Formaldehyde gas generation device by permeation gas distribution method and method thereof

Abstract

The present application relates to gas generating mechanical equipment technical field, and disclose a kind of permeation gas distribution method formaldehyde gas generating device and method thereof, including rack, the rack is equipped with permeation unit, constant temperature and humidity control unit, carrier gas distribution unit, detection control unit, gas path connection unit and safety protection unit, the permeation unit is located in the constant temperature and humidity control unit inside, the permeation unit end is connected with the carrier gas distribution unit, permeation unit innovation, permeation stability and adjustability significantly improve: using multi-channel composite permeation cell and ultrasonic homogenization module, solve the problem that existing device permeation source is not uniform, permeation rate fluctuation is big;Modified permeation membrane module uses hydrophobic TiO2 Nanoparticle modified PDMS / PVDF composite membrane, with good formaldehyde permeability and anti-polymerization pollution, extend the service life of membrane, different from the existing single permeation membrane design;Detachable structure design, convenient membrane module replacement and maintenance, improve versatility.

Description

Technical Field

[0001] This invention belongs to the technical field of gas generating machinery and equipment, specifically a formaldehyde gas generating device and method using the permeation gas mixing method. Background Technology

[0002] Formaldehyde, as one of the main indoor air pollutants, has a concentration that directly impacts environmental safety and human health. Precise and controllable formaldehyde standard gas is a core prerequisite for ensuring reliable test results. The permeation gas mixing method, with its advantages of high mixing accuracy, good gas stability, continuous and uninterrupted gas supply, and no secondary pollution, has become the mainstream technology for preparing low-concentration formaldehyde standard gas. Corresponding formaldehyde gas generators are widely used in scientific research, testing, metrological calibration, and other fields.

[0003] Currently, existing formaldehyde gas generation devices using the permeation gas mixing method have many inherent defects in their mechanical equipment structure design and performance, making it difficult to meet the requirements of high precision and wide application scenarios. Specific shortcomings are as follows: First, the permeation source structure design is unreasonable. Existing devices mostly use solid paraformaldehyde as the permeation source, achieving formaldehyde permeation through a single thermal decomposition method. This results in uneven thermal decomposition of the permeation source, easy agglomeration and aging, and large fluctuations in the permeation rate. The gas mixing accuracy generally fluctuates within ±5%, and frequent disassembly and replacement of the permeation source are required, making maintenance cumbersome and inefficient. Some devices using liquid formaldehyde as the permeation source lack effective homogenization structures, leading to easy precipitation and stratification of the formaldehyde solution, further exacerbating permeation instability. Second, the permeation membrane components lack targeted innovation. Existing devices mostly use single PDMS or PTFE membranes. These membrane materials easily adsorb formaldehyde polymerization products, resulting in a significant decrease in permeation efficiency after a period of use. Furthermore, they cannot balance formaldehyde permeability and anti-fouling properties, leading to short membrane component lifespans and increased operating costs. Simultaneously, the connection between the permeation membrane and the permeation tank is mostly fixed and sealed, making disassembly and replacement inconvenient and maintenance difficult. Third, the design of the constant temperature and humidity control system is rudimentary. Existing devices mostly use traditional water bath constant temperature or single-zone electric heating methods, resulting in slow temperature response, uneven temperature and humidity distribution within the cavity, and temperature deviations generally ≥ ±0.5℃. Even small fluctuations in temperature and humidity directly affect the formaldehyde permeation rate, leading to unstable gas concentration. Fourth, there are shortcomings in the gas path and gas distribution structure. Existing devices mostly have a single-path carrier gas distribution structure, which can only achieve gas distribution within a fixed concentration range and cannot meet the requirement of continuous adjustment over a wide concentration range (0.01mg / m³-100mg / m³). Furthermore, the gas path pipelines lack structures to prevent formaldehyde polymerization and residue, making it easy for formaldehyde gas to undergo polymerization reactions in the pipelines, affecting gas purity. At the same time, there is a lack of effective leak detection and emergency handling mechanisms, resulting in insufficient safety during use. Fifth, the control and regulation methods are outdated. Existing devices mostly adopt open control, which can only control the gas distribution process through preset parameters. They cannot detect the concentration of output formaldehyde gas in real time, nor can they perform closed-loop feedback regulation of parameters such as permeation rate and carrier gas flow rate based on concentration deviation, making it difficult to improve gas distribution accuracy. Moreover, most functional units are integrated fixed structures, which are difficult to disassemble, maintain and replace parts, resulting in poor versatility.

[0004] To address the inherent shortcomings of the existing technologies, there is an urgent need to design a formaldehyde gas generator using the permeation gas mixing method that features innovative structure, stable performance, precise gas mixing, convenient maintenance, high safety, and significant differences from existing technologies. Through innovative design of each unit of the mechanical equipment, the limitations of existing technologies can be overcome, meeting the needs for preparing high-precision formaldehyde standard gas in different scenarios. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the present invention provides a formaldehyde gas generating device and method by permeation gas mixing, which effectively solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a formaldehyde gas generating device using the permeation gas distribution method, comprising a frame, wherein the frame is provided with a permeation unit, a constant temperature and humidity control unit, a carrier gas distribution unit, a detection and control unit, a gas path connection unit, and a safety protection unit, wherein the permeation unit is located inside the constant temperature and humidity control unit, and the end of the permeation unit is connected to the carrier gas distribution unit; The permeation unit is used to generate formaldehyde vapor through permeation; the constant temperature and humidity control unit provides a suitable environment for generating formaldehyde vapor; the carrier gas distribution unit is used for gas distribution and dilution to facilitate the generation of a suitable concentration of formaldehyde gas; the detection and control unit is used to detect and control the operation of the entire device; the gas path connection unit is used to connect the corresponding unit components; and the safety protection unit is used to provide safety protection for the entire device and improve the safety of its use.

[0007] Preferably, the permeation unit includes a permeation chamber containing several permeation chambers. A fixed pipe is connected to the top outlet of each permeation chamber, and a connector is connected to the fixed pipe. A modified permeation membrane is installed inside the connector and is located at the top of the permeation chamber. A liquid check valve is connected to the lower inlet of each permeation chamber and is connected to the top of a liquid output pipe. The liquid output pipe is connected to an ultrasonic vibrator mounted on a frame. One end of a delivery pipe is connected to the ultrasonic vibrator, and the other end of the delivery pipe is connected to a precision liquid metering pump. The precision liquid metering pump is connected to the lower part of a liquid supply valve, which is installed at the bottom of a formaldehyde liquid storage tank. A liquid temperature sensor for measuring the temperature of the formaldehyde liquid inside the tank is installed on the formaldehyde liquid storage tank, as is a liquid level sensor for measuring the formaldehyde liquid level. An injection valve is located at the top of the formaldehyde liquid storage tank, and the permeation chamber is equipped with a permeation ultrasonic vibrator. A rectangular channel is machined through the middle of the infiltration chamber, and the infiltration ultrasonic vibrator is installed at the bottom of the rectangular channel. The permeation chambers are arranged in an array within the permeation chamber, forming a rectangular shape; The ultrasonic vibrator has several connection channels. The infusion tube and the liquid output tube are connected through the connection channels, and the infusion tube and the modified permeation membrane are connected in a one-to-one correspondence. The formaldehyde liquid storage tank is supported at the bottom by a bottom support ring, which is mounted on a mounting plate. The mounting plate is connected to the side wall of the frame. An upper cover ring is pressed onto the upper side of the formaldehyde liquid storage tank. The upper cover ring is connected to a nut plate, which is detachably connected to the mounting plate. The inner surfaces of the bottom support ring and the upper cover ring are provided with anti-slip material.

[0008] Preferably, the inner side of the connector has an annular protrusion to press the modified permeable membrane, so that the modified permeable membrane is pressed between the annular protrusion and the fixed tube, and a certain amount of venting space is reserved on the upper side of the annular protrusion. The modified permeation membrane is a PDMS / PVDF composite membrane modified with hydrophobic TiO2 nanoparticles. PVDF serves as the base membrane to ensure the membrane's mechanical strength and permeability, while PDMS serves as the intermediate layer to enhance formaldehyde permeability. The hydrophobic TiO2 nanoparticles serve as the surface modifier, effectively inhibiting the adsorption and polymerization of formaldehyde molecules on the membrane surface, reducing membrane fouling, extending the service life of the modified permeation membrane, and improving the stability of formaldehyde permeation.

[0009] Preferably, the constant temperature and humidity control unit includes a constant temperature and humidity chamber, which is mounted on the upper side of the frame via constant temperature and humidity chamber support legs. A rectangular frame is connected to the constant temperature and humidity chamber, and the permeation chamber is connected to the rectangular frame. The lower part of the permeation chamber is flush with the bottom of the constant temperature and humidity chamber. A constant temperature component is connected to the constant temperature and humidity chamber. The constant temperature component includes electric heating wires evenly installed on the inner surface of the constant temperature and humidity chamber. Semiconductor cooling is installed on the inner surface of the constant temperature and humidity chamber between the electric heating wires. The constant temperature and humidity chamber has several exhaust channels processed through it. A micro fan is installed in each exhaust channel, and a gas flow valve is connected to the outlet of the exhaust channel. The constant temperature and humidity chamber is connected to a humidity control component, which includes a water-absorbing cotton insert plate inserted into the chamber. The inner surface of the water-absorbing cotton insert plate is connected to water-absorbing cotton. Several atomizing channels are machined through the rectangular frame. An atomizing nozzle is connected to the lower outlet of each atomizing channel. One end of an atomizing gas tube is connected to the upper inlet of each atomizing channel. The other end of the atomizing gas tube is connected to the outlet of an atomizing tee tube. The inlet of the atomizing tee tube is connected to an atomizer. The atomizer is connected to the frame. An atomizing one-way valve is connected in series between the outlet of the atomizing tee tube and the atomizing gas tube. The constant temperature and humidity chamber is equipped with a humidity sensor and a temperature sensor for monitoring the humidity and temperature inside the chamber. The exhaust channels are all located on the side walls of the constant temperature and humidity chamber, and there are several on each side wall; The inner surface of the constant temperature and humidity chamber is provided with heat insulation material.

[0010] Preferably, the carrier gas distribution unit includes a carrier gas tank mounted on the frame. An air supply valve is connected to the upper outlet of the carrier gas tank. One end of an air supply pipe is connected to the air supply valve. The other end of the air supply pipe is connected to the filter inlet. A connecting pipe connects the filter outlet and the dryer inlet. One end of an output pipe is connected to the dryer outlet. The other end of the output pipe is connected to a carrier gas tee. The two outlets of the carrier gas tee are respectively connected to a dilution gas path precision flow controller and a bottom gas path precision flow controller. One end of a bottom gas path branch pipe is connected to the bottom gas path precision flow controller. The other end of the bottom gas path branch pipe is connected to a bottom gas check valve. The bottom gas check valve is installed in the mixing unit. An adjustable throttle valve is connected in series with one inlet of the connecting pipe to the bottom gas path branch pipe. One end of the permeation branch pipe is connected to the connector plug. The other end of the permeation branch pipe is connected to the manifold pipe. A shut-off valve is connected in series with the permeation branch pipe. The other end of the manifold pipe is connected to the gas collection check valve. The gas collection check valve is installed on the other inlet of the mixing tee pipe. A permeation gas flow sensor is connected to the manifold pipe. The outlet of the mixing tee pipe is connected to the lower part of the gas buffer cylinder. A mixing box is connected to the upper part of the gas buffer cylinder. A spiral mixing blade is installed inside the mixing box. A gas buffer cylinder is connected between the mixing box and the dilution gas path precision flow controller. A dilution check valve is connected in series with the gas buffer cylinder. The spiral mixing blades are provided in two layers, and are nested in the inner and outer layers. The spiral mixing blades are located on the upper side of the gas buffer cylinder outlet. The dryer and the filter are installed in a mounting box, which is mounted on the frame. The gas buffer cylinder and the inner wall of the mixing chamber are coated with a fluorocarbon anti-polymerization coating. A safety valve is installed on the carrier gas tank, and a carrier gas temperature sensor is installed on the carrier gas tank. The mixing chamber is mounted on the frame via a mixing chamber base.

[0011] Preferably, a formaldehyde gas collection unit is connected to the top of the mixing chamber. The formaldehyde gas collection unit includes a collection check valve connected to the outlet of the top of the mixing chamber. A collection pipe is connected between the collection check valve and the collection pressure gauge. The collection pressure gauge is installed on the upper part of the collection valve. The collection valve is installed on the upper part of the collection tank. The collection tank is installed on the frame. A formaldehyde concentration sensor is connected to the collection pipe.

[0012] Preferably, the detection and control unit includes a control console mounted on the frame, the control console is equipped with a PLC controller, the PLC controller is connected to the electrical components in the device via signals, and the detection unit also includes a data acquisition module and an execution module; The data acquisition module is used to collect relevant operating parameters, organize and store the data, and display it in real time through the display screen of the operation panel. It also supports data export for easy analysis and calibration later. The execution module is used to receive control commands from the PLC controller and adjust the corresponding operating parameters.

[0013] The detection and control unit also includes a remote control module that supports wireless remote connection. Staff can use mobile phones, computers and other terminals to view the device's operating status and adjust operating parameters in real time, thereby achieving remote control and improving the ease of use of the device. It also features a parameter memory function, which can store multiple sets of commonly used gas mixing parameters, allowing for direct recall the parameters the next time they are used without the need for repeated settings.

[0014] Preferably, the gas connection unit includes a pipe connecting the permeation unit and the carrier gas distribution unit, and also includes pipes in the carrier gas distribution unit and the formaldehyde gas collection unit. The pipes are coated with an anti-polymerization coating to inhibit the adsorption and polymerization of formaldehyde molecules on the inner wall of the pipes.

[0015] Preferably, the safety protection unit includes a leakage detection module, an emergency handling module, and an overload protection module; The leakage detection module includes a formaldehyde leakage sensor and an audible and visual alarm device. The formaldehyde leakage sensor is evenly installed on the rack, at the gas connection point, and near the control console to detect whether formaldehyde leakage has occurred. The audible and visual alarm device is located at the corresponding position on the rack. The emergency response module includes an activated carbon adsorption box and an emergency exhaust fan. The activated carbon adsorption box is located inside the frame and is used to adsorb leaked formaldehyde gas to avoid environmental pollution and harm to human health. The emergency exhaust fan is installed at a corresponding position on the frame. The overload protection module is used to protect the circuit, motor, heating wire and other components of the device from overload. When the components are overloaded or short-circuited, the power supply is automatically cut off to prevent damage to the components and extend the service life of the device.

[0016] This invention provides a method for using a formaldehyde gas generator using the permeation gas mixing method. Based on the aforementioned formaldehyde gas generator using the permeation gas mixing method, the steps include: Step 1: Preliminary preparation: Inject formaldehyde solution into the formaldehyde liquid storage tank, check the connection status of each unit, ensure that the gas path is well sealed and the circuit connection is normal, set the preset parameters through the operation panel, start the device, and initialize each unit of the PLC controller. Step 2: Temperature and humidity control adjustment: The temperature and humidity control unit is activated to stabilize the temperature and humidity of the temperature and humidity chamber at the preset values; Step 3: Formaldehyde Permeation: The permeation unit is activated to permeate the formaldehyde solution and generate formaldehyde vapor; Step 4: Carrier gas distribution and mixing: The carrier gas distribution unit is activated to mix and dilute the generated formaldehyde vapor; Step 5: Formaldehyde gas collection: The formaldehyde gas collection unit moves to collect the generated formaldehyde gas; Step Six: Throughout the entire operation of the device, the detection and control unit and the safety protection unit remain in operation to detect and control the entire device's operation and provide safety protection.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention provides a formaldehyde gas generating device using a permeation gas distribution method. The permeation unit is innovative, significantly improving permeation stability and adjustability: it adopts a multi-channel composite permeation tank and an ultrasonic homogenization module to solve the problems of uneven permeation source and large fluctuations in permeation rate in existing devices; the modified permeation membrane module uses a hydrophobic TiO2 nanoparticle modified PDMS / PVDF composite membrane, which has both good formaldehyde permeability and resistance to polymerization fouling, extending the membrane's service life, unlike existing single permeation membrane designs; the detachable structural design facilitates membrane module replacement and maintenance, improving versatility.

[0018] 2. This invention provides a formaldehyde gas generator using a permeation gas distribution method. The optimized constant temperature and humidity control structure significantly improves environmental stability: It employs a surround-type bidirectional temperature control chamber and a micro-circulating fan assembly to achieve precise bidirectional temperature and humidity control, ensuring a stable formaldehyde permeation rate; a combined humidity adjustment module can accurately match different permeation requirements, further improving gas distribution accuracy; and an innovative carrier gas distribution structure enables wide-concentration continuous adjustment: dual-channel precision flow controllers coordinate gas distribution, combined with a carrier gas pretreatment module and a high-efficiency mixing chamber, overcoming the limitations of existing devices with a single carrier gas channel. The carrier gas pretreatment design effectively improves the purity of the formaldehyde gas. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the first orientation of a formaldehyde gas generating device using the permeation gas mixing method according to the present invention; Figure 2 This is a schematic diagram of the second orientation of a formaldehyde gas generating device using the permeation gas distribution method according to the present invention; Figure 3This is a third-direction structural schematic diagram of a formaldehyde gas generating device using the permeation gas mixing method according to the present invention; Figure 4 This is a schematic diagram of the fourth direction structure of a formaldehyde gas generating device using the permeation gas mixing method in this invention; Figure 5 This is a schematic diagram of the fifth direction of a formaldehyde gas generating device using the permeation gas mixing method according to the present invention. Figure 6 This is a first disassembled structural diagram of a formaldehyde gas generating device using the permeation gas mixing method according to the present invention; Figure 7 This is a schematic diagram of the second disassembled structure of a formaldehyde gas generating device using the permeation gas distribution method according to the present invention; Figure 8 This is a first partial cross-sectional view of a formaldehyde gas generating device using the permeation gas mixing method according to the present invention; Figure 9 This is a second partial cross-sectional view of a formaldehyde gas generating device using the permeation gas distribution method according to the present invention; Figure 10 This is a schematic diagram of the structure of the combination of the permeation unit and the constant temperature and humidity control unit in this invention; Figure 11 This is a schematic diagram of the first direction structure of the permeation unit in this invention: Figure 12 This is a schematic diagram of the second direction structure of the permeation unit in this invention; Figure 13 This is a schematic diagram of the third-direction structure of the permeation unit in this invention.

[0021] In the diagram: 1-Frame, 2-Carrier gas tank, 3-Safety valve, 4-Gas supply valve, 5-Gas supply pipe, 6-Mounting box, 7-Output pipe, 8-Collection tank, 9-Collection valve, 10-Collection pressure gauge, 11-Collection pipe, 12-Formaldehyde concentration sensor, 13-Mixing box, 14-Combination pipe, 15-Permeation branch pipe, 16-Injection valve, 17-Liquid temperature sensor, 18-Nut plate, 19-Bolt, 20-Mounting plate, 21-Upper cover ring, 22-Formaldehyde liquid 23-Bottom support ring, 24-Constant temperature and humidity chamber, 25-Infusion tube, 26-Absorbent cotton insert, 27-Ultrasonic vibrator, 28-Mixing tank base, 29-Control console, 30-Level sensor, 31-Stop valve, 32-Gas flow valve, 33-Atomizing gas tube, 34-Collection check valve, 35-Connecting plug, 36-Precision flow controller for dilution gas path, 37-Carrier gas tee, 38-Precision flow controller for bottom gas path, 39-Bottom gas path Branch pipe, 40-Adjustable throttle valve, 41-Permeate gas flow sensor, 42-Atomizing check valve, 43-Atomizing tee, 44-Atomizer, 45-Liquid supply valve, 46-Liquid precision metering pump, 47-Mixing tee, 48-Gas manifold check valve, 49-Bottom gas check valve, 50-Spiral mixing blade, 51-Dilution check valve, 52-Dryer, 53-Filter, 54-Connecting pipe, 55-Rectangular frame, 56-Permeate chamber, 57-Exhaust channel 58-Miniature fan, 59-Modified permeation membrane, 60-Permeation chamber, 61-Humidity sensor, 62-Liquid check valve, 63-Temperature sensor, 64-Electric heating wire, 65-Semiconductor refrigeration, 66-Absorbent cotton, 67-Atomizing nozzle, 68-Atomizing channel, 69-Liquid output pipe, 70-Permeation ultrasonic vibrator, 71-Constant temperature and humidity chamber support leg, 72-Gas buffer cylinder, 73-Dilution pipeline, 74-Carrier gas temperature sensor, 75-Fixing pipe. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1-13 As shown, the present invention provides a formaldehyde gas generating device using the permeation gas distribution method, including a frame 1. The frame 1 is provided with a permeation unit, a constant temperature and humidity control unit, a carrier gas distribution unit, a detection and control unit, a gas path connection unit, and a safety protection unit. The permeation unit is located inside the constant temperature and humidity control unit, and the end of the permeation unit is connected to the carrier gas distribution unit. The permeation unit is used to generate formaldehyde vapor through permeation; the constant temperature and humidity control unit provides a suitable environment for generating formaldehyde vapor; the carrier gas distribution unit is used for gas distribution and dilution to facilitate the generation of a suitable concentration of formaldehyde gas; the detection and control unit is used to detect and control the operation of the entire device; the gas path connection unit is used to connect the corresponding unit components; and the safety protection unit is used to provide safety protection for the entire device and improve the safety of the device. The connections between components in the entire device are well sealed.

[0024] Advantageously, the permeation unit includes a permeation chamber 56, which contains a plurality of permeation chambers 60. A fixed pipe 75 is connected to the top outlet of each permeation chamber 60, and a connecting plug 35 is connected to the fixed pipe 75. A modified permeation membrane 59 is installed inside the connecting plug 35 and is located at the top of each permeation chamber 60. A liquid one-way valve 62 is connected to the lower inlet of each permeation chamber 60. The liquid one-way valve 62 restricts the unidirectional flow of liquid, ensuring that liquid can only enter the permeation chamber 60. The liquid one-way valve 62 is connected to the top of a liquid output pipe 69, which is connected to an ultrasonic vibrator 27. The ultrasonic vibrator 27 is mounted on the frame 1. One end of the infusion tube 25 is connected to the other end of the infusion tube 25, which is connected to a precision liquid metering pump 46. The precision liquid metering pump 46 can extract liquid and monitor and adjust the flow rate. The precision liquid metering pump 46 is connected to the lower part of the liquid supply valve 45, which is installed at the lower part of the formaldehyde liquid storage tank 22. The formaldehyde liquid storage tank 22 is equipped with a liquid temperature sensor 17 for measuring the temperature of the formaldehyde liquid inside the tank, and a liquid level sensor 30 for measuring the liquid level of the formaldehyde liquid inside the tank. The formaldehyde liquid storage tank 22 is equipped with an injection valve 16 at the top, and the permeation tank 56 is equipped with a permeation ultrasonic vibrator 70. A rectangular channel is machined through the middle of the infiltration box 56, and the infiltration ultrasonic vibrator 70 is installed at the bottom of the rectangular channel. The permeation chambers 60 are arranged in an array within the permeation box 56, forming a rectangular shape; The ultrasonic vibrator 27 has several connection channels. The infusion tube 25 and the liquid output tube 69 are connected through the connection channels, and the infusion tube 25 and the modified permeation membrane 59 are connected one-to-one. The formaldehyde liquid storage tank 22 is supported and installed at the bottom by a bottom support ring 23, which is mounted on a mounting plate 20. The mounting plate 20 is connected to the side wall of the frame 1. An upper cover ring 21 is pressed against the upper side of the formaldehyde liquid storage tank 22. The upper cover ring 21 is connected to a nut plate 18, which is detachably connected to the mounting plate 20. The inner surfaces of the bottom support ring 23 and the upper cover ring 21 are provided with anti-slip material. The upper cover ring 21 and the bottom support ring 23 cooperate with each other to achieve positioning and support installation of the formaldehyde liquid storage tank 22. During operation, formaldehyde solution is added to the formaldehyde liquid storage tank 22 through the injection valve 16. After injection, the injection valve 16 is closed, the liquid supply valve 45 is opened, and the liquid precision metering pump 46 is started to extract the formaldehyde solution from the formaldehyde liquid storage tank 22. The formaldehyde solution flows through the liquid supply valve 45, through the liquid precision metering pump 46, and into the delivery pipe 25, then into the connecting channel of the ultrasonic vibrator 27. The ultrasonic vibrator 27 is turned on to perform ultrasonic vibration on the formaldehyde solution passing through it. After vibration, the solution flows through the liquid output pipe 69, through the liquid one-way valve 62, and into the permeation chamber 60. The permeation ultrasonic vibrator 70 is turned on, causing the permeation tank 56 to vibrate, thereby causing the formaldehyde solution in the permeation chamber 60 to vibrate. Vibration eliminates concentration stratification, prevents paraformaldehyde sedimentation, and avoids excessively high local concentrations. To ensure that the concentration of the liquid phase remains uniform, and after constant temperature and humidity treatment, the free surface of the formaldehyde solution comes into contact with the air space below the modified permeation membrane 59, forming a stable liquid-gas interface. Under constant temperature and humidity conditions, formaldehyde molecules diffuse from the liquid phase to the liquid surface, overcome the surface tension of the liquid, and enter the gas phase to form formaldehyde saturated vapor. After being filtered by the modified permeation membrane 59, the formaldehyde vapor passes through the modified permeation membrane 59 and enters the upper side of the modified permeation membrane 59, thereby realizing the generation of formaldehyde vapor through permeation. The liquid level sensor 30 measures the liquid level in the formaldehyde liquid storage tank 22, and the liquid temperature sensor 17 measures the temperature of the liquid in the formaldehyde liquid storage tank 22 and transmits the signal to the PLC controller. When the preset alarm value is exceeded, the buzzer sounds an alarm, which facilitates timely replenishment of liquid and cooling. The PLC controller collects the signal transmitted by the liquid precision metering pump 46, which facilitates timely transmission of signals to adjust the flow rate of the liquid precision metering pump 46.

[0025] Advantageously, the inner side of the connector 35 is provided with an annular protrusion to press the modified permeation membrane 59, so that the modified permeation membrane 59 is pressed between the annular protrusion and the fixed tube 75, and a certain amount of exhaust space is reserved on the upper side of the annular protrusion. The modified permeation membrane 59 is a PDMS / PVDF composite membrane modified with hydrophobic TiO2 nanoparticles, prepared by a high-temperature crosslinking process. The membrane thickness is 50-100 μm, and the pore size is 0.1-0.5 μm. PVDF serves as the base membrane, ensuring its mechanical strength and permeability. PDMS serves as the intermediate layer, enhancing formaldehyde permeability. The hydrophobic TiO2 nanoparticles act as a surface modifier, effectively inhibiting the adsorption and polymerization of formaldehyde molecules on the membrane surface, reducing membrane fouling, extending the service life of the modified permeation membrane 59, and improving the stability of formaldehyde permeation. During operation, after formaldehyde vapor is generated, driven by the vapor pressure difference across the modified permeation membrane 59, formaldehyde vapor molecules are adsorbed on the lower surface of the modified permeation membrane 59, dissolved and diffused inside the modified permeation membrane 59, desorbed from the upper surface of the modified permeation membrane 59, and enter the gas phase channel above the modified permeation membrane 59 to form continuous, trace, stable, and measurable formaldehyde permeation vapor.

[0026] Advantageously, the constant temperature and humidity control unit includes a constant temperature and humidity chamber 24, which is mounted on the upper side of the frame 1 via constant temperature and humidity chamber support legs 71. A rectangular frame 55 is connected to the constant temperature and humidity chamber 24, and an infiltration chamber 56 is connected to the rectangular frame 55. The lower part of the infiltration chamber 56 is flush with the bottom of the constant temperature and humidity chamber 24. A constant temperature component is connected to the constant temperature and humidity chamber 24. The constant temperature component includes electric heating wires 64 evenly installed on the inner surface of the constant temperature and humidity chamber 24. Semiconductor cooling 65 is installed on the inner surface of the constant temperature and humidity chamber 24 between the electric heating wires 64. The constant temperature and humidity chamber 24 has several exhaust channels 57 through which it is processed. A micro fan 58 is installed in the exhaust channel 57, and a gas flow valve 32 is connected to the outlet of the exhaust channel 57. A humidity control component is connected to the constant temperature and humidity chamber 24. The humidity control component includes a water-absorbing cotton insert plate 26 inserted into the constant temperature and humidity chamber 24. Water-absorbing cotton 66 is connected to the inner surface of the water-absorbing cotton insert plate 26. Several atomizing channels 68 are processed through the rectangular frame 55. An atomizing nozzle 67 is connected to the lower outlet of the atomizing channel 68. One end of an atomizing gas pipe 33 is connected to the upper inlet of the atomizing channel 68. The other end of the atomizing gas pipe 33 is connected to the outlet of an atomizing three-way pipe 43. The inlet of the atomizing three-way pipe 43 is connected to an atomizer 44. The atomizer 44 is connected to the frame 1. An atomizing one-way valve 42 is connected in series between the outlet of the atomizing three-way pipe 43 and the atomizing gas pipe 33. The constant temperature and humidity chamber 24 is equipped with a humidity sensor 61 and a temperature sensor 63 for monitoring the humidity and temperature inside the chamber. The exhaust channels 57 are all located on the side walls of the constant temperature and humidity chamber 24, and several are provided on each side wall; The inner surface of the constant temperature and humidity chamber 24 is provided with heat insulation material; During operation, the PLC controller controls the electric heating wire 64 and the semiconductor refrigeration 65. Through the coordinated operation of the electric heating wire 64 and the semiconductor refrigeration 65, the temperature of the constant temperature and humidity chamber 24 can be precisely controlled bidirectionally to meet the needs of different permeation rates. The PLC controls the atomizer 44 and the atomizing one-way valve 42. When the atomizer 44 is activated, the water is atomized and flows through the atomizing three-way pipe 43, through the atomizing one-way valve 42, and into the atomizing channel 68. It is then sprayed out through the atomizing nozzle 67 into the constant temperature and humidity chamber 24, thereby controlling the humidity of the constant temperature and humidity chamber 24. The atomizing one-way valve 42 controls the flow rate of the water mist entering the atomizer 44. The micro fan 58 is activated, and its movement blows air to diffuse the water mist and circulate it within the constant temperature and humidity chamber 24. The gas flow valve 32 is opened, and its opening degree is adjusted to promote air circulation within the chamber, ensuring uniform temperature and humidity distribution. The humidity sensor 61 and temperature sensor 63 monitor the temperature and humidity within the chamber and transmit signals to the PLC controller. The PLC controller processes the signals and controls the movement of corresponding components to regulate the temperature and humidity. The absorbent cotton 66 absorbs excess moisture within the chamber.

[0027] Advantageously, the carrier gas distribution unit includes a carrier gas tank 2 mounted on the frame 1. The carrier gas tank 2 is used to store inert carrier gas. An air supply valve 4 is connected to the upper outlet of the carrier gas tank 2. One end of an air supply pipe 5 is connected to the air supply valve 4. The other end of the air supply pipe 5 is connected to the inlet of a filter 53. A connecting pipe 54 is connected between the outlet of the filter 53 and the inlet of a dryer 52. One end of an output pipe 7 is connected to the outlet of the dryer 52. The other end of the output pipe 7 is connected to a carrier gas tee pipe 37. The two outlets of the carrier gas tee pipe 37 are respectively connected to a dilution gas path precision flow controller 36 and a bottom gas path precision flow controller 38. One end of a bottom gas path branch pipe 39 is connected to the bottom gas path precision flow controller 38. The other end of the bottom gas path branch pipe 39 is connected to a bottom gas one-way valve 49. The bottom gas one-way valve 49 is installed in the mixing... An adjustable throttle valve 40 is connected in series with one inlet of the three-way pipe 47 and the bottom gas path branch pipe 39. One end of the permeation branch pipe 15 is connected to the connector 35. The other end of the permeation branch pipe 15 is connected to the manifold pipe 14. A shut-off valve 31 is connected in series with the permeation branch pipe 15. The other end of the manifold pipe 14 is connected to the gas collection check valve 48. The gas collection check valve 48 is installed on the other inlet of the mixing three-way pipe 47. A permeation gas flow sensor 41 is connected to the manifold pipe 14. The outlet of the mixing three-way pipe 47 is connected to the lower part of the gas buffer cylinder 72. A mixing box 13 is connected to the upper part of the gas buffer cylinder 72. A spiral mixing blade 50 is installed inside the mixing box 13. The gas buffer cylinder 72 is connected between the mixing box 13 and the dilution gas path precision flow controller 36. A dilution check valve 51 is connected in series with the gas buffer cylinder 72. Two spiral mixing blades 50 are provided, and the inner and outer layers are nested. The spiral mixing blades 50 are located on the upper side of the outlet of the gas buffer cylinder 72. The dryer 52 and the filter 53 are installed in the mounting box 6, and the mounting box 6 is installed on the frame 1; The gas buffer cylinder 72 and the inner wall of the mixing box 13 are coated with a fluorocarbon anti-polymerization coating. A safety valve 3 is installed on the carrier gas tank 2, and a carrier gas temperature sensor 74 is installed on the carrier gas tank 2; The mixing chamber 13 is mounted on the frame 1 via the mixing chamber base 28; During operation, the gas supply valve 4 is opened, and the inert carrier gas in the carrier gas tank 2 enters the gas supply pipe 5 through the gas supply valve 4. After being filtered by the filter 53 to remove impurities, the filtered gas then enters the dryer 52 through the connecting pipe 54 to remove moisture, preventing moisture and impurities from affecting the purity and permeation process of formaldehyde gas. The carrier gas then enters the carrier gas tee 37, where it is split. A portion of the gas passes through the bottom gas path precision flow controller 38. The formaldehyde vapor enters the bottom gas branch pipe 39, flows through the adjustable throttle valve 40, passes through the bottom gas check valve 49, and enters the mixing three-way pipe 47. When the shut-off valve 31 is opened, the formaldehyde vapor from the connector 35 flows through the shut-off valve 31 into the permeation branch pipe 15, then through the permeation branch pipe 15 into the manifold pipe 14, where it converges and flows. It then passes through the gas convergence check valve 48 and enters the mixing three-way pipe 47. The carrier gas and formaldehyde vapor are mixed in the mixing three-way pipe 47 and then enter the gas buffer cylinder 72. The formaldehyde vapor is initially mixed and diluted in the gas buffer cylinder 72 before entering the mixing box 13. The spiral mixing blades 50 guide the airflow, which will rotate and flow along the spiral trajectory. Another part of the carrier gas flows through the dilution gas path precision flow controller 36, through the dilution one-way valve 51, and through the dilution pipe 73 into the mixing box 13, where they meet. During this process, the spiral mixing blades 50 will cut, split, and mix the two airflows. The high-concentration formaldehyde airflow carried by the airflow entering from the lower part of the mixing box 13 is cut into small airflow bundles, which are fully intertwined with the diluted carrier gas airflow entering from the dilution pipe 73. At the same time, the spiral structure will force the airflow to continuously change its flow direction and speed, forming a composite movement of radial and axial directions, breaking the laminar flow state of the airflow, allowing formaldehyde molecules and diluted carrier gas molecules to diffuse quickly and come into full contact, thereby achieving uniform mixing. The permeate flow sensor 41 is used to collect the total flow rate of formaldehyde vapor in real time and transmit the flow data to provide data support for closed-loop control of the permeation rate. The total flow rate can be adjusted by closing and opening the corresponding shut-off valve 31. The gas collection check valve 48, the bottom gas check valve 49, and the dilution check valve 51 restrict the reverse flow of gas. The dilution gas path precision flow controller 36 and the bottom gas path precision flow controller 38 control and adjust the gas flow rate. The adjustable throttle valve 40 achieves throttling and better regulates the airflow in the bottom gas path branch pipe 39. The carrier gas temperature sensor 74 measures the temperature in the carrier gas tank 2. The safety valve 3 protects the inside of the carrier gas tank 2. When the pressure in the carrier gas tank 2 exceeds a certain value, it automatically releases pressure.

[0028] Advantageously, a formaldehyde gas collection unit is connected to the top of the mixing box 13. The formaldehyde gas collection unit includes a collection check valve 34 connected to the top outlet of the mixing box 13. A collection pipe 11 is connected between the collection check valve 34 and the collection pressure gauge 10. The collection pressure gauge 10 is installed on the upper part of the collection valve 9. The collection valve 9 is installed on the upper part of the collection tank 8. The collection tank 8 is installed on the frame 1. A formaldehyde concentration sensor 12 is connected to the collection pipe 11. During operation, diluted formaldehyde gas enters the collection pipe 11 through the collection check valve 34, flows through the collection pressure gauge 10 and the collection valve 9, and enters the collection tank 8. The formaldehyde concentration sensor 12 monitors the formaldehyde concentration of the formaldehyde gas flowing through the collection pipe 11 and transmits a signal to the PLC controller. After processing, the PLC controller controls the corresponding components to move, thereby adjusting the concentration of formaldehyde gas. The collection pressure gauge 10 measures the pressure in the collection tank 8. When the pressure reaches a certain value, the collection valve 9 closes, thus collecting the formaldehyde gas.

[0029] Advantageously, the detection and control unit includes a control console 29 mounted on the frame 1, the control console 29 is equipped with a PLC controller, the PLC controller is connected to the electrical components in the device, and the detection unit also includes a data acquisition module and an execution module; The data acquisition module is used to collect relevant operating parameters, organize and store the data, and display it in real time through the display screen of the operation panel. It also supports data export for easy analysis and calibration later. The execution module is used to receive control commands from the PLC controller and adjust the corresponding operating parameters.

[0030] The detection and control unit also includes a remote control module that supports wireless remote connection. Staff can use mobile phones, computers and other terminals to view the device's operating status and adjust operating parameters in real time, thereby achieving remote control and improving the ease of use of the device. It also features a parameter memory function, which can store multiple sets of commonly used gas mixing parameters, allowing for direct recall the parameters the next time they are used without the need for repeated settings.

[0031] During operation, the PLC controller processes the received data, sends signals to cause corresponding components to move, and adjusts the movement of these components to achieve the desired control and regulation. Advantageously, the gas connection unit includes a pipe connecting the permeation unit and the carrier gas distribution unit, and also includes pipes in the carrier gas distribution unit and the formaldehyde gas collection unit. The pipes are coated with an anti-polymerization coating to inhibit the adsorption and polymerization of formaldehyde molecules on the inner wall of the pipes.

[0032] Advantageously, the safety protection unit includes a leakage detection module, an emergency handling module, and an overload protection module; The leakage detection module includes a formaldehyde leakage sensor and an audible and visual alarm device. The formaldehyde leakage sensor is evenly installed on the rack 1, at the gas connection point, and near the control console 29 to detect whether formaldehyde leakage has occurred. The audible and visual alarm device is located at the corresponding position on the rack 1. The emergency treatment module includes an activated carbon adsorption box and an emergency exhaust fan. The activated carbon adsorption box is installed on the frame 1 and is used to adsorb leaked formaldehyde gas to avoid environmental pollution and harm to human health. The emergency exhaust fan is installed at a corresponding position on the frame 1. When a leak occurs, the emergency exhaust fan will automatically start to discharge the leaked gas to a designated recovery device to achieve emergency treatment. The overload protection module is used to protect the circuit, motor, heating wire and other components of the device from overload. When the components are overloaded or short-circuited, the power supply is automatically cut off to prevent damage to the components and extend the service life of the device. When the formaldehyde leak sensor detects a formaldehyde gas leak during operation, it immediately sends a signal to the PLC controller. The PLC controller then activates the audible and visual alarm and simultaneously cuts off the gas valve and power supply to prevent the leak from escalating.

[0033] This invention provides a method for using a formaldehyde gas generator using the permeation gas mixing method. Based on the aforementioned formaldehyde gas generator using the permeation gas mixing method, the steps include: Step 1: Preliminary preparation: Inject formaldehyde solution into the formaldehyde liquid storage tank 22, check the connection status of each unit, ensure that the gas path is well sealed and the circuit connection is normal, set the preset parameters through the operation panel, start the device, and initialize each unit of the PLC controller. Step 2: Temperature and humidity control adjustment: The temperature and humidity control unit is activated to stabilize the temperature and humidity of the temperature and humidity chamber 24 at the preset values; Step 3: Formaldehyde Permeation: The permeation unit is activated to permeate the formaldehyde solution and generate formaldehyde vapor; Step 4: Carrier gas distribution and mixing: The carrier gas distribution unit is activated to mix and dilute the generated formaldehyde vapor; Step 5: Formaldehyde gas collection: The formaldehyde gas collection unit moves to collect the generated formaldehyde gas; Step Six: Throughout the entire operation of the device, the detection and control unit and the safety protection unit remain in operation to detect and control the entire device's operation and provide safety protection.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A permeation gas-mixing method formaldehyde gas generating apparatus characterized by: Includes a frame (1), the frame (1) is provided with a permeation unit, a constant temperature and humidity control unit, a carrier gas distribution unit, a detection and control unit, a gas path connection unit and a safety protection unit, the permeation unit is located inside the constant temperature and humidity control unit, and the end of the permeation unit is connected to the carrier gas distribution unit; The permeation unit is used to generate formaldehyde vapor through permeation; the constant temperature and humidity control unit provides a suitable environment for generating formaldehyde vapor; the carrier gas distribution unit is used for gas distribution and dilution to facilitate the generation of a suitable concentration of formaldehyde gas; the detection and control unit is used to detect and control the operation of the entire device; the gas path connection unit is used to connect the corresponding unit components; and the safety protection unit is used to provide safety protection for the entire device and improve the safety of its use.

2. The permeation gas-mixing method formaldehyde gas generator according to claim 1, characterized by: The permeation unit includes a permeation chamber (56), which contains several permeation chambers (60). A fixed pipe (75) is connected to the top outlet of each permeation chamber (60), and a connector (35) is connected to the fixed pipe (75). A modified permeation membrane (59) is installed inside the connector (35). The modified permeation membrane (59) is located at the top of the permeation chamber (60). A liquid check valve (62) is connected to the lower inlet of the permeation chamber (60). The liquid check valve (62) is connected to the top of the liquid output pipe (69), which is connected to an ultrasonic vibrator (27). The ultrasonic vibrator (27) is mounted on the frame (1). The formaldehyde liquid storage tank (22) is connected to one end of an infusion tube (25) and the other end of the infusion tube (25) is connected to a liquid precision metering pump (46). The liquid precision metering pump (46) is connected to the lower part of a liquid supply valve (45). The liquid supply valve (45) is installed at the lower part of a formaldehyde liquid storage tank (22). A liquid temperature sensor (17) for measuring the temperature of the formaldehyde liquid in the formaldehyde liquid storage tank (22) is installed on the formaldehyde liquid storage tank (22). A liquid level sensor (30) for measuring the liquid level of the formaldehyde liquid in the formaldehyde liquid storage tank (22) is installed on the formaldehyde liquid storage tank (22). An injection valve (16) is provided at the top of the formaldehyde liquid storage tank (22). A permeation ultrasonic vibrator (70) is installed on the permeation tank (56). A rectangular channel is machined through the middle of the infiltration box (56), and the infiltration ultrasonic vibrator (70) is installed at the bottom of the rectangular channel; The permeation chambers (60) are arranged in an array within the permeation box (56) and form a rectangular shape; The ultrasonic vibrator (27) has several connection channels. The infusion tube (25) and the liquid output tube (69) are connected through the connection channels, and the infusion tube (25) and the modified permeation membrane (59) are connected one-to-one. The formaldehyde liquid storage tank (22) is supported and installed at the bottom by a bottom support ring (23). The bottom support ring (23) is installed on the mounting plate (20). The mounting plate (20) is connected to the side wall of the frame (1). An upper cover ring (21) is pressed on the upper side of the formaldehyde liquid storage tank (22). The upper cover ring (21) is connected to the nut plate (18). The nut plate (18) is detachably connected to the mounting plate (20). The inner surfaces of the bottom support ring (23) and the upper cover ring (21) are provided with anti-slip material.

3. The formaldehyde gas generating device using the permeation gas mixing method according to claim 2, characterized in that: The inner side of the connector (35) is provided with an annular protrusion to press the modified permeation membrane (59) so that the modified permeation membrane (59) is pressed between the annular protrusion and the fixed tube (75). A certain amount of exhaust space is reserved on the upper side of the annular protrusion. The modified permeation membrane (59) is a PDMS / PVDF composite membrane modified with hydrophobic TiO2 nanoparticles. PVDF serves as the base membrane to ensure the membrane's mechanical strength and permeability. PDMS serves as the intermediate layer to enhance formaldehyde permeability. The hydrophobic TiO2 nanoparticles serve as the surface modifier to effectively inhibit the adsorption and polymerization of formaldehyde molecules on the membrane surface, reduce membrane fouling, extend the service life of the modified permeation membrane (59), and improve the stability of formaldehyde permeation.

4. The formaldehyde gas generating device using the permeation gas mixing method according to claim 3, characterized in that: The constant temperature and humidity control unit includes a constant temperature and humidity chamber (24), which is mounted on the upper side of the frame (1) via constant temperature and humidity chamber support legs (71). A rectangular frame (55) is connected to the constant temperature and humidity chamber (24), and a permeation chamber (56) is connected to the rectangular frame (55). The lower part of the permeation chamber (56) is flush with the bottom of the constant temperature and humidity chamber (24). A constant temperature component is connected to the constant temperature and humidity chamber (24). The constant temperature component includes electric heating wires (64) evenly installed on the inner surface of the constant temperature and humidity chamber (24). Semiconductor cooling (65) is installed on the inner surface of the constant temperature and humidity chamber (24) between the electric heating wires (64). The constant temperature and humidity chamber (24) has several exhaust channels (57) through it. A miniature fan (58) is installed in the exhaust channel (57). A gas flow valve (32) is connected to the outlet of the exhaust channel (57). The constant temperature and humidity chamber (24) is connected to a humidity control component. The humidity control component includes a water-absorbing cotton insert plate (26) inserted into the constant temperature and humidity chamber (24). The inner surface of the water-absorbing cotton insert plate (26) is connected to water-absorbing cotton (66). Several atomizing channels (68) are processed through the rectangular frame (55). An atomizing nozzle (67) is connected to the lower outlet of the atomizing channel (68). The upper inlet of the atomizing channel (68) is connected to one end of the atomizing gas pipe (33). The other end of the atomizing gas pipe (33) is connected to the outlet of the atomizing three-way pipe (43). The inlet of the atomizing three-way pipe (43) is connected to the atomizer (44). The atomizer (44) is connected to the frame (1). An atomizing one-way valve (42) is connected in series between the outlet of the atomizing three-way pipe (43) and the atomizing gas pipe (33). The constant temperature and humidity chamber (24) is equipped with a humidity sensor (61) and a temperature sensor (63) for monitoring the humidity and temperature inside the constant temperature and humidity chamber (24); The exhaust channels (57) are all located on the side wall of the constant temperature and humidity chamber (24), and several are provided on each side wall; The inner surface of the constant temperature and humidity chamber (24) is provided with heat insulation material.

5. A formaldehyde gas generating device using the permeation gas mixing method according to claim 4, characterized in that: The carrier gas distribution unit includes a carrier gas tank (2) mounted on the frame (1). An air supply valve (4) is connected to the upper outlet of the carrier gas tank (2). One end of an air supply pipe (5) is connected to the air supply valve (4). The other end of the air supply pipe (5) is connected to the inlet of a filter (53). A connecting pipe (54) connects the outlet of the filter (53) to the inlet of the dryer (52). One end of an output pipe (7) is connected to the outlet of the dryer (52). (7) A carrier gas tee (37) is connected to the other end. The two outlets of the carrier gas tee (37) are respectively connected to a dilution gas path precision flow controller (36) and a bottom gas path precision flow controller (38). One end of a bottom gas path branch pipe (39) is connected to the bottom gas path precision flow controller (38). The other end of the bottom gas path branch pipe (39) is connected to a bottom gas one-way valve (49). The bottom gas one-way valve (49) is installed on one inlet of the mixing tee (47). An adjustable throttle valve (40) is connected in series on the bottom gas branch pipe (39). One end of a permeation branch pipe (15) is connected to the connector plug (35). The other end of the permeation branch pipe (15) is connected to the manifold pipe (14). A shut-off valve (31) is connected in series on the permeation branch pipe (15). The other end of the manifold pipe (14) is connected to a gas-gathering check valve (48). The gas-gathering check valve (48) is installed on another inlet of the mixing tee pipe (47). A permeate flow sensor (41) is connected to the pipe (14). The outlet of the mixing tee (47) is connected to the lower part of the gas buffer cylinder (72). A mixing box (13) is connected to the upper part of the gas buffer cylinder (72). A spiral mixing blade (50) is installed inside the mixing box (13). The gas buffer cylinder (72) is connected between the mixing box (13) and the dilution gas path precision flow controller (36). A dilution check valve (51) is connected in series on the gas buffer cylinder (72). Two spiral mixing blades (50) are provided, and the inner and outer layers are nested. The spiral mixing blades (50) are located on the upper side of the outlet of the gas buffer cylinder (72). The dryer (52) and the filter (53) are installed in the mounting box (6), which is mounted on the frame (1); The gas buffer cylinder (72) and the inner wall of the mixing box (13) are coated with a fluorocarbon anti-polymerization coating; A safety valve (3) is installed on the carrier gas tank (2), and a carrier gas temperature sensor (74) is installed on the carrier gas tank (2); The mixing chamber (13) is mounted on the frame (1) via a mixing chamber base (28).

6. The formaldehyde gas generating device using the permeation gas mixing method according to claim 5, characterized in that: The mixing chamber (13) is connected to a formaldehyde gas collection unit at the top. The formaldehyde gas collection unit includes a collection check valve (34) connected to the outlet at the top of the mixing chamber (13). A collection pipe (11) is connected between the collection check valve (34) and the collection pressure gauge (10). The collection pressure gauge (10) is installed on the upper part of the collection valve (9). The collection valve (9) is installed on the upper part of the collection tank (8). The collection tank (8) is installed on the frame (1). A formaldehyde concentration sensor (12) is connected to the collection pipe (11).

7. A formaldehyde gas generating device using the permeation gas mixing method according to claim 6, characterized in that: The detection and control unit includes a control console (29) mounted on the frame (1), and a PLC controller is provided in the control console (29). The PLC controller is connected to the electrical components in the device. The detection unit also includes a data acquisition module and an execution module. The data acquisition module is used to collect relevant operating parameters, organize and store the data, and display it in real time through the display screen of the operation panel. It also supports data export for easy analysis and calibration later. The execution module is used to receive control commands from the PLC controller and adjust the corresponding operating parameters. The detection and control unit also includes a remote control module that supports wireless remote connection. Staff can use mobile phones, computers and other terminals to view the device's operating status and adjust operating parameters in real time, thereby achieving remote control and improving the ease of use of the device. It also features a parameter memory function, which can store multiple sets of commonly used gas mixing parameters, allowing for direct recall the parameters the next time they are used without the need for repeated settings.

8. A formaldehyde gas generating device using the permeation gas mixing method according to claim 7, characterized in that: The gas connection unit includes a pipe connecting the permeation unit and the carrier gas distribution unit, and also includes pipes in the carrier gas distribution unit and the formaldehyde gas collection unit. The pipes are coated with an anti-polymerization coating to inhibit the adsorption and polymerization of formaldehyde molecules on the inner wall of the pipes.

9. A formaldehyde gas generating device using the permeation gas mixing method according to claim 7, characterized in that: The safety protection unit includes a leakage detection module, an emergency handling module, and an overload protection module; The leakage detection module includes a formaldehyde leakage sensor and an audible and visual alarm device. The formaldehyde leakage sensor is evenly installed on the rack (1), at the gas connection point and near the control console (29) to detect whether formaldehyde leakage has occurred. The audible and visual alarm device is located at the corresponding position on the rack (1). The emergency treatment module includes an activated carbon adsorption box and an emergency exhaust fan. The activated carbon adsorption box is located inside the frame and is used to adsorb leaked formaldehyde gas to avoid polluting the environment and harming human health. The emergency exhaust fan is installed at the corresponding position on the frame (1). The overload protection module is used to protect the circuit, motor, heating wire and other components of the device from overload. When the components are overloaded or short-circuited, the power supply is automatically cut off to prevent damage to the components and extend the service life of the device.

10. A method of using a formaldehyde gas generating device using the permeation gas mixing method, based on the formaldehyde gas generating device using the permeation gas mixing method described in claim 9, characterized in that: step include: Step 1: Preliminary preparation: Inject formaldehyde solution into the formaldehyde liquid storage tank (22), check the connection status of each unit, ensure that the gas path is well sealed and the circuit connection is normal, set the preset parameters through the operation panel, start the device, and initialize each unit of the PLC controller. Step 2: Temperature and humidity control adjustment: The temperature and humidity control unit is activated to stabilize the temperature and humidity of the temperature and humidity chamber (24) at the preset values; Step 3: Formaldehyde Permeation: The permeation unit is activated to permeate the formaldehyde solution and generate formaldehyde vapor; Step 4: Carrier gas distribution and mixing: The carrier gas distribution unit is activated to mix and dilute the generated formaldehyde vapor; Step 5: Formaldehyde gas collection: The formaldehyde gas collection unit moves to collect the generated formaldehyde gas; Step Six: Throughout the entire operation of the device, the detection and control unit and the safety protection unit remain in operation to detect and control the entire device's operation and provide safety protection.

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