High-efficiency clarification device for desulfurization wastewater and application method of high-efficiency clarification device

Abstract

The invention provides an efficient desulfurization wastewater clarification device which comprises a clarification tank main body, and an inner cavity of the clarification tank main body is sequentially provided with an upper heat exchanger, a heat exchange pipe and a lower heat exchanger from top to bottom; the bottom of the heat exchange pipe is connected with a pipeline bracket, and clarification tank filler is arranged at the top of the heat exchange pipe; wherein the other end of the pipeline bracket is connected with the bottom of a sedimentation tank in the clarification tank main body; a sludge outlet is formed in the bottom of the sedimentation tank; the device can automatically clean and operate, is high in automation degree, and can specifically and efficiently precipitate desulfurization wastewater compared with a traditional precipitation tank; strong brine is used as a heat exchange medium for heat exchange, so that the temperature of the strong brine is increased, heat needed by temperature rise of the rear-end evaporation section is reduced, and the energy-saving effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of water treatment, and particularly to a high-efficiency clarification device for desulfurization wastewater and an application method thereof. Background Art

[0002] Desulfurization wastewater comes from the flue gas desulfurization system of thermal power plants, and is characterized by high water temperature, high suspended solid concentration, high COD, and acidic pH value. At present, the power industries in developed foreign countries are in a period of transformation, and the zero-discharge technology of desulfurization wastewater from coal-fired power plants has stagnated. The traditional desulfurization wastewater treatment process is neutralization and precipitation treatment, and then after steps such as flocculation, clarification, and concentration, the clear water is recycled, and the wastewater is transported out for disposal after sludge dewatering. With the continuous improvement of China's environmental protection requirements, the demand for desulfurization wastewater disposal in coal-fired power plants has also been continuously increasing.

[0003] Pretreatment is the first step in treating desulfurization wastewater. In this process, suspended solids, soluble pollutants, and heavy metal ions in the wastewater can be removed to prevent them from interfering with subsequent processes. The common pretreatment technology is the precipitation method, which uses chemical dosing flocculation combined with physical precipitation to remove suspended substances in the wastewater.

[0004] Although the existing sedimentation tanks can achieve the purpose of high-efficiency precipitation by adding inclined plates, part of the added coagulants and flocculants will dissolve in the water body, thus affecting the product quality of the subsequent zero-discharge process, resulting in low system recycling rate and poor economy; at the same time, desulfurization wastewater itself has a certain viscosity, low thermal conductivity, and poor heat transfer ability. The inlet water temperature of the desulfurization slurry in the sedimentation tank is generally above 50°C. During the precipitation process, the water temperature at the upper and lower parts drops rapidly, and the water temperature in the middle is higher. Due to the internal temperature difference in the sedimentation tank, a convection phenomenon is continuously formed, the hotter part rises, and the colder part drops, circulating and mixing with each other, resulting in high turbidity of the water produced by the sedimentation tank and poor operation effect; in addition, due to the characteristics of high suspended solids in desulfurization wastewater, the added inclined plates are easily contaminated and need to be drained and manually cleaned frequently, resulting in difficulty in long-term stable operation.

[0005] The purpose of this solution is to solve the problems of low system recycling rate caused by adding coagulants and flocculants during the operation of the desulfurization wastewater clarification pretreatment equipment, poor operation effect caused by the convection phenomenon formed by the internal temperature difference of the desulfurization slurry in the sedimentation tank, and easy contamination of the inclined plates caused by a large amount of mud. Summary of the Invention

[0006] To solve the above problems, the present invention discloses a high-efficiency clarification device for desulfurization wastewater and an application method thereof, which can perform real-time temperature control on the desulfurization wastewater in the clarification tank; at the same time, the design of the heat exchange tubes can automatically clean the packing in the clarification tank through the water hammer phenomenon, reduce the convection phenomenon caused by the internal temperature difference, and reduce the maintenance frequency, thereby achieving the purpose of high-efficiency precipitation.

[0007] An efficient clarification device for desulfurized wastewater, comprising a main body of a clarification tank. Inside the main body of the clarification tank, there are successively arranged an upper heat exchanger, heat exchange tubes, and a lower heat exchanger from top to bottom. The bottom of the heat exchange tubes is connected to a pipeline support, and the top is provided with clarification tank packing. One end of the pipeline support is connected to the bottom of a sedimentation tank inside the main body of the clarification tank. A sludge discharge port is provided at the bottom of the sedimentation tank. One end of the upper heat exchanger is connected to an upper heat exchanger water inlet, and the other end is connected to an upper heat exchanger water outlet. One end of the heat exchange tubes is connected to a middle heat exchange tube water inlet, and the other end is connected to a middle heat exchange tube water outlet. One end of the lower heat exchanger is connected to a lower heat exchange tube water inlet, and the other end is connected to a lower heat exchange tube water outlet. At the front end of the main body of the clarification tank, there are successively arranged a desulfurized wastewater outlet and a desulfurized wastewater inlet.

[0008] Further, the middle heat exchange tube water inlet and the middle heat exchange tube water outlet are respectively connected to the heat exchange tubes through flexible connecting tubes.

[0009] Further, the flexible connecting tube is a steel wire braided tube or a plastic hose.

[0010] Further, a shock absorption device is installed between the pipeline support and the heat exchange tubes to reduce the influence of the vibration of the heat exchange tubes on the pipeline support, and it can be a spring, a pneumatic buffer or other shock absorption devices.

[0011] Further, the shock absorption device is a spring or a pneumatic buffer.

[0012] Further, the clarification tank packing is fixed on the heat exchange tubes by bundling, welding or filling and pressing.

[0013] Further, the upper heat exchanger, the heat exchange tubes and the lower heat exchanger operate independently, and the heat exchange media of the three do not flow through each other.

[0014] Further, the medium in the heat exchanger adopts concentrated brine, industrial wastewater, tap water or other low-temperature media in the desulfurized wastewater treatment process;

[0015] Further, the packing material of the clarification tank packing is a PP inclined plate, a PVC inclined plate or a steel plate.

[0016] Further, temperature sensors are arranged on the upper heat exchanger, the heat exchange tubes and the lower heat exchanger.

[0017] An application method of an efficient clarification device for desulfurized wastewater, comprising the following steps:

[0018] Step 1: The desulfurized wastewater enters the clarification tank from the desulfurized wastewater inlet, is settled and separated by the clarification tank packing, the clear water is discharged from the desulfurized wastewater outlet and sent into the ultrafiltration device, and the sludge is discharged from the sludge discharge port into the collection system.

[0019] Step 2: The concentrated brine serves as the heat exchange medium and enters the upper heat exchanger, the middle heat exchange tubes, and the lower heat exchange tubes through the upper heat exchanger water inlet, the middle heat exchange tube water inlet, and the lower heat exchange tube water inlet for heat exchange. The flow rate is dynamically adjusted according to the data of the temperature sensor.

[0020] Furthermore, when the packed clarifier is blocked, the flow rate of the middle heat exchange tube water inlet is increased, and the water hammer effect is utilized to vibrate the clarifier packing to achieve self-cleaning.

[0021] Furthermore, the flow rate of the heat exchange medium is calculated by the following formula:

[0022]

[0023] In the formula, G is the flow rate of the concentrated brine in each heat exchange device, kg / h;

[0024] G1 is the flow rate of the desulfurized wastewater in each heat exchange device area, kg / h;

[0025] c1 is the specific heat capacity of the desulfurized wastewater, kJ / (kg·°C);

[0026] c is the specific heat capacity of the concentrated brine, kJ / (kg·°C);

[0027] T1 and T2 are the temperature changes of the desulfurized wastewater before and after passing through each heat exchange area, kJ / (kg·°C);

[0028] t1 and t2 are the temperature changes of the concentrated brine before and after passing through each heat exchange area, kJ / (kg·°C);

[0029] The flow rate of the heat exchange medium (concentrated brine) in the heat exchanger of each area is automatically adjusted according to the temperature feedback of the temperature sensors in each area in the above formula, so as to achieve the purpose of quickly and uniformly cooling the desulfurized wastewater in the clarification device, and reducing the problems of liquid convection and suspension substances unable to settle caused by the internal temperature difference.

[0030] Advantages of the present invention:

[0031] 1. The present invention can be automatically cleaned and operated, with a high degree of automation. Compared with traditional sedimentation tanks, it can efficiently precipitate desulfurized wastewater in a targeted manner;

[0032] 2. The present invention can use the concentrated brine as the heat exchange medium for heat exchange, thereby increasing the temperature of the concentrated brine and reducing the heat required for the subsequent evaporation section to heat up, having the effect of energy conservation;

[0033] 3. The present invention can complete precipitation without adding flocculants and coagulants, which can improve the quality of subsequent resource products;

[0034] 4. The equipment of the present invention has a high degree of integration and a small floor area. Description of the Drawings

[0035] Figure 1 Front view of the high - efficiency clarifying device for desulfurized wastewater;

[0036] Figure 2 、 Figure 1 Sectional view along AA in

[0037] Figure 3 、 Figure 1 Sectional view along BB in

[0038] Figure 4 Process flow chart of the high - efficiency clarification system for desulfurized wastewater.

[0039] List of reference numerals:

[0040] Among them, 1 is the inlet of the upper heat exchanger, 2 is the outlet of the upper heat exchanger, 3 is the inlet of the middle heat exchange tube, 4 is the outlet of the middle heat exchange tube, 5 is the inlet of the lower heat exchange tube, 6 is the outlet of the lower heat exchange tube, 7 is the outlet of desulfurized wastewater, 8 is the inlet of desulfurized wastewater, 9 is the sludge discharge port, 10 is the clarifier filler, 11 is the flexible connecting pipe, 12 is the heat exchange tube, 13 is the upper heat exchanger, 14 is the lower heat exchanger, 15 is the temperature sensor, 16 is the pipeline support, and 161 is the shock absorption device. Detailed implementation manners

[0041] The following further clarifies the present invention in conjunction with the drawings and specific implementation manners. It should be understood that the following specific implementation manners are only used to illustrate the present invention and not to limit the scope of the present invention. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the words "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0042] As Figures 1-3 shown, a high - efficiency clarifying device for desulfurized wastewater in this embodiment includes a clarifier main body. An upper heat exchanger 13, a heat exchange tube 12 and a lower heat exchanger 14 are successively arranged in the inner cavity of the clarifier main body from top to bottom; the bottom of the heat exchange tube 12 is connected to a pipeline support 16 and the top is provided with a clarifier filler 10; the other end of the pipeline support 16 is connected to the bottom of the sedimentation tank in the clarifier main body; a sludge discharge port 9 is provided at the bottom of the sedimentation tank; one end of the upper heat exchanger 13 is connected to the inlet of the upper heat exchanger 1 and the other end is connected to the outlet of the upper heat exchanger 2; one end of the heat exchange tube 12 is connected to the inlet of the middle heat exchange tube 3 and the other end is connected to the outlet of the middle heat exchange tube 4; one end of the lower heat exchanger 14 is connected to the inlet of the lower heat exchange tube 5 and the other end is connected to the outlet of the lower heat exchange tube 6; the front end of the clarifier main body is successively provided with an outlet of desulfurized wastewater 7 and an inlet of desulfurized wastewater 8.

[0043] Among them, the inlet 3 of the middle heat exchange tube and the outlet 4 of the middle heat exchange tube are respectively connected to the heat exchange tube 12 through flexible connecting tubes 11; the flexible connecting tubes 11 are steel wire braided tubes.

[0044] A shock absorption device 161 is installed between the pipeline support 16 and the heat exchange tube 12; the shock absorption device 161 is a pneumatic buffer.

[0045] The clarifier filler 10 is fixed to the heat exchange tube 12 by bundling.

[0046] The upper heat exchanger 13, the heat exchange tube 12 and the lower heat exchanger 14 operate independently, and the heat exchange media of the three do not flow to each other; the medium in the heat exchanger is concentrated brine in the desulfurized wastewater treatment process.

[0047] Among them, temperature sensors 15 are arranged on the upper heat exchanger 13, the heat exchange tube 12 and the lower heat exchanger 14.

[0048] The process flow chart of the equipment is shown in Figure 4 , the desulfurized wastewater enters the high-efficiency clarifier through the desulfurized wastewater inlet 8. Under the combined action of gravity and the clarifier filler 10, the suspended solids in the water gradually settle. The settled muddy water is discharged into the collection system through the sludge discharge port 9, and the clear water flows out from the desulfurized wastewater outlet 7 to the ultrafiltration device. After being further purified by the ultrafiltration device, it enters the concentration device for concentration. The concentrated clear water is recycled, and the concentrated brine enters the upper heat exchanger 13, the heat exchange tube 12 and the lower heat exchanger 14 through the upper heat exchanger inlet 1, the middle heat exchange tube inlet 3 and the lower heat exchange tube inlet 5, and finally flows out from the upper heat exchanger outlet 2, the middle heat exchange tube outlet 4 and the lower heat exchange tube outlet 6 respectively and enters the evaporation device.

[0049] The flow rate is dynamically adjusted according to the data of the temperature sensor 15. The flow rate of the heat exchange medium is calculated by the following formula:

[0050]

[0051] In the formula, G is the flow rate of concentrated brine in each heat exchange device, kg / h;

[0052] G1 is the flow rate of desulfurized wastewater in each heat exchange device area, kg / h;

[0053] c1 is the specific heat capacity of desulfurized wastewater, kJ / (kg·℃);

[0054] c is the specific heat capacity of concentrated brine, kJ / (kg·℃);

[0055] T1 and T2 are the temperature changes before and after the desulfurized wastewater passes through each heat exchange area, kJ / (kg·℃);

[0056] t1, t2 - the temperature changes before and after the concentrated brine passes through each heat exchange area, kJ / (kg·℃);

[0057] The heat transfer medium flow rate in the heat exchanger of each area is automatically adjusted according to the temperature feedback from the temperature sensors in each area in the above formula.

[0058] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. An efficient clarification device for desulfurized wastewater, characterized in that, It includes a clarifier main body, and an upper heat exchanger (13), heat exchange tubes (12) and a lower heat exchanger (14) are successively arranged in the inner cavity of the clarifier main body from top to bottom; a pipe support (16) is connected to the bottom of the heat exchange tubes (12), and a clarifier filler (10) is arranged at the top; the other end of the pipe support (16) is connected to the bottom of the sedimentation tank in the clarifier main body; a sludge discharge port (9) is arranged at the bottom of the sedimentation tank; one end of the upper heat exchanger (13) is connected to the upper heat exchanger water inlet (1), and the other end is connected to the upper heat exchanger water outlet (2); one end of the heat exchange tubes (12) is connected to the middle heat exchange tube water inlet (3), and the other end is connected to the middle heat exchange tube water outlet (4); one end of the lower heat exchanger (14) is connected to the lower heat exchange tube water inlet (5), and the other end is connected to the lower heat exchange tube water outlet (6); a desulfurized wastewater outlet (7) and a desulfurized wastewater inlet (8) are successively arranged at the front end of the clarifier main body.

2. The highly efficient clarification device for desulfurized wastewater according to claim 1, characterized in that, The middle heat exchange tube water inlet (3) and the middle heat exchange tube water outlet (4) are respectively connected to the heat exchange tubes (12) through flexible connecting tubes (11).

3. The highly efficient clarification device for desulfurized wastewater according to claim 2, characterized in that, The flexible connecting tube (11) is a steel wire braided tube or a plastic hose.

4. The highly efficient clarification device for desulfurized wastewater according to claim 1, wherein, A shock absorption device (161) is installed between the pipe support (16) and the heat exchange tubes (12).

5. An efficient clarification device for desulfurized wastewater according to claim 4, characterized in that, The shock absorption device (161) is a spring or a pneumatic buffer.

6. The highly efficient clarification device for desulfurized wastewater according to claim 1, characterized in that, The clarifier filler (10) is fixed on the heat exchange tubes (12) by bundling, welding or filling.

7. The highly efficient clarification device for desulfurized wastewater according to claim 1, wherein, The upper heat exchanger (13), the heat exchange tubes (12) and the lower heat exchanger (14) operate independently, and the heat exchange media of the three do not flow through each other.

8. The highly efficient clarification device for desulfurized wastewater according to claim 7, characterized in that The medium in the heat exchanger adopts concentrated brine, industrial wastewater, tap water or other low-temperature media in the desulfurized wastewater treatment process; temperature sensors (15) are arranged on the upper heat exchanger (13), the heat exchange tubes (12) and the lower heat exchanger (14).

9. A method for applying an efficient clarification device for desulfurized wastewater, characterized in that, It includes the following steps: Step 1: Desulfurized wastewater enters the clarifier from the desulfurized wastewater inlet (8), is settled and separated by the clarifier filler (10), the clear water is discharged from the desulfurized wastewater outlet (7) and sent into the ultrafiltration device, and the sludge is discharged from the sludge discharge port (9) into the collection system. Step 2: Concentrated brine is used as the heat exchange medium and enters the upper heat exchanger (13), the heat exchange tubes (12) and the lower heat exchanger (14) through the upper heat exchanger water inlet (1), the middle heat exchange tube water inlet (3) and the lower heat exchange tube water inlet (5) for heat exchange, and the flow rate is dynamically adjusted according to the data of the temperature sensor (15).

10. The application method of a high-efficiency clarification device for desulfurized wastewater according to claim 9, characterized in that, When the filler clarifier (10) is blocked, increase the flow rate of the middle heat exchange tube water inlet (3), and use the water hammer effect to vibrate the clarifier filler (10) to achieve self-cleaning; the flow rate of the heat exchange medium is calculated by the following formula: In the formula, G——the flow rate of concentrated brine in each heat exchange device, kg / h; G1——the flow rate of desulfurized wastewater in each heat exchange device area, kg / h; c1——the specific heat capacity of desulfurized wastewater, kJ / (kg·℃); c——the specific heat capacity of concentrated brine, kJ / (kg·℃); T1, T2——the temperature change before and after the desulfurized wastewater passes through each heat exchange area, kJ / (kg·℃); t1, t2 - the temperature changes before and after the concentrated brine passes through each heat exchange area, kJ / (kg·℃); The flow rate of the heat exchange medium in the heat exchanger of each area is automatically adjusted according to the temperature feedback by the temperature sensors in each area in the above formula.

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