A high coagulation performance sludge treatment screen filter type sludge and water separation apparatus and method

Abstract

The present application relates to a kind of high condensation performance sludge treatment screen filter type sludge-water separation equipment and method, including reaction pool, the reaction pool has mud inlet pipe, mud outlet pipe and drain pipe, wherein, the inside of reaction pool is provided with annular surrounding screen, to separate reaction pool into clear water area and sludge area, mud inlet pipe, mud outlet pipe is connected to sludge area, drain pipe is connected to clear water area, sludge area is provided with stirring member, for forming annular flow in sludge area.The equipment is by setting annular screen, and form annular low-speed flow water flow on the inside of screen, the low-speed water flow makes high polymerization sludge group along water flow tangent direction through screen hole, flow direction is perpendicular to screen hole direction, and no larger impact force is generated, avoid sludge floc breakage, reaches the sludge-water separation efficiency far higher than secondary sedimentation tank method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sludge treatment, and particularly relates to a high-agglomeration-performance sludge treatment screen-filtering type sludge-water separation device and method. BACKGROUND

[0002] In a sewage biological treatment process, biological sludge needs to be finally separated from sewage. The most traditional separation method is a secondary sedimentation tank. The sludge can be precipitated in the sedimentation tank due to the feature that the sludge has a higher density than water, so that the separation of sewage and sludge is realized.

[0003] The traditional secondary sedimentation tank has a low hydraulic load, and can only be used at 0.6-1.5 m 3 / (m 2 ·h) [the value of the Outdoor Drainage Design Standard], and a higher hydraulic load is easy to cause sludge running, resulting in turbid effluent. Since the traditional sedimentation tank can only be used at a low hydraulic load, a large-scale municipal sewage plant generally needs to be provided with a sedimentation tank with a large land area. If the maintenance of the sedimentation tank is slightly improper, sludge running will cause a serious decrease in effluent quality. For a sewage plant with a depth treatment, the load of the subsequent depth treatment is increased, which brings inconvenience to operation. SUMMARY

[0004] The present application aims to provide a sludge-water separation structure that can replace the traditional secondary sedimentation tank, i.e., a high-agglomeration-performance sludge treatment screen-filtering type sludge-water separation device and method.

[0005] The present application realizes the above-mentioned purpose through the following technical scheme:

[0006] A high-agglomeration-performance sludge treatment screen-filtering type sludge-water separation device comprises a reaction tank, the reaction tank has a sludge inlet pipe, a sludge discharge pipe and a water discharge pipe, wherein the inside of the reaction tank is provided with an annularly surrounding screen, so as to separate the reaction tank into a clear water zone and a sludge zone, the sludge inlet pipe and the sludge discharge pipe are communicated with the sludge zone, the water discharge pipe is communicated with the clear water zone, and a stirring member is arranged in the sludge zone, the stirring member is a stirring rod or a stirring blade, and is used to form an annular water flow in the sludge zone.

[0007] As a further optimization scheme of the present application, the screen has a group, and the stirring member is arranged at a position close to the inner side of the screen, the inner side of the screen is the sludge zone, and the outer side is the clear water zone. In this scheme, a single screen is used, and the sludge is screened out, so that the land area can be effectively reduced, and the scheme is suitable for occasions with a small-scale flow.

[0008] As a further optimization scheme of the present application, the screen has several groups and is coaxially arranged, and the annular gaps between the screens alternately form sludge zones and clear water zones, wherein the sludge inlet pipe and the sludge outlet pipe are each provided with a branch pipe connected to each sludge zone, and the water outlet pipe is provided with a branch pipe connected to each clear water zone. This scheme forms alternating sludge zones and clear water zones through multiple screens, which can further improve the effective filtration area, increase the treatment capacity, and is suitable for occasions with large flow. When multiple rings are used, each ring should be arranged as a detachable assembly for easy maintenance, and the ring and the bottom plate are connected by means of threads, buckles or other connection methods to fix the position of the ring on the pool bottom.

[0009] As a further optimization scheme of the present application, the flow velocity v of the annular water flow in the sludge zone ranges from 0.15 to 0.50 m / s, and the water level of the sludge zone is higher than that of the clear water zone, and the water level difference is less than v 2 / 2g, g is the acceleration of gravity. Too high flow velocity will increase energy consumption and increase the risk of sludge breakage. Too low flow velocity will affect the treatment capacity of the equipment and increase the risk of blockage. Since the linear velocity of the stirring member is different in the annular area of different radii, in order to control the water flow velocity within the above range, the stirring members in different clear water zones and sludge zones have different widths.

[0010] As a further optimization scheme of the present application, the top view of the reaction tank must be circular or regular polygonal to ensure that the stirring facility can push the water flow to flow in a ring shape by rotation.

[0011] As a further optimization scheme of the present application, the stirring member is driven by a motor and a transmission member, and the stirring member is in a vertical state.

[0012] As a further optimization scheme of the present application, the screen has a mesh number of 280-320 meshes. Too few meshes will cause sludge to leak, and too many meshes will reduce the treatment capacity. The screen is made of corrosion-resistant material.

[0013] As a further optimization scheme of the present application, metal strips are arranged on the surface of the screen to reinforce the screen.

[0014] The present application also provides a method for separating sludge and water by using the above-mentioned screen filter type sludge-water separation equipment, which comprises the following steps:

[0015] S1: A mixture of high coagulation performance sludge and water is introduced into the sludge zone through the sludge inlet pipe, so that the liquid level of the sludge zone is higher than that of the clear water zone. The motor is started to drive the stirring member to stir, so that the flow velocity of the annular water flow in the sludge zone is 0.15-0.50 m / s, and the water is forced to pass through the screen into the clear water zone;

[0016] S2: The sludge deposited in the sludge zone is discharged through the sludge outlet pipe, and the liquid level of the clear water zone is lowered by opening the water outlet pipe, so that the liquid level of the clear water zone is always lower than that of the sludge zone;

[0017] S3: cleaning the inner wall of the screen, the cleaning method including one or more of the following methods: installing a brush on the stirring member; increasing the rotation speed of the water flow in the sludge zone to flush the screen; backwashing the screen from the outside to the inside by a medium-pressure water flushing device.

[0018] The present application has the following beneficial effects:

[0019] The present application sets a ring-shaped screen, and forms a ring-shaped low-speed water flow on the inner side of the screen. The low-speed water flow makes the high-polymer sludge group pass through the screen hole in the tangential direction of the water flow, and the flow direction is perpendicular to the direction of the screen hole, so that a large impact force is not generated, which helps to reduce the breaking of the sludge group, and the filtering efficiency is much higher than that of the secondary sedimentation tank method. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of embodiment 1 of the present application;

[0021] Figure 2 is a schematic diagram of embodiment 2 of the present application;

[0022] In the figure: 1, reaction tank; 11, sludge discharge pipe; 12, sludge inlet pipe; 13, water discharge pipe; 21, screen; 22, metal grid; 23, clean water zone; 24, sludge zone; 31, motor; 32, transmission member; 33, stirring member. DETAILED DESCRIPTION

[0023] It is necessary to point out here that the following detailed description is only used to further illustrate the present application, and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0024] Embodiment 1

[0025] A screen filtration type sludge-water separation device for high-coagulation performance sludge treatment, comprising a reaction tank 1, the reaction tank 1 having a sludge inlet pipe 12, a sludge discharge pipe 11 and a water discharge pipe 13, wherein the reaction tank 1 is internally provided with a ring-shaped screen 21 for separating the reaction tank 1 into a clean water zone 23 and a sludge zone 24, the sludge inlet pipe 12 and the sludge discharge pipe 11 are communicated with the sludge zone 24, the water discharge pipe 13 is communicated with the clean water zone 23, and the sludge zone 24 is provided with a stirring member 33, which is a stirring rod or a stirring blade, for forming a ring-shaped water flow in the sludge zone 24.

[0026] The screen 21 has a group, and the stirring member 33 is arranged at a position close to the inner side of the screen 21, the inner side of the screen 21 being the sludge zone 24, and the outer side being the clean water zone 23.

[0027] The speed of the annular water flow in the sludge area 24 is 0.30 m / s, and the water level of the sludge area 24 is higher than that of the clear water area 23, and the water level difference is less than v 2 The top view of the reaction tank 1 is circular or regular polygonal, the stirring member 33 is driven by the motor 31 and the transmission member 32, the mesh number of the screen 21 is 300 meshes, and the screen 21 is fixed by the metal grid 22.

[0028] The application further provides a method for separating sludge and water by using the screen filter type sludge and water separation device.

[0029] S1: the mixture of sludge with high agglomeration performance and water is introduced into the sludge area 24 through the sludge inlet pipe 12, the liquid level of the sludge area 24 is higher than that of the clear water area 23, the motor 31 is started to drive the stirring member 33 to stir, the flow speed of the annular water flow in the sludge area 24 is 0.15 m / s, and the water is caused to pass through the screen 21 and enter the clear water area 23.

[0030] S2: the sludge deposited in the sludge area 24 is discharged through the sludge discharge pipe 11, and the liquid level of the clear water area 23 is lowered by opening the water discharge pipe 13, so that the liquid level of the clear water area 23 is always lower than that of the sludge area 24.

[0031] S3: the inner wall of the screen 21 is cleaned, and the cleaning mode includes one or more of the following modes: a brush is added to the stirring member 33; the rotation speed of the water flow in the sludge area 24 is increased to flush the screen 21; and the screen 21 is back-flushed from the outside to the inside by a medium-pressure water flushing device.

[0032] The operation principle is as follows: the biological sludge has large particles (the particle size is generally 0.2-0.5 mm, and the particle size of broken sludge is also greater than 0.05-0.1 mm), the Brownian motion is weak, under the condition of maintaining a certain flow speed, the sludge motion trajectory at the edge of the stirrer is forward motion along the tangent direction of the water flow, and under the condition that the pressure difference on both sides of the screen is small, the sludge cannot pass through the screen hole with a diameter smaller than the sludge diameter and a vertical angle with the water flow direction. The water molecules are small, the molecular diffusion speed is fast from the microscopic point of view, although there is motion along the tangent direction of the stirrer, but the water molecules can still easily pass through the 280-320 mesh screen, the penetration speed is fast, the resistance is small, and the penetration flow is large.

[0033] Example 2

[0034] Different from example 1, in this embodiment, the screen 21 has several groups and is concentrically arranged, the annular gaps between the screen 21 alternately form the sludge area 24 and the clear water area 23, the outermost circle is the clear water area 23, wherein the sludge inlet pipe 12 and the sludge outlet pipe 11 are provided with branch pipes connected to each sludge area 24, and the water outlet pipe 13 is provided with branch pipes connected to each clear water area 23, the flow velocity of each sludge area 24 is 0.30 m / s, wherein the flow velocity difference of the sludge area 24 with different radii is gradually reduced by using the same driving motor 31 and gradually reducing the size of the stirring part 33 from the inside to the outside, or using different driving motors 31 for separate driving.

[0035] It should be noted that, due to the structure of the reaction tank 1 and the water permeability of the screen 21, the diameter of the reaction tank 1 should not be greater than 6 m.

[0036] In this embodiment, the maximum diameter of the reactor is 5.25 m, the net distance of the two layers is 0.25 m, and the diameter of the screen 21 in the center is 1 m. The inside is used as the clear water area 23, and then the clear water area 23, the sludge area 24, the clear water area 23, …, the clear water area 23 are arranged in sequence from the inside to the outside.

[0037] Comparative example 1:

[0038] The mud-water separation is carried out by using the secondary sedimentation tank method, wherein the total land area of the secondary sedimentation tank is 113 m 3 , the effective diameter is 10 m, the effective treatment area is 78.5 m 2 , the tank depth is 3 m, and the hydraulic load of the secondary sedimentation tank is measured.

[0039] Comparative example 2:

[0040] The mud-water separation is carried out by using the secondary sedimentation tank method, wherein the total land area of the secondary sedimentation tank is 1384 m 2 , the effective diameter is 40 m, the effective treatment area is 1256 m 2 , the tank depth is 3 m, and the hydraulic load of the secondary sedimentation tank is measured.

[0041] The reaction tank 1 of examples 1-2 and the secondary sedimentation tank of comparative examples 1-2 are calculated, and the effective filtration area of the screen 21 is the total area of the screen 21 after being unfolded.

[0042] During the experiment, first, the reaction tank 1 of examples 1-2 is calculated to make the effluent water quality meet the industry standard, and the total hydraulic load of examples 1-2 is obtained, then based on the hydraulic load, the area of the secondary sedimentation tank that can complete the hydraulic load according to the conventional treatment capacity of the secondary sedimentation tank method is calculated, and the secondary sedimentation tank based on the area is verified, and finally the experimental results are as follows:

[0043]

[0044] Regarding experimental data:

[0045] 1. In the simulation and calculation process, the hydraulic load of the screen 21 per unit area can be stabilized to 10-15 m 3 / (m 2 ·h) during the continuous operation of Example 1 and Example 2. However, considering the existence of a certain degree of blockage during continuous long-time operation and the time wasted for flushing operation, the hydraulic load of the screen 21 per unit area of Example 1 and Example 2 can be at least 5.4 m 3 / (m 2 ·h) after comprehensive calculation, which is lower than the value obtained during continuous operation in the actual test;

[0046] 2. Comparative Example 1 and Comparative Example 2 are both secondary sedimentation tank methods in the prior art. As the common knowledge in the field, the hydraulic load standard per unit area of the secondary sedimentation tank method is generally 0.6-1.5 m 3 / (m 2 ·h), and the data used in this simulation comparison is 1.0 m 3 / (m 2 ·h).

[0047] 3. The effluent water quality of the device meets the requirements of the industry for such sewage separation, and in the experiment, the water quality of the water discharged after filtration by the screen 21 is obviously better than that of the water discharged by the secondary sedimentation tank method relying only on natural sedimentation. As for the suspended matter concentration of the effluent water, there is sludge bulking, sludge floating, and a small amount of sludge loss with water during the operation of the secondary sedimentation tank method, which may cause the suspended matter concentration of the effluent water to be relatively high. Therefore, the effluent water quality after treatment by the reaction tank is better than the treatment effect of the secondary sedimentation tank.

[0048] Conclusion:

[0049] As can be seen from the above table, in the case of smaller flow, the land area of Example 1 is only 2.8% of that of Comparative Example 1 when the total treatment capacity is close, and the water quality after filtration by the multi-layer screen 21 is better than that of the secondary sedimentation tank method;

[0050] In the case of larger flow, the land area of Example 2 is only 1.56% of that of Comparative Example 2, and the separation and treatment capacity of biological sludge and water is twice that of Comparative Example 2. Therefore, it can be concluded that the filtration type sludge and water separation using the annular screen 21 can greatly reduce the land area and has better treatment efficiency for sludge with high coagulation performance.

[0051] It should be noted that the technical scheme of the present application has good treatment effect on sludge with high condensation performance, such as activated sludge, biofilm sludge, or chemical flocculation sludge and water separation, and is not applicable to the separation of sludge and sewage such as highly dispersed and fine particle suspended slurry, turbid natural water, and anaerobic sludge.

[0052] The above-described embodiments only express several embodiments of the present application, which are described in detail and specifically, but should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which are within the protection scope of the present application.

Claims

1. A method of separating slurry in a screen bowl centrifuge, characterized by: The mud-water separation device comprises a reaction tank (1) having a mud inlet pipe (12), a mud outlet pipe (11) and a water outlet pipe (13), wherein the inside of the reaction tank (1) is provided with a ring-shaped surrounding screen (21) for separating the reaction tank (1) into a clean water area (23) and a sludge area (24), the mud inlet pipe (12) and the mud outlet pipe (11) are communicated with the sludge area (24), the water outlet pipe (13) is communicated with the clean water area (23), a stirring member (33) is arranged in the sludge area (24), the stirring member (33) is a stirring rod or a stirring blade for forming a ring-shaped water flow in the sludge area (24); The method comprises the following steps: S1: passing a mixture of high-coagulation-performance sludge and water into the sludge area (24) through the mud inlet pipe (12) to make the liquid level of the sludge area (24) higher than that of the clean water area (23), starting the motor (31) to drive the stirring member (33) to stir, making the outermost flow speed in the sludge area (24) 0.15-0.50 m / s, and forming a ring-shaped low-speed water flow on the inside of the screen (21) to promote water to pass through the screen (21) into the clean water area (23); S2: opening the mud outlet pipe (11) to discharge the sludge deposited in the sludge area (24), and simultaneously opening the water outlet pipe (13) to lower the liquid level of the clean water area (23) so that the liquid level of the clean water area (23) is always lower than that of the sludge area (24); S3: cleaning the inner wall of the screen (21) by one or more of the following cleaning methods: adding a brush on the stirring member (33); increasing the rotation speed of the water flow in the sludge area (24) to flush the screen (21); and performing backwashing on the screen (21) from the outside to the inside by a medium-pressure water flushing device.

2. The method of separating slurry water by the screen type slurry water separating apparatus according to claim 1, characterized in that: The screen (21) has one group, and the stirring member (33) is arranged at a position close to the inside of the screen (21), the inside of the screen (21) is the sludge area (24), and the outside of the screen (21) is the clean water area (23).

3. The method of separating slurry water by the screen type slurry water separating apparatus according to claim 1, characterized in that: The screen (21) has a plurality of groups and is concentrically arranged, and the ring-shaped gaps between the screens (21) alternately form the sludge area (24) and the clean water area (23), wherein the mud inlet pipe (12) and the mud outlet pipe (11) are each provided with a branch pipe communicated with each sludge area (24), and the water outlet pipe (13) is provided with a branch pipe communicated with each clean water area (23).

4. The method of separating slurry water by the screen type slurry water separating apparatus according to claim 1, characterized in that: The annular water flow velocity of the sludge zone (24) v is 0.15-0.50 m / s, and the water level of the sludge zone (24) is higher than that of the clear water zone (23), and the water level difference is less than v 2 / 2g, g is the acceleration of gravity.

5. The method of separating slurry water according to any one of claims 1 to 4, wherein: The top view of the reaction tank (1) is circular or regular polygonal.

6. The method of separating slurry water according to any one of claims 1 to 4, wherein: The stirring member (33) is driven by the motor (31) and a transmission member (32).

7. The method of separating slurry water according to any one of claims 1 to 4, wherein: The screen (21) has a mesh number of 280-320.

8. The method of separating slurry water according to any one of claims 1 to 4, wherein: A metal grid (22) is arranged on the surface of the screen (21) to reinforce the screen (21).

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