Crystallizing tank for sewage treatment

Abstract

The utility model discloses a crystallizing tank for sewage treatment, which comprises a base and a crystallizing tank body arranged on the base, and is characterized in that an overflow pipe is arranged at the upper part of the crystallizing tank body, a stirring shaft is arranged in the crystallizing tank body, the stirring shaft is connected with a stirring motor arranged at the upper end of the crystallizing tank body, and the stirring motor is connected with the crystallizing tank body. A stirring piece is arranged at the lower end of the stirring shaft; and a water inlet pipe and a water outlet pipe are arranged at the upper part of the crystallizing tank body. In order to overcome the defects in the prior art, the utility model provides the freezing system which is simple in structure and beneficial to analysis and diversion of salt in sewage, so that the sewage treatment efficiency is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a crystallization tank for sewage treatment. Background Art

[0002] At present, evaporation concentration is generally adopted for difficult-to-treat sewage. Electric, gas, and coal boiler evaporation devices are commonly used at home and abroad. Due to the high operating temperature, large steam pressure, and high requirements for anti-corrosion and pressure resistance of equipment materials, pressure-resistant operation is required, and pressure-bearing equipment is very expensive; the coal boiler evaporation concentration device has been basically phased out or is being phased out due to serious environmental pollution; the gas-heated boiler evaporation concentration device is not widely used at present due to both safety and economic reasons. Due to considerations of convenience and environmental protection, the application of electric heating concentration devices has increased recently. However, the energy consumption of single-stage electric boilers is very high. Even if multi-stage evaporation is adopted, the energy consumption per ton of water for the electric boiler evaporation concentration device is still about 200 kwh - 300 kwh. The equipment investment of the electric boiler evaporation concentration device is high, and the energy consumption is still relatively high. For the MVR steam compression evaporation concentration system, even if multi-stage evaporation concentration is adopted, the energy consumption per ton of water is still as high as 200 kwh, and the process is complex, the equipment requirements are high, and the investment cost is high.

[0003] For the heat pump low-temperature vacuum evaporation concentration system, the energy consumption per ton of water is still as high as 200 kwh. Moreover, the process has vacuum pressure-bearing equipment, the equipment is expensive, and the investment cost is high. Using a heat pump to evaporate and dehumidify and concentrate sewage can evaporate and concentrate sewage at low temperature and normal pressure. The equipment requirements are relatively low, and the investment is less. Moreover, due to the 3 - 4 times energy efficiency improvement of the heat pump, the energy consumption per ton of water can also be reduced to about 200 kwh, but the energy consumption is still relatively high.

[0004] In order to reduce the energy consumption in the sewage treatment process, the prior art has developed a method of sewage treatment by freezing concentration. However, due to the design defects of the existing freezing system, it is difficult for the crystallization tank to separate out salts in the sewage concentrate and effectively precipitate and divert them during the working process. As a result, the sewage treatment efficiency is relatively low.

[0005] Therefore, the existing crystallization tanks for sewage treatment need to be further improved. Summary of the Utility Model

[0006] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a freezing system with a simple structure, which can help separate and divert salts in sewage, thereby effectively improving the sewage treatment efficiency.

[0007] To achieve the above object, the present utility model adopts the following solution: A crystallization tank for sewage treatment, comprising a base, on which a crystallization tank body is provided, characterized in that: an overflow pipe is provided at the upper part of the crystallization tank body, a stirring shaft is provided in the crystallization tank body, the stirring shaft is connected to a stirring motor arranged at the upper end of the crystallization tank body, a stirring member is provided at the lower end of the stirring shaft, and a water inlet pipe and a water outlet pipe are provided at the upper part of the crystallization tank body.

[0008] As another improvement of the crystallization tank for sewage treatment of the present utility model, an annular step is provided in the crystallization tank body, an annular baffle is provided inside the annular step, and the annular step, the annular baffle and the crystallization tank body jointly enclose an overflow channel, and the overflow pipe is communicated with the overflow channel.

[0009] As another improvement of the crystallization tank for sewage treatment of the present utility model, annular teeth are provided at the upper end of the annular baffle.

[0010] As another improvement of the crystallization tank for sewage treatment of the present utility model, a central sleeve is provided inside the upper part of the crystallization tank body, the stirring shaft is arranged in the central sleeve, a diversion channel is formed between the inner wall of the central sleeve and the outer wall of the stirring shaft, the lower end of the central sleeve extends into the lower part of the crystallization tank body, and the water outlet pipe is communicated with the middle part of the central sleeve.

[0011] As another improvement of the crystallization tank for sewage treatment of the present utility model, a flared opening is provided at the lower end of the central sleeve.

[0012] As another improvement of the crystallization tank for sewage treatment of the present utility model, the central sleeve is fixedly arranged on the inner wall of the crystallization tank body through a connecting rod, and the upper end of the central sleeve is arranged on the upper end of the crystallization tank body through a mounting frame.

[0013] As another improvement of the crystallization tank for sewage treatment of the present utility model, the stirring member includes a first stirring cross bar and a second stirring cross bar which are arranged at intervals on the outer wall of the lower end of the stirring shaft from top to bottom, the length of the first stirring cross bar is greater than the length of the second stirring cross bar, and stirring inclined bars are respectively arranged between the ends of the first stirring cross bar and the second stirring cross bar.

[0014] As another improvement of the crystallization tank for sewage treatment of the present utility model, a plurality of reinforcing rings are arranged at intervals on the outer wall of the crystallization tank body.

[0015] As another improvement of the crystallization tank for sewage treatment of the present utility model, a slag discharge port is provided at the lower part of the crystallization tank body.

[0016] As another improvement of a crystallization tank for sewage treatment in the present utility model, a speed reducer is provided between the stirring motor and the stirring shaft.

[0017] In summary, the beneficial effects of the present utility model compared with the prior art are as follows:

[0018] In the present utility model, the sewage concentrate is cooled by an external freezing device, and due to the temperature drop, part of the salts in the liquid precipitate. The salts precipitate and concentrate in the crystallization tank due to gravity, increasing the salt content in the tank. Then the concentrated liquid is pumped away by the bottom concentrated liquid pump and enters the next process. There is an overflow trough at the upper part of the crystallization tank, and the supernatant flows to the next process by gravity. To prevent the salts from accumulating and caking at the bottom, the stirring paddle slowly stirs the bottom, making it easier to be pumped away by the concentrated liquid pump. The structure of the present utility model is simple, which can help to analyze and separate the salts in the sewage, thus effectively improving the sewage treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional schematic diagram of the present utility model.

[0020] Figure 2 is Figure 1 a sectional schematic diagram of

[0021] Figure 3 is Figure 2 an enlarged schematic diagram of part A in

[0022] Figure 4 is Figure 2 an enlarged schematic diagram of part B in

[0023] In the figure: 1, base; 2, crystallization tank body; 3, overflow pipe; 4, stirring shaft; 5, stirring motor; 6, stirring member; 61, first stirring cross bar; 62, second stirring cross bar; 63, stirring inclined bar; 7, water inlet pipe; 8, water outlet pipe; 9, feeding pump; 10, annular step; 11, annular baffle; 12, annular tooth; 13, central sleeve; 14, flared opening; 15, connecting rod; 16, mounting bracket; 17, reinforcing ring; 18, slag discharge port; 19, speed reducer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The following further describes in detail the above and other technical features and advantages of the present utility model with reference to the accompanying drawings.

[0025] The preferred embodiments of the present utility model will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present utility model and do not limit the protection scope of the present utility model.

[0026] It should be noted that in the description of the present utility model, the terms indicating the direction or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0027] In addition, it should be noted that in the description of the present utility model, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] As Figures 1-4 shown, a crystallization tank for sewage treatment includes a base 1. A crystallization tank body 2 is provided on the base 1. An overflow pipe 3 is provided at the upper part of the crystallization tank body 2. A stirring shaft 4 is provided inside the crystallization tank body 2. The stirring shaft 4 is connected to a stirring motor 5 provided at the upper end of the crystallization tank body 2. A stirring member 6 is provided at the lower end of the stirring shaft 4. A water inlet pipe 7 and a water outlet pipe 8 are provided at the upper part of the crystallization tank body 2. A concentrated liquid outlet pipe 20 is provided at the lower part of the crystallization tank body. The concentrated liquid outlet pipe is connected to the feed end of a centrifuge through a concentrated liquid pump.

[0029] In the present invention, the sewage concentrated liquid is passed through an external freezing heat exchanger to lower its temperature. Due to the temperature decrease, some salts in the liquid precipitate. The salts precipitate and concentrate in the crystallization tank due to gravity, increasing the salt content in the tank. Then the concentrated liquid is pumped away by the bottom concentrated liquid pump and enters the next process. There is an overflow pipe at the upper part of the crystallization tank, and the supernatant flows by gravity through the overflow pipe to the next process. The bottom is slowly stirred by the stirring member, effectively preventing the salts from accumulating and caking at the bottom, making it easier to be pumped away by the concentrated liquid pump.

[0030] In the present utility model, an annular step 10 is provided inside the crystallization tank body 2. An annular baffle 11 is provided inside the annular step 10. The annular step 10, the annular baffle 11, and the crystallization tank body 2 together enclose an overflow channel. The overflow pipe 3 is communicated with the overflow channel. In the present utility model, annular teeth 12 are provided at the upper end of the annular baffle 11. In the present invention, the supernatant slowly flows into the overflow channel between the teeth of the annular teeth 12 and then is sent out through the overflow pipe 13. Thus, the liquid with a high salt content or other impurities being carried out is effectively reduced.

[0031] In the upper part of the tank body 2 of the crystallization tank of the present utility model, a central sleeve 13 is provided. The stirring shaft 4 is arranged in the central sleeve 13. A diversion channel is formed between the inner wall of the central sleeve 13 and the outer wall of the stirring shaft 4. The lower end of the central sleeve 13 extends into the lower part of the tank body 2 of the crystallization tank. The water outlet pipe 8 is communicated with the middle part of the central sleeve 13. A flared opening 14 is provided at the lower end of the central sleeve 13. The central sleeve 13 is fixedly arranged on the inner wall of the tank body 2 of the crystallization tank through a connecting rod 15. The upper end of the central sleeve 13 is arranged on the upper end of the tank body 2 of the crystallization tank through a mounting bracket 16. In the present invention, the central sleeve effectively prevents the liquid in the upper part of the tank body of the crystallization tank from being agitated during the rotation of the stirring shaft, thereby providing favorable conditions for the precipitation and concentration of salts in the liquid.

[0032] The stirring member 6 of the present utility model includes a first stirring cross bar 61 and a second stirring cross bar 62 which are arranged at intervals on the outer wall of the lower end of the stirring shaft 4 from top to bottom. The length of the first stirring cross bar 61 is greater than that of the second stirring cross bar 62. Stirring inclined bars 63 are respectively arranged between the ends of the first stirring cross bar 61 and the second stirring cross bar 62. In order to further improve the stirring effect, stirring blades can also be respectively arranged on the stirring inclined bars 63 and the first stirring cross bar 61 or / and the second stirring cross bar 62 in the present invention.

[0033] A plurality of reinforcing rings 17 are arranged at intervals on the outer wall of the tank body 2 of the crystallization tank of the present utility model. The overall strength of the tank body 2 of the crystallization tank can be effectively increased through the reinforcing rings 17.

[0034] A slag discharge port 18 is provided at the lower part of the tank body 2 of the crystallization tank of the present utility model. A speed reducer 19 is arranged between the stirring motor 5 and the stirring shaft 4.

[0035] The above shows and describes the basic principles, main features and advantages of the present utility model. Those skilled in the art of this industry should understand that the present utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A crystallization tank for sewage treatment, comprising a base (1), on which a crystallization tank body (2) is arranged, characterized in that: An overflow pipe (3) is provided at the upper part of the crystallizer tank body (2), a stirring shaft (4) is provided inside the crystallizer tank body (2), the stirring shaft (4) is connected to a stirring motor (5) provided at the upper end of the crystallizer tank body (2), a stirring member (6) is provided at the lower end of the stirring shaft (4), a water inlet pipe (7) and a water outlet pipe (8) are provided at the upper part of the crystallizer tank body (2), an annular step (10) is provided inside the crystallizer tank body (2), an annular baffle (11) is provided inside the annular step (10), the annular baffle (11) and the crystallizer tank body (2) together form an overflow channel, and the overflow pipe (3) is connected to the overflow channel.

2. A crystallization tank for sewage treatment according to claim 1, characterized in that: An annular tooth (12) is provided at the upper end of the annular baffle (11).

3. A crystallization tank for sewage treatment according to claim 1 or 2, characterized in that: A central sleeve (13) is provided in the upper part of the crystallization tank body (2), the stirring shaft (4) is arranged in the central sleeve (13), and a guide channel is formed between the inner wall of the central sleeve (13) and the outer wall of the stirring shaft (4). The lower end of the central sleeve (13) extends into the lower part of the crystallization tank body (2), and the water outlet pipe (8) is connected to the middle part of the central sleeve (13).

4. A crystallization tank for sewage treatment according to claim 3, characterized in that: A trumpet-shaped opening (14) is provided at the lower end of the central sleeve (13).

5. A crystallization tank for sewage treatment according to claim 3, characterized in that: The central sleeve (13) is fixedly arranged on the inner wall of the crystallization tank body (2) via a connecting rod (15), and the upper end of the central sleeve (13) is arranged on the upper end of the crystallization tank body (2) via a mounting frame (16).

6. A crystallization tank for sewage treatment according to claim 1, characterized in that: The stirring member (6) comprises a first stirring cross bar (61) and a second stirring cross bar (62) which are arranged on the outer wall of the lower end of the stirring shaft (4) from top to bottom with a spacing therebetween, the length of the first stirring cross bar (61) being greater than the length of the second stirring cross bar (62), and stirring inclined bars (63) are respectively arranged between the end of the first stirring cross bar (61) and the end of the second stirring cross bar (62).

7. A crystallization tank for sewage treatment according to claim 1, characterized in that: A plurality of reinforcement rings (17) are arranged at intervals on the outer wall of the crystallization tank body (2).

8. A crystallization tank for sewage treatment according to claim 1, characterized in that: A slag discharge port (18) is provided at the lower part of the crystallization tank body (2).

9. A crystallization tank for sewage treatment according to claim 1, characterized in that: A reducer (19) is provided between the stirring motor (5) and the stirring shaft (4).

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