Tail gas treatment system and method

Abstract

The invention relates to the field of infrared crystal material preparation, in particular to a tail gas treatment system and method. The tail gas treatment system comprises a reaction device; the buffer device is connected with the tail gas outlet of the reaction device and is used for pretreating the tail gas; the first alkaline washing tower is connected with the tail gas outlet of the buffer device and is used for absorbing at least part of H2S and / or H2Se in the tail gas; the second alkaline washing tower is connected with the tail gas outlet of the first alkaline washing tower and is used for absorbing H2S and / or H2Se in the tail gas; the gas control device comprises a gas control cabinet and a protection device; the gas control cabinet is connected with a gas inlet of the reaction device and used for supplying gas to the reaction device, and the protection device is connected with the second alkaline washing tower. According to the tail gas treatment system and method, the tail gas treatment capacity can be improved.

Description

Technical Field

[0001] The present application relates to the field of infrared crystal material preparation, and in particular to an exhaust gas treatment system and method. Background Art

[0002] ZnS and ZnSe are both infrared optical materials with excellent optical properties. At present, chemical vapor deposition (CVD) is mainly used to prepare ZnS and ZnSe. The above process uses high-purity Zn as the main material and reacts with H carried by Ar under high temperature conditions. 2 S.H. 2 Se reaction to generate ZnS and ZnSe products. 2 S.H. 2 Se is one of the main raw materials for preparing infrared optical materials. 2 S is as toxic as cyanide and is a deadly gas, while H 2 Se is more toxic than H 2 S is higher. During the chemical vapor deposition process, some H 2 S.H. 2 Se, argon and the hydrogen generated by the reaction enter the tail gas treatment system and are discharged into the air after being treated to meet environmental emission standards.

[0003] The tail gas treatment system plays a vital role in the entire CVD production process. Therefore, how to improve the tail gas treatment capacity has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides an exhaust gas treatment system and method, which can improve the exhaust gas treatment capability.

[0005] In the first aspect, the present application provides a tail gas treatment system, which includes: a reaction device; a buffer device: connected to the tail gas outlet of the reaction device, used to pre-treat the tail gas; a first alkali washing tower: connected to the tail gas outlet of the buffer device, used to absorb at least part of the H in the tail gas 2 S and / or H 2 Se; The second alkali washing tower: connected to the tail gas outlet of the first alkali washing tower, used to absorb H in the tail gas 2 S and / or H 2 Se; gas control device: including a gas control cabinet and a protection device; the gas control cabinet is connected to the gas inlet of the reaction device and is used to supply gas to the reaction device, and the protection device is connected to the second alkali washing tower.

[0006] In some embodiments, a spray pipe is disposed at the upper portion of the first alkali washing tower, and a spray port is disposed on the side wall of the spray pipe.

[0007] In some embodiments, a vacuum pump is provided between the reaction device and the buffer device, and the buffer device is used to remove oily substances generated in the process of the tail gas passing through the vacuum pump.

[0008] In some embodiments, at least one first opening is provided above the buffer device for connecting a vacuum pump.

[0009] In some embodiments, the side wall of the buffer device is provided with a second opening for connecting to the first alkali washing tower.

[0010] In some embodiments, a third opening is provided below the second opening for discharging the oil-containing substance in the buffer device.

[0011] In some embodiments, the second alkali washing tower includes a primary alkali washing tower and a secondary alkali washing tower which are arranged in series; optionally, a swirl plate is arranged in the middle of the primary alkali washing tower and the secondary alkali washing tower, and a hollow filler is arranged above the swirl plate.

[0012] In some embodiments, the protection device is connected to the tail gas inlet of the secondary alkali washing tower through a pipeline.

[0013] In some embodiments, the tail gas treatment system further comprises an axial flow fan disposed at the tail gas outlet of the secondary alkali washing tower; the axial flow fan is used to provide exhaust capacity for the first alkali washing tower and the second alkali washing tower.

[0014] In some embodiments, the exhaust gas treatment system further includes an exhaust chimney connected to the axial flow fan, and the exhaust chimney is used to discharge the treated exhaust gas.

[0015] In some embodiments, the tail gas treatment system further includes an alkali solution supply device; the alkali solution supply device is respectively connected to the lower part of the first alkali washing tower and the second alkali washing tower, and is used to supply alkali solution to the first alkali washing tower and the second alkali washing tower.

[0016] In some embodiments, the exhaust treatment system also includes an exhaust control component and an exhaust control system; the exhaust control component is used to control the exhaust treatment system; the exhaust control system is connected to the exhaust control component through electrical connection or signal connection for monitoring and controlling the exhaust control component.

[0017] In a second aspect, the present application provides a tail gas treatment method, which is performed by the tail gas treatment system of the first aspect of the present application.

[0018] In the embodiment of the present application, a first alkali washing tower is arranged between the reaction device and the second alkali washing tower, and the first alkali washing tower is used to absorb at least part of the H in the tail gas. 2 S and / or H 2 Se, increased exhaust gas treatment system to remove H 2 S and / or H 2The absorption amount of Se is increased, thereby improving the exhaust gas treatment capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference numerals are used to represent the same components throughout the accompanying drawings.

[0020] Figure 1 A schematic diagram of the structure of an exhaust gas treatment system provided in some embodiments of the present application;

[0021] Figure 2 A schematic diagram of the structure of a spray pipe in an exhaust gas treatment system provided in some embodiments of the present application;

[0022] Figure 3 A schematic diagram of the structure of a buffer device in an exhaust gas treatment system provided in some embodiments of the present application;

[0023] Figure 4 Another structural schematic diagram of a buffer device in an exhaust gas treatment system provided in some embodiments of the present application;

[0024] Figure 5 A block diagram of an exhaust control component and an exhaust control system provided for some embodiments of the present application.

[0025] Description of reference numerals:

[0026] 10. Reaction device;

[0027] 20. Buffer device; 21. First opening; 22. Second opening; 23. Third opening;

[0028] 30. The first alkali washing tower; 31. The first circulating water pump; 32. The spray pipe; 33. The spray port;

[0029] 40. Second alkali washing tower; 41. Primary alkali washing tower; 42. Secondary alkali washing tower; 43. Cyclone plate; 44. Hollow filler; 45. Second circulating water pump;

[0030] 50. Gas control device; 51. Gas control cabinet; 52. Protection device;

[0031] 60. Vacuum pump; 70. Axial flow fan; 80. Exhaust chimney;

[0032] 90. Alkali solution supply device; 91. Alkali solution supply pump. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings, but it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0035] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0036] In the description of the embodiments of the present application, the term "and / or" is merely a term used to describe the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0037] In the description of the embodiments of the present application, the term "plurality" refers to more than two (including two).

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] In the description of the embodiments of the present application, the terms "first", "second", etc. are only used to distinguish different objects and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary and secondary relationship of the indicated technical features.

[0040] In the related art, during the process of preparing infrared optical materials such as ZnS and ZnSe by chemical vapor deposition (CVD), a two-stage alkali scrubbing tower connected in series is usually used to treat the tail gas. However, the tail gas treatment capacity of the treatment system is insufficient.

[0041] In view of this, the present application provides an exhaust gas treatment system and method, which can improve the exhaust gas treatment capability.

[0042] The present application embodiment provides a tail gas treatment system, such as Figure 1 As shown, the exhaust gas treatment system includes:

[0043] Reaction device 10;

[0044] Buffer device 20: connected to the tail gas outlet of the reaction device 10, used for pre-treating the tail gas;

[0045] The first alkali washing tower 30 is connected to the tail gas outlet of the buffer device 20 and is used to absorb at least part of the H in the tail gas. 2 S and / or H 2 Se;

[0046] The second alkali washing tower 40 is connected to the tail gas outlet of the first alkali washing tower 30 and is used to absorb H in the tail gas. 2 S and / or H 2 Se;

[0047] The gas control device 50 includes a gas control cabinet 51 and a protection device 52 . The gas control cabinet 51 is connected to the gas inlet of the reaction device 10 for supplying gas to the reaction device 10 . The protection device 52 is connected to the second alkali washing tower 40 .

[0048] In the reaction device 10, high-purity zinc and H 2 S or H 2 In the chemical vapor deposition reaction of Se, the protective device refers to a container with sealing performance.

[0049] Gas control cabinet is used to adjust H 2 S and / or H 2 The gas flow of Se has many internal pipe connections and they are connected in series, so the risk of gas leakage is relatively high. The protection device can protect the gas control cabinet. In the event of a leak in the gas control cabinet, the leaked gas can be promptly transported to the second alkali washing tower for treatment, reducing the further spread of the leaked gas.

[0050] In the embodiment of the present application, a first alkali washing tower is arranged between the reaction device and the second alkali washing tower, and the first alkali washing tower is used to absorb at least part of the H in the tail gas. 2 S and / or H 2 Se increases the H 2 S and / or H 2 The absorption amount of Se is increased, thereby improving the exhaust gas treatment capacity.

[0051] The exhaust gas includes H 2 In the case of Se, H 2Se is easily decomposed to form selenium, which is sticky and can cause the spray head of the second alkali washing tower to be blocked. By setting up the first alkali washing tower, at least part of the H in the tail gas can be absorbed. 2 Se, reducing H 2 The selenium element generated by the decomposition of Se blocks the spray head of the second alkali washing tower, thereby improving the tail gas treatment capacity.

[0052] In some embodiments, H 2 S and / or H 2 Se gas can be delivered from a gas cylinder to a gas control cabinet 51 through a gas delivery pipeline (not shown). The gas control cabinet is used to control H 2 S and / or H 2 Se flow.

[0053] In some embodiments, the gas introduced into the reaction device may include H 2 S and / or H 2 Se, and Argon.

[0054] In some embodiments, the reaction device 10 may be a deposition furnace. In the deposition furnace, high-purity zinc and H 2 S or H 2 Se undergoes chemical vapor deposition reaction to generate ZnS or ZnSe, and H 2 The tail gas in the present embodiment includes unreacted H 2 S or H 2 Se, and H 2 and argon.

[0055] In some embodiments, the protection device 52 is in a negative pressure state. Therefore, in the event of a leak in the gas control cabinet, the leaked gas can be promptly pumped into the second alkali washing tower for treatment, reducing further diffusion of the leaked gas, thereby improving production safety.

[0056] In some embodiments, the protection device 52 may be a protection cover. For example, the protection cover may completely wrap the gas control cabinet and place the inside of the protection cover in a negative pressure environment.

[0057] In some embodiments, a circulating water pump is disposed at the lower part of the first alkali washing tower 30 and the second alkali washing tower 40. For example, a first circulating water pump 31 is disposed at the lower part of the first alkali washing tower 30, and a second circulating water pump 45 is disposed at the lower part of the second alkali washing tower 40.

[0058] It should be noted that the tail gas inlet of the first alkali washing tower is located at the lower part of the first alkali washing tower, and an alkali liquid pool is provided at the lower end of the first alkali washing tower. Similarly, the tail gas inlet of the second alkali washing tower is located at the lower part of the second alkali washing tower, and an alkali liquid pool is provided at the lower end of the second alkali washing tower. The alkali liquid in the alkali liquid pool is transported to the spray head at the top of the tower by a circulating water pump, and the alkali liquid flowing out of the spray head flows from top to bottom, and contacts with the tail gas from bottom to top in countercurrent, thereby realizing the acid-base neutralization treatment of the tail gas.

[0059] In some embodiments, the first alkali washing tower and the second alkali washing tower may also be provided with a pH meter for monitoring the pH of the alkali solution in the first alkali washing tower or the second alkali washing tower.

[0060] In some embodiments, the first alkali washing tower and the second alkali washing tower may also be provided with an alkali solution heating device for heating the alkali solution, thereby improving the absorption efficiency of the alkali solution on the tail gas.

[0061] See also Figure 1 and Figure 2 In some embodiments, a spray pipe 32 is provided at the upper part of the first alkali washing tower 30, and a spray port 33 is provided on the side wall of the spray pipe 32. By providing the spray pipe, the outlet area of ​​the spray port can be increased, and H can be further reduced. 2 The problem of spray port blockage during Se treatment is solved, thereby further improving the tail gas treatment capacity. For example, the nominal diameter of the spray pipe can be DN30.

[0062] In some embodiments, the spray pipe 32 is placed horizontally on the upper part of the first alkali washing tower 30, and the opening direction of the spray port 33 faces upward. In this way, the alkali solution can flow down from the spray pipe in an arc shape, increasing the contact area between the alkali solution and the tail gas, thereby improving the absorption capacity of the first alkali washing tower for the tail gas.

[0063] In some embodiments, the shape of the spray port 33 may be one or more of square, rectangular, circular, and triangular.

[0064] In some embodiments, two adjacent spray ports are arranged at the same distance above the spray pipe, so that the alkali solution flowing out of the spray ports can be more evenly distributed, thereby increasing the contact area between the alkali solution and the tail gas, and improving the absorption capacity of the first alkali washing tower for the tail gas.

[0065] In some embodiments, the material of the first alkali washing tower may be stainless steel, thereby increasing the corrosion resistance of the first alkali washing tower.

[0066] In some embodiments, a vacuum pump 60 may be provided between the reaction device 10 and the buffer device 20, and the buffer device 20 is used to remove oily substances generated in the process of the tail gas passing through the vacuum pump.

[0067] In the embodiment of the present application, the tail gas in the reaction device can be transported to the buffer device through the vacuum pump. However, since the temperature of the tail gas is usually high, the oily substances in the vacuum pump will inevitably enter the subsequent treatment process with the tail gas. The oily substances will undergo saponification reaction with the alkaline substances, causing the contamination of the alkali solution inside the first alkali washing tower and the second alkali washing tower, increasing the cost of wastewater treatment.

[0068] By providing a buffer device, the saponification reaction between oil substances and alkaline substances can be reduced, the pollution of the alkaline solution inside the first alkali washing tower and the second alkali washing tower can be reduced, and the cost of wastewater treatment can be reduced.

[0069] In some embodiments, the first alkali washing tower and the second alkali washing tower are also provided with drainage pipelines (not shown) for discharging waste water in the first alkali washing tower and the second alkali washing tower.

[0070] Figure 3 A schematic diagram of the structure of a buffer device in an exhaust gas treatment system provided in some embodiments of the present application; Figure 4 Another schematic diagram of the structure of the buffer device in the exhaust gas treatment system provided in some embodiments of the present application.

[0071] See also Figure 1 , Figure 3 and Figure 4 In some embodiments, at least one first opening 21 is provided above the buffer device 20 for connecting the vacuum pump 60 .

[0072] For example, the number of the first openings may be 1, 2, 3, 4, 5 or 6, and the number of the first openings may be determined according to the processing capacity of the system. A pipeline with a nominal diameter of DN75 may be connected to the first opening, and the diameter of the pipeline connected to the first opening may be determined according to the flow rate of the exhaust gas.

[0073] In some embodiments, a second opening 22 is provided on the side wall of the buffer device 20 for connecting to the first alkali washing tower 30 .

[0074] The second opening can be connected to a pipeline with a nominal diameter of DN 300. The principle for selecting the diameter of the pipeline connected to the second opening is the same as that of the first opening, and will not be repeated here.

[0075] In some embodiments, a third opening 23 is provided below the second opening 22 for discharging the oily substance in the buffer device 20. For example, the third opening 23 may be located on the same side of the buffer device 20 as the second opening 22, or the third opening 23 may be located on a different side of the buffer device 20 than the second opening 22. For example, the third opening may be connected to a pipeline with a nominal diameter of DN15.

[0076] It should be noted that the third opening is usually in a closed state. By regularly opening the third opening, the oily substances inside the buffer device can be discharged, thereby reducing the accumulation of oily substances in the buffer device and causing contamination of the alkali solution inside the first alkali washing tower and the second alkali washing tower.

[0077] In some embodiments, the buffer device 20 may be a sealed box structure, for example, a buffer box, and the material of the buffer box may include but is not limited to polypropylene (PP).

[0078] It should be noted that liquid is usually not placed in the buffer device, and the gaseous oil-containing substance with a relatively high temperature becomes liquid after being air-cooled in the buffer device.

[0079] In some embodiments, the second alkali washing tower 40 may include a primary alkali washing tower 41 and a secondary alkali washing tower 42 connected in series. By connecting the primary alkali washing tower and the secondary alkali washing tower in series, harmful gases in the tail gas can be completely absorbed, thereby further improving the treatment effect of the tail gas.

[0080] In some embodiments, a cyclone plate 43 is disposed in the middle of the primary alkali washing tower 41 and the secondary alkali washing tower 42, and a hollow filler 44 is disposed above the cyclone plate 43. By disposing the hollow filler above the cyclone plate, the path of the tail gas circulation can be increased, the contact time between the tail gas and the alkali solution can be increased, and the alkali solution and the H in the tail gas can be separated. 2 S and / or H 2 Se reacts fully, thereby improving the efficiency of exhaust gas treatment and making the final exhaust gas meet environmental protection requirements.

[0081] In some embodiments, the hollow filler 44 may be a hollow ball, thereby reducing the transmission resistance of the exhaust gas and further improving the exhaust gas treatment capability.

[0082] In some embodiments, the protection device 52 is connected to the tail gas inlet of the secondary alkali washing tower through a pipeline.

[0083] In this way, when a gas control cabinet leaks, the gas in the protection device can be absorbed by the secondary alkali washing tower in time, and the gas outlet of the protection device can be closer to the axial flow fan, that is, the pipeline between the protection device and the second alkali washing tower can be closer to the axial flow fan, thereby enhancing the negative pressure in the pipeline and reducing the exhaust gas in the secondary alkali washing tower from entering the protection device through the pipeline.

[0084] Please continue reading Figure 1 In some embodiments, the tail gas treatment system further includes an axial flow fan 70 disposed at the tail gas outlet of the secondary alkali washing tower 42 .

[0085] The axial flow fan 70 is used to provide air extraction capability for the first alkali washing tower 30 and the second alkali washing tower 40. Similarly, the axial flow fan 70 can also extract air from the inside of the protective device 52 to form a negative pressure inside the protective device 52.

[0086] In some embodiments, the number of axial flow fans may be one or more. For example, the number of axial flow fans is 2. The two axial flow fans may be connected in parallel, with one axial flow fan being a spare.

[0087] In some embodiments, the exhaust gas treatment system further includes an exhaust chimney 80 connected to the axial flow fan, and the exhaust chimney 80 is used to discharge the treated exhaust gas.

[0088] In some embodiments, the tail gas treatment system further includes an alkali solution supply device 90. Exemplarily, the alkali solution supply device 90 may be an alkali supplement tank.

[0089] In some embodiments, the alkali solution supply device 90 is connected to the lower part of the first alkali washing tower 30 and the second alkali washing tower 40, respectively, for supplying alkali solution to the first alkali washing tower and the second alkali washing tower. Exemplarily, the alkali solution supply device 90 is connected to the alkali solution inlet of the lower part of the first alkali washing tower 30 and the second alkali washing tower 40, respectively.

[0090] In some embodiments, the alkali solution supply device 90 is connected to the lower part of the primary alkali washing tower 41 and the secondary alkali washing tower 42 respectively.

[0091] In some embodiments, the alkali solution in the alkali solution supply device may include a saturated NaOH solution and / or a saturated NaClO solution.

[0092] Exemplarily, the alkali solution in the alkali solution supply device is a saturated NaOH solution and a saturated NaClO solution.

[0093] In some embodiments, the mass ratio of the saturated alkaline NaOH solution to the saturated NaClO solution is (2-7):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, or a range consisting of any two of the above values.

[0094] By setting the mass ratio of the saturated NaOH solution to the NaClO solution within the above range, the saponification reaction between the oil-containing substance and the alkali solution can be further reduced, thereby improving the treatment efficiency.

[0095] In some embodiments, the alkali solution in the first alkali washing tower is a saturated NaOH solution and a saturated NaClO solution, and the alkali solution in the second alkali washing tower is a saturated NaOH solution. Alternatively, the alkali solution in the first alkali washing tower is a saturated NaClO solution, and the alkali solution in the second alkali washing tower is a saturated NaOH solution and a saturated NaClO solution. Similarly, the alkali solutions in the primary alkali washing tower and the secondary alkali washing tower can be the same or different.

[0096] During the circulation process of the first alkali washing tower and the second alkali washing tower, the concentration of the alkali solution gradually decreases, so it is necessary to regularly add alkali solution to the first alkali washing tower and the second alkali washing tower.

[0097] In some embodiments, the alkali solution supply device 90 delivers alkali solution to the first alkali washing tower 30 and the second alkali washing tower 40 through an alkali solution supply pump 91 .

[0098] like Figure 5 As shown, in some embodiments, the exhaust treatment system further includes an exhaust control component and an exhaust control system.

[0099] In some embodiments, an exhaust control assembly is used to control an exhaust treatment system.

[0100] In some embodiments, the exhaust gas control component is used to control the start and stop of the axial flow fan, the circulating water pump, the alkali washing tower pH meter, the alkali solution supply device, and the alkali solution heating device, as well as to monitor the axial flow fan, the circulating water pump, the alkali washing tower pH meter, the alkali solution supply device, and the alkali solution heating device.

[0101] In some embodiments, the exhaust control system is electrically connected or signal connected to the exhaust control component for monitoring and controlling the exhaust control component.

[0102] In the embodiment of the present application, the exhaust control system monitors and controls the exhaust control components, so that remote control and real-time control of the axial flow fan, circulating water pump, alkali washing tower pH meter, alkali solution supply device, and alkali solution heating device can be achieved, thereby improving the automation level of the exhaust gas treatment system.

[0103] In some embodiments, the exhaust gas control system may be a PLC control system, for example, a Siemens PLC system.

[0104] In some embodiments, the PLC control system can realize centralized continuous control through a host computer. For example, the host computer can be a computer.

[0105] In the embodiment of the present application, a high-speed central processing unit is selected with a computing speed of 0.01 μm; a high-speed gigabit network is used for the transmission network, and a parallel open-loop network is used for the slave network to prevent other stations from being unable to work normally due to power failure at a certain intermediate station; industrial control operations are processed in a hierarchical manner.

[0106] In some embodiments, the PLC control system may include a primary system and a secondary system.

[0107] In some embodiments, the primary system may include an administrator level (ES); the secondary system may include an operator level (OS).

[0108] The operator level can only perform general and simple parameter settings on the equipment, while the administrator level can write, modify, and adjust the production process data at any time.

[0109] In some embodiments, the PLC control system may be provided with an operation interface and an operation station corresponding to an operator level, and may be provided with an operation interface and an operation station corresponding to an administrator level.

[0110] This allows simultaneous monitoring of equipment operation, and the original program can be modified and maintained at any time under administrator-level authority. Each operator and administrator level can monitor and record operating parameters at the same time, with one-to-one data reading and writing, thus solving the problem of subsequent stations stopping working when a station fails or crashes during the process.

[0111] In addition, the PLC control system of the embodiment of the present application adopts one-to-one reading for the special network (RS485) communication network, which improves the reading speed, compensates for the polling time and data loss in the inherent communication, and enhances the stability of the data and the ability to adjust in an emergency.

[0112] The embodiment of the present application realizes real-time online detection by setting up a PLC control system, automatically replenishing alkali solution, remotely operating the circulation system, and measuring the online pH value in real time, thereby realizing remote manual operation. The system can also be alarmed for minor or serious faults, realizing the entire process of automatic production control, and all equipment can be monitored in real time in the monitoring room, reducing the labor intensity of operators and improving production efficiency and safety production capabilities.

[0113] The present application provides a tail gas treatment method, which is performed by the tail gas treatment system of the first aspect of the present application.

[0114] The following describes the treatment process of the exhaust gas generated by the chemical vapor deposition method in conjunction with the exhaust gas treatment system and method of the embodiments of the present application.

[0115] H 2 S or H 2 Se gas is transported from the gas cylinder to the gas control cabinet through the gas delivery pipeline, and its flow is controlled by the gas control cabinet, and then transported to the deposition furnace together with argon gas. 2 S or H 2 Se undergoes CVD reaction, and the unreacted H 2 S or H 2 Se and hydrogen generated during the deposition process are transported to the buffer tank by a vacuum pump under the carrier of argon gas. Then, after being treated in the first alkali cleaning tower, the stainless steel alkali cleaning tower is transported to the first alkali cleaning tower and the second alkali cleaning tower. 2 S.H. 2Se reacts with saturated NaOH and saturated sodium hypochlorite to generate sodium sulfide or sodium selenide and water. The remaining hydrogen and argon are discharged into the air through the exhaust chimney under the negative pressure generated by the operation of the axial flow fan.

[0116] At the same time, the gas control cabinet is completely covered with a protective device to keep the gas control cabinet protective device in a negative pressure state. Similarly, the pipeline between the protective device and the secondary alkali washing tower is in a negative pressure state under the action of the axial flow fan. In the event of gas leakage at the gas control cabinet, H 2 S or H 2 Se gas is pumped into the secondary alkali washing tower for treatment to reduce further diffusion of the leaked gas.

[0117] The tail gas control component controls the start and stop and monitoring functions of the axial flow fan, circulating water pump, alkali washing tower pH meter, alkali solution supply device, and alkali solution heating device. The PLC control system is used to control and monitor the tail gas control component.

[0118] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A tail gas treatment system, characterized in that: The tail gas treatment system comprises: Reaction device; Buffer device: connected to the tail gas outlet of the reaction device, used for pre-treating the tail gas; A first alkali washing tower: connected to the tail gas outlet of the buffer device, used to absorb at least part of the H2S and / or H2Se in the tail gas; The second alkali washing tower is connected to the tail gas outlet of the first alkali washing tower and is used to absorb H2S and / or H2Se in the tail gas; Gas control device: comprising a gas control cabinet and a protection device; the gas control cabinet is connected to the gas inlet of the reaction device and is used to supply gas to the reaction device, and the protection device is connected to the second alkali washing tower.

2. The exhaust gas treatment system according to claim 1, characterized in that: A spray pipe is arranged at the upper part of the first alkali washing tower, and a spray port is arranged on the side wall of the spray pipe.

3. The exhaust gas treatment system according to claim 1, characterized in that: A vacuum pump is provided between the reaction device and the buffer device, and the buffer device is used to remove oily substances generated in the process of the tail gas passing through the vacuum pump; and / or, At least one first opening is provided above the buffer device for connecting the vacuum pump; and / or, The side wall of the buffer device is provided with a second opening for connecting the first alkali washing tower; and / or, A third opening is provided below the second opening for discharging the oil-containing substance in the buffer device.

4. The exhaust gas treatment system according to claim 1, characterized in that: The second alkali washing tower comprises a primary alkali washing tower and a secondary alkali washing tower which are arranged in series with each other; Optionally, a swirl plate is provided in the middle of the primary alkali washing tower and the secondary alkali washing tower, and a hollow filler is provided above the swirl plate.

5. The exhaust gas treatment system according to claim 4, characterized in that: The protection device is connected to the tail gas inlet of the secondary alkali washing tower through a pipeline.

6. The exhaust gas treatment system according to claim 4, characterized in that: The tail gas treatment system also includes an axial flow fan arranged at the tail gas outlet of the secondary alkali washing tower; The axial flow fan is used to provide suction capacity for the first alkali washing tower and the second alkali washing tower.

7. The exhaust gas treatment system according to claim 6, characterized in that: The exhaust gas treatment system also includes an exhaust chimney connected to the axial flow fan, and the exhaust chimney is used to discharge the treated exhaust gas.

8. The exhaust gas treatment system according to claim 1, characterized in that: The tail gas treatment system also includes an alkali solution supply device; The alkali solution supply device is connected to the lower part of the first alkali washing tower and the second alkali washing tower respectively, and is used to supply alkali solution to the first alkali washing tower and the second alkali washing tower.

9. The exhaust gas treatment system according to claim 1, characterized in that: The exhaust gas treatment system also includes an exhaust gas control component and an exhaust gas control system; The exhaust gas control component is used to control the exhaust gas treatment system; The exhaust control system is electrically connected or signal connected to the exhaust control component for monitoring and controlling the exhaust control component.

10. A tail gas treatment method, characterized in that: The tail gas treatment method is carried out by the tail gas treatment system according to any one of claims 1 to 9.

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