A device for detecting exhaust dust in gallium nitride production and a processing system and method

Abstract

The application discloses a kind of exhaust dust detection device and processing system, method for gallium nitride production, it is related to semiconductor device technical field, including collection component and test component, the collection component includes dust collection pipe and adjusting component, the input end of the dust collection pipe is communicated with the output end of dust collection equipment, fan is equipped in the dust collection pipe, the fan is used to generate annular air curtain, the air curtain is used to divide the dust collection pipe and the test component into central region and annular edge region inside, the air curtain is also used to gather and promote the air pressure of gathering area inside the test component, the adjusting component is used to change the gathering position of the air curtain, the test component is used to receive the flue gas output by the collection component and count particulate matter in the flue gas, to test the accuracy of the number concentration data of dust obtained by component.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor devices, in particular to a gallium nitride production exhaust dust detection device and processing system and method. BACKGROUND

[0002] Gallium nitride (GaN) is the core of the third generation of semiconductor materials and plays an important role in the manufacture of optoelectronic and microwave devices. Its production process, especially the metal organic chemical vapor deposition (MOCVD) technology, will produce ultra-fine dust mainly composed of gallium nitride and various gaseous by-products in the exhaust. These dust particle sizes are mainly distributed in the sub-micron and nanometer levels, which poses a significant challenge to production process safety, environmental pollution control and equipment performance evaluation. Therefore, accurate detection of exhaust dust has become an indispensable technical link in the industry chain.

[0003] The existing monitoring schemes for dust concentration in the exhaust gas of gallium nitride production process mainly include online monitoring and offline analysis. Offline analysis usually uses gravimetric (gravimetric) methods such as tapered element oscillating microbalance (TEOM) method to determine the mass concentration by directly measuring the mass change of collected particulate matter, which has high accuracy but slow response and cannot achieve real-time monitoring. Online monitoring is mainly based on the principle of light scattering, that is, by measuring the scattered light intensity of particulate matter under laser irradiation, the number concentration and particle size distribution are inversely calculated. The commonly used equipment in this type of method is an air particle counter.

[0004] During the use of the air particle counter, negative pressure is generated inside to suck the gas at the inlet position into the detection chamber, while there is a high-intensity incident light source and a photodetector inside the detection chamber. The scattered light of the particulate matter is captured by the photodetector and converted into an electrical pulse; the number of pulses is used for counting. To ensure the accuracy and representativeness of the data obtained, the existing technology often uses isokinetic sampling and representative position sampling schemes. However, in actual operation, as the exhaust gas produced by gallium nitride production flows, the distribution of dust carried in the exhaust gas is prone to uneven distribution in time and space. If the test chamber is used to quantitatively collect the exhaust gas, although it can solve the problem of uneven distribution of dust caused by the flow of exhaust gas, dust is difficult to settle in the test chamber and the connecting pipeline during actual operation, resulting in a deviation between the number concentration obtained and the actual number concentration. SUMMARY

[0005] The present application aims to provide a gallium nitride production exhaust dust detection device and processing system and method to solve the above problems.

[0006] The present application is achieved by the following technical solutions:

[0007] A dust detection device for exhaust gas in gallium nitride production includes a collection component and a testing component. The collection component includes a dust collection pipe and an adjustment component. The input end of the dust collection pipe is connected to the output end of a dust collection device. A fan is installed inside the dust collection pipe to generate an annular air curtain. The air curtain divides the dust collection pipe and the interior of the testing component into a central region and an annular edge region. The air curtain also collects and increases the air pressure in the collection region inside the testing component. The adjustment component changes the collection position of the air curtain. The testing component receives the flue gas output from the collection component and counts the particulate matter in the flue gas. The testing component is connected to a processing component for classifying and processing the flue gas.

[0008] It also includes a control system, which is used to obtain the volume of flue gas entering the dust collection pipe and calculate the first quantity concentration of particulate matter in combination with the number of particulate matter. When the first quantity concentration is greater than or equal to a set threshold, the system controls the processing component to perform secondary treatment on the flue gas. When the first quantity concentration is less than a set value, the system controls the processing component to discharge the flue gas.

[0009] This solution uses an air curtain design to isolate the flue gas and the interior of the dust collection pipe, reducing the adhesion or settling of flue gas into the dust collection pipe. This reduces the actual dust content of the flue gas entering the test component due to dust adhesion or settling, which is lower than the dust content of the flue gas treated by the dust collection equipment, thus affecting the accuracy of the data collected by the test component.

[0010] Meanwhile, this solution also uses an air curtain to collect gas inside the test component, which affects the flow rate and particle distribution uniformity of the gas entering the test component, thereby reducing the impact of flue gas velocity and other factors on the test results.

[0011] Furthermore, the testing component includes a testing chamber and an air particle counter. The adjustment component is installed in the testing chamber. The testing chamber is connected to the output end of the dust collection pipe. The air inlet of the air particle counter is located in the testing chamber, and the air inlet of the air particle counter is coaxially arranged with the dust collection pipe.

[0012] Furthermore, the adjustment assembly includes a pump assembly and an annular groove formed on the inner wall of the test chamber away from the dust collection pipe. Several baffles are hinged to the sidewall of the annular groove, and connecting plates are provided on the sidewalls of the baffles. Several cavities are formed within the connecting plates, and deformation grooves are formed on the sidewalls of each cavity. The deformation grooves guide the deformation of the cavity sidewalls. Adjacent cavities are interconnected, and a spacer made of shape memory metal is provided at the connection point of adjacent cavities. The phase change temperature of the spacer is set in a stepped manner. A storage cavity is formed within the sidewall of the test chamber, and the storage cavity is connected to any one of the cavities. The spacer is used to change the opening degree of the connection point between adjacent cavities. The phase change temperature of the spacer increases as the distance between the spacer and the storage cavity decreases. A piston is slidably connected within the storage cavity, and the storage cavity is filled with particulate matter. The pump assembly is used to change the position of the piston, and the piston is used to push the particulate matter into or away from the cavity. The particulate matter is used to adjust and limit the shape of the connecting plate.

[0013] Furthermore, the collection assembly also includes several electrode plates, which are used to generate at least two electric fields within the dust collection tube, and these electric fields completely cancel each other out at the axial position of the dust collection tube. This design, by making the electric fields cancel each other out at the axial position of the base tube, reduces the influence of the electric field on the dust flowing in the center of the dust collection tube, thereby reducing the probability that the electric field will cause the dust to follow the gas flow through the air curtain.

[0014] Furthermore, a first filter screen is provided in the edge area of ​​the dust collection pipe, and the first filter screen is used to collect particles in the edge area of ​​the dust collection pipe.

[0015] Furthermore, the control system is also used to obtain a second quantity concentration of particles collected by the first filter, and to correct the first quantity concentration based on the second quantity concentration.

[0016] Furthermore, the dust collection pipe is also equipped with a temperature regulating component, which is used to change the temperature of the air curtain. The control system is also used to obtain the appropriate test flow rate of the air particle counter and the flow rate of the mixed gas of the air curtain and the flue gas entering the dust collection pipe. When the flow rate of the mixed gas is greater than the appropriate test flow rate, the control system controls the temperature regulating component to reduce the angle between the air curtain and the horizontal plane when it converges. When the flow rate of the mixed gas is less than the indicated test flow rate, the control system controls the temperature regulating component to increase the angle between the air curtain and the horizontal plane when it converges until the flow rate of the mixed gas is equal to the appropriate test flow rate. The control system maintains the temperature of the air curtain through the temperature regulating component.

[0017] Furthermore, the test assembly also includes a linear actuator, which is installed outside the test chamber and is used to adjust the straight-line distance between the input end of the air particle counter and the output end of the dust collection pipe. The control system is also used to adjust the position of the input end of the air particle counter while controlling the temperature control assembly to adjust the angle between the air curtain and the horizontal plane.

[0018] Furthermore, the gallium nitride production exhaust dust treatment system based on the above-mentioned gallium nitride production exhaust dust detection device includes a cooling unit, a washing unit, a detection unit, and a post-purification unit.

[0019] The cooling unit is used to reduce the temperature of the exhaust gas discharged from the gallium nitride production equipment to obtain pretreated gas;

[0020] The washing unit is used to remove dust from the pretreated gas and to wash away organometallics, volatile organic compounds and ammonia in the pretreated gas to obtain flue gas.

[0021] The detection unit is used to obtain the first quantity concentration of dust in the flue gas using a detection device, and to determine whether the first quantity concentration meets the emission requirements. When the first quantity concentration does not meet the emission requirements, the flue gas is discharged into the washing unit for secondary treatment. When the first quantity concentration meets the emission requirements, the flue gas is discharged into the post-purification unit.

[0022] The post-purification unit is used to neutralize the acidity or alkalinity of the flue gas before discharging it.

[0023] Furthermore, the gallium nitride production exhaust dust detection method based on the above-mentioned gallium nitride production exhaust dust detection device includes:

[0024] S1: Receives flue gas that has been processed by the dust collection equipment;

[0025] S2: Drives the collision of flue gas, promoting the uniform distribution of flue gas.

[0026] S3: Adjust the flow rate of the flue gas until the flow rate of the flue gas falls within the appropriate flow rate range of the air particle counter, and guide the flue gas into the air particle counter to count the dust in the flue gas.

[0027] S4: Based on the counting results, determine whether the flue gas meets the emission requirements. If the flue gas meets the emission requirements, it will be discharged into the next treatment process. If the flue gas does not meet the emission requirements, it will be discharged back into the dust collection equipment for treatment.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] 1. This invention utilizes an air curtain design to isolate the flue gas from the inner wall of the dust collection pipe, preventing dust in the flue gas from adhering to or settling inside the dust collection pipe during flow. This effectively avoids a situation where the dust concentration in the flue gas entering the air particle counter is lower than the actual dust concentration in the flue gas discharged into the device. Simultaneously, the air curtain design also guides the flue gas entering the device, reducing backflow and improving the device's efficiency. Furthermore, as the air curtain enters the test chamber, it collides with the chamber and changes direction, converging at the air inlet of the air particle counter. With each collision, the flow velocity decreases and the pressure increases at the convergence point, thus preventing excessive flue gas velocity from affecting the counting accuracy of the air particle counter.

[0030] Compared to solutions that directly install the air counter's inlet at the dust collection device's output, this invention effectively avoids the problem of unrepresentative data acquisition caused by uneven dust distribution in space and time due to dead zones and other factors during flue gas discharge. Furthermore, this solution utilizes an air curtain to reduce dust loss during flue gas flow. This also ensures the accuracy of the final data to a certain extent, even when the installation distance between the dust collection device and the testing components is far due to installation constraints, resulting in a longer flue gas flow distance. Therefore, under the same conditions, this solution has less stringent installation requirements and higher accuracy compared to existing technologies.

[0031] 2. This invention, through the design of connecting plates, partitions, and particles, utilizes temperature to adjust and monitor the bending degree of the connecting plates, and uses particles for transmission and to restrict the shape of the connecting plates. Compared with driving schemes such as hydraulic cylinders, this scheme is less prone to dust adsorption during use. Furthermore, the structure used for driving in this scheme can be impacted by the air curtain during use, thereby further reducing dust adhesion to the adjustment components and thus affecting the accuracy of the final obtained first mass fraction. In addition, the design of the connecting plates also shields the position of the baffle hinge, effectively avoiding the influence of the concave or convex position of the hinge on the air curtain flow during use.

[0032] 3. This invention also utilizes the design of an electric field and a first filter to collect and fix dust passing through the air curtain, thus compensating for the disadvantage that the air curtain cannot completely isolate gas exchange. Compared with the prior art, this solution can further improve the accuracy of the final dust quantity concentration. Compared with the solution that allows dust to directly adhere to the inner wall of the dust collection tube through the air curtain, this solution uses the first filter to collect dust. After use, only the first filter needs to be removed for replacement or cleaning to clean the dust collection tube, which is convenient and quick. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a front view of the present invention;

[0035] Figure 2 This is a side view of the present invention;

[0036] Figure 3 for Figure 1 Cross-sectional view along the AA direction;

[0037] Figure 4 for Figure 1 Cross-sectional view along the BB direction;

[0038] Figure 5 for Figure 2 Cross-sectional view along the CC direction;

[0039] Figure 6 This is a schematic diagram of the structure of the present invention;

[0040] Figure 7 This is a flowchart of the present invention.

[0041] The reference numerals in the attached diagram represent: 1. Dust collection pipe; 11. Fan; 12. First filter screen; 2. Test chamber; 21. Annular groove; 22. Baffle; 23. Connecting plate; 24. Partition; 25. Cavity; 26. Deformation groove; 27. Connecting pipe; 3. Air particle counter; 4. Cooling unit; 41. Heat exchanger; 42. Cooling tower; 5. Scrubbing unit; 51. Dust collection equipment; 52. Acidic scrubbing tower; 53. Thermal oxidizer; 6. Detection unit; 61. Three-way valve; 7. Post-purification unit; 71. Activated carbon adsorption tower. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. It should be noted that this invention is already in the actual research and development stage.

[0043] Example 1

[0044] like Figures 1 to 5 As shown, this embodiment includes a collection component and a testing component.

[0045] The collection assembly includes a dust collection pipe 1 and an adjustment assembly. The input end of the dust collection pipe 1 is connected to the output end of the dust collection device 51. A fan 11 is installed inside the dust collection pipe 1. The fan 11 is fixedly connected to the inner wall of the dust collection pipe 1 by bolts. The fan 11 is used to generate an annular air curtain. The air curtain is used to divide the dust collection pipe 1 and the interior of the test assembly into a central area and an annular edge area. The air curtain is also used to collect and increase the air pressure in the collection area inside the test assembly. The adjustment assembly is used to change the collection position of the air curtain. The test assembly is used to receive the flue gas output by the collection assembly and count the particulate matter in the flue gas.

[0046] The testing assembly includes a testing chamber 2 and an air particle counter 3. The adjustment assembly is installed in the testing chamber 2. The testing chamber 2 is connected to the output end of the dust collection pipe 1. The air inlet of the air particle counter 3 is located in the testing chamber 2, and the air inlet of the air particle counter 3 is coaxially arranged with the dust collection pipe 1.

[0047] The side wall of the test chamber 2 is provided with a connecting pipe 27. The input end of the connecting pipe 27 is connected to the test chamber 2, and the output end of the connecting pipe 27 is connected to the input end of the fan 11. The input end of the connecting pipe 27 is provided with a second filter screen.

[0048] The regulating assembly includes a pump assembly and an annular groove 21 formed on the inner wall of the test chamber 2 away from the dust collection pipe 1. In this embodiment, the pump assembly used is a water pump. Several baffles 22 are hinged to the side wall of the annular groove 21. A connecting plate 23 is provided at the hinge point between the baffles 22 and the annular groove 21. The connecting plate 23 is made of an elastic material, and the side wall of the connecting plate 23 near the baffles 22 is bonded and fixed to the baffles 22. The side wall of the connecting plate 23 near the annular cavity is bonded and fixed to the side wall of the annular cavity. Several cavities 25 are formed inside the connecting plate 23, and deformation grooves 26 are formed on the side wall of each cavity 25 away from the baffles 22. Adjacent cavities 25 are interconnected, and a connection point between adjacent cavities 25 is provided. A spacer 24 made of shape memory metal is used to change the opening of the connection between the storage cavity and the deformation cavity. The austenitic state of the spacer 24 is flattened, and it closes the connection between the cavities 25. The phase transformation temperature of the spacer 24 is set in a stepped manner. A storage cavity is opened in the side wall of the test chamber 2. The cavity 25 located at the end of the connecting plate 23 is connected to the storage cavity. In this embodiment, the smaller the distance between the spacer 24 and the storage cavity, the higher the phase transformation temperature. As the distance gradually increases, the phase transformation temperature of the spacer 24 gradually decreases. A piston is slidably connected in the storage cavity. The storage cavity on the side of the piston near the cavity 25 is filled with particulate matter. The pump assembly is connected to the storage cavity on the other side of the piston.

[0049] The test component is connected to a processing component, which is used to classify and process flue gas. In this embodiment, the processing component includes a solenoid three-way valve 61. The input end of the solenoid three-way valve 61 is connected to the output end of the storage chamber. The first output end of the solenoid three-way valve 61 is connected to the input end of the next processing device, and the second output end of the solenoid three-way valve 61 is connected to the input end of the dust collection device 51.

[0050] The system also includes a control system. In this embodiment, the control system includes a controller. The pump assembly, dust collection device 51, electromagnetic three-way valve 61, air particle counter 3, and fan 11 are all electrically connected to the controller. The controller is used to obtain the volume of flue gas discharged from the output end of the dust collection device 51 that enters the dust collection pipe 1, and calculate the first number concentration of particulate matter in combination with the number of particulate matter. When the first number concentration is greater than or equal to a set threshold, the controller controls the second output end of the electromagnetic three-way valve 61 to open, so that the flue gas re-enters the dust collection device 51 for secondary treatment of the flue gas. When the first number concentration is less than a set value, the controller controls the first output end of the electromagnetic three-way valve 61 to open and discharge the flue gas into the next processing device, so that the flue gas enters the next processing process.

[0051] The dust collection pipe 1 is also equipped with a temperature regulating component, which is used to change the temperature of the air curtain. The temperature regulating component includes a thermoelectric cooler, with a coil wound around the outer wall of the thermoelectric cooler and the coil wound around the inner wall of the dust collection pipe 1. The coil is filled with coolant. The control system also includes a temperature sensor installed in the test chamber 2. The temperature sensor is used to collect the temperature information of the gas in the test chamber 2. The controller is also used to obtain the appropriate test flow rate of the air particle counter 3 input by the user, and to obtain the flow rate of the mixture of the air curtain and the flue gas entering the dust collection pipe 1, and to determine the flow rate of the mixture. When the flow rate is greater than the suitable test flow rate, the controller controls the pump assembly and the thermoelectric cooler to operate, and calculates the angle between the baffle 22 and the inner wall of the test chamber 2 based on the temperature information, so that the angle between the baffle 22 and the inner wall of the test chamber 2 is increased, and the angle between the air curtain and the horizontal plane is reduced when the air curtain converges. When the flow rate of the mixed gas is less than the indicated test flow rate, the controller controls the pump assembly and the thermoelectric cooler to operate, so that the angle between the baffle 22 and the inner wall of the test chamber 2 is reduced, and the angle between the air curtain and the horizontal plane is increased when the air curtain converges, until the flow rate of the mixed gas is equal to the suitable test flow rate. The controller maintains the temperature of the air curtain through the temperature adjustment component.

[0052] The controller is also used to adjust the flow rate of the air curtain according to the flow rate of the flue gas at the output end of the dust collection equipment 51.

[0053] The test assembly also includes a linear actuator (not shown in the figure). In this embodiment, the linear actuator is an electric rod. The electric rod is fixedly connected to the outer wall of the test chamber 2 by bolts, and the output end of the electric rod is fixedly connected to the air particle counter 3 by bolts. The linear actuator is installed on the outside of the test chamber 2, and the linear actuator is used to adjust the straight-line distance between the input end of the air particle counter 3 and the output end of the dust collection pipe 1.

[0054] The controller is also used to adjust the position of the input end of the air particle counter 3 while controlling the temperature control component to adjust the angle between the air curtain and the horizontal plane during the air curtain convergence.

[0055] The specific implementation method is as follows: During the use of this device, the fan 11 operates, spraying pressurized and pure gas into the dust collection pipe 1 and the test chamber 2. The design of the connecting pipe 27 allows part of the gas output by the fan 11 to return to the fan 11, avoiding the gas output by the fan 11 from causing a sudden increase in air pressure in the test chamber 2, which could lead to a safety accident. The gas flows along the inner wall of the dust collection pipe 1 and the top, bottom, and side walls of the test chamber 2, forming an annular air curtain. The flue gas discharged during the gallium nitride production process is treated by the dust collection equipment 51 and then intermittently discharged into the dust collection pipe 1. At this time, due to the formation of the air curtain, most of the flue gas is prevented from approaching the dust collection pipe 1 and the inner wall of the test chamber 2, thereby reducing the probability that the dust particles carried by the flue gas will settle or adhere to the inner wall of the dust collection pipe 1 during the flue gas flow.

[0056] After the air curtain enters the test chamber 2, it impacts the side wall of the annular groove 21 away from the baffle 22. Guided by the annular cavity, the air curtain adheres to the side wall and bottom wall of the annular cavity. After the air curtain passes the bottom wall of the annular cavity, the direction of the air curtain reverses. After the air curtain passes the baffle 22, it continues to move along the side wall of the baffle 22 and finally converges and collides in the test chamber 2. At the moment of collision of the air curtains in various directions, most of the kinetic energy of the air curtain is converted into pressure potential energy, that is, the speed of the gas flow that makes up the air curtain drops rapidly, and a local high pressure appears in the convergence area.

[0057] Simultaneously, during the aforementioned process, the air particle counter 3 operates continuously. By generating negative pressure at the air inlet, it draws gas from the inlet into the air particle counter 3, thereby counting dust particles inside the test chamber 2. At this time, the pressure difference between the area around the air inlet and the location where the air curtain converges is much higher than at other locations inside the test chamber 2. Under the influence of this pressure difference, the gas at the location where the air curtain converges is more likely to enter the air particle counter 3. Furthermore, due to the impact of the air curtain on the inner wall of the annular groove 21, dust is stirred up inside the test chamber 2, reducing dust settling or adhesion to the inner wall of the test chamber 2. This results in a lower number of particles being counted, thus affecting the accuracy of the final dust concentration.

[0058] While obtaining the approximate number of dust particles inside the test chamber 2 through the air particle counter 3, the controller obtains the volume of the flue gas discharged into the dust collection pipe 1 through the dust collection device 51, thereby obtaining the first quantity concentration.

[0059] The first quantity concentration is then compared and calculated with the set threshold (i.e., the quantity concentration of the emission standard that the flue gas needs to meet). When the first quantity concentration is greater than or equal to the set threshold, the second output end of the solenoid three-way valve 61 is opened, so that the flue gas re-enters the dust collection device 51 for secondary treatment. When the first quantity concentration is less than the set value, the first output end of the solenoid three-way valve 61 is opened to discharge the flue gas into the next treatment device, so that the flue gas enters the next treatment process.

[0060] During the above process, the controller can also continuously obtain the flow rate of the flue gas discharged into the dust collection pipe 1 through the dust collection device 51. When the flow rate of the flue gas is not less than the flow rate of the air curtain, and the flow rate of the flue gas is less than the flow rate of the air curtain but the difference between the two is not greater than the set value, the air curtain is difficult to achieve the effect of isolating the flue gas and the inside of the dust collection pipe 1. At this time, the controller controls the fan 11 to increase the working power to ensure that the flow rate of the air curtain is always greater than that of the flue gas, and the difference between the two is always greater than the set value.

[0061] As the air curtain velocity increases, the velocity also increases after the air curtain impacts the annular groove 21. If the angle of the baffle 22 is maintained so that the air curtain gathers in the original position, the velocity of the gathered air curtain along the radial direction of the test chamber 2 increases, the gas velocity in the gathering area rises, and the gas velocity entering the air particle counter 3 rises, affecting the accuracy of the air particle counter 3.

[0062] At this time, the controller controls the thermoelectric cooler to work, while the temperature sensor continuously acquires the temperature information of the gas in the detection chamber. This causes the thermoelectric cooler to cool the coolant inside the coil, and the coil to cool the gas inside the dust collection pipe 1. The cooled air curtain acts on the annular groove 21 and the baffle 22, thereby cooling the baffle 22 and the connecting plate 23 above it. As the temperature of the connecting plate 23 decreases, the temperature of the spacer 24 inside the connecting plate 23 also decreases. When the temperature is lower than the phase transformation temperature of the spacer 24, the spacer 24 transforms from the austenitic state to the martensitic state. At the same time, the controller controls the pump assembly to work, and the pump assembly pumps liquid into the storage chamber. The liquid drives the active... During the plugging motion, compared to the austenitic state partition 24, the martensitic state partition 24 has lower hardness, making it more difficult for particles to deform the austenitic state partition 24, but easier to deform the martensitic state partition 24. The cavities 25 on both sides of the martensitic state partition 24 are connected, allowing particles to enter the corresponding cavities 25. As the particles enter, they push the cavity 25 to deform. Due to the design of the deformation groove 26, stress concentration occurs on the bottom wall of the deformation groove 26, and the side wall of the cavity 25 deforms along the deformation groove 26. The connecting plate 23 bends, thereby changing the angle between the baffle 22 and the horizontal plane, so that the angle between the baffle 22 and the horizontal plane gradually increases. Since the bending degree of the connecting plate 23 is affected by the state of the partition 24, the controller can determine the number of partitions 24 in the martensitic state based on the internal temperature of the dust collection pipe 1, and then determine the bending state of the connecting plate 23, thereby determining the angle between the baffle 22 and the horizontal plane. Since the position of the air curtain gathering is basically determined by the angle before the air curtain gathers, and the angle before the air curtain gathers is determined by the angle of the baffle 22, the position of the air curtain gathering after impacting the annular groove 21 can be determined based on the internal temperature of the dust collection pipe 1.

[0063] Once the air curtain reaches the appropriate position, the controller readjusts the operating state of the semiconductor cooling chip, causing all the partitions 24 to return to above the phase change temperature. This ensures that all the partitions 24 are restored to the state of closing the connection between the cavities 25. Subsequently, the pump assembly re-pumps the liquid in the storage chamber, and the piston gradually resets. A negative pressure appears on the side of the piston away from the liquid, causing the particles at the connection between the storage chamber and the cavity 25 to reset due to the negative pressure. At the same time, the air pressure in the cavity 25 is reduced. The gas in each cavity 25 flows through the gaps between the partitions 24 and the adjacent sidewalls, resulting in a negative pressure state in each cavity 25. Under the action of air pressure, the particles are squeezed against each other. Due to the friction between the particles, the particles are difficult to displace under the action of external force, thereby reducing the probability of deformation of the connecting plate 23 under the action of the air curtain. This, along with the damping hinge between the baffle 22 and the annular groove 21, simultaneously fixes the angle of the baffle 22.

[0064] This results in a larger angle at which the air curtains converge and collide after flowing along the baffle 22, thus converting more of the air curtains' kinetic energy into pressure potential energy. This reduces the probability that the air particle counter 3 will be affected by the excessively fast flow velocity after the air curtains converge.

[0065] At the same time, the controller controls the linear actuator to adjust the position of the air inlet of the air particle counter 3 so that the air inlet of the air particle counter 3 can basically coincide with the position of the air curtain convergence.

[0066] In this scheme, particles and pump components are used to adjust the deformation state of the connecting plate 23 and fix its shape. Compared with the gas-driven scheme, the particle compression is small in this scheme, and the stability of the connected plate 23 after deformation is high, making the connected plate 23 and the baffle 22 less likely to sway under the action of the air curtain. At the same time, compared with the traditional liquid-driven scheme, after the shape of the connected plate 23 is adjusted, the particles inside the connected plate 23 are less likely to slide under the action of external force, further improving the stability of the baffle 22.

[0067] Meanwhile, conventional solutions using linear drives such as pneumatic cylinders, electric cylinders, and hydraulic cylinders inevitably attract dust from the surrounding gas due to static electricity and oil stains during cylinder operation, thus affecting the accuracy of the first quantity concentration. Even with an elastic protective sleeve on the outside of the cylinder, static electricity and oil stains generated during cylinder movement can easily be transferred to the protective sleeve, causing dust to adhere to it. This solution can effectively reduce the adsorption of dust from the surrounding gas by static electricity or oil stains during the operation of the regulating component, thereby reducing the impact of the regulating component on the first quantity concentration of dust.

[0068] Meanwhile, compared to the initial state where the angle between the air curtains is close to 180 degrees through the baffle 22, although this scheme can convert most of the kinetic energy of the air curtain into pressure potential energy to reduce the impact of gas flow velocity on the accuracy of the data collected by the air particle counter 3, in the above case, the air curtain often flows along the inner wall of the test chamber 2 during the flow process, making it difficult to drive the flow in the central area of ​​the test chamber 2. This results in uneven dust distribution in various positions of the test chamber 2, thus making the gas at the air inlet of the air particle counter 3 unrepresentative.

[0069] Simultaneously, the baffle 22 can ensure that any two airflows symmetrical along the axis of the annular groove 21 within the airflow forming the air curtain are maintained at a 90-degree angle. This allows the directional kinetic energy of the air curtain to be more completely converted into turbulent energy, thereby promoting the mixing of dust in the air curtain and flue gas, promoting the uniform distribution of dust within the test chamber 2, and significantly improving the representativeness of the data obtained by the air particle counter 3. However, during the implementation of the above scheme, the flow velocity after the air curtain converges cannot be adjusted. When facing flue gas with excessively high flow velocity, the converged gas velocity may be too fast, affecting the air particle counter 3.

[0070] Therefore, this solution uses the design of baffle 22 and connecting plate 23 to adjust the angle of baffle 22 by using particulate matter and pump assembly, thereby adjusting the included angle between the air curtains during collection. This achieves a balance between reducing the gas flow rate at the air inlet of the air particle counter 3 and improving the uniformity of dust distribution, ensuring that the gas entering the air particle counter 3 has less impact on the accuracy and representativeness of the data acquisition of the air particle counter 3.

[0071] Meanwhile, the temperature control component in this solution adjusts the temperature of the air particle counter 3 during the adjustment of the angle of the baffle 22. Since the exhaust gas temperature during gallium nitride processing is high, it often exceeds the recommended temperature range for the air particle counter 3 (the recommended range is often between 15°C and 35°C). This solution effectively reduces the impact of high-temperature flue gas on the internal structure of the air particle counter 3 by cooling the inside of the dust collection pipe 1.

[0072] This solution utilizes an air curtain design to significantly reduce the adhesion of dust from the flue gas to the dust collection pipe 1 and the inner wall of the test chamber 2. Compared to existing technologies that only use a smooth-sided test chamber 2, this solution reduces dust adhesion to the inner wall, thus minimizing its impact on the accuracy of data collected by the air particle counter 3. Furthermore, this solution uses the deformation of the connecting plate 23 to adjust the angle of the air curtain via the baffle 22. Simultaneously, the connecting plate 23 can fill the recesses and protrusions of the baffle 22 hinge through its own elastic deformation, reducing the disruption of laminar flow caused by the concave or convex hinges when the air curtain passes through the hinged position of the baffle 22. This prevents the air curtain from stratifying and ultimately makes it difficult for the air curtain to converge and collide at the air inlet of the air particle counter 3.

[0073] Example 2

[0074] The difference from the above embodiments is that the collection assembly further includes several electrode plates. In this embodiment, two electrode plates are provided, one of which is installed on the outer top wall of the dust collection pipe 1, and the other electrode plate is installed on the outer bottom wall of the dust collection pipe 1. The electric field strengths generated by the two electrode plates are the same and the directions are opposite. The electrode plates are used to generate at least two electric fields within the dust collection pipe 1, and the electric fields completely cancel each other out at the axial position of the dust collection pipe 1. A first filter screen 12 is provided in the edge region of the dust collection pipe 1. The first filter screen 12 is bonded and fixed to the inner sidewall of the dust collection pipe 1. The first filter screen 12 is used to collect particles in the edge region of the dust collection pipe 1.

[0075] The control system also includes a laser scattering sensor, which is fixedly connected to the inner wall of the dust collection pipe 1 by bolts and electrically connected to the controller. The laser scattering sensor is used to obtain the second quantity concentration of particles collected by the first filter screen 12, and the controller corrects the first quantity concentration based on the second quantity concentration.

[0076] The specific implementation method is as follows: When the flue gas passes through the dust collection pipe 1, if the flue gas flow rate at the output end of the dust collection device 51 suddenly increases, the flow rate of the air curtain is insufficient to block the flue gas from entering the edge area. At the same time, since the air curtain cannot completely block the gas exchange between the central area and the edge area, some dust will inevitably enter the edge area when the flue gas passes through the dust collection pipe 1.

[0077] Therefore, during the use of this device, two electric fields with opposite directions can be provided to the dust collection tube 1 through the electrode plate. The electric field causes the dust particles to become charged and drives the charged dust to move towards the electrode plate, and finally be captured by the first filter 12, thereby achieving relative fixation of the dust position.

[0078] Compared to existing technologies, this solution can prevent dust adhering to the inner wall of the dust collection pipe 1 from being stirred up by the flue gas during the next flue gas introduction, thus preventing the dust concentration at the input end of the flue gas from being lower than the dust concentration flowing into the test chamber 2, thereby affecting the accuracy of the final collected data.

[0079] Meanwhile, as the dust falls into the first filter 12, the laser scattering sensor continuously collects the second quantity concentration of the dust. Since the size of the dust collection pipe 1 and the position of the air curtain are known, i.e. the volume of the edge area is known, the second quantity concentration can be used to roughly obtain the amount of dust entering the edge area. After adding the amount of dust in the edge area to the amount of dust in the test chamber 2, and combining it with the volume of the flue gas discharged into the device, the first quantity concentration can be corrected. At this time, the accuracy of the first quantity concentration is higher, effectively avoiding the impact of some dust entering the edge area on the accuracy of the first quantity concentration.

[0080] Example 3

[0081] As attached Figure 6 As shown, the difference from the above embodiment is that: a gallium nitride production exhaust dust treatment system based on the above-mentioned gallium nitride production exhaust dust detection device is also disclosed, including a cooling unit 4, a washing unit 5, a detection unit 6 and a post-purification unit 7.

[0082] The cooling unit 4 is used to reduce the temperature of the exhaust gas discharged from the gallium nitride production equipment to obtain pretreated gas. The cooling unit 4 includes a heat exchanger 41 and a cooling tower 42. The output end and input end of the cooling tower 42 are both connected to the heat exchanger 41. The input end of the heat exchanger 41 is connected to the exhaust gas output end of the gallium nitride production equipment. During use, the coolant enters the heat exchanger 41 and cools the exhaust gas passing through the heat exchanger 41. The coolant after heat exchange is completed enters the cooling tower 42 again for cooling and then enters the next heat exchange process.

[0083] The washing unit 5 is used to remove dust from the pretreated gas and to wash away organic metals, volatile organic compounds, and ammonia from the pretreated gas to obtain flue gas. The washing unit 5 includes an acidic scrubbing tower 52, a thermal oxidizer 53, and a dust collection device 51.

[0084] During operation, the pretreated gas passes through a dust collection device 51, which uses PTFE-coated filter media to capture most of the dust carried by the pretreated gas. The gas is then discharged into an acid scrubbing tower 52, which is filled with polypropylene Pall rings and uses sulfuric acid solution as the absorbent. The acid scrubbing tower 52 treats alkaline gases such as ammonia in the pretreated gas. The gas is then discharged into a thermal oxidizer 53, where it is heated to remove organic metals and volatile organic compounds, ultimately yielding the flue gas.

[0085] The detection unit 6 is used to obtain the first quantity concentration of dust in the flue gas using a detection device, and to determine whether the first quantity concentration meets the emission requirements. When the first quantity concentration does not meet the emission requirements, the flue gas is discharged into the washing unit 5 for secondary treatment. When the first quantity concentration meets the emission requirements, the flue gas is discharged into the post-purification unit 7.

[0086] The post-purification unit 7 is used to neutralize the acidity or alkalinity of the flue gas before discharging it. The post-purification unit 7 includes an activated carbon adsorption tower 71, whose packing material is honeycomb activated carbon impregnated with an acidic reagent, to adsorb residual alkaline gases and organometallic substances in the flue gas.

[0087] Example 4

[0088] As attached Figure 7 As shown, the difference from the above embodiments is that a method for detecting exhaust dust in gallium nitride production based on the above-described exhaust dust detection device for gallium nitride production is also disclosed, including:

[0089] S1: Receives flue gas that has been processed by dust collection equipment 51;

[0090] S2: Drives the collision of flue gas, promoting the uniform distribution of flue gas.

[0091] S3: Adjust the flow rate of the flue gas until the flow rate of the flue gas falls within the appropriate flow rate range of the air particle counter 3, and guide the flue gas into the air particle counter 3 to count the dust in the flue gas using the air particle counter 3.

[0092] S4: Based on the counting results, determine whether the flue gas meets the emission requirements. If the flue gas meets the emission requirements, it will be discharged into the next treatment process. If the flue gas does not meet the emission requirements, it will be discharged back into the dust collection equipment 51 for treatment.

[0093] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An exhaust dust detection device for gallium nitride production, comprising a collection component and a testing component, characterized in that: The collection component includes a dust collection pipe (1) and an adjustment component. The input end of the dust collection pipe (1) is connected to the output end of the dust collection device (51). A fan (11) is provided inside the dust collection pipe (1). The fan (11) is used to generate an annular air curtain. The air curtain is used to divide the dust collection pipe (1) and the interior of the test component into a central area and an annular edge area. The air curtain is also used to collect and increase the air pressure in the collection area inside the test component. The adjustment component is used to change the collection position of the air curtain. The test component is used to receive the flue gas output by the collection component and count the particulate matter in the flue gas. The test component is connected to a processing component. The processing component is used to classify and process the flue gas. The test assembly includes a test chamber (2) and an air particle counter (3). The adjustment assembly is installed in the test chamber (2). The test chamber (2) is connected to the output end of the dust collection pipe (1). The air inlet of the air particle counter (3) is located in the test chamber (2), and the air inlet of the air particle counter (3) is coaxially arranged with the dust collection pipe (1). The regulating assembly includes a pump assembly and an annular groove (21) formed on the inner wall of the test chamber (2) away from the dust collection pipe (1). Several baffles (22) are hinged to the side wall of the annular groove (21), and connecting plates (23) are provided on the side walls of the baffles (22). Several cavities (25) are formed within the connecting plates (23), and deformation grooves (26) are formed on the side walls of each cavity (25). The deformation grooves (26) are used to guide the deformation of the side walls of the cavities (25). Adjacent cavities (25) are interconnected, and a memory metal partition (24) is provided at the connection point of adjacent cavities (25). The phase change temperature of the partition (24) is set in a stepped manner. A storage cavity is opened in the side wall of the chamber (2), which is connected to any of the cavities (25). The partition (24) is used to change the opening of the connection between adjacent cavities. The phase change temperature of the partition (24) increases as the distance between the partition (24) and the storage cavity decreases. A piston is slidably connected in the storage cavity. The storage cavity is filled with particulate matter. The pump assembly is used to change the position of the piston. The piston is used to push the particulate matter into or away from the cavity (25). The particulate matter is used to adjust and limit the shape of the connecting plate (23). A temperature regulating component is also provided in the dust collection pipe (1). The temperature regulating component is used to change the temperature of the air curtain. It also includes a control system, which is used to obtain the appropriate test flow rate of the air particle counter (3) and the flow rate of the mixed gas of the air curtain and the flue gas entering the dust collection pipe (1). When the flow rate of the mixed gas is greater than the appropriate test flow rate, the control system reduces the angle between the air curtain and the horizontal plane when the air curtain converges by controlling the temperature adjustment component. When the flow rate of the mixed gas is less than the indicated test flow rate, the control system increases the angle between the air curtain and the horizontal plane when the air curtain converges by controlling the temperature adjustment component until the flow rate of the mixed gas is equal to the appropriate test flow rate. The control system maintains the temperature of the air curtain by controlling the temperature adjustment component. The control system is used to obtain the volume of flue gas entering the dust collection pipe (1) and calculate the first number concentration of particulate matter in combination with the number of particulate matter. When the first number concentration is greater than or equal to a set threshold, the control system controls the processing component to perform secondary treatment on the flue gas. When the first number concentration is less than a set value, the control system controls the processing component to discharge the flue gas.

2. The exhaust dust detection device for gallium nitride production according to claim 1, characterized in that: The collection assembly also includes several electrode plates, which are used to generate at least two electric fields in the dust collection tube (1), and the electric fields completely cancel each other out at the axial position of the dust collection tube (1).

3. The exhaust dust detection device for gallium nitride production according to claim 2, characterized in that: A first filter (12) is provided in the edge area of ​​the dust collection pipe (1), and the first filter (12) is used to collect particles in the edge area of ​​the dust collection pipe (1).

4. The exhaust dust detection device for gallium nitride production according to claim 3, characterized in that: The control system is also used to obtain a second quantity concentration of particles collected by the first filter (12) and to correct the first quantity concentration based on the second quantity concentration.

5. The exhaust dust detection device for gallium nitride production according to claim 1, characterized in that: The test assembly also includes a linear actuator, which is installed outside the test chamber (2) and is used to adjust the straight distance between the input end of the air particle counter (3) and the output end of the dust collection pipe (1). The control system is also used to adjust the position of the input end of the air particle counter (3) while controlling the temperature control assembly to adjust the angle between the air curtain and the horizontal plane.

6. A gallium nitride production exhaust dust treatment system based on the exhaust dust detection device for gallium nitride production according to any one of claims 1-5, characterized in that: It includes a cooling unit (4), a washing unit (5), a detection unit (6), and a post-purification unit (7); The cooling unit (4) is used to reduce the temperature of the exhaust gas discharged from the gallium nitride production equipment to obtain pretreated gas; The washing unit (5) is used to remove dust from the pretreated gas and to wash away organic metals, volatile organic compounds and ammonia in the pretreated gas to obtain flue gas. The detection unit (6) is used to obtain the first quantity concentration of dust in the flue gas using a detection device, and to determine whether the first quantity concentration meets the emission requirements. When the first quantity concentration does not meet the emission requirements, the flue gas is discharged into the washing unit (5) for secondary treatment. When the first quantity concentration meets the emission requirements, the flue gas is discharged into the post-purification unit (7). The post-purification unit (7) is used to neutralize the acidity or alkalinity of the flue gas before discharging it.

7. A detection method based on an exhaust dust detection device for gallium nitride production according to any one of claims 1-5, characterized in that: include: S1: Receives flue gas that has been processed by the dust collection device (51); S2: Drives the collision of flue gas, promoting the uniform distribution of flue gas. S3: Adjust the flow rate of the flue gas until the flow rate of the flue gas falls within the appropriate flow rate range of the air particle counter (3), and guide the flue gas into the air particle counter (3) for counting; S4: Based on the counting results, determine whether the flue gas meets the emission requirements. If the flue gas meets the emission requirements, it will be discharged into the next processing flow. If the flue gas does not meet the emission requirements, it will be discharged into the dust collection equipment (51) for processing again.

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