CN117491115A - An online condensation water removal device and method suitable for mass spectrometers - Google Patents

Abstract

An online condensing water removal device and method suitable for mass spectrometers, wherein the mass spectrometer and the sampling device are connected through a gas pipeline, and the gas pipeline serves as a channel for the sample to be measured: online condensation water removal device It includes a sampling valve, a three-way valve, a refrigerator, a heating plate and an air extraction pump. The sampling valve is arranged on the gas pipeline near the side of the sampling device; the three-way valve is arranged on the side near the mass spectrometer. On the gas pipeline, it is connected to the air extraction pump at the same time; the refrigerator is connected to the gas pipeline between the sampling valve and the three-way valve through an insulated pipe; the outside of the insulated pipe is sleeved with A heat-conducting tube and an insulated tube; a heating sheet is arranged on the gas pipeline between the insulated tube and the three-way valve; and the air inlet of the air extraction pump is connected to the three-way valve. The invention has good air tightness and efficient thermal conductivity, can shorten the preheating time, reduce water removal power consumption, has a simple structure, is easy to build, does not use consumables, and can be recycled.

Description

An online condensation water removal device and method suitable for mass spectrometers

Technical field

The invention relates to an online water removal device suitable for mass spectrometers, in particular to an online condensation water removal device and method suitable for mass spectrometers, and belongs to the technical field of gaseous sample analysis.

Background technique

Mass spectrometry is an analytical technology that works under vacuum conditions and achieves ion separation and detection based on the difference in charge-to-mass ratio of substances. It has been widely used in fields such as food safety, environmental protection, and medical health. The analytical performance of the mass spectrometer will be interfered by water vapor. On the one hand, the presence of water vapor will reduce the service life of the equipment. On the other hand, it will interfere with the detection spectrum, thus affecting the qualitative and quantitative detection results. This limits the application of mass spectrometry in the field of on-site detection to a certain extent. Therefore, pre-treatment of water vapor removal is extremely important for the use of mass spectrometers in on-site environments.

Current gas water removal methods include liquid nitrogen water removal, adsorbent material water removal, water vapor exchange membrane-based water removal methods, and water removal methods based on condensation technology. Among them, the liquid nitrogen dewatering method requires the consumption of a large amount of liquid nitrogen, and long-term work requires manual replenishment of liquid nitrogen. It has safety risks and is not suitable for long-term use in the on-site environment. The adsorbent material needs to be replaced regularly to remove water. At the same time, the adsorbent material may introduce particulate impurities, destroy the vacuum environment, and cause damage to the mass spectrometer. The water removal method based on interactive membranes relies on dry purge gas, has poor air tightness, and is incompatible with the high vacuum analysis environment of mass spectrometers. The water removal method based on condensation technology has the advantages of adjustable temperature, small size, low power consumption, no need to replace consumables, and continuous long-term use, and can achieve efficient, clean, and continuous water removal needs.

Among the existing water removal methods based on condensation technology, an online trace gas condensation water removal device and method with the publication number CN115430264A is known. Although it can realize the integration of water removal and detection of the detector, it still has the following shortcomings:

1) The refrigeration component of the condensation and water removal device is connected to the shell, which makes the heat transfer area too large, resulting in high cooling power consumption, long preheating time, and limited condensation effect.

2) This device relies on gravity to export condensed water. When used in ultra-low pressure scenarios, the condensed water will quickly vaporize, which will greatly increase the water vapor content in the sample.

3) The design structure of the circulating condensation chamber in this device is complex, the processing is difficult, and the air tightness cannot be guaranteed, which makes the device unsuitable for water removal in mass spectrometers.

Contents of the invention

In order to overcome the above-mentioned shortcomings of related technologies, the present invention provides an online condensation water removal device and method suitable for mass spectrometers, which has good air tightness and efficient thermal conductivity, can shorten the preheating time, and reduce the power consumption of water removal. , simple structure, easy to build, no consumables used, and can be recycled.

A technical solution adopted by the present invention to solve its technical problems is:

An online condensing water removal device suitable for a mass spectrometer, the mass spectrometer and the sampling device are connected through a gas pipeline, and the gas pipeline serves as a channel for the sample to be measured; the online condensation water removal device includes:

A sampling valve, which is arranged on the gas pipeline close to the side of the sampling device and is used to control the on-off of sampling;

A three-way valve, the three-way valve is arranged on the gas pipeline close to the side of the mass spectrometer, and is connected to the air pump at the same time, and is used to control the opening and closing of the gas pipeline and the switching of the gas channel;

Refrigerator, the refrigerator is connected to the gas pipeline between the sampling valve and the three-way valve through an insulated pipe, and is used to provide a local low-temperature environment; the outside of the insulated pipe is sequentially arranged from the inside to the outside. The sleeve is equipped with a heat-conducting tube and an insulating tube, the heat-conducting tube is used to increase the heat transfer contact area, and the insulating tube is used to block environmental heat exchange;

Heating piece, the heating piece is arranged on the gas pipeline between the insulated pipe and the three-way valve, and is used to heat the pipeline and vaporize or liquefy the water vapor solidified inside the pipeline;

An air pump, the air inlet of the air pump is connected to the three-way valve, used to remove gasified or liquefied water vapor.

As a further optional design of this technical solution, the sampling valve adopts a normally closed valve and is connected to the sampling device and the gas pipeline through the first vacuum connection ferrule; the three-way valve adopts a normally closed valve and connects with the gas pipeline through the first vacuum connection sleeve; Two vacuum ferrules are connected in series in the gas pipeline; the air pump adopts a programmable pump.

As a further optional design of this technical solution, the heat-conducting pipe is a first tubular sleeve made of a good conductor of heat. The first tubular sleeve is in close contact with the gas pipeline and is wrapped inside it. ;

The heat-insulating tube is a second tubular casing made of a poor conductor of heat, and the second tubular casing is in close contact with the heat-conducting tube and wraps it inside;

The insulating tube is a third tubular casing made of a poor conductor of heat. The third tubular casing is in close contact with the insulating tube and wraps it inside.

As a further optional design of this technical solution, the refrigerator is embedded in the heat-conducting pipe through cold fingers and is in close contact with it; the outside of the base of the refrigerator is also provided with a heat sink that closely fits the heat pipe.

As a further optional design of this technical solution, the injection valve includes a solenoid valve or a needle valve; the heating plate includes a Peltier or resistance wire; the three-way valve includes a vacuum three-way solenoid valve and a three-way needle valve. , a three-way valve body I based on the transformation of a multi-way valve or a three-way valve body II based on a three-way pipe connected in series with two two-way valves; the refrigerator includes a Stirling refrigerator or a semiconductor refrigerator; the mass spectrometer Instruments include time-of-flight mass spectrometers, ion trap mass spectrometers, or quadrupole mass spectrometers.

As a further optional design of this technical solution, the sampling device includes a membrane sampling device or a headspace sampling device, and the air outlet of the membrane sampling device or the headspace sampling device is connected with the inlet of the gas pipeline. The gas port is connected to achieve online removal of water vapor in the laboratory or external factory;

Alternatively, the air outlet of the membrane sampling device is connected to the air inlet of the gas pipeline, the entire online condensing water removal device is placed inside the pressure-bearing cabin, and the membrane sampling device is connected to the pressure-bearing cabin. The cabin is connected through a water vapor separation device, and the pressure-bearing cabin is placed in a liquid environment to realize online water removal of the in-situ detection mass spectrometer.

The online condensing water removal device of this technical solution can, on the one hand, condense the water vapor in the sample to be tested by connecting a refrigerator to the gas pipeline serving as the channel for the sample to be tested, thereby realizing the online analysis process of gaseous samples using a mass spectrometer. Not affected by water vapor; at the same time, by setting up the combined structure of heat insulation tube + heat conduction tube + heat insulation tube, efficient heat conduction and multi-layer insulation of the water vapor condensation part are achieved, which not only effectively reduces the cooling power consumption, but also greatly shortens the cooling time. Preheat time. On the other hand, by installing heating plates and air pumps on the gas pipeline downstream of the refrigerator, condensate water removal after online analysis is achieved.

Furthermore, the online condensing water removal device of this technical solution uses the sampling valve and the three-way valve to switch modes, and the design of the gas pipeline without non-standard components effectively ensures the airtightness of the sampling pipeline and eliminates the need for It eliminates the interference of external substances caused by leakage; at the same time, the airtight design allows the device to be directly connected to the vacuum pipeline to achieve water vapor removal for ultra-low pressure injection, which is especially suitable for online water removal of mass spectrometers.

Another technical solution adopted by the present invention to solve the technical problem is:

An online condensation water removal method suitable for mass spectrometers, based on the online condensation water removal device suitable for mass spectrometers, including the following steps:

S100. First turn on the mass spectrometer and perform online analysis of the gaseous sample in the cooling mode; at this time, the refrigerator of the online condensing water removal device is in working state, and its drainage pump is in non-working state;

S200. Turn off the mass spectrometer again, generate and discharge the condensed water in the gas pipeline in the heating mode; and at this time, the refrigerator of the online condensing water removal device is not working, and its drainage pump is working.

As a further optional design of this technical solution, step S100 specifically includes:

S101. Keep the air pump closed, set the target cooling temperature and turn on the refrigerator;

S102. When the feedback cold finger temperature of the refrigerator reaches the target cooling temperature, open the injection valve; at the same time, operate the three-way valve so that the end connected to the mass spectrometer is connected and the end connected to the air pump is closed;

S103. Turn on the mass spectrometer and perform sample analysis.

As a further optional design of this technical solution, step S200 specifically includes:

S201. Close the injection valve and operate the three-way valve at the same time so that the end connected to the mass spectrometer is closed and the end connected to the air pump is connected;

S202. Turn off the refrigerator and stop cooling;

S203. Open the heating plate to increase the temperature of the gas pipeline, thereby liquefying or vaporizing the solidified condensed water; at the same time, open the air pump to discharge the liquefied or vaporized water vapor from the exhaust hole of the air pump;

S204. Restart detection or stop the detection work of step S100 according to requirements.

Compared with related technologies, the present invention's online condensation water removal method suitable for mass spectrometers is based on the online condensation water removal device suitable for mass spectrometers, and its operation steps are the same as those of the online condensation water removal method. The water device has the same composition, structure and functions, so it must also have a series of technical advantages of the above-mentioned online condensation water removal device suitable for mass spectrometers. It also achieves good air tightness and efficient thermal conductivity, and can shorten the Preheating time, reducing water removal power consumption, simple structure, easy to build, no consumables, and recyclable technical effects.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples.

Figure 1 is a schematic structural diagram of an online condensation water removal device according to an embodiment of the present invention.

Figure 2 is a schematic structural diagram of an online condensation water removal device according to another embodiment of the present invention.

Explanation of the meaning of the reference marks in the figure:

1-on-line condensation water removal device; 11-sampling valve; 12-three-way valve; 13-refrigerator; 131-insulated tube; 1311-cold finger; 132-heat-conducting tube; 133-insulated tube; 134-base ; 1341-heat sink; 14-heating plate; 15-air pump; 151-exhaust hole; 2-sampling device; 3-gas pipeline; 4-mass spectrometer; 5-pressure chamber; 51-water vapor separation device .

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 described embodiments These are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

First embodiment

Figure 1 shows a schematic structural diagram of a preferred embodiment of the present invention. In the figure, there is an online condensation water removal device 1 suitable for a mass spectrometer 4. The mass spectrometer 4 and the sampling device 2 pass through a gas pipeline. 3 are connected, and the gas pipeline 3 serves as a channel for the sample to be tested; the online condensing water removal device 1 includes:

Sampling valve 11. The sampling valve 11 is provided on the gas pipeline 3 close to the side of the sampling device 2 and is used to control the on-off of sampling;

Three-way valve 12. The three-way valve 12 is arranged on the gas pipeline 3 on the side close to the mass spectrometer 4, and is connected to the air pump 15 for controlling the on and off of the gas pipeline and switching of the gas channel;

Refrigerator 13, the refrigerator 13 is connected to the gas pipeline between the sampling valve and the three-way valve 12 through an insulated pipe 131, and is used to provide a local low-temperature environment; the insulated pipe 131 There are heat-conducting tubes 132 and insulating tubes 133 arranged on the outside from the inside to the outside. The heat-conducting tubes 132 are used to increase the heat transfer contact area, and the insulating tubes 133 are used to block environmental heat exchange;

Heating piece 14. The heating piece 14 is arranged on the gas pipeline 3 between the insulated pipe 133 and the three-way valve 12, and is used to heat the pipeline and vaporize or liquefy the water vapor solidified inside the pipeline;

Air extraction pump 15, the air inlet of the air extraction pump 15 is connected to the three-way valve 12, used to remove gasified or liquefied water vapor.

In a further optional implementation of Embodiment 1 of the present invention, the sampling valve 11 adopts a normally closed valve and is connected to the sampling device 2 and the gas pipeline 3 through a first vacuum connection ferrule respectively; the three-way valve 12 adopts a normally closed valve and is connected in series to the gas pipeline 3 through a second vacuum ferrule; the air pump 15 adopts a programmable pump.

In a further optional implementation of Embodiment 1 of the present invention, the heat pipe 132 is a first tubular sleeve made of a good conductor of heat, and the first tubular sleeve is in close contact with the gas pipeline 3 and wrap it up;

The heat-insulating tube 131 is a second tubular casing made of a poor conductor of heat. The second tubular casing is in close contact with the heat-conducting tube 132 and wraps it inside;

The insulating tube 133 is a third tubular casing made of a poor conductor of heat. The third tubular casing is in close contact with the insulating tube 131 and wraps it inside.

In a further optional implementation of Embodiment 1 of the present invention, the refrigerator 13 is embedded in the heat transfer pipe 132 through the cold finger 1311 and is in close contact with it; Combined heat sink 1341.

In a further optional implementation of Embodiment 1 of the present invention, the sampling valve 11 includes a solenoid valve or a needle valve; the heating plate 14 includes a Peltier or resistance wire; and the three-way valve 12 includes a vacuum three-way A solenoid valve, a three-way needle valve, a three-way valve body I based on a multi-way valve modification, or a three-way valve body II based on a three-way pipe connected in series with two two-way valves; the refrigerator 13 includes a Stirling refrigerator Or a semiconductor refrigerator; the mass spectrometer 4 includes a time-of-flight mass spectrometer, an ion trap mass spectrometer or a quadrupole mass spectrometer.

In a further optional implementation of Embodiment 1 of the present invention, the sampling device 2 includes a membrane sampling device or a headspace sampling device, and the air outlet of the membrane sampling device or the headspace sampling device is connected to the air outlet of the membrane sampling device or the headspace sampling device. The air inlets of the gas pipeline 3 are connected and used to achieve online removal of water vapor in the laboratory or external factory.

Second embodiment

In another embodiment 2 shown in Figure 2, an online condensation water removal device 1 suitable for mass spectrometers is the same as the first embodiment 1 in terms of technical solutions and further improvement plans, with only the difference The difference lies in the application scenarios, that is,

In the specific implementation of Embodiment 2 of the present invention, the sampling device 2 includes a membrane sampling device, the air outlet of the membrane sampling device is connected to the air inlet of the gas pipeline 3, and the online condensation device The whole type water removal device 1 is placed inside the pressure chamber 5. The membrane sampling device and the pressure chamber 5 are connected through a water vapor separation device 51. The pressure chamber 5 is placed in a liquid environment to achieve the original purpose. On-line water removal by bit detection mass spectrometer 4.

In view of the problem that the current online water removal device is not suitable for the mass spectrometer 4 and the problem of high power consumption caused by poor heat insulation effect, both the first embodiment 1 and the second embodiment 2 of the present invention combine the condensation technology and the temperature can be With the advantages of adjustment, small size, low power consumption, no need to replace consumables, continuous long-term use, and the characteristics of extremely small injection volume of the mass spectrometer 4, a low power consumption, high airtightness, suitable for mass spectrometers is proposed 4’s online condensation water removal device specifically achieves the following technical advantages:

1) The online condensing water removal device of the present invention has good air tightness. While avoiding gas leakage from contaminating the sample to be tested, the device can be connected in series to the vacuum pipeline to achieve online water removal in a high vacuum environment, especially Suitable for online water removal of mass spectrometer 4;

2) The online condensation water removal device of the present invention, the high-efficiency heat conduction and multi-layer insulation design related to the refrigerator 13 shorten the device preheating time and reduce the water removal power consumption;

3) The online condensing dewatering device 1 of the present invention does not rely on manual operation and has the ability to work continuously for a long time;

4) The online condensing water removal device 1 of the present invention has a simple structure, is easy to set up, uses no consumables, and can be recycled.

Third embodiment

Embodiment 3 of the present invention is oriented to the field of gaseous sample analysis. In view of the water vapor removal requirements of gaseous samples, in order to solve the problem that the current online water removal device is not suitable for the mass spectrometer 4 and the problem of poor heat insulation effect resulting in high power consumption, it is also proposed An online condensation water removal method with low power consumption and high airtightness suitable for the mass spectrometer 4 is proposed. Refer to Figure 1 and Figure 2. It is carried out based on the online condensation water removal device 1 suitable for the mass spectrometer 4. , including the following steps:

S100, first turn on the mass spectrometer 4, and perform online analysis of gaseous samples in the cooling mode; at this time, the refrigerator 13 of the online condensing water removal device 1 is in the working state, and its drainage pump is in the non-working state;

S200, turn off the mass spectrometer 4 again, generate and discharge the condensed water in the gas pipeline 3 in the heating mode; and at this time, the refrigerator 13 of the online condensing dewatering device 1 is not working, and its drainage pump is in the working status.

In a further optional implementation of Embodiment 3 of the present invention, step S100 specifically includes:

S101. Keep the air extraction pump 15 closed, while setting the target cooling temperature and turning on the refrigerator 13;

S102. Until the temperature of the cold finger 1311 fed back by the refrigerator 13 reaches the target cooling temperature, open the injection valve 11; at the same time, operate the three-way valve 12 so that the end connected to the mass spectrometer 4 is connected and the end connected to the air pump 15 is closed;

S103. Turn on the mass spectrometer 4 and perform sample analysis.

In a further optional implementation of Embodiment 3 of the present invention, step S200 specifically includes:

S201. Close the injection valve 11 and operate the three-way valve 12 at the same time so that the end connected to the mass spectrometer 4 is closed and the end connected to the air pump 15 is connected;

S202. Turn off the refrigerator 13 and stop cooling;

S203. Open the heating plate 14 to increase the temperature of the gas pipeline 3, thereby liquefying or vaporizing the solidified condensed water; at the same time, open the air pump 15 to discharge the liquefied or gasified water vapor from the exhaust hole 151 of the air pump 15;

S204. Restart detection or stop the detection work of step S100 according to requirements.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications and equivalent changes made to the above embodiments based on the technical essence of the present invention will fall within this scope. within the scope of protection of the invention.

Claims (9)

1. An on-line condensing type water removing device suitable for a mass spectrometer is characterized in that the mass spectrometer is communicated with a sample injection device through a gas path pipeline, and the gas path pipeline is used as a channel of a sample to be detected; the on-line condensation type water removal device is characterized by comprising:

the sample injection valve is arranged on a gas path pipeline close to one side of the sample injection device and used for controlling sample injection on-off;

the three-way valve is arranged on a gas path pipeline close to one side of the mass spectrometer and is communicated with the air pump at the same time and used for controlling gas path on-off and gas path channel switching;

the refrigerator is connected to a gas path pipeline between the sample injection valve and the three-way valve through a heat insulation pipe and is used for providing a local low-temperature environment; the heat insulation pipe is sequentially sleeved with a heat conduction pipe and a heat insulation pipe from inside to outside, the heat conduction pipe is used for increasing the heat transfer contact area, and the heat insulation pipe is used for blocking environmental heat exchange;

the heating sheet is arranged on the gas path pipeline between the heat insulation pipe and the three-way valve and is used for realizing pipeline temperature rise and gasifying or liquefying solidified water vapor in the pipeline;

and an air suction pump, wherein an air inlet of the air suction pump is connected to the three-way valve and is used for removing gasified or liquefied water vapor.

2. The on-line condensing type water removing device for mass spectrometer according to claim 1, wherein the sample injection valve adopts a normally closed valve and is respectively connected with the sample injection device and the gas path pipeline through a first vacuum connection clamping sleeve; the three-way valve adopts a normally closed valve and is connected in series in the gas circuit pipeline through a second vacuum clamping sleeve; the air pump adopts a programmable pump.

3. An on-line condensing water trap for a mass spectrometer according to claim 1 or 2 characterized by the fact that said heat pipe is a first tubular sleeve made of a hot good conductor in close contact with and enveloping said gas path conduit;

the heat insulation pipe is a second tubular sleeve made of a heat poor conductor, and the second tubular sleeve is tightly contacted with the heat conduction pipe and wraps the heat conduction pipe;

the thermal insulation pipe is a third tubular sleeve made of a poor conductor of heat, which is in close contact with and encloses the thermal insulation pipe.

4. An on-line condensing water removal device for a mass spectrometer according to claim 3 wherein said refrigerator is embedded in said heat pipe by cold fingers and in intimate contact therewith; and a radiating fin closely attached to the base of the refrigerator is further arranged on the outer side of the base of the refrigerator.

5. The on-line condensing water-removal device for a mass spectrometer of claim 4, wherein said sample valve comprises a solenoid valve or needle valve; the heating sheet comprises a Peltier or a resistance wire; the three-way valve comprises a vacuum three-way electromagnetic valve, a three-way needle valve, a three-way valve body I based on multi-way valve transformation or a three-way valve body II based on three-way pipe serial connection of two-way valves; the refrigerator comprises a Stirling refrigerator or a semiconductor refrigerator; the mass spectrometer comprises a time-of-flight mass spectrometer, an ion trap mass spectrometer or a quadrupole mass spectrometer.

6. The on-line condensing water-removing device for mass spectrometer according to claim 5, wherein said sample-feeding device comprises a membrane sample-feeding device or a headspace sample-feeding device, the air outlet of said membrane sample-feeding device or headspace sample-feeding device is connected with the air inlet of said air channel pipe for on-line removing of water vapor in laboratory or in factory;

or, the gas outlet of the membrane sample injection device is connected with the gas inlet of the gas path pipeline, the on-line condensation type water removal device is integrally arranged in the pressure cabin, the membrane sample injection device is connected with the pressure cabin through the water-vapor separation device, and the pressure cabin is arranged in a liquid environment and is used for realizing on-line water removal of the in-situ detection mass spectrometer.

7. An on-line condensing water removal method for mass spectrometers, characterized by being based on the on-line condensing water removal device for mass spectrometers according to any of claims 1-6, comprising the following steps:

s100, firstly starting a mass spectrometer, and carrying out online analysis of a gaseous sample in a refrigeration mode; at the moment, the refrigerator of the online condensation type water removing device is in a working state, and the drainage pump of the refrigerator is in a non-working state;

s200, closing the mass spectrometer again, and generating and discharging condensed water in the gas pipeline in a heating mode; and at the moment, the refrigerator of the online condensation type water removal device is in a non-working state, and the drainage pump is in a working state.

8. The on-line condensation type water removal method for mass spectrometer as claimed in claim 7, wherein said step S100 comprises:

s101, keeping the air pump closed, setting target refrigeration temperature and starting the refrigerator;

s102, opening a sample injection valve until the feedback cold finger temperature of the refrigerator reaches the target refrigeration temperature; simultaneously, the three-way valve is operated to be communicated with the connecting end of the mass spectrometer and the air pump are closed;

s103, starting the mass spectrometer to analyze the sample.

9. An on-line condensation type water removal method for a mass spectrometer according to claim 7 or 8, wherein said step S200 specifically comprises:

s201, closing a sample injection valve, and simultaneously operating a three-way valve to close the end connected with the mass spectrometer and conduct the end connected with the air pump;

s202, turning off the refrigerator, and stopping refrigeration;

s203, opening the heating plate to raise the temperature of the gas path pipeline, and liquefying or gasifying the solidified condensed water; simultaneously opening the air pump to discharge liquefied or gasified water vapor from the exhaust hole of the air pump;

s204, restarting the detection or stopping the detection in the step S100 according to the requirement.