Stacked spiral sludge dewatering equipment for sewage treatment

Abstract

The invention relates to the technical field of water pollution, in particular to stacked spiral sludge dewatering equipment for sewage treatment, which comprises a dewatering bin and further comprises a driving shaft rotatably connected between a sludge inlet bin and a sludge discharge cover; the variable-pitch screw shaft is arranged on the driving shaft and is positioned in the sludge feeding bin and the dewatering bin; the driving shaft is movably sleeved with the sleeve, a back pressure plate located in the sludge discharge cover is fixed to the outer wall of the sleeve, and a plurality of sludge discharge holes are formed in the back pressure plate in the circumferential direction at equal intervals; and the fixing ring is fixed on the driving shaft and located on the outer side of the back pressure plate, and plugs corresponding to the sludge discharge holes one to one are fixed on the side, close to the back pressure plate, of the fixing ring. By arranging the sleeve, the back pressure plate, the sludge discharge hole, the fixing ring, the plug and the axial moving mechanism, two sludge discharge modes can be switched according to sludge characteristics, and efficient adaptation of equipment to different working conditions is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of water pollution, in particular to a screw stack type sludge dewatering device for sewage treatment. Background Art

[0002] As water pollution control becomes increasingly challenging, spiral stack sludge dewatering equipment, with its advantages of small footprint, low energy consumption, and strong continuous operational stability, has become a core piece of equipment in the wastewater treatment industry. From treating excess sludge in municipal wastewater treatment plants to disposing of high-concentration sludge generated by industrial wastewater, spiral stack dewatering equipment plays an irreplaceable role, effectively reducing sludge volume and subsequent disposal costs, thereby promoting the recycling and sustainable development of water resources. Existing screw-type sludge dewatering equipment primarily consists of a screw shaft, a dynamic and static ring stack, a drive system, a feed device, and a back pressure plate. The process works as follows: sludge to be treated enters the equipment through the feed device. Driven by the rotation of the screw shaft, the sludge passes through the gaps between the stacks, which have a gradually decreasing pitch. Water is squeezed out, solid particles are trapped, and the sludge cake is finally discharged through the mud outlet on the back pressure plate. Through the synergistic effect of the screw shaft and the stack, this equipment achieves continuous sludge compression and dewatering. Its compact structure and automated operation significantly improve sludge treatment efficiency. At present, sludge is discharged from the edge of the back pressure plate, and the staff can adjust the humidity of the discharged sludge by adjusting the gap width of the back pressure plate. Specifically, when the discharged sludge is drier, the gap of the back pressure plate can be appropriately increased; conversely, when the discharged sludge is wet, the gap of the back pressure plate can be appropriately reduced. However, this adjustment method has certain drawbacks. For example, for sludge with low water content, although the smoothness of the sludge discharge can be improved by increasing the gap of the back pressure plate, it will also cause the axial pressure inside the equipment to weaken. The sludge lacks sufficient extrusion force under the push of the spiral shaft, resulting in the inability to fully discharge the water. Secondly, the larger gap also shortens the residence time of the sludge between the stacking plates, and some sludge is discharged without being fully squeezed and dehydrated, which is equivalent to reducing the effective filtration stroke. To this end, we proposed a spiral stacking sludge dewatering equipment for sewage treatment to effectively solve the above-mentioned drawbacks. Summary of the Invention

[0003] The purpose of the present invention is to provide a screw stack sludge dewatering equipment for sewage treatment, which is used to solve the problem in the prior art proposed in the above background technology that sludge is discharged from the edge of the back pressure plate, which is inconvenient for discharging sludge with different moisture contents.

[0004] The present invention is achieved through the following technical solutions: a spiral stacking sludge dewatering device for sewage treatment, comprising a dewatering bin, a mud inlet bin fixed on the left outer wall of the dewatering bin, the mud inlet bin being in communication with the dewatering bin; a mud discharge cover fixed on the right outer wall of the dewatering bin, a mud outlet in communication with the mud discharge cover being provided on the right side of the dewatering bin, and further comprising: A drive shaft, the drive shaft being rotatably connected between the mud inlet bin and the mud discharge cover, and the drive shaft being capable of rotating along its own axis; A variable pitch screw shaft, which is arranged on the drive shaft and located in the mud inlet bin and the dewatering bin; A sleeve, the sleeve being movably sleeved on the drive shaft, a back pressure plate located in a mud discharge cover being fixed on the outer wall of the sleeve, and a plurality of mud discharge holes being opened on the back pressure plate at equal intervals along the circumference; A fixing ring is fixed on the drive shaft and is located outside the back pressure plate. A plug corresponding to each mud discharge hole is fixed on the side of the fixing ring close to the back pressure plate. The axial movement mechanism is arranged in the driving shaft and is used to drive the sleeve to move along the driving shaft toward the mud outlet, so that the sludge is discharged from the edge of the back pressure plate or from each mud discharge hole.

[0005] Optionally, a reduction motor is fixed on the outer side wall of the mud discharge cover, and the output end of the reduction motor is transmission-connected to the drive shaft.

[0006] Optionally, a blocking block is integrally formed on one side of the back pressure plate close to 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.

[0007] Optionally, 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 toward the mud outlet, the gap between the plug and the mud discharge hole becomes larger and larger.

[0008] Optionally, the axial movement mechanism includes a mounting cavity provided in the driving shaft, an adjusting shaft is rotatably connected in the mounting cavity, and the adjusting shaft is coaxially provided with the driving shaft; A first threaded section is provided on the adjusting shaft, a first nut is screwed on the first threaded section, a plurality of first connecting rods are fixed on the outer ring of the first nut at intervals along the circumferential direction, a first strip hole is provided on the driving shaft for each first connecting rod to pass through one by one, and one end of each first connecting rod away from the first nut is fixed to the inner wall of the sleeve.

[0009] Optionally, when the sleeve moves along the axial direction of the drive shaft, each first strip-shaped hole is always located on the inner periphery of the sleeve.

[0010] Optionally, the variable pitch spiral shaft includes a shaft cylinder movably sleeved on the drive shaft, and variable pitch spiral blades are fixed on the outer wall of the shaft cylinder, and the variable pitch spiral blades are located in the mud inlet bin and the dewatering bin.

[0011] Optionally, the adjusting shaft is provided with a second threaded section, a plurality of second nuts are screwed together on the second threaded section, and a plurality of second connecting rods are fixed to the outer ring of each second nut at intervals along the circumferential direction; A second strip-shaped hole is provided on the driving shaft for each second connecting rod on the same side to movably pass through, and one end of each second connecting rod away from the second nut is fixed to the inner wall of the shaft cylinder.

[0012] Optionally, the first thread segment and the second thread segment have the same rotation direction, and the pitch ratio of the first thread segment to the second thread segment is 1:4 to 1:5.

[0013] Optionally, when the shaft cylinder moves along the axial direction of the drive shaft, each second strip-shaped hole is always located at the inner periphery of the shaft cylinder.

[0014] Compared with the prior art, the present invention provides a screw stack sludge dewatering device for sewage treatment, which has the following beneficial effects: 1. The present invention is equipped with a sleeve, a back pressure plate, a mud discharge hole, a fixed ring, a plug and an axial movement mechanism, which can switch between two mud discharge modes according to the characteristics of the sludge: when treating sludge with a higher water content, the sludge is still discharged from the edge of the back pressure plate, and the sludge is subjected to stronger axial pressure and longer extrusion, which effectively prolongs the residence time of the sludge between the laminations and the filtration stroke, ensuring that the water is fully discharged and significantly improving the dryness of the mud. When treating sludge with a lower water content and a drier texture, the axial movement mechanism drives the plug to disengage from the mud discharge hole, so that the sludge can be discharged directly through multiple mud discharge holes. Compared with traditional edge mud discharge, this method allows the sludge to avoid the narrow back pressure plate edge channel, greatly increases the mud discharge channel area, and effectively alleviates the problem of axial pressure loss caused by the narrow channel.

[0015] 2. The variable pitch screw shaft of the present invention can move axially along the drive shaft. When processing sludge with a low moisture content and a relatively dry texture, such sludge is very likely to accumulate and clog in narrow channels due to its high viscosity and poor fluidity. At this time, the variable pitch screw shaft is driven backward along the drive shaft by the axial movement mechanism, which can significantly increase the gap between the variable pitch screw shaft and the mud outlet, widening the sludge discharge channel. This design not only greatly reduces the resistance of dry sludge during discharge, effectively avoiding blockage problems caused by narrow channels, but also, combined with the opening of multiple mud discharge holes, allows dry sludge to be discharged quickly and smoothly from the equipment, significantly improving mud discharge efficiency and processing capacity, and ensuring that the equipment can still operate stably and efficiently under complex working conditions.

[0016] 3. The mud discharge hole in this invention is a tapered hole, and the plug is a cone that fits the hole. When processing sludge with a low moisture content and a relatively dry texture, the back pressure plate is driven by the axial movement mechanism toward the mud outlet. The plug gradually separates from the conical surface of the mud discharge hole, and the gap between them gradually increases, forming a mud discharge channel with a variable cross-section from small to large. This design not only avoids sludge impact caused by instantaneous diameter expansion, but also allows precise control of the mud discharge flow rate based on the movement distance of the back pressure plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an assembly diagram of the present invention; Figure 2 This is a state diagram of sludge with a high moisture content treated by the present invention; Figure 3 for Figure 2 A magnified schematic diagram of point A in the middle; Figure 4 for Figure 2 A magnified schematic diagram of point B in the middle; Figure 5 This is a state diagram of sludge with low moisture content treated by the present invention; Figure 6 for Figure 5 The enlarged schematic diagram of point C in the middle; Figure 7 This is a state diagram of mud discharge from the edge of the back pressure plate of the present invention; Figure 8 This is a state diagram of mud discharge from the mud discharge hole of the present invention.

[0018] In the figure: 1. Dehydration bin; 2. Mud inlet bin; 3. Mud discharge hood; 4. Mud outlet; 5. Drive shaft; 6. Variable pitch screw shaft; 601. Shaft cylinder; 602. Variable pitch spiral blade; 7. Casing; 8. Back pressure plate; 9. Mud discharge hole; 10. Fixed ring; 11. Plug; 12. Axial moving mechanism; 121. Mounting cavity; 122. Adjusting shaft; 123. First threaded section; 124. First nut; 125. First connecting rod; 126. First strip hole; 13. Reducer motor; 14. Block; 15. Second threaded section; 16. Second nut; 17. Second connecting rod; 18. Second strip hole. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] See also Figures 1 to 8A screw-type sludge dewatering equipment for sewage treatment includes a dewatering bin 1, a sludge inlet bin 2 is fixed on the left outer wall of the dewatering bin 1, and the sludge inlet bin 2 is communicated with the dewatering bin 1. It should be supplemented that a flocculation tank is provided outside the dewatering bin 1, and a stirring mechanism is provided inside the flocculation tank. External sewage is transported to the flocculation tank, and PAC liquid is added to the flocculation tank to be fully mixed with the water body so that the suspended matter and colloidal particles in the water are aggregated to form flocs, creating conditions for subsequent dehydration. The flocs and sewage mixture are then transported to the sludge inlet bin 2 through a pipeline for dewatering. This is a prior art and will not be described in detail here.

[0021] A mud discharge cover 3 is fixed to the right outer wall of the dehydration bin 1. The lower end of the mud discharge cover 3 is open to discharge the dehydrated sludge. A mud outlet 4 is opened on the right side of the dehydration bin 1 and communicates with the mud discharge cover 3. The sludge in the dehydration bin 1 can be discharged through the mud outlet 4.

[0022] This embodiment further includes: a drive shaft 5 , a variable-pitch screw shaft 6 , a sleeve 7 , a fixing ring 10 and an axial movement mechanism 12 .

[0023] Specifically, the drive shaft 5 is rotatably connected between the mud inlet bin 2 and the mud discharge cover 3, and the drive shaft 5 is capable of rotating along its own axis. In this embodiment, a reduction motor 13 is fixed to the outer wall of the mud discharge cover 3. The reduction motor 13 is communicatively connected to the main control system in the equipment. The output end of the reduction motor 13 is transmission-connected to the drive shaft 5, which is used to drive the drive shaft 5 to rotate along its own axis.

[0024] In addition, a variable-pitch screw shaft 6 is mounted on the drive shaft 5 and located within the sludge inlet silo 2 and the dewatering silo 1. Within the sludge inlet silo 2, the variable-pitch screw shaft 6 rapidly conveys the sludge with a larger pitch, ensuring smooth feeding. Upon entering the dewatering silo 1, the screw shaft's pitch gradually narrows, forming a gradient compression space with the dynamic and static ring stacks, effectively squeezing and dewatering the sludge.

[0025] In order to facilitate the discharge of sludge with different moisture contents, the following design is specially developed: Sleeve 7 is movably mounted on drive shaft 5 and is capable of axial movement. When drive shaft 5 rotates, sleeve 7 rotates synchronously with drive shaft 5. A back pressure plate 8, located within mud discharge cover 3, is fixed to the outer wall of sleeve 7. Back pressure plate 8 is provided with a plurality of mud discharge holes 9 spaced evenly along the circumference. An axial movement mechanism 12 is disposed within drive shaft 5 and is used to drive sleeve 7 along drive shaft 5 toward mud outlet 4, discharging sludge from the edge of back pressure plate 8 or from the mud discharge holes 9, depending on the characteristics of the sludge.

[0026] It's worth noting that a block 14 is integrally formed on the side of the back pressure plate 8 near the mud outlet 4. The outer contour of block 14 matches the mud outlet 4, and its thickness is greater than the depth of the mud outlet 4. When the equipment needs to process dry sludge with a low moisture content and chooses to discharge the sludge through the mud outlet 9, the axial movement mechanism 12 drives the sleeve 7 and back pressure plate 8 to move, and block 14 is then embedded in the mud outlet 4. Because the depth of block 14 exceeds the mud outlet 4, it forms a strict physical barrier, completely blocking the sludge's discharge path from the mud outlet 4, ensuring that the sludge can be discharged in an orderly manner only through the mud outlet 9.

[0027] A fixing ring 10 is fixed to the drive shaft 5 and is located outside the back pressure plate 8. A plug 11 corresponding to each mud discharge hole 9 is fixed on the side of the fixing ring 10 close to the back pressure plate 8. When the equipment is processing sludge with high moisture content and mud needs to be squeezed out from the edge of the back pressure plate 8, the plug 11, by virtue of its close fit with the mud discharge hole 9, completely blocks each mud 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 mud dryness.

[0028] In this embodiment, the mud discharge hole 9 is a tapered hole, and the plug 11 is a cone that adapts to the tapered hole. As the back pressure plate 8 moves toward the mud outlet 4, the gap between the plug 11 and the mud discharge hole 9 increases, forming a mud discharge channel with a variable cross-section from small to large. This design cleverly utilizes the principles of fluid mechanics. Compared to the traditional straight hole structure, the progressive expansion method can effectively buffer the instantaneous pressure during sludge discharge and avoid sludge impact caused by sudden changes in the channel. At the same time, the operator can flexibly adjust the opening size of the mud discharge channel by controlling the movement distance of the back pressure plate 8 according to actual working conditions, achieving fine-grained control of the mud discharge flow rate.

[0029] With the above design, when treating sludge with high water content, the sludge has strong fluidity but is difficult to dehydrate. At this time, each plug 11 closes the corresponding sludge discharge hole 9, and the sludge is still discharged through the edge of the traditional back pressure plate 8 (such as Figure 2 and Figure 4 As shown in the figure, the residence time of sludge in the gap between the laminations is prolonged, the squeezing and dehydration effect is enhanced, and the dryness of the discharged sludge is guaranteed.

[0030] When treating sludge with low moisture content and dry texture, its fluidity is poor and it is easy to get clogged. The axial moving mechanism 12 drives the sleeve 7 to move toward the mud outlet 4, so that the blocking block 14 blocks the mud outlet 4. At the same time, the plug 11 is separated from the mud discharge hole 9, and the sludge can be directly discharged through multiple mud discharge holes 9 (such as Figure 5 、 Figure 6 This design significantly increases the mud discharge channel area and reduces the sludge discharge resistance, which not only greatly increases the mud discharge volume but also avoids the problem of screw shaft blockage caused by the back pressure plate 8 having an excessively small mud discharge width, thus achieving efficient adaptation of the equipment to different working conditions.

[0031] The axial movement mechanism 12 is introduced as follows: The axial movement mechanism 12 includes a mounting cavity 121 within the drive shaft 5 for mounting other components. An adjustment shaft 122 is rotatably connected within the mounting cavity 121 and is coaxially arranged with the drive shaft 5. The end of the adjustment shaft 122, located near the mud inlet bin 2, extends outside the mud inlet bin 2 and is secured with a handle. An operator grasps the handle to rotate the adjustment shaft 122 within the mounting cavity 121.

[0032] The adjustment shaft 122 is provided with a first threaded section 123, which is threadably engaged with a first nut 124. A plurality of first connecting rods 125 are circumferentially fixed to the outer ring of the first nut 124. The drive shaft 5 is provided with first strip-shaped holes 126 through which each of the first connecting rods 125 passes. One end of each first connecting rod 126, distal from the first nut 124, is fixed to the inner wall of the sleeve 7. When the adjustment shaft 122 rotates, the first threaded section 123 and the first nut 124 cooperate to drive the sleeve 7 to move axially along the drive shaft 5.

[0033] It should be noted that when the sleeve 7 moves axially along the drive shaft 5 , each first strip hole 125 is always located at the inner periphery of the sleeve 7 , preventing sludge from entering the installation cavity 121 through the first strip holes 125 and affecting the components in the installation cavity 121 .

[0034] With this design, to adjust the sludge discharge path based on sludge characteristics, the operator simply rotates the adjustment shaft 122. The uniquely designed first threaded section 123 on the adjustment shaft 122 and the first nut 124 mounted thereon form a precise screw transmission mechanism. As the adjustment shaft 122 rotates, the first nut 124, constrained by the threaded pair, converts the rotational motion into linear motion along the axis of the adjustment shaft 122. Because the first nut 124 is connected to the sleeve 7 via the first connecting rod 125, it drives the sleeve 7 along the axial direction of the drive shaft 5. During 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 mud outlet 4, the plug 11 gradually embeds into the mud discharge holes 9 of the back pressure plate 8, forming a tight seal. At this time, the sludge can only be squeezed out from the edge channels of the back pressure plate 8, which is suitable for deep dehydration of high-moisture sludge. Conversely, when the sleeve 7 moves toward the mud outlet 4, the conical surface of the plug 11 and the mud discharge holes 9 gradually separate, and the mud discharge holes 9 are opened. The sludge can be quickly discharged through multiple mud discharge holes 9, effectively meeting the demand for efficient treatment of low-moisture dry sludge.

[0035] In another embodiment of the present application, the variable-pitch spiral shaft 6 includes a shaft barrel 601 that is movably mounted on the drive shaft 5. Variable-pitch spiral blades 602 are fixed to the outer wall of the shaft barrel 601. The variable-pitch spiral blades 602 are located within the sludge inlet 2 and the dewatering chamber 1. Within the sludge inlet 2, the pitch is relatively large, enabling rapid sludge transport with low propulsion resistance, ensuring a smooth and efficient feeding process. As the spiral blades extend into the dewatering chamber 1, the pitch gradually narrows, forming a gradient compression space. In this region, the variable-pitch spiral blades 602 closely cooperate with the dynamic and static ring laminations, exerting a continuously increasing extrusion force on the sludge, gradually squeezing out the water contained in the sludge.

[0036] In this embodiment, the adjustment shaft 122 is provided with a second threaded segment 15, which is threadedly engaged with a plurality of second nuts 16. A plurality of second connecting rods 17 are circumferentially fixed to the outer ring of each second nut 16. A second strip-shaped hole 18 is provided in 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, distal from the second nut 16, is fixed to the inner wall of the shaft barrel 601. When the operator rotates the adjustment shaft 122, the second nuts 16 move linearly along the second threaded segment 15. Through the rigid transmission of the second connecting rods 17, the shaft barrel 601 is driven to move axially along the drive shaft 5.

[0037] With this design, when faced with dry sludge, which has poor fluidity and is prone to clogging, the operator simply rotates the adjustment shaft 122. The helical transmission between the second threaded segment 15 and the second nut 16 drives the multiple sets of second connecting rods 17 to move synchronously. These connecting rods transmit linear motion to the shaft barrel 601, causing the variable-pitch screw shaft 6 to move along the drive shaft 5 away from the mud outlet 4, thereby significantly increasing the distance between the variable-pitch screw shaft 6 and the mud outlet 4. The expansion of this spacing effectively widens the discharge channel of dry sludge, forming a larger accommodation space, which not only reserves sufficient paths for the transportation of dry sludge, but also reduces the degree of excessive extrusion of dry sludge by reducing the extrusion resistance between the spiral shaft and the mud outlet 4. Compared with the dry sludge adhesion and accumulation problems caused by narrow channels in traditional equipment, this design makes it easier for dry sludge to maintain its original shape in a relatively loose space, avoiding the formation of highly viscous lumps that block the channel due to excessive compression. At the same time, the appropriately reduced extrusion effect combined with the opening of the mud discharge hole 9 can enable the dry sludge to be discharged from the equipment in a smoother state under the synergistic effect of gravity and spiral propulsion force, greatly improving the dry sludge processing efficiency, reducing the risk of equipment shaft blockage, and fully demonstrating the intelligent adaptability to complex working conditions.

[0038] It is worth mentioning that the first thread segment 123 and the second thread segment 15 have the same rotation direction, and the pitch ratio of the first thread segment 123 to the second thread segment 15 is 1:4 to 1:5. The same thread rotation direction allows the operator to synchronously realize the axial movement of the casing 7 and the variable pitch screw shaft 6 by only rotating the adjustment shaft 122 in one direction. For example, when the adjustment shaft 122 is rotated clockwise, the first thread segment 123 drives the casing 7 to move toward the mud outlet 4 and switches to the mud discharge mode of the mud discharge hole 9; at the same time, the second thread segment 15 drives the variable pitch screw shaft 6 away from the mud outlet at a faster speed, increasing the gap in the mud discharge channel. This "same-direction linkage" mechanism avoids the complex operating logic caused by opposite thread rotation directions, significantly reduces the risk of operating errors, and improves the ease of use of the equipment. The pitch ratio setting of 1:4 to 1:5 cleverly balances the response speed of switching between mud discharge modes and adjusting the channel gap. Because the pitch of the second thread segment 15 is 4 to 5 times that of the first thread segment 123, the axial displacement of the variable-pitch screw shaft 6 is significantly greater than the displacement of the casing 7. This means that when switching to the mud discharge mode of the mud discharge hole 9 (treating dry sludge with low moisture content), the change in the gap between the back pressure plate 8 and the plug 11 and the channel widening of the variable-pitch screw shaft 6 can form a dynamic match: when the mud discharge hole 9 is just opened, the variable-pitch screw shaft 6 has already moved significantly away from the mud discharge port 4, constructing a spacious mud discharge channel in advance and preventing dry sludge from accumulating at the channel contraction point; conversely, when processing high-moisture sludge, the smaller pitch difference allows for precise fine-tuning of the edge gap of the back pressure plate 8, ensuring stable dehydration pressure. In addition, when the shaft cylinder 601 moves axially along the drive shaft 5 , each second strip hole 18 is always located at the inner periphery of the shaft cylinder 601 , which can prevent sludge from entering the installation cavity 121 through the second strip holes 18 and affecting the components in the installation cavity 121 .

[0039] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A screw-type sludge dewatering device for sewage treatment, comprising a dewatering chamber, a mud inlet chamber fixed on the left outer wall of the dewatering chamber, the mud inlet chamber communicating with the dewatering chamber; a mud discharge cover fixed on the right outer wall of the dewatering chamber, a mud outlet communicating with the mud discharge cover being opened on the right side of the dewatering chamber, characterized in that: Also includes: A drive shaft, the drive shaft being rotatably connected between the mud inlet bin and the mud discharge cover, and the drive shaft being capable of rotating along its own axis; A variable pitch screw shaft, which is arranged on the drive shaft and located in the mud inlet bin and the dewatering bin; A sleeve, the sleeve being movably sleeved on the drive shaft, a back pressure plate located in a mud discharge cover being fixed on the outer wall of the sleeve, and a plurality of mud discharge holes being opened on the back pressure plate at equal intervals along the circumference; A fixing ring is fixed on the drive shaft and is located outside the back pressure plate. A plug corresponding to each mud discharge hole is fixed on the side of the fixing ring close to the back pressure plate. The axial movement mechanism is arranged in the driving shaft and is used to drive the sleeve to move along the driving shaft toward the mud outlet, so that the sludge is discharged from the edge of the back pressure plate or from each mud discharge hole.

2. The screw-type sludge dewatering equipment for sewage treatment according to claim 1, characterized in that: A reduction motor is fixed on the outer side wall of the mud discharge cover, and the output end of the reduction motor is transmission-connected to the drive shaft.

3. The screw-type sludge dewatering equipment for sewage treatment according to claim 1, characterized in that: A blocking block is integrally formed on one side of the back pressure plate close to 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.

4. The screw-type sludge dewatering equipment for sewage treatment 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 toward the mud outlet, the gap between the plug and the mud discharge hole becomes larger and larger.

5. The screw-type sludge dewatering equipment for sewage treatment according to claim 1, characterized in that: The axial movement mechanism includes a mounting cavity provided in the driving shaft, an adjusting shaft is rotatably connected in the mounting cavity, and the adjusting shaft is coaxially provided with the driving shaft; A first threaded section is provided on the adjusting shaft, a first nut is screwed on the first threaded section, a plurality of first connecting rods are fixed on the outer ring of the first nut at intervals along the circumferential direction, a first strip hole is provided on the driving shaft for each first connecting rod to pass through one by one, and one end of each first connecting rod away from the first nut is fixed to the inner wall of the sleeve.

6. The screw-type sludge dewatering equipment for sewage treatment according to claim 5, characterized in that: When the sleeve moves along the axial direction of the driving shaft, each first strip-shaped hole is always located at the inner periphery of the sleeve.

7. The screw-type sludge dewatering equipment for sewage treatment according to claim 5, characterized in that: The variable pitch spiral shaft comprises a shaft cylinder movably sleeved on the driving shaft, and variable pitch spiral blades are fixed on the outer wall of the shaft cylinder. The variable pitch spiral blades are located in the mud inlet bin and the dewatering bin.

8. The screw-type sludge dewatering equipment for sewage treatment according to claim 7, characterized in that: The adjusting shaft is provided with a second threaded section, on which a plurality of second nuts are screwed, and on the outer ring of each second nut a plurality of second connecting rods are fixed at intervals along the circumferential direction; A second strip-shaped hole is provided on the driving shaft for each second connecting rod on the same side to movably pass through, and one end of each second connecting rod away from the second nut is fixed to the inner wall of the shaft cylinder.

9. The screw-type sludge dewatering equipment for sewage treatment according to claim 8, characterized in that: The first thread segment and the second thread segment have the same rotation direction, and the pitch ratio of the first thread segment to the second thread segment is 1:4 to 1:

5.

10. The screw-type sludge dewatering equipment for sewage treatment according to claim 8, characterized in that: When the shaft cylinder moves along the axial direction of the driving shaft, each second strip-shaped hole is always located at the inner periphery of the shaft cylinder.

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