A desulfurization wastewater treatment system for a semi-coke boiler

Abstract

The utility model discloses a kind of desulfurization wastewater treatment systems for semi-coke boiler, boiler is provided economizer, air preheater and dust collector along flue gas flow direction, the smoke outlet of dust collector is connected with desulfurization absorption tower, and the smoke end of desulfurization absorption tower is connected with chimney;Desulfurization absorption tower is connected with sedimentation tank, the bottom of sedimentation tank is connected with filter press;The sludge outlet of filter press is connected with sludge tank, the liquid outlet of filter press is connected on waste liquid pipeline of desulfurization absorption tower;The liquid outlet of sedimentation tank is connected with clarifier, the supernatant of clarifier is connected with evaporator, the thick water of clarifier is connected with filter press;Condensate outlet of evaporator is connected with clean water tank, the concentrated liquid of evaporator is connected with thickener;Thickener is connected with atomizing spray gun;The controlled end of filter press, atomizing spray gun is connected with PLC controller.The utility model has the advantages of less equipment land occupation, low investment and operating cost, high degree of automation.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and more specifically to a desulfurization wastewater treatment system for semi-coke boilers. Background Technology

[0002] Semi-coke (also known as semi-coke or coke) has a blocky structure, with a particle size generally above 3mm, and a light black color. As a new type of carbon material, it is widely used in the production of calcium carbide, ferroalloys, ferrosilicon, silicon carbide, and other products due to its high fixed carbon content, high resistivity, high chemical activity, low ash content, low aluminum content, low sulfur content, and low phosphorus content. It has become an irreplaceable carbon material.

[0003] Combustion in semi-coke boilers produces large amounts of smoke, sulfur dioxide, and nitrogen oxides. Sulfur dioxide, a colorless gas with a strong, pungent odor, is a major air pollutant. Its emissions contribute to acid rain, posing a significant environmental hazard. Therefore, flue gas must be treated before release. Desulfurization wastewater is generated during the wet desulfurization process of boiler flue gas. The desulfurization unit periodically discharges a certain amount of wastewater during operation. This wastewater contains high concentrations of impurities, including suspended solids, inorganic salts, and heavy metal ions. Direct discharge of this wastewater easily causes environmental pollution, and the entire treatment process is energy-intensive. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a desulfurization wastewater treatment system for semi-coke boilers, so as to solve the problems in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows.

[0006] A desulfurization wastewater treatment system for a semi-coke boiler includes a boiler. An economizer, an air preheater, and a dust collector are installed along the flue gas flow direction of the boiler. The dust collector's outlet is connected to a desulfurization absorption tower, and the outlet of the desulfurization absorption tower is connected to a chimney. The wastewater outlet of the desulfurization absorption tower is connected to a sedimentation tank with added flocculant. The bottom of the sedimentation tank is connected to a filter press. The filter press's sludge outlet is connected to a sludge tank, and its liquid outlet is connected to the waste liquid pipeline of the desulfurization absorption tower. The sedimentation tank's liquid outlet is connected to a clarifier, the supernatant of which is connected to an evaporator, and the clarifier's concentrate is connected to the filter press. The evaporator's condensate outlet is connected to a clear water tank, and the evaporator's concentrate is connected to a thickener. The thickener's liquid outlet is connected to an atomizing spray gun installed in the dust collector. The dust collector is connected to high-temperature flue gas from the economizer for drying the atomized liquid. The filter press and the atomizing spray gun are connected to a PLC controller.

[0007] To further optimize the technical solution, an agitator for accelerating mixing is installed in the sedimentation tank. The agitator is located at the top of the sedimentation tank and is connected to a PLC controller.

[0008] To further optimize the technical solution, a sludge discharge pump is installed on the pipeline between the sedimentation tank and the filter press, and the sludge discharge pump is connected to a PLC controller.

[0009] To further optimize the technical solution, several atomizing spray guns are provided, and the atomizing spray guns are located on the top of the dust collector.

[0010] To further optimize the technical solution, the pipeline connecting the economizer and the dust collector is connected to the middle of the dust collector, a fan is installed on the pipeline, and the controlled end of the fan is connected to a PLC controller.

[0011] The technological advancements achieved by this utility model are as follows, due to the adoption of the above technical solutions.

[0012] This utility model provides a desulfurization wastewater treatment system for semi-coke boilers. The wastewater sprayed back into the dust collector absorbs heat from the economizer, achieving energy reuse. It also increases the humidity of the flue gas, improving the dust removal efficiency of subsequent dust collectors. Furthermore, pollutants in the concentrated wastewater can be filtered out by the dust collector. The water in the clear water tank can be used for industrial purposes, realizing the recycling of wastewater. This utility model has the advantages of small footprint, low investment and operating costs, and a high degree of automation. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the sedimentation tank section in this utility model; Figure 3 This is a structural block diagram of the connection between the present invention and the PLC controller; Among them: 1. Boiler, 2. Economizer, 3. Air preheater, 4. Dust collector, 5. Chimney, 6. Sedimentation tank, 61. Agitator, 7. Sludge pump, 8. Filter press, 9. Sludge tank, 10. Desulfurization absorption tower, 11. Clarifier, 12. Evaporator, 13. Clear water tank, 14. Thickener, 16. Atomizing spray gun. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] A desulfurization wastewater treatment system for semi-coke boilers, combined with Figures 1 to 3 As shown, it includes boiler 1, economizer 2, air preheater 3, dust collector 4, chimney 5, sedimentation tank 6, sludge pump 7, filter press 8, sludge tank 9, desulfurization absorption tower 10, clarifier 11, evaporator 12, clear water tank 13, thickener 14, and atomizing spray gun 16.

[0016] Boiler 1 is equipped with economizer 2, air preheater 3 and dust collector 4 along the flue gas flow direction. High-temperature flue gas recovers heat after passing through economizer 2 and air preheater 3. After the flue gas temperature is reduced to about 90°C, it enters dust collector 4 for dust removal. The flue gas outlet of dust collector 4 is connected to desulfurization absorption tower 10. Desulfurization absorption tower 10 removes acidic pollutants such as sulfur dioxide (SO2) and hydrogen chloride (HCl). The flue gas is discharged from the chimney 5 connected to the flue gas outlet of desulfurization absorption tower 10.

[0017] The wastewater outlet of the desulfurization absorption tower 10 is connected to a sedimentation tank 6. An agitator 61 for accelerated mixing is installed in the sedimentation tank, positioned at the top and connected to a PLC controller. Flocculant is added to the sedimentation tank 6, with the dosage controlled according to the actual amount of desulfurization wastewater. After addition, the agitator 61 is turned on to allow the flocculant to fully react with the desulfurization wastewater, resulting in sludge sedimentation. After a period of time, the agitator 61 is turned off, and the mixture is allowed to stand for a while. Stratification occurs in the sedimentation tank 6, with sludge accumulating at the bottom.

[0018] A sludge discharge pump 7 is installed on the pipeline between the sedimentation tank 6 and the filter press 8. The sludge discharge pump 7 transfers the sludge sediment from the sedimentation tank 6 to the filter press 8. The controlled ends of the sludge discharge pump 7 and the filter press 8 are connected to a PLC controller. The filter press 8 discharges the obtained sludge from the sludge outlet and transfers it to the connected sludge tank 9. The liquid outlet of the filter press 8 is connected to the waste liquid pipeline of the desulfurization absorption tower 10, where the obtained liquid is mixed with wastewater for further sedimentation and separation.

[0019] The outlet of sedimentation tank 6 is connected to clarifier 11, where clarification and conditioning take place. The supernatant from clarifier 11 is connected to evaporator 12, and the condensate outlet of evaporator 12 is connected to clear water tank 13, where the water can be used as industrial water. The concentrate from clarifier 11 is connected to filter press 8, and can be returned to sedimentation tank 6 for further sedimentation and stratification.

[0020] The remaining concentrated liquid from evaporator 12 is connected to thickener 14, and the clear liquid from thickener 14 is connected to clear water tank 13. The outlet of thickener 14 is connected to atomizing spray guns 16 installed in dust collector 4. Several atomizing spray guns 16 are installed, and the controlled end of each atomizing spray gun is connected to a PLC controller. The atomizing spray guns 16 are located at the top of dust collector 4. Dust collector 4 is connected to economizer 2. High-temperature flue gas from economizer 2 is introduced to dry the atomized liquid sprayed from the atomizing spray guns 16. The salts formed by evaporation are collected in dust collector 4 along with the flue gas. This utilizes the waste heat resources of low-temperature flue gas, resulting in low overall system energy consumption. The pipeline connecting economizer 2 and dust collector 4 is located in the middle of dust collector 4, and a fan is installed on the pipeline.

[0021] In this invention, all pipelines used for transporting liquids are equipped with a delivery pump and a flow meter. Both the delivery pump and the flow meter are connected to a power source, and the controlled end of the delivery pump is connected to a PLC controller.

[0022] In practical use, the high-temperature flue gas generated by boiler 1 recovers heat through economizer 2 and air preheater 3. After the flue gas temperature is reduced to about 90°C, it enters dust collector 4 for dust removal. Then, it is conveyed by induced draft fan to desulfurization absorption tower 10, where the flue gas temperature is further reduced to about 50°C before being discharged from chimney 5. The desulfurization wastewater discharged from desulfurization absorption tower 10 first enters sedimentation tank for solid sediment treatment. Flocculant causes the solid particles in the wastewater to fully coagulate and settle. The solid sludge is pumped into filter press, where the dewatering rate of the sludge is further improved. The resulting sludge is transported to sludge pool, and the liquid produced by filter pressing is returned to sedimentation tank through pipeline to participate in the sedimentation process again. The upper layer of liquid in sedimentation tank enters evaporator for concentration. The condensate produced in evaporator is stored in clear water pool, and the remaining concentrate enters thickener for further concentration. The clear liquid in the thickener is connected to clear water pool 13, and the water in the clear water pool can be recycled as industrial water. The concentrate is dried by the heat of the flue gas in the dust collector through the atomizing spray gun, and the resulting dust is captured by the dust collector and discharged through the dust collector.

Claims

1. A desulfurization wastewater treatment system for semi-coke boilers, characterized in that: The boiler (1) includes an economizer (2), an air preheater (3), and a dust collector (4) arranged along the flue gas flow direction. The flue gas outlet of the dust collector (4) is connected to a desulfurization absorption tower (10), and the flue gas outlet of the desulfurization absorption tower (10) is connected to a chimney (5). The wastewater outlet of the desulfurization absorption tower (10) is connected to a sedimentation tank (6) with added flocculant. The bottom of the sedimentation tank (6) is connected to a filter press (8). The sludge outlet of the filter press (8) is connected to a sludge tank (9), and the liquid outlet of the filter press (8) is connected to the waste liquid pipeline of the desulfurization absorption tower (10). The outlet of (6) is connected to the clarifier (11), the supernatant of the clarifier (11) is connected to the evaporator (12), and the concentrate of the clarifier (11) is connected to the filter press (8); the condensate outlet of the evaporator (12) is connected to the clear water tank (13), and the concentrate of the evaporator (12) is connected to the thickener (14); the outlet of the thickener (14) is connected to an atomizing spray gun (16) installed in the dust collector (4), and the dust collector (4) is connected to the high-temperature flue gas in the economizer (2) for drying the atomized liquid; the controlled end of the filter press and the atomizing spray gun is connected to the PLC controller.

2. The desulfurization wastewater treatment system for semi-coke boilers according to claim 1, characterized in that: The sedimentation tank is equipped with an agitator (61) to accelerate mixing. The agitator (61) is located at the top of the sedimentation tank (6) and is connected to a PLC controller.

3. The desulfurization wastewater treatment system for semi-coke boilers according to claim 1, characterized in that: A sludge pump (7) is installed on the pipeline between the sedimentation tank (6) and the filter press (8), and the sludge pump is connected to a PLC controller.

4. The desulfurization wastewater treatment system for semi-coke boilers according to claim 1, characterized in that: Several atomizing spray guns (16) are provided, and the atomizing spray guns (16) are located on top of the dust collector (4).

5. The desulfurization wastewater treatment system for semi-coke boilers according to claim 4, characterized in that: The pipeline connecting the economizer (2) and the dust collector (4) is connected in the middle of the dust collector (4). A fan is installed on the pipeline, and the controlled end of the fan is connected to a PLC controller.

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