CN111156933A - Test method for testing safe size of micro-channel - Google Patents
Test method for testing safe size of micro-channel Download PDFInfo
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- CN111156933A CN111156933A CN201811326845.4A CN201811326845A CN111156933A CN 111156933 A CN111156933 A CN 111156933A CN 201811326845 A CN201811326845 A CN 201811326845A CN 111156933 A CN111156933 A CN 111156933A
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- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B13/00—Measuring arrangements characterised by the use of fluids
Abstract
The invention relates to the field of chemical safety, and discloses a testing method for testing the safe size of a micro-channel, which is characterized by comprising the following steps of S1: -arranging a plurality of microchannels (13) of different sizes on a microchannel arrangement means (10); s2: pumping a plurality of microchannels (13) into vacuum by using a supply device (20) and then introducing gas to be measured; s3: under the preset condition, the micro-channel with the smallest size in the plurality of micro-channels (13) with different sizes is ignited by the ignition device (30) sequentially according to the size until the ignition is successful, and the micro-channel before the micro-channel with the successful ignition has the following size: the microchannel safety size of the gas to be measured under the predetermined condition. The testing method can simulate the condition of the combustible gas in the micro-channel under the actual working condition, determine the safe critical dimension of the channel and ensure the safe use of the combustible gas in the micro-channel.
Description
Technical Field
The invention relates to the field of chemical safety, in particular to a test method for testing the safety size of a micro-channel.
Background
The concept of micro-channel has been proposed for the first time since the last 80 century, and it is a hot point for research because of its small volume, large specific surface area, fast mass and heat transfer, high control precision and no amplification effect compared with the traditional chemical process. Today, miniaturized and integrated micro chemical equipment is widely applied in the fields of biological pharmacy, fine chemical engineering, biological detection and the like.
Micro-channel microreactors generally refer to a reactor in which chemical reactions are controlled in as small a space as possible, i.e., a reaction space having a size and number of extremely micro-or nano-scale is provided. Or a micro-reaction system in which various functions such as mixing, heat exchange, separation, and reaction performed by using microchannels are integrated. The application of the method is more and more extensive because of the advantages of short reaction time, high product quality and accurate process control.
In particular, its safety and environmental features are increasingly being used to modify existing processes. For example, the application of the micro chemical system in the production of dangerous chemicals was first developed by Dupont in the early 90 s of the last century, and a micro chemical device for synthesizing methyl isocyanate was successfully developed. However, the company has tried to synthesize hydrogen peroxide directly under 10% hydrogen atmosphere, but because of frequent explosion accidents, a pilot plant had to be shut down,
it is seen that research based on the explosion limit of microchannels, etc., is becoming more and more urgent. For microreactors, as the channel size decreases, collisions between radicals and reactive molecules decrease, and the probability of a radical colliding with the wall of the tube increases. When the micro-channel of the micro-reactor is small to a certain value, free radicals are quenched in the process of colliding with the tube wall due to the wall effect of the channel, and flame can not be transmitted.
However, how to determine whether the size of flame failure and the size of non-detonation occurring in the microchannel are related, and a test method for testing the safe channel size of combustible gas in situ in the microchannel has not been reported. In order to increase the utilization rate of the reaction material, it is desirable to increase the size of the microchannel as much as possible in order to increase the reaction flux as much as possible when the microchannel effect can be utilized. The use of combustible gases within the explosive limits using microfluidic technology has made it more and more urgent to change the existing process flow or develop new processes while ensuring process safety.
Disclosure of Invention
The invention aims to solve the problem that the safety critical dimension of a microchannel cannot be determined in the prior art, and provides a testing method for testing the safety dimension of the microchannel.
In order to achieve the above object, an aspect of the present invention provides a testing method for testing a safe size of a micro channel, comprising the steps of, S1: disposing a plurality of microchannels of different sizes onto a microchannel placement device; s2: vacuumizing the microchannels by using a supply device and introducing gas to be measured; s3: under the preset condition, sequentially and respectively igniting the micro-channel with the smallest size in the plurality of micro-channels with different sizes by utilizing an ignition device according to the size until ignition is successful, wherein the size of the micro-channel before the micro-channel with successful ignition is as follows: the microchannel safety size of the gas to be measured under the predetermined condition.
Preferably, the step S2 includes the following steps, S2-1: the gas to be measured flows from the supply device (20) through the buffer portion of the microchannel arrangement device into the plurality of microchannels.
Preferably, when the temperature in the predetermined condition is higher than room temperature, the temperature of the gas to be measured in the microchannel is brought to the predetermined condition before the step S3 is performed.
Preferably, the step S2 includes the following steps, S2-2: firstly, supplying elemental gases in a plurality of gas supply sources into a mixed gas tank according to the required proportion of the gas to be measured; s2-3: standing the mixed gas tank for a certain period of time; s2-4: and then, introducing the gas to be measured which is uniformly mixed in the mixed gas tank into the micro-channel setting device through a gas supply pipeline.
Preferably, the step S2 includes the steps of, S2-5: before step S2-2 is performed, the plurality of different-sized microchannels, and the gas supply line and the mixture gas tank communicating with the plurality of different-sized microchannels are evacuated.
Preferably, the testing method further comprises performing a preliminary step before step S1, the preliminary step comprising: p1 calibration of the detection unit.
Preferably, the preparing step further comprises: p2: the state of the detection unit is acquired by the control unit so as to respectively judge the states of the microchannel setting device, the supply device and the ignition device.
Preferably, in step S3, controlling one of the ignition electrodes to generate spark by the ignition control portion of the ignition device; when the gas to be measured in the micro-channel where the group of ignition electrodes are located cannot be ignited by the spark, controlling another group of ignition electrodes in the plurality of groups of ignition electrodes to generate the spark through an ignition control part of the ignition device; the micro-channel in which the set of ignition electrodes is located has a size larger than and closest to the previous set, and when a spark ignites the gas to be measured in the micro-channel in which the set of ignition electrodes is located, the size of the micro-channel in front of the set of ignition electrodes in which the spark cannot ignite is: the microchannel safety size of the gas to be measured under the predetermined condition.
Preferably, the state of the detection unit is acquired by the control unit to determine and control the states of the microchannel setting device, the supply device and the ignition device, respectively.
Preferably, a pressure sensor in the detection unit detects a pressure change when the ignition is successful.
Through the technical scheme, the testing method can determine the gas to be measured, the preset conditions and the like according to the characteristics of different processes, particularly the process related to combustible gas, and obtain the safe size of the microchannel of the gas to be measured under the preset conditions, so that the microchannel reactor can obtain the flux as large as possible, the reaction efficiency is high, and the use safety is reliably ensured.
Drawings
FIG. 1 is a schematic block diagram of one embodiment of a test system for testing the safe dimensions of a microchannel according to the invention;
FIG. 2 is a schematic structural diagram of one embodiment of the microchannel arrangement device of the present invention.
Description of the reference numerals
10. A microchannel setting device; 11. a body;
12. a heating section; 13. a microchannel;
14. a buffer section; 15. a bolt fixing hole;
20. a supply device; 21. supplying a gas source;
22. a mixing gas tank; 23. a vacuum pump;
24. a supply main pipe; 25. a mixed gas pipeline;
26. a vacuum supply conduit; 27. an air supply valve;
28. a mixed gas supply valve; 29. a vacuum supply valve;
22a, rupture disk;
30. an ignition device; 31. an ignition electrode;
32. an ignition control section;
40. a detection unit; 41. a pressure sensor;
42. a temperature sensor; 43. pressure sensor of mixed gas tank
50. Control unit
Detailed Description
In the present invention, the use of directional terms such as "upper, lower, left, right" generally means upper, lower, left, right with reference to the accompanying drawings, unless otherwise specified. "inner and outer" refer to the inner and outer contours of the component itself. Further, in the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
The invention provides a test system for testing the safe size of a micro-channel, which comprises: a microchannel arrangement device 10, a supply device 20 and an ignition device 30. The microchannel arrangement device 10 can be provided with a plurality of microchannels 13 of different sizes; a supply device 20 connected to the microchannel arrangement device 10 to supply the gas to be measured to the plurality of microchannels 13 of different sizes; the ignition device 30 is disposed on the microchannel arrangement device 10 and can ignite a plurality of microchannels 13 of different sizes, respectively.
Typically, one end of the microchannel is closed and the other end is capable of communicating with a supply device 20 for introducing the gas to be measured. Of course, it is also possible to close one end with an end piece or the like after the microchannel having both ends open is set in place. The microchannel with both ends open can also be placed in a closed space that can be filled with the gas to be measured.
In addition, ignition typically employs an electric spark as a source of fire, and an electrode for generating the electric spark can be placed in the microchannel through the microchannel so that the source of fire is located in the microchannel. It is of course also possible to provide the end pieces for plugging the microchannels with electrodes which produce electrical sparks.
When the test system is used for testing, the following steps are included.
First, a plurality of microchannels of different sizes are provided in place to allow the passage of the gas to be measured and the ignition of the gas in the plurality of microchannels of different sizes, respectively.
Then, the supply device 20 is used to evacuate the microchannels and introduce the gas to be measured, so that the proportion of the gas to be measured can be reliably ensured and impurities can be prevented from entering.
Then, under a predetermined condition, for example, a room temperature condition, etc., the ignition device 30 is used to sequentially ignite according to the diameter size from the micro-channel with the smallest diameter among the plurality of micro-channels 13 with different sizes until the ignition is successful. The dimensions before the successfully fired microchannel were: the microchannel safety size of the gas to be measured under the predetermined condition.
According to the safe size of the micro-channel measured by the ignition device, the safe critical size of the gas (combustible gas) to be measured in the micro-channel can be tested in situ by the testing system provided by the invention because the safe size is obtained by respectively igniting a plurality of micro-channels 13 with different sizes.
That is, the invention can ensure the limit size range of the gas (combustible gas) to be measured without combustion and explosion when a fire source exists in the microchannel, thereby ensuring that the gas (combustible gas) to be measured cannot be exploded under the safety size of the microchannel. The testing system of the invention can ensure the safe use of the gas to be measured (combustible gas) while ensuring the maximum flux of the micro-channel. By using the testing device of the invention, the safe size of the micro-channel of the gas to be tested under the preset condition can be obtained,
although there is now some controversy over the critical feature size of microchannels, it is generally accepted that channels having a diameter between 0.1 and 2cm are microchannels. It is to be understood that the size of the microchannel that can be set by the microchannel setting device 10 in the present invention is not limited thereto, and the size range can be expanded with the channel processing technology and the research result of the microchannel effect.
As a specific embodiment, the plurality of microchannels of different sizes can be 20, and each two microchannel can be spaced apart by 0.1cm in size. Alternatively, the grouping can be done in order to avoid too large a size gap between the largest and smallest microchannels. For example, 10 of the micro-channel setting device 10 from 0.1 to 1cm are set first and then 10 of the micro-channel setting device from 1.1 to 2.0cm are set. In order to improve the dimensional accuracy, it is also possible to suitably perform the measurement in batches, for example, 10 microchannels with an interval of 0.2 between 0.1 and 2cm are tested to obtain the microchannel safety dimension. Thereafter, based on the safe size of the microchannel, for example, the safe size of the measurement gas under the predetermined condition is 0.5cm, 10 microchannels having an interval of 0.02 between 0.4 and 0.6cm can be tested again, and so on, and the safe limit size of the microchannel can be gradually approached.
The gas to be measured in the present invention refers to the gas which is intended to react in the microreactor, and is generally various combustible gases, including but not limited to hydrogen-oxygen mixture, or propylene, hydrogen and oxygen mixture.
As shown in fig. 1 and 2, in the present invention, a microchannel arrangement device 10 includes: a body 11, a plurality of microchannel setting positions provided on the body 11, and a buffer portion 14. The buffer portion 14 is provided on the body 11 and communicates with a plurality of microchannels 13 of different sizes provided on a plurality of microchannel setting positions.
The microchannel adopted in the invention can be a microchannel made of different materials, and the material, shape, manufacturing method and the like of the microchannel can be selected according to the actual working condition, so that the microchannel arranged in the microchannel arrangement device 10 is close to the actual working condition.
Specifically, the material may be a metal material such as stainless steel, a polymer material such as polymethyl methacrylate, polycarbonate, or polydimethylsiloxane, or an inorganic non-metal material such as glass. The shape of the microchannel can be various such as circular, polygonal, V-shaped, or elliptical in cross section. The microchannel can be manufactured by various methods such as photolithography, etching, hot embossing, softening and stretching.
For example, the body may be a chip and the microchannels may be formed by photolithography, etching, or the like, over a plurality of microchannel settings. The body may be formed as upper and lower dies, and the plurality of microchannel installation sites and the buffer portion 14 may be placed on the dies in advance, and the microchannel tube formed by softening, drawing, or the like may be fixed by the upper and lower dies. Of course, the body may be formed into a plate shape, etc., and the microchannel tube may be provided to the body by bonding, crimping, etc., and similarly, the buffer portion 14 may be prefabricated on the body formed into a plate shape, etc., or may be provided by bonding, crimping, etc.
Specifically, the microchannel arrangement device 10 in a preferred embodiment of the present invention is formed by bonding two chips, and a plurality of microchannels 13 and buffers 14, etc. are engraved on one of the chips, and the other chip is directly covered thereon. The two chips can be connected to each other by a conventional connection method, for example, as shown in the figure, by providing a bolt fixing hole 15 in each chip and connecting the two chips by a bolt.
In the present invention, the microchannels with different sizes mainly refer to the same shape but different diameters, but may also be different shapes according to the testing requirements, but have the same diameter. It will be readily appreciated that when the cross-sectional shape of the microchannel is a shape other than a circle, the diameter can be the diameter of the circumscribed circle of that shape. In addition, the length of the plurality of microchannels of different sizes can be set as appropriate, and the length may be the same or different, and is usually 5 to 20 cm.
The invention makes the gas to be measured flow through the buffer part 14 of the microchannel setting device from the supply device into the microchannels 13 by arranging the buffer part 14 communicated with one side of the microchannels with different sizes and communicating with the supply device 20 by the buffer part 14.
That is, the gas to be measured enters the buffer portion 14 first and then enters each microchannel 13 through the buffer portion 14, so that the gas to be measured can more easily and reliably enter each microchannel 13.
In a preferred embodiment of the present invention, the microchannel arrangement device 10 includes a heating unit 12 capable of heating a plurality of microchannels of different sizes provided at a plurality of microchannel arrangement positions, and the gas to be measured can be heated to a predetermined temperature required by a predetermined condition by the heating unit. That is, when the temperature in the predetermined condition is higher than the room temperature, the temperature of the gas to be measured in the microchannel 13 is brought to the predetermined condition before the ignition by the ignition device 30 is performed.
The heating unit 12 may be any heat generating component in the related art, and for example, a heater composed of stainless steel and a heater rod may be used. The heating section 12 is preferably wrapped around the microchannel arrangement apparatus 10 for uniform heating. In addition, if the predetermined temperature required by the predetermined condition is lower than the room temperature, a cooling device or the like may be provided, which is within the technical idea of the present invention and belongs to a simple modification of the technical solution of the present invention by those skilled in the art.
By arranging the micro-channel setting device 10, the invention can simulate the test under the required working condition, and obtain the safe size of the micro-channel of the gas to be measured under the preset condition.
The supply device 20 of the present invention can supply gas to the microchannel arrangement device 10 independently from each other for a plurality of supply gas sources, and mix them in, for example, the buffer section 14.
In order to more effectively ensure the homogenization of the gas to be measured in each microchannel, it is preferable that the supply means include a plurality of supply gas sources 21, a mixed gas tank 22 communicating with the plurality of supply gas sources 21 to form the gas to be measured, and a gas supply pipe supplying gas from the mixed gas tank 22 to the plurality of microchannels 13 of different sizes.
Firstly, elemental gases in a plurality of gas supply sources 21 are supplied into a mixed gas tank 22 according to the required proportion of the gas to be measured; then the mixed gas tank 22 is kept still for a certain period of time; and then the gas to be measured which is uniformly mixed in the mixed gas tank 22 is introduced into the micro-channel setting device 10 through a gas supply pipeline. The certain period of time can be suitably set according to the properties of the gas to be measured, for example, 5 minutes or the like, to ensure uniform mixing of the gas.
In addition, the supply device 20 preferably further comprises a vacuum pump 23, and the vacuum pump 23 is communicated with the plurality of micro channels with different sizes through vacuum pipelines. Therefore, before the gas to be measured is prepared, the plurality of micro channels 13 with different sizes, the gas supply pipelines communicated with the plurality of micro channels 13 with different sizes and the mixed gas tank 22 are vacuumized, so that the proportion precision of the gas to be measured is further ensured, and impurities are prevented from being doped.
Further, the hybrid tank 22 is provided with a rupture disk 22a to prevent an excessive pressure in the hybrid tank 22, and the rupture disk 22a can rupture to release the pressure when the pressure of the hybrid gas in the hybrid tank 22 reaches a set pressure.
Specifically, as a preferred embodiment, as shown in fig. 1, a plurality of supply gas sources 21 and a plurality of mixture gas tanks 22 are respectively connected through gas source supply pipes 26, the gas supply pipes include a supply main pipe 24 connected to the microchannel setting device 10 and a mixture gas pipe 25 connected to the mixture gas tank 22, the vacuum pipes include a supply main pipe 24 connected to the microchannel setting device 10 and a vacuum supply pipe 26 connected to a vacuum pump 23, and the supply main pipe 24, the mixture gas pipe 25 and the vacuum supply pipe 26 are communicated.
Because gas mixture pipeline 25, vacuum supply pipeline 26 all communicate with supply main pipe 24, no matter to the microchannel evacuation or let in pending gas, all only need through supplying the interface between main pipe 24 and microchannel setting device 10, therefore can simplify sealedly, improve test efficiency, reduce test cost to a certain extent. As to how the microchannel arrangement device 10 is sealed and the interface between the supply header 24 and the microchannel arrangement device 10 is sealed, various means for sealing the conduits, such as sealing sheets, can be used, and will not be described herein.
In addition to the above-mentioned technical solution, in order to control the gas supply from the supply device 20 to the microchannel arrangement device 10, the gas supply lines 26 are respectively provided with gas supply valves 27, and the gas mixture line 25 and the vacuum supply line 26 are respectively provided with a gas mixture supply valve 28 and a vacuum supply valve 29. Further, a flowmeter or the like may be provided in the pipe as necessary. In addition, the mixture supply valve 28 is placed close to the microchannel setting device 10, so that the gas in the microchannel is prevented from being ignited and spread to 14 and then spread along the pipeline 24 during experimental test.
In the test system according to the preferred embodiment of the present invention, when step S2 is performed, the air supply valve 27 is first closed, the mixture air supply valve 28 and the vacuum supply valve 29 are opened, and then the vacuum pump 23 is opened to evacuate the mixture air tank 22 and the microchannel setting device 10.
When the mixed gas tank 22 and the microchannel setting device 10 reach a predetermined vacuum degree, the vacuum pump 23 is turned off, the vacuum supply valve 29 is closed, and the mixed gas supply valve 28 is closed. After the gas supply valve 27 is opened and a predetermined amount of the simple substance gas is supplied to the mixing gas tank 22, the gas supply valve 27 is closed. After the mixture gas tank 22 is uniformly mixed, the gas to be measured is formed, and the gas to be measured is introduced into the microchannel setting device 10 by opening the gas mixture supply valve 28. When the pressure required for the test is reached, the mixture supply valve 28 is closed.
The ignition device 30 of the present invention can be used in a variety of devices that provide a source of ignition for the microchannels, preferably using an ignition electrode having a relatively small diameter. Specifically, in the present invention, the ignition device includes a plurality of sets of ignition electrodes 31, the plurality of sets of ignition electrodes 31 being respectively disposed in the plurality of microchannels of different sizes, and an ignition control device 32 capable of driving the plurality of sets of ignition electrodes 31 to be respectively ignited.
Specifically, since the ignition electrode 31 is extremely fine, direct ignition can be easily performed through the tube wall of the microchannel into the microchannel 13. Only firing electrode 31 disposed in the largest-sized microchannel and firing electrode 31 disposed in the smallest-sized microchannel are shown in fig. 1. Specifically, the ignition electrode 31 is formed by two electrode ends arranged with a small gap therebetween, one being a center electrode and the other being a ground electrode, and when ignition is performed, high voltage electricity enters the ground electrode through the small gap to burst a spark, thereby performing ignition. In a preferred embodiment of the present invention, the ignition electrode 31 is provided on the peripheral wall of the microchannel, further preferably at an intermediate position in the longitudinal direction of the microchannel.
The ignition control device 32 can be an ignition button that is manually controlled, or can be electrically connected to the control unit 50 for ignition.
In the test method using the device, one of the ignition electrodes 31 in the plurality of groups is controlled by the ignition control part 32 of the ignition device 30 to generate sparks; when the spark cannot ignite the gas to be measured in the micro-channel where the group of ignition electrodes are located, controlling another group of ignition electrodes in the plurality of groups of ignition electrodes 31 to generate sparks through the ignition control part 32 of the ignition device 30; the micro-channel in which the set of ignition electrodes is located has a size larger than and closest to the previous set, and when a spark ignites the gas to be measured in the micro-channel in which the set of ignition electrodes is located, the size of the micro-channel in front of the set of ignition electrodes in which the spark cannot ignite is: the microchannel safety size of the gas to be measured under the predetermined condition.
The test system according to the invention comprises a control unit 50 and a detection unit 40 capable of detecting a change of state in the microchannel. The control unit 50 is electrically connected to the supply device 20, the ignition device 30, and the detection unit 40. In the test method using this apparatus, the control unit 50 can acquire the state of the detection unit 40 to determine and control the states of the microchannel arrangement device 10, the supply device 20, and the ignition device 30, respectively, and thus the test can be performed easily and accurately.
Wherein the control unit can be a computer and software such as temperature remote transmission, pressure remote transmission, etc. capable of operating in the computer to obtain the states of the microchannel setting device 10 and the supply device 20 detected by the detection unit 40.
The detection unit 40 can be provided in various kinds as needed, for example, an optical sensor, a temperature sensor, and the like. Specifically, when the heating part 12 is provided on the microchannel arrangement device 10, it is preferable that the detection unit includes a temperature sensor 42 to detect whether the gas to be measured reaches a predetermined condition. Further, an optical sensor capable of detecting a spark in the microchannel may be provided on the buffer portion 14 side.
As a preferred embodiment of the present invention, it is preferable that the detection unit 40 includes a pressure sensor 41, and the pressure sensor 41 is provided in the microchannel arrangement device 10 at a position communicating with each of the plurality of microchannels 13 having different sizes, that is, the buffer portion 14. With this arrangement, when the ignition is successful, the pressure sensor 41 in the detection unit 40 can detect the pressure change.
In addition, when the test system according to the preferred embodiment of the present invention is used, the calibration of the detection unit 40 is performed before the start of the test. That is, the temperature sensor 42, the pressure sensor 41, and the hybrid tank pressure sensor 43 elements are calibrated to ensure that the operating state of the detection unit 40 is normal.
Further, the state of the detection unit 40 can be acquired by the control unit 50 to determine and control the states of the microchannel arrangement device 10, the supply device 20, and the ignition device 30, respectively. For example, a non-combustible inert gas can be included in the supply gas source 21 to pass into the microchannel setting device 10, the supply device 20, and the status of the pressure sensor 41, and the mixed gas tank pressure sensor 43 is used to confirm the line connection. For example, the gas in the microchannel installation device 10 is heated by the heating unit 12, and the system state is further confirmed by the states of the pressure sensor 41 and the temperature sensor 42. Therefore, the test system can effectively confirm whether the test system is normal or not by using the temperature and the pressure collected by the detection unit.
In addition, when the test system is used for implementing the test method, in order to ensure safety, a safety protection baffle is preferably arranged outside the test system, so that the operator is prevented from being injured when an accident occurs.
As can be seen from the above description, the present invention provides a test system capable of in situ testing the safety critical dimension of a gas to be measured (combustible gas) within a microchannel. By utilizing the test system, the gas to be measured, the preset conditions and the like can be determined according to the characteristics of different processes, particularly the process related to combustible gas, the maximum micro-channel safety size of the gas to be measured under the preset conditions is obtained, and the intrinsic safety of the micro-channel is exerted. The testing method using the system is simple and reliable, the actual working condition can be simulated, and the acquired experimental values can directly guide the design of the micro-channel.
The present invention will be described in detail below by way of examples.
(Synthesis of propylene oxide)
The propylene oxide is the third largest propylene derivative, is mainly used for producing polyether polyol, propylene glycol, various nonionic surfactants and the like, and is an important chemical raw material. The conventional processes for synthesizing propylene oxide mainly include Chlorohydrin process, isobutane co-oxidation process (PO/TBA process), ethylbenzene co-oxidation process (PO/SMprocess), and cumene oxidation process (CHP process).
However, the above process produces many wastes and by-products, which cause serious environmental pollution and poor atomic economy. In new processes which continuously appear due to the market demand of propylene oxide, a molecular oxygen direct propylene oxidation method is a research focus because the process is clean and the flow is relatively simple. In order to ensure safety, experiments are often carried out outside the explosion limit range of mixed gas or at lower concentration, so that the reaction rate is limited, the reaction balance is influenced, and the economic pressure brought by nitrogen circulation is increased.
The testing system for testing the safe size of the micro-channel can obtain the safe size of the micro-channel under the reaction conditions of propylene, hydrogen and oxygen, so that the micro-channel can obtain the flux as large as possible and the use safety of the gas to be tested can be reliably ensured.
Example 1
Propylene oxide is directly synthesized in a propylene, hydrogen and oxygen microreactor.
The mixing ratio of the propylene to the hydrogen to the oxygen is 1:1: 1.
Reaction conditions are as follows: normal pressure, 140 ℃.
Microchannel in reactor: the material is 316 stainless steel, and the cross section of the channel is circular. The sizes (diameters) are respectively 0.1cm, 0.2cm, 0.3cm, 0.4cm, 0.5cm and 0.6 cm.
As shown in FIG. 1, the microchannel arrangement device 10 of the embodiment is provided with a heating part 14 because the reaction temperature is higher than the room temperature.
The test system of the invention is used for carrying out the following test methods:
1) turning on the control unit 50, namely turning on the computer control system, and turning on the pressure sensor control software and the temperature control software;
2) closing the air supply valve 27, opening the vacuum supply valve 29, opening the mixed gas supply valve 28, opening the vacuum pump 23 to vacuumize the pressure of the test system, closing the vacuum pump 23, and closing the mixed gas supply valve 28 and the vacuum supply valve 29;
3) the gas supply valve 27 is opened to prepare a 1:1:1 mixture of propylene, hydrogen and oxygen, and when the pressure detected by the mixed gas tank pressure sensor 43 reaches 300psi, the gas supply valve 27 is closed. Standing for 5 minutes to ensure that the gas is uniformly mixed;
4) opening a heating system, and setting the heating temperature to be 140 ℃;
5) opening the mixture supply valve 28, slowly introducing the mixture in the mixture tank 22 into the microchannel setting device 10 until the pressure detected by the pressure sensor 41 reaches 145psi, and closing the mixture supply valve 28;
6) under the condition that the protective baffle is ensured to cover the test system, an ignition electrode of a micro-channel with the size of 0.1cm is switched on for ignition, and the numerical value change of the pressure sensor 41 is observed;
7) if the value of the pressure sensor 41 has a sudden change, the ignition is successful.
8) If the ignition is unsuccessful, an ignition electrode of a micro-channel with the size of 0.2cm is switched on for ignition. And so on until the ignition is successful.
9) Under this condition, the size of the safe channel of the mixed combustible gas is the size of the micro-channel which has failed in the last ignition.
(Synthesis of Hydrogen peroxide solution)
The prior hydrogen peroxide mainly adopts an anthraquinone method and has the defects of large amount and serious pollution. The hydrogen and oxygen are directly synthesized into hydrogen peroxide, so that the method has the advantages of environmental protection and high atom utilization rate, and is always a hotspot of research. However, hydrogen is flammable and explosive gas, the explosion limit is extremely wide, and the current research is related to a method of diluting by using a large amount of nitrogen. Because of small size and large specific surface area of the microreactor, free radicals generated by reaction are quenched in continuous collision with a pipe wall, and flame is difficult to propagate. Therefore, the concentration of hydrogen and oxygen is not limited by explosion limit during reaction in the microreactor, the reaction speed is directly improved, and the high-pressure condition for improving the concentration of hydrogen is avoided, so that the method is a new technology for preparing hydrogen peroxide by directly combining hydrogen and oxygen.
The testing system for testing the safe size of the micro-channel can obtain the safe size of the micro-channel under the reaction of the hydrogen and the oxygen, so that the micro-channel can obtain the flux as large as possible and the use safety of the gas to be tested can be reliably ensured.
Example 2
Hydrogen peroxide is directly synthesized by hydrogen and oxygen.
The mixing ratio of hydrogen to oxygen is 1: 1.
Reaction conditions are as follows: 0.2MPa and normal temperature.
Microchannel in microreactor: the material is polymethyl methacrylate, and the cross section of the channel is circular. The sizes (diameters) are respectively 0.1cm, 0.2cm, 0.3cm, 0.4cm, 0.5cm and 0.6 cm.
Since the reaction temperature is normal temperature when the test system is connected as shown in FIG. 1, the microchannel arrangement device 10 in the embodiment may not be provided with the heating unit 14.
The test system of the invention is used for carrying out the following test methods:
1) turning on the control unit 50, namely turning on the computer control system, and turning on the pressure sensor control software and the temperature control software;
2) closing the air supply valve 27, opening the vacuum supply valve 29, opening the mixed gas supply valve 28, opening the vacuum pump 23 to vacuumize the pressure of the test system, closing the vacuum pump 23, and closing the mixed gas supply valve 28 and the vacuum supply valve 29;
3) the gas supply valve 27 was opened to prepare a 1:1 mixture of hydrogen and oxygen. When the pressure detected by the mixture tank pressure sensor 43 reaches 600psi, the air supply valve 27 is closed. Standing for 5 minutes to ensure that the gas is uniformly mixed;
4) opening the mixture supply valve 28, slowly introducing the mixture in the mixture tank 22 into the microchannel setting device 10 until the pressure detected by the pressure sensor 41 reaches 435psi, and closing the mixture supply valve 28;
5) under the condition that the protective baffle is ensured to cover the test system, an ignition electrode of a micro-channel with the size of 0.1cm is switched on for ignition, and the numerical value change of the pressure sensor 41 is observed;
6) if the value of the pressure sensor 41 has a sudden change, the ignition is successful.
7) If the ignition is unsuccessful, an ignition electrode of a micro-channel with the size of 0.2cm is switched on for ignition. And so on until the ignition is successful.
8) Under this condition, the size of the safe channel of the mixed combustible gas is the size of the micro-channel which has failed in the last ignition.
Through the embodiments 1 and 2, the test system can determine the gas to be measured, the preset conditions and the like according to the characteristics of different processes, particularly the process related to combustible gas, obtain the safe size of the micro-channel of the gas to be measured under the preset conditions, and exert the intrinsic safety of the micro-channel. The testing method using the testing system is simple and reliable, can simulate the actual working condition, and the obtained experimental value can directly guide the design of the microchannel, so that the microchannel reactor can obtain the flux as much as possible, the reaction efficiency is high, and the use safety is reliably ensured.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (10)
1. A test method for testing the safety size of a microchannel is characterized by comprising the following steps,
s1: -arranging a plurality of microchannels (13) of different sizes on a microchannel arrangement means (10);
s2: pumping a plurality of microchannels (13) into vacuum by using a supply device (20) and then introducing gas to be measured;
s3: under the preset condition, the micro-channel with the smallest size in the plurality of micro-channels (13) with different sizes is ignited by the ignition device (30) in turn according to the size until the ignition is successful,
the dimensions of the microchannel before the successfully fired microchannel were: the microchannel safety size of the gas to be measured under the predetermined condition.
2. The test method according to claim 1, wherein the step S2 includes the steps of, S2-1: the gas to be measured flows from the supply device (20) through the buffer portion (14) of the microchannel arrangement device (10) into the plurality of microchannels (13).
3. The test method according to claim 1, wherein when the temperature in the predetermined condition is higher than room temperature, the temperature of the gas to be measured in the microchannel (13) is brought to the predetermined condition before performing step S3.
4. The test method according to claim 1, wherein the step S2 includes the steps of, S2-2: firstly, elemental gases in a plurality of gas supply sources (21) are supplied into a mixed gas tank (22) according to the required proportion of the gas to be measured;
s2-3: then the mixed gas tank (22) is kept still for a certain period of time;
s2-4: and then the gas to be measured which is uniformly mixed in the mixed gas tank (22) is introduced into the micro-channel setting device (10) through a gas supply pipeline.
5. The test method according to claim 4, wherein the step S2 includes the steps of, S2-5: before step S2-2 is performed, the plurality of different-sized microchannels (13), and the gas supply line and the mixture gas tank (22) communicating with the plurality of different-sized microchannels (13) are evacuated.
6. The test method of claim 1, further comprising performing a preliminary step before step S1, the preliminary step comprising: p1 calibration of the detection unit (40).
7. The test method of claim 6, wherein the preparing step further comprises: p2: the state of the detection unit (40) is acquired by a control unit (50) to respectively determine the states of the microchannel setting device (10), the supply device (20) and the ignition device (30).
8. The test method according to claim 1, wherein, in step S3,
controlling one of the ignition electrodes (31) to generate a spark by an ignition control part (32) of the ignition device (30);
when the gas to be measured in the micro-channel where the group of ignition electrodes are positioned cannot be ignited by the spark, controlling another group of ignition electrodes in the plurality of groups of ignition electrodes (31) to generate the spark through an ignition control part (32) of the ignition device (30); the micro-channel in which the set of ignition electrodes is located is larger in size than the preceding set, and is closest to the preceding set,
when a spark ignites the gas to be measured in the microchannel in which the set of ignition electrodes is located, the dimensions of the microchannel before the set of ignition electrodes where the spark cannot ignite are: the microchannel safety size of the gas to be measured under the predetermined condition.
9. The testing method according to any one of claims 1 to 8, characterized in that the state of the detection unit (40) is acquired by a control unit (50) to determine and control the state of the microchannel arrangement device (10), the supply device (20), the ignition device (30), respectively.
10. A test method according to claim 9, characterized in that a pressure sensor (41) in the detection unit (40) detects a pressure change when the ignition is successful.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005338094A (en) * | 2004-05-27 | 2005-12-08 | Asml Holding Nv | Gas gauge proximity sensor and measurement method |
| CN202870017U (en) * | 2012-10-25 | 2013-04-10 | 四川威特龙消防设备有限公司 | Oil-gas explosion critical parameter testing device |
| CN106441909A (en) * | 2016-09-20 | 2017-02-22 | 哈尔滨工程大学 | Constant volume bomb combustion gas mixing system and control method |
| CN106568887A (en) * | 2016-10-14 | 2017-04-19 | 中国科学院合肥物质科学研究院 | Experimental device for research on hydrogen combustion in nuclear power plant containment shell |
| CN106872664A (en) * | 2017-04-17 | 2017-06-20 | 中国石油化工股份有限公司 | The method of testing of the critical propagation diameter of fuel gas |
| CN107064411A (en) * | 2017-04-14 | 2017-08-18 | 中国石油化工股份有限公司 | The method for measuring mixed gas quenching diameter |
-
2018
- 2018-11-08 CN CN201811326845.4A patent/CN111156933B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005338094A (en) * | 2004-05-27 | 2005-12-08 | Asml Holding Nv | Gas gauge proximity sensor and measurement method |
| CN202870017U (en) * | 2012-10-25 | 2013-04-10 | 四川威特龙消防设备有限公司 | Oil-gas explosion critical parameter testing device |
| CN106441909A (en) * | 2016-09-20 | 2017-02-22 | 哈尔滨工程大学 | Constant volume bomb combustion gas mixing system and control method |
| CN106568887A (en) * | 2016-10-14 | 2017-04-19 | 中国科学院合肥物质科学研究院 | Experimental device for research on hydrogen combustion in nuclear power plant containment shell |
| CN107064411A (en) * | 2017-04-14 | 2017-08-18 | 中国石油化工股份有限公司 | The method for measuring mixed gas quenching diameter |
| CN106872664A (en) * | 2017-04-17 | 2017-06-20 | 中国石油化工股份有限公司 | The method of testing of the critical propagation diameter of fuel gas |
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