A rotary valve for gas sampling

Abstract

The present invention provides a rotary valve for gas sampling. The present invention includes: a valve body, a motor, a motor support frame and a main frame with a gas passage. One end of the valve body is connected to the motor, and the other end extends into the main frame, and the end matches the through hole provided in the main frame. The motor is detachably connected to the motor support frame, and the motor support frame is fixedly connected to the main frame. The valve body includes a first steering valve, on which a through hole is provided, and the diameter of the through hole matches the diameter of the gas passage. The first steering valve is provided with an exhaust gas outlet surface, and the surface does not intersect with any point on the through hole of the first steering valve. The present invention drives the first steering valve to rotate at an angle by a motor, so as to control the collected gas to enter the exhaust gas pipeline or the collection pipeline. Compared with the existing solenoid valve control, the present invention is light in overall weight, sufficiently miniaturized and modularized, and is suitable for wide promotion in the field of gas sampling technology.

Description

Technical Field

[0001] The invention relates to the technical field of gas detection, and in particular to a rotary valve for gas sampling. Background Art

[0002] Gas sampling technology collects gas through a gas sampling device. After the gas is collected into a fixed container, the components and unknown substances in the gas are determined by the detection instrument. The reasonable collection of samples is very important for the entire inspection process, which directly affects the accuracy of the final analysis results.

[0003] Whether it is the collection of industrial gas samples such as chemical waste gas or the collection of human respiratory gas, since in some experiments, not all gas samples are collected, there may be some waste gas irrelevant to the detection, which needs to be excluded. Taking human exhaled breath as an example, human respiratory gas, as a reflection of physical health, can reflect some important pathological symptoms, so human exhaled breath can be used for various medical diagnostic techniques including exhaled breath analysis. Exhaled gas is mainly composed of two parts, one is the "dead space gas" from the upper respiratory tract that has not exchanged gas with blood, and the other is the gas from the deep alveoli that has exchanged gas with blood, called "alveolar gas", about 150ml. The main object of respiratory gas research is alveolar gas. Dead space gas will dilute the concentration of disease markers in alveolar gas and affect the effectiveness of respiratory gas analysis.

[0004] The collection devices in the prior art all have certain defects to a greater or lesser extent. For example, CN205228882U "A device for sampling end-of-tidal air" ensures the quantitative collection of the collected gas through the cooperation of two-way valve one and two-way valve two. The "A breath analysis device and its use method" with announcement number CN110226931A adopts multiple valve controls including "three-way valve", "first valve" and "second valve". The solenoid valve with a larger flow rate generates more heat and has a large overall weight, which is inconvenient to carry and is not lightweight or miniaturized enough. At the same time, a large number of valves also means that there is more gas residue from the subject in the valve body, which will also lead to inaccurate collection data for the next subject. Summary of the invention

[0005] According to the technical problem raised above, a rotary valve for gas sampling is provided. The invention mainly has high integration and effectively reduces the overall weight of the device. The technical means adopted by the invention are as follows:

[0006] A rotary valve for gas sampling comprises: a valve body, a motor, a motor support frame and a main frame with a gas passage, one end of the valve body is connected to the motor, and the other end extends into the main frame, and the end matches the through hole provided in the main frame, the motor is detachably connected to the motor support frame, and the motor support frame is fixedly connected to the main frame, the valve body comprises a first steering valve, a through hole passing through the first steering valve is provided, and the diameter of the through hole matches the diameter of the gas passage, the first steering valve is provided with at least one exhaust gas outlet surface, and the exhaust gas outlet surface does not intersect with any point on the through hole of the first steering valve.

[0007] Furthermore, the first steering valve is in the shape of a cylinder cut longitudinally by a plane.

[0008] Furthermore, it also includes a second steering valve, the first steering valve is close to the air inlet side of the gas passage, the second steering valve is close to the air outlet side of the gas passage, the second steering valve has a through hole passing through it at a position corresponding to the first steering valve, and the main body shape of the second steering valve is a cylinder.

[0009] Furthermore, a positioning hole is provided at one end of the first steering valve extending into the main frame, and a detection mechanism is also included. The main frame has a groove for accommodating the detection mechanism. The detection mechanism is used to emit light under the control of an external electronic control device, and identify the rotation state of the first steering valve based on the state of the light penetrating the positioning hole.

[0010] Furthermore, the positioning hole of the first steering valve includes an air path positioning hole and an angle positioning hole. The air path positioning hole and the through hole of the first steering valve are perpendicular to each other in space. The air path positioning hole passes through its cutting surface and is at a certain distance from the air path channel of the first steering valve. There is a preset angle between the angle positioning hole and the air path positioning hole.

[0011] Furthermore, a positioning hole is provided at one end of the second steering valve extending into the main frame. The second detection mechanism emits light under the control of an external electronic control device, and identifies the rotation state of the second steering valve based on the state of the light penetrating the positioning hole. The positioning hole of the second steering valve and the through hole of the second steering valve are perpendicular to each other in space.

[0012] Furthermore, a slot hole is provided on one side of the valve body connected to the motor, and a rotating shaft is embedded therein. The outer diameter of the rotating shaft matches the inner diameter of the slot hole of the valve body, and the rotating shaft is connected to the motor.

[0013] Furthermore, the rotating shaft and the valve body are made of the same or different materials, and the valve body and the main frame are made of the same or different materials. When they are the same, they are both made of rigid materials; when they are different, the valve body is made of flexible materials, and the rotating shaft and the main frame are made of rigid materials.

[0014] The present invention drives the first steering valve to rotate at an angle by a motor, thereby controlling the collected gas to enter an exhaust gas pipe or a collection pipe. Compared with the existing solenoid valve control, the present invention is light in overall weight, sufficiently miniaturized and modularized, and is suitable for wide promotion in the field of gas sampling technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a schematic diagram of the main structure of the present invention.

[0017] Figure 2 It is an exploded view of the present invention.

[0018] Figure 3 It is a schematic diagram of the structure of the present invention applied to an exhaled breath collection device.

[0019] Figure 4 The present invention is a circuit diagram of an exhaled breath collection device.

[0020] In the figure: 103, exhaled air inlet; 104, mouthpiece; 201, CO2 sensor; 202, flow / flow velocity sensor; 3, rotary valve; 301, photoelectric coupler; 302, first steering valve; 303, main frame; 304, first motor; 305, motor support frame; 306, assembly nut; 401, sampler self-locking joint; 501, micro air pump; 502, back-blowing mechanism filter; 503, trachea connecting joint. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] like Figure 1 , 2As shown, this embodiment discloses a rotary valve 3 for gas sampling, including: a valve body, a motor, a motor support frame and a main frame 303 with a gas passage, one end of the valve body is connected to the first motor 304, and the other end extends into the main frame, which end matches the through hole opened in the main frame, the first motor is detachably connected to the motor support frame 305, and the motor support frame is fixedly connected to the main frame by an assembly nut 306, the valve body includes a first steering valve 302, a through hole is opened thereon, the diameter of the through hole matches the diameter of the gas passage, the first steering valve is opened with at least one exhaust gas outlet surface, and the exhaust gas outlet surface does not intersect with any point on the through hole of the first steering valve. The shape of the first steering valve is a cylinder cut longitudinally by a plane, and the plane is the exhaust gas outlet surface, and the exhaust gas outlet surface can also be other feasible shapes.

[0023] A positioning hole is provided at one end of the first steering valve extending into the main frame, and the first steering valve also includes a detection mechanism. The main frame includes a groove for accommodating the detection mechanism. The detection mechanism is used to emit light under the control of an external electronic control device, and to identify the rotation state of the first steering valve based on the state of the light penetrating the positioning hole. In this embodiment, the detection mechanism uses a photoelectric coupler 301.

[0024] In an optional embodiment, the exhaust gas outlet surface is one or two. If there are two, the two cutting planes are symmetrically arranged about the longitudinal section of the cylinder through the center of the circle, that is, they are oblong. If it is cut by two planes, there can be one positioning hole. If it is cut by one plane, there are at least two positioning holes. The second positioning hole and the first positioning hole are on the same plane and have a preset angle. In other optional embodiments, there can be more positioning holes, and the positioning is more accurate, such as the third positioning hole. The third positioning hole is perpendicular to the first positioning hole in space, and the second positioning hole is at a different distance from the two, that is, the second positioning hole is arranged on the side close to the cutting surface or on the cylindrical body close to the non-cutting surface.

[0025] According to different usage conditions, it can be divided into the following two achievable structural forms, wherein the A-type rotary valve part includes a rigid main body and a valve body that can rotate in the main body, the main body is provided with a longitudinal gas passage, the bottom of the longitudinal gas passage is the gas collection mechanism, the valve body includes a first steering valve, the sampler self-locking connector 401 connected to the bottom of the rotary valve can be a quick connector, one end of the first steering valve is connected to the first motor, and the other side is provided with a positioning hole. The positioning hole of the first steering valve includes an air path positioning hole and an angle positioning hole, the air path positioning hole and the through hole of the first steering valve are perpendicular to each other in space, the air path positioning hole passes through its cutting surface and is at a certain distance from the air path channel of the first steering valve, and there is a preset angle between the angle positioning hole and the air path positioning hole. In the meantime, the following B-type back-blowing gas passage can also be set.

[0026] The B-type rotary valve part includes a rigid main body and a valve body that can rotate in the main body. The main body is provided with a longitudinal gas passage and a transverse back-blowing gas passage. The back-blowing gas passage is connected to the longitudinal gas passage. The bottom of the longitudinal gas passage is a gas collection mechanism. In this embodiment, when collecting the exhaled air of the subject, the gas collection mechanism is connected to a detachable sampling bag to facilitate the subsequent analysis of the sampled gas in the sampling bag. The valve body includes a first steering valve and a second steering valve, wherein the first steering valve is arranged between the upper longitudinal gas passage and the back-blowing gas passage, and the second steering valve is arranged between the back-blowing gas passage and the lower longitudinal gas passage. One end of the first steering valve is connected to the first motor, and one end of the second steering valve is connected to the second motor.

[0027] A through hole is provided at the position of the second steering valve corresponding to the first steering valve, and the main body of the second steering valve is in the shape of a cylinder. A positioning hole is provided at one end of the second steering valve extending into the main frame. The second detection mechanism emits light under the control of the external electric control device, and identifies the rotation state of the second steering valve based on the state of the light penetrating the positioning hole. The positioning hole of the second steering valve and the through hole of the second steering valve are perpendicular to each other in space. In order to facilitate fine adjustment of the rotation angle of the rotary valve body, the motor driving the steering valve in this embodiment uses a gear reduction motor, and the specific reduction ratio can be selected according to actual conditions. For example, two models of 1:380 and 1:1000 are selected in this embodiment.

[0028] The material of the rotary valve body is the same as or different from that of the main body. If they are different, the main body can be made of PK material (polyketone) as a supporting stator, and the rotary valve body can be made of plastic material as a rotor. The side connected to the motor is inlaid with a metal shaft, and the outer diameter of the shaft matches the inner diameter of the slot of the plastic valve body. In this embodiment, copper is used as the rotor. The metal shaft can effectively prevent the motor's lubricating oil from flowing into the gas passage while ensuring sufficient rigidity. If they are the same, other feasible materials including ceramics can be selected.

[0029] like Figure 3 , Figure 4 As shown, taking the present invention applied in an exhaled gas collection device as an example, the overall sampling process is explained, wherein the exhaled gas collection device includes a gas detection mechanism and a main processor, the rotary valve 3 provided by the present invention is installed between the gas detection mechanism and the gas collection mechanism, the gas detection mechanism includes a CO2 sensor 201 and / or a flow sensor 202, the subject installs the mouthpiece 104 and exhales into the device, the exhaled gas enters from the exhaled gas inlet 103, after passing through the CO2 sensor and / or the flow sensor, the main processor determines whether the exhaled gas is dead space gas or alveolar gas according to a preset standard, if it is dead space gas, it flows out of the device along the gas passage and the plane of the first steering valve; if it is alveolar gas, the main processor controls the first rotary valve to rotate to form a passage for gas collection.

[0030] Specifically, in this embodiment, the processor can use an STM32 embedded low-power chip based on the ARM core, and the carbon dioxide sensor uses the principle of non-dispersive infrared, and the models are C500 and C600. In the above steps, there are multiple ways to determine the collection:

[0031] a) When the carbon dioxide concentration is higher than the specified threshold, the rotary valve rotates to realize the exhaled breath collection. The concentration threshold can be set to 2%.

[0032] b) Use the flow sensor to integrate time and flow rate to collect flow. Set the evacuated gas flow volume to 500mL-1000mL

[0033] c) The flow rate and carbon dioxide concentration are dual indicators to determine the rotation of the rotary valve at the same time. That is, when the flow rate is within the range of 3L / min-4L / min and the carbon dioxide concentration is higher than 2%, the rotary valve selection is executed. And the collection program is executed.

[0034] In order to prevent the residual gas in the gas channel from interfering with the next subject, the exhaled gas collection device also includes a back-blowing mechanism. At this time, the main frame is provided with a back-blowing pipeline, and the first steering valve is arranged between the upper longitudinal gas passage and the back-blowing gas passage; the second steering valve of the B scheme is arranged between the back-blowing gas passage and the lower longitudinal gas passage, and the back-blowing mechanism includes a micro air pump 501, and the exhaust port of the micro air pump is connected to the back-blowing gas passage through a trachea connecting joint 503, and a back-blowing mechanism filter 502 for purifying air can also be installed therebetween. Before the next subject exhales, the micro air pump is turned on, the gas path of the first rotary valve is longitudinal, and the gas path of the second rotary valve of the B scheme is transverse, so as to quickly remove the residue in the gas channel.

[0035] The specific use of Example 1 of the present invention applied in the exhaled gas collection device includes the following steps: Step 1. Before using the device, first reset the device through the LED screen, that is, the flat side of the first rotary valve is facing up, the micro air pump of the back-blowing mechanism is turned off, and other electrical components are in standby mode. Step 2. Under the detection of the CO2 sensor and / or the flow sensor, it is detected that the exhaled gas is dead space gas or alveolar gas. If it is dead space gas, it flows out of the device along the gas passage and the plane of the first steering valve; if it is alveolar gas, the main processor controls the first rotary valve to form a passage for gas collection. Step 3. Remove the gas collection bag, and before the next subject exhales, turn on the micro air pump, the gas path of the first rotary valve is longitudinal, and the quick connector is used as a plug to remove the residual gas in the gas path.

[0036] The specific use of Example 2 of the present invention applied in the exhaled gas collection device includes the following steps: Step 1. Before using the device, first reset the device through the LED screen, that is, the flat side of the first rotary valve is facing upward, the air hole of the second rotary valve is in a longitudinal (or transverse) state, the micro air pump of the back-blowing mechanism is turned off, and other electrical components are in standby state. Step 2. Under the detection of the CO2 sensor and / or the flow sensor, it is detected that the exhaled gas is dead space gas or alveolar gas. If it is dead space gas, it flows out of the device along the gas passage and the plane of the first steering valve; if it is alveolar gas, the main processor controls the formation of a passage between the first rotary valve and the second rotary valve to collect gas. Step 3. Before the next subject exhales, turn on the micro air pump, the gas path of the first rotary valve is longitudinal, and the gas path of the second rotary valve is transverse, to remove the residual gas in the gas path.

[0037] During this process, the specific postures of the first rotary valve and the second rotary valve are detected by the photoelectric coupler. Specifically, the rotary valve rotates slowly driven by the motor. When the photoelectric coupler detects the light path, it proves that the first rotary valve is in the horizontal position of the through hole. The rotary valve continues to rotate. If the light path is detected again within the preset time, it proves that the angle positioning hole has been passed. Therefore, it is judged whether the horizontal position of the through hole that the rotary valve was in before was cylindrical upward or flat upward, thereby determining the posture of the first rotary valve.

[0038] The method of stopping collection also includes different schemes, specifically,

[0039] After executing the collection procedure, the rotary valve is turned on, and the exhaled air will flow into the exhaled air sampling bag through the rotary valve.

[0040] At this time, the flow rate sensor is used to determine the flow rate. It is determined based on the volume of the air bag. Usually, the air bag volume is selected to be 2L, and the sampling air bag is filled with a volume of 1L.

[0041] Using the flow sensor, after entering the collection mode, when the gas volume exceeds 1L, the rotary valve rotates. At this time, it is non-collection mode. Exhaled air cannot be filled into the air bag.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rotary valve for gas sampling, characterized in that: include: A valve body, a motor, a motor support frame and a main frame with a gas passage, one end of the valve body is connected to the motor, and the other end extends into the main frame, and the end matches the through hole provided in the main frame, the motor is detachably connected to the motor support frame, and the motor support frame is fixedly connected to the main frame, the valve body includes a first steering valve, a through hole is provided on the first steering valve, and the diameter of the through hole matches the diameter of the gas passage, and the first steering valve is provided with at least one exhaust gas outlet surface, and the exhaust gas outlet surface does not intersect any point on the through hole of the first steering valve; The first steering valve is in the shape of a cylinder cut longitudinally by a plane; It also includes a second steering valve, wherein the first steering valve is close to the gas inlet side of the gas passage, and the second steering valve is close to the gas outlet side of the gas passage, and the second steering valve has a through hole extending therethrough at a position corresponding to the first steering valve, and the main body of the second steering valve is cylindrical; At least one positioning hole is formed at one end of the first steering valve extending into the main frame, and the first steering valve also includes a detection mechanism. The main frame includes a groove for accommodating the detection mechanism. The detection mechanism is used to emit light under the control of an external electronic control device, and identify the rotation state of the first steering valve based on the state of the light penetrating the positioning hole.

2. The gas sampling rotary valve according to claim 1, characterized in that: The positioning hole of the first steering valve includes an air path positioning hole and an angle positioning hole. The air path positioning hole and the through hole of the first steering valve are perpendicular to each other in space. The air path positioning hole passes through its cutting surface and is at a certain distance from the air path channel of the first steering valve. There is a preset angle between the angle positioning hole and the air path positioning hole.

3. The gas sampling rotary valve according to claim 1, characterized in that: A positioning hole is provided at one end of the second steering valve extending into the main frame. The second detection mechanism emits light under the control of an external electronic control device, and identifies the rotation state of the second steering valve based on the state of the light penetrating the positioning hole. The positioning hole of the second steering valve and the through hole of the second steering valve are perpendicular to each other in space.

4. The gas sampling rotary valve according to claim 1, characterized in that: A slot hole is arranged on one side of the valve body connected to the motor, and a rotating shaft is embedded therein. The outer diameter of the rotating shaft matches the inner diameter of the slot hole of the valve body, and the rotating shaft is connected to the motor.

5. The gas sampling rotary valve according to claim 4, characterized in that: The rotating shaft and the valve body are made of the same or different materials, and the valve body and the main frame are made of the same or different materials. When they are the same, they are both made of rigid materials; when they are different, the valve body is made of flexible materials, and the rotating shaft and the main frame are made of rigid materials.

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