Method and system for measuring pressure of microwave digestion tank

Abstract

The invention discloses a pressure measuring method and system for a microwave digestion tank. The method comprises the following steps: a data acquisition stage: acquiring an initial coordinate position of the top of a floating plug; introducing gas with a known pressure value into the digestion cavity; recording the coordinate position of the top of the floating plug after the gas is introduced; the pressure of the gas introduced into the digestion cavity is changed, the coordinate position of the top of the corresponding floating plug is recorded, and a plurality of pairs of gas pressure and the position of the top of the floating plug are obtained and stored after the gas with different pressure is introduced for multiple times; and a pressure measuring stage: carrying out digestion reaction in the digestion cavity, reading the coordinate position of the top of the floating plug, and obtaining a corresponding pressure value as the internal pressure of the current digestion cavity according to the relationship between the stored gas pressure and the position of the top of the floating plug. Therefore, the pressure change in the digestion cavity is converted into the movement condition of the floating plug for visualization, so that in the actual reaction and pressure measurement process, the pressure does not need to be tested independently, and an accurate pressure result can be obtained only through an optical instrument.

Description

Technical Field

[0001] This invention relates to the field of microwave digestion instrument technology, and in particular to a microwave digestion vessel pressure measurement method and system. Background Technology

[0002] Microwave digestion technology achieves rapid sample decomposition through microwave heating within a sealed container, and its pressure parameters directly determine experimental safety and digestion efficiency. With the increasing demands for trace analysis in environmental, food, and other fields, pressure measurements must simultaneously meet stringent conditions such as high temperature and pressure, strong acid corrosion, and microwave field interference.

[0003] However, with the development of technology, digestion vessels often need to rotate inside a microwave cavity. However, traditional contact pressure sensors cannot rotate synchronously with the vessel, and wiring and signal transmission are prone to interruption and line breakage, making it impossible to monitor the pressure of each vessel. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a microwave digestion vessel pressure measurement method and system.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] In a first aspect, this application discloses a method for measuring pressure in a microwave digestion vessel. The digestion vessel includes a vessel body defining a digestion chamber and a float plug with its lower end disposed inside the digestion chamber and its upper end exposed outside the digestion chamber. The method includes: a data acquisition stage: acquiring the initial coordinate position of the top of the float plug; introducing gas with a known pressure value into the digestion chamber; recording the coordinate position of the top of the float plug after the gas is introduced; changing the gas pressure introduced into the digestion chamber and recording the corresponding coordinate position of the top of the float plug; after introducing gas with different pressures multiple times, obtaining several pairs of gas pressure and float plug top positions, and storing them; a pressure measurement stage: performing a digestion reaction in the digestion chamber, reading the coordinate position of the top of the float plug, and obtaining the corresponding pressure value as the internal pressure of the current digestion chamber based on the relationship between the stored gas pressure and the float plug top position.

[0007] The beneficial effects of this invention are as follows: By setting a float that can move up and down with changes in pressure within the digestion chamber, the pressure changes within the digestion chamber can be visualized as the movement of the float. This allows for the acquisition of the float's displacement coordinates using optical equipment, thus obtaining a definite relationship between pressure and displacement. Consequently, in subsequent actual reaction and pressure measurement processes, there is no need for separate pressure testing; accurate pressure results can be obtained solely through optical instruments.

[0008] Furthermore, by emitting a laser to the top of the float, a CCD camera acquires an image of the laser spot on the top of the float to calculate the current coordinate position of the top of the float.

[0009] Furthermore, the laser emitter continuously emits laser light, and the CCD image sensor acquires real-time images of the light spot reflected from the top of the tank. The signal processing module then extracts the center coordinates (x, y) of the light spot. n ,y n Given the current position coordinates, calculate the displacement between these coordinates and the reference position coordinates. , where (x0, y0) are the initial position coordinates.

[0010] Furthermore, the displacement ΔS is substituted into the preset linear calibration model, and the noise interference caused by the microwave field and rotational vibration is filtered out by the filtering algorithm to obtain the real-time pressure value in the elimination cavity.

[0011] Furthermore, the linear calibration model is: P = k × ΔS + b; where P is the pressure value, k is the calibration coefficient, ΔS is the spot displacement, and b is the correction constant.

[0012] Furthermore, the upper half of the float plug passes through the can lid, and the upper end of the float plug is located outside the digestion chamber and connected to the pressure port. At least part of the upper half of the float plug is exposed outside the can lid, and the exposed part of the float plug moves up and down with the pressure change in the digestion chamber.

[0013] Furthermore, the float plug has an internal air intake channel that connects to the digestion chamber and the pressure port to allow air to be supplied to the digestion chamber through the pressure port; the float plug has a flange on its periphery, and an elastic element is provided between the upper surface of the flange and the lower surface of the top of the can lid, the elastic element extending and retracting along the movement direction of the float plug.

[0014] Secondly, this application discloses a microwave digestion vessel pressure measurement system, including a processor and a storage device, wherein the storage device stores the microwave digestion vessel pressure measurement method, and the processor performs read and write operations on the storage device. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a microwave digestion vessel according to some embodiments of this application;

[0016] Figure 2 This is a cross-sectional structural schematic diagram of a microwave digestion vessel according to some embodiments of this application;

[0017] Figure 3 This is a schematic diagram of the structure of the float, elastic element, and plug according to some embodiments of this application;

[0018] Figure 4 This is an isometric view of a microwave digestion vessel according to some embodiments of this application.

[0019] In the picture:

[0020] 100-Microwave Digestion Vessel;

[0021] 110 - Tank body;

[0022] 120 - Can lid;

[0023] 130 - Float plug;

[0024] 131-Pressure port, 132-Intake passage, 133-Flange, 134-Elastic plug, 135-Inner plug, 1351-Vent hole;

[0025] 140 - Elastic element;

[0026] 150-Connecting sleeve. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] A microwave digestion vessel pressure measurement method according to an embodiment of this application is implemented based on a microwave digestion vessel.

[0029] First refer to Figure 1-4 The microwave digestion vessel includes a vessel body 110, a lid 120 disposed on the vessel body 110, and a float 130.

[0030] The container 110 is cylindrical in shape and made of high-temperature and corrosion-resistant materials such as polytetrafluoroethylene (PTFE) or modified polyetheretherketone (PEEK). It contains the sample and digestion solution. The container lid 120 is fixed to the upper end of the container 110 by threads or snap fasteners to ensure overall sealing.

[0031] The lower half of the float plug 130 is disposed inside the container body 110. The outer periphery of the lower end of the float plug 130 is fitted against the inner wall of the container body 110 to form a seal, thereby defining a sealed digestion chamber between the lower end of the float plug 130 and the container body 110 for sample digestion reactions under microwave heating. Thus, when the pressure inside the digestion chamber changes, because the pressure above the float plug 130 is atmospheric pressure, and the internal pressure is greater than atmospheric pressure, it will move upwards under the influence of the pressure difference. (Reference) Figure 2The upper half of the float plug 130 passes through the can lid 120, and the upper end of the float plug 130 is located outside the digestion chamber and connected to the pressure port 131 to pressurize the digestion chamber by introducing air through the pressure port 131. At least part of the upper half of the float plug 130 is exposed outside the can lid 120, and the exposed part of the float plug 130 moves up and down with changes in pressure within the digestion chamber. The float plug 130 has an internal air inlet channel 132, which connects to both the digestion chamber and the pressure port 131, allowing air to be introduced into the digestion chamber through the pressure port 131.

[0032] In other words, the height of the exposed upper portion of the float 130 moves up and down with changes in pressure within the digestion chamber. When the microwave digestion process begins, the sample inside the container is heated, generating gas or vapor, which causes the pressure in the digestion chamber to increase. Due to the seal between the lower end of the float 130 and the inner wall of the container 110, the pressure increase directly acts on the lower end face of the float 130, pushing it upwards; there is a fixed relationship between this upward displacement and the pressure change. Therefore, users can obtain the displacement of the exposed portion of the float 130 using optical equipment or scales, thereby estimating the internal pressure state.

[0033] The float plug 130 has a flange 133 on its periphery. An elastic element 140 is provided between the upper surface of the flange 133 and the lower surface of the top of the can lid 120. The elastic element 140 extends and retracts along the direction of movement of the float plug 130. (Reference) Figure 2 The elastic element 140 is cylindrical in shape and can be made of rubber or other corrosion-resistant elastic materials. By setting this elastic element 140, a reaction force can be generated to resist the upward movement of the float 130 when the internal pressure of the digestion chamber changes, so that it maintains a slow upward process and does not move violently upward after the internal pressure changes.

[0034] An elastic plug 134 is provided on the circumference of the lower end of the float plug 130. The inner circumferential wall of the elastic plug 134 is tightly disposed with the inner sidewall of the float plug 130. It can be directly integrally disposed with the lower end of the float plug 130, or it can be bonded to the lower end of the float plug 130. When the float plug 130 moves upward, it will generate a radial compression process, which will increase the diameter of the elastic plug 134 to maintain the sealing of the digestion chamber. Specifically, the tank body 110 and the tank cover 120 are connected by a connecting sleeve 150. An inner sleeve extends from the inner circumference of the connecting sleeve 150. The inner sleeve fits against the inner circumferential wall of the tank body 110, and the lower end of the inner sleeve fits against the upper end face of the plug. After the float plug 130 moves upward, the float plug 130 is compressed and undergoes radial deformation.

[0035] In detail, the lower end of the float plug 130 is provided with an inner plug 135, and the center of the inner plug 135 has a vent hole 1351. The vent hole 1351 is connected to the air inlet channel 132 inside the float plug 130, so that external gas enters the digestion chamber through the vent hole 1351. Then the inner plug 135 and the outer plug seal it to the can lid 120 and the outside, thereby causing the float plug 130 to move upward based on the pressure difference between the inside and outside of the digestion chamber.

[0036] Based on this, the microwave digestion vessel pressure measurement method of this application includes a data acquisition stage and a pressure measurement stage.

[0037] In detail, in the embodiments of this application, the microwave digestion vessel 100 of the aforementioned embodiment, as well as a laser emitter (not shown in the figure) and a CCD camera (not shown in the figure) are provided in the microwave cavity defined within the microwave unit of the microwave digestion instrument.

[0038] During the data acquisition phase, a laser is emitted to the top of the float, and a CCD camera captures the laser spot image on the top of the float, thereby calculating the initial coordinate position of the float's top. Then, gas at a known pressure is introduced into the digestion chamber, and the coordinate position of the float's top after gas introduction is recorded. The gas pressure introduced into the digestion chamber is then changed, and the corresponding coordinate position of the float's top is recorded. After introducing gas at different pressures multiple times, several pairs of gas pressure and float top position are obtained and stored.

[0039] For example, an inert gas (which does not react with strong acid) with a known pressure value (such as 0.1 MPa, 0.2 MPa, 0.3 MPa) is introduced into the tank, and the displacement coordinates (x1, y1), (x2, y2), and (x3, y3) of the light spot are recorded at different pressures to establish a linear calibration model of "pressure value - light spot displacement":

[0040] P = k × ΔS + b, where P is the pressure value, k is the calibration coefficient, ΔS is the spot displacement, and b is the correction constant.

[0041] In this way, in the subsequent actual reaction and pressure measurement process, there is no need to test the pressure separately, and accurate pressure results can be obtained solely through optical instruments.

[0042] Therefore, during the pressure measurement stage: microwave heating and the digestion reaction in the digestion chamber generate pressure. The coordinate position of the top of the float is read, and the corresponding pressure value is obtained based on the relationship between the stored gas pressure and the position of the top of the float to obtain the current internal pressure of the digestion chamber.

[0043] Specifically, a microwave field and a tank rotation system can be activated to assist the photoelectric sensor in identifying the tank number currently passing through the optical window, and simultaneously trigger the optical sensing component to operate; the laser emitter continuously emits laser light, and the CCD image sensor acquires images of the light spot reflected from the elastically deformed protrusion on the tank top in real time, and the signal processing module extracts the center coordinates (x, y) of the light spot. n ,y n ), calculate its displacement relative to the reference position coordinates. ; where (x0, y0) are the initial position coordinates.

[0044] Substituting the displacement ΔS into the preset linear calibration model, and combining the filtering algorithm to filter out noise interference caused by microwave field and rotational vibration, the real-time pressure value inside the tank is obtained.

[0045] In some embodiments, the "tank number - real-time pressure value" can be stored through an external signal processing module and uploaded to the terminal system through a communication interface to achieve data visualization and over-limit alarm.

[0046] The microwave digestion vessel pressure measurement system according to the embodiments of this application includes a processor and a storage device. The storage device stores the microwave digestion vessel pressure measurement method, and the processor performs read and write operations on the storage device.

[0047] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for measuring pressure in a microwave digestion vessel, characterized in that, The digestion vessel includes a vessel body defining a digestion chamber and a float plug with its lower end disposed within the digestion chamber and its upper end exposed outside the digestion chamber. The method includes: Data acquisition phase: Obtain the initial coordinate position of the top of the float plug; introduce gas with a known pressure value into the digestion chamber; record the coordinate position of the top of the float plug after the gas is introduced; The gas pressure introduced into the digestion chamber was changed, and the corresponding coordinate position of the top of the float was recorded. After introducing gas at different pressures multiple times, several pairs of gas pressure and float top position were obtained and stored. Pressure testing phase: The digestion reaction takes place inside the digestion chamber. The coordinate position of the top of the float is read, and the corresponding pressure value is obtained based on the relationship between the stored gas pressure and the position of the top of the float. This value represents the internal pressure of the current digestion chamber.

2. The microwave digestion vessel pressure measurement method according to claim 1, characterized in that, A laser is emitted to the top of the float, and a CCD camera captures an image of the laser spot on the top of the float to calculate the current coordinate position of the top of the float.

3. The microwave digestion vessel pressure measurement method according to claim 2, characterized in that, The laser emitter continuously emits laser light, and the CCD image sensor acquires images of the reflected light spot from the top of the tank in real time. The signal processing module then extracts the center coordinates (x, y) of the light spot. n ,y n Given the current position coordinates, calculate the displacement between these coordinates and the reference position coordinates. , where (x0, y0) are the initial position coordinates.

4. The microwave digestion vessel pressure measurement method according to claim 3, characterized in that, Substituting the displacement ΔS into the preset linear calibration model, the real-time pressure value inside the digestion chamber is obtained.

5. The microwave digestion vessel pressure measurement method according to claim 4, characterized in that, The linear calibration model is as follows: P = k × ΔS + b; Where P is the pressure value, k is the calibration coefficient, ΔS is the spot displacement, and b is the correction constant.

6. The microwave digestion vessel pressure measurement method according to claim 1, characterized in that, The upper end of the float plug is located outside the digestion chamber and connected to the pressure port. At least part of the upper half of the float plug is exposed outside the can lid. The exposed part of the float plug moves up and down with the pressure change inside the digestion chamber.

7. The microwave digestion vessel pressure measurement method according to claim 6, characterized in that: The float plug has an internal air intake channel that connects to the digestion chamber and the pressure port, so as to allow air to be supplied to the digestion chamber through the pressure port. The float is provided with a flange on its periphery, and an elastic element is provided between the upper plane of the flange and the lower plate of the top of the can lid. The elastic element extends and retracts along the direction of movement of the float.

8. A microwave digestion vessel pressure measurement system, characterized in that, It includes a processor and a storage device, wherein the storage device stores the microwave digestion vessel pressure measurement method according to any one of claims 1-7, and the processor performs read and write operations on the storage device.

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