CN104914006B - A kind of experimental provision and experimental method for being used to measure bulk solid flowing law in the silo - Google Patents

Abstract

The invention discloses an experimental device for measuring the flow law of granular bodies in a silo, which has a support mechanism, a silo main body arranged on the support mechanism, and a supply mechanism for supplying granular bodies to the silo main body; The main body of the silo is composed of front and rear plexiglass retaining walls and rear plexiglass retaining walls, left and right panels on both sides, and a discharge mechanism at the bottom; the positive plexiglass retaining wall is provided with a scale line Ⅰ, The rear plexiglass retaining wall is equipped with strain gauges for monitoring the pressure changes at various points on the plexiglass retaining wall during the flow of granular materials. Both the positive plexiglass retaining wall and the rear plexiglass retaining wall are transparent plexiglass plates. The flow law of the bulk in the silo can be studied intuitively and conveniently, so as to avoid the phenomenon that the field test is restricted by conditions such as site, equipment and personnel safety, resulting in inaccurate measurement data.

Description

An experimental device and experiment for measuring the flow law of granular materials in silos method

technical field

The invention belongs to the field of testing the flow law of granular bodies in underground mining ore-drawing and silo loading and unloading processes, and in particular relates to an indoor experimental device and method for testing the moving zone range and side wall pressure during the flow process of silo granular bodies .

Background technique

In recent years, with the continuous development of bulk material storage and transportation in the direction of fast, quantitative and accurate, silos and hoppers have been widely used in metallurgy, chemical industry, coal, grain and other industries. Many problems have also been found during use, such as the blockage of the discharge port by the particles, the wear and tear on the silo wall, etc. In order to study the above problems, it is necessary to understand the flow characteristics of bulk materials. Since its flow is more complicated than that of liquid and solid, its in-depth study is of great significance for practical applications.

When the actual silo is unloading, it is difficult to describe whether the flow pattern of the material is a single type or a mixture of several types, using traditional theories. In addition, the force exerted by the material on the silo during the movement is completely different from that when it is in a static state. Different, so the pressure problem of the material in the silo is very complicated, and its initial state and flow conditions are different. Even if a very small amount of material is discharged, the pressure on the silo wall also increases, even 1 at the time of static pressure. ~2 times. The discharge form of the silo is different, and the value of the pressure increase of the silo wall is also different. As for the mechanism of dynamic pressure, scholars from various countries have different opinions. In the early days, there were the theory of changes in storage properties and dynamic arching, which can explain some phenomena, but no calculation theory has been formed.

At present, the research on the flow law of silo bulk body mainly uses three methods: empirical formula, field test and numerical simulation. However, a large number of practices have proved that the empirical formula method (Janssen formula) is quite different from the actual test results, and even some calculations are contrary to engineering phenomena; field tests are restricted by conditions such as site, equipment and personnel safety (especially large chute and large tube warehouse), it is often difficult to conduct on-site operations, and the results are highly discrete, so it is not suitable for analysis and research; numerical simulation is the main means of utilization at the present stage, but due to the friction coefficient between particles and between particles and the well wall is difficult Therefore, the results can only be used for qualitative analysis and cannot be used as the main basis for design.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention proposes an experimental device and an experimental method for measuring the flow law of the granular body in the silo, which can intuitively and conveniently study the flow law of the granular body in the silo, so as to avoid on-site The test is restricted by conditions such as site, equipment and personnel safety, resulting in inaccurate measurement data.

The technical scheme adopted in the present invention is:

An experimental device for measuring the flow law of granular bodies in a silo, which has a support mechanism, a silo main body arranged on the support mechanism, and a supply mechanism for supplying granular bodies to the silo main body; the silo The main body of the warehouse is composed of front and rear plexiglass retaining walls and rear plexiglass retaining walls, left and right panels on both sides, and a discharge mechanism at the bottom; the positive plexiglass retaining wall is provided with a scale line I , the rear plexiglass retaining wall is provided with strain gauges for monitoring the pressure changes at various points on the plexiglass retaining wall during the flow of granular materials, and the positive plexiglass retaining wall and the rear plexiglass retaining wall are transparent organic glass plate.

The described experimental device for measuring the flow law of granular materials in the silo, the support mechanism includes a table top, and the table legs used to support the table top are arranged on the table top to support the positive organic glass retaining wall and the rear organic glass wall. The triangular support plate of the glass retaining wall is provided with a leak on the desktop. The unloading mechanism includes two symmetrical bottom plates. The two bottom plates are respectively slidingly fitted with the left side plate and the right side plate. The length of the bottom plate is the same as the length from the edge of the leak to the edge of the desktop.

The described experimental device for measuring the flow law of granular materials in a silo has a leak switch at a position corresponding to the leak under the desktop, and the leak switch is a pull-out switch structure. The desktop is provided with a scale line II along the direction of the bottom plate.

The described experimental device for measuring the flow law of granular bodies in a silo, the feeding mechanism has a conveyor belt, and the driving belt is divided into a lifting part located under the unloading mechanism for recovering granular bodies, and the lifting part The granular material is transferred to the transfer section in the horizontal position, and the horizontal transport section is used to transport the granular material horizontally to the main body of the silo.

The described experimental device for measuring the flow law of granular bodies in the silo, the feeding mechanism also includes a uniform filling device, and the uniform filling device includes an inclined buffer plate located on the upper part of the silo main body, and the inclined buffer The top of the flat plate is provided with an arc-shaped guide rail, the two sides of the inclined buffer flat plate are provided with limit plates, and the top of the inclined buffer flat plate is provided with a rotating cylinder. The lower part of the rotary cylinder is the moving end of the output granular body, and the lower part of the rotating cylinder is equipped with a slider with adjustable speed, and the slider is movably connected with the arc guide rail.

In the said experimental device for measuring the flow law of granular materials in the silo, the width of the inclined buffer plate is the same as that of the plexiglass retaining wall.

The described experimental device for measuring the flow law of granular materials in the silo, the two sides of the inner side wall of the left side plate and the right side plate are respectively provided with a front plexiglass retaining wall and a rear plexiglass Cutting slots for retaining walls I.

In the aforementioned experimental device for measuring the flow law of granular materials in a silo, the distance between adjacent scale marks I is 50 mm, and the distance between adjacent strain gauges is 90 mm.

The above-mentioned experimental device for measuring the flow law of the granular body in the silo, the top of the silo main body is provided with a funnel.

A test method for measuring the flow law of granular materials in silos, comprising the following steps:

1) Turn off the leak switch to block the leak on the desktop;

2) Initial loading, manual loading to a certain height, to ensure the overall flow of the upper part of the main body of the silo during the flow of granular materials;

3) Connect the strain gauge and start monitoring the pressure change on the rear plexiglass retaining wall;

4) Start the feeding mechanism, open the unloading mechanism at the bottom of the silo main body to start unloading, and the outflowing granular materials are transported back to the silo main body through the feeding mechanism to realize circulation;

5) When the cycle is stable, draw the moving range of the granular particles during the unloading process on the positive plexiglass retaining wall.

The present invention has the following beneficial effects:

1. The present invention is an experimental device for measuring the flow law of granular materials in silos, which includes three parts, namely support mechanism, silo main body and feeding mechanism. The three parts can be separated freely for easy disassembly and assembly , carrying and maintenance, to meet the experimental needs. The front plexiglass retaining wall and the rear plexiglass retaining wall of the main body of the silo are both transparent plexiglass plates, which is convenient for observing the flow state of the granular body inside the silo main body, and at the same time, the granular material can be drawn according to the scale line Ⅰ of the positive plexiglass retaining wall According to the strain gauge of the rear plexiglass retaining wall, monitor the change of pressure at each point on the rear plexiglass retaining wall during the flow of granular particles. The device can draw the range of the moving zone during the flow of granular materials; it can test the pressure at each measuring point on the wall of the main body of the silo in real time; it is convenient for the measurement and research of the flow law of the granular materials in the silo, At the same time, the transparent plexiglass plate is used as the retaining wall, so that the flow of the granular body can be observed clearly at close range, and the experimental effect can be more clear due to the existence of the scale line.

2. The unloading mechanism includes two symmetrical bottom plates. The two bottom plates are slidingly matched with the left side plate and the right side plate respectively. The unloading mechanism 4 corresponds to the leak. The length of the bottom plate is the same as the length from the edge of the leak to the edge of the desktop. The size of the discharge opening in the discharge mechanism at the bottom of the silo can be changed to facilitate testing the flow law of granular materials under different experimental conditions.

3. The feeding mechanism has a conveyor belt, and the transmission belt is divided into a lifting part located under the unloading mechanism for recovering the granular body, a transfer part for transferring the granular body in the lifting part to a horizontal position, and a horizontal transportation part for the granular body The horizontal transport section to the main body of the silo. The feeding mechanism realizes the automation of the whole loading and unloading process, and improves the efficiency and effect of the experiment.

4. The uniform filling device in the feeding mechanism makes the charging process realize the overall uniform charging, and the charging speed can be adjusted. The slider moves back and forth at a constant speed on the arc-shaped guide rail, and the moving speed can be adjusted to realize the left-right uniformity of the loading process above the main body of the silo.

Description of drawings

Fig. 1 is a schematic diagram of the front view of an experimental device for measuring the flow law of granular bodies in a silo according to the present invention.

FIG. 2 is a schematic top view of the experimental device shown in FIG. 1 .

Fig. 3 is a front structural schematic diagram of the silo mechanism in the present invention.

Fig. 4 is a left view structural schematic diagram of the silo mechanism in the present invention.

Fig. 5 is the scale line on the plexiglass retaining wall in the silo mechanism of the present invention.

Fig. 6 is the strain gauge on the plexiglass retaining wall in the silo mechanism of the present invention.

Fig. 7 is a front structural schematic view of the supporting mechanism of the present invention.

Fig. 8 is a schematic bottom view of the supporting mechanism of the present invention.

Fig. 9 is a schematic diagram of the assembly structure of the present invention.

Fig. 10 is a structural schematic diagram of the feeding mechanism of the present invention.

Fig. 11 is a schematic front view of the uniform filling device in the feeding mechanism.

Fig. 12 is a left view structural schematic diagram of the uniform filling device in the feeding mechanism.

Among them, 1-silo main body, 2-supporting mechanism, 3-feeding mechanism, 4-discharging mechanism, 5-hopper, 6-positive plexiglass retaining wall, 7-right side plate, 8-cutting groove II, 9 -cutting slot Ⅰ, 10-scale line Ⅰ, 11-strain gauge, 12-triangular support plate, 13-table leg, 14-table top, 15-leakage, 16-leakage switch, 17-scale line Ⅱ, 18- Conveyor belt, 19-uniform filling device, 20-lifting part, 21-transfer part, 22-horizontal transport part, 23-rotating cylinder, 24-curved guide rail, 25-slider, 26-inclined buffer plate, 27-limit Bit board, 28-fixed end, 29-mobile end.

detailed description

As shown in the figure, an experimental device for measuring the flow law of granular materials in a silo has a supporting mechanism 2, a silo main body 1 arranged on the supporting mechanism 2, and is used for supplying granular materials to the silo main body 1 The supply mechanism 3 of the body; the three parts of the silo main body 1, the support mechanism 2 and the supply mechanism 3 can be separated freely. The silo main body 1 is composed of front and rear plexiglass retaining walls 6 and rear plexiglass retaining walls, left and right panels 7 on both sides, unloading mechanism 4 at the bottom, left and right panels The two sides of the inner wall of 7 are respectively provided with cutting grooves I9 for installing the positive plexiglass retaining wall 6 and the rear plexiglass retaining wall. The plate 7 is slidingly fitted, and there is a cutting groove II8 under the left and right plate 7, the width of the cutting groove II8 matches the width of the bottom plate, and the bottom plate cooperates with the cutting groove II8 and is slidingly connected with the left side plate/right side plate 7 . The positive plexiglass retaining wall 6 is provided with a scale line I10, and the rear plexiglass retaining wall is provided with a strain gauge 11 for monitoring the pressure change of each point on the plexiglass retaining wall during the flow of granular materials, and the distance between adjacent scale lines I10 50mm, the distance between adjacent strain gauges 11 is 90mm, and the positive plexiglass retaining wall 6 and the rear plexiglass retaining wall are transparent plexiglass plates. The top of the silo main body 1 is provided with a funnel 5 .

Support mechanism 2 comprises desktop 14, with the table leg 13 of supporting desktop 14, is arranged on the desktop 14 and is used to support the triangular support plate 12 of positive plexiglass retaining wall 6 and rear plexiglass retaining wall, and the desktop 14 is provided with leak 15 , the discharge mechanism 4 at the bottom of the silo main body 1 corresponds to the leak opening 15. Preferably, for the convenience of setting the size of the discharge opening, the length of the bottom plate is equivalent to the distance from the edge of the table leak opening to the table boundary. A leak switch 16 is provided at the position corresponding to the leak 15 under the desktop 14. The leak switch 16 is a leak switch device based on the drawer principle. The table 14 is provided with a scale line II 17 along the direction of the bottom plate to cooperate with the bottom discharge of the silo. The use of the bottom plate in the mechanism realizes the size change of the discharge port by adjusting the scale value.

Feeding mechanism 3 has conveyer belt 18, and conveyer belt 18 is divided into and is positioned at unloading mechanism 4 below and is used for reclaiming the lifting part 20 of granular body, the granular body of lifting part 20 is transferred to the transshipment part 21 of horizontal position, and is used for The granular material is transported horizontally to the horizontal transport section 22 of the silo main body 1 . The feeding mechanism 3 also includes a uniform filling device 19, and the uniform filling device 19 includes an inclined buffer plate 26 positioned at the top of the silo main body 1. The top of the inclined buffer plate 26 is provided with an arc-shaped guide rail 24, and the both sides of the inclined buffer plate 26 A limit plate 27 is provided, and a rotating cylinder 23 is provided above the inclined buffer plate 26. The upper part of the rotating cylinder 23 is a fixed end 28 for receiving the granular body inlet, and the lower part of the rotating cylinder is a moving end for outputting the granular body outlet. 29. The lower part of the rotating cylinder 23 is equipped with a slider 25 with adjustable speed. The slider 25 is movably connected with the arc guide rail 24. The moving end 29 is fixed with the slider 25 and moves together with the slider 25. The slider 25 It can move back and forth at a constant speed on the arc-shaped slide rail 24, and the moving speed can be adjusted to realize the left and right uniformity of the charging process. The width of the inclined buffer plate 26 is consistent with the width of the plexiglass retaining wall. During the experiment, the assembly was carried out according to the following steps: first, the three parts of the silo main body 1, the support mechanism 2 and the supply mechanism 3 were respectively installed; the leak switch 16 in the support mechanism was closed to block the leak 15 of the desktop. To install the silo main body 1, install the bottom discharge structure 4 first, adjust the size of the discharge opening through the scale line Ⅱ17, then install the rest, and finally assemble the feeding mechanism.

A test method for measuring the flow law of granular materials in silos,

The specific operation steps are as follows:

(1) close the leak switch 16 to block the leak 15 of the desktop;

(2) Initial loading, manual loading to a certain height, to ensure the overall flow of the upper part of the silo during the flow of the bulk, because the volume of the conveyor belt part needs to be reserved, so more materials should be added on this basis;

(3) connect the strain gauge 11, and start monitoring the pressure change on the rear plexiglass retaining wall;

(4) Start the feeding mechanism 3, open the unloading mechanism 4 at the bottom of the silo main body 1 to start unloading, and the outflowing granular body is transferred back to the silo main body 1 by the feeding mechanism 3 to realize circulation;

(5) Open the leak switch 16 and start unloading, and the outflowing bulk flows back in the silo 1 by the automatic loading and unloading device 3 to realize circulation;

(6) When the cycle is stable, draw the moving zone range of the granular body during the unloading process on the positive plexiglass retaining wall 6 .

Claims (8)

1. a kind of experimental provision for being used to measure bulk solid flowing law in the silo, it is characterised in that with supporting mechanism (2) the silo main body (1) on supporting mechanism (2), is arranged on, and for supplying the feeding machanism of bulk solid to silo main body (1) (3)；The silo main body (1) is by positioned at front and rear positive lucite barricade (6) and rear lucite barricade, the left side positioned at both sides Side plate and right plate (7), the shedding mechanism (4) positioned at bottom are constituted；The positive lucite barricade (6) is provided with graduation mark I (10), the rear lucite barricade, which is provided with, is used to monitor in bulk solid flow process each point pressure on lucite barricade The foil gauge (11) of change, the positive lucite barricade (6) and rear lucite barricade are transparent plexiglass plate；

The feeding machanism (3) has conveyer belt (18), and conveyer belt (18), which is divided into below shedding mechanism (4), to be used to reclaim scattered The lift portion (20) of plastochondria, the bulk solid of lift portion (20) is transferred to the transhipment part (21) of horizontal level, and is used for By the horizontal transport part (22) of bulk solid horizontal transport to silo main body (1)；The feeding machanism (3) also includes uniform filler Device (19), the uniform filler device (19) includes the inclination buffering flat plates (26) positioned at silo main body (1) top, tilts slow The top for rushing flat board (26) is provided with arc-shaped guide rail (24), and the both sides for tilting buffering flat plates (26) are provided with limiting plate (27), tilts slow The top for rushing flat board (26) is provided with rotor (23), and the top of the rotor (23) is the fixing end for receiving bulk solid (28), the bottom of rotor is the mobile terminal (29) of output bulk solid, and the bottom of rotor (23) is equipped with adjustable speed Sliding block (25), the sliding block (25) is flexibly connected with the arc-shaped guide rail (24).

2. a kind of experimental provision for being used to measure bulk solid flowing law in the silo according to claim 1, its feature It is, the supporting mechanism (2) includes desktop (14), for the table leg (13) of supporting desktop (14), is arranged on desktop (14) Gusseted plate (12) for supporting positive lucite barricade (6) and rear lucite barricade, desktop is provided with Lou on (14) Mouth (15), shedding mechanism (4) includes symmetrical two bottom plate, and two bottom plates are slidably matched with left plate and right plate (7) respectively, The shedding mechanism (4) is corresponding with leak (15), length and leak (15) edge to desktop (14) edge of the bottom plate Length is identical.

3. a kind of experimental provision for being used to measure bulk solid flowing law in the silo according to claim 2, its feature It is, the position corresponding with leak (15) is provided with leak switch (16) below desktop (14), and the leak switch (16) is to take out Pull type switch structure, the desktop (14) is provided with graduation mark II (17) along bottom plate direction.

4. a kind of experimental provision for being used to measure bulk solid flowing law in the silo according to claim 1, its feature It is, the width all same of the width for tilting buffering flat plates (26) and positive lucite barricade and rear lucite barricade.

5. a kind of experimental provision for being used to measure bulk solid flowing law in the silo according to claim 1, its feature Be, the both sides of the madial wall of the left plate and right plate (7) be respectively provided with the positive lucite barricade (6) of installation and after The cutting groove I (9) of lucite barricade.

6. a kind of experimental provision for being used to measure bulk solid flowing law in the silo according to claim 1, its feature It is, the spacing of adjacent graduation mark I (10) is 50mm, and the spacing of adjacent foil gauge (11) is 90mm.

7. a kind of experimental provision for being used to measure bulk solid flowing law in the silo according to claim 1, its feature It is, the top of the silo main body (1) is provided with funnel (5).

8. a kind of test method for being used to measure bulk solid flowing law in the silo, using such as any one of claim 1-7 institutes The experimental provision for being used to measure bulk solid flowing law in the silo stated, it is characterised in that comprise the following steps：

1) leak switch (16) is closed to block the leak (15) of desktop；

2) initial charge, feeds to certain altitude, it is ensured that bulk flow occurs in silo body top in bulk solid flow process manually It is dynamic；

3) connection foil gauge (11), starts the pressure change on lucite barricade after monitoring；

4) feeding machanism is started, the shedding mechanism for opening silo bottom part body starts discharging, and the bulk solid of outflow passes through feeding machine Structure is transmitted back in silo main body (1), realizes circulation；

5) stabilization to be recycled, draws the bulk solid moving belt scope in discharge process on positive lucite barricade (6).