Circulating water tank for tail gas treatment

Abstract

The utility model provides a circulating water tank for tail gas treatment. The circulating water tank comprises a tank body, a cooling water inlet, a circulating water outlet, a circulating water pump, a circulating water inlet, a gas inlet and a gas outlet, a liquid level monitoring device and a temperature monitoring device are arranged in the box body, and the liquid level monitoring device comprises five groups of liquid level sensors; the liquid level monitoring device and the temperature monitoring device control water feeding and water discharging of the box body through a controller. Water feeding and water discharging of the water tank are jointly controlled through the five sets of liquid level sensors and the temperature sensor, and the water consumption can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tail gas treatment, in particular to a circulating water tank for tail gas treatment. BACKGROUND

[0002] In the process of producing semiconductor, photovoltaic and other devices, a large amount of chemical substances and process gases will be used and generated. The tail gas treatment process is usually carried out by professional tail gas treatment equipment. The tail gas treatment equipment can provide excellent gas treatment capacity and convenient and safe plant front-end operation. The tail gas treatment equipment is suitable for semiconductor manufacturing processes including CVD (chemical vapor deposition), Diffusion (diffusion), Etch (etching), Ion implantation (ion implantation) and other processes, which can safely and effectively treat fluorine-containing, chlorine-containing, hydrogen-containing and most toxic, flammable, explosive and corrosive production process gases to prevent personal and production hazards and further prevent air pollution. It is suitable for semiconductor process gases such as SiH4, PH3, AsH3, B2H6, NH3, WF6 and the like.

[0003] The tail gas treatment equipment is usually directly connected with the exhaust port of the process equipment, and usually includes a high-temperature treatment structure and a cooling and dust removal structure. The high-temperature treatment structure includes a combustion type, a plasma ionization type and an electric heating type, and the subsequent cooling and dust removal structure is generally realized by a water washing treatment equipment.

[0004] However, in the existing water washing treatment equipment, the structure and function are relatively simple and single, and there are problems such as poor cooling effect, large water consumption, lack of temperature signal support, and easy to produce blockage, so that the maintenance frequency and use cost of the water washing treatment equipment are too high.

[0005] In order to solve the above problems, the present application provides a circulating water tank for tail gas treatment, which can effectively improve the treatment efficiency, reduce the water consumption and the maintenance frequency.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of clearly and completely describing the technical scheme of the present application, and for the convenience of understanding by those skilled in the art. The above technical scheme cannot be considered as known to those skilled in the art only because it is described in the background section of the present application. CONTENT OF THE INVENTION

[0007] The present application provides a circulating water tank for tail gas treatment to effectively improve the treatment efficiency of the water tank, reduce the water consumption and the maintenance frequency.

[0008] In order to achieve the above object, the utility model provides a kind of circulating water tank for tail gas treatment, comprising: tank, cooling water import, circulating water outlet, circulating water pump, air inlet and air outlet;Liquid level monitoring device and temperature monitoring device are arranged in the tank, the liquid level monitoring device includes 5 groups of liquid level sensors;The liquid level monitoring device and the temperature monitoring device control the water inlet and drainage of the tank by controller.It can effectively reduce water consumption by 5 groups of liquid level sensors and one temperature sensor jointly control the water inlet and drainage of water tank.

[0009] In some embodiments, the liquid level monitoring device is arranged on the inner wall of one side of the tank, and the liquid level monitoring device includes a high alarm sensor from top to bottom, a water filling stop sensor, a working liquid level sensor, a drainage stop sensor and a low alarm sensor.

[0010] In some embodiments, the temperature monitoring device is arranged close to the circulating water outlet, and is located below the height of the low alarm sensor. This arrangement can measure the water temperature after circulation as much as possible.

[0011] In some embodiments, the cooling water import is arranged on one side of the tank, and the circulating water outlet is arranged on the other side of the tank, and the circulating water outlet is communicated with the circulating water pump; the air inlet and the air outlet are arranged on both sides of the top plate of the tank.

[0012] In some embodiments, a plurality of circulating water imports are arranged in the tank, one end of the circulating water import is communicated with the circulating water pump through a circulating pipeline, and the other end of the circulating water import is connected with a spray port. By circulating water, water can be saved, and by multiple spray ports, the internal space of the water tank can be covered as much as possible, improving the cooling and dust removal efficiency for tail gas.

[0013] In some embodiments, a plurality of circulating water imports are evenly distributed in the tank, each circulating water import is communicated with a plurality of spray ports through a pipeline, and the spray port is sleeved with an atomizing nozzle. The use of atomizing nozzle can further increase the contact area with tail gas and improve the processing efficiency.

[0014] In some embodiments, the circulating water import is arranged in the air inlet, and the spray port is communicated with the circulating water import, and the spray port is sleeved with an atomizing nozzle; a circulating water import is arranged below the air outlet, and the spray port is communicated with the circulating water import. By arranging a circulating cooling pipeline near the air inlet and the air outlet, the high-temperature tail gas discharged can be quickly cooled and dusted, and the service life of the water tank can also be increased.

[0015] In some embodiments, a plurality of partitions are arranged in the box, the partitions are solid partitions, and lower ends of the partitions are fixedly connected to the bottom of the box; the partitions are arranged on the side close to the air inlet, the partitions are arranged at intervals, and heights of the partitions gradually decrease along the direction from the air inlet to the air outlet. The partitions can separate the fused water and the clean water, a large amount of dust can be filtered and deposited in the water tank and solved by simple cleaning, waste liquid blockage and maintenance of the water pipe are avoided.

[0016] In some embodiments, a condensation particle baffle is arranged transversely in the box. The falling circulating water mist can be condensed and collected at the bottom of the water tank.

[0017] In some embodiments, a detachable observation window is arranged on the front of the box, and the observation window is made of transparent material. The inside of the process water tank can be conveniently observed, and the dust can be quickly cleaned through the observation window.

[0018] Compared with the prior art, the main beneficial effects of the utility model are as follows: 1) the tail gas can be effectively cooled, the exhaust pressure of the plant is reduced, and the service life of the cavity is prolonged; 2) the efficiency of treating the tail gas is improved, and the amount of dust in the tail gas is reduced; 3) the amount of water used is greatly reduced, the water is greatly saved, the amount of drainage is reduced, and the amount of plant treatment is reduced; 4) a large amount of dust can be filtered and deposited in the water tank, waste liquid blockage, maintenance of the water pipe and other problems are avoided, and the pressure of treating the waste water of the plant is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the specific embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings described below are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating creative labor.

[0020] Figure 1 It is a circulating water tank schematic diagram of embodiment one. DETAILED DESCRIPTION

[0021] The foregoing and other technical contents, characteristics and effects of the utility model will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. The direction terms mentioned in the following embodiments, such as up, down, left, right, front or back, are only the directions of the drawings. Therefore, the direction terms are used to illustrate and not to limit the utility model.

[0022] Embodiment one:

[0023] The tail gas treatment technology can be a combustion type tail gas treatment technology, a plasma type tail gas treatment technology, an electric heating type tail gas treatment technology, etc. For example, in the semiconductor technology, when treating process tail gas such as SiH4, PH3, AsH3, B2H6, NH3, WF6, etc., the electric heating water washing method is usually used for treatment, that is, the tail gas is preheated by instant heating (more than 800 DEG C) through a heating rod and then discharged into a water washing device, so that the harmful components or generated particulate matters are more easily captured and adsorbed by water. Subsequently, the preheated tail gas is contacted with water through a spraying system, and the generated matters are dissolved under high temperature conditions. After water washing, most of the harmful components are ensured to be left in the water, and the clean gas can be discharged. The water tank is a device system for cooling and dust removal of the tail gas. The present application aims to provide a circulating water tank for tail gas treatment.

[0024] Figure 1 A schematic view of a circulating water tank for tail gas treatment is provided for Embodiment One. As shown in the figure, a circulating water tank for tail gas treatment comprises a tank body 1, a cooling water inlet 2, a circulating water outlet 3, a circulating water pump 4, a circulating water inlet 5, an air inlet 6, and an air outlet 7. Figure 1

[0025] As shown in the figure, the cooling water inlet 2 is arranged on one side of the tank body 1, and the cooling water inlet 2 is used as a fresh water source access point to introduce fresh cooling water into the tank body 1. The circulating water outlet 3 is arranged on the other side of the tank body 1, and is generally arranged below the side plate of the tank body 1, so that the liquid in the tank body 1 can flow into the circulating water pump 4 through the circulating water outlet 3. Figure 1

[0026] The circulating water pump 4 in the present embodiment is arranged outside the side of the tank body 1, and is responsible for pumping the liquid in the tank body 1 out and delivering it to the circulating water inlets 5 through the circulating pipeline according to the actual situation or directly discharging the waste liquid. It can be understood that the suction end of the circulating water pump 4 is connected to the circulating water outlet 3, so as to pump the liquid in the tank body 1 out. In the present embodiment, the three-way valve 9 is used to realize the two functions of circulating cooling water and discharging waste liquid, that is, the discharge end of the circulating water pump 4 is connected to the input port of the three-way valve 9, one of the two output ports of the three-way valve 9 is connected to the drain port to discharge the waste liquid, and the other output port of the three-way valve 9 is connected to the circulating pipeline to realize the circulation of water. In other embodiments, the liquid pumped out by the circulating water pump 4 includes at least two output ports, at least one of which is connected to the drain port for discharging waste liquid; similarly, at least one port is also connected to the circulating pipeline, and the circulating pipeline can further distribute the circulating water according to the number of circulating water inlets 5, that is, for delivering the liquid in the tank body 1 to each circulating water inlet 5 to realize the recycling of the cooling water. In other embodiments, the number of ports connected to the waste liquid discharge pipeline and the circulating pipeline can be designed according to the actual situation.​​

[0027] The circulating water inlets 5 are provided in plurality, and are communicated with the circulating water pump 4 through respective circulating pipelines, and further communicated with the tank 1, that is, the cooling water of the circulating water inlets 5 is from the tank 1; one circulating water pump 4 is adopted to carry out water circulation and sewage discharge, so that the system structure is simple, the cost can be reduced, the energy consumption can be reduced, and the water resource can be saved.

[0028] As shown in Figure 1 , the air inlet 6 is communicated with the tank 1, and the circulating water inlets 5 are arranged in the air inlet 6, through which the input high-temperature tail gas can be rapidly cooled, and the water tank life is increased; similarly, the air outlet 7 is also communicated with the tank 1, and the circulating water inlets 5 are also arranged below the air outlet 7. The circulating water of the air inlet 6 and the air outlet 7 will finally flow into the tank 1 and circulate. The air inlet 6 and the air outlet 7 are arranged as a conventional arrangement in the art, in order to ensure the sealing of the connection between the tank 1 and the air inlet 6 and the connection between the tank 1 and the air outlet 7, sealing rings or threaded seals are used at the connection, which are not limited specifically. The air inlet 6 and the air outlet 7 are generally arranged on the top plate of the tank 1, and are arranged on the two sides of the top plate respectively, so that the tail gas can flow in the internal space of the tank 1 as much as possible, and the contact time of the tail gas and the water mist is increased, but not limited specifically.

[0029] As shown in Figure 1 , in addition to the circulating water inlets 5 arranged at the air inlet 6 and the air outlet 7, a plurality of circulating water inlets 5 are also arranged in the tank 1, and in order to ensure the cooling efficiency and dust removal efficiency of the tail gas, the spray openings 51 are connected outside the circulating water inlets 5; the spray openings 51 are used to increase the contact area of the water and the tail gas by spraying water, so as to achieve the effects of efficiently cooling the tail gas, decomposing the gas soluble in water and removing dust.

[0030] Specifically, the spray openings 51 are connected to each of the circulating water inlets 5 (not all shown in the figure, and the spray openings 51 are also connected to the air inlet 6 and the air outlet 7); the spray openings 51 are communicated with the respective circulating water inlets 5 through pipelines, and each circulating water inlet 5 can be correspondingly communicated with a plurality of spray openings 51, as shown in Figure 1The spray nozzles 51 are arranged in the tank 1 and can spray water mist upward / downward. The spray in the form of water mist can increase the contact area between the water mist and the tail gas, improve the mass transfer efficiency, and directly contact the high-temperature tail gas discharged, rapidly reduce the temperature of the tail gas through heat exchange, not only remove heat, but also dissolve part of harmful gases (such as acid gas, alkaline gas or volatile organic compounds) in the tail gas in water through physical adsorption, chemical reaction and the like, and finally flow into the lower part of the tank 1, so as to achieve the purpose of purifying the tail gas. In order to ensure that the circulating cooling water covers the inside of the tank 1 comprehensively, a plurality of circulating water inlets 5 are uniformly distributed in the upper space inside the tank 1, and the circulating water inlets 5 are also arranged above the tank 1 to make up for the atomization coverage in the water tank.

[0031] The spray nozzles 51 are arranged in the tank 1 and can spray water mist upward / downward. The spray in the form of water mist can increase the contact area between the water mist and the tail gas, improve the mass transfer efficiency, and directly contact the high-temperature tail gas discharged, rapidly reduce the temperature of the tail gas through heat exchange, not only remove heat, but also dissolve part of harmful gases (such as acid gas, alkaline gas or volatile organic compounds) in the tail gas in water through physical adsorption, chemical reaction and the like, and finally flow into the lower part of the tank 1, so as to achieve the purpose of purifying the tail gas. In order to ensure that the circulating cooling water covers the inside of the tank 1 comprehensively, a plurality of circulating water inlets 5 are uniformly distributed in the upper space inside the tank 1, and the circulating water inlets 5 are also arranged above the tank 1 to make up for the atomization coverage in the water tank.

[0032] The spray nozzles 51 can adopt a direct injection form, or can be atomized through a hole, that is, an atomizing nozzle (not shown in the figure) is sleeved outside the spray nozzles 51, to further ensure the efficiency. In the embodiment, the spray nozzles 51 arranged at the gas outlet 7 can not be provided with an atomizing nozzle. In the embodiment, a one-way nozzle is adopted for the atomizing nozzle. The one-way nozzle has the characteristics of strong directivity and large impact force, and can effectively decompose water into fine water mist, thereby enhancing the mixing effect with the tail gas. In other embodiments, a multi-way nozzle can also be selected.

[0033] The liquid level monitoring device 11 can monitor the position of the liquid surface in the box 1 in real time, and the temperature monitoring device 12 can be used to monitor the real-time temperature in the box 1 in real time. The liquid level monitoring device 11 is arranged on the side wall of one side of the box 1, and includes five groups of liquid level sensors, from top to bottom, high alarm sensor 111, water injection stop sensor 112, working liquid level sensor 113, drainage stop sensor 114 and low alarm sensor 115. In this embodiment, the liquid level sensor used is a photosensitive liquid level sensor. The temperature monitoring device 12 is located as close as possible to the position of the circulating water outlet 3 of the box 1, and is located below the liquid level and below the height of the low alarm sensor 115, so as to accurately measure the temperature of the water after circulation and avoid measuring the temperature of the air. In this embodiment, the temperature sensor used is a thermocouple. The above liquid level monitoring device 11 and temperature monitoring device 12 are respectively connected with the valves at the cooling water inlet 2 and the circulating water outlet 3 through the controller, and the water amount control of the box 1 (i.e. the water inlet and drainage of the box 1) is realized according to the signal.

[0034] The box 1 is also provided with a baffle 13. The baffles 13 are arranged in the box 1 at intervals. The lower end of the baffle 13 is fixedly connected with the bottom of the box 1. The baffle 13 is designed according to the size of the water tank. In this embodiment, the baffle 13 has three, which occupies one side of the box 1 close to the air inlet 6, and is arranged in turn in the direction from the air inlet 6 to the air outlet 7, and the highest baffle 13 is slightly lower than the liquid level. The spacing between the baffles 13 is uniformly arranged. The material of the baffle 13 is corrosion-resistant and high-temperature-resistant material, which can also be the same material as the box 1, and the baffle 13 is a solid baffle. The baffle 13 can separate the fusion water and the clean water by partitioning, that is, after the exhaust gas is washed by water, the dust 8 is dissolved into the water and circulates to the lower space of the box 1 by gravity, and is filtered and deposited in the box 1. It can be understood that the dust 8 near the air inlet 6 is more, and the dust 8 finally deposited on this side is also more, which separates the fusion water (more dust 8 deposition) and the clean water (less dust 8 deposition). It can be understood that in order to ensure the working effect of the circulating water tank, the circulating water outlet 3 should be arranged in the area away from the baffle 13, that is, in the lower part of the side close to the air outlet of the box 1. Because this area is a clean water area, the water washing efficiency can be improved when the liquid is pumped in this area for subsequent circulation, and the dust content of the waste liquid can be reduced when the liquid is drained, reducing the possibility of blockage of the waste liquid pipeline and the difficulty of waste liquid treatment. By arranging the baffle 13, a large amount of dust 8 is filtered and deposited on the left side of the box 1, and the deposited dust 8 can be cleaned by simple single maintenance (time about 10 min), which can clean at least 80% of the dust, avoid causing waste liquid blockage, maintenance water pipe and other problems, and reduce the pressure of factory waste water treatment.

[0035] In the box 1 is also transversely provided with condensing particle baffle 14, when the high temperature exhaust gas after the discharge, with the spray water mist neutralization, when the exhaust gas through the spray water mist washing, sewage by gravity to the condensing particle baffle 14 and in the condensation after the recycling in the box 1, save water resources. As shown in Figure 1 The setting position of the condensing particle baffle 14 is slightly higher than the installation height of the working liquid level sensor 113.

[0036] The front of the box 1 is provided with an observation window (not shown in the figure). The observation window is made of transparent material, which is convenient for the staff to observe the internal situation of the box 1, so as to take timely measures. The observation window can also be opened and easily removed, and the dust 8 can be removed through it.

[0037] In use, the high temperature exhaust gas enters the inside of the box 1 from the air inlet 6. At this time, the three-dimensional spray water mist is formed in the box 1 by the multiple circulating water inlets 5 and the spray ports 51 in the inside, which cools and dedusts the exhaust gas. The water washed exhaust gas is discharged from the air outlet 7 to the subsequent plant for treatment; the sprayed water mist will take the heat and dust 8 in the exhaust gas and fall into the lower part of the box 1 under the action of gravity, and be recycled under the action of the circulating water pump 4. In this process, the dust 8 is separated by the partition plate 13, so that most of the dust 8 is deposited in the box 1 and cleaned later.

[0038] The liquid level monitoring device 11 and the temperature monitoring device 12 are arranged in the box body 1, and are connected with valves at the cooling water inlet 2 and the circulating water outlet 3 through controllers, so that the water inlet and water outlet control of the box body 1 can be realized according to the combined conditions of the liquid level height and the temperature of the circulating water in the box body 1. Specifically, when starting, the water tank starts to fill water until the liquid level reaches the water filling stop sensor 112, then starts to drain water until the working liquid level sensor 113, and then the circulating water tank starts to work and uses the water in the box body 1 for recycling; subsequently, with tail gas treatment, when the liquid level drops to the water draining stop sensor 114 due to evaporation, the water inlet starts, and the water inlet stops when the liquid level reaches the water filling stop sensor 112, and then the water outlet starts to drain water until the working liquid level sensor 113, so that the recycling work starts; in addition to the liquid level height, temperature control is also added, for example, the safety temperature is set to 45 DEG C, when the temperature monitoring device 12 finds that the temperature of the circulating water exceeds 45 DEG C, the water inlet operation is started to neutralize and reduce the temperature, that is, the cooling water is injected until the liquid level reaches the water filling stop sensor 112, then the water outlet starts to drain water until the working liquid level sensor 113, the temperature of the water tank is judged again, and the water filling and water draining process continues until the temperature meets the requirement, and the water tank works. If the water level of the box body 1 reaches the high alarm sensor 111 or the low alarm sensor 115, the system alarms; in addition, an upper limit value of the temperature can be set, and when the temperature reaches the upper limit value, the work of the process machine connected to the circulating water tank is stopped to protect the machine. Through the above alternating circulation, the accumulation of excessive by-products in the box body 1 can be prevented, and the temperature of the water tank can be prevented from being too high, which is beneficial to ensure the safety of the equipment during operation, greatly saves the water consumption, improves the equipment utilization rate, and prolongs the service life of the equipment.

[0039] Generally, the large maintenance period is 3 months, through the design scheme, single small maintenance (about 10 min) simple cleaning can be adopted, large dust can be cleaned, at least 80% of dust can be cleaned, and the large maintenance period can be prolonged to 4-6 months, so that the drainage pressure and the blockage problem are reduced. The embodiment is described by taking the water tank for semiconductor tail gas treatment, and the device is also suitable for treatment of other special gases and tail gases, such as solar energy and photovoltaic equipment, so that the treatment efficiency can be effectively improved, the waste water and waste gas discharge amount can be reduced, and the cost expenditure can be reduced.

[0040] Some common English nouns or letters used for the convenience of clear description in the utility model are only used for exemplary reference and are not limited to the non-limiting interpretation or specific usage, and the protection scope of the utility model should not be limited by the possible Chinese translation or specific letters.

[0041] It should also be noted that, in the present document, relational terms such as "first" and "second", and the like, can be used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Claims

1. A circulating water tank for tail gas treatment, characterized in that: include: Box body (1), cooling water inlet (2), circulating water outlet (3), circulating water pump (4), circulating water inlet (5), air inlet (6) and air outlet (7); A liquid level monitoring device (11) and a temperature monitoring device (12) are provided in the box (1). The liquid level monitoring device (11) includes 5 groups of liquid level sensors. The liquid level monitoring device (11) and the temperature monitoring device (12) control the water inflow and water outflow of the box (1) through a controller.

2. A circulating water tank for tail gas treatment according to claim 1, characterized in that: The liquid level monitoring device (11) is arranged on the inner wall of one side of the box body (1), and comprises, from top to bottom, a high-level alarm sensor (111), a water filling stop position sensor (112), a working liquid level sensor (113), a water discharge stop position sensor (114), and a low-level alarm sensor (115).

3. A circulating water tank for tail gas treatment according to claim 2, characterized in that: The temperature monitoring device (12) is arranged close to the circulating water outlet (3) and is located in an area below the height of the low-level alarm sensor (115).

4. The circulating water tank for tail gas treatment according to claim 1, characterized in that: The cooling water inlet (2) is provided on one side of the box body (1), and a circulating water outlet (3) is provided on the other side of the box body (1), and the circulating water outlet (3) is connected to the circulating water pump (4); The air inlet (6) and the air outlet (7) are respectively arranged on both sides of the top plate of the box body (1).

5. The circulating water tank for tail gas treatment according to claim 4, characterized in that: A plurality of circulating water inlets (5) are provided in the box body (1), one end of the circulating water inlet (5) is connected to the circulating water pump (4) via a circulating pipeline, and the other end of the circulating water inlet (5) is connected to a spray port (51).

6. The circulating water tank for tail gas treatment according to claim 5, characterized in that: The plurality of circulating water inlets (5) are evenly distributed in the box (1), and each of the circulating water inlets (5) is connected to a plurality of the spray ports (51) via a pipeline. The spray ports (51) are each provided with an atomizing nozzle on their outer sleeves.

7. The circulating water tank for tail gas treatment according to claim 6, characterized in that: The circulating water inlet (5) is provided in the air inlet (6), the circulating water inlet (5) is connected to the spray port (51), and the spray port (51) is provided with an atomizing nozzle on its outer cover; A circulating water inlet (5) is provided below the air outlet (7), and the circulating water inlet (5) is connected to the spray port (51).

8. The circulating water tank for tail gas treatment according to claim 1, characterized in that: A plurality of partitions (13) are provided in the box body (1), wherein the partitions (13) are solid baffles, and the lower ends of the partitions (13) are fixedly connected to the bottom of the box body (1); The partition (13) is arranged on a side close to the air inlet (6), and a plurality of the partitions (13) are arranged at intervals, and the height of the partitions (13) decreases in sequence along the direction from the air inlet (6) to the air outlet (7).

9. The circulating water tank for tail gas treatment according to claim 1, characterized in that: A condensation particle baffle is laterally arranged in the box body (1).

10. The circulating water tank for tail gas treatment according to claim 1, characterized in that: A detachable observation window is provided on the front of the box (1), and the observation window is made of a transparent material.

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