Hydrogen-containing tail gas treatment device and method
By using excessive air in the sealed shell and mixing and heating it, the combustion instability, high cost and explosion risk of hydrogen treatment in the semiconductor process exhaust gas is solved, and efficient and safe hydrogen oxidation treatment is achieved, reducing operating costs and maintenance Difficulty.
Patent Information
- Application Number
- CN202411508711.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2024-12-27
AI Technical Summary
The prior art has problems of instability in combustion, high cost, explosion risk and low efficiency when dealing with hydrogen in semiconductor process exhaust gas. Traditional catalytic treatment methods are difficult to effectively deal with in open hydrogen-containing exhaust gases, and the indirect reaction methods are high maintenance costs. .
A hydrogen-containing exhaust gas treatment device is designed, which uses excessive air to dynamically mix with the exhaust gas in the sealed shell, and an oxidation reaction is carried out at 850±10°C through a heating device to avoid catalysts and indirect reaction substances and achieve stable oxidation of hydrogen.
This method realizes safe and efficient treatment of hydrogen, reduces operating costs, avoids the risk of burning and explosion, simplifies the equipment structure, improves processing efficiency and maintainability.
Smart Images
Figure CN119186225A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a device for treating hydrogen contained in hydrogen-containing tail gas, and also relates to a method for treating hydrogen contained in hydrogen-containing tail gas. Background Art
[0002] Since the components in tail gas are often relatively complex, the treatment of each component in tail gas cannot be completed in one tail gas treatment equipment. Semiconductor process tail gas basically contains hydrogen. If it is not handled properly, the hydrogen contained in it is more likely to cause an explosion. Since hydrogen is flammable, has poor water solubility, and is difficult to dissolve in other solutes, its treatment is often specialized. Therefore, for semiconductor process tail gas, it is usually necessary to use dedicated process equipment at a given stage to treat the hydrogen contained in it.
[0003] A common method for treating hydrogen in hydrogen-containing tail gas is combustion. The combustion method seems simple and direct, but it is not the case in actual working conditions. First of all, in applications where hydrogen can be used directly as fuel, there are relatively high requirements for the concentration of hydrogen, and the hydrogen content in semiconductor process tail gas often cannot meet this requirement. Therefore, before the hydrogen-containing tail gas is burned, other components in the semiconductor process tail gas need to be treated first, and the hydrogen-containing tail gas needs to be concentrated at the same time to make the hydrogen content reach the condition that can be directly burned. A burner is also provided to ignite hydrogen at a relatively high temperature. Since hydrogen combustion is unstable under this working condition, the equipment used to ignite hydrogen in the burner needs to work continuously, and the actual processing cost is very high.
[0004] Another common method for treating hydrogen-containing tail gas is catalytic treatment, which is mainly used for treating hydrogen in low-concentration hydrogen-containing waste gas. In this catalytic treatment method, precious metals platinum or palladium (slightly cheaper than metal platinum) are used as catalysts to ensure that low-concentration hydrogen still has a relatively stable oxidation reaction. The current application of catalytic treatment methods is mainly reflected in catalytic oxidation methods, which are mostly used in fuel cells that meet the controllable cost of precious metals. In other words, if its application scenario is transferred to the treatment of hydrogen-containing tail gas, the actual treatment cost will be relatively high. In addition, catalytic treatment methods are more likely to cause explosion risks in relatively open hydrogen-containing tail gas treatment. Therefore, people often need to perform extremely strict temperature control on the catalytic treatment process to avoid the closed container used for catalytic treatment reaching the explosion limit.
[0005] In some implementations, the hydrogen in the hydrogen-containing tail gas is treated by an indirect reaction, which requires special equipment for assistance. The special equipment is configured as a tank structure, in which a reaction tank is provided, wherein a fixed cylinder is provided in the center of the reaction tank, and a copper column is provided in the fixed cylinder, and air holes are evenly distributed on the fixed cylinder, and the hydrogen-containing tail gas is introduced into the fixed cylinder through the air holes. Among them, the copper column is equipped with a corresponding heating device to maintain the copper column at a predetermined temperature. At the same time, the fixed cylinder introduces air through a pipeline to oxidize the surface of the copper column. The copper column surface will generate copper oxide or cuprous oxide due to oxidation, and the copper oxide or cuprous oxide will react with hydrogen to generate copper and water. Through this indirect reaction, the hydrogen contained in the hydrogen-containing tail gas can be removed at a relatively low temperature. This treatment method needs to avoid direct reaction between hydrogen and oxygen, and the reaction temperature is generally lower than 550°C. Under this condition, the oxidation reaction of copper is relatively slow, and the reaction conforms to the parabolic law, that is, the initial reaction rate of the oxidation reaction is the fastest, and then it will gradually decrease. In other words, this type of treatment method is very inefficient. At the same time, for example, the copper generated by the reaction of copper oxide and hydrogen will not directly adhere to the copper column, but will settle. If not handled properly, the generated copper will be deposited at the bottom of the fixed cylinder, and the subsequent maintenance cost is very high. In addition, the copper column will be continuously worn out and needs to be replaced regularly, which further increases the difficulty of subsequent maintenance. Summary of the invention
[0006] The purpose of the present invention is to provide a hydrogen-containing tail gas treatment device with a simple structure and relatively good operation reliability. The present invention also provides a hydrogen-containing tail gas treatment method.
[0007] According to a first aspect of an embodiment of the present invention, there is provided a hydrogen-containing tail gas treatment device, comprising: The shell has a reaction chamber, and the reaction chamber is provided with an air inlet at the lower end and an air outlet at the upper part; An exhaust gas inlet pipe is inserted into the reaction chamber from the air inlet and is used to introduce hydrogen-containing exhaust gas; The air intake pipe has a first configuration or a second configuration, wherein in the first configuration, the air intake pipe is nested outside the exhaust gas intake pipe and inserted into the reaction chamber to introduce compressed air into the reaction chamber; in the second configuration, the shell is provided with an air dispersion chamber at the lower side of the reaction chamber, a baffle is provided between the air dispersion chamber and the reaction chamber, the air inlet is correspondingly provided on the baffle, the air intake pipe is installed on the shell where the air dispersion chamber is located, and a flow gap or a sealed connection is left between the exhaust gas intake pipe and the air inlet. If it is a sealed connection, air holes are arranged around the air inlet; A heating device, the heating device is mounted on the housing, and the heating body included in the heating device is located in the reaction chamber to heat a predetermined reaction area, the reaction area being an exhaust area common to the exhaust gas intake pipe and the air intake pipe; a temperature measuring device for measuring the temperature of the reaction zone; and The control unit is connected to the temperature measuring device and outputs a control signal to control the heating device so as to control the temperature in a closed loop.
[0008] Optionally, if the air intake pipe is nested outside the exhaust gas intake pipe, the length of the air intake pipe inserted into the reaction chamber is shorter than the length of the exhaust gas intake pipe inserted into the reaction chamber.
[0009] Optionally, a water retaining eave is obliquely provided above the heating device to prevent condensed water dripping from above from contacting the heating device.
[0010] Optionally, the heating device is a heating rod, the seat of which is mounted on the first side of the housing defining the reaction chamber; Correspondingly, the water retaining eaves are connected from the first side to the second side and are inclined downward; The first side is opposite to the second side.
[0011] Optionally, the end of the water retaining eave has an arc-shaped portion with the center at the bottom; The end of the arc portion has a blade-shaped head.
[0012] Optionally, in the second configuration, a water outlet is provided at the bottom of the air dispersion chamber; The water outlet is connected with a drainage pipe; The drain pipe has a U-shaped water bend for water sealing.
[0013] Optionally, the gas outlet is equipped with an exhaust pipe, and the exhaust pipe is provided with a pressure differential gauge; Correspondingly, the exhaust pipe is connected with a suction device.
[0014] According to a second aspect of an embodiment of the present invention, a method for treating hydrogen-containing tail gas is provided, the method comprising: Introducing compressed air and hydrogen-containing tail gas into a closed shell, the introduced compressed air and hydrogen-containing tail gas are dynamically mixed in a predetermined reaction zone in the shell, wherein the compressed air is an excess oxidant relative to the hydrogen-containing tail gas; The reaction zone was heated by a heating device, and the temperature of the reaction zone was maintained at 850±10°C by closed-loop control.
[0015] Optionally, the flow ratio of compressed air to hydrogen-containing exhaust gas is not less than 7:1 and not higher than 13:1, and is positively correlated with the hydrogen concentration in the hydrogen-containing exhaust gas.
[0016] Optionally, the gas after the reaction in the reaction zone is extracted by forced extraction.
[0017] In an embodiment of the present invention, the provided hydrogen-containing tail gas treatment device adopts a simple structure to achieve complex treatment. First, a shell is used to construct a reaction chamber, which has an air inlet and an air outlet, wherein the air inlet is used to introduce the tail gas inlet pipe and the air inlet pipe, and then a heating device is arranged in the exhaust area common to the tail gas inlet pipe and the air inlet pipe, so that the hydrogen in the tail gas and the oxygen in the air can produce an oxidation reaction by heating at 850±10°C before the compressed air and the tail gas are excessively mixed. Insufficient mixing can make the reaction more controllable and less likely to cause explosion problems. In addition, no catalyst is required in the reaction process, and no indirect reaction substances are required. The overall structure is compact and the overall operating cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 Schematic diagram of the structure of a hydrogen-containing tail gas treatment device in one embodiment.
[0019] Figure 2 for Figure 1 A magnified view of part I.
[0020] In the figure: 1. exhaust gas intake pipe, 2. air intake pipe, 3. air dispersion chamber, 4. baffle, 5. reaction chamber, 6. upward channel, 7. water retaining eaves, 8. exhaust chamber, 9. exhaust pipe, 10. differential pressure gauge, 11. insulation shell, 12. heating rod, 13. thermocouple, 14. nozzle, 15. water bay, 16. drain pipe, 17. blade head, 18. convex transition part, 19. water flowing surface. DETAILED DESCRIPTION
[0021] In the embodiment of the present invention, excess air is used to oxidize hydrogen in the hydrogen-containing tail gas at a predetermined temperature. The excess air may seem to be a waste, but compared with the traditional hydrogen-containing tail gas treatment method, the overall treatment cost is not high. At the same time, it should be known that the use of excess air does not lead to an increase in pollutants, nor does it increase the burden of subsequent tail gas treatment.
[0022] Furthermore, in the embodiment of the present invention, the excess air also serves as a cooling medium to prevent the rest of the chamber except the reaction zone of the reaction chamber from being overheated.
[0023] In view of the fact that the concentration of hydrogen in the tail gas has a time-varying characteristic, while the oxygen content in the air is relatively stable, in other words, the chemical heat generated by the reaction is not stable, so a heating device such as a heating rod 12 is used, the purpose of which is to adjust the temperature of a predetermined reaction zone in the reaction chamber according to actual working conditions, but except for the reaction zone, the temperature of the remaining areas is not high. Therefore, the embodiment of the present invention also involves the problem of handling condensed water.
[0024] The following focuses on describing the hydrogen-containing tail gas treatment device. While describing the hydrogen-containing tail gas treatment device, a comprehensive explanation of the hydrogen-containing tail gas treatment method is given. The two complement each other, so that the treatment of hydrogen-containing tail gas can be completed under the condition that the process equipment used is relatively simple.
[0025] Based on the foregoing, it can be known that in the embodiments of the present invention, the reaction of hydrogen in the hydrogen-containing exhaust gas with oxygen in excess air under predetermined temperature conditions is carried out without the aid of a catalyst or an intermediate substance, but with the aid of a pure oxidation reaction, the by-product is water, and there are no consumables. Therefore, its later maintainability is relatively good.
[0026] The controlled reaction is completed in a closed container. Figure 1 The illustrated structure has a heat-insulating shell 11, which can be in the shape of a tank as a whole, and is sealed at both ends. For the convenience of description, the parts used for sealing the upper and lower ends are respectively referred to as the upper cover and the lower cover, wherein the upper cover is provided with an air outlet, which can be referred to as an exhaust port in the following embodiments because it is configured in a forced exhaust manner. The corresponding pipeline installed at the air outlet is Figure 1 The exhaust pipe 9 shown in FIG.
[0027] Figure 1 In the embodiment, the heat-insulating shell 11 has a plurality of chambers, wherein the chamber in the middle is the reaction chamber 5 , and the oxidation reaction of hydrogen in the hydrogen-containing tail gas is mainly completed in the reaction chamber 5 .
[0028] Below the reaction chamber 5 is the air dispersion chamber 3. The air inlet pipe 2 is connected to the air dispersion chamber 3 from the side, which is beneficial to the dispersion of the compressed air after entering the air dispersion chamber 3 and avoids the unevenness of the beam gas supply.
[0029] The exhaust gas intake pipe 1 passes through the air dispersion chamber 3 upward from the lower end of the heat-insulating shell 11 and enters the reaction chamber 5. Accordingly, the exhaust gas intake pipe 1 is airtightly connected to the lower cover. It should be known that this airtight connection is a static connection, and the exhaust gas intake pipe 1 does not involve mechanical wear and tear, and can be fixed to the lower cover by, for example, welding.
[0030] In addition, it should be known that if the convection resistance is less considered, for example, the exhaust gas intake pipe 1 can be connected from the side of the insulation shell 11, and then the elbow is used to transform it into Figure 1 The up-and-down flowing pipeline parts shown in the figure are conventional transformations in the art.
[0031] The exhaust gas intake pipe 1 can also be installed on the lower cover in a detachable connection. Since it is a static connection and as mentioned above, only the reaction zone in the reaction chamber 5 has a relatively high temperature, and the air dispersion chamber 3 shielded by the baffle 4 can be understood as a cooling chamber, which blocks the thermal influence of heating devices such as the heating rod 12 on the lower structure, that is, the cooperation between the exhaust gas intake pipe 1 and the lower cover can completely use conventional mechanical seals.
[0032] The configuration of the tail gas inlet pipe 1 and the air inlet pipe 2 is configured based on the flow rate, and the flow rate ratio is not less than 7. It should be known that the oxygen content in the air is about 21% (volume fraction), and the hydrogen content in the semiconductor tail gas is affected by many factors such as process conditions, equipment status and operating parameters. The hydrogen content in the tail gas is unstable, but for the same process equipment, a range can be roughly determined, and then the maximum value of the range can be matched to determine the air feed amount, ensuring that excess air is used to relatively well remove the hydrogen in the tail gas and enable the equipment to operate safely.
[0033] Figure 1 A configuration of the reaction chamber 5 is shown in FIG. Figure 1 In the illustrated structure, the baffle 4 is provided in the inner cavity of the heat-insulating shell 11, and the inner cavity of the heat-insulating shell 11 is divided into two basic chambers. The part below the baffle 4 is called the air dispersion chamber 3, and the part above the baffle 4 is called the reaction chamber 5. Figure 1 The illustrated structure also includes an exhaust chamber 8 , but the exhaust chamber 8 can also be used as an exhaust port assembly of the reaction chamber 5 .
[0034] Among them, baffle 4 is Figure 1 A central hole is provided in the middle, but it should be known that the intervention hole opened by the baffle 4 for the exhaust gas intake pipe 1 to intervene from the outside to the reaction chamber 5 does not necessarily need to be a central hole. The position of the intervention hole is determined by the preset position of the reaction zone. Figure 1 The direction in which the outlet of the tail gas intake pipe 1 rushes is the area where the reaction zone is located.
[0035] exist Figure 1 In the illustrated structure, as mentioned above, compressed air is also transported from bottom to top. Accordingly, the diameter of the intervention hole is larger than the outer diameter of the exhaust gas intake pipe 1. Therefore, when the exhaust gas intake pipe 1 passes through the intervention hole, a gap will be left between the exhaust gas intake pipe 1 and the intervention hole, and the gap constitutes a channel for the compressed air to ascend.
[0036] Based on the above description, it can be seen that the air is delivered in the form of compressed air. Figure 1 In the illustrated structure, the gap is represented by the nozzle 14 shown in the figure, that is, the compressed air goes up in a jet manner and quickly dilutes the hydrogen-containing exhaust gas introduced through the exhaust gas intake pipe 1. At the same time, due to its fast flow rate, it is not easy to cause excessive mixing.
[0037] For the convenience of description, the intervention methods of the air intake pipe 2 are divided into two types, among which the intervention method with the aid of the air dispersion chamber 3 is called the second configuration, which can more advantageously avoid excessive mixing of compressed air and hydrogen-containing exhaust gas. In other embodiments, the intervention method of the air intake pipe 2 is called the first configuration, and the air intake pipe 2 is directly introduced in the first configuration by means of nested tubes. Among them, the air intake pipe 2 constitutes an outer tube, and the exhaust gas intake pipe 1 constitutes an inner tube, and the channel between the inner and outer tubes is used to conduct compressed air. In this case, the access method of the nested tubes can refer to the aforementioned access (non-intervention) method of the exhaust gas intake pipe, which will not be repeated here.
[0038] In some embodiments, the intervention hole and the exhaust gas intake pipe 1 can be tightly fitted (interference fit or transition fit) or connected (such as welding), and a group of air holes can be arranged around the intervention hole to facilitate the upward injection of compressed air.
[0039] In addition, the connection between the air intake pipe 2 and the heat-insulating shell 11 is also a static connection, and the seal between the two is also a static seal, which is relatively simple to implement and will not be described in detail here.
[0040] In the embodiment of the present invention, the heating device is not used to ignite hydrogen, but to form a temperature field that enables hydrogen to be oxidized in the air in a non-combustion manner.
[0041] Temperature field, also known as temperature field, refers to the collection of temperatures at various points in a material system. In simple terms, it means that the temperatures in different areas are different, and the temperature distribution is expressed in an explicit way to express different temperatures. You can refer to the well-known expression methods such as contour lines.
[0042] It can be seen from this that for the heating device, the heating of the mixed gas will also present a relatively obvious temperature field.
[0043] In addition, if Figure 1 In the illustrated structure, the shielding of the water retaining eaves 7 makes the airflow after the reaction have a more stable flow direction, and the area that meets the conditions of the reaction zone is also more certain.
[0044] Regarding the reaction zone, as mentioned above, it is determined using temperature parameters, that is, the area where the mixed gas temperature is 850±10°C as mentioned above, and the oxygen and hydrogen in the mixed gas produce an oxidation reaction in this area.
[0045] If the temperature is relatively high, the oxidation reaction can still be maintained, but in the embodiments of the present invention, emphasis is placed on the stable progress of the reaction. In other words, the reaction being too fast or too slow is not the purpose of the present invention, but rather it is desired to maintain the reaction in a relatively stable range, so as to adapt to the flow rate of the compressed air flowing through the air intake pipe 2, and further adapt to the flow rate of the exhaust gas intake pipe 1, so as to make the overall operation more economical.
[0046] The heating device is installed on, for example, a heat-insulating housing 11, and the heating body included in the heating device is located in the reaction chamber to heat a predetermined reaction area. As mentioned above, the reaction area is the exhaust area common to the exhaust gas intake pipe 1 and the air intake pipe 2. The exhaust area can be determined based on, for example, the position of the heating body on the heating rod 12 and the expected heating range.
[0047] exist Figure 1 In the illustrated structure, a thermocouple 13 is used as a temperature measuring device. In the figure, the position of the thermocouple 13 is slightly lower, and the temperature measured is not necessarily the temperature of the reaction zone. It should be known that in the embodiment of the present invention, the temperature of the reaction zone can be indirectly measured by means of a temperature field. Just as the contour line, when there is a certain temperature difference between the reaction zone and the area where the probe of the thermocouple 13 is located, the current temperature of the low temperature zone can be measured and obtained, and the current temperature of the high temperature zone can be indirectly obtained.
[0048] It should be further explained that, for example, setting the thermocouple 13 in a relatively low temperature area is conducive to extending the service life of the thermocouple 13 and other temperature measuring devices. Although there will be certain errors in indirect measurement, the impact on the measurement accuracy is generally relatively small, especially when this temperature measurement method is applied to a solution with a relatively stable temperature field. And as mentioned above, with the help of the temperature field, setting the temperature measuring device in the low temperature area can effectively protect the temperature measuring device.
[0049] It should be known that in the embodiment of the present invention, under the condition of relatively stable airflow input, the temperature field also tends to be stable.
[0050] Furthermore, a control unit is provided, wherein point I (input point) of the control unit is connected to the temperature measuring device, and outputs control of the heating device to control the temperature in a closed loop.
[0051] In addition, it should be known that in the initial stage of the operation of the hydrogen-containing tail gas treatment device, the heating device heats the temperature of the reaction zone to a predetermined temperature. During the stable operation, the oxidation reaction will generate heat, and the heating device will cool down accordingly. At the same time, since the compressed air is input in excess, the excess compressed air will take away part of the heat. Under this condition, the existence of the heating device is mainly used to adjust the relative stability of the temperature.
[0052] Regarding the control unit, it is not necessarily a controller, PLC (programmable logic controller), single-chip microcomputer, etc. It can also be a finished temperature controller. When a finished temperature controller is used, it is often only used for temperature control and cannot control other things. For other types of control elements, such as controllers, it can also control, for example, the flow of the exhaust gas intake pipe 1. In other words, if the flow of exhaust gas and compressed air is determined in a predetermined manner and no longer changes during operation, then the control can only be reflected in the temperature control of the reaction zone. Therefore, special instruments such as temperature controllers can be selected. When more types of sampling and control are required, controllers, PLCs, etc. are required.
[0053] As for the mixing degree between compressed air and hydrogen-containing tail gas, as mentioned above, it is necessary to avoid excessive mixing, but there should also be a certain degree of mixing. Figure 1 In the illustrated structure, the nozzle 14 is at a certain distance relative to the outlet of the exhaust gas intake pipe 1, which is recorded as the first distance. Figure 1 It can be seen that there is a second distance between the exhaust gas intake pipe 1 and the heating rod 12, and the second distance is roughly equivalent to the first distance. Generally, the first distance can be 0.8 to 1.5 times of the second distance, and the optimal value is 0.98 times. The compressed air ejected from the nozzle 14 will diffuse to a certain extent before contacting the hydrogen-containing exhaust gas introduced into the exhaust gas intake pipe 1, and there is a phenomenon of wrapping the hydrogen-containing exhaust gas. Although the two gases dynamically input do not produce an obvious interface after contact, the phenomenon of hydrogen-containing exhaust gas being exposed exists and is not maintained in a steady state, so that the hydrogen therein can be oxidized in an orderly manner, thereby fully oxidizing the hydrogen without excessive mixing.
[0054] In other embodiments, the two gas introduction paths are constructed by nested tubes. In this case, the length of the air intake pipe 2 inserted into the reaction chamber 5 is shorter than the length of the exhaust gas intake pipe 1 inserted into the reaction chamber, thus also showing the following Figure 1 The status shown in .
[0055] As mentioned above, due to the use of excess air, the air used to participate in the reaction is only a part of it, especially if Figure 1 The oxygen in the air in the inner layer has a lower probability of participating in the oxidation reaction, and plays a greater role in cooling. In other words, although the temperature in the reaction zone is relatively high, much higher than the boiling point of water, the reaction zone controlled in the embodiment of the present invention is relatively small, and the temperature outside the reaction zone is relatively low. The water vapor generated by the reaction exchanges heat with the relatively cold part of the excess compressed air during the upward process and liquefies. In order to prevent the liquefied water from dripping onto, for example, the heating rod 13, a water retaining eave 7 is obliquely arranged above the heating device such as the heating rod 13, and the liquid water generated by condensation flows downward through the diversion of the water retaining eave 7, avoiding, for example, the heating rod 12.
[0056] Due to the presence of the water retaining eaves 7, the discharge distance of the airflow after the reaction becomes larger, which is conducive to the removal of water vapor in the airflow after the reaction. The water retaining eaves 7 also further affect the heating of the heating rod 12, reduce the influence of thermal convection, and make the range control of the reaction zone more accurate.
[0057] Accordingly, in Figure 1 In the illustrated structure, the seat of the heating rod 12 used as the heating device is located on the right side of the insulation shell 11, and the heating body of the heating rod 12 cantilevers to the left, and the water retaining eaves 7 is also installed on the right side of the insulation shell 11 and also cantilevers to the left. The overhanging distance is greater than the overhanging distance of the heating rod 12, that is, it exceeds the heating rod 12 to the left, so that the condensed water will flow down from the left side of the water retaining eaves 7.
[0058] The water retaining eaves 7 are also similar to the partitions, except that Figure 1 An upward channel 6 is left on the left side, and the rest is sealed.
[0059] In order to better guide the condensed water downward, the water retaining eaves 7 are the same as the eaves, and have a downwardly inclined structure.
[0060] In addition, the water retaining eaves 7 may be provided with a coating, such as a super-hydrophobic coating (contact angle greater than 150°, rolling contact angle less than 10°), to facilitate the downward flow of water, thereby preventing the water from drying up to form scale spots after stopping work.
[0061] Furthermore, if a single inclined plate is used to make the water retaining eave 7, even in an inclined state, due to the Newtonian boundary friction and surface tension, some water will crawl upward along the lower surface of the water retaining eave 7. Therefore, in a preferred embodiment, the end of the water retaining eave 7 has an arc-shaped portion with the center at the bottom, such as Figure 2 The convex transition portion 18 shown in the figure increases the rolling angle, thereby facilitating the water droplets to roll downward and eliminating the phenomenon that the liquid extends the lower surface of the water eave 7 to crawl upward.
[0062] Furthermore, if Figure 2 In the structure shown, the end of the convex transition portion 18 has a knife-shaped head 17, and even if the amount of condensed water is very small, it will be enriched at the knife-shaped head 17 and drip there.
[0063] The condensed water will flow downward through the nozzle 4, for example. Then, a water outlet is provided at the bottom of the air dispersion chamber 2. The water outlet is connected to a drain pipe 16. In order to prevent air from flowing, the drain pipe 16 has a U-shaped water bend, such as Figure 1 The water bend shown in the figure has a U-shaped portion, which can achieve water sealing and avoid air leakage.
[0064] In addition, Figure 1In the illustrated structure, the gas outlet is equipped with an exhaust pipe 9, and the exhaust pipe 9 is provided with a pressure differential gauge 10; accordingly, the exhaust pipe 9 is connected to a suction device to maintain a relatively stable negative pressure in the exhaust pipe 9 to prevent hydrogen from gathering in the reaction chamber 5 and producing sufficient mixing, thereby further improving safety.
[0065] The following briefly describes a method for treating hydrogen-containing tail gas, which includes: Introducing compressed air and hydrogen-containing tail gas into a closed shell, the introduced compressed air and hydrogen-containing tail gas are dynamically mixed in a predetermined reaction zone in the shell, wherein the compressed air is an excess oxidant relative to the hydrogen-containing tail gas; The reaction zone was heated by a heating device, and the temperature of the reaction zone was maintained at 850±10°C by closed-loop control.
Claims
1. A hydrogen-containing tail gas treatment device, characterized in that: include: The shell has a reaction chamber, and the reaction chamber is provided with an air inlet at the lower end and an air outlet at the upper part; An exhaust gas inlet pipe is inserted into the reaction chamber from the air inlet and is used to introduce hydrogen-containing exhaust gas; The air intake pipe has a first configuration or a second configuration, wherein in the first configuration, the air intake pipe is nested outside the exhaust gas intake pipe and inserted into the reaction chamber to introduce compressed air into the reaction chamber; in the second configuration, the shell is provided with an air dispersion chamber at the lower side of the reaction chamber, a baffle is provided between the air dispersion chamber and the reaction chamber, the air inlet is correspondingly provided on the baffle, the air intake pipe is installed on the shell where the air dispersion chamber is located, and a flow gap or a sealed connection is left between the exhaust gas intake pipe and the air inlet. If it is a sealed connection, air holes are arranged around the air inlet; A heating device, the heating device is mounted on the housing, and the heating body included in the heating device is located in the reaction chamber to heat a predetermined reaction area, the reaction area being an exhaust area common to the exhaust gas intake pipe and the air intake pipe; A temperature measuring device, used to measure the temperature of the reaction zone; as well as The control unit is connected to the temperature measuring device and outputs a control signal to control the heating device so as to control the temperature in a closed loop.
2. The hydrogen-containing tail gas treatment device according to claim 1, characterized in that: If the air intake pipe is nested outside the exhaust gas intake pipe, the length of the air intake pipe inserted into the reaction chamber is shorter than the length of the exhaust gas intake pipe inserted into the reaction chamber.
3. The hydrogen-containing tail gas treatment device according to claim 1, characterized in that: A water retaining eave is obliquely arranged above the heating device to prevent condensed water dripping from above from contacting the heating device.
4. The hydrogen-containing tail gas treatment device according to claim 3, characterized in that: The heating device is a heating rod, the base of which is mounted on a first side of the housing defining the reaction chamber; Correspondingly, the water retaining eaves are connected from the first side to the second side and are inclined downward; The first side is opposite to the second side.
5. The hydrogen-containing tail gas treatment device according to claim 4, characterized in that: The end of the water retaining eave has an arc-shaped portion with the center of the circle downward; The end of the arc portion has a blade-shaped head.
6. The hydrogen-containing tail gas treatment device according to any one of claims 3 to 5, characterized in that: In the second configuration, a water outlet is provided at the bottom of the air dispersion chamber; The water outlet is connected with a drainage pipe; The drain pipe has a U-shaped water bend for water sealing.
7. The hydrogen-containing tail gas treatment device according to claim 1, characterized in that: The gas outlet is equipped with an exhaust pipe, and the exhaust pipe is provided with a pressure differential gauge; Correspondingly, the exhaust pipe is connected with a suction device.
8. A method for treating hydrogen-containing tail gas, characterized in that: The processing method comprises: Introducing compressed air and hydrogen-containing tail gas into a closed shell, the introduced compressed air and hydrogen-containing tail gas are dynamically mixed in a predetermined reaction zone in the shell, wherein the compressed air is an excess oxidant relative to the hydrogen-containing tail gas; The reaction zone was heated by a heating device, and the temperature of the reaction zone was maintained at 850±10°C by closed-loop control.
9. The processing method according to claim 8, characterized in that: The flow ratio of compressed air to hydrogen-containing exhaust gas is not less than 7:1 and not higher than 13:1, and is positively correlated with the hydrogen concentration in the hydrogen-containing exhaust gas.
10. The processing method according to claim 8, characterized in that: The gas after reaction in the reaction zone is extracted by forced exhaust.