Desulfurization tail gas treatment system

Abstract

The utility model discloses a desulfurization tail gas treatment system which is characterized by comprising a desulfurization tower, an acid washing tower, an alkaline washing tower, a water washing tower and a dry quenching furnace. The device and the method have the advantages that firstly, elemental sulfur and H2S components carried in the desulfurized tail gas are removed through the alkaline washing tower, then ammonia in the desulfurized tail gas is removed through the acid washing tower, finally, acid mist in the desulfurized tail gas is removed through the water washing tower, and the desulfurized tail gas is conveyed to the dry quenching furnace for dry quenching through the fan for incineration treatment, so that harmful substances in the flue gas are treated through high-temperature incineration. Meanwhile, by arranging the plate heat exchanger, the temperature of the ammonia distillation wastewater entering the water washing tower is reduced, pollutants carried in the flue gas can be more easily absorbed and removed in the water washing tower, the temperature of the flue gas out of the water washing tower can be reduced, and the saturated water content in the tail gas is further reduced due to the low temperature; the denudation effect of refractory bricks used for the furnace body of the dry quenching furnace is relieved, and the service life of the dry quenching furnace is prolonged.

Description

Technical field:

[0001] The utility model relates to the field of tail gas treatment, in particular to a desulfurized tail gas treatment system. Background technology:

[0002] Desulfurized flue gas is a common emission from various industries, including coal-fired power generation, steel, chemical, and petroleum refining. It contains pollutants such as sulfur dioxide and particulate matter, which are harmful to the environment. Therefore, desulfurized flue gas treatment is necessary to protect the environment and human health.

[0003] Limestone-gypsum wet flue gas desulfurization technology is the most widely used and mature flue gas desulfurization process. Its exhaust temperature is relatively high, resulting in a high moisture content in the exhaust gas. When the desulfurized exhaust gas is sent to the dry quenching furnace for incineration, the moisture carried in the exhaust gas will have a very adverse effect on the service life of the refractory bricks of the dry quenching furnace. Utility model content:

[0004] In order to solve the above problems, the purpose of the present invention is to provide a desulfurization tail gas processing system.

[0005] The utility model is implemented by the following technical solutions:

[0006] A desulfurization tail gas treatment system includes a desulfurization tower, an acid washing tower, an alkali washing tower, a water washing tower and a dry quenching furnace;

[0007] The flue gas outlet of the desulfurization tower is connected to the flue gas inlet of the lower part of the alkali washing tower through a pipeline, the flue gas outlet at the top of the alkali washing tower is connected to the flue gas inlet of the lower part of the acid washing tower through a pipeline, the flue gas outlet at the top of the acid washing tower is connected to the flue gas inlet of the lower part of the water washing tower through a pipeline, the flue gas outlet at the top of the water washing tower is connected to the inlet of the fan through a pipeline, and the outlet of the fan is connected to the flue gas inlet of the dry quenching furnace through a pipeline;

[0008] The liquid outlet of the dilute alkali liquid storage tank is connected to the spray liquid inlet at the upper end of the alkali washing tower through a pipeline, and the liquid outlet of the desulfurization liquid storage tank is connected to the spray liquid inlet at the lower end of the alkali washing tower through a pipeline;

[0009] The liquid outlet of the ammonium sulfate solution storage tank is connected to the spray liquid inlet of the pickling tower through a pipeline;

[0010] The liquid outlet of the washing water storage tank is connected to the spray liquid inlet of the water washing tower through a pipeline;

[0011] A temperature sensor is provided at the flue gas outlet of the water scrubber, and a water flow regulating valve is provided on the pipeline connecting the washing water storage tank and the water scrubber;

[0012] The signal output end of the temperature sensor is signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the water flow regulating valve.

[0013] Furthermore, the ammonia evaporation wastewater outlet of the ammonia evaporation tower is connected to the liquid inlet of the dilute alkali solution storage tank through a pipeline, the alkali solution outlet of the ammonia evaporation tower is connected to the pipeline connecting the ammonia evaporation tower and the dilute alkali solution storage tank through an alkali solution pipeline, a pH sensor is provided in the dilute alkali solution storage tank, and an alkali solution flow regulating valve is provided on the alkali solution pipeline;

[0014] The signal output end of the pH sensor is signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the alkali solution flow regulating valve.

[0015] Furthermore, the ammonia evaporation wastewater outlet of the ammonia evaporation tower is connected to the liquid inlet of the washing water storage tank through a pipeline.

[0016] Furthermore, the ammonia evaporation wastewater outlet of the ammonia evaporation tower is connected to the heat medium inlet of the plate heat exchanger through a pipeline, and the heat medium outlet of the plate heat exchanger is connected to the liquid inlet of the washing water storage tank through a pipeline.

[0017] Advantages of this utility model:

[0018] The desulfurized tail gas first passes through an alkaline washing tower to remove elemental sulfur and H2S components carried in the tail gas, then passes through an acid washing tower to remove ammonia, and finally passes through a water washing tower to remove acid mist. It is then sent to a dry quenching furnace for incineration through a fan to treat harmful substances in the flue gas through high-temperature incineration.

[0019] At the same time, by setting up a plate heat exchanger, the temperature of the ammonia wastewater entering the water scrubber can be reduced, which can make the pollutants carried in the flue gas more easily absorbed and removed in the water scrubber. The flue gas temperature out of the water scrubber can also be reduced. The low temperature further reduces the saturated water content in the exhaust gas, slows down the effect of erosion of refractory bricks used in the dry quenching furnace body, and extends the service life of the dry quenching furnace. Description of the drawings:

[0020] Figure 1 This is a schematic diagram of system connection of the utility model;

[0021] Figure 2 This is a control principle diagram of the utility model;

[0022] In the figure: desulfurization tower 1, alkali washing tower 2, acid washing tower 3, water washing tower 4, fan 5, dry quenching furnace 6, ammonia distillation tower 7, dilute alkali solution storage tank 8, desulfurization liquid storage tank 9, ammonium sulfate solution storage tank 10, plate heat exchanger 11, washing water storage tank 12, temperature sensor 13, pH sensor 14, controller 15, water flow regulating valve 16, alkali solution flow regulating valve 17. Specific implementation method:

[0023] like Figure 1 、 Figure 2 The desulfurization tail gas treatment system shown includes a desulfurization tower 1, an acid washing tower 3, an alkaline washing tower 2, a water washing tower 4 and a dry quenching furnace 6;

[0024] The flue gas outlet of the desulfurization tower 1 is connected to the flue gas inlet of the lower part of the alkali washing tower 2 through a pipeline, the flue gas outlet of the top of the alkali washing tower 2 is connected to the flue gas inlet of the lower part of the acid washing tower 3 through a pipeline, the flue gas outlet of the top of the acid washing tower 3 is connected to the flue gas inlet of the lower part of the water washing tower 4 through a pipeline, the flue gas outlet of the top of the water washing tower 4 is connected to the inlet of the fan 5 through a pipeline, and the outlet of the fan 5 is connected to the flue gas inlet of the dry quenching furnace 6 through a pipeline;

[0025] The ammonia evaporation wastewater outlet of the ammonia evaporation tower 7 is connected to the liquid inlet of the dilute alkali solution storage tank 8 through a pipeline, the alkali solution outlet of the ammonia evaporation tower 7 is connected to the pipeline connecting the ammonia evaporation tower 7 and the dilute alkali solution storage tank 8 through an alkali solution pipeline, the liquid outlet of the dilute alkali solution storage tank 8 is connected to the spray liquid inlet at the upper end of the alkali washing tower 2 through a pipeline, and the liquid outlet of the desulfurization liquid storage tank 9 is connected to the spray liquid inlet at the lower end of the alkali washing tower 2 through a pipeline;

[0026] The liquid outlet of the ammonium sulfate solution storage tank 10 is connected to the spray liquid inlet of the pickling tower 3 through a pipeline;

[0027] The ammonia evaporation wastewater outlet of the ammonia evaporation tower 7 is connected to the heat medium inlet of the plate heat exchanger 11 through a pipeline. The heat medium outlet of the plate heat exchanger 11 is connected to the liquid inlet of the washing water storage tank 12 through a pipeline. The liquid outlet of the washing water storage tank 12 is connected to the spray liquid inlet of the water washing tower 4 through a pipeline.

[0028] A temperature sensor 13 is provided at the flue gas outlet of the water washing tower 4, and a water flow regulating valve 16 is provided on the pipeline connecting the washing water storage tank 12 and the water washing tower 4; a pH sensor 14 is provided in the dilute alkali solution storage tank 8, and an alkali solution flow regulating valve 17 is provided on the alkali solution pipeline.

[0029] The signal output ends of the temperature sensor 13 and the pH sensor 14 are both signal-connected to the signal input end of the controller 15 , and the signal output end of the controller 15 is signal-connected to the signal input ends of the water flow regulating valve 16 and the alkali solution flow regulating valve 17 .

[0030] Job Description:

[0031] The desulfurized tail gas from desulfurization tower 1 first enters the lower section of alkali scrubber 2, where it is scrubbed in two sections, upper and lower. The lower section is sprayed with desulfurization liquid to remove elemental sulfur from the tail gas. The ammonia evaporation caustic soda from ammonia evaporation tower 7 is diluted with ammonia evaporation wastewater from ammonia evaporation tower 7 and then enters the dilute caustic soda storage tank 8, where it is sprayed on the upper section of alkali scrubber 2 to remove H2S from the tail gas.

[0032] The tail gas discharged from the top of the alkali scrubber 2 enters the lower part of the acid scrubber 3, where it comes into countercurrent contact with the ammonium sulfate solution sprayed down from each section. After removing ammonia, it enters the water scrubber 4. In this embodiment, the acid scrubber 3 automatically adjusts the liquid level to send excess ammonium sulfate solution to the mother liquor storage tank of the ammonium sulfate section to produce ammonium sulfate.

[0033] The exhaust gas from the acid scrubber 3 enters the water scrubber 4, where it comes into countercurrent contact with the ammonia evaporation wastewater from the ammonia evaporation tower 7. The acid mist is then removed and then transported via a blower 5 to the coke dry quenching furnace 6 for incineration, thereby removing harmful substances from the flue gas through high-temperature incineration. Similarly, in this embodiment, the water scrubber 4 automatically adjusts the liquid level to transport the ammonia evaporation wastewater to the phenol-cyanide wastewater treatment section.

[0034] In this embodiment, the plate heat exchanger 11 is provided to lower the temperature of the ammonia wastewater entering the water scrubber 4, making it easier for pollutants carried in the flue gas to be absorbed and removed in the water scrubber 4. The flue gas temperature exiting the water scrubber 4 is also lowered. The low temperature further reduces the saturated water content in the exhaust gas, thereby mitigating the erosion of the refractory bricks used in the dry quenching furnace 6. The temperature sensor 13 is provided to detect the flue gas temperature exiting the water scrubber 4. By adjusting the opening of the water flow control valve 16, the flue gas temperature exiting the water scrubber 4 is maintained at 19-21°C.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A desulfurization tail gas treatment system, characterized in that: Including desulfurization tower, acid washing tower, alkali washing tower, water washing tower and dry quenching furnace; The flue gas outlet of the desulfurization tower is connected to the flue gas inlet of the lower part of the alkali washing tower through a pipeline, the flue gas outlet at the top of the alkali washing tower is connected to the flue gas inlet of the lower part of the acid washing tower through a pipeline, the flue gas outlet at the top of the acid washing tower is connected to the flue gas inlet of the lower part of the water washing tower through a pipeline, the flue gas outlet at the top of the water washing tower is connected to the inlet of the fan through a pipeline, and the outlet of the fan is connected to the flue gas inlet of the dry quenching furnace through a pipeline; The liquid outlet of the dilute alkali liquid storage tank is connected to the spray liquid inlet at the upper end of the alkali washing tower through a pipeline, and the liquid outlet of the desulfurization liquid storage tank is connected to the spray liquid inlet at the lower end of the alkali washing tower through a pipeline; The liquid outlet of the ammonium sulfate solution storage tank is connected to the spray liquid inlet of the pickling tower through a pipeline; The liquid outlet of the washing water storage tank is connected to the spray liquid inlet of the water washing tower through a pipeline; A temperature sensor is provided at the flue gas outlet of the water scrubber, and a water flow regulating valve is provided on the pipeline connecting the washing water storage tank and the water scrubber; The signal output end of the temperature sensor is signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the water flow regulating valve.

2. A desulfurized tail gas processing system according to claim 1, characterized in that: The ammonia evaporation wastewater outlet of the ammonia evaporation tower is connected to the liquid inlet of the dilute alkali solution storage tank through a pipeline, and the alkali solution outlet of the ammonia evaporation tower is connected to the pipeline connecting the ammonia evaporation tower and the dilute alkali solution storage tank through an alkali solution pipeline. A pH sensor is provided in the dilute alkali solution storage tank, and an alkali solution flow regulating valve is provided on the alkali solution pipeline; The signal output end of the pH sensor is signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the alkali solution flow regulating valve.

3. A desulfurized tail gas processing system according to claim 1, characterized in that: The ammonia evaporation wastewater outlet of the ammonia evaporation tower is connected to the liquid inlet of the washing water storage tank through a pipeline.

4. A desulfurized tail gas processing system according to claim 3, characterized in that: The ammonia evaporation wastewater outlet of the ammonia evaporation tower is connected to the heat medium inlet of the plate heat exchanger through a pipeline, and the heat medium outlet of the plate heat exchanger is connected to the liquid inlet of the washing water storage tank through a pipeline.

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