A thermal analyzer with low temperature adsorption function

Abstract

The present invention discloses a thermal analyzer with low-temperature adsorption function, including an axial flow fan, a radiator, a heat preservation box, a refrigeration sheet, a cold storage sheet, a six-way valve, a driving motor, a carrier gas flow controller, a secondary adsorption tube, a primary adsorption tube, a primary heating body, a purge gas flow controller, a vent pipe, a detection device and a heating wire. The axial flow fan is provided with a radiator, and the axial flow fan is provided with a heat preservation box. The heat preservation box is provided with a refrigeration sheet and a cold storage sheet, and the cold storage sheet is provided on the refrigeration sheet. A thermal analyzer with low-temperature adsorption function is manufactured by adopting the above technical scheme. The secondary thermal analysis technology is adopted to make the peak shape sharper and improve the detection limit. Since the secondary analysis device has the advantages of small size, low-temperature concentration and rapid heating, the system error is reduced, the unit concentration is increased, and the detection limit is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of gas collection, and in particular to a thermal analyzer with a low-temperature adsorption function. Background Art

[0002] With the improvement of living standards, air pollution problems are becoming more and more common, which has attracted widespread attention from residents and scholars. The quality of air has a direct impact on people's health. There are many types of air pollutants, among which formaldehyde and total volatile compounds (TVOC) are the most important typical pollutants, with the characteristics of wide pollution sources, large concentration range and long release period. Formaldehyde has strong stimulation and allergic reactions to people's vision, smell and respiratory organs, and has potential carcinogenicity. It is relatively harmful to people's health, especially benzene series. There are many types of TVOC and complex components. Long-term inhalation of TVOC can cause immune disorders in the body, and in severe cases, it can damage the liver and hematopoietic system. The country has successively issued several standards such as GB50325-2010 and GBZ / T300.66-2017 to make clear provisions on detection methods and limit standards. The detection limit of trace components is limited by the sensitivity of the analytical instrument, so the sample is often collected for analysis by concentration. First, a certain amount of sample gas is adsorbed by an adsorption tube, and then the captured volatile organic compounds are released from the adsorbent by thermal analysis.

[0003] Therefore, a thermal analyzer with low-temperature adsorption function is needed. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a thermal analyzer with low-temperature adsorption function.

[0005] A thermal analyzer with low-temperature adsorption function in the present invention comprises an axial flow fan, a radiator, a heat preservation box, a refrigeration sheet, a cold storage sheet, a six-way valve, a driving motor, a carrier gas flow controller, a secondary adsorption tube, a primary adsorption tube, a primary heating body, a purge gas flow controller, a venting pipe, a detection device and a heating wire, wherein the axial flow fan is provided with a radiator, the axial flow fan is provided with a heat preservation box, the heat preservation box is provided with a refrigeration sheet and a cold storage sheet, the cold storage sheet is provided on the refrigeration sheet,

[0006] The six-way valve is connected to the driving motor, and the six-way valve includes a first valve, a second valve, a third valve, a fourth valve, a fifth valve and a sixth valve. The first valve is connected to the carrier gas flow controller, the second valve is connected to the secondary adsorption tube, the secondary adsorption tube is connected to the insulation box, the third valve is connected to the first-level adsorption tube, the first-level adsorption tube is arranged on the first-level heating body, the first-level adsorption tube is connected to the purge gas flow controller, the fourth valve is connected to the vent pipe, the fifth valve is connected to the second-level adsorption tube, the second-level adsorption tube is connected to the insulation box, the sixth valve is connected to the detection equipment, and the second-level adsorption tube is provided with a heating wire.

[0007] In the above solution, when the six-way valve is in the primary analysis stage, the first valve is connected to the sixth valve, the second valve is connected to the third valve, and the fourth valve is connected to the fifth valve.

[0008] In the above solution, when the six-way valve is in the secondary analysis stage, the first valve is connected to the second valve, the third valve is connected to the fourth valve, and the fifth valve is connected to the sixth valve.

[0009] In the above solution, a transparent window is provided on the heat preservation box.

[0010] In the above solution, a sealing nut is provided on the secondary adsorption tube.

[0011] In the above solution, the second valve is connected to the secondary adsorption tube through an inert pipeline, and the fifth valve is connected to the secondary adsorption tube through an inert pipeline.

[0012] In the above scheme, the purge gas flow controller is connected to nitrogen to control the flow of nitrogen.

[0013] In the above scheme, a variable diameter structure is arranged inside the secondary adsorption tube, an adsorption material is arranged inside the variable diameter structure, and fixing objects are arranged before and after the adsorption material.

[0014] The advantages and beneficial effects of the present invention are as follows: the present invention provides a thermal analyzer with low-temperature adsorption function. The secondary thermal analysis technology is used to make the peak shape sharper and improve the detection limit. The so-called secondary thermal analysis technology is to conduct a second low-temperature adsorption concentration on the organic matter released by the first heating on the basis of the first analysis, that is, cold capture, and then instantaneously heat it for the second time to enter the chromatograph of the detection device. Since the secondary analysis device has the advantages of small size, low-temperature concentration, and rapid heating, the system error is reduced, the unit concentration is increased, and the detection limit is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative labor.

[0016] Figure 1 It is a structural schematic diagram of the present invention;

[0017] Figure 2 It is a structural diagram of the first-level parsing process;

[0018] Figure 3 It is a structural diagram of the secondary analysis process;

[0019] Figure 4 Schematic diagram of the structure of the secondary adsorption tube.

[0020] In the figure: 1, axial flow fan 2, radiator 3, insulation box 4, refrigeration plate 5, cold storage plate 6, six-way valve 7, drive motor 8, carrier gas flow controller 9, secondary adsorption tube 10, primary adsorption tube 11, primary heating body 12, purge gas flow controller 13, vent pipe 14, detection equipment 15, heating wire 16, transparent window 17, sealing nut 18, inert pipeline 61, first valve 62, second valve 63, third valve 64, fourth valve 65, fifth valve 66, sixth valve 91, diameter structure 92, adsorption material 93, fixed object DETAILED DESCRIPTION

[0021] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0022] like Figure 1 As shown, the present invention is a thermal analyzer with low-temperature adsorption function, including an axial flow fan 1, a radiator 2, a heat preservation box 3, a refrigeration sheet 4, a cold storage sheet 5, a six-way valve 6, a driving motor 7, a carrier gas flow controller 8, a secondary adsorption tube 9, a primary adsorption tube 10, a primary heating body 11, a purge gas flow controller 12, a venting pipe 13, a detection device 14 and a heating wire 15. The axial flow fan 1 is provided with a radiator 2, the axial flow fan 1 is provided with a heat preservation box 3, the heat preservation box 3 is provided with a refrigeration sheet 4 and a cold storage sheet 5, and the cold storage sheet 5 is provided on the refrigeration sheet 4.

[0023] The six-way valve 6 is connected to the driving motor 7, and the six-way valve 6 includes a first valve 61, a second valve 62, a third valve 63, a fourth valve 64, a fifth valve 65 and a sixth valve 66. The first valve 61 is connected to the carrier gas flow controller 8, the second valve 62 is connected to the secondary adsorption tube 9, the secondary adsorption tube 9 is connected to the insulation box 3, the third valve 63 is connected to the primary adsorption tube 10, the primary adsorption tube 10 is arranged on the primary heating body 11, the primary adsorption tube 10 is connected to the purge gas flow controller 12, the fourth valve 64 is connected to the vent pipe 13, the fifth valve 65 is connected to the secondary adsorption tube 9, the secondary adsorption tube 9 is connected to the insulation box 3, the sixth valve 66 is connected to the detection equipment 14, and the secondary adsorption tube 9 is provided with a heating wire 15.

[0024] like Figure 2 As shown, when the six-way valve 6 is in the primary analysis stage, the first valve 61 is connected to the sixth valve 66 , the second valve 62 is connected to the third valve 63 , and the fourth valve 64 is connected to the fifth valve 65 .

[0025] like Figure 3 As shown, when the six-way valve 6 is in the secondary analysis stage, the first valve 61 is connected to the second valve 62 , the third valve 63 is connected to the fourth valve 64 , and the fifth valve 65 is connected to the sixth valve 66 .

[0026] The heat preservation box 3 is provided with a transparent window 16. The secondary adsorption tube 9 is provided with a sealing nut 17. The second valve 62 is connected to the secondary adsorption tube 9 through an inert pipeline 18, and the fifth valve 65 is connected to the secondary adsorption tube 9 through an inert pipeline 18.

[0027] The purge gas flow controller 12 is connected to nitrogen to control the flow of nitrogen. Figure 4 As shown, a variable diameter structure 91 is provided inside the secondary adsorption tube 9 , an adsorption material 92 is provided inside the variable diameter structure 91 , and fixing objects 93 are provided before and after the adsorption material 92 .

[0028] Preparation stage: The primary heating body is heated to 200-300℃, and the driving motor drives the six-way valve to rotate until the first valve conducts to the sixth valve, the second valve conducts to the third valve, and the fourth valve conducts to the fifth valve. The refrigeration plate works to reduce the temperature of the cold storage plate to 5--30℃ (set according to the requirements of the test components), and the carrier gas flow controller adjusts a certain flow of nitrogen through the gas pipeline through the first valve-sixth valve port of the six-way valve and the transmission pipeline with a certain temperature to connect to the chromatograph of the detection equipment.

[0029] Primary analysis stage: connect the primary adsorption tube with volatile organic compounds and put it into the primary heating body for heating. Turn on the purge gas flow controller and introduce nitrogen at a flow rate of about 50-100mL / min to heat and analyze the components adsorbed in the primary adsorption tube. Generally, continuous purge is required for 5-10 minutes. Under the nitrogen, the gas passes through the third valve-second valve port of the six-way valve through the pipeline into the secondary adsorption tube in a low-temperature environment. The gas analyzed from the primary adsorption tube is adsorbed by the adsorbent in the secondary adsorption tube. Inorganic gases and non-adsorbed components flow out from the fifth valve-fourth valve of the six-way valve and are vented from the gas line.

[0030] Secondary analysis stage: The driving motor drives the six-way valve to rotate to the position where the first valve conducts to the second valve, the third valve conducts to the fourth valve, and the fifth valve conducts to the sixth valve. The heating wire wrapped around the secondary adsorption tube is heated to quickly heat the temperature of the secondary adsorption tube to 200-300°C within 5-60 seconds. The nitrogen from the carrier gas flow controller flows into the secondary adsorption tube through the gas pipeline through the first valve-second valve port of the six-way valve, and carries the analyzed volatile organic matter out of the fifth valve-sixth valve port of the six-way valve, and enters the chromatograph of the detection equipment through a transmission pipeline with a certain temperature for detection.

[0031] The secondary adsorption tube can be used repeatedly, which reduces the cost of use. Compared with the primary adsorption tube, the secondary adsorption tube has the advantages of small size, rapid heating, short analysis time, low temperature concentration, reduced system error, and increased unit concentration greatly improves the detection limit.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal analyzer with low temperature adsorption function, characterized in that: The invention comprises an axial flow fan, a radiator, a heat preservation box, a refrigeration sheet, a cold storage sheet, a six-way valve, a driving motor, a carrier gas flow controller, a secondary adsorption tube, a primary adsorption tube, a primary heating body, a purge gas flow controller, a venting pipe, a detection device and a heating wire. The axial flow fan is provided with a radiator, the axial flow fan is provided with a heat preservation box, the heat preservation box is provided with a refrigeration sheet and a cold storage sheet, the cold storage sheet is provided on the refrigeration sheet, the secondary adsorption tube is provided with a sealing nut, The six-way valve is connected to the driving motor, and the six-way valve includes a first valve, a second valve, a third valve, a fourth valve, a fifth valve and a sixth valve. The first valve is connected to a carrier gas flow controller, the second valve is connected to a secondary adsorption tube, the secondary adsorption tube is connected to an insulation box, the third valve is connected to a primary adsorption tube, the primary adsorption tube is arranged on a primary heating body, the primary adsorption tube is connected to a purge gas flow controller, the fourth valve is connected to a vent pipe, the fifth valve is connected to a secondary adsorption tube, the secondary adsorption tube is connected to an insulation box, the sixth valve is connected to a detection device, a heating wire is arranged on the secondary adsorption tube, the second valve is connected to the secondary adsorption tube through an inert pipeline, and the fifth valve is connected to the secondary adsorption tube through an inert pipeline; When the six-way valve is in the primary analysis stage, the first valve is connected to the sixth valve, the second valve is connected to the third valve, and the fourth valve is connected to the fifth valve. When the six-way valve is in the secondary analysis stage, the first valve is connected to the second valve, the third valve is connected to the fourth valve, and the fifth valve is connected to the sixth valve.

2. A thermal analyzer with low temperature adsorption function according to claim 1, characterized in that: The heat preservation box is provided with a transparent window.

3. A thermal analyzer with low temperature adsorption function according to claim 1, characterized in that: The purge gas flow controller is connected to nitrogen to control the flow of nitrogen.

4. A thermal analyzer with low temperature adsorption function according to claim 1, characterized in that: A variable diameter structure is arranged inside the secondary adsorption tube, an adsorption material is arranged inside the variable diameter structure, and fixing objects are arranged before and after the adsorption material.

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