阅读说明：本技术 一种用于微量气体连续自动配制的系统和方法 (System and method for continuously and automatically preparing trace gas ) 是由 高鹏 盛武林 于 2021-01-12 设计创作，主要内容包括：一种用于微量气体连续自动配制的系统和方法,微量气体配制领域。本发明的系统包括主气控制单元、微量气体控制单元、平衡气控制单元、切换阀单元、气体混合单元、输送控制单元。本发明用于微量气体连续自动配制的方法,采用定量环向具有定量的主成分气体的气袋供应定量的微量气体,混匀后,再经过连续定比例配气的方式,做进一步的连续化混气。本发明适应性强,有利于实验或生产中的使用气体组分连续衔接,包括不同的种类,可以减少对比技术中容积法所需要的少量气体也需要大量气体配制的不灵活和浪费的问题,也能够避免连续法中成分变动需要更换阻尼毛细管等引起中断的问题。(A system and a method for continuously and automatically preparing trace gas, belonging to the field of trace gas preparation. The system comprises a main gas control unit, a micro gas control unit, a balance gas control unit, a switching valve unit, a gas mixing unit and a conveying control unit. The invention relates to a method for continuously and automatically preparing trace gas, which adopts a quantitative ring to supply quantitative trace gas to an air bag with quantitative main component gas, and further continuously mixes the gas in a continuous fixed proportion gas distribution mode after uniformly mixing the gas. The invention has strong adaptability, is beneficial to the continuous connection of used gas components in experiments or production, comprises different types, can reduce the problems of inflexibility and waste of a small amount of gas and a large amount of gas required by a volume method in the comparison technology, and can also avoid the problem of interruption caused by the fact that the damping capillary tube needs to be replaced when the components change in the continuous method.)

1. A system for continuous and automatic preparation of trace gas is characterized by comprising a main gas control unit (1), a trace gas control unit (2), a balance gas control unit (3), a switching valve unit (4), a gas mixing unit (6) and a conveying control unit (5); one side of the main gas control unit (1) is connected with the micro gas control unit (2), the other side of the main gas control unit (1) is connected with one side of the switching valve unit (4), one side of the switching valve unit (4) is connected with the conveying control unit (5), the other side of the switching valve unit (4) is connected with one side of the gas mixer unit (6), and the other side of the gas mixer unit (6) is connected with the balance gas control unit (3);

wherein the main gas control unit (1) comprises a main gas bottle (10), a pressure reducing valve a (11), a pressure gauge a (12), a switch valve a (13), a switch valve b (15a) going to the switching valve unit (4), and a gas flow controller a (14); the main gas bottle (10) is connected with one side of a pressure reducing valve a (11), the other side of the pressure reducing valve a (11) is connected with one side of a pressure gauge a (12), the other side of the pressure gauge a (12) is connected with one side of a switch valve a (13), the other side of the switch valve a (13) is connected with one side of a gas flow controller a (14), the other side of a switch valve b (15a) is connected with a four-way valve (41) in the switching valve unit (4), and a six-way valve a (24a) is arranged between the gas flow controller a (14) and the switch valve b (15 a).

2. The system for the continuous automatic preparation of micro gas according to claim 1, wherein the micro gas control unit (2) comprises a sample gas cylinder (20), a pressure reducing valve b (21), a pressure gauge b (22), a switch valve d (23a), a six-way valve a (24a) with a dosing ring a (25a), a vent valve a (26a), a vent port a (26 c); wherein the sample gas bottle (20) is connected with the vent port a (26c), and a pressure reducing valve b (21), a pressure gauge b (22), a switch valve d (23a) and a vent valve a (26a) are sequentially arranged between the sample gas bottle (20) and the vent port a (26 c); a six-way valve a (24a) with a dosing ring a (25a) is arranged between the switch valve d (23a) and the blow-down valve a (26 a).

3. The system for the continuous and automatic preparation of micro-gas according to claim 1, wherein the balance gas control unit (3) comprises a balance gas bottle (30), a pressure reducing valve c (31), a pressure gauge c (32), a switch valve f (33), a vent valve c (34a), a vent port b (34 b); the balance gas cylinder (30) is connected with the vent hole b (34b), and a pressure reducing valve c (31), a pressure gauge c (32), a switch valve f (33) and a vent valve c (34a) are sequentially arranged between the balance gas cylinder (30) and the vent hole b (34 b).

4. The system for the continuous automatic dispensing of a trace amount of gas according to claim 1, wherein the switching valve unit (4) comprises a four-way valve (41), and the four-way valve (41) is simultaneously connected to the on-off valve b (15a) in the main gas control unit (1), the on-off valve g (51a) in the delivery control unit (5), the first air bag (68a) and the second air bag (68b) in the gas mixing unit (6).

5. The system for the continuous and automatic preparation of trace gas according to claim 1, wherein a switch valve g (51a) is provided in the delivery control unit 5, one side of the switch valve g (51a) is connected to the four-way valve (41), the other side of the switch valve g (51a) is connected to the discharge port (54b), and a buffer tank (52a), a flow controller (53a) and a gas flow controller b (54a) are provided between the switch valve g (51a) and the discharge port (54b) in sequence; a pipeline between the switch valve g (51a) and the four-way valve (41) is connected with one side of an emptying valve (55a), the other side of the emptying valve (55a) is connected with an emptying port a (55c), and a damping pipe (55b) is arranged between the emptying valve (55a) and the emptying port a (55 c).

6. The system for the continuous and automatic preparation of trace gases according to claim 1, wherein the gas mixing unit (6) is provided with a mixer cylinder (62), the top of the mixer cylinder (62) is provided with a mixer sealing cover (61), the bottom of the mixer cylinder (62) is connected with a liquid outlet (65b), and a liquid outlet valve (65a) is arranged between the bottom of the mixer cylinder (62) and the liquid outlet (65 b); the side surface of the mixer cylinder (62) is connected with a liquid level meter (64) and a temperature detector (66 c); an upper clapboard (67c) and a lower clapboard (67a) are arranged in parallel in the vertical direction in the mixer cylinder (62), a first air bag (68a) and a second air bag (68b) are arranged between the upper clapboard (67c) and the lower clapboard (67a), and a middle clapboard (67c) is arranged between the first air bag (68a) and the second air bag (68 b); a stirrer (66b) and a heater (66a) are arranged below the lower partition plate (67a), the side surface of the mixer cylinder (62) is also connected with a beating opening b (63c), and a mixer pressure gauge (63a) and a pressure safety valve (63b) are sequentially arranged between the mixer cylinder (62) and the beating opening b (63 c).

7. The system for continuous and automatic micro-gas preparation according to claim 6, wherein the gas bag is provided with a plurality of electric squeezers (69a) and electric squeezers (69b) which can vibrate periodically or reciprocate and are used for squeezing the gas bag, and the electric squeezers are used for accelerating the gas in the gas bag to be mixed uniformly.

8. A system for the continuous automatic dispensing of micro-gases according to claim 1, characterized in that the temperature of the gas mixer unit (6) is higher than room temperature.

9. A method for continuously and automatically preparing gas by using the system of claim 1, which is characterized in that quantitative micro gas is supplied to an air bag with quantitative main component gas by a quantitative ring, and after uniform mixing, further continuous gas mixing is performed in a continuous gas distribution mode with fixed proportion.

Technical Field

The invention belongs to the field of trace gas preparation, and particularly relates to a system and a method for continuously and automatically preparing trace gas.

Background

The preparation of trace gas generally refers to the component distribution ratio of the target component in the total gas, wherein the content of the target component is mmol/mol or even mu mol/mol or less. The trace gas preparation technology is widely applied and becomes a common application technology in the fields of conventional chemical reaction, fuel cells, environmental detection, agricultural planting, atmospheric simulation, precise electronics, medical treatment, biology and the like. The trace gas preparation method mainly comprises five methods, namely a weight method, a pressure ratio method, a mass flow ratio method, a static capacity method and a permeation tube method, wherein the first three methods are widely applied.

Due to the increasing application requirements and the imperfect technology, many attempts have been made in recent years to provide convenient, fast and accurate gas distribution technology.

For example, patent CN102698645B and CN102921338B adopt a single-stage or multi-stage container with a constant volume, and the method of supplementing different gases and detecting mixture, and then adjusting the ratio to achieve a set ratio is intermittent and can be used only when the total volume is larger than at least one. Patent CN104162372B provides a water-gas displacement technology, which belongs to intermittent supply, does not have the convenient condition of large flow control, and needs to maintain accurate pressure stability in the environment receiving the gas, otherwise, the rapid volume change automatically occurs to cause the large change of output flow speed, including suck-back.

Patents CN104248919B and CN211913375U provide stable flow control for trace gas in the mixture ratio by using a damping tube, and setting and changing the length of the damping tube require detection and verification, which is inconvenient in application and does not have the capability of automatically and rapidly changing components. CN104303126B provides the purpose of adjusting the mixture ratio by measuring the change of molecular weight, but is not suitable for gases with similar molecular weight or small addition ratio.

Patent CN201711444272.0 uses a cavitation mixer, which has the advantages of continuous air supply and good mixing effect, but is limited by the jet flow principle, and the flow range and ratio thereof are limited to a certain extent.

Patent CN104785134B provides an isobaric gas proportioning method, which is suitable for gas proportioning with close flow rate. Patent CN104959049B provides a large-proportion gas distribution technology, but the total mass ratio of trace gas is large by adopting a weighing method, so that the method is suitable for occasions using a large amount of gas.

CN111220445A proposes a dynamic gas distribution technology, which adopts a membrane diffusion mode to prepare diluent gas, and is mainly used in the occasion of volatile liquid.

CN203853061U proposes a continuous gas distribution technology, which is to continuously and intermittently prepare a plurality of constant volume gas mixtures for a plurality of independent containers by adopting a pressure supplementing and supplementing mode. CN102921338B belongs to the quantitative ring gas distribution mode of four-way valve or six-way valve, is suitable for normal pressure gas distribution, has no adaptability to output higher than atmospheric pressure, continuous gas supply and on-line variable proportion,

patents CN208800039U, CN205988708U, CN209155690U, etc. adopt a constant volume high pressure gas cylinder rotation method to provide a uniform mixing method of preparing mixed gas with constant volume, which has large volume, low efficiency, and is more difficult to mix trace components uniformly.

The existing proposed technology needs to be improved in the aspects of continuity, variability, automation, scale or total flexibility, etc., so as to meet the increasing technical requirements of various industries, and the technology has many problems to be solved or improved.

Disclosure of Invention

The invention provides a system and a method for continuously and automatically preparing trace gas, aiming at the defects, the system has the characteristics of continuous adjustability of gas components and wide range of proportion change, and is beneficial to various application occasions needing to quantitatively prepare a plurality of gas mixtures, in particular to preparation of trace components. Either for continuous supply of the gas mixture or for intermittent dosing.

The system for solving the technical problem comprises a main gas control unit, a trace gas control unit, a balance gas control unit, a switching valve unit, a gas mixing unit and a conveying control unit.

The invention also discloses a method for continuously and automatically preparing trace gas, which adopts a quantitative ring to supply quantitative trace gas to an air bag with quantitative main component gas, and further continuously mixes the gas after mixing the gas uniformly and then distributing the gas in a continuous fixed proportion manner.

Has the advantages that: the invention discloses a system and a method for preparing trace gas, which have the characteristics of continuous adjustability of gas components and large-range proportion change, and are beneficial to various application occasions needing to quantitatively prepare a plurality of gas mixtures, in particular to preparation of trace components. Either for continuous supply of the gas mixture or for intermittent dosing.

The invention has the advantages that the direct hardware operation of gas distribution can be carried out without manpower in the operation, the automatic preparation and supply of concentration setting are facilitated, the provided component continuously changes technology in an enlarged range, and more technical applications are facilitated.

The invention has strong adaptability, is beneficial to continuous connection of used gas components in experiments or production, comprises different types, can reduce the problems of inflexibility and waste that a small amount of gas required by a volume method in the comparison technology also needs a large amount of gas to be prepared, can also avoid the problem that the components in the continuous method need to be changed and the damping capillary tube needs to be replaced to cause interruption, and can be used for improving the steel cylinder rolling technology, thereby reducing the cost and providing favorable conditions for the continuity and the quick progress of research or production.

Drawings

Fig. 1 is a main structure diagram of the system.

FIG. 2 is a basic configuration diagram.

FIG. 3 is a schematic diagram of a six-way valve injection.

FIG. 4 is a schematic diagram of distribution of a plurality of principal components.

FIG. 5 is a partial schematic view of further dilution.

FIG. 6 is a partial schematic view of the use of multiple switching valves and multiple air bags.

FIG. 7 is a schematic of a method of using two dosing rings for a single trace gas.

FIG. 8 is a schematic view of a method of using an extruder for the gas mixer.

As shown in the figure, 1 is a main gas control unit, 1' is a second main component control, 10 is a main gas cylinder, 11 is a pressure reducing valve a, 12 is a pressure gauge a, 13, a switch valve a, 14, a gas flow controller a, 15a, a switch valve b, 15b, a switch valve c, 2 is a trace gas control unit, 20 is a sample gas cylinder; 21. pressure reducing valves b, 22, pressure gauges b, 23a, switch valves d, 23b, switch valves e, 24a, six-way valves a, 24b, six-way valves b, 25a, dosing rings a, 25b, dosing rings b, 26a, blow valves a, 26b, blow valves b, 26c, blow ports a, 3, balance gas control unit, 30, balance gas cylinder, 31, pressure reducing valves c, 32, pressure gauges c, 33, switch valves f, 34a, blow valves c, 34b, blow ports b, 4, switching valve unit, 41, four-way valve, 42a, five-way inlet valve, 42b, common inlet valve, 43a, five-way outlet valve, 43b, common outlet valve, 5, delivery control unit, 51a, switch valves g, 51b, switch valves h, 52a buffer tanks a, 52b, buffer tanks b, 53a, flow controllers a, 53b, flow controllers b, 54a, gas controllers b, 54b, discharge ports 55a, 55b, damping valves b, 55c, a vent hole a, 6, a gas mixer unit, 61, a mixer sealing cover, 62, a mixer cylinder, 63a, a mixer pressure gauge, 63b, a pressure safety valve, 63c, a vent hole b, 64, a liquid level meter, 65a, a liquid discharge valve, 65b, a liquid discharge port, 66a, a heater, 66b, a stirrer, 66c, a temperature measuring meter, 67a, a lower partition plate, 67b, a middle partition plate, 67c, an upper partition plate, 68a, a first air bag, 68b, a second air bag, 68c, a third air bag, 68d, a fourth air bag, 60a, an electric squeezer a, 69b and an electric squeezer.

Detailed Description

The present invention will be further described with reference to the following examples.

After the gas source is determined, namely each component gas supply source, the whole system can realize unmanned operation by adopting a universal automatic control technology under the control targets of manual input of gas proportion, pressure, flow, proportion change time of flow and the like, so that the principle and the structure of realizing the gas preparation process and method are taken as key points, and related automatic technical management schemes are not described.

If corrosion and adsorption characteristics exist in all components, the gas flow needs to have certain conditions along various wall surfaces, including valve bodies, pipelines, joints, sealing elements, detection instruments, containers and the like, and all the components adopt materials with corrosion resistance and adsorption influence smaller than the output requirement, but the components are not the control characteristics of the invention and are not described again.

The invention is characterized in that each vent is connected with a discharge system, and corresponding treatment is carried out according to the main components and the properties of trace gas, such as the treatment of absorption, conversion, explosion prevention and the like of toxic substances or combustible substances, which belongs to the conventional technology in the industry, and the invention is not specially described.

Example 1

See fig. 1-3.

The system of the present embodiment includes a main gas control unit 1, a micro gas control unit 2, a balance gas control unit 3, a switching valve unit 4, a gas mixing unit 6, and a delivery control unit 5. One side of the main gas control unit 1 is connected with the micro gas control unit 2, the other side of the main gas control unit 1 is connected with one side of the switching valve unit 4, one side of the switching valve unit 4 is connected with the delivery control unit 5, the other side of the switching valve unit 4 is connected with one side of the gas mixer unit 6, and the other side of the gas mixer unit 6 is connected with the balance gas control unit 3.

Wherein the main gas control unit 1 includes a main gas cylinder 10, a pressure reducing valve a11, a pressure gauge a12, an on-off valve a13, an on-off valve b15a to the switching valve unit 4, and a gas flow controller a 14. The main gas bottle 10 is connected with one side of a pressure reducing valve a11, the other side of the pressure reducing valve a11 is connected with one side of a pressure gauge a12, the other side of the pressure gauge a12 is connected with one side of a switch valve a13, the other side of the switch valve a13 is connected with one side of a gas flow controller a14, the other side of the switch valve b15a is connected with a four-way valve 41 in the switching valve unit 4, and a six-way valve a24a is arranged between the gas flow controller a14 and the switch valve b15 a.

The micro gas control unit 2 comprises a sample gas bottle 20, a pressure reducing valve b21, a pressure gauge b22, an on-off valve d23a, a six-way valve a24a with a dosing ring a25a, a vent valve a26a and a vent port a26 c. Wherein the sample gas bottle 20 is connected with a vent port a26c, and a pressure reducing valve b21, a pressure gauge b22, a switch valve d23a and a vent valve a26a are sequentially arranged between the sample gas bottle 20 and the vent port a26 c; a six-way valve a24a with a dosing ring a25a is provided between the on-off valve d23a and the emptying valve a26 a.

The balance gas control unit 3 comprises a balance gas bottle 30, a pressure reducing valve c31, a pressure gauge c32, an on-off valve f33, a vent valve c34a and a vent port b34 b. The balance gas bottle 30 is connected with a vent b34b, and a pressure reducing valve c31, a pressure gauge c32, a switch valve f33 and a vent valve c34a are sequentially arranged between the balance gas bottle 30 and the vent b34 b.

The switching valve unit 4 includes a four-way valve 41, and the four-way valve 41 is connected to the on-off valve b15a in the main gas control unit 1, the on-off valve g51a in the conveyance control unit 5, the first bag 68a and the second bag 68b in the gas mixing unit 6.

A switch valve g51a is arranged in the conveying control unit 5, one side of the switch valve g51a is connected with the four-way valve 41, the other side of the switch valve g51a is connected with the discharge port 54b, and a buffer tank 52a, a flow controller 53a and a gas flow controller b54a are sequentially arranged between the switch valve g51a and the discharge port 54 b; the pipeline between the switch valve g51a and the four-way valve 41 is connected with one side of an exhaust valve 55a, the other side of the exhaust valve 55a is connected with an exhaust port a55c, and a damping pipe 55b is arranged between the exhaust valve 55a and the exhaust port a55 c.

The gas mixing unit 6 is provided with a mixer cylinder 62, a mixer seal cover 61 is provided on the top of the mixer cylinder 62, the bottom of the mixer cylinder 62 is connected with a liquid outlet 65b, and a liquid outlet valve 65a is provided between the bottom of the mixer cylinder 62 and the liquid outlet 65b. The mixer drum 62 is connected on its side to a level gauge 64 and a temperature gauge 66c. An upper partition plate 67c and a lower partition plate 67a are vertically arranged in parallel in the mixer cylinder 62, a first air bag 68a and a second air bag 68b are arranged between the upper partition plate 67c and the lower partition plate 67a, and a middle partition plate 67b is arranged between the first air bag 68a and the second air bag 68b. A stirrer 66b and a heater 66a are arranged below the lower partition plate 67a, the side surface of the mixer cylinder 62 is also connected with a stirring port b63c, and a mixer pressure gauge 63a and a pressure safety valve 63b are sequentially arranged between the mixer cylinder 62 and the stirring port b63 c.

Furthermore, a plurality of electric extruders 69a and 69b which can periodically vibrate or reciprocate and are used for extruding the air bag are arranged near the air bag, so that the uniform mixing of the air in the air bag is accelerated.

The temperature of the gas mixer unit 6 is controlled to be slightly higher than the room temperature, for example, controlled to be 40 ℃, which is beneficial to accelerating the uniform mixing of the gas in the gas bag. The agitator 66b provides intermittent agitation, creating water waves that provide turbulence to the air pocket and accelerated mixing of the air in the air pocket.

The main component gases may be the same or different, and the ratio of the main components to the trace amount is preferably within 1:10 or 1:50, but not limited to this range. Any gas component can be high-purity gas or compound gas. The main air is supplied to the air bag through the six-way valve a24a and the on-off valve b15a in accordance with the metering control.

When the trace gas is quantified in the quantitative ring a25a, the quantitative ring a25a is firstly purged by using the body gas through the vent valve a26a, and the consistency of the gas in the quantitative ring a25a and the gas in the sample gas bottle 20 of the trace gas is completed. The gas is supplied to the bag, the bag from which the gas has been discharged is selected, and the main gas control unit 1 blows a trace amount of the gas in the quantitative ring a25a into the bag using a quantitative amount of the main component gas. Then, mixing is performed and the inhomogeneous gas in the piping is discharged to the delivery control unit 5 through the switching valve unit 4 while the inlet of the on-off valve g51a is closed, and after a certain time of discharge, the evacuation valve 55a is closed again and the on-off valve g51a is opened.

The quantitative ring a25a may be provided with a constant pressure with the main gas source or may be provided with a different pressure control quantitative ring. The pressure gauge c32 detects the pressure value, converts the absolute quantity of the trace gas in the quantitative ring a25a according to the temperature and the pressure, can add the trace gas for a plurality of times in the process of filling the air bag, intermittently supplies the main component gas, and accumulatively keeps the total quantity of the main component to be added according to the measurement.

When the operation is finished or the mixer needs to be opened, the atmospheric valve c34a of the balance gas control unit 3 closes the supply switching valve f33 of the balance gas, opens the evacuation atmospheric valve c34a, and releases the gas pressure.

The gas mixer has a heater 66a, a thermometer 66c and a stirrer 66b, and the temperature is controlled to be slightly higher than the room temperature, for example, 40 ℃, which is beneficial to accelerating the uniform mixing of the gas in the gas bag. The agitator 66b provides intermittent agitation, creating water waves that provide turbulence to the air pockets and faster mixing of the gas within the air pockets.

The gas mixer is set to output the pressure required by the gas flow controller b54a corresponding to the highest pressure and the lowest pressure, and can be varied within a certain range without precise control during operation, such as 0.3-0.5 MPag, and the pressure is regulated by the balance gas control unit 3 to provide gas pressure to the container of the gas mixer unit 6. The volume of the air bag is 1.2 times of the volume of the mixed gas in a standard state after being distributed once according to the water volume, so that the air bag is prevented from expanding and bursting during pressure relief after being filled with gas. The mixer cylinder 62 has a certain space at its upper part which is not filled with water, and is pressurized up to the highest pressure of the inlet of the output gas flow controller b54a by using gas equilibrium, and the pressure relief valve 63b, the mixer pressure gauge 63a and the relief valve c34a control the highest pressure not to exceed a predetermined value together. When one air bag continuously outputs air, the air pressure is reduced, and balance air is used for supplement when the air pressure is lower than the lowest pressure value. One of the air bags outputs gas, and the other air bag prepares new gas. The both are switched by the switching valve unit 4 to keep the continuity of the supplied air. During the switching, the on-off valve g51a at the inlet end of the buffer tank is closed to stop the gas supply from the airbag directly to the gas flow controller b54a, and the buffer tank a52a is used to temporarily supply the gas to the gas flow controller b54 a.

The volume of the buffer tank a52a is set according to the air bag distribution time, the product gas output flow and the output gas pressure range before the gas flow controller b54a, and is specifically set to be larger than the product of the time and the flow rate multiplied by the gas pressure difference. For example, assuming a complete gas distribution time for the airbag is 1min, including the control valve switching time, the inflation time, the airbag mixing time, the intermediate pipeline purging time, and the stability increasing time, the flow output is 10NmL/min, the pressure before the flow controller is 0.3-0.5 MPag and the pressure after the flow controller is 0.2MPag, a 10mL buffer tank a52a with an effective volume can provide 20NmL of gas to the gas flow controller b54a when the gas pressure is reduced from 0.5MPag to 0.3MPag, i.e., a 2min buffer time. The method is specifically adjusted according to actual conditions.

The switching valve unit 4 selectively guides gas sources including one or more paths of gas output by the main gas control unit 1 and one or more paths of gas output by the micro gas control unit 2 into a plurality of gas bags in the gas mixer unit 6. The switching valve unit 4 also selectively introduces a plurality of paths of gas prepared from the gas bag of the gas mixer unit 6 to the delivery control unit 5, and selectively evacuates or introduces the gas into the selected buffer tank a52a through the evacuation valve 55a via the delivery control unit 5.

For each switching, purging of the replacement is required, including six-way valve a24a, dosing ring a25a, switching valve 41, gas pockets and various intermediate conduits which undergo gas composition changes during operation. When the trace gas is quantified in the quantitative ring a25a, the quantitative ring a25a is firstly purged by the body gas through the vent valve c34a of the trace gas control unit 2, and the gas in the quantitative ring a25a is consistent with that in the sample gas bottle 20. The gas is supplied to the mixer bag, the bag from which the gas has been discharged is selected, and a trace amount of the gas in the quantitative ring a25a is blown into the bag by using a quantitative amount of the main component gas. Then mixing is performed, the inlet switch valve g51a of the buffer tank a52a is closed, the uneven gas in the pipeline is discharged to the conveying control unit 5 through the switching valve 41, the emptying valve 55a is opened to be emptied, the damping pipe 55b plays a role in delaying, the emptying valve 55a is closed again after a certain time is discharged, the inlet switch valve g51a of the buffer tank a52a is opened, and the gas in the air bag continues to supply the mixed gas to the gas flow controller b54a through the buffer tank a52 a.

Because the change of the air pressure is generally small every day and is less than 1% in non-storm weather, normal pressure quantification can be adopted, the relative precision requirement of the air distribution with the general precision requirement of more than 1% can be met, and the quantitative correction requirement of one day can be met by one-time detection in practical use. The detection sampling port uses an emptying line emptying port of the output control unit.

Example 2

Referring to fig. 4, a diagram of the distribution of a plurality of principal components is shown.

This example is intended to illustrate one way of formulating a trace amount of gas for a plurality of main components.

Take nitrogen and oxygen to prepare accurate artificial air, and add trace amount of carbon monoxide as an example.

One of the main component gases is used, preferably an inert gas, in this case nitrogen.

In the case of using nitrogen gas as the main gas control unit 1 and oxygen gas as the second main component control unit, similarly to example 1, a trace amount of gas was fed into the gas mixer unit 6 through the dosing ring of the six-way valve and through the switching valve unit 4 to prepare a mixed gas in a set ratio. Then sent to a conveying control unit 5 through a switching valve unit 4 for constant flow output.

The micro gas control unit 2 can supply more than one micro gas to the gas mixer unit 6 by switching supply of different gases to the dosing ring a25a using a plurality of different kinds of gases connected in parallel.

Example 3

See fig. 5, a partial schematic of further dilution, in the same sense as reducing the trace gas content ratio.

One or more main component control units, such as the second main component control unit 1', are adopted to further mix with the mixed gas controlled by the conveying control unit 5 directly after the conveying control unit 5, and the second main component gas is mixed with the mixed gas prepared by the gas mixer unit 6 of the system again to obtain the amplification of the dilution factor of the trace gas again.

The second principal component gas may be the same as or different from the first principal component gas.

The main application characteristics of the method and the embodiment 2 are that the method is more suitable for large-flow gas distribution output, and the embodiment 2 is relatively more suitable for small-flow gas distribution output.

For example, 999.9ml of hydrogen was prepared by using 0.100ml of the quantitative ring a24a and controlling the main gas control unit 1, and 0.10mmol/mol of hydrogen sulfide in hydrogen gas was obtained in the gas pocket. After being output by the transmission control unit 5, the hydrogen sulfide gas is mixed with the high-purity hydrogen gas of 999mL/min output by the second main component control unit 1' at the speed of 1.00mL/min to obtain further diluted gas containing the hydrogen sulfide, and the content of the hydrogen sulfide is 0.10 mu mol/mol.

If the gas distribution is carried out 3 times by using the 0.100ml quantitative ring a24a, the main gas control unit 1 controls to prepare 999.7ml hydrogen, and the gas in the quantitative ring b25b is sent into the gas bag in times, so that 0.30mmol/mol of hydrogen sulfide in the hydrogen is obtained. After being output by the transmission control unit 5, the hydrogen sulfide gas is mixed with the high-purity hydrogen gas of 999mL/min output by the second main component control unit 1' at the speed of 1.00mL/min to obtain further diluted gas containing the hydrogen sulfide, and the content of the hydrogen sulfide is 0.30 mu mol/mol.

If a 1.00mL quantitative ring b25b is used and the main gas control unit 1 controls the make-up of 999mL hydrogen, the gas pocket is formed at 1.00mmol/mol, and mixed with 999mL/min of high purity hydrogen outputted from the second main component control 1' to give a hydrogen sulfide content of 1.00. mu. mol/mol. Compared with the method of directly preparing hydrogen sulfide content of 1.00 mu mol/mol by only using the main gas control unit 1 without using the second main component control 1', the technical method of using the second main component control 1' can provide larger final total flow rate, and improves stability and uniformity through secondary mixed gas preparation.

This approach is relatively more suitable for large flow gas supplies.

Example 4

Referring to fig. 6, this figure is used to explain the operation using a plurality of switching valves and a plurality of air bags.

In the switching valve unit 4, a plurality of 1-to-many switching valves, such as a five-way valve 42a, are used to switch the distribution of the gas from the raw material gas into 4 gas bags, such as a first gas bag 68a, a second gas bag 68b, a third gas bag 68c, and a fourth gas bag 68d, and a common inlet valve port 42b is used to switch the mixed gas having been mixed from the 4 gas bags to the conveyance control unit 5. Thus, the buffering mixing time and the regulation and control margin of gas distribution are increased, and the controllable difference of the trace proportion in each gas bag is included, namely, the same quantitative ring is used in different gas bags, but the times of adding trace gas are different, the proportion of the trace gas in the obtained gas bag is different, and then the proportion output by the conveying control unit 5 is changed accordingly.

Example 5

Referring to fig. 7, a schematic of a method for using two dosing rings for a single trace gas to continuously vary the delivered gas concentration over a large range, e.g., small flow variations, but with a relatively large trace gas content variation, e.g., a concentration variation range in continuous operation of more than 10 times, here assumed to be 100 times.

In the trace gas control unit 2, a two-way six-way valve and different quantitative rings thereof are adopted, low concentration in the range is prepared in a gas bag I68 a, and a small-volume quantitative ring a25a (0.100ml) is used for preparing 999.9ml of oxygen in nitrogen; preparation of this range in air pocket three 68c 999ml of oxygen in nitrogen were prepared using a large volume dosing ring b25b (1.00 ml). If the dosing ring b25b is continuously used 10 times for the air bag three 68c, the air bag three 68c can be formed to have a concentration 100 times higher than that of the air bag one 68a, so that it is possible to easily provide the transportation control unit 5 with a wide range of concentration variation conditions, and in combination with the structure of embodiment 3, that is, fig. 5, it is possible to generate a wide range of continuous trace gas content variations.

Instead of changing the dosing ring, the small-volume dosing ring a24a (0.100ml) may be used to prepare 1 air bag more times, and only the number of times of system switching control is large for the purpose of this example.

After being mixed uniformly and the gas in the middle pipeline is discharged, the mixture is sent to a conveying control unit 5. Wherein the switching valve g51a, the buffer tank a52a and the flow controller a53a are used for storing and buffering low-concentration gas, and the other switching valve h51b, the buffer tank b52b and the flow controller b53b are used for storing and buffering high-concentration gas. Therefore, concentration lag and unevenness caused by the concentration change of the two gases with different concentrations in the buffer tank by only one way storage switching are avoided.

Example 6

Aiming at preparing a small amount of gas with high dilution ratio, for example, adding a trace amount of hydrogen sulfide gas into high-purity hydrogen, preparing the high-purity hydrogen through the basic structure shown in fig. 1 and 2, directly preparing a small amount of premixed gas at one time, for example, 1.00mmol/mol gas of 1NL, and collecting the gas with the pressure of about 0.2-0.3 MPa into a sample gas cylinder 20 as raw material gas.

This raw material gas is used again in the trace gas control unit 2, and a mixed gas having a trace gas content of 1. mu. mol/mol at a low flow rate, for example, 1NL/min, can be prepared by supplying this gas to the quantitative ring a25 a.

The foregoing examples are provided for illustration and description of the invention only and are not intended to limit the invention to the scope of the described examples. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed.