A methyltrichlorosilane-containing exhaust gas treatment system

Abstract

The utility model discloses a kind of methyltrichlorosilane-containing waste gas treatment systems, including buffer tank, jet tower, water pump, primary scrubber, secondary scrubber, liquid seal tank, jet device, fire arrester, waste gas duct, water pump pipeline, chimney, spray pipeline, circulating pump, blowdown valve, nitrogen pipe interface.The utility model passes through the washing liquid of venturi high-speed flow and generates negative pressure, introduces the waste gas of previous section into waste gas treatment system, full-course sealing does not contact air, methyltrichlorosilane-containing waste gas is handled, and methyltrichlorosilane waste gas treatment effect is remarkable and high safety.

Description

Technical Field

[0001] This utility model relates to the field of waste gas treatment technology, and in particular to a waste gas treatment system containing methyltrichlorosilane. Background Technology

[0002] Combustion of methyltrichlorosilane produces molten silica, which can accumulate and clog equipment. If not properly controlled, it can also produce highly toxic substances such as dioxins, seriously harming the environment and human health. When it comes into contact with water, it is easily hydrolyzed to produce hydrogen chloride, which causes severe corrosion to metal equipment and pipelines, shortening the life of the equipment.

[0003] Traditional methods of compressing air using mechanical fans pose safety hazards. The use of shaft seals in fans can easily lead to air leaks and malfunctions. Direct contact between the fan impeller and internal components and toxic or corrosive gases can cause corrosion, and internal damage can affect the normal operation of the system. Mechanical friction and static electricity from the fan can also generate sparks, creating potential hazards. Furthermore, during system startup, it is necessary to check whether the fan's internal components have been inerted with nitrogen, increasing the difficulty of inspection.

[0004] Therefore, it is necessary to provide a new type of exhaust gas treatment system containing methyltrichlorosilane to solve the current problems and improve exhaust gas treatment efficiency. Utility Model Content

[0005] This invention provides a waste gas treatment system containing methyltrichlorosilane, which is a collection and treatment system constructed by a venturi jet system, an alkaline washing system, a liquid sealing system, and a nitrogen inerting system that do not rely on a fan.

[0006] The technical solution is as follows: A waste gas treatment system containing methyltrichlorosilane includes a buffer tank, a jet tower, a primary scrubbing tower, a secondary scrubbing tower, and a liquid seal tank arranged sequentially according to the waste gas flow direction; the buffer tank, jet tower, primary scrubbing tower, secondary scrubbing tower, and liquid seal tank are connected sequentially by waste gas ducts; the buffer tank is equipped with a nitrogen inlet; the jet tower is equipped with an ejector, the jet circulation tower is connected to a water pump, the water pump is connected to a water pump pipeline, and both the primary and secondary scrubbing towers are equipped with spray pipelines; the jet circulation tower, primary scrubbing tower, and secondary scrubbing tower are all equipped with circulation pumps; and the top of the liquid seal tank is equipped with a chimney.

[0007] Furthermore, the entire processing system is made of fiberglass and 316L stainless steel.

[0008] Furthermore, the jet injector, jet tower, water pump, and water pump pipeline are combined to form a jet system, which provides negative pressure to introduce the exhaust gas from the front end.

[0009] Furthermore, both the primary and secondary scrubbing towers are equipped with drain valves, which ensure timely drainage and prevent pipe nozzle blockage.

[0010] Furthermore, the chimney is equipped with a nitrogen inlet to prevent outside air from entering the interior.

[0011] Furthermore, a flame arrester is installed on the chimney to prevent backfire.

[0012] The embodiments of this utility model have the following beneficial effects: This invention uses a high-speed flowing washing liquid in a Venturi tube to generate negative pressure, introducing the upstream waste gas into the waste gas treatment system. The entire process is sealed and does not come into contact with air, thus treating waste gas containing methyltrichlorosilane. The treatment effect of methyltrichlorosilane waste gas is significant and the safety is high. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation Example:

[0014] See Figure 1 A waste gas treatment system containing methyltrichlorosilane includes a buffer tank 1, a jet circulation tower 2, a water pump 3, a primary scrubbing tower 4, a secondary scrubbing tower 5, a liquid seal tank 6, a jet injector 7, a flame arrester 8, a waste gas duct 9, a water pump pipeline 10, a chimney 11, a spray pipeline 12, a circulation pump 13, a drain valve 14, and a nitrogen inlet 15.

[0015] The system is arranged in sequence according to the direction of exhaust gas flow, including a buffer tank 1, a jet circulation tower 2, a primary scrubbing tower 4, a secondary scrubbing tower 5, and a liquid seal tank 6. The buffer tank 1, jet circulation tower 2, primary scrubbing tower 4, secondary scrubbing tower 5, and liquid seal tank 6 are connected in sequence by exhaust gas ducts 9.

[0016] The buffer tank 1 is equipped with a nitrogen inlet 15.

[0017] The jet circulation tower 2 is equipped with a jet injector 7. The jet circulation tower 2 is connected to a water pump 3. The water pump 3 is connected to a water pump pipeline 10. The jet injector 7, the jet circulation tower 2, the water pump 3, and the water pump pipeline 10 are combined to form a jet system.

[0018] Both the primary scrubbing tower 4 and the secondary scrubbing tower 5 are equipped with spray pipes 12.

[0019] Both the primary scrubbing tower 4 and the secondary scrubbing tower 5 are equipped with drain valves 14.

[0020] The jet circulation tower 2, the primary washing tower 4, and the secondary washing tower 5 are all equipped with circulation pumps 13.

[0021] The top of the liquid-sealed tank 6 is equipped with a chimney 11. The treated exhaust gas is finally discharged into the atmosphere through the chimney 11. A nitrogen inlet 15 is installed on the chimney 11 to prevent outside air from entering the interior. A flame arrester 8 is installed on the chimney 11 to prevent backfire.

[0022] The entire waste gas treatment system employs fully enclosed piping and equipment installation from the exhaust gas from the process equipment to the final outlet of the treatment equipment, prohibiting any unnecessary openings. The system as a whole is constructed of fiberglass and 316L stainless steel to prevent the highly corrosive reactants from methyltrichlorosilane waste gas during treatment from corroding the equipment and piping, shortening the equipment's service life, and reducing the risk of leaks.

[0023] Before introducing exhaust gas into the system, introduce stable nitrogen gas to maintain a slight positive pressure throughout the system. As long as the internal system pressure remains slightly higher than the external atmospheric pressure, air cannot flow back into the system from the leak point. Install pressure reducing valves and precision pressure regulating valves on the nitrogen supply line, and install a liquid seal tank at the end of the system to maintain a stable system pressure.

[0024] Install oxygen analyzers: Install online oxygen analyzers at key locations in the system, including the main exhaust pipe and the terminal outlet, to monitor the oxygen concentration within the system in real time. Interlock the oxygen concentration signal with the system control center. Set a safety threshold of oxygen concentration <3%. If the oxygen concentration exceeds this threshold, the system should immediately alarm and automatically initiate emergency measures, increasing the nitrogen purging flow, cutting off the exhaust gas source, and initiating the emergency shutdown procedure.

[0025] After being collected in a sealed environment isolated from air, the exhaust gas enters buffer tank 1 for pressure stabilization and condensation of some methyltrichlorosilane. The condensed waste liquid can be discharged periodically to reduce the load on the treatment system.

[0026] The ejector 7 uses the high-speed jetting action of water to generate negative pressure to achieve the purpose of vacuuming. At the same time, sodium hydroxide and waste gas come into full contact inside the ejector, which achieves the effect of removing methyltrichlorosilane from the waste gas.

[0027] The exhaust gas treated by the jet system then enters the downstream alkaline washing system. In the primary and secondary washing towers, the exhaust gas fully contacts and reacts with the sodium hydroxide circulating liquid to further remove residual hydrogen chloride, methyltrichlorosilane, etc., ensuring that the end emission meets the standards. The silica produced during the reaction is discharged in time through the bottom drain valve 14 to prevent pipe nozzle blockage. The hydrogen chloride produced in the reaction reacts with the NaOH solvent in time.

[0028] A pressure transmitter is installed on the front-end pipeline of the jet system, interlocked with the variable frequency motor of the water pump to control the negative pressure at the front end. Simultaneously, a pressure transmitter, thermocouple, level gauge, and other instruments are installed on the supporting circulation tank to monitor the temperature, pressure, and circulating water volume of the exhaust gas in the jet system, ensuring normal system operation. The system is equipped with a pH meter, interlocked with the system's chemical dosing and sewage discharge, to ensure that the circulating liquid in the system remains alkaline.

[0029] The Venturi system, consisting of water pump 3, water pump pipeline 10, and ejector 7, provides negative pressure to introduce upstream exhaust gas.

[0030] The washing tower is equipped with level gauges and system water replenishment / drainage interlocks, and the pumps are stopped when the liquid level is low to protect them. A differential pressure transmitter is installed on the washing tower to monitor the system's differential pressure, ensuring it remains normal and unobstructed. A pH meter is also installed and interlocked with the dosing and draining of the alkaline washing tower to ensure the circulating liquid in the system remains alkaline. The dosing system consists of a liquid alkali storage tank and a dosing pump, interlocked with the pH levels of each washing system to administer chemicals and ensure the alkalinity of the circulating liquid in each system. A radar level gauge is installed on the liquid alkali storage tank to monitor the sodium hydroxide level, and the dosing pump is interlocked when the liquid level is low to prevent the pump from running dry.

[0031] A level gauge is installed on the liquid-sealed tank 6 to monitor the liquid level inside the tube, ensuring that the interior is always in a liquid-sealed state.

[0032] The above are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A waste gas treatment system containing methyltrichlorosilane, characterized in that: It includes a buffer tank, a jet tower, a primary scrubbing tower, a secondary scrubbing tower, and a liquid seal tank arranged sequentially according to the direction of exhaust gas flow; the buffer tank, jet tower, primary scrubbing tower, secondary scrubbing tower, and liquid seal tank are connected sequentially by exhaust gas ducts; the buffer tank is equipped with a nitrogen inlet; the jet tower is equipped with an ejector, the jet tower is connected to a water pump, the water pump is connected to a water pump pipeline, and both the primary and secondary scrubbing towers are equipped with spray pipelines; the jet tower, primary scrubbing tower, and secondary scrubbing tower are all equipped with circulation pumps; and the top of the liquid seal tank is equipped with a chimney.

2. The methyltrichlorosilane-containing waste gas treatment system according to claim 1, characterized in that: The entire processing system is made of fiberglass and 316L stainless steel.

3. The methyltrichlorosilane-containing waste gas treatment system according to claim 1, characterized in that: The jet injector, jet tower, water pump, and water pump pipeline are combined to form a jet system, which provides negative pressure to introduce the exhaust gas from the front end.

4. The methyltrichlorosilane-containing waste gas treatment system according to claim 1, characterized in that: Both the primary and secondary scrubbing towers are equipped with drain valves, which ensure timely drainage and prevent pipe nozzle blockage.

5. The methyltrichlorosilane-containing waste gas treatment system according to claim 1, characterized in that: The chimney is equipped with a nitrogen inlet to prevent outside air from entering.

6. The methyltrichlorosilane-containing waste gas treatment system according to claim 1, characterized in that: A flame arrester is installed on the chimney to prevent backfire.

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