Sludge concentration device

Abstract

The invention discloses a sludge concentration device, which comprises a concentration tank and at least one blending tank, the blending tank is provided with a stirring device, the blending tank is provided with a sludge adding port and a lime adding port, the sludge adding port is connected with the concentration tank through a sludge adding pipe, and the lime adding port is connected with the concentration tank through a lime adding pipe. The sludge adding pipe is provided with a first sludge pump and a pipeline mixer, the pipeline mixer is also provided with a ferric salt adding port for adding a ferric salt solution, the lime adding port is communicated with a lime adding pipeline, and the bottom of the blending tank is provided with a sludge discharging pipe. A control valve and a second sludge pump are arranged on the sludge discharge pipe, the downstream of the sludge discharge pipe is used for being connected with a plate filter press, and an iron salt solution is introduced into the sludge concentration device, so that microorganisms in the sludge are subjected to modified wall breaking, and the water content of a filter cake is reduced.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a sludge thickening device. Background Technology

[0002] In wastewater treatment processes, after biological treatment, wastewater settles in primary, secondary, and tertiary sedimentation tanks. The settled sludge is discharged into a sludge thickening tank through a sludge discharge pipe. Current sludge thickening methods involve adding quicklime to the thickening tank for conditioning. The added quicklime modifies and dewaters the sludge, and the generated calcium carbonate causes sludge particles to aggregate, improving the sludge's physical structure, accelerating dewatering, and reducing moisture content. The conditioned sludge is then fed into a plate filter press for filtration. However, this sludge thickening method requires the introduction of a large amount of quicklime, thus indirectly increasing the amount of sludge and consequently the amount of the final filter cake. Furthermore, the large amount of quicklime introduced also increases costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a sludge thickening device that introduces an iron salt solution to modify and break down the microorganisms in the sludge, thereby reducing the moisture content of the filter cake. Furthermore, only a small amount of lime needs to be added to adjust the pH, which solves the problem of needing to add a large amount of lime, thereby indirectly increasing the amount of sludge.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is: a sludge thickening device, comprising a thickening tank and at least one mixing tank, wherein the mixing tank is equipped with a stirring device, a sludge adding port and a lime adding port, the sludge adding port being connected to the thickening tank via a sludge adding pipe, the sludge adding pipe being equipped with a first sludge pump and a pipeline mixer, the pipeline mixer being further equipped with an iron salt adding port for adding iron salt solution, the lime adding port being connected to a lime adding pipeline, a sludge discharge pipe being provided at the bottom of the mixing tank, the sludge discharge pipe being equipped with a control valve and a second sludge pump, and the downstream of the sludge discharge pipe being connected to a plate filter press.

[0005] As a preferred embodiment, the sludge addition pipe includes a main sludge addition pipe and multiple branch sludge addition pipes. The pipe mixer and the first sludge pump are installed on the main sludge addition pipe. Each branch sludge addition pipe is connected to a sludge addition port of the mixing tank. Each branch sludge addition pipe is equipped with a control valve.

[0006] As a preferred embodiment, one end of the mixing cylinder is a sludge inlet end, and the other end is a sludge outlet end. The mixing cylinder is provided with a first support perforated plate, a second support perforated plate, a third support perforated plate, and a fourth support perforated plate. A first mixing screw is provided between the first support perforated plate and the second support perforated plate, and a second mixing screw is provided between the third support perforated plate and the fourth support perforated plate. The spiral blades of the first mixing screw and the second mixing screw rotate in the same direction and provide auxiliary force to the sludge towards the sludge outlet end. The iron salt addition port is located between the first support perforated plate and the second support perforated plate.

[0007] As a preferred embodiment, a buffer cavity is provided between the third support plate and the second support plate, and a central shaft is provided between the third support plate and the second support plate, with a rotating plate rotatably mounted on the central shaft.

[0008] As a preferred embodiment, the second and third support orifice plates have the same shape. The second support orifice plate includes a middle plate portion and a plurality of fan-shaped portions disposed on the outer side of the middle plate portion. The fan-shaped portions form a sludge flow channel between them, and the fan-shaped portions are welded to the inner cavity of the mixing cylinder.

[0009] As a preferred embodiment, the rotating orifice plate includes a central cylinder and an outer ring, which are connected by a number of spaced connecting ribs, and the gaps between the connecting ribs form sludge channels; the central cylinder is fitted onto the central shaft and limited on both sides by limiting nuts, and the outer ring is fitted with the inner clearance of the mixing cylinder.

[0010] As a preferred embodiment, the stirring device includes a stirring shaft rotatably mounted on the mixing tank, the stirring shaft being vertically arranged and having a plurality of stirring blades, and a geared motor for driving the stirring shaft to rotate is provided on the top of the mixing tank.

[0011] After adopting the above technical solution, the effect of the present invention is as follows: The sludge thickening device includes a thickening tank and at least one mixing tank. The mixing tank is equipped with a stirring device, a sludge inlet, and a lime inlet. The sludge inlet is connected to the thickening tank via a sludge inlet pipe. The sludge inlet pipe is equipped with a first sludge pump and a pipeline mixer. The pipeline mixer is also equipped with an iron salt inlet for adding iron salt solution. The lime inlet is connected to a lime inlet pipe. A sludge discharge pipe is located at the bottom of the mixing tank. A control valve and a second sludge pump are installed on the sludge discharge pipe. The downstream of the sludge discharge pipe is used to connect to a plate filter press. Therefore, after the sludge is sent to the thickening tank, it is pumped into the mixing tank by the first sludge pump. During the transportation process, an iron salt solution is added. This iron salt solution can be ferric chloride or polyferric sulfate solution. The added iron salt will modify the sludge, especially by breaking down the cell walls of the organisms in the sludge, thus achieving a cell wall breaking effect. This allows for better dewatering. The iron salt neutralizes the surface charge of the sludge particles, reduces colloidal repulsion, promotes flocculation and sedimentation, and reduces the surface area of ​​the flocs, thereby reducing water adsorption. After the addition of iron salt, the sludge becomes acidic. At this time, a small amount of lime is added to the mixing tank to neutralize it, which can reduce the corrosion of the sludge on the transportation pipeline and the mixing tank, thereby extending the service life of the equipment.

[0012] Furthermore, since one end of the mixing cylinder is the sludge inlet and the other end is the sludge outlet, and the mixing cylinder is equipped with a first support perforated plate, a second support perforated plate, a third support perforated plate, and a fourth support perforated plate, a first mixing screw is disposed between the first support perforated plate and the second support perforated plate, and a second mixing screw is disposed between the third support perforated plate and the fourth support perforated plate. The spiral blades of the first mixing screw and the second mixing screw rotate in the same direction and provide an auxiliary force to the sludge towards the sludge outlet. The iron salt addition port is disposed between the first support perforated plate and the second support perforated plate. Therefore, the sludge enters from the sludge inlet and is thoroughly mixed with the iron salt after passing through the first mixing screw and the second mixing screw. At the same time, since the spiral blades of the first mixing screw and the second mixing screw rotate in the same direction and provide an auxiliary force to the sludge towards the sludge outlet, this is better suited for mixing sludge with poor fluidity.

[0013] Furthermore, since a buffer chamber is provided between the third support orifice plate and the second support orifice plate, and a central shaft is provided between the third support orifice plate and the second support orifice plate, a rotating orifice plate is rotatably mounted on the central shaft. Due to the buffer chamber, the sludge will also rotate when it is conveyed by the spiral blades of the first and second mixing screws. When the sludge rotates and enters the buffer chamber, its flow speed will be slowed down. At the same time, as the sludge is conveyed by the spiral, the rotating orifice plate will move accordingly. This moving rotating orifice plate will disrupt the conveying state of the sludge, which facilitates the sludge to be mixed again in the area of ​​the second mixing screw. Therefore, the sludge can be mixed better in this pipeline mixer. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a structural schematic diagram of an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the structure of the pipeline mixer according to an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the structure of the second support perforated plate according to an embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of the structure of the rotating perforated plate according to an embodiment of the present invention;

[0019] In the attached diagram: 1. Thickening tank; 2. Mixing tank; 3. Agitator; 31. Agitator shaft; 32. Agitator blades; 33. Gear motor; 4. Sludge inlet; 5. Lime inlet; 6. Main sludge inlet pipe; 7. Branch sludge inlet pipe; 8. First sludge pump; 9. Pipeline mixer; 91. Mixing cylinder; 92. Buffer chamber; 93. Rotating orifice plate; 931. Central cylinder section; 932. Outer ring section; 933. Connecting rib; 94. First support orifice plate; 941. Intermediate plate section; 942. Fan-shaped section; 943. Sludge flow channel; 95. Second support orifice plate; 96. Third support orifice plate; 97. Fourth support orifice plate; 98. First mixing screw; 99. Second mixing screw; 910. Sludge inlet end; 911. Sludge outlet end; 10. Iron salt inlet; 11. Sludge discharge pipe; 12. Second sludge pump. Detailed Implementation

[0020] The present invention will be further described in detail below through specific embodiments.

[0021] like Figure 1-4As shown, a sludge thickening device includes a thickening tank 1 and at least one mixing tank 2. The mixing tank 2 is equipped with a stirring device 3, a sludge inlet 4, and a lime inlet 5. The sludge inlet 4 is connected to the thickening tank 1 via a sludge inlet pipe. The sludge inlet pipe is equipped with a first sludge pump 8 and a pipeline mixer 9. The pipeline mixer 9 is also equipped with an iron salt inlet 10 for adding iron salt solution. The lime inlet 5 is connected to a lime inlet pipeline. The bottom of the mixing tank 2 is equipped with a sludge discharge pipe 11. The sludge discharge pipe 11 is equipped with a control valve and a second sludge pump 12. The downstream of the sludge discharge pipe 11 is used to connect to a plate filter press.

[0022] In this embodiment, the stirring device 3 includes a stirring shaft 31 rotatably mounted on the mixing tank 2. The stirring shaft 31 is vertically arranged and has several stirring blades 32. A reduction motor 33 for driving the stirring shaft 31 to rotate is provided on the top of the mixing tank 2. The sludge adding pipe includes a main sludge adding pipe 6 and multiple branch sludge adding pipes 7. The pipe mixer 9 and the first sludge pump 8 are arranged on the main sludge adding pipe 6. Each branch sludge adding pipe 7 is connected to a sludge adding port 4 of the mixing tank 2. A control valve is provided on each branch sludge adding pipe 7.

[0023] The pipeline mixer 9 includes a mixing cylinder 91, one end of which is a sludge inlet end 910 and the other end is a sludge outlet end 911. The mixing cylinder 91 is provided with a first support perforated plate 94, a second support perforated plate 95, a third support perforated plate 96 and a fourth support perforated plate 97. A first mixing screw 98 is provided between the first support perforated plate and the second support perforated plate. A second mixing screw 99 is provided between the third support perforated plate 96 and the fourth support perforated plate 97. The spiral blades of the first mixing screw 98 and the second mixing screw 99 rotate in the same direction and provide an auxiliary force to the sludge towards the sludge outlet end 911. The iron salt addition port 10 is provided between the first support perforated plate 94 and the second support perforated plate 95.

[0024] In this embodiment, a buffer cavity 92 is provided between the third support plate 96 and the second support plate 95. A central shaft is provided between the third support plate 96 and the second support plate 95, and a rotating orifice plate 93 is rotatably mounted on the central shaft. The second support plate 95 and the third support plate 96 have the same shape. The second support plate 95 includes a middle plate portion 941 and a plurality of fan-shaped portions 942 disposed outside the middle plate portion 941. The fan-shaped portions 942 form sludge flow channels 943, and the fan-shaped portions 942 are welded to the inner cavity of the mixing cylinder 91. The rotating orifice plate 93 includes a central cylinder portion 931 and an outer ring portion 932. The central cylinder and the outer ring portion 932 are connected by a plurality of spaced connecting ribs 933, and the gaps between the connecting ribs 933 form sludge channels. The central cylinder portion 931 is mounted on the central shaft and limited on both sides by limiting nuts. The outer ring portion 932 is in clearance fit with the inner cavity of the mixing cylinder 91.

[0025] During operation, the sludge is first fed into the thickening tank 1, and then sent to the mixing tank 2 via the first sludge pump 8 and the pipeline mixer 9. During the transportation process, the pipeline mixer 9 is equipped with an iron salt addition port 10 to add iron salt solution. The sludge enters from the sludge inlet end 910 and is thoroughly mixed by the first mixing screw 98 and the second mixing screw 99. The spiral blades of the first mixing screw 98 and the second mixing screw 99 rotate in the same direction and provide an auxiliary force to the sludge towards the sludge outlet end 911. A buffer chamber 92 and a central shaft are provided between the third support orifice plate 96 and the second support orifice plate 95. As the sludge is transported by the spiral blades of the first mixing screw 98 and the second mixing screw 99, the sludge also rotates. When it enters the buffer chamber, the flow speed is slowed down. At the same time, as the sludge is spirally transported, the rotating orifice plate 93 moves accordingly, thereby disrupting the sludge transport state and making the mixing more thorough. During this process, the iron salt solution modifies the sludge, disrupting the cell walls of the organisms within the sludge to achieve a cell-wall breaking effect. The iron salt also neutralizes the surface charge of the sludge particles, promoting flocculation and sedimentation, while simultaneously reducing the surface area of ​​the flocs, decreasing water adsorption, and further concentrating the sludge. However, the addition of iron salts makes the sludge acidic overall. Therefore, lime can be added to the mixing tank 2 for neutralization, and the mixture is further stirred by the stirring device 3. The geared motor 33 drives the stirring shaft 31 and stirring blades 32 to rotate, further mixing the sludge in the mixing tank 2.

[0026] In this embodiment, the iron salt solution can be iron salt, primarily referring to ferric chloride or polyferric sulfate solution. There are three mixing tanks (2). Of course, this can be adjusted according to production needs.

[0027] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications and alterations made to the technical solutions of the present invention without departing from the spirit of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A sludge thickening device, characterized in that: The system includes a thickening tank and at least one mixing tank. The mixing tank is equipped with a stirring device, a sludge inlet, and a lime inlet. The sludge inlet is connected to the thickening tank via a sludge inlet pipe. The sludge inlet pipe is equipped with a first sludge pump and a pipeline mixer. The pipeline mixer is also equipped with an iron salt inlet for adding iron salt solution. The lime inlet is connected to a lime inlet pipe. The bottom of the mixing tank is equipped with a sludge discharge pipe, which is equipped with a control valve and a second sludge pump. The downstream end of the sludge discharge pipe is connected to a plate filter press.

2. The sludge thickening device as described in claim 1, characterized in that: The sludge addition pipe includes a main sludge addition pipe and multiple branch sludge addition pipes. The pipe mixer and the first sludge pump are installed on the main sludge addition pipe. Each branch sludge addition pipe is connected to the sludge addition port of the mixing tank. Each branch sludge addition pipe is equipped with a control valve.

3. The sludge thickening device as described in claim 2, characterized in that: The pipeline mixer includes a mixing cylinder, one end of which is a sludge inlet and the other end is a sludge outlet. The mixing cylinder is equipped with a first support perforated plate, a second support perforated plate, a third support perforated plate, and a fourth support perforated plate. A first mixing screw is positioned between the first and second support perforated plates, and a second mixing screw is positioned between the third and fourth support perforated plates. The spiral blades of the first and second mixing screws rotate in the same direction and provide auxiliary force to the sludge towards the sludge outlet. The iron salt addition port is located between the first and second support perforated plates.

4. The sludge thickening device as described in claim 3, characterized in that: A buffer cavity is provided between the third support plate and the second support plate, and a central shaft is provided between the third support plate and the second support plate. A rotating plate is rotatably mounted on the central shaft.

5. The sludge thickening device as described in claim 4, characterized in that: The second and third support orifice plates have the same shape. The second support orifice plate includes a middle plate and a plurality of fan-shaped portions disposed on the outer side of the middle plate. The fan-shaped portions form a sludge flow channel between them. The fan-shaped portions are welded to the inner cavity of the mixing cylinder.

6. The sludge thickening device as described in claim 5, characterized in that: The rotating orifice plate includes a central cylinder and an outer ring. The central cylinder and the outer ring are connected by several spaced connecting ribs, and the gaps between the connecting ribs form sludge channels. The central cylinder is fitted onto the central shaft and is limited on both sides by limiting nuts. The outer ring is fitted with the inner clearance of the mixing cylinder.

7. The sludge thickening device as described in claim 6, characterized in that: The stirring device includes a stirring shaft rotatably mounted on the mixing tank. The stirring shaft is vertically arranged and has a plurality of stirring blades. A geared motor for driving the stirring shaft to rotate is provided on the top of the mixing tank.

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