Air pressure detection alarm and explosion-proof device for water vapor permeability tester

Abstract

The utility model relates to an air pressure detection alarm and explosion-proof device for a water vapor permeability tester. The air pressure detection alarm and explosion-proof device comprises a partial pressure meter, a valve, an air pressure detector, an air pressure alarm device, an explosion-proof box, a guide plate and a drying agent cloth plate, the spiral flow guide device has the beneficial effects that gas can be forced to flow spirally, the flow guide efficiency is improved, the gas retention time is prolonged, and the contact frequency of the gas and a drying agent is increased; airflow short circuit caused by a single guide plate can be avoided; the airflow reaching the drying agent is gentle and slow so as to avoid local caking of the drying agent due to contact with too much humid gas in a short time; gradient filtration is formed, and local airflow short circuit caused by small holes blocked by large particles is avoided; gradient filtration is formed, local airflow short circuit caused by the fact that small holes are blocked by large particles is avoided, and the contact time of gas and a drying agent can be prolonged by about 30% or above; and an alarm can be given and the opening degree of the valve can be adjusted in time, so that the test safety is guaranteed.

Description

Technical Field

[0001] This utility model belongs to the technical field of water vapor transmission rate tester, and in particular relates to a gas pressure detection alarm and explosion-proof device for a water vapor transmission rate tester. Background Technology

[0002] With the rapid development of the polymer film industry, the gas permeability of films has received considerable attention. Water vapor permeability is a commonly used reference indicator for the gas permeability of films, and there are increasingly more scenarios requiring testing of water vapor permeability.

[0003] MOCON PERMATRAN- The 3 / 34H is a device specifically designed for testing the water vapor transmission rate of high-barrier and low-barrier films and packaging materials. It employs an infrared modulation sensor system compliant with ASTM F129 standards to detect the water vapor transmission rate of the film. It also utilizes nitrogen circulation sealing technology to eliminate absolute zero points during testing, thus shortening the testing time. To ensure the accuracy of the test results, nitrogen carrier gas is introduced into the MOCON PERMATRAN- The instrument needs to be dried before use (3 / 34H), therefore, it should be dried before use (MOCON PERMATRAN-). The 3 / 34H equipment has a gas drying tube installed at the air inlet. Existing drying tubes are mostly made of transparent high-strength resin, which often leads to excessive internal pressure and potential bursting during use. Therefore, the MOCON PERMATRAN-... When using a 3 / 34H device to test water vapor transmission rate, the safety of the experiment is difficult to guarantee.

[0004] In addition, there is a phenomenon of desiccant accumulation in the existing drying tubes, which means that the gas can easily bypass the desiccant and fail to achieve the drying effect, also known as the "channeling" phenomenon. Utility Model Content

[0005] To ensure experimental safety when testing the water vapor transmission rate of high-barrier films, low-barrier films, and packaging materials, this invention designs a gas pressure detection alarm and explosion-proof device for a gas drying tube water vapor transmission rate tester. The device includes: a pressure gauge, a valve, a pressure detector, a pressure alarm device, an explosion-proof box, a guide plate, and a desiccant cloth plate.

[0006] This water vapor transmission rate tester uses a pressure detection alarm and explosion-proof device. The water vapor transmission rate tester is equipped with a matching drying tube and a control unit. An external gas supply device is connected to the drying tube through a gas pipeline, which is equipped with a valve. The drying tube is connected to the water vapor transmission rate tester through another gas pipeline. The tester includes: a pressure gauge, a valve, a pressure detector, a pressure alarm device, an explosion-proof box, a baffle plate, and a desiccant cloth plate. The control unit is electrically connected to the pressure gauge, the valve, the pressure detector, and the pressure alarm device.

[0007] The pressure gauge is installed on the gas pipeline connected to the inlet end of the drying tube. The pressure gauge is used to monitor the gas pressure before entering the drying tube according to the instructions of the control unit.

[0008] The drying tube is equipped with a pressure detector, which is used to detect the air pressure inside the drying tube according to the instructions of the control unit.

[0009] The drying tube is also equipped with a matching air pressure alarm device, which is used to emit a buzzer alarm sound according to the instructions of the control unit;

[0010] The drying tube is placed in a sealed explosion-proof box. Both ends of the explosion-proof box have through holes for gas pipelines, and a sealing element is installed between the through holes and the gas pipelines.

[0011] Both the inlet and outlet ends of the drying tube are equipped with arc-shaped guide plates, which are symmetrically distributed along the length of the drying tube. The guide plates are set at an angle of 30° to 45° with the airflow direction (forcing the gas to flow in a spiral manner, improving the guiding efficiency, extending the gas residence time, and increasing the contact frequency between the gas and the desiccant). The guide plate on the inlet side is fixedly connected to the top inner wall of the drying tube, and its lower end is a certain distance away from the bottom inner wall of the drying tube. The guide plate on the outlet side is fixedly connected to the bottom inner wall of the drying tube, and its upper end is a certain distance away from the top inner wall of the drying tube (the two guide plates are symmetrically distributed, and the double-layer guiding structure can avoid airflow short-circuiting caused by a single guide plate. Since the guide plates are arranged at an inclined angle with the airflow direction, the airflow reaches the desiccant only after being guided by the guide plates, making the airflow reaching the desiccant more gentle and slower to avoid the desiccant coming into contact with too much moist gas in a short time and causing local agglomeration). The gas forms an S-shaped airflow path along the guide plates inside the drying tube.

[0012] At least two desiccant cloth plates are arranged at different heights along the airflow direction on the inner wall of the drying tube. The desiccant cloth plates are evenly distributed with vent holes with a pore size smaller than the particle size of the desiccant. A certain thickness of desiccant is arranged on the desiccant cloth plates to form a desiccant layer. The particle size of the desiccant arranged on the desiccant cloth plates decreases as the height of the desiccant cloth plates decreases. Each layer is filled with desiccant of different particle sizes (fine particles in the upper layer and coarse particles in the lower layer), forming a gradient filtration to avoid local airflow short circuit caused by large particles clogging small holes.

[0013] Preferably, all deflectors are elliptical in shape and have a thickness of 1–2 mm.

[0014] As a preferred embodiment, the guide vanes are set at a 45° angle to the airflow direction; the two guide vanes are respectively located at 1 / 3 of the distance from the left end of the drying tube and at 1 / 3 of the distance from the right end of the drying tube.

[0015] Preferably, the control unit is used to send a gas pressure detection command to the pressure gauge; to send a gas pressure detection command to the pressure detector; and to determine whether the gas pressure before entering the drying tube and the gas pressure inside the drying tube exceed the set value. If at least one of the gas pressure before the drying tube and the gas pressure inside the drying tube exceeds the set value, the control unit sends an alarm command to the pressure alarm device and an opening adjustment command to the valve.

[0016] The pressure gauge is used to send the measured gas pressure of the gas before it enters the drying tube to the control unit;

[0017] The pressure detector is used to send the measured air pressure inside the drying tube to the control unit;

[0018] The valve is used to adjust its own opening degree according to the opening degree adjustment command, thereby controlling the gas flow rate entering the drying tube.

[0019] The beneficial effects of this utility model are:

[0020] The present invention features at least two guide plates at an angle of 30° to 45° to the airflow direction. The gas forms an S-shaped airflow path along the guide plates inside the drying tube, which forces the gas to flow in a spiral motion, improving the guiding efficiency, extending the gas residence time, and increasing the contact frequency between the gas and the desiccant. The at least two guide plates are symmetrically distributed vertically, and the multi-layer guiding structure can avoid airflow short-circuiting caused by a single guide plate. Since the guide plates are arranged at an inclined angle to the airflow direction, the airflow reaches the desiccant only after being guided by the guide plates, making the airflow reaching the desiccant more gentle and slower to avoid the desiccant coming into contact with too much humid gas in a short time and causing local agglomeration.

[0021] This invention features at least two desiccant cloth plates, each filled with desiccant of different particle sizes (fine particles on top, coarse particles on the bottom) to form a gradient filter and prevent local airflow short circuits caused by large particles clogging small pores.

[0022] The particle size of the desiccant arranged on the desiccant cloth plate of this utility model decreases as the height of the desiccant cloth plate decreases, avoiding the "channeling" phenomenon caused by the accumulation of desiccant in traditional drying tubes, where gas bypasses the desiccant and passes directly through. The multi-layer desiccant cloth plate structure and the guide plate designed in this utility model can increase the contact time between gas and desiccant by more than 30%.

[0023] This invention also includes a pressure alarm device that emits a buzzer alarm when at least one of the gas pressure before the drying tube or the gas pressure inside the drying tube exceeds a set value. The valve can also adaptively adjust its opening to regulate the gas flow rate into the drying tube. The drying tube is placed in a sealed explosion-proof enclosure to prevent environmental and personnel damage should the tube burst due to excessive pressure. The explosion-proof enclosure has a simple structure and is a simple and economical safety protection device. Attached Figure Description

[0024] Figure 1 A schematic diagram of the drying tube connected to the air inlet of the water vapor transmission rate tester;

[0025] Figure 2 Schematic diagram of air pressure detection alarm and explosion-proof device for water vapor transmission rate tester;

[0026] Figure 3 This is a schematic diagram of the guide plate and desiccant cloth plate installed inside the drying tube according to this utility model;

[0027] Figure 4 This is a schematic diagram of the control part of this utility model.

[0028] Explanation of reference numerals in the attached diagram: 1. Drying tube; 2. Pressure gauge; 3. Gas pipeline; 4. Desiccant; 5. Explosion-proof box; 6. Pressure alarm device; 7. Pressure detector; 8. Desiccant plate; 9. Desiccant layer; 10. Detailed Implementation

[0029] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that, for those skilled in the art, several modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0030] As one embodiment, a pressure detection alarm and explosion-proof device for a water vapor transmission rate tester, such as... Figures 1 to 4 As shown, the water vapor transmission rate tester is equipped with a matching drying tube 1 and a control unit. An external gas supply device is connected to the drying tube 1 through a gas pipeline 3, which is equipped with a valve. The drying tube 1 is connected to the water vapor transmission rate tester through another gas pipeline 3, including: a pressure gauge 2, a valve, a pressure detector 7, a pressure alarm device 6, an explosion-proof box 5, an elliptical guide plate 8 (2mm thick), and a desiccant cloth plate 9. The guide plate 8 is set at a 45° angle to the airflow direction. The two guide plates 8 are respectively located at 1 / 3 of the distance from the left end of the drying tube 1 and at 1 / 3 of the distance from the right end of the drying tube 1.

[0031] The control unit is electrically connected to the pressure gauge 2, the valve, the pressure detector 7, and the pressure alarm device 6. The control unit is used to send a gas pressure detection command to the pressure gauge 2; to send a gas pressure detection command to the pressure detector 7; and to determine whether the gas pressure before entering the drying tube 1 and the gas pressure inside the drying tube exceed the set value. If at least one of the gas pressure before entering the drying tube 1 and the gas pressure inside the drying tube exceeds the set value, the control unit sends an alarm command to the pressure alarm device 6 and an opening adjustment command to the valve. The valve adjusts its own opening according to the opening adjustment command, thereby controlling the gas flow rate entering the drying tube.

[0032] The pressure gauge 2 is installed on the gas pipeline 3 connected to the gas inlet end of the drying tube 1. The pressure gauge 2 is used to monitor the gas pressure before entering the drying tube 1 according to the instructions of the control unit. The pressure gauge 2 is used to send the measured gas pressure before entering the drying tube 1 to the control unit.

[0033] The drying tube 1 is equipped with a pressure detector 7. The pressure detector 7 is used to detect the pressure inside the drying tube 1 according to the instructions of the control unit. The pressure detector 7 is used to send the measured pressure inside the drying tube to the control unit.

[0034] The drying tube 1 is also equipped with a matching air pressure alarm device 6, which is used to emit a buzzer alarm sound according to the instructions of the control unit.

[0035] The drying tube 1 is placed in a sealed explosion-proof box 5. Both ends of the explosion-proof box 5 are provided with through holes for gas pipelines 3, and a sealing element is provided between the through holes and the gas pipelines 3.

[0036] Both the inlet and outlet ends of the drying tube 1 are equipped with arc-shaped guide plates 8. The two guide plates 8 are symmetrically distributed along the length of the drying tube 1, and are set at an angle of 30° to 45° to the airflow direction (forcing the gas to flow in a spiral pattern, improving the guiding efficiency, extending the gas residence time, and increasing the contact frequency between the gas and the desiccant). The guide plate 8 on the inlet side is fixedly connected to the top inner wall of the drying tube 1, and its lower end is a certain distance from the bottom inner wall of the drying tube 1; the guide plate 8 on the outlet side is fixedly connected to the top inner wall of the drying tube 1. The bottom inner wall of the fixed connection to the drying tube 1 is connected and its upper end is a certain distance away from the top inner wall of the drying tube 1 (two guide plates are symmetrically distributed above and below, and the double-layer guide structure can avoid airflow short-circuiting caused by a single guide plate; since the guide plates are arranged at an inclined angle to the airflow direction, the airflow reaches the desiccant after being guided by the guide plates, so that the airflow reaching the desiccant is relatively gentle and slow to avoid the desiccant coming into contact with too much humid gas in a short time and causing local agglomeration); the gas forms an S-shaped airflow path along the guide plate 8 in the drying tube 1;

[0037] At least two desiccant plates 9 are arranged at different heights along the airflow direction on the inner wall of the drying tube 1. Ventilation holes with a pore size smaller than that of the desiccant 4 are evenly distributed on the desiccant plates 9. A desiccant 4 of a certain thickness is arranged on the desiccant plates 9 to form a desiccant layer 10. The particle size of the desiccant 4 arranged on the desiccant plates 9 decreases as the height of the desiccant plates 9 decreases. Each layer is filled with desiccant of different particle sizes (fine particles in the upper layer and coarse particles in the lower layer) to form a gradient filter and avoid local airflow short circuit caused by large particles clogging small holes.

[0038] When the water vapor transmission rate tester uses air pressure detection alarm and explosion-proof device during operation:

[0039] The control unit sends a gas pressure detection command to the pressure gauge 2 and a gas pressure detection command for the inside of the drying tube to the pressure detector 7. The pressure gauge 2 monitors the gas pressure before entering the drying tube 1 according to the command of the control unit and sends the measured gas pressure before entering the drying tube 1 to the control unit. The pressure detector 7 detects the gas pressure inside the drying tube 1 according to the command of the control unit and sends the measured gas pressure inside the drying tube to the control unit. The control unit determines whether the gas pressure before entering the drying tube 1 and the gas pressure inside the drying tube exceed the set value. If at least one of the gas pressure before entering the drying tube 1 and the gas pressure inside the drying tube exceeds the set value, an alarm command is sent to the pressure alarm device 6 and an opening adjustment command is sent to the valve. The alarm device 6 emits a buzzer alarm sound. The valve adjusts its opening according to the opening adjustment command, thereby controlling the gas flow rate into the drying tube.

[0040] After the carrier nitrogen enters the drying tube 1 through the gas pipeline 3, its flow direction is changed by the first guide plate 8. From the airflow gap between the first guide plate 8 and the bottom of the drying tube 1, it passes through the through holes on the desiccant cloth plate 9 on which the desiccant is arranged from bottom to top, and comes into contact with the desiccant layer 10 to dry the gas. Then, it flows out of the drying tube 1 through the airflow gap between the second guide plate 8 and the top of the drying tube 1, and is supplied to the water vapor transmission rate tester through the gas pipeline 3 connected to the drying tube 1. This realizes the drying of the carrier nitrogen before it enters the water vapor transmission rate tester, ensuring the safety of the experiment.

Claims

1. A pressure detection alarm and explosion-proof device for a water vapor transmission rate tester, wherein the water vapor transmission rate tester is equipped with a matching drying tube (1) and a control unit, and an external gas supply device is connected to the drying tube (1) through a gas pipeline (3), the gas pipeline (3) being equipped with a valve; the drying tube (1) is connected to the water vapor transmission rate tester through another gas pipeline (3), characterized in that, include: The control unit is electrically connected to the pressure gauge (2), valve, pressure detector (7), pressure alarm device (6), explosion-proof box (5), deflector plate (8), and desiccant cloth plate (9). The pressure gauge (2) is installed on the gas pipeline (3) connected to the gas inlet end of the drying tube (1). The pressure gauge (2) is used to monitor the gas pressure of the gas before entering the drying tube (1) according to the instructions of the control unit. The drying tube (1) is equipped with the air pressure detector (7), which is used to detect the air pressure inside the drying tube (1) according to the instructions of the control unit; The drying tube (1) is also equipped with a matching air pressure alarm device (6), which is used to emit a buzzer alarm sound according to the instructions of the control unit. The drying tube (1) is placed inside the explosion-proof box (5). Both ends of the explosion-proof box (5) are provided with through holes for gas pipelines (3). A sealing element is provided between the through holes and the gas pipelines (3). The drying tube (1) has an arc-shaped guide plate (8) at both the inlet and outlet ends. The two guide plates (8) are symmetrically distributed along the length of the drying tube (1). The guide plates (8) are set at an angle of 30° to 45° with the airflow direction. The guide plate (8) on the inlet side is fixedly connected to the top inner wall of the drying tube (1) and its lower end is a certain distance away from the bottom inner wall of the drying tube (1). The guide plate (8) on the outlet side is fixedly connected to the bottom inner wall of the drying tube (1) and its upper end is a certain distance away from the top inner wall of the drying tube (1). The gas forms an S-shaped airflow path along the guide plate (8) inside the drying tube (1). At least two desiccant cloth plates (9) are arranged at different heights along the airflow direction on the inner wall of the drying tube (1). Ventilation holes with a pore size smaller than that of the desiccant (4) are evenly distributed on the desiccant cloth plate (9). A desiccant (4) of a certain thickness is arranged on the desiccant cloth plate (9) to form a desiccant layer (10). The particle size of the desiccant (4) arranged on the desiccant cloth plate (9) decreases as the height of the desiccant cloth plate (9) decreases.

2. The water vapor permeability tester with gas pressure detection alarm and explosion-proof device according to claim 1, characterized in that: All the guide plates (8) are elliptical in shape, and the thickness of each guide plate (8) is 1 to 2 mm.

3. The water vapor permeability tester with gas pressure detection alarm and explosion-proof device according to claim 2, characterized in that: The guide plate (8) is set at a 45° angle to the airflow direction; the two guide plates (8) are respectively located at 1 / 3 of the distance from the left end of the drying tube (1) and at 1 / 3 of the distance from the right end of the drying tube (1).

4. The air pressure detection alarm and explosion-proof device for the water vapor transmission rate tester according to claim 1, characterized in that: The control unit is used to send a gas pressure detection command to the pressure gauge (2); to send a gas pressure detection command inside the drying tube to the pressure detector (7); and to determine whether the gas pressure before entering the drying tube (1) and the gas pressure inside the drying tube exceed the set value. If at least one of the gas pressure before the drying tube (1) and the gas pressure inside the drying tube exceeds the set value, it is used to send an alarm command to the pressure alarm device (6) and send an opening adjustment command to the valve. The pressure gauge (2) is used to send the measured gas pressure of the gas before it enters the drying tube (1) to the control unit; The pressure detector (7) is used to send the measured pressure inside the drying tube to the control unit; The valve is used to adjust its own opening degree according to the opening degree adjustment command.

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