A spiral dehydrator

Abstract

The utility model discloses a kind of stacked screw dewatering devices, including stacked screw main body, the stacked screw main body includes the stacked screw body formed by fixed ring and travelling ring interlaced layering and the spiral shaft passing through stacked screw body, spiral pitch is equipped on spiral shaft gradually reduces along sludge conveying direction spiral blade, stacked screw body is sequentially divided into concentration section and dehydration section along sludge conveying direction, spiral shaft located in dehydration section is eccentric shaft, the cross-sectional area of spiral shaft located in dehydration section is greater than the cross-sectional area of spiral shaft located in concentration section.The scheme eccentric shaft and spiral pitch gradually reduce along sludge conveying direction spiral blade cooperation form spiral channel, the instantaneous flow of the spiral channel along sludge conveying direction presents variable and small alternately distribution, internal pressure generated by sludge through spiral channel presents variable or small alternately distribution, improve the problem of local sludge jam in dehydration section by internal pressure difference, prevent local shaft blocking phenomenon in dehydration section after sludge water content reduction in dehydration section.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a screw press dewatering device. Background Technology

[0002] Screw press sludge dewatering machines are widely used for sludge dewatering in various industries such as municipal wastewater, food and beverage, slaughtering and breeding, printing and dyeing, petrochemicals, and papermaking. The working principle of a screw press sludge dewatering machine is based on a stacked screw body formed by alternating fixed and moving rings, with a spiral shaft running through it, forming a filter-driving device. The front end is the thickening section, and the rear end is the dewatering section. The filter gaps between the fixed and moving rings, as well as the screw pitch, gradually decrease from the thickening section to the dewatering section. The rotation of the spiral shaft propels the sludge from the thickening section to the dewatering section while simultaneously driving the moving rings to clean the filter gaps and prevent clogging. After thickening, the sludge is transported to the dewatering section. During its forward movement, as the filter gaps and screw pitch gradually decrease, and under the action of the pressure plates, significant internal pressure is generated, causing the volume to continuously shrink, achieving thorough dewatering. In actual use, due to improper operation or the diverse characteristics of sludge, sludge blockage may occur in certain parts of the dewatering section of the screw press, causing local sludge agglomeration and blockage of the screw shaft, which is then squeezed out from the gap between the ring plates, and the screw press may even be unable to complete the dewatering work normally.

[0003] For example, Chinese Patent Publication No. CN201762228U, published on March 11, 2011, entitled "Easy-to-Maintain Screw Press Sludge Dewatering Machine", includes a base, a screw shaft with helical blades, a motor that drives the screw shaft to rotate, and a filter plate assembly nested around the screw shaft. The filter plate assembly consists of several fan-shaped annular fixed plates and moving plates arranged at axial intervals. The fan-shaped annular fixed plates and moving plates pass through the corresponding support shafts and keep the fixed plates in the same axial longitudinal section symmetrical, and the fixed plates in the same axial longitudinal section form a ring.

[0004] The drawback of the existing patent is that, in actual use, due to improper operation or the diverse characteristics of sludge, sludge blockage occurs in a certain part of the dewatering section of the screw press, causing local sludge agglomeration and blockage of the screw shaft, which is squeezed out from the gap between the ring plates, and the screw press may even fail to complete the dewatering work normally. Utility Model Content

[0005] The purpose of this invention is to improve the problem of sludge blockage in a certain part of the dewatering section of the screw press in the actual use of the existing screw press sludge dewatering machine, which causes local sludge to clump and block the screw shaft and squeeze out from the gap between the ring plates. The invention provides a screw press dewatering device that improves the local shaft blockage in the dewatering section of the screw press.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dewatering device using a screw press includes a screw press body, which comprises a screw body formed by alternating layers of fixed rings and moving rings, and a spiral shaft penetrating the screw press body. The spiral shaft is equipped with spiral blades whose pitch gradually decreases along the sludge conveying direction. The screw press body is divided into a thickening section and a dewatering section along the sludge conveying direction. The spiral shaft located in the dewatering section is an eccentric shaft, and its cross-sectional area is larger than that of the spiral shaft located in the thickening section. In this dewatering device, the screw pitch gradually decreases from the thickening section to the dewatering section, and the cross-sectional area of ​​the spiral shaft in the dewatering section is larger than that in the thickening section. The rotation of the spiral shaft pushes the sludge from the thickening section to the dewatering section, generating significant internal pressure. Macroscopically, the volume continuously decreases, achieving thorough dewatering. In this design, the spiral shaft placed within the dewatering section is an eccentric shaft. The eccentric shaft and spiral blades with gradually decreasing pitch along the sludge conveying direction cooperate to form a spiral channel. The instantaneous flow rate of this spiral channel alternates between increasing and decreasing along the sludge conveying direction. The internal pressure generated by the sludge passing through the spiral channel also alternates between increasing and decreasing, preventing localized shaft blockage in the dewatering section due to reduced sludge moisture content. Driven by the spiral shaft, the sludge undergoes localized dewatering as it passes through a cavity with increased local pressure. After dewatering, it enters a cavity with decreased local pressure, facilitating the spiral shaft and blades to propel the sludge into this lower pressure area. This prevents sludge with lower moisture content from accumulating in areas of higher pressure, causing sludge agglomeration and blockage, and potentially squeezing out from the gaps between the ring blades, or even preventing the screw press from completing its dewatering process properly. The alternating distribution of localized pressure within the dewatering section, driven by the spiral blades, effectively mitigates the problem of localized sludge blockage.

[0008] Preferably, the eccentric shaft located in the dewatering section is divided into a first eccentric shaft and a second eccentric shaft along the sludge conveying direction. The first and second eccentric shafts are coaxially arranged, and the cross-sectional area of ​​the second eccentric shaft is larger than that of the first eccentric shaft. This arrangement causes the cross-sectional area of ​​the spiral shaft to gradually increase in the sludge conveying direction, thereby gradually reducing the volume between the spiral shaft and the stacked screw, achieving the purpose of thorough dewatering.

[0009] Preferably, the eccentric direction of the first eccentric shaft is opposite to that of the second eccentric shaft, the eccentricity of the second eccentric shaft is greater than that of the first eccentric shaft, and the radius of the second eccentric shaft is greater than that of the first eccentric shaft. The opposite eccentricity of the first and second eccentric shafts creates a larger internal pressure difference between them, which helps to alleviate localized sludge blockage within the dewatering section and improves sludge blockage at the rear end of the dewatering section.

[0010] Preferably, the screw press body has a sludge inlet hole and a sludge outlet hole at both ends, and the screw press body is inclined, with the height of the sludge outlet hole being higher than the height of the sludge inlet hole. This allows water to accumulate in the thickening section under its own gravity and be dewatered, reducing the water content of the sludge in the dewatering section.

[0011] Preferably, the main body of the screw press is provided with a pressure plate on the outside of the sludge discharge hole and a pressing mechanism that drives the pressure plate to elastically press against the outside of the sludge discharge hole, with the pressure plate covering the sludge discharge hole. The pressure plate presses against the outside of the sludge discharge hole to better dewater the sludge discharged from the sludge discharge hole and reduce the water content of the sludge discharged from the sludge discharge hole. The pressing mechanism is elastically set to prevent sludge from clogging between the pressure plate and the sludge discharge hole, and can automatically and elastically adjust according to the characteristics of the sludge.

[0012] Preferably, the clamping mechanism includes an elastic element fixed to the main body of the screw press, which drives the pressure plate to press against the outside of the sludge outlet. The elastic element is elastically configured to prevent sludge from clogging between the pressure plate and the sludge outlet, and can automatically adjust elastically according to the characteristics of the sludge.

[0013] Preferably, there are multiple elastic elements, which are evenly distributed circumferentially along the central axis of the spiral shaft. This ensures that the pressure plate is evenly and elastically pressed against the outside of the mud outlet hole.

[0014] Preferably, the length of the thickening section is greater than half the total length of the stacked screw. This allows for sufficient thickening, ensuring that the sludge moisture content is reduced to a certain level before entering the dewatering section for complete dewatering.

[0015] Preferably, the length of the thickening section is less than two-thirds of the total length of the stacked screw. It has a certain dewatering stroke, allowing for thorough dewatering of sludge with a reduced moisture content.

[0016] Preferably, the stacked screw body has a cylindrical cavity, and the helical blades cooperate with the inner wall of the cavity.

[0017] Therefore, this utility model has the following beneficial effects: the pitch of the spiral shaft gradually decreases from the thickening section to the dewatering section, and the cross-sectional area of ​​the spiral shaft in the dewatering section is larger than that of the spiral shaft in the thickening section. The rotation of the spiral shaft pushes the sludge from the thickening section to the dewatering section, generating extremely high internal pressure. Macroscopically, the volume continuously decreases, achieving the purpose of thorough dewatering. The eccentric shaft and the spiral blades with a pitch that gradually decreases along the sludge conveying direction cooperate to form a spiral channel. The instantaneous flow rate of the spiral channel is distributed alternately with increasing and decreasing along the sludge conveying direction. The internal pressure generated by the sludge through the spiral channel is also distributed alternately with increasing and decreasing. The internal pressure difference improves the problem of local sludge blockage in the dewatering section and prevents local shaft blockage in the dewatering section after the sludge moisture content decreases. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention.

[0019] Figure 2 This is a schematic diagram of a spiral shaft in Embodiment 2 of this utility model.

[0020] Figure 3 This is a cross-sectional view of the spiral shaft in Embodiment 2 of this utility model.

[0021] As shown in the picture:

[0022] 1. Main body of the stacked screw press; 1.1 mud inlet hole; 1.2 mud outlet hole;

[0023] 2. Stacked spiral body, 2.1. Concentration section, 2.2. Dehydration section

[0024] 3. Helical shaft, 3.1. First eccentric shaft, 3.2.

[0025] 4. Spiral blade; 5. Pressure plate; 6. Elastic element. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the utility model will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0027] Example 1, as Figure 1 The illustrated dewatering device for a screw press includes a screw press body 1, which comprises a screw press body 2 formed by alternating layers of fixed rings and moving rings, and a spiral shaft 3 penetrating the screw press body 2. The spiral shaft 3 is provided with spiral blades 4 whose pitch gradually decreases along the sludge conveying direction. The screw press body 2 is divided into a thickening section 2.1 and a dewatering section 2.2 along the sludge conveying direction. The spiral shaft 3 located in the dewatering section 2.2 is an eccentric shaft, and the cross-sectional area of ​​the spiral shaft 3 located in the dewatering section 2.2 is larger than that of the spiral shaft 3 located in the thickening section 2.1.

[0028] Screw press sludge dewatering machines are widely used for sludge dewatering in various industries such as municipal wastewater, food and beverage, slaughtering and breeding, printing and dyeing, petrochemicals, and papermaking. The working principle of the screw press sludge dewatering machine is that a screw body 2 is formed by alternating layers of fixed and moving rings, with a spiral shaft 3 passing through it, forming a filter-driving device. The front end is the thickening section, and the rear end is the dewatering section. The filter gaps formed between the fixed and moving rings, as well as the pitch of the spiral shaft 3, gradually decrease from the thickening section to the dewatering section. The rotation of the spiral shaft 3 propels the sludge from the thickening section to the dewatering section while simultaneously driving the moving rings to clean the filter gaps and prevent clogging. After thickening, the sludge is transported to the dewatering section. During its forward movement, as the filter gaps and spiral pitch gradually decrease, and under the action of the pressure plate 5, a great deal of internal pressure is generated, causing the volume to continuously shrink, achieving the purpose of thorough dewatering. In actual use, due to improper operation or the diverse characteristics of sludge, sludge blockage occurs in a certain part of the dewatering section 2.2 of the screw press 2, causing local sludge agglomeration and blockage of the screw shaft 3, which is squeezed out from the gap between the ring plates, and even the screw press cannot complete the dewatering work normally.

[0029] To address the issue of sludge blockage in a certain part of the dewatering section 2.2 of the screw press sludge dewatering machine during actual use, which causes localized sludge agglomeration and blockage of the screw shaft 3 and its extrusion from the gaps between the ring plates, a screw press dewatering device is provided to improve the localized shaft blockage in the dewatering section 2.2 of the screw press 2.

[0030] In this design, a screw press dewatering device features a screw shaft 3 with a gradually decreasing pitch from the thickening section 2.1 to the dewatering section 2.2. The cross-sectional area of ​​the screw shaft 3 within the dewatering section 2.2 is larger than that within the thickening section 2.1. The rotation of the screw shaft 3 propels the sludge from the thickening section 2.1 to the dewatering section 2.2, generating significant internal pressure. Macroscopically, the volume continuously decreases, achieving thorough dewatering. In this design, the screw shaft 3 within the dewatering section 2.2 is an eccentric shaft. The eccentric shaft and the screw blades 4 with a gradually decreasing pitch along the sludge conveying direction form a spiral channel. The instantaneous flow rate of the spiral channel alternates between increasing and decreasing along the sludge conveying direction. The internal pressure generated by the sludge passing through the spiral channel also alternates between increasing and decreasing, preventing localized shaft blockage within the dewatering section 2.2 after the sludge's moisture content decreases. Driven by the screw shaft 3, the sludge undergoes localized dewatering as it passes through a cavity with increased local pressure. After dewatering, it enters a cavity with decreased local pressure, facilitating the screw shaft 3 and screw blades 4 to propel the sludge into this reduced-pressure area. This prevents sludge with lower water content from clogging in areas of higher pressure, causing sludge agglomeration and blockage, and potentially squeezing out from the gaps between the ring blades, which could even prevent the screw press from completing its dewatering process properly. The local pressure within the dewatering section 2.2 alternates between increasing and decreasing, which, driven by the screw blades 4, effectively mitigates the problem of localized sludge blockage.

[0031] Specifically, such as Figure 1 As shown, the main body 1 of the screw press has a mud inlet 1.1 and a mud outlet 1.2 at its two ends. The main body 1 is inclined, and the height of the mud outlet 1.2 is higher than the height of the mud inlet 1.1. This is to allow water to accumulate in the thickening section 2.1 under its own gravity and be dewatered, thereby reducing the water content of the sludge in the dewatering section 2.2.

[0032] The concentrator 2 was further optimized, with the length of the thickening section 2.1 being greater than half the total length of the concentrator 2. This allows for sufficient thickening, ensuring that the sludge moisture content is reduced to a certain level before entering the dewatering section 2.2 for complete dewatering.

[0033] The concentrator 2 was further optimized, with the length of the thickening section 2.1 being less than two-thirds of the total length of the concentrator 2. This allows for a certain dewatering process, enabling the sludge with reduced moisture content to a sufficient level for thorough dewatering.

[0034] The stacked screw body 2 is further optimized. The stacked screw body 2 has a cylindrical cavity inside, and the spiral blade 4 fits into the inner wall of the cavity.

[0035] Example 2, as Figure 1 , Figure 2 , Figure 3 The illustrated dewatering device for a screw press includes a screw press body 1, which comprises a screw press body 2 formed by alternating layers of fixed rings and moving rings, and a spiral shaft 3 penetrating the screw press body 2. The spiral shaft 3 is provided with spiral blades 4 whose pitch gradually decreases along the sludge conveying direction. The screw press body 2 is divided into a thickening section 2.1 and a dewatering section 2.2 along the sludge conveying direction. The spiral shaft 3 located in the dewatering section 2.2 is an eccentric shaft, and the cross-sectional area of ​​the spiral shaft 3 located in the dewatering section 2.2 is larger than that of the spiral shaft 3 located in the thickening section 2.1.

[0036] In this embodiment, as Figure 1 , Figure 2 , Figure 3 As shown, the eccentric shaft located in the dewatering section 2.2 is sequentially divided into a first eccentric shaft 3.1 and a second eccentric shaft 3.2 along the sludge conveying direction. The first eccentric shaft 3.1 and the second eccentric shaft 3.2 are coaxially arranged, and the cross-sectional area of ​​the second eccentric shaft 3.2 is larger than that of the first eccentric shaft 3.1. This arrangement ensures that the cross-sectional area of ​​the spiral shaft 3 gradually increases in the sludge conveying direction, thereby gradually reducing the volume between the spiral shaft 3 and the stacked screw body 2, achieving the purpose of thorough dewatering.

[0037] The first eccentric shaft 3.1 and the second eccentric shaft 3.2 are further optimized. The eccentric direction of the first eccentric shaft 3.1 is opposite to that of the second eccentric shaft 3.2, the eccentricity of the second eccentric shaft 3.2 is greater than that of the first eccentric shaft 3.1, and the radius of the second eccentric shaft 3.2 is greater than that of the first eccentric shaft 3.1. The opposite eccentric direction of the first eccentric shaft 3.1 and the second eccentric shaft 3.2 creates a larger internal pressure difference between them. This larger internal pressure difference improves the problem of localized sludge blockage in the dewatering section 2.2 and also improves the sludge blockage problem at the rear end of the dewatering section 2.2.

[0038] Specifically, the main body 1 of the screw press has a mud inlet 1.1 and a mud outlet 1.2 at its two ends. The main body 1 is inclined, and the height of the mud outlet 1.2 is higher than the height of the mud inlet 1.1. This is to allow water to accumulate in the thickening section 2.1 under its own gravity and be dewatered, thereby reducing the water content of the sludge in the dewatering section 2.2.

[0039] The concentrator 2 was further optimized, with the length of the thickening section 2.1 being greater than half the total length of the concentrator 2. This allows for sufficient thickening, ensuring that the sludge moisture content is reduced to a certain level before entering the dewatering section 2.2 for complete dewatering.

[0040] The concentrator 2 was further optimized, with the length of the thickening section 2.1 being less than two-thirds of the total length of the concentrator 2. This allows for a certain dewatering process, enabling the sludge with reduced moisture content to a sufficient level for thorough dewatering.

[0041] The stacked screw body 2 is further optimized. The stacked screw body 2 has a cylindrical cavity inside, and the spiral blade 4 fits into the inner wall of the cavity.

[0042] In the above embodiment, the pitch of the spiral shaft 3 gradually decreases from the thickening section 2.1 to the dewatering section 2.2, and the cross-sectional area of ​​the spiral shaft 3 in the dewatering section 2.2 is larger than that in the thickening section 2.1. The rotation of the spiral shaft 3 pushes the sludge from the thickening section 2.1 to the dewatering section 2.2, generating extremely high internal pressure. Macroscopically, the volume continuously decreases, achieving the purpose of thorough dewatering. The eccentric shaft and the spiral blades 4 with the pitch gradually decreasing along the sludge conveying direction cooperate to form a spiral channel. The instantaneous flow rate of the spiral channel alternates between increasing and decreasing along the sludge conveying direction. The internal pressure generated by the sludge through the spiral channel also alternates between increasing and decreasing. The internal pressure difference improves the problem of local sludge blockage in the dewatering section 2.2 and prevents local shaft blockage in the dewatering section 2.2 after the sludge moisture content decreases.

[0043] Example 3, as Figure 1 , Figure 2 , Figure 3The illustrated dewatering device for a screw press includes a screw press body 1, which comprises a screw press body 2 formed by alternating layers of fixed rings and moving rings, and a spiral shaft 3 penetrating the screw press body 2. The spiral shaft 3 is provided with spiral blades 4 whose pitch gradually decreases along the sludge conveying direction. The screw press body 2 is divided into a thickening section 2.1 and a dewatering section 2.2 along the sludge conveying direction. The spiral shaft 3 located in the dewatering section 2.2 is an eccentric shaft, and the cross-sectional area of ​​the spiral shaft 3 located in the dewatering section 2.2 is larger than that of the spiral shaft 3 located in the thickening section 2.1.

[0044] In this embodiment, as Figure 1 , Figure 2 , Figure 3 As shown, the main body 1 of the screw press is equipped with a pressure plate 5 and a pressing mechanism that elastically presses the pressure plate 5 against the outside of the sludge outlet 1.2. The pressure plate 5 covers the sludge outlet 1.2. The pressure plate 5 presses against the outside of the sludge outlet 1.2 to better dewater the sludge discharged from the sludge outlet 1.2 and reduce the water content of the sludge discharged from the sludge outlet 1.2. The pressing mechanism is elastically set to prevent sludge from clogging between the pressure plate 5 and the sludge outlet 1.2, and can automatically and elastically adjust according to the characteristics of the sludge.

[0045] The pressing mechanism has been further optimized. The pressing mechanism includes an elastic element 6 fixed on the main body 1 of the screw press. The elastic element 6 drives the pressure plate 5 to press against the outside of the sludge outlet hole 1.2. The elastic element 6 is elastically set to prevent sludge from clogging between the pressure plate 5 and the sludge outlet hole 1.2, and can automatically adjust elastically according to the characteristics of the sludge.

[0046] The elastic element 6 is further optimized by having multiple elastic elements 6, which are evenly distributed circumferentially along the central axis of the spiral shaft 3. This ensures that the pressure plate 5 is evenly and elastically pressed against the outside of the mud outlet hole 1.2.

[0047] The eccentric shaft within the dewatering section 2.2 is further optimized. Along the sludge conveying direction, the eccentric shaft is divided into a first eccentric shaft 3.1 and a second eccentric shaft 3.2, which are coaxially arranged. The cross-sectional area of ​​the second eccentric shaft 3.2 is larger than that of the first eccentric shaft 3.1. This arrangement ensures that the cross-sectional area of ​​the spiral shaft 3 gradually increases along the sludge conveying direction, thereby gradually reducing the volume between the spiral shaft 3 and the stacked screw 2, achieving thorough dewatering.

[0048] The first eccentric shaft 3.1 and the second eccentric shaft 3.2 are further optimized. The eccentric direction of the first eccentric shaft 3.1 is opposite to that of the second eccentric shaft 3.2, the eccentricity of the second eccentric shaft 3.2 is greater than that of the first eccentric shaft 3.1, and the radius of the second eccentric shaft 3.2 is greater than that of the first eccentric shaft 3.1. The opposite eccentric direction of the first eccentric shaft 3.1 and the second eccentric shaft 3.2 creates a larger internal pressure difference between them. This larger internal pressure difference improves the problem of localized sludge blockage in the dewatering section 2.2 and also improves the sludge blockage problem at the rear end of the dewatering section 2.2.

[0049] Specifically, the main body 1 of the screw press has a mud inlet 1.1 and a mud outlet 1.2 at its two ends. The main body 1 is inclined, and the height of the mud outlet 1.2 is higher than the height of the mud inlet 1.1. This is to allow water to accumulate in the thickening section 2.1 under its own gravity and be dewatered, thereby reducing the water content of the sludge in the dewatering section 2.2.

[0050] The concentrator 2 was further optimized, with the length of the thickening section 2.1 being greater than half the total length of the concentrator 2. This allows for sufficient thickening, ensuring that the sludge moisture content is reduced to a certain level before entering the dewatering section 2.2 for complete dewatering.

[0051] The concentrator 2 was further optimized, with the length of the thickening section 2.1 being less than two-thirds of the total length of the concentrator 2. This allows for a certain dewatering process, enabling the sludge with reduced moisture content to a sufficient level for thorough dewatering.

[0052] The stacked screw body 2 is further optimized. The stacked screw body 2 has a cylindrical cavity inside, and the spiral blade 4 fits into the inner wall of the cavity.

[0053] In the above embodiment, the pitch of the spiral shaft 3 gradually decreases from the thickening section 2.1 to the dewatering section 2.2, and the cross-sectional area of ​​the spiral shaft 3 in the dewatering section 2.2 is larger than that in the thickening section 2.1. The rotation of the spiral shaft 3 pushes the sludge from the thickening section 2.1 to the dewatering section 2.2, generating extremely high internal pressure. Macroscopically, the volume continuously decreases, achieving the purpose of thorough dewatering. The eccentric shaft and the spiral blades 4 with the pitch gradually decreasing along the sludge conveying direction cooperate to form a spiral channel. The instantaneous flow rate of the spiral channel alternates between increasing and decreasing along the sludge conveying direction. The internal pressure generated by the sludge through the spiral channel also alternates between increasing and decreasing. The internal pressure difference improves the problem of local sludge blockage in the dewatering section 2.2 and prevents local shaft blockage in the dewatering section 2.2 after the sludge moisture content decreases.

[0054] The specific embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the specific scope of implementation of this utility model. All equivalent changes made to the shape and structure of this utility model should be included within the protection scope of this utility model.

Claims

1. A dewatering device for a stacked screw press, comprising a stacked screw press body, characterized in that, The main body of the stacked screw includes a stacked screw body formed by alternating fixed rings and moving rings, and a spiral shaft penetrating the stacked screw body. The spiral shaft is provided with spiral blades with a pitch that gradually decreases along the sludge conveying direction. The stacked screw body is divided into a thickening section and a dewatering section in sequence along the sludge conveying direction. The spiral shaft located in the dewatering section is an eccentric shaft, and the cross-sectional area of ​​the spiral shaft located in the dewatering section is larger than the cross-sectional area of ​​the spiral shaft located in the thickening section.

2. The dewatering device for a screw press according to claim 1, characterized in that, The eccentric shaft located in the dewatering section is divided into a first eccentric shaft and a second eccentric shaft along the sludge conveying direction. The first eccentric shaft and the second eccentric shaft are coaxially arranged, and the cross-sectional area of ​​the second eccentric shaft is larger than that of the first eccentric shaft.

3. The dewatering device for a stacked screw press according to claim 2, characterized in that, The eccentric direction of the first eccentric shaft is opposite to that of the second eccentric shaft, the eccentricity of the second eccentric shaft is greater than that of the first eccentric shaft, and the radius of the second eccentric shaft is greater than that of the first eccentric shaft.

4. A dewatering device using a screw press according to claim 1, 2, or 3, characterized in that, The main body of the stacked screw is provided with a mud inlet hole and a mud outlet hole at both ends. The main body of the stacked screw is inclined, and the height of the mud outlet hole is higher than the height of the mud inlet hole.

5. The dewatering device for a stacked screw press according to claim 4, characterized in that, The main body of the stacked screw is provided with a pressure plate on the outside of the mud outlet hole and a pressing mechanism that drives the pressure plate to press against the outside of the mud outlet hole, and the pressure plate covers the mud outlet hole.

6. The dewatering device for a stacked screw press according to claim 5, characterized in that, The clamping mechanism includes an elastic element fixed on the main body of the stacked screw, and the elastic element drives the pressure plate to press against the outside of the mud outlet hole.

7. The dewatering device for a stacked screw press according to claim 6, characterized in that, The number of elastic elements is multiple, and the multiple elastic elements are evenly distributed in a circle according to the central axis of the spiral shaft.

8. A dewatering device using a screw press according to claim 1, 2, or 3, characterized in that, The length of the condensation section is greater than one-half of the total length of the stacked spiral body.

9. The dewatering device for a stacked screw press according to claim 8, characterized in that, The length of the concentration section is less than two-thirds of the total length of the stacked spiral body.

10. A dewatering device using a screw press according to claim 1, 2, or 3, characterized in that, The stacked screw body has a cylindrical cavity, and the helical blades are fitted with the inner wall of the cavity.

Images