阅读说明：本技术 适于高压环境下粉体的气体穿透性及应力测量装置及方法 (Gas penetrability and stress measuring device and method suitable for powder under high-pressure environment ) 是由 梁财 骆兵 王欣 陈晓平 刘道银 马吉亮 于 2021-07-02 设计创作，主要内容包括：本发明涉及一种适于高压环境下粉体的气体穿透性及应力测量装置和实验方法,装置包括料仓筒,设置在料仓筒上端的上封头和设置在料仓筒下端的下封头；上封头上设有进料口、压力表、安全阀和上通气孔；下封头上设有下通气孔和出料口；料仓筒及下封头壁面自上而下设有传感器。本装置中传感器可同时获得高压环境下不同位置的气体压力及粉体应力,根据气体压力和粉体应力可获得气体穿透特性、粉体的压缩及固结机制；通过剪切实验获得充压后粉体的基础力学参数,可揭示粉体充压过程中粉体流动特性变化规律及成拱机制。根据气体的穿透特性、不同升压速率下的粉体压缩及固结机制,可优化充压料仓几何结构及充压操作参数,确保高压环境下粉体流动的稳定性。(The invention relates to a device and an experimental method for measuring gas penetrability and stress of powder in a high-pressure environment, wherein the device comprises a bin cylinder, an upper end socket arranged at the upper end of the bin cylinder and a lower end socket arranged at the lower end of the bin cylinder; the upper end enclosure is provided with a feed inlet, a pressure gauge, a safety valve and an upper vent hole; the lower end enclosure is provided with a lower vent hole and a discharge hole; sensors are arranged on the wall surfaces of the material bin barrel and the lower end enclosure from top to bottom. The sensor in the device can simultaneously obtain gas pressure and powder stress at different positions in a high-pressure environment, and can obtain gas penetration characteristics and a powder compression and consolidation mechanism according to the gas pressure and the powder stress; basic mechanical parameters of the powder after being pressurized are obtained through a shearing experiment, and the change rule of the flow characteristic of the powder and the arching mechanism in the powder pressurizing process can be revealed. According to the penetration characteristic of gas and the powder compression and consolidation mechanisms under different pressure increasing rates, the geometric structure and the pressure-increasing operation parameters of the pressure-increasing bin can be optimized, and the stability of powder flowing under the high-pressure environment is ensured.)

1. The utility model provides a be suitable for gas permeability and stress measurement device of powder under high-pressure environment which characterized in that: comprises a silo cylinder (8), an upper end enclosure (5) arranged at the upper end of the silo cylinder (8), an ear type support (6) arranged at the middle section of the silo cylinder (8) and a lower end enclosure (9) arranged at the lower end of the silo cylinder (8);

the upper sealing head (5) is provided with a feed inlet (1), a pressure gauge (2), a safety valve (3) and an upper vent hole (4) which are communicated with the inner cavity of the upper sealing head (5); and a lower vent hole (10) and a discharge hole (11) which are communicated with the inner cavity of the lower end enclosure (9) are arranged on the lower end enclosure (9).

2. The apparatus of claim 1, wherein the apparatus is adapted for measuring gas permeability and stress of the powder under high pressure, and further comprises: the wall surfaces of the bin cylinder (8) and the lower end enclosure (9) are provided with sensors (7) from top to bottom, and the sensors (7) are communicated with the inner cavities of the bin cylinder (8) and the lower end enclosure (9); the sensor (7) consists of a stress sensor and an air pressure sensor.

3. The apparatus of claim 2, wherein the apparatus is adapted for measuring gas permeability and stress of the powder under high pressure, and further comprising: the sensor (7) can respectively and simultaneously measure the gas pressure and the powder stress of each measuring point; according to the penetration rate and the pressure attenuation rule of the gas in the pressurizing process and the stress evolution rule of the powder, the acceleration characteristic of the powder layer particles under different depths and pressures and the mechanism of powder consolidation and compression are disclosed.

4. The apparatus of claim 2, wherein the apparatus is adapted for measuring gas permeability and stress of the powder under high pressure, and further comprising: the shearing device (14) is used for replacing the lower end socket (9) during shearing experiments; the shearing device (14) comprises a flange blind plate (13) abutting against the silo barrel (8) and a stress shearing box (12) arranged on the flange blind plate (13). Feeding and pressurizing after the lower end enclosure (9) is replaced by the shearing device (14), placing the shearing box with the powder in a shearing instrument after pressure relief for carrying out a shearing characteristic experiment, and obtaining the flowing characteristic of the pressurized powder and the change rule of the powder at different depths and different pressures.

5. An experimental method for measuring gas penetrability and stress of powder in a high-pressure environment is characterized by comprising the following steps: the method comprises the gas penetration characteristic of the powder, the stress measurement process of the powder and the shearing characteristic experiment process of the powder.

The gas penetration characteristic of the powder and the stress measurement process of the powder comprise the following steps:

a. closing all valves, opening the feed inlet (1) after checking the air tightness of the experimental device, adding powder materials into the experimental device to a specified position, closing the feed inlet (1) after feeding is finished, checking and keeping the device sealed;

b. opening a data acquisition instrument connected with the sensors (7) to obtain wall surface stress and gas pressure at the measuring points of the sensors in an initial state;

c. setting the inflation rate and inflation pressure of gas entering the upper vent hole (4) and the lower vent hole (11) through a mass flowmeter, and conveying the gas into the experimental device until the set pressure is reached;

d. recording data of each sensor from an initial state to the end of pressurization;

e. after the discharging is finished, the upper vent hole (4) is used for pressure relief.

The experimental process of the shearing property of the powder comprises the following steps:

A. replacing a lower end socket (9) at the lower end of the material bin (8) with a shearing device (14), closing all valves, checking the air tightness of the experimental device, loading a stress shearing box (12) at a preset position by using a support, opening the feeding hole (1), adding powder materials into the experimental device to a specified position, and closing the feeding hole (1) to seal the experimental device;

B. setting the inflation speed and inflation pressure of the air entering the upper vent hole (4) through a mass flowmeter, and conveying gas into the experimental device until the set pressure is reached;

C. after the numerical value of the pressure gauge (2) is stabilized for a period of time, the pressure is relieved by using the upper vent hole (4) until the pressure is consistent with the atmospheric environment pressure;

D. and (3) removing the flange blind plate (13), taking out the stress shear box (12), and placing the stress shear box in a matched shear apparatus to perform a shear characteristic experiment on the powder to obtain shear characteristic parameters of the pressurized powder.

Technical Field

The invention relates to the field of gas pressure change characteristics and powder stress measurement in pressurization of a sealed environment, in particular to a gas penetrability and stress measurement device and an experimental method suitable for powder in a high-pressure environment.

Background

The large-scale high-efficiency coal gasification technology is one of the important fields of the research on the high-efficiency clean utilization of coal. The high-pressure powder supply system is a component of the core technology of the dry coal powder gasification process. The high-pressure bin is connected with the normal-pressure powder supply system and the high-pressure feeding system and is core equipment of the high-pressure gasification coal supply system. The high-pressure storage bin needs frequent coal powder inlet and outlet and air pressure lifting in the working process, the working environment is complex and changeable, the reliability of equipment and the stability of discharging are poor, the gasifier is easy to jump, and the safety and the stability of the operation of the gasifier and the continuity of subsequent product production are seriously influenced. The damage and unsmooth blanking of the high-pressure bunker become one of the serious problems affecting the safe and stable production of the coal chemical industry. Therefore, the characteristic change and the rule of the pulverized coal in the bunker under the high-pressure environment are one of the key problems for researching pulverized coal gasification.

The gas penetration and powder consolidation process in the pressurizing process of the high-pressure storage bin is complex, the dynamic evolution mechanism of powder stress in the discharging process is variable, and a material arch is easy to form, so that the discharging is stopped, and the equipment is damaged. The arching mechanism of the powder in the high-pressure bin is closely related to gas penetration, powder stress consolidation and powder stress evolution in the pressurizing process. At present, the reference data and experience of gas penetration and powder stress evolution characteristics of a high-pressure stock bin in the operation process are few, and no mature theory can be referred to, so that a complete scheme for powder stable flowing in a high-pressure environment cannot be formed due to the lack of basic theory and key technical parameters in the theoretical research, engineering design and operation process of a high-pressure system, and the measurement and characteristic research of the high-pressure powder penetration and stress is necessary.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the invention aims to solve the defects in the prior art, and provides a device capable of performing gas penetration and stress measurement on powder in a high-pressure environment, so as to obtain the powder flow and consolidation characteristics of the powder under different pressurizing conditions.

The technical scheme of the invention is as follows: the gas penetrability and stress measuring device and the experimental method suitable for the powder under the high-pressure environment comprise a feed bin cylinder, an upper end enclosure arranged at the upper end of the feed bin cylinder, an ear type support arranged at the middle section of the feed bin cylinder and a lower end enclosure arranged at the lower end of the feed bin cylinder;

the upper end enclosure is provided with a feed inlet, a pressure gauge, a safety valve and an upper vent hole which are communicated with the inner cavity of the upper end enclosure; and the lower end enclosure is provided with a lower vent hole and a discharge hole which are communicated with the inner cavity of the lower end enclosure.

Further, sensors are arranged on the wall surfaces of the bin cylinder and the lower end socket from top to bottom, and the sensors are communicated with the inner cavities of the bin cylinder and the lower end socket; the sensor consists of a stress sensor and an air pressure sensor.

Further, the sensor can respectively measure the gas pressure and the powder stress of each measuring point simultaneously; according to the penetration rate and the pressure attenuation rule of the gas in the pressurizing process and the stress evolution rule of the powder, the acceleration characteristic of the powder layer particles under different depths and pressures and the mechanism of powder consolidation and compression are disclosed.

Further, the device also comprises a shearing device for replacing the lower end socket during a shearing experiment; the shearing device comprises a flange blind plate butted with the silo cylinder and a stress shearing box arranged on the flange blind plate. Feeding and pressurizing after the lower end enclosure (9) of the shearing device is replaced, placing the shearing box with the powder in a shearing instrument after pressure relief for carrying out a shearing characteristic experiment, and obtaining the flowing characteristic of the pressurized powder and the change rule of the powder at different depths and under different pressures

The invention also discloses an experimental method for measuring the gas penetrability and the stress of the powder in the high-pressure environment, which comprises the experimental processes of the gas penetrability, the stress and the shearing property of the powder;

the gas penetration characteristic of the powder and the stress measurement process of the powder comprise the following steps:

a. closing all valves, opening a feed inlet after checking the air tightness of the experimental device, adding powder materials into the experimental device to a specified position, closing the feed inlet after feeding, checking and keeping the device sealed;

b. opening a data acquisition instrument connected with the sensors to obtain wall surface stress and gas pressure at the measuring point of each sensor in an initial state;

c. setting the inflation rate and inflation pressure of gas entering the upper vent hole and the lower vent hole through the mass flowmeter, and conveying the gas into the experimental device until the set pressure is reached;

d. recording data of each sensor from an initial state to the end of pressurization;

e. and after the discharging is finished, the upper vent hole is used for pressure relief.

The experimental process of the shearing property of the powder comprises the following steps:

A. replacing the lower end socket of the lower end of the storage bin cylinder with a shearing device, closing all valves, checking the air tightness of the experimental device, loading a stress shearing box at a preset position by using a support, opening a feed port, adding a powder material into the experimental device to a specified position, and closing the feed port to seal the experimental device;

B. setting the inflation speed and inflation pressure of the air entering the upper vent hole through the mass flowmeter, and conveying gas into the experimental device until the set pressure is reached;

C. after the numerical value of the pressure gauge is stabilized for a period of time, the pressure is released by using the upper vent hole until the pressure is consistent with the atmospheric environment pressure;

D. and (4) removing the flange blind plate, taking out the stress shearing box, and placing the stress shearing box in a matched shearing instrument to perform shearing characteristic experiment on the powder to obtain shearing characteristic parameters of the pressurized powder.

Has the advantages that:

compared with the prior art, the invention has the beneficial effects that:

1. the experimental device can simultaneously obtain the powder stress and the gas pressure at different testing positions in a high-pressure closed environment, so that the powder stress and gas pressure change rules at different depth measuring points in the pressurizing process can be known, the compression characteristic of the powder along the radial direction, the particle acceleration characteristic and the consolidation rule in the powder layer can be further mastered, and the influence rule of pressurizing and standing on the powder basic flow mechanics characteristic can be disclosed.

2. The gas penetration position of powder in the existing high-pressure bin is not easy to measure, consolidation is easy to occur, the pressurizing parameter is difficult to accurately adjust, and subsequent discharging is not facilitated. The device can obtain gas pressure at different positions through the sensor, if the gas pressure exists in the measuring point close to the vent hole direction and does not exist in the measuring point far away from the vent hole direction, the measuring point is indicated as a penetrating position, and the gas pressure or the inflation speed of the upper vent hole and the lower vent hole is adjusted to completely penetrate through the powder, so that the consolidation problem is solved, and the discharging is facilitated.

3. At present, the compression characteristic of powder under a high-pressure environment is difficult to obtain under the sealing condition of a high-pressure bin. The device can be pressurized to make the pressure in the bin from the atmospheric pressure p₀Increase to p₁According to powder stress analysis of sensors at different positions, if no powder stress exists at a measuring point close to the upper vent hole of one measuring point and the powder stress exists at the sensor at the measuring point below the measuring point, the measuring point is the upper end position of the powder, and the distance between the measuring point and a discharge hole of a lower end enclosure is recorded as h₀I.e. the height of the powder before compression; after the air hole is filled into the bin to form a high-pressure environment, the upper end position of the powder is measured by the same method, and the distance between the upper end position and the discharge hole of the lower end enclosure is recorded as h₁I.e. the height of the powder after compression. From this, the compression characteristic characterization coefficient of a specific powder can be obtained

4. The basic mechanical properties of the powder in the high-pressure bin change after being compressed by high-pressure gas, and the existing shearing experiment is the powder under the normal pressure state, so that the flowability of the powder under the high-pressure environment cannot be accurately analyzed to ensure smooth discharging. This device can be with high-pressure feed bin lower extreme conic section part change straight flange, can place stress shear box at arbitrary height through the support, places stress shear box after the pressurization and carry out the shearing experiment on shearing the appearance, according to the shearing characteristic of different positions powder, can obtain the powder flow characteristic and the change law under the different degree of depth, different pressurization speed and different pressure.

5. The device is provided with an upper air vent and a lower air vent simultaneously, the inflation speed and the inflation proportion of the upper air vent and the lower air vent can be adjusted, the influence of different pressurization parameters on the powder penetration and stress states is revealed, and the powder penetration state and the stress state under different pressurization conditions are obtained, so that the pressurization mode with minimum consolidation stress and better powder flowability is selected.

Drawings

FIG. 1 is an overall block diagram of the present invention;

fig. 2 is a schematic view of the installation state of the silo cylinder and the shearing device in the invention.

Wherein the reference numerals are: 1-a feed inlet, 2-a pressure gauge, 3-a safety valve, 4-an upper vent hole, 5-an elliptical seal head,

6-ear type support, 7-wall sensor, 8-silo cylinder, 9-conical seal head, 10-lower vent hole, 11-discharge hole,

12-stress shear box, 13-flange blind plate, 14-shearing device

Detailed Description

For the understanding of the present invention, the present invention will be described in detail with reference to the accompanying drawings, which are provided for the purpose of illustration only and are not intended to limit the scope of the present invention.

As shown in fig. 1-2, in the gas penetrability and stress measurement device suitable for powder under a high-pressure environment, the sealing gasket is laid on the top of the bin 8 and fastened with the upper end enclosure 5 through bolts, and the sealing gasket is laid on the bottom of the bin 8 and fastened with the lower end enclosure 9 through bolts. The external valve of the feed inlet 1 is connected with a feeding device, the external valve of the discharge outlet 11 is connected with a pressure-resistant material receiving tank, the external valves of the upper vent hole 4 and the lower vent hole 10 are connected with an air supply source, and the air tightness of the experimental device is ensured when all the valves are closed.

The gas penetration and stress measurement experiment of the powder comprises the following specific operation steps: adding materials into the bin cylinder 8 by opening the feed inlet 1, closing the valve after the feeding is finished, checking and keeping the device sealed; opening the data acquisition instrument of the wall sensor 7; adjusting the inflation speed, inflation pressure and proportion of the upper vent hole 4 and the lower vent hole 10 through a mass flow controller to convey gas into the storage bin until a set value is reached; the data acquisition instrument of the wall sensor 7 simultaneously records the powder stress and the gas pressure of a measuring point in the discharging process; after the discharging is finished, the pressure is released through the upper vent hole 4.

When the shearing characteristic of the high-pressure powder is measured, the sealing gasket is laid on the top of the bin cylinder 8 and is tightly connected with the upper end enclosure 5 through bolts, the lower end enclosure 9 at the lower end of the bin cylinder 8 is replaced by the shearing device 14, the sealing gasket is laid on the bottom of the bin cylinder 8 and is tightly connected with the flange blind plate 13 through bolts, and the stress shearing box 12 can be arranged at any height position in the bin cylinder 8 through a support and is used for loading the powder in a high-pressure environment. And releasing pressure after a stable high-pressure environment is formed, placing the shearing box with the powder in a shearing instrument for a shearing experiment to obtain the mechanical characteristics of the powder in the high-pressure environment, and analyzing the law according to different depths and different pressures.

The specific operation of the shearing experiment is as follows: the external valve of the feed inlet 1 is connected with the feeding device, the external valve of the upper vent hole 4 is connected with the air supply source, and the air tightness of the experimental device is ensured when all the valves are closed. Opening the feed port 1, adding a powder material into the experimental device to a preset position of a stress shear box 12, loading the stress shear box 12, continuously feeding the material to a specified position, and closing the feed port 1 after the feeding is finished so as to seal the feed port; controlling the parameters of the gas in the upper vent hole 4 through a mass flow rate controller and inflating the cabin until the set pressure is reached; after the numerical value of the pressure gauge 2 is stabilized for a period of time, the pressure is relieved by using the upper vent hole 4 until the pressure is consistent with the atmospheric environment pressure; the shearing device 14 is removed, the stress shear box 12 is removed, and the powder shear property test is carried out in a matched shearing instrument.

The invention comprises a high-pressure powder penetration and stress measurement experimental method, which is based on a device shown in figure 1 and specifically comprises the following steps:

1. closing all valves, opening the feed port 1 after checking the air tightness of the experimental device, adding powder materials into the experimental device to a specified position, and closing the feed port 1 after feeding to keep the device sealed;

2. opening a data acquisition instrument connected with the wall surface sensor 7 to obtain powder stress and gas pressure at the measuring point of each sensor;

3. setting the inflation speed, inflation pressure and upper and lower proportion of an upper vent hole 4 and a lower vent hole 11 through a mass flowmeter, and conveying gas into the experimental device until the set pressure is reached;

4. analyzing the gas pressure value of each measuring point to obtain the penetration characteristic of the gas to the powder material under the pressure and the change rule of the gas pressure at each measuring point;

5. analyzing the wall surface stress value of each measuring point to obtain the compression characteristic of the powder material under the pressure and the wall surface stress change rule at each measuring point in the pressurizing process;

6. recording sensor data from an initial state to the end of pressurization;

7. after the discharging is finished, the upper vent hole 4 is used for pressure relief.

In step 3, the powder stress and the gas pressure can be obtained simultaneously through the wall sensor 7, and the following analysis results are obtained: the characteristics of gas penetration in the pressurizing process, the acceleration of particles in the powder and along the wall, the mechanism and characteristics of powder compression and consolidation and other mechanical rules.

In the step 3, different inflation speeds and inflation pressure ratios of the upper vent hole 4 and the lower vent hole 11 can be set, and consolidation and flow characteristics of the powder under different inflation speeds and different inflation pressures are researched.

The invention also comprises a high-pressure powder shearing characteristic experimental method, which is based on the device shown in figure 1, and figure 2 shows a partial sectional view of the device, and specifically comprises the following steps:

1. after the shearing device 14 replaces the lower end enclosure 9, all valves are closed, and the air tightness of the experimental device is checked; loading the stress shear box 12 to a preset position by using a bracket, opening the feed port 1, adding a powder material to the experimental device to a specified position, and closing the feed port 1 after feeding is finished so as to keep the device sealed;

2. the ventilation flow and pressure of the upper ventilation hole 4 are set through the mass flowmeter, and gas is conveyed into the experimental device until the set pressure is reached;

3. after the numerical value of the pressure gauge 2 is stabilized for a period of time, the pressure is relieved by using the upper vent hole 4 until the pressure is consistent with the atmospheric environment pressure;

4. the shearing device 14 is removed, the stress shear box 12 is taken out, and the powder shear characteristic test is carried out in a matched shearing instrument.

The internal friction coefficient and the adhesive force of the powder can be known in subsequent tests of a matched shearing instrument so as to evaluate the flowability of the powder.

The device can be used for testing powder in different depths and different pressure environments, and analyzing the flow characteristics and rules of the powder in different depths and different pressures in the storage bin.

The invention also includes a method for improving the discharge of the measuring device, the method comprising:

and analyzing according to the gas pressure at different positions, if the sensor 7 of any measuring point close to the measuring point in the direction of the vent hole at the upper end of the measuring point has gas pressure and the measuring point far away from the vent hole has no gas pressure, the penetrating position is at the measuring point, and the gas parameters and the proportion of the upper vent hole and the lower vent hole are adjusted at the moment to ensure that the powder is completely penetrated, thereby solving the consolidation problem and facilitating discharging.

Because the compression characteristic of the powder cannot be obtained under the sealing condition of the existing high-pressure silo. The invention also comprises a powder compression characteristic detection method suitable for the measuring device, which comprises the following steps of measuring and calculating the compression characteristic characterization coefficient of the powder:

adding the materials from the feed inlet 1, pressurizing to make the pressure in the bin from the atmospheric pressure p₀Increase to p₁According to powder stress analysis of the sensors 7 at different positions, if the measuring points of one measuring point close to the upper vent hole direction have no powder stress, and the sensors of the measuring points below the measuring point have powder stress, the measuring point is the upper end position of the powder, and the distance between the measuring point and the discharge hole of the lower end enclosure is recorded as h₀I.e. the height of the powder before compression; after the air hole is filled into the bin to form a high-pressure environment, the upper end position of the powder is measured by the same method, and the distance between the upper end position and the discharge hole of the lower end enclosure is recorded as h₁I.e. the height of the powder after compression. From this, the compression characteristic characterization coefficient of a specific powder can be obtained

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are intended to further illustrate the principles of the invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention, which is also intended to be covered by the appended claims. The scope of the invention is defined by the claims and their equivalents.