A gas detection pre-treatment device for confined spaces

Abstract

The application provides a gas detection pretreatment device for a limited space, and belongs to the technical field of safety monitoring of limited space operation and industrial gas detection pretreatment. The device comprises a stable pressure filter assembly and a gas mixing box. The gas mixing box is installed at the front end of the stable pressure filter assembly, and the input port of the gas mixing box is in communication with the inside of the gas to be detected. The stable pressure filter assembly and the gas mixing box are arranged to integrate various filter modules into the shell. After filtration, the gas can be output to the detection equipment in a constant pressure mode. The device can be directly fixed in the narrow area outside the limited space such as a sewage well and a cable trench by a cable tie and adhesive, without the need of an additional large-size installation platform. The device solves the problem that the traditional pretreatment equipment is large in size and cannot be laid out in a narrow downhole, and is perfectly adapted to the operation environment of limited space import and export narrowness and limited equipment placement space.

Description

Technical Field

[0001] This invention relates to the fields of safety monitoring in confined space operations and pretreatment technology for industrial gas detection, and particularly to a gas detection pretreatment device for confined spaces. Background Technology

[0002] Underground confined spaces such as municipal sewage wells, power cable trenches, and enclosed water supply and drainage ditches are high-risk areas for safe production. These spaces are enclosed and have extremely poor ventilation. The sludge and sewage in these spaces continuously release toxic and flammable gases such as hydrogen sulfide, sulfur dioxide, volatile organic acids, and methane.

[0003] Industrial and municipal confined spaces typically have three main characteristics: narrow entrances and exits, extremely poor internal ventilation, bidirectional fluctuations in air pressure, and harsh gas media. Firstly, the space has a small internal diameter, leaving no extra space for equipment installation, and the space for personnel operation and equipment placement is extremely limited. Secondly, the internal gas mixture contains suspended silt and dust, sewage droplets, organic oil mist, hydrogen sulfide and sulfuric acid dioxide corrosive gases, and saturated water vapor. It is prone to condensation in low-temperature environments, and the different gases have different densities, which can easily lead to stratification and aggregation. Third, the air pressure inside the space fluctuates continuously due to the influence of water level, ventilation, and underground airflow, and the water at the bottom is prone to backflow into the detection equipment due to the negative pressure of the air pump; Existing gas detection pretreatment devices occupy a large area and cannot be installed in limited spaces. At the same time, traditional single-stage filter cartridges simultaneously filter droplets, oil mist, dust, and water vapor. Impurities mix and accumulate, clogging the filter cartridges. The filter cartridge replacement cycle is only 1-3 days, resulting in extremely high maintenance costs. Furthermore, there is no acid gas neutralization structure, and the electrochemical gas probe is easily corroded and rendered unusable.

[0004] Therefore, this application provides a gas detection pretreatment device for confined spaces to meet the requirements. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a gas detection pretreatment device for confined spaces. By setting up a pressure-stabilizing filter assembly and a mixing box, various different filter modules are integrated into the housing. After filtration, the gas can be output to the detection equipment at a constant pressure. Moreover, the device can be directly fixed to narrow areas outside confined spaces such as sewage wells and cable trenches with cable ties and adhesives, without the need for an additional large-sized installation platform. This solves the problem that traditional pretreatment equipment is bulky and cannot be installed in narrow wells, and is perfectly adapted to the working environment where the inlet and outlet of the confined space are narrow and the equipment placement space is limited.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A gas detection pretreatment device for confined spaces includes a pressure-stabilizing filter assembly and a mixing chamber. The mixing chamber is installed at the front end of the pressure-stabilizing filter assembly, and its input port is connected to the interior of the gas to be tested. The pressure-stabilizing filter assembly includes a housing. An air inlet pipe is sealed and fixedly connected to the front end of the housing, and a receiving shell is sealed and fixedly installed at the bottom end of the housing. A separation cylinder is provided inside the receiving shell. A sealing partition is sealed and fixedly connected to the top outer wall of the separation cylinder, and the sealing partition is sealed and fixedly connected to the inner wall of the housing. An air inlet channel is provided between the separation cylinder and the air inlet pipe, and the gas input through the air inlet pipe can only enter the air inlet channel.

[0007] Optionally, a fiberglass pleated coarse filter layer is fixedly installed on the inner wall of the separation cylinder. The fiberglass pleated coarse filter layer is provided in multiple sets and is evenly distributed on the peripheral wall of the separation cylinder. Multiple sets of limiting strips are evenly fixedly installed on the inner wall of the separation cylinder. The same spiral cooling pipe is fixedly installed on the inner wall of the multiple sets of limiting strips. Both ends of the spiral cooling pipe are sealed and penetrate through the side wall of the separation cylinder. A gas cylinder is fixedly installed on the outer wall of the separation cylinder. Both ends of the spiral cooling pipe are sealed and connected to the two ports of the gas cylinder. A guide groove is opened at the top of the spiral cooling pipe, and the guide groove connecting the spiral cooling pipe to the bottom port of the gas cylinder is twisted at 90°.

[0008] Optionally, a dust removal filter element is fixedly installed on the inner wall of the separation cylinder. The dust removal filter element is provided in multiple sets and is distributed in a linear array inside the separation cylinder. A breathable bag is fixedly installed on the inner wall of the top of the separation cylinder. The breathable bag is filled with solid neutralizing filter material. A sludge discharge port is opened at the bottom of the separation cylinder and is connected to the inside of the receiving shell.

[0009] Optionally, a top support shell is sealed and fixedly connected to the top port of the housing. A screw is fixedly installed on the inner wall of the middle part of the top support shell. A connecting column is fixedly installed on the inner wall of the middle part of the screw. A positioning nut is engaged on the screw. A pressure stabilizing shell is sealed and fixedly installed on the inner wall of the housing. Four sets of air inlets are evenly opened on the outer wall of the pressure stabilizing shell. The top opening of the separator cylinder is connected to the air inlets, and the gas in the separator cylinder can only enter the pressure stabilizing shell through the air inlets.

[0010] Optionally, a sliding column is slidably installed on the top inner wall of the voltage regulator housing, an elastic sealing membrane is fixedly installed on the outer wall of the middle part of the sliding column, and the outer wall of the elastic sealing membrane is fixedly connected to the inner wall of the housing. The connecting column slides through the top of the sliding column, a spring is fixedly installed on the top of the sliding column, and the other end of the spring is fixedly connected to the inner wall of the top support housing. A sealing ring is sleeved on the outer wall of the sliding column, and the sealing ring contacts the inner wall of the voltage regulator housing. An air vent is opened at the bottom of the voltage regulator housing, and a blocking rod is fixedly installed at the bottom of the sliding column, and the blocking rod is used in conjunction with the air vent.

[0011] Optionally, a hydrophobic and breathable membrane is fixedly installed on the inner wall of the air inlet, and a dehumidifying packing is installed inside the pressure stabilizing shell, with the plug rod sliding through the dehumidifying packing.

[0012] Optionally, a detection tube is sealed and fixedly connected to the end port of the housing, and a detection device is connected to the external of the detection tube. The detection tube is connected to the air outlet, and a pressure gauge is fixedly installed on the top of the end of the housing, and the pressure gauge can detect the air pressure inside the detection tube.

[0013] Optionally, the mixing chamber has a mixing channel inside. A gas supply pipe is fixedly installed at the end of the mixing channel and is sealed to the inlet pipe. A single-pass pipe is fixedly installed at the front end of the mixing channel. Three sets of air vents are evenly fixedly installed on the side wall of the single-pass pipe. A suction hose is fixedly installed at the end of the air vent, and the three sets of suction hoses are located at the upper, middle, and lower parts of the gas to be tested, respectively. An anti-winding filter is fixedly installed on the inner wall of the front end of the suction hose. An air pump is fixedly installed on the inner wall of the front end of the mixing channel. The input end of the air pump is connected to the inside of the single-pass pipe, and the output end of the air pump is connected to the inside of the mixing channel. Multiple sets of mixing blades are evenly fixedly installed on the inner wall of the mixing channel.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: In the above solution, by setting up a pressure-stabilizing filter assembly and a mixing box, various different filter modules are integrated into the housing. After filtration, the gas can be output to the detection equipment at a constant pressure. Moreover, this device can be directly fixed to narrow areas outside confined spaces such as sewage wells and cable trenches with cable ties and adhesives, without the need for an additional large-size installation platform. This solves the problem that traditional pretreatment equipment is bulky and cannot be installed in narrow wells, and is perfectly adapted to working environments with narrow inlet and outlet and limited equipment placement space. The mixing chamber is equipped with three independent suction hoses at the front end, which can be extended into the upper, middle and lower layers of a limited space to simultaneously extract gas. This avoids the defects of stratified accumulation of harmful gases of different densities such as hydrogen sulfide and methane, and the inability of single-point sampling to represent the overall gas concentration of the space. At the same time, the suction hoses are equipped with anti-tangling filters to intercept silt, weeds and fibrous materials in advance, avoiding pipeline blockage and ensuring long-term continuous sampling. After the airflow passes through the mixing channel with multiple sets of mixing blades, the gas in each layer is fully homogeneously mixed through airflow division, merging and turbulence disturbance, eliminating local gas concentration deviations. The components of the gas to be tested sent to the rear gas filtration unit are uniform, which greatly improves the accuracy of gas detection data. Attached Figure Description

[0015] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0016] Figure 1This is a three-dimensional structural diagram of a gas detection and pretreatment device for use in a confined space. Figure 2 This is a schematic diagram of the assembly of various pipes on the mixing chamber; Figure 3 This is a schematic diagram of the internal structure of the mixing chamber; Figure 4 This is a schematic diagram of the assembly of the mixing channel and the mixing section blades; Figure 5 This is a schematic diagram of the pressure-stabilizing air filtration assembly; Figure 6 This is a cross-sectional view of the pressure-stabilizing filter assembly; Figure 7 This is a connection diagram of the air outlet, the detection tube, and the pressure gauge; Figure 8 This is a schematic diagram of the internal structure of the separator. Figure 9 This is a schematic diagram of the assembly of solid neutralizing filter material inside the breathable bag; Figure 10 for Figure 9 Enlarged view of point A in the middle; Figure 11 This is a cross-sectional view of the voltage regulator housing; Figure 12 for Figure 11 Enlarged view of point B in the middle; Figure 13 This is a schematic diagram of the structure inside the top support shell.

[0017] Figure label: Pressure stabilizing filter assembly 100, housing 110, sealing partition 111, air inlet pipe 112, receiving shell 113, detection pipe 114, pressure gauge 115, separator 120, air inlet channel 121, fiberglass pleated coarse filter layer 122, limiting strip 123, spiral cooling pipe 124, guide groove 125, gas cylinder 126, waste outlet 127, dust collector filter element 130, breathable bag 131, solid neutralizing filter media 132, top support shell 140, screw 141, connecting Column 142, positioning nut 143, sliding column 144, elastic sealing membrane 145, spring 146, plug rod 147, sealing ring 148, pressure stabilizing shell 150, air inlet 151, hydrophobic and breathable membrane 152, air outlet 153, dehumidifying packing 154, mixing box 200, air delivery pipe 210, single-pass pipe 220, ventilation pipe 221, suction hose 222, anti-winding filter 223, air pump 230, mixing channel 240, mixing section blade 250.

[0018] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0019] The gas detection and pretreatment device for confined spaces provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0020] like Figures 1 to 13 As shown, an embodiment of the present invention provides a gas detection pretreatment device for a confined space, including a pressure-stabilizing filtration assembly 100 and a mixing chamber 200. The mixing chamber 200 is installed at the front end of the pressure-stabilizing filtration assembly 100, and its input port is connected to the interior of the gas to be tested. The pressure-stabilizing filtration assembly 100 includes a housing 110. An inlet pipe 112 is sealed and fixedly connected to the front end of the housing 110, and a receiving shell 113 is sealed and fixedly installed at the bottom end of the housing 110. The part is provided with a separator cylinder 120, and a receiving shell 113 can receive the impurities separated in the separator cylinder 120. A sealing partition 111 is sealed and fixed to the outer wall of the top of the separator cylinder 120, and the sealing partition 111 is sealed and fixed to the inner wall of the housing 110. The sealing partition 111 plays the role of isolating gas, so that gas can only enter the separator cylinder 120. An air intake channel 121 is provided between the separator cylinder 120 and the air intake pipe 112, and the gas input by the air intake pipe 112 can only enter the air intake channel 121.

[0021] As one implementation method in this embodiment, such as Figures 5 to 10As shown, a fiberglass pleated coarse filter layer 122 is fixedly installed on the inner wall of the separator 120. Multiple sets of the fiberglass pleated coarse filter layer 122 are evenly distributed on the periphery of the separator 120. The fiberglass pleated coarse filter layer 122 is 50μm thick and can trap large particles of impurities to protect the downstream precision filter element. Multiple sets of limiting strips 123 are evenly fixedly installed on the inner wall of the separator 120. A single spiral cooling pipe 124 is fixedly installed on the inner wall of each set of limiting strips 123, and both ends of the spiral cooling pipe 124 are sealed and penetrate the side wall of the separator 120. The spiral cooling pipe 124 is made of copper. A gas cylinder 126 is fixedly installed on the outer wall of the separator 120, and both ends of the spiral cooling pipe 124 are connected to the gas cylinder 126. The two ends are sealed and connected. The gas cylinder 126 has a built-in air pump that can discharge the gas in the gas cylinder 126 from the top into the spiral cooling tube 124, and then from the end of the spiral cooling tube 124 into the gas cylinder 126. The gas cylinder 126 is filled with low-temperature gas, which can condense the introduced gas to remove liquid impurities and oil vapors from the gas. The top of the spiral cooling tube 124 is provided with a guide groove 125, and the guide groove 125 connected to the bottom end of the spiral cooling tube 124 is twisted at 90°. The guide groove 125 can allow the liquid condensed by the spiral cooling tube 124 to flow through. At the same time, the guide groove 125 is twisted at the end of the spiral cooling tube 124 to guide the liquid into the receiving shell 113.

[0022] In this embodiment, as Figure 8 and Figure 9 As shown, a dust collector filter element 130 is fixedly installed on the inner wall of the separation cylinder 120. Multiple sets of dust collector filter elements 130 are arranged in a linear array within the separation cylinder 120. The dust collector filter element 130 uses a 5μm polytetrafluoroethylene precision dust collector filter element, capable of removing fine suspended dust from the gas. A breathable bag 131 is fixedly installed on the inner wall of the top of the separation cylinder 120. The breathable bag 131 is filled with solid neutralizing filter material 132. The solid neutralizing filter material 132 refers to the material used in the filtration neutralization method or solid... In chemical purification, a medium that uses solid particles to react chemically with fluids (wastewater or waste gas) to remove acidic / alkaline substances is used. In this invention, the solid neutralizing filter material 132 uses sodium bicarbonate and dolomite, which can react with corrosive media (hydrogen sulfide, sulfur dioxide) such as volatile organic acids in the gas, thereby removing acidic impurities from the gas. The bottom of the separation cylinder 120 is provided with a sewage outlet 127, and the sewage outlet 127 is connected to the inside of the receiving shell 113.

[0023] As one implementation method in this embodiment, such as Figures 11 to 13As shown, a top support shell 140 is sealed and fixed to the top port of the housing 110. A screw 141 is fixedly installed on the inner wall of the middle part of the top support shell 140. A connecting column 142 is fixedly installed on the inner wall of the middle part of the screw 141. A positioning nut 143 is engaged on the screw 141. By adjusting the position of the positioning nut 143 on the screw 141, the sliding column 144 can be limited, thereby regulating the air pressure in the pressure stabilizing shell 150. The larger the distance between the positioning nut 143 and the sliding column 144, the greater the pressure in the pressure stabilizing shell 150. The higher the maintained air pressure, the more important it is to seal and fix a pressure stabilizing shell 150 on the inner wall of the housing 110. The outer wall of the pressure stabilizing shell 150 has four sets of evenly spaced air inlets 151. The top opening of the separator 120 communicates with the air inlets 151, and the gas inside the separator 120 can only enter the pressure stabilizing shell 150 through the air inlets 151. A sliding column 144 is slidably installed on the top inner wall of the pressure stabilizing shell 150. An elastic sealing membrane 145 is fixedly installed on the outer wall of the middle part of the sliding column 144. 5. The outer wall is fixedly connected to the inner wall of the housing 110. The elastic sealing membrane 145 can limit the sliding column 144. The connecting column 142 slides through the top of the sliding column 144. A spring 146 is fixedly installed on the top of the sliding column 144, and the other end of the spring 146 is fixedly connected to the inner wall of the top support shell 140. The spring 146 increases the reverse elastic force, which can suppress the upward movement of the sliding column 144. A sealing ring 148 is sleeved on the outer wall of the sliding column 144, and the sealing ring 148 contacts the inner wall of the pressure stabilizing shell 150. The sliding column 144 is slidably connected to the pressure stabilizing shell 150 through the sealing ring 148. The pressure stabilizing shell 150 has an air outlet 153 at the bottom. A blocking rod 147 is fixedly installed at the bottom of the sliding column 144, and the blocking rod 147 works in conjunction with the air outlet 153. In the initial state, the blocking rod 147 blocks the air outlet 153. When the air pressure inside the pressure stabilizing shell 150 increases, the air pressure pushes the sliding column 144, which can drive the air outlet 153 to separate from the blocking rod 147, thereby achieving the purpose of stabilizing and outputting gas.

[0024] In this embodiment, as Figure 12 As shown, a hydrophobic and breathable membrane 152 is fixedly installed on the inner wall of the air inlet 151. The hydrophobic and breathable membrane 152 can remove residual saturated water vapor and trace amounts of condensation in the gas. A dehumidifying packing 154 is installed inside the pressure stabilizing shell 150, and the plug rod 147 slides through the dehumidifying packing 154. The dehumidifying packing 154 is a 3A hollow molecular sieve dehumidifying packing, the main component of which is 3A zeolite molecular sieve (potassium sodium aluminosilicate), with an effective pore size of about 3 Å. It is specifically used to selectively adsorb water molecules while repelling large molecular gases such as nitrogen and oxygen.

[0025] As one implementation method in this embodiment, such as Figure 5 and Figure 7As shown, a detection tube 114 is sealed and fixed to the end port of the housing 110, and a detection device is connected to the external of the detection tube 114. The detection device can detect the gas inside the detection tube 114. However, during the detection, the gas needs to impact the detection head with a stable air pressure. At the same time, it is also necessary to remove moisture and corrosive gases from the gas to prevent them from damaging the probe. The detection tube 114 is connected to the air outlet 153. A pressure gauge 115 is fixedly installed on the top of the end of the housing 110, and the pressure gauge 115 can detect the air pressure inside the detection tube 114. The pressure gauge 115 can display the air pressure on the probe during the detection.

[0026] As one implementation method in this embodiment, such as Figures 1 to 4 As shown, a mixing chamber 200 has a mixing channel 240 inside. A gas supply pipe 210 is fixedly installed at the end of the mixing channel 240, and the gas supply pipe 210 is sealed and connected to the inlet pipe 112. The gas supply pipe 210 can input the uniformly mixed gas into the inlet pipe 112. A single-pass pipe 220 is fixedly installed at the front end of the mixing channel 240. The single-pass pipe 220 is open on one side, and three sets of ventilation pipes 221 are evenly fixedly installed on the side wall of the single-pass pipe 220. A suction hose 222 is fixedly installed at the opening of the ventilation pipe 221, and the three sets of suction hoses 222 are respectively located in the upper, middle and lower parts of the gas to be tested. The suction hoses 222 can extract the gas from each layer in the confined space, preventing inaccurate test results due to gas deposition or floating. An anti-tangling filter 223 is fixedly installed on the inner wall of the front end of the suction hose 222. The anti-tangling filter 223 can intercept fibers, weeds and lint in the confined space. To prevent clogging of the suction hose 222, a pump 230 is fixedly installed on the inner wall of the front end of the mixing channel 240. The input end of the pump 230 is connected to the inside of the single-pass pipe 220, and the output end of the pump 230 is connected to the inside of the mixing channel 240. The pump 230 can extract gas from the confined space through the single-pass pipe 220, the ventilation pipe 221, and the suction hose 222, and simultaneously discharge the extracted gas into the mixing channel 240. Multiple sets of mixing blades 250 are evenly fixedly installed on the inner wall of the mixing channel 240. The mixing channel 240 and the mixing blades 250 can play a role in gas mixing. The gas flows in the mixing channel 240 and impacts the mixing blades 250, increasing the velocity gradient of the laminar flow or forming turbulence. During the laminar flow, the various substances in the mixing channel 240 are fully mixed by repeatedly going through the steps of "merging, splitting, reversing, and remerging".

[0027] The working principle of the technical solution provided by the present invention is as follows: The entire device is installed outside a confined space (such as a municipal sewage well, power cable well, or water supply and drainage closed pipe trench) using cable ties and adhesive. Three sets of suction hoses 222 are extended into the confined space, positioned at the upper, middle, and lower parts of the confined space, respectively. Then, the air pump 230 is driven to generate negative pressure in the single-pass pipe 220. The three sets of suction hoses 222 are used to draw in the gas in the confined space. The anti-tangling filter 223 can block fibrous weeds, flocculent sludge, large pieces of mud and sand in the confined space, preventing the suction hoses 222 from becoming blocked. At this time, the gas drawn in contains small particulate impurities, oil and gas, liquid impurities, acid and alkali corrosive substances, etc. After being mixed by the mixing blades 250 in the mixing channel 240, the various gaseous substances drawn in can be evenly mixed and then input into the pressure stabilizing filter assembly 100 through the air delivery pipe 210. When the gas is uniformly mixed and enters the housing 110 through the inlet pipe 112, it enters the inlet channel 121 under the separation of the sealing partition 111. At this time, the 50μm glass fiber pleated coarse filter layer 122 can filter out large particulate impurities in the gas. The filtered gas can pass through the glass fiber pleated coarse filter layer 122 and enter the separation cylinder 120. Since the low-temperature gas in the gas cylinder 126 flows in the spiral cooling tube 124, when the gas to be tested comes into contact with the spiral cooling tube 124, the oil and liquid impurities in the gas will condense into liquid on the spiral cooling tube 124 and flow in the guide groove 125 on the spiral cooling tube 124. Since the guide groove 125 is twisted at the end of the spiral cooling tube 124 (refer to the instruction manual appendix). Figure 10 As shown), at this time, the liquid in the guide channel 125 can flow into the receiving shell 113, and the condensate in the separation cylinder 120 can settle to the bottom of the receiving shell 113. After removing oil and liquid impurities, the gas passes through the 5μm polytetrafluoroethylene precision dust removal filter element 130 built into the separator 120, which can remove fine suspended dust in the gas. At the same time, the solid neutralizing filter material 132 (sodium bicarbonate, dolomite) in the breathable bag 131 can react with corrosive media (hydrogen sulfide, sulfur dioxide) such as volatile organic acids in the gas, thereby removing acidic impurities in the gas. After removing fine suspended dust and acidic impurities, the gas enters the pressure stabilizing shell 150 through the top opening of the separator 120 and the air inlet 151. At this time, the hydrophobic and breathable membrane 152 in the air inlet 151 can remove moisture (some water vapor is carried when condensation occurs on the spiral cooling pipe 124) and trace amounts of condensation from the gas. As gas is continuously introduced into the pressure stabilizing shell 150, its pressure continuously increases. At this time, the pressure can squeeze the sliding column 144 to move it upward, while the spring 146 is compressed, and the sliding column 144 drives the blocking rod 147 to move upward, so that the gas is discharged. When hole 153 is opened, the gas inside the pressure stabilizing housing 150 passes through the dehumidifying packing 154 and the outlet hole 153 and is stably discharged into the detection tube 114, where it is detected by the detector inside the detection tube 114. After the gas pressure inside the pressure stabilizing housing 150 reaches a constant value, the sliding column 144 contacts the positioning nut 143, making the outlet gas pressure of the outlet hole 153 constant. The dehumidifying packing 154 can absorb excess moisture in the gas and stably control the relative humidity of the outlet gas at 5%-8%, completely eliminating the damage of condensate to the detector circuit and probe.

[0028] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0029] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A gas detection pretreatment device for a confined space, comprising a pressure-stabilizing filter assembly (100) and a mixing chamber (200), wherein the mixing chamber (200) is installed at the front end of the pressure-stabilizing filter assembly (100), and the input port of the mixing chamber (200) is in communication with the interior of the gas to be tested, characterized in that, The pressure stabilizing and filtering assembly (100) includes a housing (110), an air inlet pipe (112) is sealed and fixedly connected to the front end of the housing (110), a receiving shell (113) is sealed and fixedly installed at the bottom end of the housing (110), a separation cylinder (120) is provided inside the receiving shell (113), a sealing partition (111) is sealed and fixedly connected to the top outer wall of the separation cylinder (120), and the sealing partition (111) is sealed and fixedly connected to the inner wall of the housing (110). An air inlet channel (121) is provided between the separation cylinder (120) and the air inlet pipe (112), and the gas input by the air inlet pipe (112) can only enter the air inlet channel (121).

2. The gas detection pretreatment device for a confined space according to claim 1, characterized in that, A fiberglass pleated coarse filter layer (122) is fixedly installed on the inner wall of the separation cylinder (120). The fiberglass pleated coarse filter layer (122) is provided in multiple sets and is evenly distributed on the periphery of the separation cylinder (120). Multiple sets of limiting strips (123) are evenly fixedly installed on the inner wall of the separation cylinder (120). The same spiral cooling pipe (124) is fixedly installed on the inner wall of the multiple sets of limiting strips (123). Both ends of the spiral cooling pipe (124) are sealed and penetrate the side wall of the separation cylinder (120). A gas cylinder (126) is fixedly installed on the outer wall of the separation cylinder (120). Both ends of the spiral cooling pipe (124) are sealed and connected to the two ports of the gas cylinder (126). A guide groove (125) is opened at the top of the spiral cooling pipe (124). The guide groove (125) connecting the spiral cooling pipe (124) and the bottom port of the gas cylinder (126) is twisted at 90°.

3. A gas detection pretreatment device for confined spaces according to claim 2, characterized in that, The inner wall of the separation cylinder (120) is fixedly installed with a dust removal filter element (130). The dust removal filter element (130) is provided in multiple sets and is distributed in a linear array inside the separation cylinder (120). The inner wall of the top of the separation cylinder (120) is fixedly installed with a breathable bag (131). The breathable bag (131) is filled with solid neutralizing filter material (132). The bottom of the separation cylinder (120) is provided with a sewage outlet (127), and the sewage outlet (127) is connected to the inside of the receiving shell (113).

4. A gas detection pretreatment device for a confined space according to claim 1, characterized in that, The top port of the housing (110) is sealed and fixedly connected to a top support shell (140). A screw (141) is fixedly installed on the inner wall of the middle part of the top support shell (140). A connecting column (142) is fixedly installed on the inner wall of the middle part of the screw (141). A positioning nut (143) is engaged on the screw (141). A pressure stabilizing shell (150) is sealed and fixedly installed on the inner wall of the housing (110). Four sets of air inlets (151) are evenly opened on the outer wall of the pressure stabilizing shell (150). The top opening of the separator (120) is connected to the air inlets (151), and the gas in the separator (120) can only enter the pressure stabilizing shell (150) through the air inlets (151).

5. A gas detection pretreatment device for a confined space according to claim 4, characterized in that, The pressure stabilizing shell (150) has a sliding column (144) installed on the inner wall of the top. An elastic sealing membrane (145) is fixedly installed on the outer wall of the middle part of the sliding column (144), and the outer wall of the elastic sealing membrane (145) is fixedly connected to the inner wall of the housing (110). The connecting column (142) slides through the top of the sliding column (144). A spring (146) is fixedly installed on the top of the sliding column (144), and the other end of the spring (146) is fixedly connected to the inner wall of the top support shell (140). A sealing ring (148) is sleeved on the outer wall of the sliding column (144), and the sealing ring (148) contacts the inner wall of the pressure stabilizing shell (150). An air outlet (153) is opened at the bottom of the pressure stabilizing shell (150). A plug rod (147) is fixedly installed at the bottom of the sliding column (144), and the plug rod (147) is used in conjunction with the air outlet (153).

6. A gas detection pretreatment device for a confined space according to claim 4, characterized in that, A hydrophobic and breathable membrane (152) is fixedly installed on the inner wall of the air inlet (151), and a dehumidifying packing (154) is installed inside the pressure stabilizing shell (150), and the plug rod (147) slides through the dehumidifying packing (154).

7. A gas detection pretreatment device for a confined space according to claim 5, characterized in that, The end port of the housing (110) is sealed and fixedly connected to a detection tube (114), and the detection tube (114) is connected to an external detection device. The detection tube (114) is connected to the air outlet (153). A pressure gauge (115) is fixedly installed on the top of the end of the housing (110), and the pressure gauge (115) can detect the air pressure inside the detection tube (114).

8. A gas detection pretreatment device for a confined space according to claim 1, characterized in that, The mixing chamber (200) has a mixing channel (240) inside. A gas supply pipe (210) is fixedly installed at the end of the mixing channel (240) and is sealed and connected to the air inlet pipe (112). A single-pass pipe (220) is fixedly installed at the front end of the mixing channel (240). Three sets of air vents (221) are evenly fixedly installed on the side wall of the single-pass pipe (220). A suction hose (222) is fixedly installed at the opening of the air vent (221), and the three sets of suction hoses are connected to the air inlet pipe (221). The hose (222) is located in the upper, middle and lower parts of the gas to be tested. An anti-winding filter (223) is fixedly installed on the inner wall of the front end of the suction hose (222). An air pump (230) is fixedly installed on the inner wall of the front end of the gas mixing channel (240). The input end of the air pump (230) is connected to the inside of the single-pass pipe (220), and the output end of the air pump (230) is connected to the inside of the gas mixing channel (240). Multiple sets of mixing blades (250) are evenly fixedly installed on the inner wall of the gas mixing channel (240).

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