Iron phosphate tail gas treatment system

Abstract

The utility model relates to an iron phosphate tail gas treatment system. The device is characterized in that an air inlet of a fan is connected with an acidic tail gas pipe, an air outlet of the fan is connected with a cyclone separator, an air outlet in the top of the cyclone separator is connected to a circulating water tank, an outlet of the circulating water tank is connected with a circulating pipe through a circulating spraying pump, the other end of the circulating pipe is connected with two branch pipes, one branch pipe is connected to a spraying pipe of the sprayer, and the other branch pipe is connected with a spraying pipe of the sprayer. The other branch pipe is connected with a third electric valve and connected into the filler, and a second electric valve is arranged on the circulating pipe; an outlet of the alkali liquor preparation tank is connected with an alkali liquor pipe through a delivery pump; and the alkali liquor pipe is connected into the circulating water tank. The cyclone separator is used for carrying out primary gas-liquid separation on the acidic tail gas and then treating the acidic tail gas, and a large amount of acidic water mist in the cyclone separator can be condensed and enriched and then discharged, so that the treatment burden of the tail gas spray tower can be effectively reduced, and the replacement period of spray liquid in a circulating water tank in the tail gas spray tower can be effectively prolonged; the consumption of alkali liquor and the generation of waste liquid can be reduced.

Description

Technical Field

[0001] This utility model belongs to the field of environmental protection devices, specifically relating to a ferric phosphate tail gas treatment system. Background Technology

[0002] With the further development of new energy sources in China, electricity, as a clean energy source, is gradually replacing petroleum. Currently, lithium iron phosphate (LFP) batteries are becoming the mainstream choice for battery cathode materials due to their lower cost, and iron phosphate is one of the main raw materials for LFP cathode materials. The domestic ammonia-based LFP process mainly uses ferrous sulfate as the iron source and monoammonium phosphate as the phosphorus source, producing LFP through a series of synthesis, aging, and calcination processes. This production process easily generates sulfuric acid-containing tail gas. With increasingly stringent environmental protection requirements, higher demands are being placed on the treatment of LFP tail gas. Existing LFP tail gas environmental protection devices mostly utilize staged spray scrubbing processes to treat acidic tail gas and achieve emission standards. These devices generally suffer from high costs, large footprints, and high energy consumption. Summary of the Invention

[0003] The purpose of this invention is to solve the problem of acidic tail gas treatment generated in the current iron phosphate production process and to provide an iron phosphate tail gas treatment system.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a ferric phosphate tail gas treatment system, comprising a spray tower, with packing material at the top, a sprayer in the middle and upper part, and a circulating water tank at the bottom, characterized in that: the air inlet of the blower is connected to an acidic tail gas pipe, the air outlet of the blower is connected to a cyclone separator, the air outlet at the top of the cyclone separator is connected to the circulating water tank, the outlet of the circulating water tank is connected to a circulating pipe via a circulating spray pump, the other end of the circulating pipe is connected to two branch pipes, one branch pipe is connected to the spray pipe of the sprayer, and the other branch pipe is connected to a No. 3 electric valve and connected to the packing material, and a No. 2 electric valve is provided on the circulating pipe; the outlet of the alkali preparation tank is connected to an alkali pipe via a delivery pump, the alkali pipe is connected to the circulating water tank, and a No. 5 electric valve is provided on the alkali pipe.

[0005] The spray tower's circulating water tank is connected to a production water pipe for replenishing water, and the production water pipe is equipped with an electric valve.

[0006] The circulating water tank of the spray tower is equipped with a level gauge and a pH meter.

[0007] The exhaust pipe at the top of the spray tower is connected to the exhaust gas emission system.

[0008] The circulation pipe is connected to the drain pipe, and the drain pipe is equipped with a No. 4 electric valve.

[0009] The alkaline solution preparation tank is equipped with a stirrer.

[0010] The main structure of the cyclone separator and spray tower is made of fiberglass.

[0011] The beneficial effects of this invention are as follows: A cyclone separator is used to perform preliminary gas-liquid separation of acidic exhaust gas before further treatment. In the cyclone separator, a large amount of acidic water mist condenses and accumulates before being discharged, effectively reducing the processing burden on the exhaust gas scrubbing tower. The replacement cycle of the spray liquid in the internal circulating water tank of the exhaust gas scrubbing tower is effectively extended, reducing the consumption of alkali solution and the generation of waste liquid. The main structure of the cyclone separator and exhaust gas scrubbing tower is made of fiberglass, making it more cost-effective. Furthermore, the system adopts an automatic control system, achieving unattended operation and making it more reliable. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the present invention;

[0013] In the diagram: 1-fan, 2-cyclone separator, 3-spray tower, 31-spray pipe, 32-packing, 33-level gauge, 34-pH meter; 4-circulating spray pump, 5-transfer pump, 6-alkali preparation tank, 7-stirrer; L1-production water pipe, L2-circulation pipe, L3-alkali pipe, L4-drain pipe; F1-electric valve No. 1, F2-electric valve No. 2, F3-electric valve No. 3, F4-electric valve No. 4, F5-electric valve No. 5. Detailed Implementation

[0014] Example 1, see Figure 1 A ferric phosphate tail gas treatment system includes a spray tower 3, with packing material 32 on the upper part, a sprayer in the middle and upper part, and a circulating water tank at the bottom. The system is characterized by: an air inlet of a blower 1 connected to an acidic tail gas pipe, an air outlet of the blower 1 connected to a cyclone separator 2, an air outlet at the top of the cyclone separator 2 connected to the circulating water tank, and an outlet of the circulating water tank connected to a circulating pipe L2 via a circulating spray pump 4. The other end of the circulating pipe L2 is connected to two branch pipes; one branch pipe is connected to the spray pipe 31 of the sprayer, and the other branch pipe is connected to a third electric valve F3 and connected to the packing material 32. A second electric valve F2 is installed on the circulating pipe L2. The outlet of an alkali preparation tank 6 is connected to an alkali pipe L3 via a transfer pump 5. The alkali pipe L3 is connected to the circulating water tank, and a fifth electric valve F5 is installed on the alkali pipe L3. A stirrer 7 is installed inside the alkali preparation tank 6.

[0015] The circulating water tank of the spray tower 3 is connected to the production water pipe L1 for water replenishment, and the production water pipe L1 is equipped with an electric valve F1.

[0016] The circulating water tank of the spray tower 3 is equipped with a level gauge 33 and a pH meter 34.

[0017] The exhaust pipe at the top of the spray tower 3 is connected to the exhaust gas emission system.

[0018] The circulation pipe L2 is connected to the drain pipe L4, and the drain pipe L4 is equipped with a No. 4 electric valve F4.

[0019] The main structures of the cyclone separator 2 and the spray tower 3 are made of fiberglass.

[0020] Working process: Acidic exhaust gas enters cyclone separator 2 through exhaust gas fan 1. In cyclone separator 2, the water and water-soluble acid in the acidic exhaust gas are initially condensed and settled under the action of gravity and centrifugal force. The unsettled liquid enters the circulating water pool at the bottom of exhaust gas spray tower 3 through the duct. When the liquid level in the circulating water pool is low and the pH value meets the requirements, electric valve F1 is opened to replenish water. Level gauge 33 is used to monitor the liquid level in the circulating water pool, and pH meter is used to monitor the pH value of the circulating water. When the exhaust gas enters spray tower 3, spray pipe 31 begins to spray alkaline solution to further neutralize and absorb the acidic exhaust gas. The neutralized exhaust gas then goes to the exhaust gas emission system through the duct at the top of spray tower 3.

[0021] Electric valve F3 (No. 3) is used to control the internal water replenishment of packing material 32. Electric valves F2 (No. 2) and F4 (No. 4) are used to switch the destination of circulating water. When the pH of the circulating water meets the requirements, electric valve F2 (No. 2) is opened, electric valve F4 (No. 4) is closed, and the circulating spray pump 4 is started. When the pH of the circulating water does not meet the requirements and the circulating water needs to be replaced, electric valve F2 (No. 2) is closed, electric valve F4 (No. 4) is opened, and the waste liquid is discharged.

[0022] Alkali preparation tank 6 is used to prepare alkali solution, and stirrer 7 is turned on to dissolve it. When the pH of the circulating water pool at the bottom of spray tower 3 is low, open electric valve F5 to start transfer pump 5 to add alkali solution. When the pH reaches the required level, stop transfer pump 5 and close electric valve F5 to complete the addition of alkali solution.

Claims

1. A phosphoric acid iron tail gas treatment system comprising a spray tower (3), the upper part of the spray tower (3) being provided with a filler (32), the middle and upper parts being provided with a sprayer, and the bottom being provided with a circulating pool, characterized in that: The air inlet of the fan (1) is connected with the acid tail gas pipe, the air outlet of the fan (1) is connected with the cyclone separator (2), the air outlet at the top of the cyclone separator (2) is connected with the circulating water tank, the outlet of the circulating water tank is connected with the circulating pipe (L2) through the circulating spray pump (4), the other end of the circulating pipe (L2) is connected with two branch pipes, one branch pipe is connected with the spray pipe (31) of the sprayer, the other branch pipe is connected with the third electric valve (F3) and is connected into the filler (32), the circulating pipe (L2) is provided with the second electric valve (F2); the outlet of the lye preparation tank (6) is connected with the lye pipe (L3) through the delivery pump (5), the lye pipe (L3) is connected with the circulating water tank, the lye pipe (L3) is provided with the fifth electric valve (F5).

2. An iron phosphate off-gas treatment system as claimed in claim 1, characterized in that: The circulating water tank of the spray tower (3) is connected with the production water pipe (L1) for water supplement, the production water pipe (L1) is provided with the first electric valve (F1).

3. The iron phosphate off-gas treatment system of claim 1, wherein: The circulating water tank of the spray tower (3) is provided with the liquid level meter (33) and the pH meter (34).

4. The iron phosphate off-gas treatment system of claim 1, wherein: The exhaust pipe at the top of the spray tower (3) is connected with the tail gas discharge system.

5. An iron phosphate off-gas treatment system as claimed in claim 1, characterized by: The circulating pipe (L2) is connected with the liquid discharge pipe (L4), the liquid discharge pipe (L4) is provided with the fourth electric valve (F4).

6. An iron phosphate off-gas treatment system as claimed in claim 1, characterized by: The lye preparation tank (6) is provided with the stirrer (7).

7. An iron phosphate off-gas treatment system as claimed in any one of claims 1 to 6, characterized in that: The main body structure of the cyclone separator (2) and the spray tower (3) is made of glass steel.

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