Formaldehyde gas detection device

Abstract

The utility model relates to the technical field of formaldehyde gas detection, in particular to a formaldehyde gas detection device which comprises a formaldehyde test instrument and a calibration device, a calibration opening and an exhaust opening are formed in the air outlet end of the formaldehyde testing instrument, and a switching valve communicated with the calibration opening and the exhaust opening is arranged in the formaldehyde testing instrument; the calibration device comprises a conversion chamber and a carbon dioxide detector used for detecting the concentration of carbon dioxide generated in the conversion chamber, an inner cavity pipeline of the conversion chamber is connected with a calibration opening, and catalytic plates are arranged in an inner cavity of the conversion chamber at intervals in the gas flow direction. According to the utility model, the real-time concentration of formaldehyde can be measured in a field environment, so that the calibration of a formaldehyde testing instrument can be reliably carried out.

Description

Technical Field

[0001] The utility model relates to the technical field of formaldehyde gas detection, in particular to a formaldehyde gas detection device. Background Art

[0002] A formaldehyde testing instrument is a device for detecting the concentration of formaldehyde gas in an environment. Since a formaldehyde testing instrument usually measures the formaldehyde concentration based on the working principle of a sensor, over time, the sensor may drift due to environmental factors, usage frequency, or other factors, resulting in a deviation between the output signal and the actual formaldehyde concentration. Therefore, the formaldehyde testing instrument needs to be calibrated regularly to ensure its detection accuracy. However, due to its characteristics of being easily adsorbed and unstable, formaldehyde is usually difficult to store. Therefore, the calibration of a formaldehyde testing instrument usually adopts on-site testing. However, in on-site testing, it is difficult to accurately know the real-time concentration of formaldehyde in the on-site environment. If the inaccurate real-time concentration of formaldehyde is compared with the formaldehyde concentration data measured by the formaldehyde testing instrument, the calibration of the formaldehyde testing instrument will be inaccurate. Content of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a formaldehyde gas detection device that can measure the real-time concentration of formaldehyde in the on-site environment and thus reliably calibrate the formaldehyde testing instrument.

[0004] To solve the above technical problem, the technical solution adopted by the utility model is: a formaldehyde gas detection device, including a formaldehyde testing instrument and a calibration device; the air outlet end of the formaldehyde testing instrument has a calibration port and an exhaust port, and a switching valve communicating with the calibration port and the exhaust port is arranged inside the formaldehyde testing instrument;

[0005] The calibration device includes a conversion chamber and a carbon dioxide detector for detecting the concentration of carbon dioxide generated in the conversion chamber. The inner cavity pipeline of the conversion chamber is connected to the calibration port, and catalytic plates are arranged at intervals along the gas flow direction in the inner cavity of the conversion chamber.

[0006] Further, the calibration device further includes an oxygen concentration detector and an oxygen cylinder. The detection end of the oxygen concentration detector is located in the inner cavity of the conversion chamber. A first electric control valve communicating with the oxygen concentration detector is arranged at the bottle mouth of the oxygen cylinder, and the oxygen cylinder is pipeline-connected to the inner cavity of the conversion chamber.

[0007] Further, a second electric control valve communicating with the oxygen concentration detector is arranged on the pipeline connecting the oxygen cylinder and the conversion chamber.

[0008] Further, the calibration device further includes a carbon dioxide detection chamber. The air outlet end of the conversion chamber is communicated with the inner cavity of the carbon dioxide detection chamber, and the detection end of the carbon dioxide detector is located in the carbon dioxide detection chamber.

[0009] Further, a water-absorbing cotton board is arranged in the pipeline connecting the conversion chamber and the carbon dioxide detection chamber.

[0010] The beneficial effects of the present utility model are as follows: The air outlet end of the formaldehyde testing instrument is divided into a calibration port and an exhaust port, and a switching valve is used to control the gas flow direction to the calibration port or the exhaust port. During normal formaldehyde concentration detection, the gas is discharged from the exhaust port of the formaldehyde testing instrument through the switching valve. When calibrating the formaldehyde testing instrument, the gas flows into the conversion chamber from the calibration port through the switching valve. In the conversion chamber, the catalytic plate reacts with oxygen and formaldehyde in the air to obtain water and carbon dioxide. Then, the carbon dioxide detector detects the carbon dioxide concentration. Next, the real-time formaldehyde concentration in the air is calculated according to the preset conversion rate. Finally, the formaldehyde concentration measured by the formaldehyde testing instrument itself is compared with the measured real-time formaldehyde concentration. If the formaldehyde concentration measured by the formaldehyde testing instrument is within 10% of the measured real-time formaldehyde concentration, there is no need to debug the formaldehyde testing instrument. If the formaldehyde concentration measured by the formaldehyde testing instrument is not within 10% of the measured real-time formaldehyde concentration, the formaldehyde testing instrument needs to be debugged. Description of the Drawings

[0011] Figure 1 is a system schematic diagram of a formaldehyde gas detection device proposed by the present utility model;

[0012] Figure 2 is a structural schematic diagram of a formaldehyde gas detection device proposed by the present utility model;

[0013] Label Description:

[0014] 1. Formaldehyde testing instrument; 11. Calibration port; 12. Exhaust port; 13. Switching valve;

[0015] 2. Calibration device; 21. Conversion chamber; 211. Catalytic plate; 22. Carbon dioxide detector; 23. Oxygen concentration detector; 24. Oxygen cylinder; 241. First electric control valve; 25. Carbon dioxide detection chamber;

[0016] 3. Second electric control valve; 4. Water-absorbing cotton board. Specific Embodiments

[0017] To describe the technical content, achieved objectives and effects of the present utility model in detail, the following is described in conjunction with the embodiments and with reference to the drawings.

[0018] Please refer to Figure 1 and Figure 2 As shown, a formaldehyde gas detection device of the present utility model includes a formaldehyde testing instrument 1 and a calibration device 2; the air outlet end of the formaldehyde testing instrument 1 has a calibration port 11 and an exhaust port 12, and a switching valve 13 communicating with the calibration port 11 and the exhaust port 12 is arranged in the formaldehyde testing instrument 1;

[0019] The calibration device 2 includes a conversion chamber 21 and a carbon dioxide detector 22 for detecting the concentration of carbon dioxide generated in the conversion chamber 21. The inner cavity pipeline of the conversion chamber 21 is connected to the calibration port 11, and catalytic plates 211 are arranged at intervals along the gas flow direction in the inner cavity of the conversion chamber 21.

[0020] Among them, the catalyst used on the catalytic plate 211 is preferably a copper-based catalyst or a platinum-based catalyst.

[0021] Working principle: During normal detection of the formaldehyde concentration, the exhaust port 12 is connected by the switching valve 13, and then the suction mechanism carried by the formaldehyde tester 1 itself sucks the air in the environment from the air inlet into the internal detection chamber for measuring the formaldehyde concentration, and finally discharges the air from the exhaust port 12 of the formaldehyde tester 1.

[0022] When calibrating the formaldehyde tester 1, the calibration port 11 is connected by the switching valve 13, and then the suction mechanism carried by the formaldehyde tester 1 itself sucks the air in the environment from the air inlet into the internal detection chamber for measuring the formaldehyde concentration. Then the air flows into the conversion chamber 21 from the calibration port 11. The catalytic plate 211 in the conversion chamber 21 reacts with the oxygen and formaldehyde in the air to obtain water and carbon dioxide. Then the carbon dioxide detector 22 detects the carbon dioxide concentration. Next, the real-time concentration of formaldehyde in the air is calculated according to the preset conversion rate. Finally, the real-time concentration of formaldehyde measured is compared with the formaldehyde concentration measured by the formaldehyde tester itself. If the formaldehyde concentration measured by the formaldehyde tester is within 10% of the measured real-time concentration of formaldehyde, there is no need to debug the formaldehyde tester. If the formaldehyde concentration measured by the formaldehyde tester is not within 10% of the measured real-time concentration of formaldehyde, the formaldehyde tester needs to be debugged.

[0023] Please refer to Figure 1 and Figure 2 As shown, further, the calibration device 2 further includes an oxygen concentration detector 23 and an oxygen cylinder 24. The detection end of the oxygen concentration detector 23 is located in the inner cavity of the conversion chamber 21. A first electric control valve 241 communicating with the oxygen concentration detector 23 is arranged at the bottle mouth of the oxygen cylinder 24, and the oxygen cylinder 24 is connected to the inner cavity of the conversion chamber 21 through a pipeline.

[0024] As can be seen from the above description, the oxygen concentration in the inner cavity of the conversion chamber 21 is measured by the oxygen concentration detector 23. If the oxygen concentration is insufficient, the first electric control valve 241 will be opened to allow the oxygen in the oxygen cylinder 24 to flow into the conversion chamber 21 to ensure that there is enough oxygen to react with formaldehyde.

[0025] Please refer to Figure 1As shown, further, a second electromagnetic control valve 3 communicating with an oxygen concentration detector 23 is provided on a pipeline connecting the oxygen cylinder 24 and the conversion chamber 21.

[0026] As can be seen from the above description, when oxygen does not need to be injected into the conversion chamber 21, the second electromagnetic control valve 3 will close to prevent formaldehyde from flowing into the pipeline connecting the oxygen cylinder 24 and the conversion chamber 21.

[0027] Please refer to Figure 1 As shown, further, the calibration device 2 further includes a carbon dioxide detection chamber 25. An air outlet end of the conversion chamber 21 communicates with an inner cavity of the carbon dioxide detection chamber 25, and a detection end of the carbon dioxide detector 22 is located in the carbon dioxide detection chamber 25.

[0028] As can be seen from the above description, after the conversion chamber 21 converts formaldehyde into water and carbon dioxide, the carbon dioxide enters the carbon dioxide detection chamber 25 through a pipeline to detect the carbon dioxide concentration, and the real-time concentration of formaldehyde in the air is calculated according to a preset conversion rate.

[0029] Please refer to Figure 1 As shown, further, a water absorption cotton board 4 is provided in a pipeline connecting the conversion chamber 21 and the carbon dioxide detection chamber 25.

[0030] As can be seen from the above description, before the carbon dioxide enters the carbon dioxide detection chamber 25, the water absorption cotton board 4 absorbs the moisture doped in the gas to further improve the detection accuracy.

[0031] Embodiment 1

[0032] A formaldehyde gas detection device, please refer to Figure 1 and Figure 2As shown in the figure, it includes a formaldehyde testing instrument 1 and a calibration device 2; the gas outlet end of the formaldehyde testing instrument 1 has a calibration port 11 and an exhaust port 12, and a switching valve 13 communicating with the calibration port 11 and the exhaust port 12 is arranged inside the formaldehyde testing instrument 1; the calibration device 2 includes a conversion chamber 21, a carbon dioxide detector 22, an oxygen concentration detector 23, an oxygen cylinder 24 and a carbon dioxide detection chamber 25. The inner cavity pipeline of the conversion chamber 21 is connected to the calibration port 11, and catalytic plates 211 are arranged at intervals along the gas flow direction in the inner cavity of the conversion chamber 21. The detection end of the oxygen concentration detector 23 is located in the inner cavity of the conversion chamber 21. A first electric control valve 241 communicating with the oxygen concentration detector 23 is arranged at the bottle mouth of the oxygen cylinder 24, and the oxygen cylinder 24 is pipeline-connected to the inner cavity of the conversion chamber 21. A second electric control valve 3 communicating with the oxygen concentration detector 23 is arranged on the pipeline connecting the oxygen cylinder 24 and the conversion chamber 21. The gas outlet end of the conversion chamber 21 is communicated with the inner cavity of the carbon dioxide detection chamber 25, and the detection end of the carbon dioxide detector 22 is located in the carbon dioxide detection chamber 25. A water absorption cotton board 4 is arranged in the pipeline connecting the conversion chamber 21 and the carbon dioxide detection chamber 25.

[0033] Working principle: During normal formaldehyde concentration detection, the switching valve 13 connects the exhaust port 12, and then the air suction mechanism carried by the formaldehyde testing instrument 1 sucks the air in the environment from the air inlet into the internal detection cavity for formaldehyde concentration measurement, and finally discharges the air from the exhaust port 12 out of the formaldehyde testing instrument 1.

[0034] When calibrating the formaldehyde testing instrument 1, the switching valve 13 connects the calibration port 11, and then the air suction mechanism carried by the formaldehyde testing instrument 1 sucks the air in the environment from the air inlet into the internal detection cavity for formaldehyde concentration measurement. Then the air flows into the conversion chamber 21 from the calibration port 11, and the catalytic plates 211 in the conversion chamber 21 react with the oxygen and formaldehyde in the air to obtain water and carbon dioxide. During the conversion process, if the oxygen concentration detector 23 measures that the oxygen concentration in the inner cavity of the conversion chamber 21 is insufficient, the first electric control valve 241 and the second electric control valve 3 will be opened to allow the oxygen in the oxygen cylinder 24 to flow into the conversion chamber 21 to ensure that there is enough oxygen to react with formaldehyde. Then the carbon dioxide flows through the water absorption cotton board 4 into the carbon dioxide detection chamber 25, and the carbon dioxide detector 22 detects the carbon dioxide concentration. The real-time formaldehyde concentration in the air is calculated according to the preset conversion rate. Finally, the formaldehyde concentration measured by the formaldehyde testing instrument is compared with the real-time formaldehyde concentration measured. If the formaldehyde concentration measured by the formaldehyde testing instrument is within 10% of the measured real-time formaldehyde concentration, there is no need to debug the formaldehyde testing instrument. If the formaldehyde concentration measured by the formaldehyde testing instrument is not within 10% of the measured real-time formaldehyde concentration, the formaldehyde testing instrument needs to be debugged.

[0035] The above are only embodiments of the present utility model, and thus do not limit the patent scope of the present utility model. Any equivalent transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in the relevant technical fields, shall similarly be included within the patent protection scope of the present utility model.

Claims

1. A formaldehyde gas detection device, characterized in that: It comprises a formaldehyde testing instrument and a calibration device; the gas outlet end of the formaldehyde testing instrument has a calibration port and an exhaust port, and the formaldehyde testing instrument is provided with a switching valve connected with the calibration port and the exhaust port; The calibration device comprises a conversion chamber and a carbon dioxide detector for detecting the concentration of carbon dioxide generated in the conversion chamber. The inner cavity pipeline of the conversion chamber is connected to the calibration port, and the inner cavity of the conversion chamber is provided with catalytic plates arranged at intervals along the gas flow direction.

2. The formaldehyde gas detection device according to claim 1, characterized in that: The calibration device also includes an oxygen concentration detector and an oxygen cylinder. The detection end of the oxygen concentration detector is located in the inner cavity of the conversion chamber. The mouth of the oxygen cylinder is provided with a first electrically controlled valve that is communicatively connected to the oxygen concentration detector. The oxygen cylinder pipeline is connected to the inner cavity of the conversion chamber.

3. The formaldehyde gas detection device according to claim 2, characterized in that: A second electric-controlled valve in communication with the oxygen concentration detector is arranged on the pipeline connecting the oxygen cylinder and the conversion chamber.

4. The formaldehyde gas detection device according to claim 1, characterized in that: The calibration device also includes a carbon dioxide detection chamber, the gas outlet end of the conversion chamber is connected to the inner cavity of the carbon dioxide detection chamber, and the detection end of the carbon dioxide detector is located in the carbon dioxide detection chamber.

5. The formaldehyde gas detection device according to claim 4, characterized in that: A water-absorbing cotton board is arranged in the pipeline connecting the conversion chamber and the carbon dioxide detection chamber.

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