Low-air-pressure VOC (volatile organic compound) testing device

Abstract

The invention discloses a low-pressure VOC (volatile organic compound) testing device which comprises a pressure-bearing heat-insulating box, and a testing cabin for placing a workpiece to be tested is arranged in the pressure-bearing heat-insulating box; the pressure relief pipe is arranged on the test cabin so as to be communicated with the pressure-bearing heat preservation box and the test cabin, and a pressure regulating valve is arranged on the pressure relief pipe; the pressure regulating device is used for regulating the air pressure of the pressure-bearing heat preservation box and comprises an air outlet pipeline which is communicated with the outside and the pressure-bearing heat preservation box, and a first control valve and a vacuum pump are sequentially arranged on the air outlet pipeline in the air flowing direction. According to the invention, different air pressure values can be simulated in the test chamber, so that a detection environment for detecting the volatilization rate of VOC pollutants under different air pressures is provided for a to-be-detected material or a to-be-detected workpiece.

Description

Technical Field

[0001] The present invention relates to the technical field of gas collection equipment, and in particular to a low-pressure VOC test device. Background Art

[0002] As people's living standards continue to improve, their requirements for living environments have also greatly increased. Many indoor materials and products now contain toxic substances such as formaldehyde. To protect people's health, it is necessary to test the release rate and release characteristics of volatile organic compounds (VOCs) such as benzene, toluene, and formaldehyde contained in indoor materials and products. In this way, qualified indoor materials and products can be obtained to provide people with a good living environment.

[0003] However, there is a lack of low-pressure VOC test devices on the market. Existing VOC test devices maintain a constant pressure within their test chambers, making it impossible to adjust the pressure within the chambers. Consequently, it is impossible to verify the reliability of various VOC-emitting materials or workpieces under varying pressures. Therefore, a low-pressure VOC test device with variable chamber pressure is needed. Summary of the Invention

[0004] The object of the present invention is to provide a low-pressure VOC test device to solve the problem that the existing low-pressure VOC test device cannot change the air pressure in the test chamber.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A low-pressure VOC test device, comprising:

[0007] A pressure-bearing and heat-insulating box, wherein a test chamber for placing a workpiece to be tested is provided in the pressure-bearing and heat-insulating box;

[0008] a gas input device for inputting clean gas into the test chamber; the gas input device includes a gas source and an air inlet pipe, the air inlet pipe connecting the gas source and the test chamber; the air inlet pipe is provided with a humidity control device for adjusting the humidity of the gas entering the test chamber; the air inlet pipe is provided with a flow monitoring device for observing the flow of clean gas passing through the air inlet pipe;

[0009] A pressure relief pipe is provided on the test chamber to connect the test chamber and the pressure-bearing insulation box, and a pressure regulating valve is provided on the pressure relief pipe to ensure that the test chamber is in a slightly positive pressure state;

[0010] A pressure sensing device, the pressure sensing device being provided in the pressure-bearing heat-insulating box and being used to detect the air pressure value of the pressure-bearing heat-insulating box;

[0011] A pressure regulating device for regulating the air pressure of the pressure-bearing and heat-insulating box, the pressure regulating device comprising an air outlet pipeline connecting the outside and the pressure-bearing and heat-insulating box, and a vacuum pump arranged on the air outlet pipeline;

[0012] When adjusting the air pressure in the test chamber, the flow rate of the clean gas input by the gas input device is first controlled as needed, and then the air pressure value of the pressure-bearing insulation box is adjusted; under the interaction of the vacuum pump, the adjustment of the pressure regulating valve, and the gas input device, the air pressure value of the pressure-bearing insulation box is slightly lower than the air pressure value of the test chamber;

[0013] A control system, wherein the control system is electrically connected to the pressure sensing device, the vacuum pump and the gas input device respectively, and the control system receives the air pressure value detected by the pressure sensing device. The control system controls the opening and closing or other operating modes of the vacuum pump according to the detected air pressure value and the set test chamber air pressure value.

[0014] Preferably, the flow monitoring device and the humidity control device are sequentially arranged on the air inlet pipe according to the flow direction of the gas.

[0015] Preferably, the flow monitoring device is located outside the pressure-bearing and heat-insulating box, and the humidity control device is located inside the pressure-bearing and heat-insulating box or outside the pressure-bearing and heat-insulating box.

[0016] Preferably, a VOC filter device is further provided on the pressure relief pipe; the pressure regulating valve and the VOC filter device are sequentially arranged on the pressure relief pipe according to the flow direction of the gas.

[0017] Preferably, it also includes a heater arranged in the pressure-bearing and heat-insulating box, an evaporator arranged in the pressure-bearing and heat-insulating box, and a circulation fan for driving the gas flow in the pressure-bearing and heat-insulating box.

[0018] Preferably, a stirring fan and a first magnetic seal motor for driving the stirring fan to rotate are installed in the test chamber.

[0019] Preferably, a heating pipe is provided on the side wall of the test chamber, and the heating pipe is located at the air inlet end of the stirring fan.

[0020] Preferably, the first magnetic seal motor is installed on the outer side wall of the test chamber, and the first magnetic seal motor is located in the pressure-bearing thermal insulation box.

[0021] Preferably, a space is provided between the outer side wall of the test chamber and the inner side wall of the pressure-bearing thermal insulation box.

[0022] Preferably, a bracket is provided at the bottom of the pressure-bearing thermal insulation box, and the test chamber is provided on the bracket;

[0023] The bracket is formed by welding round tubes.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The low-pressure VOC test device provided by the present invention is arranged in a pressure-bearing insulation box of a pressure-bearing insulation box through a test cabin, the test cabin is connected to the pressure-bearing insulation box through a pressure relief pipe, and a pressure-regulating valve is provided on the pressure relief pipe; the pressure-bearing insulation box is connected to the outside world through the pressure regulating device, and the vacuum pump in the pressure device extracts the gas from the pressure-bearing insulation box to change the air pressure value in the pressure-bearing insulation box, and then the gas in the test cabin is discharged into the pressure-bearing insulation box through the pressure regulating valve so that the air pressure in the test cabin is slightly higher than the air pressure in the pressure insulation box, thereby realizing the air pressure regulation in the test cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which the present invention can be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and objectives that can be achieved by the present invention.

[0028] Figure 1 A schematic structural diagram of a low-pressure VOC test device provided in Example 1 of the present invention;

[0029] Figure 2 This is a structural diagram of a low-pressure VOC test device provided in Example 2 of the present invention.

[0030] Illustration: 1. Pressure-bearing insulation box; 12. Pressure regulating device; 121. Air outlet pipe; 122. First control valve; 123. Vacuum pump; 13. Heater; 14. Evaporator; 15. Circulation fan;

[0031] 2. Test chamber; 22. Pressure relief pipe; 23. Pressure regulating valve; 24. VOC filter; 25. Stirring fan; 26. First magnetic seal motor; 27. Pressure sensing device; 28. Heating tube;

[0032] 3. Gas input device; 31. Air inlet pipe; 32. Humidity control device; 33. Flow monitoring device. DETAILED DESCRIPTION

[0033] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally located component.

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] The present invention provides a low-pressure VOC testing device that maintains a low pressure in a pressurized insulated box 1 and a test chamber 2. A gas input device 3 supplies clean gas to the test chamber 2, maintaining a slightly positive pressure via a pressure regulating valve 23 and a vacuum pump 123. This supports VOC testing of test materials at various pressures. This embodiment primarily regulates the low pressure in the pressurized insulated box 1 and the test chamber 2.

[0037] Example 1

[0038] See also Figure 1 An embodiment of the present invention provides a low-pressure VOC test device, including a pressure-bearing insulation box 1 and a test chamber 2.

[0039] The test chamber 2 is placed in the pressure-bearing thermal insulation box 1. The pressure-bearing thermal insulation box 1 is provided with an openable and closable door to facilitate the placement of the test chamber 2; the test chamber 2 is provided with an openable and closable door to facilitate the placement of the workpiece.

[0040] The test cabin 2 is provided with a pressure relief pipe 22 connected to the pressure-bearing insulation box 1, and a pressure regulating valve 23 is provided on the pressure relief pipe 22. The pressure regulating valve 23 is used to control the air pressure value of the test cabin 2 so that the air pressure of the test cabin 2 is slightly positive relative to the air pressure of the pressure-bearing insulation box 1.

[0041] The pressure regulating device 12 is used to adjust the air pressure in the pressurized insulation box 1. The pressure regulating device 12 includes an air outlet pipeline 121, on which a first control valve 122 and a vacuum pump 123 are sequentially arranged along the direction of gas flow. The first control valve 122 is used to close the air outlet pipeline 121 when exhaust is not required.

[0042] Specifically, the pressure regulating device 12 adjusts the air pressure value of the pressure-bearing and heat-insulating box 1 through the vacuum pump 123 , thereby changing the air pressure of the pressure-bearing and heat-insulating box 1 and the test chamber 2 .

[0043] Optionally, the low-pressure VOC test apparatus includes a gas input device 3 for supplying clean gas to the test chamber 2. The gas input device 3 includes a gas source and an air inlet pipe 31, which connects the gas source and the test chamber 2. The air inlet pipe 31 is provided with a humidity control device 32 for adjusting the humidity of the gas entering the test chamber 2. Specifically, the gas input device 3 is used to supply clean gas to the test chamber 2. By appropriately adjusting the flow rate of the input gas and the flow rate of gas passing through the pressure regulating valve 23, a stable testing environment can be maintained in the test chamber 2. It should be noted that the test chamber 2 maintains a slightly positive pressure via the gas input device 3 or the pressure regulating valve 23. When the pressure in the test chamber 2 needs to be increased, the flow rate of clean gas supplied by the gas input device 3 can be increased. When the pressure in the test chamber 2 needs to be decreased, the flow rate of clean gas supplied by the gas input device 3 into the test chamber 2 can be reduced, or the flow rate of gas passing through the pressure regulating valve 23 can be appropriately increased. It is worth noting that when adjusting the air pressure in the test chamber 2, it is necessary to first adjust the air pressure in the pressure-bearing and insulated box 1 to prevent the air pressure in the pressure-bearing and insulated box 1 from being too high, which would cause gas to flow back into the test chamber 2. Specifically, due to the interaction of the vacuum pump 123, the pressure-regulating valve 23, and the gas input device 3, the air pressure in the pressure-bearing and insulated box 1 is slightly higher than the air pressure in the test chamber 2.

[0044] Optionally, a flow monitoring device 33 is provided on the air inlet pipe 31 to monitor the flow of clean gas passing through it. The flow monitoring device 33 and the humidity control device 32 are sequentially arranged on the air inlet pipe 31 in the direction of gas flow. Specifically, the flow monitoring device 33 is used to instruct personnel to increase or decrease the pressure, thereby improving the accuracy of adjusting the air pressure value in the test chamber 2. Furthermore, the flow monitoring device 33 is arranged before the humidity control device 32 to prevent the humidity-controlled gas from affecting the actual flow of clean gas input. It should be noted that the humidity control device 32 can be used to both increase the moisture content of the passing gas and to dry the passing gas.

[0045] Optionally, the low-pressure VOC test device also includes a control system and a pressure sensing device 27 for detecting the air pressure value of the pressure-bearing insulation box 1; the pressure sensing device 27 is arranged in the pressure-bearing insulation box 1; the control system is electrically connected to the pressure sensing device 27, the vacuum pump 123 and the gas input device 3 respectively. Specifically, the control system receives the air pressure value detected by the pressure sensing device 27, and the control system controls the opening and closing of the vacuum pump 123 according to the detected air pressure value and the set test chamber air pressure value. When the detected air pressure value is greater than the set test chamber air pressure value, the vacuum pump 123 turns on and draws air to the outside to reduce the air pressure value of the pressure-bearing insulation box 1; when the detected air pressure value is less than the set test chamber air pressure value, the vacuum pump 123 turns off. In addition, the control system controls the gas input device 3 to maintain a stable flow rate to input clean gas into the test chamber 2.

[0046] Optionally, a VOC filter device 24 is provided on the pressure relief pipe 22; the pressure regulating valve 23 and the VOC filter device 24 are sequentially arranged on the pressure relief pipe 22 in the direction of gas flow. The VOC filter device 24 is used to absorb VOC gases and prevent VOC gases in the pressurized insulation box 1 from entering the test chamber 2 and affecting the detection effect in the test chamber 2.

[0047] Optionally, the low-pressure VOC test device further includes a heater 13 disposed in the pressurized thermal insulation box 1, an evaporator 14 disposed in the pressurized thermal insulation box 1, and a circulation fan 15 for driving the circulation of gas in the pressurized thermal insulation box 1. Specifically, the heater is used to adjust the temperature of the gas in the pressurized thermal insulation box 1, the evaporator 14 is used to adjust the humidity of the gas in the pressurized thermal insulation box 1, and the circulation fan 15 is used to drive the circulation of gas in the pressurized thermal insulation box 1 to improve the uniformity of the gas temperature.

[0048] Optionally, a heating tube 28 is provided on the side wall of the test chamber 2, located at the air inlet end of the stirring fan 25. The heating tube is used to compensate for the temperature of the gas within the test chamber 2. The gas heated by the heating tube is further improved in temperature uniformity after passing through the stirring fan 25, thereby preventing uneven temperatures within the test chamber 2 from affecting the VOC detection results and improving VOC detection accuracy. Furthermore, the stirring fan 25 is driven by a magnetically sealed motor, which helps improve sealing capabilities and prevent air leaks.

[0049] Optionally, a stirring fan 25 and a first magnetically sealed motor 26 for driving the stirring fan 25 are installed in the test chamber 2; the first magnetically sealed motor 26 is mounted on the outer wall of the test chamber 2 and is located within the pressurized thermal insulation box 1. Similarly, the first magnetically sealed motor 26 can effectively improve the sealing capability, preventing gas in the test chamber 2 from leaking along the motor shaft into the pressurized thermal insulation box 1.

[0050] A gap is provided between the outer wall of the test chamber 2 and the inner wall of the pressure-bearing thermal insulation box 1 , and a circulating fan 15 is provided in the gap to drive the gas to circulate around the test chamber 2 .

[0051] Optionally, a bracket is provided at the bottom of the pressure-bearing insulation box 1, and the test chamber 2 is provided on the bracket, and the bracket is formed by welding round tubes. The bracket formed by welding round tubes is conducive to reducing the resistance of gas flow and saving energy.

[0052] In this embodiment, the humidity control device 32 is provided in the pressure-bearing insulation box 1 , and the low-pressure VOC test device has a high degree of integration, which is beneficial to reducing the volume of the low-pressure VOC test device.

[0053] It should be noted that the various technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] It should be noted that the components mentioned in the above embodiments are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0055] Example 2

[0056] See also Figure 2 The main improvement of this embodiment over the first embodiment is that a separate cavity is provided on the outer wall of the pressurized thermal insulation box 1 to store the humidity control device 32. This prevents the humidity control device 32 from affecting the air pressure in the pressurized thermal insulation box 1 due to factors such as heat generation during actual operation. This helps to improve the air pressure stability of the test chamber 2.

[0057] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-pressure VOC test device, characterized in that: include: A pressure-bearing heat-insulating box (1), wherein a test chamber (2) for placing a workpiece to be tested is provided in the pressure-bearing heat-insulating box (1); A gas input device (3) for inputting clean gas into the test chamber (2); the gas input device (3) comprises a gas source and an air inlet pipe (31), the air inlet pipe (31) being in communication with the gas source and the test chamber (2); a humidity control device (32) for adjusting the humidity of the gas entering the test chamber (2) is provided on the air inlet pipe (31); and a flow monitoring device (33) for observing the flow of the clean gas passing through the air inlet pipe (31) is provided on the air inlet pipe (31); a pressure relief pipe (22) provided on the test chamber (2) to connect the test chamber (2) and the pressure-bearing thermal insulation box (1); a pressure regulating valve (23) provided on the pressure relief pipe (22); and the pressure regulating valve (23) is used to ensure that the test chamber (2) is in a slightly positive pressure state; a pressure sensing device (27), the pressure sensing device (27) being arranged in the pressure-bearing heat-insulating box (1) and being used to detect the air pressure value of the pressure-bearing heat-insulating box (1); a pressure regulating device (12) for regulating the air pressure of the pressure-bearing and heat-insulating box (1), the pressure regulating device (12) comprising an air outlet pipe (121) communicating with the outside and the pressure-bearing and heat-insulating box (1), and a vacuum pump (123) arranged on the air outlet pipe (121); When adjusting the air pressure of the test chamber (2), the flow rate of the clean gas inputted by the gas input device (3) is first controlled as required, and then the air pressure value of the pressure-bearing insulation box (1) is adjusted; under the interaction of the vacuum pump (123), the adjustment of the pressure regulating valve (23), and the gas input device (3), the air pressure value of the pressure-bearing insulation box (1) is slightly lower than the air pressure value of the test chamber (2); A control system is provided, wherein the control system is electrically connected to the pressure sensing device (27), the vacuum pump (123) and the gas input device (3), respectively, and the control system receives the air pressure value detected by the pressure sensing device (27). The control system controls the opening and closing or other operating modes of the vacuum pump (123) according to the detected air pressure value and the set test chamber air pressure value.

2. The low-pressure VOC test device according to claim 1, characterized in that: The flow monitoring device (33) and the humidity control device (32) are sequentially arranged on the air inlet pipe (31) according to the flow direction of the gas.

3. The low-pressure VOC test device according to claim 2, characterized in that: The flow monitoring device (33) is located outside the pressure-bearing and heat-insulating box (1), and the humidity control device (32) is located inside the pressure-bearing and heat-insulating box (1) or outside the pressure-bearing and heat-insulating box (1).

4. The low-pressure VOC test device according to claim 1, characterized in that: The pressure relief pipe (22) is also provided with a VOC filter device (24); the pressure regulating valve (23) and the VOC filter device (24) are sequentially arranged on the pressure relief pipe (22) according to the flow direction of the gas.

5. The low-pressure VOC test device according to claim 1, characterized in that: It also includes a heater (13) arranged in the pressure-bearing and heat-insulating box (1), an evaporator (14) arranged in the pressure-bearing and heat-insulating box (1), and a circulation fan (15) for driving the gas circulation in the pressure-bearing and heat-insulating box (1).

6. The low-pressure VOC test device according to claim 1, characterized in that: A stirring fan (25) and a first magnetic seal motor (26) for driving the stirring fan (25) to rotate are installed in the test chamber (2).

7. The low-pressure VOC test device according to claim 6, characterized in that: A heating pipe (28) is provided on the side wall of the test chamber (2), and the heating pipe (28) is located at the air inlet end of the stirring fan (25).

8. The low-pressure VOC test device according to claim 6, characterized in that: The first magnetic seal motor (26) is installed on the outer side wall of the test chamber (2), and the first magnetic seal motor (26) is located in the pressure-bearing thermal insulation box (1).

9. The low-pressure VOC test device according to claim 1, characterized in that: A gap is provided between the outer side wall of the test chamber (2) and the inner side wall of the pressure-bearing thermal insulation box (1).

10. The low-pressure VOC test device according to claim 1, characterized in that: A bracket is provided at the bottom of the pressure-bearing thermal insulation box (1), and the test chamber (2) is provided on the bracket; The bracket is formed by welding round tubes.

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