Sludge concentration tank, sludge concentration system and application method

Abstract

The invention relates to a sludge concentration tank, a sludge concentration system and an application method.The sludge concentration tank comprises a tank body (1), the interior of the tank body is composed of a gas collecting area (4), a settling area (5) and a sludge storage area (6) from top to bottom, the gas collecting area is provided with a gas outlet (7), the side wall of the settling area is provided with a sludge feeding pipe (8), and the upper portion of the settling area is provided with a liquid discharging pipe (12); a sludge discharge pipe (9) is arranged at the bottom of the sludge storage area; the rotational flow inner part (2) is arranged in the settling area, the rotational flow inner part is a cylinder with the pipe diameter reduced from top to bottom, an opening in the bottom of the rotational flow inner part is a mud outlet, the top of the rotational flow inner part is closed, a clear liquid outlet (16) is formed in the rotational flow inner part, and a feeding opening is formed in the side wall of the rotational flow inner part and communicated with the sludge feeding pipe. The sludge concentration tank and the sludge concentration system can realize efficient separation of sludge and water, and the subsequent sludge treatment energy consumption is reduced; meanwhile, gas is collected, and the deodorization effect is achieved. The working efficiency and the separation efficiency are relatively high.

Description

Technical Field

[0001] This invention relates to the field of solid-liquid separation, and more specifically, to a sludge thickening system and method in the field of environmental protection. Background Technology

[0002] To effectively and economically further treat sludge, it must first be thickened. Sludge thickening is an effective method to reduce the moisture content and volume of sludge, and it is suitable for sludge with high moisture content, such as activated sludge, which has a moisture content as high as about 99%. When the moisture content of sludge is reduced from 99% to 96%, the volume of sludge can be reduced to 1 / 4 of its original size.

[0003] Traditional sludge thickening tanks commonly use gravity thickening methods, primarily to reduce interstitial water in the sludge. A feed pipe runs through the top of the tank, while a sludge discharge pipe is located at the bottom. After the sludge-water mixture enters the tank through the feed pipe, it remains in the tank for 12 to 48 hours. The sludge settles to the bottom of the tank and is discharged through the sludge discharge pipe, while the supernatant is discharged through the water discharge pipe located at the top of the tank.

[0004] CN202754885U discloses a sludge thickening tank, including a tank body, a geared motor, upper and lower stirring blades, a support and sliding bearings, a pump, an overflow port, and a supernatant discharge port. It combines the flocculation and thickening processes, utilizing the sludge's own gravity for compression, resulting in good sedimentation and flocculation effects. However, it requires a stirring device, making operation relatively complex.

[0005] CN215026239U discloses a mud concentration tank, comprising: a storage tank; a mud inlet pipe disposed at the top of the storage tank; a central feed cylinder coaxially disposed with the storage tank and located inside the storage tank, the upper end face of the central feed cylinder being flush with the upper end face of the storage tank, and the mud inlet pipe extending into the interior of the central feed cylinder; a reflector plate disposed directly below the central feed cylinder, the reflector plate being fixed to the central feed cylinder by several support rods; an inclined plate assembly disposed around the periphery of the central feed cylinder; a toothed overflow weir having an annular structure and being fixed to the inner wall of the storage tank, the toothed overflow weir being located above the inclined plate assembly; and an overflow pipe fixed to the outer wall of the storage tank and communicating with the toothed overflow weir. This effectively increases the mud settling effect and improves the solidification efficiency through pre-concentration of the mud.

[0006] CN107473555A discloses a sludge thickening tank, including a tank body placed on support legs. The tank body has a sludge inlet device on its side wall and a sludge discharge pipe at its bottom. The sludge inlet device includes a sludge inlet pipe, a sludge guide pipe, and a reflector plate. The sludge inlet pipe is horizontally positioned and perpendicular to the sludge guide pipe, with the guide pipe located at the center of the tank body. The reflector plate is inverted and funnel-shaped, placed at the bottom of the guide pipe. The guide pipe has strip-shaped slots on its side wall, each containing a buffer plate arranged at an angle. An outlet is also provided on the upper part of the tank body's side wall. This thickening tank effectively slows down the rate at which sludge enters the tank, preventing splashing and reducing the settling time required for thickening.

[0007] Existing sludge thickening tanks and sludge thickening olefins still suffer from problems such as low sludge thickening efficiency, difficulty in sludge discharge when the settling time is long, and failure of the sludge moisture content to meet the standards. There is an urgent need to design a high-efficiency sludge thickening system. Summary of the Invention

[0008] The technical problem solved by this invention is to address the issues of low sludge thickening efficiency and poor sludge discharge in the prior art, and to provide a sludge thickening tank, a thickening system and its application method.

[0009] In a first aspect, the present invention provides a sludge thickening tank, comprising:

[0010] The tank body is divided into a gas collection zone, a sedimentation zone and a sludge storage zone from top to bottom. The gas collection zone is equipped with a gas outlet. The sedimentation zone is cylindrical and equipped with a sludge feed pipe. The sedimentation zone is equipped with a drain pipe at the top. The sludge storage zone is inverted conical and equipped with a sludge discharge pipe at the bottom.

[0011] A cyclone internal component is installed in the sedimentation zone. The cyclone internal component is a cylindrical body with a diameter decreasing from top to bottom. The bottom opening is a sludge outlet, and the top is closed and has a clear liquid outlet. The side wall of the cyclone internal component has a feed inlet that is connected to the sludge feed pipe.

[0012] In a second aspect, the present invention provides a sludge thickening system, comprising a sludge primary separation device, the aforementioned sludge thickening tank, and a sludge dewatering device connected in sequence.

[0013] The primary sludge separation equipment, from top to bottom, includes:

[0014] The swirl section is cylindrical, with an inlet and an overflow outlet at the top and a guide plate on the inner wall.

[0015] The narrowing section is an inverted cone shape, and its top is connected to the bottom of the swirl section.

[0016] The collecting section is cylindrical with an outlet at the bottom and a mudguard inside, which is located below the bottom opening of the narrowing section.

[0017] Thirdly, the present invention provides a sludge thickening method. Using the above-mentioned sludge thickening system, sludge slurry enters the primary sludge separation device through the inlet. Under the action of the guide plate, a vortex is formed in the vortex section. The sludge settles due to centrifugal force. The clear liquid after preliminary separation is discharged from the overflow port. The sludge slurry with reduced water content enters the sludge thickening tank and enters the vortex internals tangentially to form a vortex. Under the action of centrifugal sedimentation, gas-liquid-solid separation is carried out. The clear liquid discharged from the clear liquid outlet enters the sedimentation zone for further sedimentation. The gas outlet discharges waste gas and the clear liquid is discharged through the drain pipe. The settled sludge enters the sludge storage area through the bottom outlet of the vortex internals and the thickened sludge is discharged through the bottom sludge discharge pipe. The separated thickened sludge enters the sludge dewatering device for further drying and discharge.

[0018] Preferably, sludge with a relatively high moisture content is introduced into the mixing internals, or a small amount of relatively clear wastewater is introduced to disturb the settled sludge, so that the settled sludge is mixed more evenly and is easier to discharge.

[0019] Compared with the prior art, the beneficial effects of the sludge thickening tank, sludge thickening system and method provided by the present invention are as follows:

[0020] The sludge thickening tank provided by this invention features an internal vortex component, eliminating the need for moving equipment. This effectively improves the flow and distribution characteristics of sludge, achieving efficient separation of sludge and water, thus concentrating the sludge and ensuring the discharge of clarified liquid after settling and the uniform collection of concentrated sludge. The sludge thickening tank can also collect gas for deodorization. It boasts high operating and separation efficiency.

[0021] The sludge thickening system provided by this invention initially separates water from the sludge using a primary sludge separation device, reducing the processing capacity and volume of the subsequent sludge thickening tank, thereby shortening the sludge thickening time. The sludge thickening system provided by this invention can operate intermittently or continuously, increasing the sludge settling rate and enabling rapid separation of sludge and supernatant. Sludge dewatering is further processed using a filter press or centrifuge, rendering the sludge non-fluid and facilitating disposal and transportation. Attached Figure Description

[0022] Figure 1 A schematic diagram of the sludge thickening tank provided by the present invention.

[0023] Figure 2 This is a cross-sectional view of the swirl internals in the sludge thickening tank (AA section).

[0024] Figure 3 This is a structural schematic diagram of one embodiment of a concrete internal component.

[0025] Figure 4 A schematic diagram of the sludge thickening system provided by the present invention.

[0026] Figure 5 This is a schematic diagram of a primary sludge separation device.

[0027] Figure 6 This is a schematic diagram of the sludge thickening tank (tank) in Comparative Examples 1 and 2.

[0028] Explanation of reference numerals in the attached figures

[0029] 1-Tank body 2-Swirl internals 3-Concrete internals

[0030] 4-Gas collection zone; 5-Sedimentation zone; 6-Sludge storage zone

[0031] 7-Gas outlet; 8-Sludge feed pipe; 9-Sludge discharge pipe

[0032] 11-Baffle plate 12-Drain pipe 13-Overflow weir

[0033] 14-Main Concrete Main Pipe 15-Main Concrete Branch Pipe 16-Clear Liquid Outlet

[0034] 21-Swirl section 22-Guide plate 23-Inlet pipe

[0035] 24-Overflow outlet 25-Reduced diameter section 26-Collection section

[0036] 27-Mudguard 28-Outlet

[0037] 10-Homogenizing tank; 20-Primary sludge separation equipment; 30-Sludge thickening tank

[0038] 40 - Sludge dewatering equipment; 31, 32, 33 - Pipelines Detailed Implementation

[0039] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0040] In this application, the terms "upper part," "lower part," and "bottom" are all based on the relative positional relationship of the container or component. Specifically, "bottom" refers to the position of the container from bottom to top of 0-10%, and "top" refers to the position of the container from bottom to top of 90-100%.

[0041] In this invention, unless otherwise specified, the cross-sectional area refers to the area of ​​the cross-section perpendicular to the axial direction.

[0042] In a first aspect, the present invention provides a sludge thickening tank, comprising:

[0043] The tank body is divided into a gas collection zone, a sedimentation zone and a sludge storage zone from top to bottom. The gas collection zone is equipped with a gas outlet. The sedimentation zone is cylindrical and equipped with a sludge feed pipe. The sedimentation zone is equipped with a drain pipe at the top. The sludge storage zone is inverted conical and equipped with a sludge discharge pipe at the bottom.

[0044] A cyclone internal component is installed in the sedimentation zone. The cyclone internal component is a cylindrical body with a diameter decreasing from top to bottom. The bottom opening is a sludge outlet, and the top is closed and has a clear liquid outlet. The side wall of the cyclone internal component has a feed inlet that is connected to the sludge feed pipe.

[0045] In this invention, the swirl internal component is composed of a straight section, a narrowing section, and an expanding section from top to bottom. The height ratio of the straight section, the narrowing section, and the expanding section along the axial direction is 1-3:6-14:1; the inner diameter ratio of the bottom of the straight section, the narrowing section, and the expanding section is 5-10:1:1.2-5.

[0046] The height ratio of the straight section, the reduced diameter section, and the enlarged section along the axial direction is 1-2:8-12:1; the ratio of the inner diameter of the bottom of the straight section, the reduced diameter section, and the enlarged section to the bottom of the enlarged section is 6-8:1:1.3-4.

[0047] Preferably, the included angle β between the straight section and the reduced diameter section is 100°-175°, more preferably 150°-170°.

[0048] In this invention, preferably, a baffle plate 11 is provided below the bottom opening of the swirling internal component, and the swirling internal component and the baffle plate are coaxially arranged; the ratio of the diameter of the baffle plate to the inner diameter of the bottom opening of the swirling internal component is 0.8-1.4:1, preferably 1-1.3:1; the distance from the top of the baffle plate to the bottom of the swirling internal component is 0.1-0.8m, preferably 0.12-0.5m;

[0049] Preferably, the baffle is conical with a cone angle of 60°-87.5°, more preferably 75°-80°. In this application, the "cone angle" refers to the angle between the conical surface and the axis of the cone.

[0050] Preferably, an overflow weir 13 is provided on the outer wall of the swirling internal component below the drain pipe, and the overflow weir is sawtooth shaped.

[0051] Preferably, a sludge removal screen is provided above the clear liquid outlet of the cyclone internal component.

[0052] In this invention, a gas outlet 7 is provided at the top and / or side of the gas collection area. The gas outlet occupies 1%-50% of the top area of ​​the gas collection area. In the swirling internal component, the feed pipe is axially tangent to the inner wall of the swirling internal component; the height of the clear liquid outlet extending into the straight section is 0.2-0.8 times the diameter of the straight section.

[0053] Preferably, a sludge mixing internal component is provided within the sludge storage area. This component comprises a main sludge mixing pipe and multiple branch pipes communicating with the main sludge mixing pipe, with the inlet of the main sludge mixing pipe extending out of the tank body. Preferably, there are 2-8 branch pipes, more preferably 3-4.

[0054] The present invention provides a method for using a sludge thickening tank. Sludge slurry enters the sludge thickening tank and enters the cyclone internals tangentially to form a cyclone. Under centrifugal sedimentation, gas-liquid-solid separation is carried out. The clear liquid discharged from the clear liquid outlet enters the sedimentation zone for further sedimentation. Waste gas is discharged from the gas outlet at the top and clear liquid is discharged through the liquid discharge pipe. Sludge with reduced water content enters the sludge storage zone from the bottom outlet of the cyclone internals and the thickened sludge is discharged through the bottom sludge discharge pipe.

[0055] In a second aspect, the present invention provides a sludge thickening system, comprising a sludge primary separation device, the aforementioned sludge thickening tank, and a sludge dewatering device connected in sequence.

[0056] The primary sludge separation equipment, from bottom to top, includes:

[0057] The swirl section is cylindrical in shape, with an inlet pipe and an overflow port at the top and a guide plate on the inner wall.

[0058] The narrowing section is an inverted cone shape, and its top is connected to the bottom of the swirl section.

[0059] The collecting section is cylindrical with an outlet at the bottom and a mudguard inside, which is located below the bottom opening of the narrowing section.

[0060] The sludge dewatering equipment can be conventionally used sludge dewatering equipment in the art, such as belt filter presses, centrifugal dewatering machines, plate and frame filter presses, etc. Preferably, the sludge dewatering equipment is selected from filter presses or centrifuges, and more preferably hydraulic filter presses or screw press sludge dewatering machines.

[0061] Thirdly, the present invention provides a sludge thickening method. Using the above-mentioned sludge thickening system, sludge slurry enters the primary sludge separation device through the inlet. Under the action of the guide plate, a vortex is formed in the vortex section. The sludge settles due to centrifugal force. The clear liquid after preliminary separation is discharged from the overflow port. The sludge slurry with reduced water content enters the sludge thickening tank and enters the vortex internals tangentially to form a vortex. Under the action of centrifugal sedimentation, gas-liquid-solid separation is carried out. The clear liquid discharged from the clear liquid outlet enters the sedimentation zone for further sedimentation. The gas outlet at the top discharges waste gas, and the clear liquid is discharged through the drain pipe. The sludge with reduced water content enters the sludge storage area through the bottom outlet of the vortex internals. The concentrated sludge is discharged through the bottom sludge discharge pipe. The separated concentrated sludge enters the sludge dewatering device for further drying and discharge.

[0062] After concentration, the sludge is further processed using a filter press or a screw press sludge dewatering machine to remove the sludge's flow dynamics, making it easier to dispose of and transport.

[0063] In one embodiment of the present invention, the sludge to be treated has a moisture content of 97%-99.9%. Preliminary separation is performed in a sludge preliminary separation device with a residence time of 5 min-1 h, resulting in a reduced moisture content of 96.5%-99.5% for the sludge sludge obtained after preliminary separation. Further gas-liquid-solid separation is then performed in a sludge thickening tank with a residence time of 20 min-12 h, resulting in a concentrated sludge with a moisture content of 91%-94%. Further drying treatment is then performed in a sludge dewatering device with a residence time of 30 min-12 h, resulting in a dried sludge with a moisture content generally of 75%-85%.

[0064] The sludge thickening system provided by this invention includes an inlet pipe on the side wall of a cylindrical section in a primary sludge separation device, the axial direction of which is tangent to the side wall of the cylindrical section. The guide plate can be straight or spiral-shaped, and the baffle plate can be conical, umbrella-shaped, or flat. In a preferred embodiment, four guide plates are arranged spirally downwards. The baffle plate is a disc with its edges pointing downwards.

[0065] The application method of the primary sludge separation equipment is as follows: Sludge slurry enters the vortex section tangentially through the inlet pipe. Under the action of the guide plates, it swirls downwards. The clear liquid is discharged from the top overflow port, while the sludge with reduced water content enters the narrowing section and further enters the collection section. Mud baffles prevent the settled sludge from moving upwards, and it enters the next unit through the sludge outlet. In the primary sludge separation equipment, the centrifugal force generated by high-speed rotation enhances sludge-water separation, initially separating some of the clear liquid and reducing the amount of sludge entering subsequent units.

[0066] In one embodiment of the present invention, the diameter of the inlet pipe of the primary sludge separation device is 7%-30% of the diameter of the swirl section, the diameter of the overflow outlet is 10%-40% of the diameter of the swirl section, and the diameter of the bottom outlet of the collection section is 5%-50% of the diameter of the swirl section. The height of the swirl section is 10%-50% of the total height of the primary sludge separation device, the diameter reduction section is an inverted cone shape, and the included angle α between the walls of the swirl section and the diameter reduction section is 100-170 degrees. A guide plate is provided on the inner wall of the swirl section; the guide plate shape can be a straight plate or a spiral ribbon shape; in a preferred embodiment, there are four guide plates arranged spirally downwards. The collection section is cylindrical, and a baffle plate is provided inside the collection section; the baffle plate shape can be conical, umbrella-shaped, or flat, and the baffle plate is a disc shape with its edges facing downwards; the area of ​​the baffle plate occupies 30-70% of the cross-sectional area of ​​the collection section.

[0067] In the sludge thickening system of the present invention, there may be one or more primary sludge separation devices, which are connected in series or parallel to each other and then connected to the sludge thickening tank. The sludge slurry to be treated is obtained after primary treatment by passing through the primary sludge separation devices.

[0068] In one embodiment of the present invention, the upper part and / or the upper side of the sludge thickening tank is provided with at least one gas outlet, which is located on the upper part and / or the side of the gas collection area. A swirling internal component is provided in the sedimentation zone. The cylindrical body of the swirling internal component consists of a straight section, a narrowing section, and an expanding section. The straight section has a feed inlet on its side wall, a closed top with a clear liquid outlet extending into the straight section, and a sludge outlet at the bottom. The height ratio of the straight section, the narrowing section, and the expanding section is 1-2:8-12:1; the ratio of the inner diameter of the bottom of the straight section, the narrowing section, and the expanding section is 6-8:1:1.3-4; the included angle β between the walls of the straight section and the narrowing section is 100°-175°, preferably 150°-170°.

[0069] After the sludge to be treated enters the sludge thickening tank through the sludge feed pipe, it enters the cyclone internals tangentially. A vortex is formed in the straight section and the narrowing section, and the flow velocity decreases slightly in the expanding section to avoid excessive impact on the settling sludge layer. Subsequently, the clear liquid flows upward through the clear liquid outlet, while the heavier sludge settles downward. In one embodiment of the invention, a baffle plate is provided below the outlet of the cyclone internals. The baffle plate is coaxially arranged with the cyclone internals and is conical. The diameter of the bottom of the cone is 0.8-1.4 times that of the outlet of the cyclone internals, preferably 1-1.3 times, and the cone angle is 60°-87.5°, preferably 75°-85°. The distance between the baffle plate and the outlet of the cyclone internals is 0.1-0.8m, preferably 0.12-0.5m. The baffle plate is fixed to the expanding section of the cyclone internals by several support rods. Lighter water and sludge are flushed upwards and settle again after passing through the baffle plate.

[0070] In one embodiment of the present invention, the overflow weir is an annular plate-like structure surrounding the swirling inner component and is fixed to the outer wall of the swirling inner component by a bracket. Preferably, the top of the overflow weir is serrated. The drain pipe is connected to the outer wall of the sludge thickening tank. The clarified liquid flows through the serrated overflow weir and is discharged through the drain pipe.

[0071] In one embodiment of the present invention, a sludge mixing internal component is provided in the sludge storage area in the lower part of the tank, and a sludge discharge pipe is provided at the bottom or lower end of the tank. The sludge storage area has a conical structure with an inclination angle of 35°-70°, preferably 40°-60°, where the inclination angle refers to the angle between the inclined surface of the sludge storage area and the horizontal plane. The sludge discharge pipe can be connected to the bottom of the cone. The sludge storage area is provided with a sludge mixing internal component, which preferably consists of a central pipe and branch pipes. The sludge or sludge raw material is introduced through the central pipe and then discharged through the branch swirl pipes, which is used to disturb the bottom settling sludge, thereby making the mixing more uniform and easier to discharge.

[0072] The specific embodiments of the sludge thickening tank and sludge thickening system provided by the present invention will be clearly and completely described below with reference to the accompanying drawings. However, the accompanying drawings and embodiments do not constitute a limitation of the present invention.

[0073] Appendix Figure 1 A schematic diagram of a preferred embodiment of a sludge thickening tank is attached. Figure 1 As shown, the sludge thickening tank is divided into a gas collection zone 4, a sedimentation zone 5, and a sludge storage zone 6 from top to bottom. The gas collection zone has multiple gas outlets 7 at the top. The sedimentation zone has a sludge feed pipe 8 on its side wall and a drain pipe 12 on its upper side wall. The sedimentation zone also has a vortex internal component 2. (See attached image) Figure 2 This is a cross-sectional view (AA) of the swirl internal components in the sludge thickening tank. (See attached diagram.) Figure 1 , 2 As shown, the cyclone internal component 2 is a cylindrical body with a decreasing diameter from top to bottom. The top is closed and has a clear liquid outlet 16. The feed inlet on the side wall of the cyclone internal component is connected to the sludge feed pipe 8. The bottom opening is a sludge discharge pipe. Below the bottom opening of the cyclone internal component is a baffle plate 11, which is conical in shape. The ratio of the baffle plate diameter to the inner diameter of the bottom opening of the cyclone internal component is 0.8-1.4:1. The cyclone internal component and the baffle plate are coaxially arranged. The sludge storage area is an inverted cone shape, and a sludge mixing internal component 3 is installed within the sludge storage area. The inlet of the sludge mixing main pipe extends out of the tank body. A sludge discharge pipe 9 is located at the bottom of the sludge storage area.

[0074] Appendix Figure 3 This is a structural schematic diagram of one embodiment of a concrete internal component. (See attached diagram.) Figure 3 As shown, the concrete internals consist of a main concrete pipe 14 and four branch concrete pipes 15 connected to the main concrete pipe. The swirl internals, baffles, and concrete internals are coaxially arranged.

[0075] Appendix Figure 4 This is a schematic diagram of the sludge thickening system. (See attached diagram.) Figure 4 As shown, the sludge thickening system includes a primary sludge separation device 20, a sludge thickening tank 30, and a sludge dewatering device 40 connected in sequence. Sludge slurry from the homogenizing tank 10 undergoes preliminary dewatering in the primary sludge separation device. The separated clear liquid is discharged through pipeline 32. The sludge slurry with reduced water content enters the sludge thickening tank 30 for further separation of the gas, liquid, and solid phases. The separated gas is discharged through pipeline 31 for further processing. The separated clear liquid is discharged from the drain pipe of the sludge thickening tank and then through pipeline 32 for further processing. The thickened sludge is discharged from the sludge discharge pipe 9 at the bottom of the sludge thickening tank and enters the sludge dewatering device 40 for further drying. The sludge dewatering device can be a filter press or a centrifuge. The resulting dried sludge is discharged through pipeline 33.

[0076] Appendix Figure 5 This is a schematic diagram of a primary sludge separation device. (See attached diagram) Figure 5 As shown, the primary sludge separation equipment consists of a swirl section 21, a narrowing section 25, and a collection section 26 from top to bottom. The swirl section is cylindrical, with an inlet pipe 23 on the side wall, an overflow port 24 on the top, and a guide plate 22 on the inner wall. The collection section is cylindrical, with an outlet 28 at the bottom. Inside the collection section, a baffle plate 27 is provided below the bottom opening of the narrowing section to prevent the sludge from flowing directly downwards.

[0077] The following examples will further illustrate the technical effects of the sludge thickening tank, sludge thickening system and application method provided by the present invention, but the present invention is not limited thereto.

[0078] In this embodiment, the sludge to be treated was taken from the wastewater treatment workshop of Sinopec Refining & Chemical Co., Ltd., and its properties are shown in Table 1.

[0079] Comparative Example 1

[0080] Comparative Example 1 illustrates the intermittent sludge settling and thickening process. A schematic diagram of the sludge thickening tank is attached. Figure 6 As shown, the upper part is cylindrical, the lower part is inverted conical, and the bottom is the concentrated sludge outlet. The top is sealed with a central pipe inlet 8, and the top perimeter has a clear liquid outlet 16 via an overflow weir 13. The sludge thickening tank has a diameter of 6400 mm and a height of 3500 mm. The diameter of the central pipe inlet is 260 mm, and the central pipe extends 400 mm into the tank. The sludge to be treated is pumped into the central pipe inlet by a sludge pump. After settling in the sludge thickening tank, the sludge is discharged from the bottom of the thickening tank, and the separated clear liquid is discharged through the clear liquid outlet 16 via an overflow weir. The properties of the sludge to be treated are shown in Table 1, with a moisture content of 99.2%. The moisture content after thickening is shown in Table 2. When the settling time is long, sludge discharge is not smooth.

[0081] Example 1

[0082] Example 1 uses the sludge thickening tank of the present invention for intermittent sludge thickening. The sludge slurry to be treated from the outlet of the homogenizer enters the sludge thickening tank. The tank body consists of a gas collection zone 4, a sedimentation zone 5, and a sludge storage zone 6 from top to bottom. The sedimentation zone has a diameter of 4000 mm and a height of 6000 mm. The sludge slurry first enters the cyclone internals through the sludge feed pipe. In the cyclone internals, the inner diameter of the cyclone section is 500 mm, the bottom inner diameter of the narrowing section is 100 mm, the included angle β is 160 degrees, and the bottom inner diameter of the expanding section is 130 mm. The height ratio of the three sections—cyclone section, narrowing section, and expanding section—is 2:10:1. The baffle plate below the outlet is conical with a diameter of 160 mm and a cone angle of 75 degrees, and is 200 mm away from the outlet of the cyclone internals. After further separation of sludge and water, the sludge enters the sludge storage zone, which is 1000 mm high and has an inclination angle of 50 degrees. The upper clear liquid is discharged through the overflow weir and drain outlet. Four gas outlets, each 50mm in diameter, are provided in the top gas collection area for waste gas collection. A sludge mixing internal system is installed in the sludge storage area, consisting of a main mixing pipe and three branch mixing pipes. A small amount of wastewater is pumped into the tank to agitate the deposited sludge layer, facilitating smoother sludge discharge. The same method can also be used to flush the sludge discharge pipeline. The sludge settling results and settling time are shown in Table 2.

[0083] Example 2

[0084] The sludge used in Example 2 is the same as that in Example 1, except that the sludge from the homogenizing tank first enters the primary separation device for separation. The structure of the primary separation device is shown in the attached figure. Figure 5 As shown, the primary separation equipment consists of a vortex section, a narrowing section, and a collection section from top to bottom. The vortex section has a diameter of 300 mm and a height of 400 mm. The overflow port at the top of the vortex section has a diameter of 90 mm, and the outlet diameter at the bottom of the collection section is 50 mm. The total height of the primary separation equipment is 1500 mm. Guide plates are installed on the inner wall of the vortex section, and the guide plates are spiral-shaped. A baffle plate is installed inside the collection section; the baffle plate is a disc with its edges facing downwards, and its area is 50% of the cross-sectional area of ​​the collection section. After separation by the primary separation equipment, the sludge slurry obtained has a primary treatment content of 98% and a volume approximately 50% of the original sludge slurry. The primary treated sludge slurry enters the sludge thickening tank, which uses the same structure as in Example 1. The volume of sludge to be treated is approximately half of the original, thus significantly reducing the sludge thickening time while maintaining the same settling effect. The sludge settling results and settling time are shown in Table 2.

[0085] As can be seen from the data in Table 2, during intermittent operation, the sludge thickening system provided by this invention can reduce sludge settling time, improve sludge thickening efficiency, and ensure smooth sludge discharge, enabling the sludge thickening system to operate stably.

[0086] Table 1 Properties of the sludge to be treated

[0087]

[0088]

[0089] Table 2. Moisture content and settling time of sludge before and after thickening.

[0090] Comparative Example 1 Example 1 Example 2 Inlet moisture content, % 99.2 99.1 99.1 Export moisture content, % 93.6 93.2 93.0 Settling time, h 12 8 6

[0091] Comparative Example 2

[0092] Comparative Example 2 adopts the method shown in the appendix. Figure 6 The sludge thickening tank shown has a cylindrical upper section and an inverted conical lower section, with the thickened sludge outlet at the bottom. A central pipe inlet 8 is sealed at the top, and a clear liquid outlet 16 is located around the top perimeter via an overflow weir 13. The sedimentation zone in the upper part of the settling tank has a diameter of 2000 mm and a height of 3760 mm. The central pipe has a diameter of 240 mm, and the central pipe inlet extends 1800 mm into the tank. Continuous sludge settling and thickening operation is adopted. The sludge to be treated is pumped into the central pipe inlet by a sludge pump. The settling tank uses hydrostatic pressure to discharge sludge, and the supernatant is discharged through the peripheral outlet. The properties of the sludge to be treated are shown in Table 3. The sludge settling results are shown in Table 4.

[0093] Example 3

[0094] In Example 3, the sludge slurry to be treated was fed the same as in Comparative Example 2. The sludge slurry from the homogenizer was directly fed into the feed as shown in the attached figure. Figure 1 The sludge thickening tank shown has an internal structure consisting of a gas collection zone 4, a sedimentation zone 5, and a sludge storage zone 6, arranged from top to bottom. The sedimentation zone has a diameter of 1800 mm and a height of 4500 mm. The sludge to be treated first enters the cyclone internals through the sludge feed pipe. The cyclone internals consist of a straight section, a narrowing section, and an expanding section, arranged from top to bottom. The straight section has an inner diameter of 350 mm, the bottom inner diameter of the narrowing section is 50 mm, and the bottom inner diameter of the expanding section is 70 mm. The angle β between the straight section and the narrowing section is 75 degrees. A baffle plate with a diameter of 90 mm is located below the bottom opening of the cyclone internals and is 200 mm away from the outlet of the cyclone internals. After sedimentation and separation, the sludge enters the sludge storage zone 6, which is 1000 mm high and inclined at 50 degrees. The upper clear liquid is discharged through an overflow weir and a drain pipe. The top gas collection zone has four gas outlets for waste gas collection, each with an inner diameter of 50 mm. The sludge settling results are shown in Table 4.

[0095] Table 3 Properties of the sludge to be treated

[0096] <![CDATA[Sludge particle density, kg / m 3 > 1051 Sludge particle dynamic viscosity, Pas 0.02 Average particle diameter, μm 10 Solid phase volume fraction of fluid 3％ <![CDATA[Liquid density, kg / m 3 > 1000 Liquid phase dynamic viscosity, Pas 0.001

[0097] Table 4 Moisture content of sludge before and after thickening

[0098] Comparative Example 2 Example 3 Inlet moisture content, % 97 97 Export moisture content, % 92.2 91.3 Settling time, min 70 30

[0099] As shown in Table 4, when using the sludge thickening tank provided by the present invention, the settling time is shortened by about 57% under the same processing capacity during continuous operation, which can effectively improve the thickening efficiency.

Claims

1. A sludge thickening tank, characterized in that, include: The tank body (1) consists of a gas collection area (4), a sedimentation area (5) and a sludge storage area (6) from top to bottom. The gas collection area is provided with a gas outlet (7). The sedimentation area is provided with a sludge feed pipe (8) on the side wall and a drain pipe (12) at the top. The sludge storage area is inverted cone-shaped and has a sludge discharge pipe (9) at the bottom. The swirling internal component (2) is set in the sedimentation zone. The swirling internal component is a cylindrical body with a diameter decreasing from top to bottom. The bottom opening is a slurry outlet, and the top is closed and has a clear liquid outlet (16). The side wall of the swirling internal component has a feed inlet that is connected to the sludge feed pipe.

2. The sludge thickening tank according to claim 1, characterized in that, The swirl internal component consists of a straight section, a narrowing section, and an expanding section from top to bottom. The height ratio of the straight section, the narrowing section, and the expanding section along the axial direction is 1-3:6-14:1; the inner diameter ratio of the bottom of the straight section, the narrowing section, and the expanding section is 5-10:1:1.2-5. Preferably, the height ratio of the openings of the straight section, the reduced diameter section, and the enlarged section is 1-2:8-12:1; the ratio of the inner diameter of the bottom of the straight section, the reduced diameter section, and the enlarged section to the bottom of the enlarged section is 6-8:1:1.3-4. Preferably, the included angle β between the straight section and the reduced diameter section is 100°-175°, more preferably 150°-170°.

3. The sludge thickening tank according to claim 1 or 2, characterized in that, A baffle plate (11) is provided below the bottom opening of the swirling internal component, and the swirling internal component and the baffle plate are coaxially arranged; the ratio of the diameter of the baffle plate to the inner diameter of the bottom opening of the swirling internal component is 0.8-1.4:1, preferably 1-1.3:1; the distance from the top of the baffle plate to the bottom outlet of the swirling internal component is 0.1-0.8m, preferably 0.12-0.5m; Preferably, the baffle is conical with a cone angle of 60°-87.5°, more preferably 75°-80°.

4. The sludge thickening tank according to claim 3, characterized in that, An overflow weir (13) is provided on the outer wall of the swirling internal component below the drain pipe, and the overflow weir is sawtooth shaped; Preferably, a sludge removal screen is provided above the clear liquid outlet of the cyclone internal component.

5. The sludge thickening tank according to any one of claims 1-4, characterized in that, The gas collection area is provided with a gas outlet (7) on the top and / or side.

6. The sludge thickening tank according to any one of claims 1-4, characterized in that, In the aforementioned swirling internal component, the feed inlet is tangent to the inner wall of the swirling internal component along its axis; the height of the clear liquid outlet extending into the straight section of the cylinder is 0.2-0.6 times the diameter of the straight section.

7. The sludge thickening tank according to any one of claims 1-4, characterized in that, The sludge storage area is provided with a sludge mixing internal component (3), which consists of a sludge mixing main pipe (14) and multiple sludge mixing branch pipes (15) connected to the sludge mixing main pipe. The sludge mixing main pipe extends out of the sludge thickening tank. Preferably, there are 2-8 concrete branch pipes, more preferably 3-4.

8. A sludge thickening system, characterized in that, Includes primary separation devices connected in sequence. (20) The sludge thickening tank (30) and sludge dewatering equipment (40) according to any one of claims 1-5; The primary separation device, from top to bottom, includes: The swirl section (21) is cylindrical, with an inlet pipe (23) on the side wall, an overflow port (24) on the top, and a guide plate (22) installed on the inner wall. The narrowing section (25) is an inverted cone shape, and its top is connected to the bottom of the swirl section; The collecting section (26) is cylindrical and has a mudguard (27) inside. The mudguard is located below the bottom opening of the narrowing section and has an outlet (28) at the bottom.

9. The sludge thickening system according to claim 8, characterized in that, In the primary sludge separation equipment, the diameter of the inlet pipe is 7%-30% of the diameter of the cyclone section, the diameter of the overflow outlet is 10%-40% of the diameter of the cyclone section, and the diameter of the bottom outlet of the collection section is 5%-50% of the diameter of the cyclone section. The diameter and height of the cyclone section are 10%-50% of the total height of the primary sludge separation equipment, and the included angle α between the cyclone section and the pipe wall of the narrowing section is 100-170 degrees. Preferably, the area of ​​the mudguard accounts for 30-70% of the cross-sectional area of ​​the collection section.

10. The sludge thickening system according to claim 8 or 9, characterized in that, The sludge dewatering equipment is selected from a filter press or a centrifuge, with a filter press being preferred.

11. A method for sludge thickening, characterized in that, Using the sludge thickening system described in claim 8 or 9, the sludge to be treated enters the primary sludge separation equipment through the inlet. Under the action of the guide plate, a vortex is formed in the vortex section. The sludge settles due to centrifugal force. The clear liquid after preliminary separation is discharged from the overflow port. The sludge with reduced water content enters the sludge thickening tank and enters the vortex internals tangentially to form a vortex. Under the action of centrifugal sedimentation, gas-liquid-solid separation is carried out. The clear liquid discharged from the clear liquid outlet enters the sedimentation zone for further sedimentation. The gas outlet discharges waste gas, and the clear liquid is discharged through the drain pipe. The sludge enters the sludge storage area through the bottom outlet of the cyclone internals, and the concentrated sludge is discharged through the bottom sludge discharge pipe; the separated concentrated sludge enters the sludge dewatering equipment for further drying and discharge.

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