A tail gas absorption treatment device for ion mobility spectrometry

Abstract

The present invention discloses a tail gas absorption treatment device for ion mobility spectrometry. The device is externally composed of an upper and lower structure, wherein the upper structure comprises a gas purification pipe, and the lower structure comprises a cubic chamber and an air pump assembly for discharging gas from the treatment device. The remaining other space inside the tail gas absorption treatment device is a buffer storage chamber for purified gas. The tail gas absorption treatment device can purify the tail gas source of the ion mobility spectrometer. The entire device is sealed under the condition that multiple ion mobility spectrometers are used simultaneously and will not generate outlet resistance for the ion mobility spectrometers.

Description

Technical Field

[0001] The invention belongs to the technical field of ion mobility spectrometry, and in particular relates to a tail gas absorption treatment device for ion mobility spectrometry. Background Art

[0002] Ion Mobility Spectrometry (IMS) is a separation and detection technology that appeared in the 1970s. Compared with traditional mass spectrometry and chromatography instruments, it has the characteristics of simple structure, high sensitivity, fast analysis speed, and reliable results. It can detect trace substances in the atmospheric environment and is suitable for on-site use. Its working condition is to perform analysis and detection under normal pressure.

[0003] The ionization source is a key component in the ion mobility spectrometer, and plays an important role in the ionization and separation of sample molecules. Common ionization sources include radioactive ionization sources, photoionization sources, corona discharge ionization sources, electrospray ionization sources, etc. In recent years, the latest progress in the application of mobility spectrometry is to add chemical dopants during use, which can not only optimize the performance of the instrument, but also enable some undetectable substances to be ionized, separated and analyzed in the detector of the ion mobility spectrometer. Common chemical dopants include acetone, butanone, anisole, nicotinamide, etc. Chemical dopants are often added to the carrier gas and float gas of the mobility spectrometer during use, and finally flow out from the tail gas pipe of the mobility spectrometer. If the tail gas is discharged directly into the air, it will definitely cause certain pollution to the air.

[0004] Thermal desorption injectors commonly used in ion mobility spectrometry often dissolve solid and liquid samples in organic solvents for injection analysis. After thermal desorption, the organic solvent is mixed with the carrier gas and enters the ion mobility tube, and finally flows out from the tail gas pipe of the mobility spectrometer. Direct discharge into the air will also cause certain air pollution.

[0005] Since 1974, China has implemented the "Trial Standards for Industrial "Three Wastes" Emissions", which stipulates the emission standards for 13 harmful substances such as sulfur dioxide, carbon monoxide, and hydrogen sulfide. The atmospheric pollutant emission standards are designed to control the emission of pollutants and make the air quality meet the environmental quality standards. They set the limit standards for the amount or concentration of pollutants discharged into the atmosphere. They are approved and promulgated by relevant departments and are legally binding. The whole society attaches great importance to the emission of atmospheric pollution. Summary of the invention

[0006] Based on the above background technology, on one hand, the present invention provides a gas purification tube, which is a cylindrical hollow metal tube; a solid metal rod is fixed in the hollow metal tube along the axial direction; an annular groove is provided on the surface of the metal rod; a gas transmission pipeline is wrapped around the annular groove; a through hole is provided on the surface of the gas transmission pipeline; and an organic adsorbent is filled in the hollow metal tube.

[0007] Based on the above technical solution, preferably, the ratio of the outer diameter of the metal rod to the inner diameter of the metal tube is 1:2 to 1:4.

[0008] Based on the above technical solution, preferably, the through-porosity of the surface of the gas transmission tube is 40%-60%.

[0009] In another aspect, the present invention provides a tail gas absorption treatment device for ion mobility spectrometry, the tail gas absorption treatment device includes the above-mentioned gas purification pipe; the tail gas absorption treatment device is composed of a cavity I and a cavity II which are arranged in a sealed manner; the bottom end of the cavity I is open; the top end of the cavity II is open; the cavity I and the cavity II are sealed by an "O" ring; the gas purification pipe is fixed in the cavity I; the cavity II is provided with a cubic chamber and an exhaust pump assembly for exhausting gas from the treatment device; the upper surface of the cubic chamber is provided with a through hole; the cubic chamber It is filled with organic adsorbent; the remaining space inside the exhaust gas absorption treatment device except the gas purification pipe, the cubic chamber and the vacuum pump assembly is a buffer storage chamber for the purified gas; the ion mobility spectrometer exhaust gas outlet pipe is connected with the gas purification pipe via a connecting pipeline, and the gas purification pipe and the cubic chamber are connected via a connecting pipeline; the exhaust gas from the ion mobility spectrometer exhaust gas outlet pipe enters the gas purification pipe and the cubic chamber in turn via the connecting pipeline, and the exhaust gas entering the cubic chamber enters the buffer storage chamber through the through hole on the upper surface of the cubic chamber after being treated, and the purified gas is discharged by the vacuum pump assembly.

[0010] Based on the above technical solution, preferably, the cross-section of the cavity wall where cavity I and cavity II are connected is a sloped cross-section and is inclined toward the cavity, which is conducive to the diffusion of gas and can avoid the backflow of gas. An annular groove is provided on the cavity wall at the connection point for fixing the "O" ring.

[0011] Based on the above technical solution, preferably, the gas purification pipe is fixed to the top plate of the cavity I through a bracket and a shock-absorbing silicone pad.

[0012] Based on the above technical solution, preferably, the organic adsorbent includes activated carbon and molecular sieve; the ratio of the activated carbon to the molecular sieve is 1:1 to 4:1.

[0013] Based on the above technical solution, preferably, the through-hole rate of the upper surface of the cubic cavity is 20%-50%.

[0014] Based on the above technical solution, preferably, the suction flow rate of the suction pump in the suction pump assembly is 5-10 L / min.

[0015] Based on the above technical solution, preferably, the through holes opened on the side of the cavity I are used for the exhaust gas of the ion mobility spectrometer exhaust outlet pipe to enter; the number of the through holes can be changed according to the number of mobility spectrometer instruments, and the unused through holes are sealed by plugs. In addition to adapting to the change in the number of ion mobility spectrometers by opening different numbers of through holes on the side of the cavity I, the flow rate of the vacuum pump can also be changed by adjusting or replacing the vacuum pump.

[0016] The tail gas terminal pipe of the ion mobility spectrometer is connected to the tail gas absorption treatment device of the present invention, which does not leak and can ensure that the tail gas flows without resistance.

[0017] Beneficial Effects

[0018] (1) The tail gas of the ion mobility spectrometer is purified twice, wherein the gas transmission pipeline is spirally wound inside the gas purification tube to make the solvent in the tail gas fully contact with the purifier, thereby improving the treatment effect.

[0019] (2) The tail gas absorption treatment device in the present invention is sealed and pressure-resistant, and the vacuum pump can quickly discharge the purified tail gas out of the device to avoid pressure generated at the terminal, which affects the detection and analysis of the ion mobility spectrum.

[0020] (3) The tail gas absorption treatment device in the present invention has a simple structure, is easy to use, and is easy to manufacture, and can be applied online at any site. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following is further described in detail with reference to the accompanying drawings.

[0022] Figure 1 It is a schematic diagram of the appearance structure and internal layout of the tail gas absorption treatment device;

[0023] Figure 2 This is a schematic diagram of the tail gas flow direction of the tail gas absorption treatment device;

[0024] Among them: 1 is cavity I, 2 is the cubic chamber area in cavity II, 3 is the vacuum pump assembly area of ​​cavity II, 4 is the two-way quick connector I-1, 5 is the four-turn quick connector II, 6 is the gas purification tube, 7 is the cubic chamber, 8 is the vacuum pump assembly, 9 is the fixed two-way quick connector I-5, 10 is the quick connector III-1, 11 is the quick connector III-2, 12 is the quick connector III-3, 13 is the quick connector III-4, and 14 is the quick connector III-5. DETAILED DESCRIPTION

[0025] A tail gas absorption treatment device for ion mobility spectrometry, the device is composed of an upper cavity I and a lower cavity II which are sealed, the upper cavity I is fixed with a gas purification tube, the lower cavity II is fixed with a cubic chamber and an air pump assembly, the tail gas enters the gas purification tube, the cubic chamber, and the buffer storage chamber in sequence, and the air pump assembly discharges the purified gas; the cavity walls of the upper and lower cavities of the tail gas absorption treatment device at the connection point are inclined toward the cavity, and an annular groove is provided on the cavity wall at the connection point, and an "O" ring is fixed in the groove for sealing cavity I and cavity II.

[0026] Four through holes are opened on the side of the upper cavity I of the tail gas absorption treatment device, which are respectively fixed with two-way quick connectors I-1, I-2, I-3 and I-4. The tail gas outlet pipes of the four ion migration spectrometers are respectively connected to one end of the two-way quick connectors I-1, I-2, I-3 and I-4; the other ends of the two-way quick connectors I-1, I-2, I-3 and I-4 are respectively connected to one end of the four-turn quick connector II, and the other end of the four-turn quick connector II is connected to the inlet pipe end of the gas purification pipe; the two-way quick connector I-1 and the four-turn quick connector II, the quick connector II and the inlet pipe end of the gas purification pipe are connected through a polytetrafluoroethylene tube; the gas purification pipe is a cylindrical, hollow, closed metal pipe structure, which is transversely fixed in the upper cavity I of the tail gas absorption treatment device, and the cylindrical closed The left and right end faces of the closed structure are respectively fixed with quick connectors III-1 and III-2 with threaded holes at one end; the quick connector III-1 with a threaded hole at one end fixed on the left end face is the inlet pipe end of the gas purification pipe, and the quick connector III-2 with a threaded hole at one end fixed on the right end face is the outlet pipe end of the gas purification pipe; the inner space of the metal pipe has a solid metal rod with a diameter of 1 cm along the axis direction; the surface of the solid metal rod has an annular groove, and the gas transmission pipeline is spirally wound in the annular groove; the spirally wound gas transmission pipe is a polytetrafluoroethylene pipe, and the surface of the gas transmission pipe has through holes; the metal pipe is filled with organic adsorbent; the exhaust gas is fully contacted with the organic adsorbent through the spirally wound gas transmission pipe for the first absorption treatment. Quick connectors III-4 and III-5 are respectively fixed at both ends of the inner cavity of the metal pipe; the quick connector III-4 in the metal pipe is connected to the quick connector III-1 through a through hole; the quick connector III-5 in the metal pipe is connected to the quick connector III-2 through a through hole.

[0027] A cubic chamber is fixed in cavity II; a through hole is arranged on the upper surface of the cubic chamber; the cubic chamber is filled with an organic adsorbent, and a quick connector III-3 with a threaded hole is fixed near the bottom of the cubic chamber; the quick connector III-2 is connected to the quick connector III-3 through a polytetrafluoroethylene tube, so that the exhaust gas treated by the gas purification tube passes into the cubic chamber; after secondary absorption treatment by the organic adsorbent in the cubic chamber, the exhaust gas overflows through the upper surface and enters the buffer storage chamber, and then the purified gas is discharged by the vacuum pump assembly.

[0028] According to the exhaust gas flow direction, the end of the ion mobility spectrometer exhaust gas outlet pipe is connected in sequence through a fixed two-way quick connector I-1 (4), a four-to-one quick connector II (5), a quick connector III-1 (10), a quick connector III-4 (13), a gas purification tube (6), a quick connector III-5 (14), a quick connector III-2 (11), a quick connector III-3 (12), a cubic chamber (7), an exhaust pump assembly (8), and a fixed two-way quick connector I-5 (9). Finally, the purified gas is discharged into the air through the quick connector I-5 (9).

[0029] Example 1

[0030] The tail gas absorption treatment device of the present invention is subjected to a pressure test, wherein the quick connector I-5 (9) connected to the tail gas outlet end is connected to one end of a polytetrafluoroethylene tube, and the other end of the polytetrafluoroethylene tube is connected to a pressure gauge, so that the pressure of the gas entering the chamber is regulated by the pressure gauge at 0.5 MPa; the tail gas absorption treatment device can withstand pressure and does not leak during normal use.

[0031] Example 2

[0032] A sealing test was performed on the exhaust gas absorption treatment device in the present invention. The exhaust gases of four ion mobility spectrometers were connected to allow them to enter the exhaust gas absorption treatment device. The quick connector I-5 (9) connected to the exhaust gas outlet was connected to a polytetrafluoroethylene tube. The gas output was controlled at 2L / min by connecting a mass flow meter. In this state, the exhaust gas absorption treatment device did not leak, and the gas connection system of the four ion mobility spectrometers could ensure normal operation under normal pressure conditions.

[0033] The sealing adapter assembly in the present invention is not limited to the above-mentioned embodiments. The improvements and modifications made to the present invention by those skilled in the art based on the disclosure of the present invention are all within the protection scope of the patent of the present invention.

Claims

1. A tail gas absorption treatment device for ion mobility spectrometry, characterized in that: The tail gas absorption treatment device comprises a gas purification pipe; the tail gas absorption treatment device is composed of a cavity I and a cavity II which are arranged in a sealed manner from top to bottom; the bottom end of the cavity I is open; the top end of the cavity II is open; the cavity I and the cavity II are assembled by an "O" ring seal; the gas purification pipe is fixed in the cavity I; a cubic chamber and an air pump assembly for discharging gas out of the treatment device are arranged in the cavity II; a through hole is arranged on the upper surface of the cubic chamber; the cubic chamber is filled with an organic adsorbent; the ion mobility spectrometer tail gas outlet pipe is connected to the gas purification pipe through a pipeline, and the gas purification pipe and the cubic chamber are connected through a pipeline; the tail gas of the ion mobility spectrometer tail gas outlet pipe enters the gas purification pipe and the cubic chamber in turn through the pipeline; The gas purification tube is a cylindrical hollow metal tube; a solid metal rod is fixed in the hollow metal tube along the axis direction; a ring groove is provided on the surface of the metal rod; a gas transmission pipeline is wound around the ring groove; a through hole is provided on the surface of the gas transmission pipeline; an organic adsorbent is filled in the hollow metal tube; The through-hole rate of the upper surface of the cubic chamber is 20%-50%; The through-hole rate of the surface of the gas transmission tube is 40%-60%; The organic adsorbent comprises activated carbon and molecular sieve, and the ratio of the activated carbon to the molecular sieve is 1:1 to 4:

1.

2. The tail gas absorption treatment device for ion mobility spectrometry according to claim 1, characterized in that: The ratio of the outer diameter of the metal rod to the inner diameter of the metal tube is 1:2 to 1:

4.

3. The tail gas absorption treatment device for ion mobility spectrometry according to claim 1, characterized in that: The cross section of the cavity wall where the cavity I and cavity II are connected is a sloped cross section and is inclined toward the cavity. An annular groove is provided on the cavity wall at the connection point for fixing the "O" ring.

4. The tail gas absorption treatment device for ion mobility spectrometry according to claim 1, characterized in that: The gas purification pipe is fixed to the top plate of the cavity I through a bracket and a shock-absorbing silicone pad.

5. The tail gas absorption treatment device for ion mobility spectrometry according to claim 1, characterized in that: The flow rate of the vacuum pump is 5-10 L / min.

6. The tail gas absorption treatment device for ion mobility spectrometry according to claim 1, characterized in that: The through holes opened on the side of the cavity I are used for the exhaust gas from the exhaust outlet pipe of the ion mobility spectrometer to enter; the number of the through holes can be changed according to the number of mobility spectrometer instruments, and the unused through holes are sealed by plugs.

Images