AU2017100605A4 - Sludge dehydration device and dehydration method - Google Patents

Abstract

Disclosed is a sludge dehydration device, including a mud storage container (1), a three-dimensional dehydration assembly (20) installed in the mud storage container 5 (1), a pressurization plate (8) disposed above the three-dimensional dehydration assembly (20) and movable up and down, and a driving assembly (5) configured to drive the pressurization plate (8) to move up and down and provide pressure to the pressurization plate (8). The three-dimensional dehydration assembly (20) includes a lower porous plate (2) located at a lower part of the mud storage container (1), an 10 upper porous plate (3) disposed above the lower porous plate (2) and detachably connected to the pressurization plate (8), and a plurality of water drainage pieces (4) connected between the lower porous plate (2) and the upper porous plate (3) and extending along a vertical direction. It is set that at least one side wall of the mud storage container (1) can be opened and closed. In this way, the three-dimensional 15 dehydration assembly (20) is disposed into the lower porous plate (2) and the upper porous plate (3) which correspond to each other, and the plurality of water drainage pieces (4) is connected between the lower porous plate (2) and the upper porous plate (3), thereby increasing water drainage channels for sludge; and the pressurization plate (8) is pressurized by the driving assembly (5), thereby achieving deep 20 dehydration of sludge. Also disclosed is a sludge dehydration method. ..5 .2 ... 54 53

Description

1 2017100605 24 May 2017 SLUDGE DEHYDRATION DEVICE AND DEHYDRATION METHOD BACKGROUND OF THE INVENTION Field of the Invention

The present invention belongs to the field of sludge dehydration, and relates to a 5 dehydration device, and more particularly, to a sludge dehydration device and dehydration method.

Description of Related Art

Currently, there are two increasingly severe problems among water environment problems in China: (1) a large amount of sewage sludge is processed in 10 newly-constructed or already-constructed sewage treatment plants, and a large amount of sewage sludge is generated; and (2) desilting of sediments is conducted for many polluted rivers and lakes, and a large amount of dredging sludge is generated. A common feature of sewage sludge or dredging slduge is high moisture content. How to effectively implement reduction by dehydration has become an important technical 15 requirement in water environment treatment in China. As reported in related researches, it is expected that an annual output of municipal sludge (having a moisture content of 80%) in China will exceed 46 million tons at the end of the 12th five-year plan; and for silt in lakes, an amount of sediments dredged during comprehensive water pollution treatment only in the Dian-Ci Lake already exceeds 10 million m3, 20 and it is expected that an amount of sediments urgently to be desilted due to serious pollution in the Taihu Lake is 30 million m3. The sludge and sediment contaminants occupy a large area during the treatment process. For example, silt from desilting of the Taihu Lake may occupy approximately 15 thousand mu (piled up at a height of 3 meters). Therefore, to reduce a moisture content in sludges becomes a critical 25 technology of reduction. If a moisture content of sludge from the sewage treatment plants decreases from 80% to 60%, a volume of sludge may be reduced to a half thereof.

Currently, patents related to sludge dewatering in China involve: plate press dehydration, vacuum dehydration, centrifugal dehydration, and the like. For example, 2 in an application No. 99803744.3, titled “SILT DEHYDRATION METHOD USING PLATE FILTERS (FILTER PRESSES)”, a flocculant is used to improve the dehydration efficiency, and in a patent No. 200710096620.X, titled “FILTER CLOTH BELT FOR SILT DEHYDRATION AND SILT DEHYDRATION APPARATUS USING SAME”, the sludge dehydration apparatus is similar to a belt press device in a sludge dehydration process. Patents related to secondary dehydration of dehydrated sludge mainly focus on drying treatment, solidification treatment, landfill treatment, and the like. As for secondary dehydration, there is only one patent No. 201010201719.3, titled “SECONDARY DEEP DEHYDRATION METHOD FOR DEHYDRATED SLUDGE”. However, the patent involves two aspects: conditioning and dehydration, and a chemical raw material, a flocculant, and the like are used therein. With the method or the apparatus described above, although sludge can be dehydrated to some extent, the costs are relatively high, or the apparatus is complex or an overall dehydration effect is relatively poor.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a sludge dehydration device to overcome the defects of the prior art.

To achieve the foregoing objective, a technical solution used in the present invention is a sludge dehydration device, including a mud storage container having a mud inlet and a water drainage outlet, a three-dimensional dehydration assembly installed in the mud storage container, a pressurization plate disposed above the three-dimensional dehydration assembly and movable up and down, and a driving assembly configured to drive the pressurization plate to move up and down and provide pressure to the pressurization plate, where the three-dimensional dehydration assembly includes a lower porous plate located at a lower part of the mud storage container, an upper porous plate disposed above the lower porous plate and detachably connected to the pressurization plate, and a plurality of water drainage pieces connected between the lower porous plate and the upper porous plate and extending along a vertical direction, and it is set that at least one side wall of the mud storage container can be opened and closed.

Preferably, the upper porous plate and the lower porous plate both are horizontally disposed, upper and lower ends of the water drainage pieces are 3 respectively connected to the upper porous plate and the lower porous plate, a distance between every two adjacent ones of the water drainage pieces is 15 to 30 cm, and the water drainage pieces are plate-shaped, belt-shaped, or hollow pipe-shaped filter cloths.

Preferably, the upper porous plate and the pressurization plate are connected by using hooks and loops that are engaged with each other, and can be disconnected from each other under a certain pulling force.

Further, snap-in loops are disposed on the upper porous plate, snap-in hooks are disposed on the pressurization plate, the snap-in loops and the snap-in hooks cooperate with each other to connect the three-dimensional dehydration assembly and the pressurization plate, and after dehydration is completed, the pressurization plate is raised to disconnect the snap-in loops from the snap-in hooks.

Preferably, the driving assembly includes a hydraulic cylinder located above the mud storage container and a hydraulic controller connected to the hydraulic cylinder. Further, the dehydration device includes an electromagnetic coil disposed in the pressurization plate and a coil controller connected to the electromagnetic coil. After the electromagnetic coil is energized, the pressurization plate may be connected to a piston rod of the hydraulic cylinder.

Preferably, the mud inlet and the water drainage outlet are located on a side wall of the mud storage container, and a slider is disposed in the mud storage container below the lower porous plate to push the three-dimensional dehydration assembly and the mud out of the mud storage container after dehydration.

Preferably, a water conducting pipe connected to the water drainage outlet is disposed in the side wall of the mud storage container.

Another objective of the present invention is to provide a sludge dehydration method for use with the sludge dehydration device, the method including the following steps: (a) installing a three-dimensional dehydration assembly in a mud storage container; (b) driving, by a driving assembly, a pressurization plate to move down, enabling the pressurization plate to connect to an upper porous plate, and then move up to drive 4 the upper porous plate to move up until water drainage pieces are straight; (c) injecting sludge into the mud storage container through a mud inlet until a space between the upper porous plate and a lower porous plate is filled with sludge, where the sludge having a moisture content of 70 to 85 wt% from sewage plants, silt having a moisture content of 45 to 65 wt% from desilting of rivers and lakes, or a combination of the two; (d) starting the driving assembly for stage-by-stage pressurization with dwelling at each stage of pressure; (e) raising the pressurization plate to be disconnected from the three-dimensional dehydration assembly; (f) opening at least one side wall of the mud storage container, to expel a mixture of the three-dimensional dehydration assembly and the mud; and (g) breaking mud lumps in the mixture to recycle the three-dimensional dehydration assembly for reuse after washing.

Preferably, the stage-by-stage consolidation pressure is: maintaining for 0.5 to 2 hours at the first stage of pressure of 80 to 150 kPa; maintaining for 0.5 to 2 hours at the second stage of pressure of 180 to 250 kPa; maintaining for 1 to 3 hours at the third stage of pressure of 350 to 500 kPa; maintaining for 2 to 5 hours at the fourth stage of pressure of 550 to 750 kPa; and maintaining for 2 to 5 hours at the fifth stage of pressure of 800 to 900 kPa.

With the technical solutions above, the present invention has the following advantages compared with the prior art: in the sludge dehydration device of the present invention, a three-dimensional dehydration assembly is disposed into a lower porous plate and an upper porous plate which correspond to each other, and a plurality of water drainage pieces is connected between the lower porous plate and the upper porous plate, thereby increasing water drainage channels for sludge; and a pressurization plate is pressurized by a driving assembly, thereby achieving deep dehydration of sludge. The device has a simple structure, and no auxiliary material for dehydration is added; therefore, the costs are low. 5

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural diagram of a sludge dehydration device according to the present invention; FIG. 2 is a schematic structural diagram of a three-dimensional dehydration assembly of the sludge dehydration device according to the present invention; and FIG. 3 is a top view of FIG. 1. 1. Mud storage container; 11: Water drainage outlet; 12: Mud inlet; 13: Side wall; 20: Three-dimensional dehydration assembly; 2: Lower porous plate; 3: Upper porous plate; 31: Snap-in loop; 4: Water drainage piece; 5: Driving assembly; 51: Coil controller; 52: Hydraulic cylinder; 53: Hydraulic controller; 54: Electromagnetic coil; 6: Water conducting pipe; 7: Slider; 8: Pressurization plate.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 to FIG. 3, a sludge dehydration device mainly includes a mud storage container 1, a three-dimensional dehydration assembly 20, a pressurization plate 8, and a driving assembly 5. The three-dimensional dehydration assembly 20 is installed in the mud storage container 1. The pressurization plate 8 is disposed above the three-dimensional dehydration assembly 20 and is movable up and down. The driving assembly 5 is connected to the pressurization plate 8, and is configured to drive the pressurization plate 8 to move up and down and provide pressure to the pressurization plate 8.

The three-dimensional dehydration assembly 20 includes a lower porous plate 2, an upper porous plate 3, and water drainage pieces 4. The lower porous plate 2 is located at a lower part of the mud storage container 1, and is horizontally disposed to be parallel with the lower part of the mud storage container 1. The upper porous plate 3 is disposed above and corresponds to the lower porous plate 2, and is detachably connected to the pressurization plate 8. There are several modes of detachable connection. In this embodiment, snap-in loops 31 are disposed on the upper porous plate 3, snap-in hooks are disposed on the pressurization plate 8, and the snap-in 6 hooks and the snap-in loops 31 cooperate with each other to connect the three-dimensional dehydration assembly 20 and the pressurization plate 8. When the pressurization plate 8 is driven by the driving assembly 5 to move up and down, the upper porous plate 3 may move in synchronization with the pressurization plate. After dehydration is completed, the pressurization plate 8 is raised to disconnect the snap-in hooks from the snap-in loops 31. There are a plurality of water drainage pieces 4, the water drainage pieces extend along a vertical direction, upper and lower ends of the water drainage pieces are respectively connected to the upper porous plate 3 and the lower porous plate 2, and a distance between every two adjacent ones of the water drainage pieces 4 is preferably 15 to 30 cm. There may be several forms of the water drainage pieces 4, for example, which may be plate-shaped, belt-shaped, or hollow pipe-shaped, provided that the water drainage pieces are flexible (for example, water drainage filter cloths) because deformation of the water drainage pieces may occur under the action of the pressurization plate 8.

The mud storage container 1 is of a common regular shape, for example, a rectangular, square, or cylindrical shape. In this embodiment, the mud storage container is of a rectangular shape, with an effective volume of 6 m3 (length x width x height = 2mxlmx3m).A water drainage outlet 11 and a mud inlet 12 are disposed on a side wall of the mud storage container. The position of the water drainage outlet 11 corresponds to the position of the lower porous plate 2, and a distance between the mud inlet 12 and the lower porous plate 2 is less than a maximum distance between the upper porous plate 3 and the lower porous plate 2. In this way, the three-dimensional dehydration assembly 20 is disposed into the lower porous plate 2 and the upper porous plate 3 which correspond to each other, and the plurality of water drainage pieces 4 is connected between the lower porous plate and the upper porous plate, thereby increasing water drainage channels for sludge; and the driving assembly 5 is used for further pressurization, thereby achieving deep dehydration. The device has a simple structure, and no auxiliary material for dehydration is added; therefore, the costs are low.

In this embodiment, the three-dimensional dehydration assembly 20 is detachably installed in the mud storage container 1, and it is set that at least one side wall 13 of the mud storage container 1 can be opened and closed. In this way, the three-dimensional dehydration assembly 20 can be placed into or taken out of the mud 7 storage container 1 through the side door 13. Therefore, one mud storage container 1 may be provided with a plurality of three-dimensional dehydration assemblies 20, thereby increasing use efficiency of the mud storage container 1 and increasing dehydration efficiency of sludge. A plurality of snap-in loops 31 connected to the pressurization plate 8 are disposed at the top of the upper porous plate 3, and a slider 7 is disposed at the bottom of the lower porous plate 2. In this way, after sludge is dehydrated, the driving assembly 5 is raised to disconnect the pressurization plate 8 from the upper porous plate 3, the side door 13 is opened, and the three-dimensional dehydration assembly 20 mixed with mud lumps may be pushed out of the mud storage container 1 by using the slider 7. A water conducting pipe 6 communicating with the water drainage outlet 11 is disposed in the side wall of the mud storage container 1, and an upper end of the water conducting pipe 6 may correspond to the upper porous plate 3, so that water conducting efficiency can be improved, resulting in time savings.

In this embodiment, the driving assembly 5 includes a hydraulic cylinder 52 connected to the pressurization plate 8 and located above the mud storage container 1, and a hydraulic controller 53 connected to the hydraulic cylinder 52, to accurately control pressurization on the upper porous plate 3. The sludge dehydration device further includes an electromagnetic coil 54 disposed in the pressurization plate 8 and a coil controller 51 connected to the electromagnetic coil 54, to improve the degree of automation of the device. When energized, the electromagnetic coil 54 generates a magnetic force to connect the pressurization plate 8 and the hydraulic cylinder 52; and when the electromagnetic coil 54 is not energized, the acting force between the pressurization plate 8 and the hydraulic cylinder 52 is removed so that the pressurization plate and the hydraulic cylinder may be disconnected from each other.

For the sludge dehydration device above, the present invention further relates to a sludge dehydration method, including the following steps: (a) sequentially assembling an upper porous plate 3, a plurality of water drainage pieces 4 (a distance between every two water drainage pieces 4 is approximately 15 cm), and a lower porous plate 2 into a three-dimensional dehydration assembly 20, and installing the three-dimensional dehydration assembly 20 in a mud storage container 1; (b) lowering a driving assembly 5 to drive a pressurization plate 8 to move down, so that the pressurization plate 8 is connected to the upper porous plate 3; then, raising the 8 pressurization plate 8 to drive the upper porous plate 3 to move up until the water drainage pieces 4 are straight; (c) injecting sludge into the mud storage container 1 (there are several modes of injection, for example, pumping by a plunger pump or direct feeding by a conveyer belt) through a mud inlet 12, until a space between the upper porous plate 3 and the lower porous plate 2 is filled with sludge (the sludge includes sludge having a moisture content of 70 to 85 wt% from sewage plants, silt having a moisture content of 45 to 65 wt% from desilting of rivers and lakes, or a combination of the two), and closing the mud inlet 12; (d) starting the driving assembly 5 for stage-by-stage pressurization with dwelling at each stage of pressure, specifically including: maintaining for 0.5 to 2 hours at the first stage of pressure of 80 to 150 kpa; raising the pressure to the second stage of pressure of 180 to 250 kpa and maintaining for 0.5 to 2 hours; raising the pressure to the third stage of pressure of 350 to 500 kpa and maintaining for 1 to 3 hours; maintaining for 2 to 5 hours at the fourth stage of pressure of 550 to 750 kpa; finally maintaining the pressure at the fifth stage of pressure of 800 to 900 kpa for 2 to 5 hours; thereby completing deep dehydration; (e) raising the pressurization plate 8 to be disconnected from the three-dimensional dehydration assembly 20; (f) opening a side wall 13 of the mud storage container 1, to push the three-dimensional dehydration assembly 20 mixed with mud lumps out of the mud storage container 1 by using a slider 7; and (g) breaking the mud lumps to recycle the three-dimensional dehydration assembly 20 for reuse after washing. In addition, one mud storage container 1 may be provided with a plurality of three-dimensional dehydration assemblies 20, thereby improving use efficiency of the mud storage container 1 and improving dehydration efficiency of sludge.

The dehydration effect of the sludge dehydration device in the present invention is associated with a distance between sludge and the three-dimensional dehydration assembly 20. The moisture content of sludge close to the water drainage pieces 4 (filter cloths), the lower porous plate 2, and the upper porous plate 3 may decrease to 40% or less through dehydration, and the moisture content of sludge farthest from the filter cloths is less than 65%, and an overall moisture content of sludge is less than 60%. In this embodiment, a space between the filter cloths is set to 15 cm, a maximum load pressure is 800 kpa, an initial moisture content of sludge is 74%, and a pressurization time is 8 h (that is, the first stage of pressure is 100 kpa and maintained 2017100605 24 May 2017 9 for 1 hour; the pressure is raised to 200 kpa and maintained for 1 hour; the pressure is raised to 400 kpa and maintained for 2 hours; the pressure is raised to 600 kpa and maintained for 2 hours; and finally, the pressure is raised to 800 kpa, and maintained for 2 hours). The moisture content of the sludge after being processed by the device is 5 decreased to 55%. From the perspective of geotechnical engineering, difficulty in dehydration is mainly due to a low permeation coefficient of sludge, especially sludge. A solution for the low permeation coefficient may be implemented by adding water drainage channels (the sand-drain theory) as described in the present invention.

The foregoing embodiments are merely used to describe the technical concept 10 and features of the present invention, to enable those skilled in the art to understand and implement the content of the present invention, and are not intended to limit the protection scope of the present invention. Any equivalent change or modification made according to the spirit and essence of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. CLAIMS:

   1. A sludge dehydration device, comprising: a mud storage container having a mud inlet and a water drainage outlet, a three-dimensional dehydration assembly installed in the mud storage container, a pressurization plate disposed above the three-dimensional dehydration assembly and movable up and down, and a driving assembly configured to drive the pressurization plate to move up and down and provide pressure to the pressurization plate, wherein the three-dimensional dehydration assembly comprises a lower porous plate located at a lower part of the mud storage container, an upper porous plate disposed above the lower porous plate and detachably connected to the pressurization plate, and a plurality of water drainage pieces connected between the lower porous plate and the upper porous plate and extending along a vertical direction, and it is set that at least one side wall of the mud storage container can be opened and closed.
2. 2. The sludge dehydration device according to claim 1, wherein the upper porous plate and the lower porous plate both are horizontally disposed, upper and lower ends of the water drainage pieces are respectively connected to the upper porous plate and the lower porous plate, a distance between every two adjacent ones of the water drainage pieces is 15 to 30 cm, and the water drainage pieces are plate-shaped, belt-shaped, or hollow pipe-shaped fdter cloths.
3. 3. The sludge dehydration device according to claim 1, wherein the upper porous plate and the pressurization plate are connected by means of hooks and loops that are engaged with each other, and can be disconnected from each other under a certain pulling force.
4. 4. The sludge dehydration device according to claim 3, wherein snap-in loops are disposed on the upper porous plate, snap-in hooks are disposed on the pressurization plate, the snap-in loops and the snap-in hooks cooperate with each other to connect the three-dimensional dehydration assembly and the pressurization plate, and after dehydration is completed, the pressurization plate is raised to disconnect the snap-in loops from the snap-in hooks.
5. 5. The sludge dehydration device according to claim 1, wherein the driving assembly comprises a hydraulic cylinder located above the mud storage container and a hydraulic controller connected to the hydraulic cylinder.
6. 6. The sludge dehydration device according to claim 5, wherein the dehydration device further comprises an electromagnetic coil disposed in the pressurization plate and a coil controller connected to the electromagnetic coil.
7. 7. The sludge dehydration device according to claim 1, wherein the mud inlet and the water drainage outlet are located on a side wall of the mud storage container, and a slider is disposed in the mud storage container below the lower porous plate to push the three-dimensional dehydration assembly and the mud out of the mud storage container after dehydration.
8. 8. The sludge dehydration device according to claim 1, wherein a water conducting pipe connected to the water drainage outlet is disposed in the side wall of the mud storage container.
9. 9. A sludge dehydration method for use with the sludge dehydration device according to any one of claims 1 to 8, the method comprising the following steps: (a) installing a three-dimensional dehydration assembly in a mud storage container; (b) driving, by a driving assembly, a pressurization plate to move down, enabling the pressurization plate to connect to an upper porous plate, and then move up to drive the upper porous plate to move up until water drainage pieces are straight; (c) injecting sludge into the mud storage container through a mud inlet until a space between the upper porous plate and a lower porous plate is fdled with sludge, wherein the sludge comprises sludge having a moisture content of 70 to 85 wt% from sewage plants, silt having a moisture content of 45 to 65 wt% from desilting of rivers and lakes, or a combination of the two; (d) starting the driving assembly for stage-by-stage pressurization with dwelling at each stage of pressure; (e) raising the pressurization plate to be disconnected from the three-dimensional dehydration assembly; (f) opening at least one side wall of the mud storage container, to expel a mixture of the three-dimensional dehydration assembly and the mud; and (g) breaking mud lumps in the mixture to recycle the three-dimensional dehydration assembly for reuse after washing.
10. 10. The sludge dehydration method according to claim 9, wherein the stage-by-stage pressurization is: maintaining for 0.5 to 2 hours at the first stage of pressure of 80 to 150 kpa; maintaining for 0.5 to 2 hours at the second stage of pressure of 180 to 250 kpa; maintaining for 1 to 3 hours at the third stage of pressure of 350 to 500 kpa; maintaining for 2 to 5 hours at the fourth stage of pressure of 550 to 750 kpa; and maintaining for 2 to 5 hours at the fifth stage of pressure of 800 to 900 kpa.