Clarifier

Abstract

The utility model belongs to the field of clarifiers, and particularly discloses a clarifier which comprises a barrel and a central downcomer arranged in the barrel, and the central downcomer sequentially comprises an air separation section, a transition section, a downcomer middle section and a water distribution section from top to bottom; the longitudinal section of the transition section is trapezoidal, and the diameter is gradually reduced; the longitudinal section of the water distribution section is trapezoidal, the diameter of the water distribution section is gradually increased, and the maximum diameter of the water distribution section is at least twice the diameter of the air separation section. According to the scheme, the structure of the central downcomer is improved, the design of the variable pipe diameter is combined, and the design characteristics that the pipe diameter is reduced or suddenly and greatly increased and the like are utilized, so that the sludge settling effect is ensured; meanwhile, the end part of the water distribution section is arranged to be saw-toothed, so that the mud-water separation effect is enhanced; besides, in combination with the design of the sludge return pipe, the contact between the sludge is increased, the flocculation effect between the sludge is realized through the funnel, and the flocculated sludge is high in precipitation speed and good in precipitation effect, so that the stable effluent quality is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of clarifiers, and particularly relates to a clarifier with an improved central downcomer and a sludge backflow pipe. BACKGROUND

[0002] The clarifier is a water treatment device integrating coagulation and sedimentation, and is mainly used for treating suspended solids in wastewater.

[0003] In the prior art, the central downcomer of the clarifier for treating desulfurization wastewater is generally designed to have the same size of inlet and outlet pipe diameters, which causes the following problems: the water flow rate of the central downcomer is high, which impacts the sludge, resulting in turbid effluent; the air and water cannot be separated due to the same upper and lower pipe diameters, which causes the air to drive the sludge to float, seriously affecting the wastewater treatment effect; in addition, the existing clarifier does not have a sludge backflow pipe design, and the sludge cannot backflow, affecting the flocculation effect.

[0004] In summary, due to the high solid content of desulfurization wastewater and the air contained in the influent, if the air and water are not separated and the water flow rate of the central downcomer is high, and the sludge cannot backflow, the flocculation effect will be affected, the effluent of the clarifier will be turbid, and the water quality will exceed the standard. SUMMARY

[0005] In the field of desulfurization wastewater treatment, in order to solve the problems of air and water not being separated and turbid effluent caused by the clarifier having the same size of inlet and outlet pipe diameters in the prior art, a clarifier is provided, which is improved in design of the central downcomer to improve the sludge and water separation effect.

[0006] The utility model is implemented by the following technical scheme: a clarifier, comprising a cylinder and a central downcomer arranged in the cylinder, the inside of the cylinder is sequentially divided into a sludge storage layer, a sludge buffer layer, a sludge and water separation layer, and a clear water layer from bottom to top; the upper part of the central downcomer is in communication with the atmosphere, and the lower part is located in the sludge buffer layer; the central downcomer sequentially comprises an air separation section, a transition section, a downcomer middle section, and a water distribution section from top to bottom; the longitudinal section of the transition section is trapezoidal, and the diameter gradually decreases; the longitudinal section of the water distribution section is trapezoidal, and the diameter gradually increases, and the maximum diameter of the water distribution section is at least twice the diameter of the air separation section, and the end of the water distribution section is serrated to enhance the sludge and water separation effect.

[0007] Further, a sludge backflow pipe is arranged on the inner side wall of the cylinder, the sludge backflow pipe comprises a hopper, a backflow pipe, and a support, the hopper is arranged at the upper end of the backflow pipe, the backflow pipe is fixed to the inner wall of the cylinder through the support, the upper part of the sludge backflow pipe is located in the sludge and water separation layer, the lower part is located in the sludge buffer layer, and the position of the bottom end of the sludge backflow pipe is lower than that of the central downcomer, and the sludge backflow pipe is uniformly arranged at 6-12 around the cylinder.

[0008] Further, the central tube down pipe is adjusted by adjusting a pull rod and a positioning steel plate at the top of the cylinder body, one end of the pull rod is welded with the middle section of the down pipe, the other end is welded with the steel beam at the top of the cylinder body, and the positioning steel plate is welded with the steel beam at the top of the clarifier.

[0009] Compared with the prior art, the advantages and positive effects of the utility model are that:

[0010] The present application provides a novel clarifier structure, which improves the structure of the central down pipe, ensures the sludge sedimentation effect through the design of variable pipe diameter, sudden reduction of pipe diameter or sudden large increase of pipe diameter, etc., sets the end of the water distribution section into a sawtooth shape to further enhance the sludge-water separation effect, additionally, adds a sludge backflow pipe to the inner wall of the cylinder body to increase the contact between the sludge and the sludge, and realizes the flocculation between the sludge by combining the funnel design, so that the flocculated sludge has a fast sedimentation speed and good sedimentation effect, thereby ensuring the stable water quality. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 Fig. 1 is a side view of the structure of the clarifier according to the present application;

[0012] Figure 2 Fig. 2 is a structure diagram of the central down pipe according to the present application;

[0013] Figure 3 Fig. 3 is a structure diagram of the sludge backflow pipe according to the present application. DETAILED DESCRIPTION

[0014] In order to more clearly understand the above purpose, features and advantages of the present application, the present application will be further described below in combination with the drawings and embodiments. In the following description, a large number of specific details are set forth in order to fully understand the present application, but the present application can also be implemented in other ways different from those described herein, therefore, the present application is not limited to the specific embodiments disclosed below.

[0015] Embodiments, such as Figure 1The clarifier includes a cylinder 1, a central downcomer 2, and a sludge scraper 3. The central downcomer 2 is located at the top of the cylinder 1, and the sludge scraper 3 is located at the bottom of the cylinder 1. The interior of the cylinder 1 is divided into a sludge storage layer A, a sludge buffer layer B, a sludge-water separation layer C, and a clear water layer D from bottom to top. The upper part of the central downcomer 2 is open to the atmosphere to ensure smooth venting, and the lower part is located in the sludge buffer layer B. The central downcomer 2 includes an air separation section 21, a transition section 22, a middle section 23, and a water distribution section 24 from top to bottom. The diameter of the transition section 22 gradually decreases, and the diameter of the water distribution section 24 suddenly increases. The maximum diameter of the water distribution section 24 is at least twice the diameter of the air separation section 21, and the end of the water distribution section 24 is serrated 25.

[0016] Continue to refer to Figure 1 The central downcomer 2 is fixed to the top of the cylinder 1 by adjusting the tie rod 4 and positioning steel plate 5. One end of the adjusting tie rod 4 is welded to the middle section 23 of the downcomer, and the other end is welded to the top steel beam of the cylinder 1. It is mainly used to fine adjust the central downcomer 2 to ensure verticality. The positioning steel plate 5 is welded to the top steel beam of the clarifier and is evenly distributed along the air separation section 21 in four pieces to fix the central downcomer 2 and ensure that the central downcomer 2 does not shake or deviate.

[0017] In practical operation, the central downcomer operates on the following principle:

[0018] The desulfurization wastewater from the absorption tower contains air due to the action of the oxidation blower, which is detrimental to sludge settling. Therefore, air-water separation is necessary. First, the wastewater enters the air separation section 21. Due to the sharp decrease in flow velocity, the air in the wastewater rises and overflows to the surface, achieving air-water separation and preventing subsequent sludge from floating due to air. It then enters the transition section 22, where the pipe diameter decreases to prevent air from re-entering. Finally, it enters the water distribution section 24 through the middle section 23 of the downcomer. In the water distribution section 24, the pipe diameter suddenly increases significantly, and the flow velocity drops sharply. Because the density of sludge is greater than that of water, most of the sludge settles down, and the low flow velocity prevents surrounding sludge from floating. Furthermore, the serrated edge 25 at the end of the water distribution section 24 further enhances the sludge-water separation effect.

[0019] Combination Figure 1 In this embodiment, a sludge return pipe 6 is also designed. The sludge return pipe 6 consists of a funnel 61, a return pipe 62, and a support 63. The funnel 61 is located at the upper end of the return pipe 62, and the return pipe 62 is fixed to the inner wall of the cylinder 1 by the support 63. The upper part of the sludge return pipe 6 is located in the sludge-water separation layer C, and the lower part is located in the sludge buffer layer B, slightly lower than the central downcomer. Six to twelve sludge return pipes 6 are evenly distributed along the circumference of the cylinder, with the number determined by the diameter of the clarifier. Generally, six pipes are arranged for diameters less than 6 meters, eight for diameters between 6 and 9 meters, and twelve for diameters greater than 9 meters.

[0020] The principle of the sludge return pipe is as follows:

[0021] The wastewater from the central downcomer 2, most of the sludge is separated from the water in the sludge buffer layer. A small amount of sludge with smaller density still continues to float. In the process of floating, mainly rely on gravity to precipitate, the precipitation rate is slow, and the precipitation effect is poor. After adding the sludge return pipe, the contact between the sludge and the sludge is increased, combined with the design of the funnel, the flocculation between the sludge can be realized, the precipitation speed of the flocculated sludge is fast, and the precipitation effect is good, so as to ensure the stable water quality of the effluent.

[0022] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to equivalent embodiments applied to other fields, but any simple modification, equivalent change and modification made on the basis of the technical essence of the present application to the above embodiments shall still fall within the protection scope of the present application.

Claims

1. A clarifier comprising a cylinder (1) and a central downcomer (2) arranged in the cylinder (1), the inside of the cylinder (1) is divided into a sludge storage layer, a sludge buffer layer, a sludge-water separation layer and a clear water layer from bottom to top; the upper part of the central downcomer (2) is communicated with the atmosphere, and the lower part is located in the sludge buffer layer, characterized in that: the central downcomer (2) comprises an air separation section (21), a transition section (22), a downcomer middle section (23) and a water distribution section (24) from top to bottom; the longitudinal section of the transition section (22) is trapezoidal, and its diameter gradually decreases; the longitudinal section of the water distribution section (24) is trapezoidal, and its diameter gradually increases, and the maximum diameter of the water distribution section (24) is at least twice the diameter of the air separation section (21).

2. The clarifier of claim 1, wherein: a sludge backflow pipe (6) is further arranged on the inner side wall of the cylinder (1), the sludge backflow pipe (6) is composed of a hopper (61), a backflow pipe (62) and a bracket (63), the hopper (61) is arranged at the upper end of the backflow pipe (62), and the backflow pipe (62) is fixed on the inner wall of the cylinder (1) through the bracket (63).

3. The clarifier of claim 2, wherein: the upper part of the sludge backflow pipe (6) is located in the sludge-water separation layer, and the lower part is located in the sludge buffer layer, and the position of the bottom end of the sludge backflow pipe (6) is lower than that of the bottom end of the central downcomer (2).

4. The clarifier of claim 2, wherein: 6-12 sludge backflow pipes (6) are evenly arranged along the circumference of the cylinder (1).

5. The clarifier of claim 1, wherein: the end of the water distribution section (24) is serrated (25).

6. The clarifier of claim 1, wherein: the central downcomer (2) is fixed on the top of the cylinder (1) through an adjusting pull rod (4) and a positioning steel plate (5), one end of the adjusting pull rod (4) is welded with the downcomer middle section (23), the other end is welded with the top steel beam of the cylinder (1), and the positioning steel plate (5) is welded with the top steel beam of the clarifier.

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