Desulfurized fly ash resource utilization device

Abstract

The utility model relates to the technical field of environmental protection, in particular to a desulfurization ash resource utilization device which comprises a wet desulfurization tower, and the wet desulfurization tower is sequentially provided with a wet electric dust remover, a demister, a spraying layer and a liquid storage tank from top to bottom; the number of the spraying layers is not less than two; the liquid storage tank is sequentially communicated with the oxidation aeration tank and the desulfurizing agent regeneration tank, and the desulfurizing agent regeneration tank is further communicated with the spraying layer; a feed port of the desulfurizing agent regeneration tank is communicated with a liquid discharge port of the desulfurized ash slurry separation device, the desulfurized ash slurry separation device is communicated with the desulfurized ash storage bin, and desulfurized ash comes from a dry desulfurization process. The flue gas in the wet desulfurization tower is continuously desulfurized by using the unreacted desulfurizer in the desulfurized ash slurry, so that the utilization rate of the desulfurized ash is improved, and meanwhile, the desulfurization efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection, in particular to a desulfurization ash resource utilization device. Background Art

[0002] The fuel gas used in hot blast furnaces, steel rolling heating furnaces, and gas-fired boilers in power plants in the steel industry generally comes from the three major coal gases generated during the steel industry's production processes: blast furnace gas, coke oven gas, and converter gas. Consequently, the SO2 content in the flue gas from these hot blast furnaces, steel rolling heating furnaces, and gas-fired boilers in power plants is relatively low, and dry desulfurization is the primary desulfurization process. Dry desulfurization primarily utilizes solid absorbents (such as limestone, dolomite, or slaked lime) to remove SO2 from flue gas. Typically, fine powdered solid absorbents are sprayed into the furnace or exposed to the flue gas in a reaction tower, generating desulfurization ash containing calcium sulfate, magnesium sulfate, or aluminum sulfate. This ash is collected in a dust collector or discharged through a chimney. Dry desulfurization offers advantages such as simplicity, low energy consumption, and zero wastewater generation. Existing technologies typically increase the amount of solid absorbent to meet flue gas emission standards. This not only wastes the solid absorbent, but also increases the area occupied by the desulfurization ash storage site and increases its corrosiveness.

[0003] Patent application number 202311449966.9 discloses a method for resource utilization of desulfurization ash. Desulfurization ash and limestone are mixed into a slurry and fed into a reactor with an air-permeable and waterproof layer separating the inner cavity into upper and lower parts. The reactor is then used to desulfurize flue gas containing sulfur dioxide. Although this method can reuse dry desulfurization ash, the slurry must be added to the reactor all at once before the flue gas is desulfurized. The reactor's desulfurization capacity is limited, and after desulfurization is complete, the reactor must be opened to remove the slurry, making continuous flue gas desulfurization impossible. Utility Model Content

[0004] In response to the problem that the existing technology cannot utilize desulfurization ash to continuously desulfurize flue gas, the utility model provides a desulfurization ash resource utilization device, which connects the desulfurization ash slurry separation device with the desulfurizer regeneration tank, and connects the liquid storage tank with the oxidation aeration tank and the desulfurizer regeneration tank in sequence. The desulfurizer regeneration tank is also connected to the spray layer. The unreacted desulfurizer in the desulfurization ash slurry is used to continuously desulfurize the flue gas in the wet desulfurization tower, thereby improving the utilization rate of the desulfurization ash and the desulfurization efficiency.

[0005] The technical solution of this utility model is as follows:

[0006] A desulfurization ash resource utilization device comprises a wet desulfurization tower, wherein the wet desulfurization tower is provided with a wet electrostatic precipitator, a mist eliminator, a spray layer and a liquid storage tank in order from top to bottom;

[0007] Among them, the number of spray layers is not less than two; the liquid storage tank is successively connected to the oxidation aeration tank and the desulfurizer regeneration tank, and the desulfurizer regeneration tank is also connected to the spray layer; the feeding port of the desulfurizer regeneration tank is connected to the drain port of the desulfurization ash slurry separation device, and the desulfurization ash slurry separation device is connected to the desulfurization ash storage bin. The desulfurization ash comes from the dry desulfurization process.

[0008] Further, the number of spray layers is four. The spray layer includes nozzles arranged in a geometric shape. The distance between adjacent two spray layers can be the same or different. The function of the spray layer is to uniformly atomize the rich desulfurization liquid into small droplets and fully contact with the flue gas in the desulfurization tower to remove sulfur dioxide in the flue gas.

[0009] Further, a flue gas outlet is arranged at the top of the wet desulfurization tower, and a flue gas inlet is arranged on the side wall of the wet desulfurization tower. The flue gas inlet is located on the side wall between the spray layer and the liquid storage tank and is close to the liquid storage tank. The source of the flue gas is at least one of a blast furnace stove for ironmaking, a heating furnace for rolling steel, and a gas boiler of a self-provided power plant.

[0010] Further, the drain port of the liquid storage tank is connected to the liquid inlet at the lower end of the oxidation aeration tank, and the drain port at the upper end of the oxidation aeration tank is connected to the liquid inlet at the lower end of the desulfurizer regeneration tank. The oxidation aeration tank and the desulfurizer regeneration tank are arranged outside the wet desulfurization tower. The lean desulfurization liquid in the oxidation aeration tank overflows into the desulfurizer regeneration tank through the drain port. The liquid storage tank is used to store the lean desulfurization liquid in the wet desulfurization tower. The oxidation aeration tank is used to oxidize calcium sulfite in the lean desulfurization liquid into calcium sulfate.

[0011] Further, a negative pressure device is arranged at the top of the oxidation aeration tank. The bottom of the oxidation aeration tank is connected to an oxygen supply device, and a gas distributor is arranged above the bottom of the oxidation aeration tank. The gas distributor can ensure that the oxygen generated by the oxygen supply device is evenly blown into the oxidation aeration tank from the bottom of the oxidation aeration tank to improve the oxidation efficiency.

[0012] Further, the negative pressure device is connected to an oxygen buffer tank. The negative pressure device is used to accelerate the flow of oxygen and suck the oxygen that has not participated in the oxidation reaction into the oxygen buffer tank. The gas in the oxygen buffer tank can be introduced into the oxidation aeration tank to participate in the oxidation reaction.

[0013] Further, a stirring device is arranged inside the desulfurizer regeneration tank.

[0014] Further, the oxidation aeration tank is directly connected to the desulfurizer regeneration tank or connected to the desulfurizer regeneration tank through a desulfurization ash slurry separation device. The desulfurization ash slurry separation device is a solid-liquid separation device, and the desulfurization ash slurry separation device includes a mixing chamber and a filtration chamber. The mixing chamber is used to mix desulfurization ash and / or lean desulfurization liquid with water, and the filtration chamber can separate and collect precipitated calcium salts such as calcium sulfate and calcium carbonate. The lean desulfurization liquid treated by the oxidation aeration tank can enter the desulfurization ash slurry separation device for solid-liquid separation to remove some precipitated calcium salts in the lean desulfurization liquid.

[0015] Further, a settling tank is arranged between the desulfurizer regeneration tank and the spray layer. The settling tank is used to deposit calcium salts such as calcium sulfate and calcium carbonate in the rich desulfurization liquid.

[0016] Further, the desulfurizer regeneration tank is connected to a lime supplementary feeding bin. When the sulfur content in the flue gas is relatively high, lime can be supplemented into the desulfurizer regeneration tank through the lime supplementary feeding bin to improve the desulfurization efficiency.

[0017] The beneficial effects of the present utility model are as follows:

[0018] The desulfurization ash resource utilization device provided by the present utility model is provided with a wet electrostatic precipitator and a demister, which improves the flue gas dust removal efficiency; is provided with at least two layers of spray layers, which improves the flue gas desulfurization efficiency; is provided with a desulfurization ash slurry separation device, connects the feeding port of the desulfurizer regeneration tank with the drainage port of the desulfurization ash slurry separation device, and connects the desulfurizer regeneration tank with the spray layer, prepares the desulfurization ash generated by the dry desulfurization process into desulfurization ash slurry and then uses it for desulfurizer regeneration, and repeatedly uses it for flue gas desulfurization in the wet desulfurization tower, which is beneficial to separating precipitated calcium salts such as calcium sulfate and calcium carbonate in the desulfurization ash slurry, preventing the calcium sulfate and calcium carbonate in the desulfurization ash from scaling and blocking the pipelines in the desulfurization system, and at the same time realizes continuous desulfurization and improves the desulfurization efficiency. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic diagram of the connection relationship of the desulfurization ash resource utilization device in Embodiment 1.

[0021] In the figure, 1 is a wet desulfurization tower, 2 is a wet electrostatic precipitator, 3 is a demister, 4 is a spray layer, 5 is a liquid storage tank, 6 is an oxidation aeration tank, 7 is a desulfurizer regeneration tank, 8 is a negative pressure device, 9 is a gas distributor, 10 is an oxygen buffer tank, 11 is a desulfurization ash slurry separation device, 12 is a sedimentation tank, 13 is a desulfurization ash storage bin, 14 is a water storage tank, 15 is a lime supplementary feeding bin, and 16 is a flue gas inlet. Detailed implementation mode

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Embodiment 1

[0024] A desulfurization ash resource utilization device, as Figure 1 shown, includes a wet desulfurization tower 1. A flue gas outlet is arranged at the top of the wet desulfurization tower 1. A wet electrostatic precipitator 2, a demister 3, a spray layer 4 and a liquid storage tank 5 are successively arranged in the wet desulfurization tower 1 from top to bottom. A flue gas inlet 16 is arranged on the side wall of the wet desulfurization tower 1 between the spray layer 4 and the liquid storage tank 5 and close to the liquid storage tank 5.

[0025] Among them, the number of the spray layers 4 is four. The spray layers 4 from top to bottom are the first spray layer, the second spray layer, the third spray layer and the fourth spray layer respectively. The first to fourth spray layers are all provided with nozzles distributed in a ring shape, and the nozzles of adjacent two spray layers are staggered to ensure uniform spraying. The distance between the first spray layer and the second spray layer is equal to the distance between the third spray layer and the fourth spray layer, and the distance between the first spray layer and the second spray layer is less than the distance between the second spray layer and the third spray layer. The drain outlet of the liquid storage tank 5 is communicated with the inlet of the lower end of the oxidation aeration tank 6. A negative pressure device 8 is arranged at the top of the oxidation aeration tank 6, and the negative pressure device 8 is communicated with the oxygen buffer tank 10. A gas distributor 9 is arranged above the bottom of the oxidation aeration tank 6, and the bottom of the oxidation aeration tank 6 is communicated with an oxygen supply device. The drain outlet at the upper end of the oxidation aeration tank 6 is respectively communicated with the inlet of the lower end of the desulfurizer regeneration tank 7 and the desulfurization ash slurry separation device 11 through pipelines. A three-way valve is arranged on the pipeline so that the lean desulfurization liquid discharged from the drain outlet at the upper end of the oxidation aeration tank 6 can enter the inlet of the lower end of the desulfurizer regeneration tank 7 or the desulfurization ash slurry separation device 11 as required. The desulfurizer regeneration tank 7 is also provided with a feeding port and a replenishing port. The feeding port of the desulfurizer regeneration tank 7 is communicated with the drain outlet of the desulfurization ash slurry separation device 11, and the replenishing port of the desulfurizer regeneration tank 7 is communicated with the lime replenishing bin 15. The desulfurization ash slurry separation device 11 is a filtering device. The desulfurization ash slurry separation device 11 includes a mixing chamber and a filtering chamber. The mixing chamber is provided with a first feed port and a second feed port, and the filtering chamber is provided with a drain outlet. The first feed port is communicated with the desulfurization ash storage bin 13 and the drain outlet at the upper end of the oxidation aeration tank 6 through a branch pipeline, and the second feed port is communicated with the water storage tank 14 through a pipeline. A stirring device is arranged inside the desulfurizer regeneration tank 7. The discharge port of the desulfurizer regeneration tank 7 is successively communicated with the sedimentation tank 12 and the spray layer 4 through pipelines. Both the oxidation aeration tank 6 and the desulfurizer regeneration tank 7 are arranged outside the wet desulfurization tower 1.

[0026] Working principle: The flue gas from the steel rolling heating furnace enters the wet desulfurization tower through the flue gas inlet for spray desulfurization. The lean desulfurization liquid generated during the spray desulfurization process falls into the liquid storage tank. The lean desulfurization liquid in the liquid storage tank first enters the oxidation aeration tank. In the oxidation aeration tank, calcium sulfite in the lean desulfurization liquid reacts with oxygen to form calcium sulfate. The unreacted oxygen is sucked into the oxygen buffer bottle by the negative pressure device. The lean desulfurization liquid treated by the oxidation aeration tank can directly enter the desulfurizer regeneration tank, or it can first enter the desulfurization ash slurry separation device to filter out the precipitated calcium sulfate and calcium carbonate and then enter the desulfurizer regeneration tank. The desulfurization ash in the desulfurization ash storage bin is the desulfurization ash generated by the dry desulfurization process. The desulfurization ash contains lime that has not participated in the desulfurization reaction. The desulfurization ash is mixed evenly with the water in the water storage tank in the mixing chamber of the desulfurization ash slurry separation device to obtain the desulfurization ash slurry. The desulfurization ash slurry then enters the filtration chamber for filtration to remove calcium sulfate and calcium carbonate in the desulfurization ash. The filtrate containing calcium hydroxide and calcium oxide enters the desulfurizer regeneration tank to be mixed with the lean desulfurization liquid for regeneration treatment to obtain the rich desulfurization liquid. When the sulfur content in the flue gas is relatively high, lime can be added to the desulfurizer regeneration tank through the lime supplementary feeding bin to increase the calcium oxide content in the rich desulfurization liquid. The rich desulfurization liquid enters the sedimentation tank from the desulfurizer regeneration tank for sedimentation to remove the precipitated calcium salts such as calcium sulfate and calcium carbonate again, and finally enters the wet desulfurization tower for spray desulfurization. The insoluble substances containing calcium carbonate obtained from the desulfurization ash slurry separation device and the sedimentation tank can be used for processing gypsum.

[0027] Although the present utility model has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present utility model is not limited thereto. Without departing from the spirit and essence of the present utility model, those of ordinary skill in the art can make various equivalent modifications or substitutions to the embodiments of the present utility model, and these modifications or substitutions should all be within the scope covered by the present utility model. / Any person familiar with the technical field of the present utility model can easily think of changes or substitutions within the technical scope disclosed by the present utility model, and all should be covered within the protection scope of the present utility model.

Claims

1. A device for resource utilization of desulfurized ash, comprising a wet desulfurization tower, characterized in that, The wet desulfurization tower is successively provided with a wet electrostatic precipitator, a demister, a spray layer and a liquid storage tank from top to bottom; Among them, the number of spray layers is not less than two; the liquid storage tank is successively communicated with an oxidation aeration tank and a desulfurizer regeneration tank, and the desulfurizer regeneration tank is also communicated with the spray layer; the feeding port of the desulfurizer regeneration tank is communicated with the drainage port of the desulfurization ash slurry separation device, and the desulfurization ash slurry separation device is communicated with the desulfurization ash storage bin, and the desulfurization ash comes from the dry desulfurization process.

2. The desulfurized ash resource utilization device according to claim 1, characterized in that, The number of spray layers is four.

3. The desulfurization ash resource utilization device according to claim 1, characterized in that, A flue gas outlet is arranged at the top of the wet desulfurization tower, and a flue gas inlet is arranged on the side wall of the wet desulfurization tower. The flue gas inlet is located on the side wall between the spray layer and the liquid storage tank.

4. The desulfurized ash resource utilization device according to claim 1, wherein The drainage port of the liquid storage tank is communicated with the liquid inlet at the lower end of the oxidation aeration tank, and the drainage port at the upper end of the oxidation aeration tank is communicated with the liquid inlet at the lower end of the desulfurizer regeneration tank.

5. The resource utilization device for desulfurized ash according to claim 1, wherein A negative pressure device is arranged at the top of the oxidation aeration tank. The bottom of the oxidation aeration tank is communicated with an oxygen supply device, and a gas distributor is arranged above the bottom of the oxidation aeration tank.

6. The desulfurized ash resource utilization device according to claim 5, characterized in that, The negative pressure device is communicated with an oxygen buffer tank.

7. The desulfurized ash resource utilization device according to claim 1, characterized in that A stirring device is arranged inside the desulfurizer regeneration tank.

8. The desulfurized ash resource utilization device according to claim 1, characterized in that, The oxidation aeration tank is directly communicated with the desulfurizer regeneration tank or is communicated with the desulfurizer regeneration tank through the desulfurization ash slurry separation device.

9. The desulfurized ash resource utilization device according to claim 1, wherein, A settling tank is arranged between the desulfurizer regeneration tank and the spray layer.

10. The desulfurized ash resource utilization device according to claim 1, characterized in that, The desulfurizer regeneration tank is communicated with a lime supplementary feeding bin.

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