 125. First connecting rod; 126. First strip hole; 13. Gear motor; 14. Plug; 15. Second threaded section; 16. Second nut; 17. Second connecting rod; 18. Second strip hole. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figures 1 to 8 A screw press sludge dewatering device for wastewater treatment includes a dewatering chamber 1, and a sludge inlet chamber 2 fixed to the left outer wall of the dewatering chamber 1, which is connected to the dewatering chamber 1. It should be noted that a flocculation box is installed outside the dewatering chamber 1, and a stirring mechanism is installed inside the flocculation box. External wastewater is transported to the flocculation box, and PAC solution is added to the flocculation box to fully mix with the water, causing suspended solids and colloidal particles in the water to aggregate and form flocs, creating conditions for subsequent dewatering. The mixture of flocs and wastewater is then transported to the sludge inlet chamber 2 through a pipeline for dewatering treatment. This is existing technology and will not be described in detail here.

[0038] A sludge discharge hood 3 is fixed on the outer right side of the dewatering chamber 1. The lower end of the sludge discharge hood 3 is open, allowing the dewatered sludge to be discharged. A sludge outlet 4, which communicates with the sludge discharge hood 3, is provided on the right side of the dewatering chamber 1, allowing the sludge in the dewatering chamber 1 to be discharged through the sludge outlet 4.

[0039] This embodiment also includes: a drive shaft 5, a variable pitch screw shaft 6, a sleeve 7, a retaining ring 10, and an axial movement mechanism 12.

[0040] Specifically, the drive shaft 5 is rotatably connected between the mud inlet 2 and the mud discharge hood 3, and the drive shaft 5 can rotate along its own axis. In this embodiment, a geared motor 13 is fixed on the outer wall of the mud discharge hood 3. The geared motor 13 is communicatively connected to the main control system in the equipment, and the output end of the geared motor 13 is drive-connected to the drive shaft 5 to drive the drive shaft 5 to rotate along its own axis.

[0041] In addition, the variable pitch screw shaft 6 is mounted on the drive shaft 5 and located inside the sludge inlet hopper 2 and the dewatering hopper 1. Inside the sludge inlet hopper 2, the variable pitch screw shaft 6 is designed with a large pitch to quickly transport sludge and ensure smooth feeding. After entering the dewatering hopper 1, the screw shaft pitch gradually narrows, forming a gradient compression space with the dynamic and static ring stacked plate group, which performs efficient pressing and dewatering of the sludge.

[0042] To facilitate the discharge of sludge with different moisture contents, the following design is proposed:

[0043] The sleeve 7 is movably mounted on the drive shaft 5 and can move axially along the drive shaft 5. When the drive shaft 5 rotates, the sleeve 7 can rotate synchronously with the drive shaft 5. A back pressure plate 8 located inside the sludge discharge hood 3 is fixed on the outer wall of the sleeve 7. Several sludge discharge holes 9 are evenly spaced along the circumference of the back pressure plate 8. The axial movement mechanism 12 is set inside the drive shaft 5 and is used to drive the sleeve 7 to move along the drive shaft 5 towards the sludge outlet 4, so that the sludge is discharged from the edge of the back pressure plate 8 or from each sludge discharge hole 9, which can be selected according to the characteristics of the sludge.

[0044] It is worth mentioning that a block 14 is integrally formed on the side of the back pressure plate 8 near the sludge outlet 4. The outer contour of the block 14 is adapted to the sludge outlet 4, and the thickness of the block 14 is greater than the depth of the sludge outlet 4. When the equipment needs to process dry sludge with low moisture content and chooses to discharge sludge from the sludge discharge hole 9, the axial moving mechanism 12 drives the sleeve 7 and the back pressure plate 8 to move, and the block 14 is embedded into the sludge outlet 4. Since the depth of the block 14 exceeds the sludge outlet 4, it can form a tight physical barrier, completely blocking the path of sludge discharge from the sludge outlet 4, ensuring that the sludge can only be discharged in an orderly manner through the sludge discharge hole 9.

[0045] The fixing ring 10 is fixed to the drive shaft 5 and located on the outside of the back pressure plate 8. On the side of the fixing ring 10 near the back pressure plate 8, there is a plug 11 that corresponds to each sludge discharge hole 9. When the equipment processes sludge with high water content and needs to squeeze the sludge out from the edge of the back pressure plate 8, the plug 11, with its tight fit with the sludge discharge hole 9, completely seals each sludge discharge hole 9, ensuring that the sludge is dehydrated and discharged only through the edge channel of the back pressure plate 8, thereby enhancing the squeezing effect and improving the dryness of the discharged sludge.

[0046] In this embodiment, the sludge discharge hole 9 is a conical hole, and the plug 11 is a cone adapted to the conical hole. When the back pressure plate 8 moves towards the sludge outlet 4, the gap between the plug 11 and the sludge discharge hole 9 gradually increases, forming a variable cross-section sludge discharge channel that gradually increases in size. This design cleverly utilizes fluid mechanics principles. Compared to the traditional straight hole structure, the progressive diameter expansion method can effectively buffer the instantaneous pressure during sludge discharge, avoiding sludge impact caused by sudden changes in the channel. At the same time, operators can flexibly adjust the opening size of the sludge discharge channel by controlling the moving distance of the back pressure plate 8 according to the actual working conditions, thereby achieving precise control of the sludge discharge flow rate.

[0047] Using the above design, when treating sludge with high water content, the sludge is highly fluid but difficult to dewater. In this case, each plug 11 seals the corresponding sludge discharge hole 9, and the sludge is still discharged through the edge of the traditional back pressure plate 8 (e.g., Figure 2 and Figure 4 As shown in the figure, this prolongs the residence time of sludge in the gap between the plates, enhances the dewatering effect, and ensures the dryness of the discharged sludge.

[0048] When processing sludge with low moisture content and a dry texture, which has poor fluidity and is prone to clogging, the axial moving mechanism 12 drives the sleeve 7 to move towards the sludge outlet 4, so that the plug 14 seals the sludge outlet 4. At the same time, the plug 11 disengages from the sludge discharge hole 9, and the sludge can be directly discharged through multiple sludge discharge holes 9 (e.g., Figure 5 , Figure 6 (As shown). This design significantly increases the sludge discharge channel area and reduces sludge discharge resistance, which not only greatly increases the sludge discharge volume, but also avoids the problem of spiral shaft blockage caused by the insufficient sludge discharge width of the back pressure plate 8, and realizes the efficient adaptation of the equipment to different working conditions.

[0049] The axial movement mechanism 12 is described below:

[0050] The axial movement mechanism 12 includes a mounting cavity 121 disposed within the drive shaft 5 for mounting other components. An adjusting shaft 122 is rotatably connected within the mounting cavity 121, and the adjusting shaft 122 is coaxially arranged with the drive shaft 5. One end of the adjusting shaft 122 near the mud inlet 2 extends outside the mud inlet 2, and a handle is fixed at this end. The operator can hold the handle and drive the adjusting shaft 122 to rotate within the mounting cavity 121.

[0051] A first threaded section 123 is provided on the adjusting shaft 122, and a first nut 124 is screwed onto the first threaded section 123. Several first connecting rods 125 are fixed circumferentially at intervals on the outer ring of the first nut 124. A first slotted hole 126 is provided on the drive shaft 5 for each of the first connecting rods 125 to pass through. The end of each first connecting rod 126 away from the first nut 124 is fixed to the inner wall of the sleeve 7. When the adjusting shaft 122 rotates, the sleeve 7 can be moved axially along the drive shaft 5 through the engagement of the first threaded section 123 and the first nut 124.

[0052] It should be noted that when the sleeve 7 moves axially along the drive shaft 5, each of the first strip holes 125 is always located within the inner circumference of the sleeve 7, to prevent sludge from entering the mounting cavity 121 through the first strip holes 125 and affecting the components inside the mounting cavity 121.

[0053] With the above design, when the sludge discharge path needs to be adjusted according to the sludge characteristics, the operator only needs to rotate the adjusting shaft 122. The first threaded section 123 uniquely provided on the adjusting shaft 122 and the first nut 124 sleeved on it form a precise helical transmission mechanism. As the adjusting shaft 122 rotates, the first nut 124 is constrained by the threaded pair, converting the rotational motion into linear motion along the axis of the adjusting shaft 122. Since the first nut 124 is connected to the sleeve 7 through the first connecting rod 125, it drives the sleeve 7 to move along the axial direction of the drive shaft 5.

[0054] During the movement, the displacement of the sleeve 7 directly controls the relative position of the back pressure plate 8 and the plug 11: when the sleeve 7 moves away from the sludge outlet 4, the plug 11 gradually embeds into the sludge discharge hole 9 of the back pressure plate 8, forming a tight seal. At this time, the sludge can only be squeezed out from the edge channel of the back pressure plate 8, which is suitable for deep dewatering of sludge with high moisture content. Conversely, when the sleeve 7 moves towards the sludge outlet 4, the conical fit between the plug 11 and the sludge discharge hole 9 gradually separates, the sludge discharge hole 9 is opened, and the sludge can be quickly discharged through multiple sludge discharge holes 9, effectively meeting the high-efficiency treatment needs of dry sludge with low moisture content.

[0055] In another embodiment of this application, the variable-pitch screw shaft 6 includes a cylinder 601 movably sleeved on the drive shaft 5. A variable-pitch screw blade 602 is fixed to the outer wall of the cylinder 601, and the variable-pitch screw blade 602 is located within the sludge inlet chamber 2 and the dewatering chamber 1. Within the sludge inlet chamber 2, the screw pitch is relatively large, enabling rapid sludge transport with low propulsion resistance, ensuring a smooth and efficient feeding process. As the screw blade extends into the dewatering chamber 1, the screw pitch gradually narrows, forming a gradient compression space. In this region, the variable-pitch screw blade 602 closely cooperates with the dynamic and static ring stacked blades, applying continuously increasing compressive force to the sludge, gradually squeezing out the water from the sludge.

[0056] In this embodiment, the adjusting shaft 122 is provided with a second threaded section 15, and a plurality of second nuts 16 are screwed onto the second threaded section 15. A plurality of second connecting rods 17 are fixed circumferentially at intervals on the outer ring of each second nut 16. A second slotted hole 18 is provided on the drive shaft 5 for each second connecting rod 17 on the same side to pass through. The end of each second connecting rod 17 away from the second nut 16 is fixed to the inner wall of the shaft cylinder 601. When the operator rotates the adjusting shaft 122, the second nuts 16 move linearly along the second threaded section 15. Through the rigid transmission of the second connecting rods 17, the shaft cylinder 601 can be driven to move in the axial direction of the drive shaft 5.

[0057] With the above design, when dealing with dry sludge that is poorly fluid and prone to clogging, the operator only needs to rotate the adjusting shaft 122. Through the helical transmission of the second threaded section 15 and the second nut 16, multiple sets of second connecting rods 17 are driven to move synchronously. These connecting rods transmit linear motion to the shaft cylinder 601, causing the variable pitch screw shaft 6 to move along the drive shaft 5 in a direction away from the sludge outlet 4, thereby significantly increasing the distance between the variable pitch screw shaft 6 and the sludge outlet 4.

[0058] The increased spacing effectively widens the discharge channel for dry sludge, creating a larger capacity. This not only provides ample path for sludge transport but also reduces excessive compression of the sludge by decreasing the squeezing resistance between the screw shaft and the discharge port 4. Compared to traditional equipment where narrow channels cause sludge adhesion and accumulation, this design allows the sludge to maintain its original shape more easily within a relatively spacious environment, preventing the formation of highly viscous lumps that clog the channel due to excessive compression. Simultaneously, the reduced squeezing effect, combined with the open discharge port 9, allows the sludge to be discharged more smoothly from the equipment under the combined action of gravity and screw propulsion, significantly improving sludge processing efficiency, reducing the risk of shaft blockage, and fully demonstrating intelligent adaptability to complex operating conditions.

[0059] It is worth mentioning that the first threaded section 123 and the second threaded section 15 have the same direction of rotation, and the pitch ratio between the first threaded section 123 and the second threaded section 15 is 1:4 to 1:5. This identical thread direction allows the operator to simultaneously move the sleeve 7 and the variable pitch screw shaft 6 by rotating the adjusting shaft 122 in only one direction. For example, when the adjusting shaft 122 is rotated clockwise, the first threaded section 123 moves the sleeve 7 towards the mud outlet 4, switching to the mud discharge mode of the mud discharge hole 9; simultaneously, the second threaded section 15 drives the variable pitch screw shaft 6 away from the mud outlet at a faster speed, increasing the clearance of the mud discharge channel. This "co-directional linkage" mechanism avoids the complex operating logic caused by opposite thread directions, significantly reduces the risk of operational errors, and improves the ease of use of the equipment.

[0060] The 1:4 to 1:5 pitch ratio setting cleverly balances the response speed of sludge discharge mode switching and channel gap adjustment. Since the pitch of the second thread section 15 is 4 to 5 times that of the first thread section 123, the axial displacement of the variable pitch screw shaft 6 will be significantly greater than the displacement of the sleeve 7. This means that when switching to the sludge discharge mode of the sludge discharge hole 9 (processing dry sludge with low moisture content), the change in the gap between the back pressure plate 8 and the plug 11 and the widening of the channel of the variable pitch screw shaft 6 can form a dynamic match: when the sludge discharge hole 9 is just opened, the variable pitch screw shaft 6 has already moved far away from the sludge discharge port 4, thus building a spacious sludge discharge channel in advance and avoiding the accumulation of dry sludge at the channel contraction point; conversely, when processing sludge with high moisture content, a small pitch difference can achieve precise fine adjustment of the edge gap of the back pressure plate 8, ensuring stable dewatering pressure.

[0061] In addition, when the shaft cylinder 601 moves along the axial direction of the drive shaft 5, each of the second strip holes 18 is always located in the inner circumference of the shaft cylinder 601, which can prevent sludge from entering the mounting cavity 121 through the second strip holes 18 and affecting the components in the mounting cavity 121.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A stacked screw sludge dewatering device for sewage treatment, comprising a dewatering bin, a sludge inlet bin is fixed on the left side outer wall of the dewatering bin, and the sludge inlet bin is communicated with the dewatering bin; a sludge discharge cover is fixed on the right side outer wall of the dewatering bin, and a sludge outlet is formed in the right side of the dewatering bin and communicated with the sludge discharge cover, characterized in that, Also include: Drive shaft, the drive shaft is rotatably connected between the mud bin and the mud cover, the drive shaft can rotate along its axis; Variable pitch screw shaft, the variable pitch screw shaft is arranged on the drive shaft and located in the mud bin and the dehydration bin; Sleeve, the sleeve is movably sleeved on the drive shaft, a back pressure plate located in the mud cover is fixed on the outer wall of the sleeve, a plurality of mud discharge holes are evenly arranged on the back pressure plate in the circumferential direction; The fixed ring is fixed on the drive shaft and located outside the back pressure plate, and a plug corresponding to each mud discharge hole is fixed on one side of the fixed ring close to the back pressure plate; The axial movement mechanism is arranged in the drive shaft, which is used for driving the sleeve to move along the drive shaft to the sludge outlet direction, so that the sludge is discharged from the edge of the back pressure plate or from each mud discharge hole; The back pressure plate is integrally formed with a plug close to the sludge outlet side, the outer contour of the plug is adapted to the sludge outlet, and the thickness of the plug is greater than the depth of the sludge outlet; The axial movement mechanism includes a mounting cavity arranged in the drive shaft, and the adjusting shaft is rotatably connected in the mounting cavity and coaxially arranged with the drive shaft; A first threaded section is arranged on the adjusting shaft, a first nut is spirally matched on the first threaded section, a plurality of first connecting rods are fixed on the outer ring of the first nut in the circumferential direction, and a first slot is formed on the drive shaft for each first connecting rod to pass through, and the ends of the first connecting rods away from the first nut are fixed to the inner wall of the sleeve; The variable pitch screw shaft includes a shaft cylinder movably sleeved on the drive shaft, and the variable pitch screw blade is fixed on the outer wall of the shaft cylinder and located in the mud bin and the dehydration bin; A second threaded section is arranged on the adjusting shaft, and a plurality of second nuts are spirally matched on the second threaded section, and a plurality of second connecting rods are fixed on the outer ring of each second nut in the circumferential direction; A second slot is formed on the drive shaft for the same side of each second connecting rod to movably pass through, and the ends of each second connecting rod away from the second nut are fixed to the inner wall of the shaft cylinder; The rotation directions of the first threaded section and the second threaded section are the same, and the pitch ratio of the first threaded section to the second threaded section is 1:4-1:

5.

2. The MBR equipment according to claim 1, characterized in that: The outer side wall of the mud cover is fixed with a speed reducer, and the output end of the speed reducer is in transmission connection with the drive shaft.

3. The MBR equipment according to claim 1, characterized in that: The mud discharge hole is a tapered hole, and the plug is a cone adapted to the tapered hole; when the back pressure plate moves towards the sludge outlet, the gap between the plug and the mud discharge hole becomes larger and larger.

4. The MBR equipment according to claim 1, characterized in that: When the sleeve moves along the axis of the drive shaft, each first slot is always located in the inner periphery of the sleeve.

5. The MBR equipment according to claim 1, characterized in that: When the shaft cylinder moves along the axis of the drive shaft, each second slot is always located in the inner periphery of the shaft cylinder.

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