Electric heating water washing type semiconductor tail gas treatment equipment and treatment process thereof

Abstract

The invention provides electric heating water washing type tail gas treatment equipment which comprises a gas inlet pipe, a main cavity, a heating rod, a reaction cavity, a cooling cavity, a water tank and a gas-liquid separation cavity, the gas inlet pipe is connected with the main cavity, the main cavity is connected with the reaction cavity, the lower end of the reaction cavity is connected with the cooling cavity, the cooling cavity is connected with the water tank, and the water tank is connected with the heating rod. The water tank is connected with the gas-liquid separation cavity; the gradient of the air inlet pipe is 0.3%-0.5%; the gas-liquid separation cavity comprises a first exhaust cavity, a second exhaust cavity and an acid discharge pipe; the first exhaust cavity is fixedly connected with the second exhaust cavity through a flange; and the second exhaust cavity is fixedly connected with the acid discharge pipe through a flange. The invention further provides an electric heating water washing type tail gas treatment process. The tail gas treatment equipment provided by the invention is simple in structure and corrosion-resistant; according to the electric heating water washing type tail gas treatment process, accelerated corrosion of materials in the water washing system is prevented, the service life of equipment is prolonged, the cost is saved, and the tail gas treatment efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor tail gas treatment, and in particular to an electric heating water washing type semiconductor tail gas treatment device and a treatment process thereof. Background Art

[0002] Many chemicals and process gases used in semiconductor production are highly toxic, flammable or explosive. 4 , HF, etc., directly discharged into the atmosphere will threaten the lives of workers and surrounding residents. If these harmful gases are not treated, they may cause acute or chronic poisoning, causing serious damage to the respiratory system, skin and eyes. For example, VOCs participate in atmospheric photochemical reactions to form ozone and secondary organic aerosols, exacerbating air pollution problems. Therefore, local environmental protection departments have formulated strict industrial waste gas emission standards, requiring enterprises to purify the waste gas they emit and only discharge it into the atmosphere after reaching the prescribed emission limit.

[0003] Semiconductor tail gas treatment technology can be divided into combustion tail gas treatment technology, plasma tail gas treatment technology and electric heating tail gas treatment technology. Among them, combustion tail gas treatment technology mainly includes direct combustion and catalytic combustion. In the direct combustion method, the tail gas is sent into a high-temperature combustion chamber to fully burn the organic matter in it and convert it into harmless substances such as carbon dioxide and water. Catalytic combustion is to achieve the same oxidation process by lowering the reaction temperature in the presence of a catalyst, which is energy-saving and easier to control. Plasma tail gas treatment technology is a method of treating tail gas by using high-voltage discharge to generate non-equilibrium plasma. The electrons and active particles (such as ions and free radicals) in the plasma have extremely high energy and can efficiently crack and oxidize organic pollutants and some inorganic pollutants in the tail gas. The electric heating water washing semiconductor tail gas treatment is a tail gas purification technology for acidic, alkaline gases and other harmful organic pollutants generated in the semiconductor manufacturing process. Generally, the exhaust gas entering the tail gas processor is preheated by an electric heating device so that the harmful components therein are more easily chemically reacted or physically adsorbed with water or other solvents. Subsequently, the preheated exhaust gas is contacted with the heated scrubbing liquid (usually deionized water or a solution with added chemicals) through a spray system, and the pollutants dissolve under high temperature conditions or react with the chemical reagents in the scrubbing liquid to produce treatable byproducts. After water washing, the mixture will further pass through the equipment to separate the liquid from the gas, ensuring that most of the harmful components remain in the water, while the clean gas can be discharged.

[0004] However, in the electrically heated water-washed semiconductor exhaust treatment, high temperature and acid-base environment may cause accelerated corrosion of internal system materials, affecting the service life and maintenance costs of the equipment; in addition, the existing electrically heated water-washed semiconductor exhaust treatment has low treatment efficiency.

[0005] Therefore, the prior art needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to provide an electrically heated water-washed semiconductor tail gas treatment device and a treatment process thereof in view of the deficiencies of the prior art. Based on the above problems, the present invention proposes an electrically heated water-washed semiconductor tail gas treatment process, which prevents the accelerated corrosion of the internal materials of the water washing system, prolongs the service life of the equipment, saves costs, and improves the efficiency of tail gas treatment by improving the water washing efficiency, the high temperature decomposition efficiency, and the chemical reaction efficiency.

[0007] The technical solution of the present invention is achieved in this way:

[0008] An electrically heated water-washed semiconductor tail gas treatment equipment, characterized in that it includes an air intake pipe, a main cavity, a heating rod, a reaction cavity, a cooling cavity, a water tank and a gas-liquid separation cavity, the air intake pipe is connected to the main cavity, the heating rod is arranged on the main cavity and extends into the reaction cavity, the main cavity is connected to the reaction cavity, the lower end of the reaction cavity is connected to the cooling cavity, the cooling cavity is connected to the water tank, and the water tank is connected to the gas-liquid separation cavity; the air intake pipe 1 is set with a slope of 0.3% to 0.5%; the gas-liquid separation cavity includes a first exhaust cavity, a second exhaust cavity and an acid exhaust pipe; the first exhaust cavity and the second exhaust cavity are fixedly connected by a flange; the second exhaust cavity and the acid exhaust pipe are fixedly connected by a flange.

[0009] As described above, in the electrically heated water-washed semiconductor tail gas treatment equipment, the reaction chamber is provided with a first cavity layer, a second cavity layer and a third cavity layer from the outside to the inside in sequence, and a sealed inner cavity is formed between the first cavity layer and the second cavity layer, and circulating cooling water enters the sealed inner cavity under the action of a circulating pump.

[0010] As described above, in the electrically heated water-washed semiconductor tail gas treatment equipment, the interior of the third cavity layer is coated with a high temperature resistant and corrosion resistant material.

[0011] As described above, the electrically heated water-washed semiconductor tail gas treatment equipment, the water tank is provided with a water inlet pipe, a first water spray pipe, a second water spray pipe and a third water spray pipe, the water inlet pipe is connected to the first water spray pipe, the second water spray pipe and the third water spray pipe respectively.

[0012] As described above, in the electrically heated water-washed semiconductor exhaust treatment equipment, the first water spray pipe and the third water spray pipe are arranged horizontally and perpendicular to each other; the second water spray pipe and the third water spray pipe are arranged horizontally and perpendicular to each other; the first water spray pipe, the second water spray pipe and the third water spray pipe are in the same plane.

[0013] As described above, in the electrically heated water-washed semiconductor tail gas treatment equipment, the heights of the first water spray pipe, the second water spray pipe and the third water spray pipe are lower than the upper cover plate of the water tank.

[0014] As described above, in the electrically heated water-washed semiconductor tail gas treatment equipment, a plurality of nozzles are provided on the first water spray pipe, the second water spray pipe and the third water spray pipe.

[0015] Based on the same inventive concept, the present invention provides an electrically heated water-washed tail gas treatment process, using the electrically heated water-washed tail gas treatment equipment as described above, comprising the following steps:

[0016] S1. High-temperature decomposition of tail gas: The pre-treated semiconductor tail gas enters through the air inlet pipe, then enters the main cavity, and finally enters the reaction cavity. The heating rod in the reaction cavity electrically heats the tail gas for high-temperature decomposition. The reaction cavity is sequentially provided with a first cavity layer, a second cavity layer, and a third cavity layer from the outside to the inside. A sealed inner cavity is formed between the first cavity layer and the second cavity layer. The circulating cooling water enters the sealed inner cavity under the action of the circulating pump. The tail gas enters the cooling cavity after being cooled by the circulating cooling water, and then flows into the water tank;

[0017] S2. Tail gas washing: The tail gas decomposed by high temperature enters the water tank through the cooling chamber, and the tail gas contacts the water in the water tank to treat harmful gases that can be dissolved by water or undergo chemical reactions to generate soluble salts;

[0018] S3. Water vapor separation of tail gas: The tail gas after water washing passes through the gas-liquid separation chamber for water vapor separation.

[0019] In the above-mentioned electrically heated water-washed tail gas treatment process, the temperature in step S1 is 600°C to 1000°C.

[0020] In the above-mentioned electric heating water washing tail gas treatment process, the gas flow rate of the pre-treated semiconductor tail gas entering through the air inlet pipe 1 is 0.1 to 30 m / s.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] 1. The electric heating water-washing tail gas treatment equipment provided by the present invention uses electric heating to generate high temperature, which not only provides the advantages of strong controllability and fast response speed, but also is cleaner and more efficient than traditional combustion heating. Harmful substances in tail gas will undergo a series of chemical reactions such as cracking and oxidation after being exposed to high temperature, converting toxic and harmful components into relatively harmless or easy-to-handle forms; and the electric heating water-washing tail gas treatment equipment provided by the present invention has a simple structure and is corrosion-resistant.

[0023] 2. In the electric heating water-washing exhaust gas treatment equipment provided by the present invention, the first water spray pipe, the second water spray pipe and the third water spray pipe are in the same plane, forming a three-dimensional cross-spraying network. Such a three-dimensional layout ensures that the exhaust gas can be in full contact with the spray water after entering the water tank, increasing the contact area between the gas and the water, thereby improving the speed and effect of the dissolution or chemical reaction of harmful substances.

[0024] 3. The present invention provides an electric heating water-washing exhaust gas treatment process, in which the gas flow rate of the pre-treated semiconductor exhaust gas entering through the air inlet pipe is 0.1-30 m / s. Under this condition, an appropriate gas flow rate can ensure that the exhaust gas has sufficient residence and contact time with the heating heat, thereby improving the high-temperature decomposition efficiency of harmful exhaust gas, helping to form a stable temperature distribution in the reaction chamber, avoiding local hot spots or cold spots, reducing material damage or corrosion problems caused by uneven temperature, and reducing unnecessary heat loss. At the same time, it can also reduce the power consumption required to drive the gas flow, and also help maintain the continuity and stability of the entire exhaust gas treatment system.

[0025] 4. In the electric heating water-washing tail gas treatment process provided by the present invention, the residence time of the gas in the reaction chamber is 10s to 15min. With the above appropriate residence time, the harmful gas molecules have more opportunities to contact with the high-temperature environment, which helps to improve the completion of the chemical reaction, thereby improving the removal rate of harmful gases.

[0026] 5. The present invention provides an electric heating water washing tail gas treatment process, in which a micro positive pressure is maintained in the reaction chamber for high temperature decomposition of semiconductor tail gas. The purpose of this design is to prevent impurities such as external air or moisture from entering the reaction chamber through loose seals, thereby affecting the tail gas treatment effect and the safe operation of the equipment; for some flammable and explosive semiconductor tail gas components, micro positive pressure helps prevent external air from entering and causing the formation of explosive mixtures; a stable micro positive pressure environment is conducive to controlling and optimizing the flow state and residence time of the tail gas in the reaction chamber, thereby improving the high temperature decomposition efficiency of harmful substances; in the temperature drop area, micro positive pressure can inhibit the premature condensation of some components in the tail gas, ensure the smooth progress of subsequent water washing or separation steps, and improve the tail gas treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, what is described below is only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic diagram of the structure of an electrically heated water-washed semiconductor tail gas treatment device proposed by the present invention;

[0029] Figure 2 It is a schematic diagram of the three-dimensional structure of the reaction chamber of the present invention;

[0030] Figure 3 This is a schematic diagram of the front structure of the reaction chamber of the present invention;

[0031] Figure 4 for Figure 3 AA section view;

[0032] Figure 5 It is a schematic diagram of the water tank structure of the present invention;

[0033] Figure 6 It is a schematic diagram of the front structure of the water tank of the present invention;

[0034] Figure 7 for Figure 6 BB cross-section diagram;

[0035] Figure 8 It is a schematic diagram of the structure of the first water spray pipe of the present invention;

[0036] Fig. 9 It is a schematic diagram of the structure of the second water spray pipe of the present invention;

[0037] Fig.10 It is a schematic diagram of the structure of the third water spray pipe of the present invention;

[0038] Fig.11 It is a schematic diagram of the cooling chamber structure of the present invention;

[0039] Fig.12 yes Fig.11 CC cross-section diagram.

[0040] In the figure, 1-air inlet pipe, 2-main cavity, 3-reaction cavity, 4-cooling cavity, 5-water tank, 6-gas-liquid separation cavity, 301-first cavity layer, 302-second cavity layer, 303-third cavity layer, 401-first air inlet, 402-second air inlet, 403-vortex cavity, 404-cooling outer cavity, 405-cooling inner cavity, 406-first water inlet, 407-second water inlet, 408-spraying port, 409-upper end face, 501-water inlet pipe, 502-first water spraying pipe, 503-second water spraying pipe, 504-third water spraying pipe, 601-first exhaust cavity, 602-second exhaust cavity, 603-acid discharge pipe. DETAILED DESCRIPTION

[0041] In the following description, it should be understood that the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the statement "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same similar parts between the embodiments can be referred to each other. The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used herein to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description herein, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. In this document, unless otherwise specified, the term "plurality" means two or more.

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Embodiment 1:

[0044] like Figure 1 As shown, an electrically heated water-washed semiconductor tail gas treatment equipment comprises an air intake pipe 1, a main cavity 2, a heating rod, a reaction cavity 3, a cooling cavity 4, a water tank 5 and a gas-liquid separation cavity 6, wherein the air intake pipe 1 is connected to the main cavity 2, the heating rod is arranged on the main cavity 2 and extends into the reaction cavity 3, the main cavity 2 is connected to the reaction cavity 3, the lower end of the reaction cavity 3 is connected to the cooling cavity 4, the cooling cavity 4 is connected to the water tank 5, and the water tank 5 is connected to the gas-liquid separation cavity 6; the air intake pipe 1 is provided with a slope of 0.3% to 0.5%; the gas-liquid separation cavity 6 comprises a first exhaust cavity 601, a second exhaust cavity 602 and an acid discharge pipe 603; the first exhaust cavity 601 and the second exhaust cavity 602 are fixedly connected by a flange; the second exhaust cavity 602 and the acid discharge pipe 603 are fixedly connected by a flange.

[0045] The pollutant-containing exhaust gas discharged from the semiconductor production line enters the main cavity 2 through the air intake pipe 1. Preferably, a pre-filter component (not shown in the figure) is provided inside the air intake pipe 1 to preliminarily intercept large particles of dust and some solid impurities. Preferably, the air intake pipe 1 is made of materials with excellent corrosion resistance, high temperature resistance and aging resistance, such as stainless steel or Teflon, etc., to ensure that it is not corroded during long-term contact with the exhaust gas that may contain acidic and alkaline substances and organic solvents. Preferably, a safety device to prevent the backflow of exhaust gas, such as a check valve or a one-way valve, is provided inside the air intake pipe 1 to ensure that the exhaust gas does not flow back and to ensure a safe and stable production environment.

[0046] The inlet pipe 1 is set with a slope of 0.3% to 0.5% to facilitate the discharge of condensed water or solid sediments and prevent gas retention. If the slope of the inlet pipe 1 is lower than 0.3%, the internal environment of the bend of the inlet pipe 1 will be humid, which will accelerate the corrosion of the metal parts of the inlet pipe 1, and may deposit solid particles, increase mechanical wear, and shorten the life of the equipment; if the slope of the inlet pipe 1 is higher than 0.5%, a too steep slope may cause the gas to flow too fast in the pipeline, and thus fail to fully react, reducing the purification efficiency. Preferably, the inlet pipe 1 is set with a slope of 0.4%. The slope of the inlet pipe 1 refers to the ratio between the vertical height difference corresponding to the inclination angle between the axis of the inlet pipe 1 and the horizontal plane and the horizontal projection length. Specifically, the slope of the inlet pipe 1 refers to the rise or fall height per unit length of the pipeline to ensure that the condensed water inside the pipeline can be discharged smoothly without accumulation and blockage, and it is also beneficial to prevent gas flow obstruction. The calculation formula is as follows:

[0047] Slope(i)=(H 1 -H 2 ) / L×100%

[0048] in:

[0049] H 1 is the height of the starting end of the pipe;

[0050] H 2 is the height of the end of the pipe;

[0051] L is the horizontal projection distance from the starting point to the end point of the pipeline.

[0052] The present invention uses electric heating to generate high temperature, which not only has the advantages of strong controllability and fast response speed, but also is cleaner and more efficient than traditional combustion heating. Harmful substances in the tail gas will undergo a series of chemical reactions such as cracking and oxidation after being exposed to high temperature, converting toxic and harmful components into relatively harmless or easy-to-handle forms. After the tail gas is preheated and initially decomposed, its temperature is still high, and further cooling is required to meet the requirements of subsequent processing. Therefore, the tail gas will continue to flow to the cooling chamber 4, where it is cooled by cooling water, air or other cooling media to reduce the tail gas temperature to a safe level. Preferably, cooling is performed by cooling water.

[0053] like Figure 11-12As shown, preferably, the cooling chamber 4 includes a cooling outer cavity 404 and a cooling inner cavity 405, the top of the cooling outer cavity 404 is provided with an upper end surface 409, and there is a gap between the upper end surface 409 and the top of the cooling inner cavity 405; the cooling outer cavity 404 and the cooling inner cavity 405 form a vortex cavity 403 for accommodating cooling water, and the cooling water in the vortex cavity 403 flows down in the form of a water curtain along the inner wall of the cooling inner cavity 405 through the above-mentioned gap. The design of flowing down in the form of a water curtain is, on the one hand, to increase the contact area and contact time between the cooling water and the exhaust gas to be cooled, thereby improving the cooling efficiency; on the other hand, the cooling water can dissolve the water-soluble exhaust gas and flow into the water tank 5.

[0054] Preferably, the cooling outer cavity 404 is provided with a first water inlet 406 and a second water inlet 407, and the vortex cavity 403 is a spiral channel, the first water inlet 406 is provided at the starting point of the spiral channel, and the second water inlet 407 is provided at the end point of the spiral channel. The vortex cavity 403 is designed as a spiral channel, the first water inlet 406 is provided at the starting point of the spiral channel, and as the water flows forward, it continuously contacts the cavity wall and absorbs heat during the spiral rise, the second water inlet 407 is provided at the end point of the spiral channel, and finally flows out from the second water inlet 407 at the end point of the spiral. This design will naturally form a vortex flow, increase the degree of turbulence, and enhance the cooling efficiency. Preferably, the first water inlet 406 and the second water inlet 407 are connected to the water tank 5, and the cooling water in the vortex cavity 403 comes from the water tank 5. Such a design has a good energy-saving effect.

[0055] Preferably, the caliber of the first air inlet 401 is smaller than that of the second air inlet 402. By adjusting the calibers of the first air inlet 401 and the second air inlet 402, the pressure distribution of the exhaust gas is optimized and excessively fast flow of the exhaust gas is prevented, so that the cooling water flowing out of the vortex cavity 403 can be fully in contact with the exhaust gas.

[0056] Preferably, a spray port 408 is provided below the cooling inner cavity 405; the spray port 408 forms an angle of 30° to 60° with the axis of the cooling inner cavity 405. Preferably, the spray port 408 forms an angle of 30° with the axis of the cooling inner cavity 405. The spray port 408 sprays water mist downward, and the spraying in the form of water mist can increase the contact area between the sprayed water mist and the exhaust gas, improve the mass transfer efficiency, and the water mist can directly contact the rising high-temperature exhaust gas, and quickly reduce the exhaust gas temperature through heat exchange, which can not only take away the heat, but also dissolve some harmful gases in the exhaust gas (such as acidic gases, alkaline gases or volatile organic compounds) in water through physical adsorption, chemical reaction, etc., and flow into the water tank 5, thereby achieving the purpose of purifying the exhaust gas.

[0057] Preferably, the gas-liquid separation chamber 6 includes a first exhaust chamber 601, a second exhaust chamber 602 and an acid discharge pipe 603; the first exhaust chamber 601 is fixedly connected to the second exhaust chamber 602 by a flange; the second exhaust chamber 602 is fixedly connected to the acid discharge pipe 603 by a flange. The first exhaust chamber 601 is located at the starting position of the gas-liquid separation process, and its function is to preliminarily separate most of the water from the tail gas after washing with water tank 5. Since the tail gas after washing is mixed with a large number of tiny droplets, these droplets will settle down under the influence of gravity, inertial force and wall effect after entering the first exhaust chamber 601. In order to improve the separation efficiency, the first exhaust chamber 601 usually adopts a water vapor separation structure design, such as a baffle or a cyclone separator, so as to promote full contact and separation of gas and liquid. The second exhaust chamber 602 is provided with a high-efficiency filter fiber mesh to capture smaller droplets and ensure the thoroughness of gas-liquid separation. The gas fully separated by the second exhaust chamber 602 continues to move forward and finally passes through the acid discharge pipe 603. In actual operation, if harmful substances in the tail gas react with water to generate acidic substances, this part of the separated liquid will be safely and properly collected and treated through the acid discharge pipe 603. The material of the acid discharge pipe 603 is selected to have the characteristics of acid corrosion resistance. The acid discharge pipe 603 is made of duplex stainless steel, and its end is connected to a special acid wastewater treatment equipment, such as a neutralization tank or a sedimentation tank, to achieve the purpose of harmless disposal.

[0058] like Figure 2-4As shown, preferably, the reaction chamber 3 is sequentially provided with a first cavity layer 301, a second cavity layer 302 and a third cavity layer 303 from the outside to the inside, and a sealed inner cavity is formed between the first cavity layer 301 and the second cavity layer 302, and the circulating cooling water enters the sealed inner cavity under the action of the circulating pump. Specifically, the first cavity layer 301, the second cavity layer 302 and the third cavity layer 303 have the functions of heat insulation and high temperature resistance, and the third cavity layer 303 has anti-corrosion performance. The three-layer structure of the first cavity layer 301, the second cavity layer 302 and the third cavity layer 303 is conducive to the uniform distribution of heat, and is also conducive to achieving efficient heat insulation effect, avoiding heat loss and overheating of equipment. A closed circulating cooling water inner cavity is formed between the first cavity layer 301 and the second cavity layer 302. In this inner cavity, the circulating pump drives the low-temperature cooling water to flow continuously, and indirectly contacts with the tail gas heated to a high temperature of 600℃ to 1000℃ by the electric heating rod, and performs preliminary heat exchange. The cooling water is used to absorb part of the heat of the exhaust gas, which effectively protects the inner wall surface of the third cavity layer 303 of the reaction chamber 3 from being affected by excessively high temperatures. Preferably, the interior of the third cavity layer 303 is coated with a high temperature resistant and corrosion resistant material. The inner wall of the third cavity layer 303 is coated with a ceramic coating, which is a zirconium oxide, silicon nitride or silicon carbide coating, preferably a silicon carbide coating, which has excellent oxidation resistance, corrosion resistance and wear resistance, and has excellent chemical stability, and can remain stable in an environment of up to 1000°C or above.

[0059] like Figure 5-10 As shown, preferably, the water tank 5 is provided with a water inlet pipe 501, a first water spray pipe 502, a second water spray pipe 503 and a third water spray pipe 504, and the water inlet pipe 501 is respectively connected with the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504. The water inlet pipe 501 serves as a water source access point to introduce clean circulating water or fresh water into the water tank 5, and further distributes it to the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504.

[0060] Preferably, the first water spray pipe 502 and the third water spray pipe 504 are arranged horizontally and perpendicular to each other; the second water spray pipe 503 and the third water spray pipe 504 are arranged horizontally and perpendicular to each other. The first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504 form a complementary coverage range in space. On the one hand, such a layout can also effectively avoid the spray overlap and energy waste caused by the close distance between the water spray pipes, and ensure that the independent function of each water spray pipe can be fully exerted; on the other hand, the mutually perpendicular design is also conducive to the generation of turbulence and mixing effects during the water washing process, promotes the full mixing between gas and liquid, maximizes the gas-liquid contact area, and enhances the speed and degree of chemical reaction. In this way, the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504 are in the same plane, forming a three-dimensional cross-spraying network. Such a three-dimensional layout ensures that the exhaust gas can contact the spray water in all directions and at multiple angles after entering the water tank 5, thereby increasing the contact area between the gas and the water, thereby improving the speed and effect of the dissolution or chemical reaction of harmful substances.

[0061] Preferably, the heights of the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504 are lower than the upper cover plate of the water tank 5. Such a design is conducive to the exhaust gas fully contacting with the sprayed water droplets during the rising process, and is also conducive to preventing the high-speed sprayed water mist from escaping the water tank 5, causing water resource waste and environmental impact.

[0062] Preferably, a plurality of nozzles are provided on the first water spray pipe 502 , the second water spray pipe 503 and the third water spray pipe 504 .

[0063] Preferably, the first water spray pipe 502 and the third water spray pipe 504 are provided with a plurality of one-way nozzles, preferably, the number of the one-way nozzles is two or three, and the one-way nozzles have the characteristics of strong directionality and strong impact force, and can effectively decompose water into fine water mist, thereby enhancing the effect of mixing with the exhaust gas. The second water spray pipe 503 is provided with a plurality of two-way nozzles, preferably, the number of the two-way nozzles is two, and the two-way nozzles can not only spray to the left, but also spray to the right, forming a left-right staggered spray array, so that the exhaust gas after high-temperature decomposition can be uniformly and comprehensively washed by water no matter from which direction it enters the water tank 5.

[0064] Embodiment 2:

[0065] An electric heating water washing tail gas treatment process comprises the following steps:

[0066] S1. High-temperature decomposition of tail gas: pre-treated semiconductor tail gas enters through the air inlet pipe 1, then enters the main cavity 2, and finally enters the reaction cavity 3. The heating rod in the reaction cavity 3 electrically heats the tail gas for high-temperature decomposition. The reaction cavity 3 is sequentially provided with a first cavity layer 301, a second cavity layer 302 and a third cavity layer 303 from the outside to the inside. A sealed inner cavity is formed between the first cavity layer 301 and the second cavity layer 302. Circulating cooling water enters the sealed inner cavity under the action of a circulating pump. After being cooled by the circulating cooling water, the tail gas enters the cooling cavity 4 and then flows into the water tank 5. Preferably, the temperature in step S1 is 600°C to 1000°C.

[0067] Preferably, the gas flow rate of the pre-treated semiconductor tail gas entering through the air inlet pipe 1 is 0.1-30m / s. Under this condition, the appropriate gas flow rate can ensure that the tail gas has sufficient residence and contact time with the heating heat, thereby improving the high-temperature decomposition efficiency of the harmful tail gas, helping to form a stable temperature distribution in the reaction chamber 3, avoiding local hot spots or cold spots, reducing material damage or corrosion problems caused by uneven temperature, and reducing unnecessary heat loss. At the same time, it can also reduce the power consumption required for driving gas flow, and also help maintain the continuity and stability of the entire tail gas treatment system. If the flow rate is too fast, exceeding 30m / s, it will cause the gas to pass through the reaction area quickly without completing a full reaction. In addition, the high-speed flow of gas may cause erosion corrosion and aggravate equipment wear; on the contrary, if the flow rate is too slow, less than 0.1m / s, it may cause low heat utilization and affect the processing efficiency. In addition, for the tail gas after high-temperature treatment, the gas flow rate is controlled. When the tail gas enters the cooling chamber 4, it can effectively prevent the gas from cooling too fast to produce condensation, and ensure the smooth progress of the subsequent water washing or water vapor separation steps. More preferably, the gas flow rate of the pre-treated semiconductor tail gas entering through the air inlet pipe 1 is 20 m / s.

[0068] Preferably, the residence time of the gas in the reaction chamber 3 is 10s to 15min. If the residence time is less than 5s, some harmful substances may leave the reaction chamber 3 without being completely decomposed, generating new harmful gases; if the residence time is more than 15min, energy consumption will increase. Therefore, with the above appropriate residence time, the harmful gas molecules have more opportunities to contact the high temperature environment, which helps to improve the completion of the chemical reaction, thereby improving the removal rate of harmful gases. Preferably, the residence time of the gas in the reaction chamber 3 is 10min. More preferably, the residence time of the gas in the reaction chamber 3 is 8min.

[0069] Preferably, in the reaction chamber 3 for high-temperature decomposition of semiconductor tail gas, a micro-positive pressure is maintained in the reaction chamber 3. In the present invention, micro-positive pressure means that the pressure in the reaction chamber 3 is slightly higher than the external atmospheric pressure, and the micro-positive pressure is 0.1-0.5 bar. The purpose of this design is to prevent impurities such as external air or moisture from entering the reaction chamber 3 through the poorly sealed areas, thereby affecting the tail gas treatment effect and the safe operation of the equipment; for some flammable and explosive semiconductor tail gas components, micro-positive pressure helps prevent external air from entering and causing the formation of explosive mixtures; a stable micro-positive pressure environment is conducive to controlling and optimizing the flow state and residence time of the tail gas in the reaction chamber, thereby improving the high-temperature decomposition efficiency of harmful substances; in the temperature drop area, the micro-positive pressure can inhibit the premature condensation of some components in the tail gas, ensuring the smooth progress of the subsequent washing or separation steps. Preferably, the micro-positive pressure is 0.3 bar.

[0070] Specifically, the first cavity layer 301, the second cavity layer 302 and the third cavity layer 303 have the functions of heat insulation and high temperature resistance, and the third cavity layer 303 has anti-corrosion performance. The three-layer structure of the first cavity layer 301, the second cavity layer 302 and the third cavity layer 303 is conducive to the uniform distribution of heat, and is also conducive to achieving efficient heat insulation effect, avoiding heat loss and equipment overheating. A closed circulating cooling water cavity is formed between the first cavity layer 301 and the second cavity layer 302. In this cavity, the circulating pump drives the low-temperature cooling water to flow continuously, and indirectly contacts the tail gas heated to 600℃~1000℃ by the electric heating rod to perform preliminary heat exchange. Using cooling water to absorb part of the heat of the tail gas, on the one hand, it ensures that the tail gas can quickly reach the high temperature conditions suitable for decomposition, and on the other hand, it effectively protects the wall of the reaction chamber 3 from being affected by excessive temperature. The inner wall of the third cavity layer 303 is coated with a ceramic coating, which is a zirconium oxide, silicon nitride or silicon carbide coating, preferably a silicon carbide coating, which has excellent oxidation resistance, corrosion resistance and wear resistance, and has excellent chemical stability and can remain stable in an environment as high as 1000°C.

[0071] The present invention uses electric heating to generate high temperature, which not only provides the advantages of strong controllability and fast response speed, but also is cleaner and more efficient than traditional combustion heating. Harmful substances in the exhaust gas will undergo a series of chemical reactions such as cracking and oxidation after being exposed to high temperature, converting toxic and harmful components into relatively harmless or easy-to-handle forms. After the exhaust gas is preheated and preliminarily decomposed, its temperature is still high, and further cooling is required to meet the requirements of subsequent processing. Therefore, the exhaust gas will continue to flow to the cooling chamber 4, where it is cooled by air or other cooling media to reduce the exhaust gas temperature to a safe level.

[0072] S2. Tail gas washing: The tail gas decomposed by high temperature enters the water tank 5 through the cooling chamber 4, and the tail gas contacts the water in the water tank 5 to treat harmful gases that can be dissolved by water or undergo chemical reactions to generate soluble salts.

[0073] Preferably, the water tank 5 is provided with a water inlet pipe 501, a first water spray pipe 502, a second water spray pipe 503 and a third water spray pipe 504, and the water inlet pipe 501 is respectively connected with the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504. The water inlet pipe 501 serves as a water source access point to introduce clean circulating water or fresh water into the water tank 5, and further distributes it to the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504.

[0074] Preferably, the first water spray pipe 502 and the third water spray pipe 504 are arranged horizontally and perpendicular to each other; the second water spray pipe 503 and the third water spray pipe 504 are arranged horizontally and perpendicular to each other; the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504 are arranged horizontally and perpendicular to each other; the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504 are in the same plane, forming a three-dimensional cross-spraying network. Such a three-dimensional layout ensures that the exhaust gas can be in full contact with the spraying water after entering the water tank 5, increasing the contact area between the gas and the water, thereby improving the speed and effect of the dissolution or chemical reaction of harmful substances.

[0075] Preferably, the heights of the first water spray pipe 502, the second water spray pipe 503 and the third water spray pipe 504 are lower than the upper cover plate of the water tank 5. Such a design is conducive to the exhaust gas fully contacting with the sprayed water droplets during the rising process, and is also conducive to preventing the high-speed sprayed water mist from escaping the water tank 5, causing water resource waste and environmental impact.

[0076] Preferably, a plurality of nozzles are provided on the first water spray pipe 502 , the second water spray pipe 503 and the third water spray pipe 504 .

[0077] Preferably, the first water spray pipe 502 and the third water spray pipe 504 are provided with a plurality of one-way nozzles, preferably, the number of the one-way nozzles is two or three, the one-way nozzles have the characteristics of strong directionality and strong impact, and can effectively decompose water into fine water mist, enhancing the effect of its mixing with the exhaust gas. The second water spray pipe 503 is provided with a plurality of two-way nozzles, preferably, the number of the two-way nozzles is two, the two-way nozzles can not only spray to the left, but also spray to the right, forming a left-right staggered spray array, so that the exhaust gas after high-temperature decomposition can be evenly and comprehensively washed by water no matter from which direction it enters the water tank.

[0078] S3. Water vapor separation of tail gas: After water washing, the tail gas passes through the gas-liquid separation chamber 6 for water vapor separation. The gas-liquid separation chamber 6 includes a first exhaust chamber 601, a second exhaust chamber 602 and an acid discharge pipe 603; the first exhaust chamber 601 is fixedly connected to the second exhaust chamber 602 through a flange; the second exhaust chamber 602 is fixedly connected to the acid discharge pipe 603 through a flange.

[0079] The first exhaust chamber 601 is located at the starting position of the gas-liquid separation process, and its main function is to preliminarily separate most of the water from the tail gas after washing with water tank 5. Since the tail gas after washing is mixed with a large number of tiny droplets, these droplets will settle down under the influence of gravity, inertial force and wall effect after entering the first exhaust chamber 601. In order to improve the separation efficiency, the first exhaust chamber 601 usually adopts a specific streamlined structure design, such as baffles or cyclone separators, so as to promote the full contact and separation of gas and liquid. The second exhaust chamber 602 is equipped with a high-efficiency filter fiber screen to capture more tiny droplets to ensure the thoroughness of gas-liquid separation. The gas fully separated by the second exhaust chamber 602 continues to move forward and is finally discharged through the acid discharge pipe 603. Because in the actual operation process, if the harmful substances in the tail gas react with water to generate acidic substances, this part of the separated liquid will be safely and properly collected and processed through the acid discharge pipe 603. The material selection of the acid discharge pipe 603 has the characteristics of corrosion resistance. The acid discharge pipe 603 is made of duplex stainless steel, and its end is connected to a special acid wastewater treatment equipment, such as a neutralization tank or a sedimentation tank, to achieve the purpose of harmless disposal.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electrically heated water-washed semiconductor tail gas treatment device, characterized in that: The invention comprises an air intake pipe (1), a main cavity (2), a heating rod, a reaction cavity (3), a cooling cavity (4), a water tank (5) and a gas-liquid separation cavity (6), wherein the air intake pipe (1) is connected to the main cavity (2), the heating rod is arranged on the main cavity (2) and extends into the reaction cavity (3), the main cavity (2) is connected to the reaction cavity (3), the lower end of the reaction cavity (3) is connected to the cooling cavity (4), the cooling cavity (4) is connected to the water tank (5), and the water tank (5) is connected to the gas-liquid separation cavity (6); the air intake pipe (1) is provided with a slope of 0.3% to 0.5%; the gas-liquid separation cavity (6) comprises a first exhaust cavity (601), a second exhaust cavity (602) and an acid discharge pipe (603); the first exhaust cavity (601) and the second exhaust cavity (602) are fixedly connected by a flange; the second exhaust cavity (602) and the acid discharge pipe (603) are fixedly connected by a flange.

2. The electrically heated water-washed semiconductor tail gas treatment equipment according to claim 1, characterized in that: The reaction chamber (3) is provided with a first cavity layer (301), a second cavity layer (302) and a third cavity layer (303) in sequence from the outside to the inside, a sealed inner cavity is formed between the first cavity layer (301) and the second cavity layer (302), and circulating cooling water enters the sealed inner cavity under the action of a circulating pump.

3. The electrically heated water-washed semiconductor tail gas treatment equipment according to claim 2 is characterized in that: The interior of the third cavity layer (303) is coated with a high temperature resistant and corrosion resistant material.

4. The electrically heated water-washed semiconductor tail gas treatment equipment according to claim 3 is characterized in that: The water tank (5) is provided with a water inlet pipe (501), a first water spray pipe (502), a second water spray pipe (503) and a third water spray pipe (504); the water inlet pipe (501) is respectively connected to the first water spray pipe (502), the second water spray pipe (503) and the third water spray pipe (504).

5. The electrically heated water-washed semiconductor tail gas treatment equipment according to claim 4 is characterized in that: The first water spray pipe (502) and the third water spray pipe (504) are arranged horizontally and perpendicular to each other; the second water spray pipe (503) and the third water spray pipe (504) are arranged horizontally and perpendicular to each other; the first water spray pipe (502), the second water spray pipe (503) and the third water spray pipe (504) are in the same plane.

6. The electrically heated water-washed semiconductor tail gas treatment equipment according to claim 4, characterized in that: The heights of the first water spray pipe (502), the second water spray pipe (503) and the third water spray pipe (504) are lower than the upper cover plate of the water tank (5).

7. The electrically heated water-washed semiconductor tail gas treatment equipment according to claim 6, characterized in that: The first water spray pipe (502), the second water spray pipe (503) and the third water spray pipe (504) are provided with a plurality of nozzles.

8. An electric heating water washing tail gas treatment process, characterized in that: The use of the electrically heated water-washed tail gas treatment equipment according to claims 1 to 7 comprises the following steps: S1. High-temperature decomposition of tail gas: the pre-treated semiconductor tail gas enters through the air inlet pipe (1), then enters the main cavity (2), and finally enters the reaction cavity (3). The heating rod in the reaction cavity (3) electrically heats the tail gas for high-temperature decomposition. The reaction cavity (3) is provided with a first cavity layer (301), a second cavity layer (302), and a third cavity layer (303) from the outside to the inside. A sealed inner cavity is formed between the first cavity layer (301) and the second cavity layer (302). Circulating cooling water enters the sealed inner cavity under the action of a circulating pump. The tail gas enters the cooling cavity (4) after being cooled by the circulating cooling water, and then flows into the water tank (5); S2. Washing of tail gas: The tail gas decomposed by high temperature enters the water tank (5) through the cooling chamber (4), and the tail gas contacts the water in the water tank (5) to treat harmful gases that can be dissolved by water or undergo chemical reactions to generate soluble salts; S3. Water vapor separation of tail gas: The tail gas after water washing passes through the gas-liquid separation chamber (6) for water vapor separation.

9. The electrically heated water-washing tail gas treatment process according to claim 8 is characterized in that: The temperature in step S1 is 600°C to 1000°C.

10. The electric heating water washing tail gas treatment process according to claim 8, characterized in that: The gas flow rate of the pre-treated semiconductor tail gas entering through the air inlet pipe 1 is 0.1-30 m / s.

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