CN112525411B - Device and method for testing pressure in glass beads based on differential pressure method - Google Patents
Device and method for testing pressure in glass beads based on differential pressure method Download PDFInfo
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- CN112525411B CN112525411B CN202011216727.5A CN202011216727A CN112525411B CN 112525411 B CN112525411 B CN 112525411B CN 202011216727 A CN202011216727 A CN 202011216727A CN 112525411 B CN112525411 B CN 112525411B
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- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
Abstract
The invention relates to a device and a method for testing the internal pressure of glass microspheres based on a differential pressure method, which belong to the technical field of hollow glass microsphere testing, wherein the device for testing the internal pressure of the glass microspheres based on the differential pressure method comprises a measuring cavity, a comparison cavity, a hydraulic device, a differential pressure gauge, an absolute pressure gauge, thermocouples and a high-pressure gas cylinder, wherein pistons are arranged in the measuring cavity and the comparison cavity, the driving ends of the hydraulic device are respectively connected with the upper ends of two groups of pistons, the measuring ends of the two groups of thermocouples are respectively positioned in the measuring cavity and the comparison cavity, the bottom ends of the measuring cavity and the comparison cavity are respectively connected with the absolute pressure gauge through a pipeline, the differential pressure gauge is positioned on a pipeline between the bottom ends of the measuring cavity and the comparison cavity, and the gas inlet end of the high-pressure gas cylinder is respectively connected with the measuring cavity and the comparison cavity; the pressure of the inner bottom of the measuring cavity is increased to the MPa magnitude, and the pressure value of the inner hollow glass bead can be accurately measured by matching the hollow glass bead and the hollow glass bead within 5 atmospheric pressures by matching the comparison cavity and the differential pressure gauge.
Description
Technical Field
The invention belongs to the technical field of hollow glass bead testing, and particularly relates to a device and a method for testing pressure in glass beads based on a differential pressure method.
Background
The hollow glass bead is a hollow glass sphere with tiny size, has the advantages of light weight, low heat conduction, sound insulation, high dispersion, good electrical insulation property, good thermal stability and the like, can realize vacuum distribution in the glass bead by a vacuum technical means, reduces the vacuum degree in the vacuum glass bead and the heat conductivity coefficient compared with the traditional glass bead, has good heat insulation performance, and is more suitable for being used as a heat insulation material or a material filler. Therefore, how to test the gas pressure in the hollow glass microsphere is very important. The gas pressure in the hollow glass beads is an important characterization index of the hollow glass beads, the gas pressure in the hollow glass beads cannot be restricted during testing, and the existing pressure testing device and the existing pressure testing method are not complete in testing the materials of the type. Therefore, a device and a method for testing the pressure in the glass beads based on a differential pressure method are provided.
Disclosure of Invention
The invention aims to solve the problems and provide a device and a method for testing the pressure in glass beads based on a differential pressure method, which have simple structure and reasonable design.
The invention realizes the purpose through the following technical scheme:
the utility model provides a glass bead internal pressure testing arrangement based on differential pressure method, is including measuring chamber, contrast chamber, hydraulic means, differential pressure gauge, absolute pressure gauge, thermocouple, gas cylinder, measure chamber, contrast intracavity and all be equipped with the piston, just the upper end of two sets of pistons is connected respectively to hydraulic means's drive end, and the measuring end of two sets of thermocouples is located respectively and measures chamber, contrast intracavity, the bottom of measuring chamber, contrast chamber all is through the pipe connection absolute pressure gauge, just the differential pressure gauge is located the pipeline between measuring chamber, the contrast chamber bottom, measurement chamber, contrast chamber are connected respectively to the inlet end of gas cylinder.
As a further optimization scheme of the invention, a balance valve is further arranged on a pipeline between the bottom ends of the measurement cavity and the comparison cavity, and the balance valve and the differential pressure gauge are positioned on two groups of parallel pipelines.
As a further optimization scheme of the invention, a stop valve is arranged at the air inlet end of the high-pressure air bottle.
A method for testing the pressure in glass beads based on a differential pressure method comprises the following steps:
step 1: weighing hollow glass beads with the mass of m, filling the hollow glass beads into a measurement cavity, filling solid glass beads with the same volume into a comparison cavity, and pressing two pistons to the inlet positions of a cavity of the measurement cavity and the cavity of the comparison cavity respectively;
step 2: opening a stop valve at the gas inlet end of a high-pressure gas bottle, closing the stop valve after high-pressure gas fills a measurement cavity and a comparison cavity, opening a balance valve between the measurement cavity and the comparison cavity until the pressures in the two cavities are balanced, closing the balance valve, and collecting the front temperature T of compressed gas in the measurement cavity and the gas pressure P in the measurement cavity at the moment;
and step 3: starting a hydraulic device to drive a piston to compress high-pressure gas in a measuring cavity and a comparison cavity, moving the piston downwards until the hollow glass beads are completely crushed, closing the hydraulic device, and recording the change value of the absolute pressure of the measuring cavity and the comparison cavity, the differential pressure value delta P of the pressure before and after the hollow glass beads in the measuring cavity (1) are crushed and the temperature T of the measuring cavity at the lowest value of the pressure of the measuring cavity in the moving process of the piston;
and 4, step 4: obtaining the internal pressure value P of the hollow glass microsphere according to an ideal gas equationXAnd the gas pressure P of the measuring cavity before the micro-beads are broken2And temperature T0And the gas pressure P of the measuring cavity after the micro-beads are broken1And T2And measuring the relation of the differential pressure value delta P of the pressure before and after the hollow glass microsphere in the cavity (1) is broken, thereby obtaining the internal pressure value P of the hollow glass microsphereXA value of (d);
as a further optimization scheme of the invention, the internal pressure value P of the hollow glass beadXAnd the gas pressure P of the measuring cavity before the micro-beads are broken2And temperature T0And the gas pressure P of the measuring cavity after the micro-beads are broken1And T2And the relation of the differential pressure value delta P of the pressure intensity before and after the hollow glass beads in the measuring cavity (1) are as follows:
PXVball+P2(V1-Vball)＝P1V1 (1)
P2＝P1+ΔP (3)
combining the formulas (1), (2) and (3) to obtain the internal pressure value P of the hollow glass microsphereX：
In the formula:
V0for measuring the total volume of the cavity, in mm3；
V1For measuring the volume of the cavity after compression, in mm3；
VballIs the volume occupied by the hollow glass micro-beads and the unit is mm3。
As a further optimization scheme of the present invention, in the formula (4):
substitution of formula (5) into formula (4) gives:
n is the number of hollow glass microspheres;
Dballthe average particle size of the hollow glass microspheres is in mm.
As a further optimization scheme of the present invention, in the formula (5):
substituting (7) into (6) yields:
and m is the mass of the hollow glass bead, and the unit is kg.
ρballThe sphere density of the hollow glass microspheres is kg/m3。
The invention has simple structure and reasonable design, and has the following beneficial effects:
1. the device adopts the differential pressure gauge to match with the comparison chamber to measure the pressure change of the chamber before and after the hollow glass beads are crushed, the measuring method is reliable, and the measuring result is more accurate;
2. the device can crush the hollow glass beads by compressing high-pressure gas, and compared with a mechanical crushing device, the device can crush the hollow glass beads more uniformly and has higher crushing efficiency;
3. by improving the background pressure in the measuring chamber to the MPa magnitude and matching with a comparison chamber and a differential pressure gauge, the internal pressure value of the hollow glass beads can be accurately measured for the hollow glass beads with negative pressure inside and the positive pressure hollow glass beads with the pressure within 5 atmospheric pressures;
4. the piston is driven by a hydraulic device to compress gas in the closed space, so that tens of thousands of hollow glass microspheres are crushed, the number of the hollow glass microspheres can be calculated by weighing through a precision balance, the pressure change in the chamber can be measured by a differential pressure gauge, and the difficulties of high measurement difficulty and low measurement precision of single micro-nano glass microsphere are avoided.
Drawings
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is a graph illustrating the variation of gas pressure in the measurement chamber;
FIG. 3 is a graph comparing changes in gas pressure in chambers.
In the figure: 1. a measurement cavity; 2. a contrast chamber; 3. a hydraulic device; 4. a differential pressure gauge; 5. an absolute pressure meter; 6. a thermocouple; 7. a high pressure gas cylinder; 8. a piston; 9. a balancing valve; 10. and a stop valve.
Detailed Description
The present application will now be described in further detail with reference to the drawings, it should be noted that the following detailed description is given for illustrative purposes only and is not to be construed as limiting the scope of the present application, as those skilled in the art will be able to make numerous insubstantial modifications and adaptations to the present application based on the above disclosure.
As shown in fig. 1, the pressure testing device in glass beads based on differential pressure method in this embodiment includes a measuring chamber 1, a comparison chamber 2, a hydraulic device 3, a differential pressure gauge 4, an absolute pressure gauge 5, a thermocouple 6, and a high pressure gas cylinder 7, wherein pistons 8 are respectively disposed in the measuring chamber 1 and the comparison chamber 2, the driving end of the hydraulic device 3 is respectively connected to the upper ends of the two sets of pistons 8, the measuring ends of the two sets of thermocouples 6 are respectively located in the measuring chamber 1 and the comparison chamber 2, the bottom ends of the measuring chamber 1 and the comparison chamber 2 are respectively connected to the absolute pressure gauge 5 through a pipeline, the differential pressure gauge 4 is located on the pipeline between the bottom ends of the measuring chamber 1 and the comparison chamber 2, a balance valve 9 is further disposed on the pipeline between the bottom ends of the measuring chamber 1 and the comparison chamber 2, the balance valve 9 and the differential pressure gauge 4 are located on the two sets of parallel pipelines, the gas inlet end of the high pressure gas cylinder 7 is respectively connected to the measuring chamber 1 and the comparison chamber 2, and the gas inlet end of the high pressure gas cylinder 7 is provided with a stop valve 10, the gas is nitrogen gas in the high-pressure gas cylinder 7, high-pressure nitrogen gas gets into through the valve and measures chamber 1 and contrast chamber 2, hydraulic means 3 is through the drive piston downstream, compress two intracavity nitrogen gas, pressure risees to measure the hollow glass microballon in the chamber 1 and takes place the breakage, adopt 5 record compression process background pressure changes of absolute pressure meter, differential pressure meter 4 record measures the pressure differential change between chamber 1 and the contrast chamber 2, through measuring the pressure change before and after the hollow glass microballon is broken, solve and calculate single hollow glass microballon internal pressure value.
The measuring cavity 1 and the comparison cavity 2 adopt cylinders with the diameter of 20mm, the wall thickness of 5mm and the length of 500mm, and the inflation pressure of a high-pressure nitrogen cylinder is 0.6 MPa.
The method for testing the pressure in the glass beads based on the differential pressure method by adopting the device comprises the following steps:
step 1: weighing 0.2g of hollow glass microspheres by using a precision balance, filling the hollow glass microspheres into a measurement cavity 1, filling solid glass microspheres with the same volume into a comparison cavity 2, and pressing two pistons 8 to the inlet positions of cavities of the measurement cavity 1 and the comparison cavity 2 respectively;
step 2: opening 7 inlet end stop valves 10 of high-pressure gas cylinder, closing stop valves 10 after high-pressure gas is filled in measuring chamber 1 and contrast chamber 2, opening balance valve 9 between measuring chamber 1 and contrast chamber 2 to close balance valve 9 after pressure balance in two chambers, collecting temperature T before measuring chamber 1 compressed gas at the moment0And measuring the gas pressure P in the chamber 10；
And step 3: starting upThe hydraulic device 3 drives the piston 8 to compress high-pressure gas in the measurement cavity 1 and the comparison cavity 2, the piston 8 moves downwards to 450mm and then closes the hydraulic device 3, and the change value and the differential pressure value delta P of the absolute pressure of the measurement cavity 1 and the comparison cavity 2 and the temperature T of the measurement cavity 1, which is the lowest value of the pressure of the measurement cavity 1, in the moving process of the piston 8 are recorded2；
The change values of the absolute pressures of the measurement cavity 1 and the comparison cavity 2 in the moving process of the piston 8 are shown in fig. 2 and fig. 3, at the initial stage of the downward movement process of the piston 8, the pressures in the two cavities are lower than the crushing pressure of the hollow glass beads and are about 4MPa, the pressures in the two cavities are basically equal at the moment, the reading of a differential pressure gauge 4 is 0, the pressure in the measurement cavity is continuously increased until 6MPa along with the gradual increase of the piston stroke until 450mm, the breakage of the hollow glass beads is finished, and the pressure in the measurement cavity is rapidly reduced to P because the pressure in the hollow glass beads is far lower than the background pressure of the cavities1Accurately measuring the differential pressure value delta P of the two chambers through a differential pressure gauge;
and 4, step 4: obtaining the internal pressure value P of the hollow glass microsphere according to an ideal gas equationXThe gas pressure P of the measuring cavity 1 before the micro-beads are broken2And temperature T0The gas pressure P of the measuring cavity 1 after the micro-beads are broken1And T2And the relation of the differential pressure value Δ P:
PXVball+P2(V1-Vball)＝P1V1 (1)
P2＝P1+ΔP (3)
in the formula:
combining the formulas (1), (2) and (3) to obtain the internal pressure value P of the hollow glass microsphereX：
In the formula (4):
substituting the formula (5) into the formula (4) to obtain the internal pressure value P of the hollow glass microsphereXThe value of (c):
PXthe pressure value is the internal pressure value of the hollow glass microsphere, and the unit is Pa;
P0measuring the gas pressure in the cavity in Pa;
Δ P is the differential pressure value in Pa;
T0the temperature of the gas before compression in the cavity is measured, and the unit is K;
T2measuring the temperature of the compressed gas in the cavity after compression, wherein the unit is K;
V0for measuring the total volume of the chamber 1, in mm3；
V1For measuring the volume of the chamber 1 after compression, in mm3；
VballIs the volume occupied by the hollow glass micro-beads and the unit is mm3；
n is the number of hollow glass microspheres;
Dballthe average grain diameter of the hollow glass microspheres is in mm;
sphere density ρ of hollow glass microspheres is knownballAverage particle diameter DballThe number of the hollow glass beads can be obtained by a weighing method, and the number of the hollow glass beads contained in 0.2g is calculated to be about 76 thousands.
The calculation formula is as follows:
substituting (7) into (6) yields:
and m is the mass of the hollow glass bead, and the unit is kg.
ρballThe sphere density of the hollow glass microspheres is kg/m3；
Through preliminary calculation, when the background pressure in the measuring cavity 1 reaches the crushing pressure of the hollow glass beads to be 4MPa, the pressure in the cavity can be changed by 0.09Pa due to the crushing of a single hollow bead, the pressure change generated by crushing of 0.2g of the hollow glass beads can reach 65KPa, and the internal pressure value of the hollow glass beads can be accurately obtained through the measuring device and the measuring method.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.
Claims (7)
1. A glass bead internal pressure testing device based on a differential pressure method is characterized by comprising a measuring cavity (1), a comparison cavity (2), a hydraulic device (3), a differential pressure gauge (4), an absolute pressure gauge (5), a thermocouple (6) and a high-pressure gas cylinder (7), the measuring cavity (1) and the comparison cavity (2) are both internally provided with pistons (8), the driving end of the hydraulic device (3) is respectively connected with the upper ends of two groups of pistons (8), the measuring ends of two groups of thermocouples (6) are respectively positioned in the measuring cavity (1) and the comparison cavity (2), the bottom ends of the measuring cavity (1) and the comparison cavity (2) are connected with an absolute pressure meter (5) through pipelines, and the differential pressure gauge (4) is positioned on the pipeline between the bottom ends of the measuring cavity (1) and the contrast cavity (2), and the air inlet end of the high-pressure air bottle (7) is respectively connected with the measuring cavity (1) and the comparison cavity (2).
2. The apparatus for testing the pressure inside a glass microbead based on the differential pressure method as claimed in claim 1, wherein: the pipeline between the bottom ends of the measurement cavity (1) and the comparison cavity (2) is also provided with a balance valve (9), and the balance valve (9) and the differential pressure gauge (4) are positioned on two groups of parallel pipelines.
3. The apparatus for testing the pressure inside a glass microbead based on the differential pressure method as claimed in claim 2, wherein: and a stop valve (10) is arranged at the air inlet end of the high-pressure air bottle (7).
4. A method for testing the pressure in glass microspheres based on a differential pressure method, which adopts the device for testing the pressure in glass microspheres based on the differential pressure method as claimed in claim 3, and is characterized by comprising the following steps:
step 1: weighing hollow glass beads with the mass of m, filling the hollow glass beads into a measurement cavity (1), filling solid glass beads with the same volume into a comparison cavity (2), and pressing two pistons (8) to the inlet positions of cavities of the measurement cavity (1) and the comparison cavity (2) respectively;
step 2: opening high-pressure gas bottle (7) inlet end stop valve (10), closing stop valve (10) after high-pressure gas is full of measurement chamber (1) and contrast chamber (2), opening balance valve (9) between measurement chamber (1) and contrast chamber (2) and closing balance valve (9) after pressure balance in two chambers, collecting temperature T before measuring chamber (1) compressed gas this moment0And measuring the gas pressure P in the chamber (1)0；
And step 3: high-pressure gas in the measurement cavity (1) and the comparison cavity (2) is compressed by a driving piston (8) of a hydraulic device (3), the piston (8) moves downwards to close the hydraulic device (3) after the hollow glass beads are completely crushed, the change values of the absolute pressure of the measurement cavity (1) and the comparison cavity (2) in the moving process of the piston (8), the differential pressure value delta P of the pressure intensity before and after the hollow glass beads are crushed in the measurement cavity (1) and the temperature T of the measurement cavity (1) of the lowest pressure value in the measurement cavity (1) are recorded2；
And 4, step 4: obtaining the internal pressure value P of the hollow glass microsphere according to an ideal gas equationXThe gas pressure P of the measuring cavity (1) before the micro-beads are broken2And temperature T0The gas pressure P of the measuring cavity (1) after the micro-beads are broken1And temperature T2And measuring the relation of the differential pressure value delta P of the pressure before and after the hollow glass microsphere in the cavity (1) is broken, thereby obtaining the internal pressure value P of the hollow glass microsphereXThe value of (c).
5. The method for testing the pressure in glass microspheres according to claim 4, wherein the method comprises the following steps: the internal pressure value P of the hollow glass beadXThe gas pressure P of the measuring cavity (1) before the micro-beads are broken2And temperature T0The gas pressure P of the measuring cavity (1) after the micro-beads are broken1And temperature T2And the relation of the differential pressure value delta P of the pressure intensity before and after the hollow glass beads in the measuring cavity (1) are as follows:
PXVball+P2(V1-Vball)＝P1V1 (1)
P2＝P1+ΔP (3)
combining the formulas (1), (2) and (3) to obtain the internal pressure value P of the hollow glass microsphereX：
In the formula:
V0for measuring the total volume of the cavity (1), in mm3；
V1For measuring the volume of the cavity (1) after compression, the unit is mm3；
VballIs the volume occupied by the hollow glass micro-beads and the unit is mm3。
6. The method for testing the pressure in glass microspheres according to claim 5, wherein the method comprises the following steps: in the formula (4):
substitution of formula (5) into formula (4) gives:
n is the number of hollow glass microspheres;
Dballthe average particle size of the hollow glass microspheres is in mm.
7. The method for testing the pressure in glass microspheres according to claim 6, wherein the method comprises the following steps: in the formula (5):
substituting (7) into (6) yields:
m is the mass of the hollow glass bead, and the unit is kg;
ρballthe sphere density of the hollow glass microspheres is kg/m3。
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| US4303732A (en) * | 1979-07-20 | 1981-12-01 | Torobin Leonard B | Hollow microspheres |
| US20130291645A1 (en) * | 2012-05-01 | 2013-11-07 | James H. Gammon | Differential pressure gauge |
| CN205920017U (en) * | 2015-12-30 | 2017-02-01 | 中国建材国际工程集团有限公司 | Survey device of hollow glass microballon water -resistant isostatic pressing intensity |
| US20170146415A1 (en) * | 2015-11-24 | 2017-05-25 | Toyota Jidosha Kabushiki Kaisha | Cylinder Internal Pressure Sensor |
| CN110736584A (en) * | 2019-10-29 | 2020-01-31 | 合肥工业大学 | device and method for measuring vacuum degree in hollow glass beads |
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- 2020-11-04 CN CN202011216727.5A patent/CN112525411B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4303732A (en) * | 1979-07-20 | 1981-12-01 | Torobin Leonard B | Hollow microspheres |
| US20130291645A1 (en) * | 2012-05-01 | 2013-11-07 | James H. Gammon | Differential pressure gauge |
| US20170146415A1 (en) * | 2015-11-24 | 2017-05-25 | Toyota Jidosha Kabushiki Kaisha | Cylinder Internal Pressure Sensor |
| CN205920017U (en) * | 2015-12-30 | 2017-02-01 | 中国建材国际工程集团有限公司 | Survey device of hollow glass microballon water -resistant isostatic pressing intensity |
| CN110736584A (en) * | 2019-10-29 | 2020-01-31 | 合肥工业大学 | device and method for measuring vacuum degree in hollow glass beads |
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| 空心玻璃微珠抗压强度检测方法及原理;彭小波等;《2013全国玻璃科学技术年会论文集》;20130518;第194-198页 * |
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