JP2763128B2 - Powder flow measurement method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for measuring a flow rate of a granular material for measuring a flow rate of a granular material.

[Related Art] In recent years, the automation of the process has been advanced, and powder and granules, for example, grains such as paddy, wheat, and red beans which are primary agricultural products, or plastic chips, pellets, coke, coal stone, sand, etc. which are industrial and mining products Automation is also being promoted in the field dealing with. For this automated propulsion, various methods are known for measuring the flow rate of these powders. For example, a method of measuring the horizontal component force of an impact load generated when a granular material falls at a certain speed and hits a detection plate by detecting the horizontal component force by using a load detector or a method described in Japanese Patent Application Laid-Open No. 57-18901.
3), a method of measuring the horizontal component force by detecting the same using a Shapin type load cell (JP-A-60-122324),
A method of measuring the same by detecting the horizontal component using a strain gauge attached to a detection shaft (Japanese Patent Laid-Open No. 60-164220) is known.

[Problems to be Solved by the Invention] However, in such a conventional method for measuring the flow rate of a granular material, the granular material is dropped at a certain speed, collides with a detecting plate, and the horizontal component force caused by the falling is detected and detected. From the horizontal component and the relationship between the flow rate and the horizontal component that are determined in advance,
Although the flow rate of the granular material is measured, a frictional force is generated between the granular material and the detection plate when colliding with the detection plate. Also,
When the flow rate of the granular material increases, the granular material flows down without bouncing on the detection plate, and similarly, a frictional force is generated between the granular material and the detection plate. This frictional force differs depending on the water content of the granular material, the particle size of the granular material, and the like. When detecting the horizontal component force and measuring the flow rate, an error is detected in the detected horizontal component force according to the frictional force. This causes a problem that an error occurs in the measurement of the flow rate.

In order to prevent this error, the relationship between the flow rate and the horizontal component must be determined in advance in accordance with the water content of the powder and the particle size of the powder, etc., which requires a great deal of labor. There was a problem that.

Therefore, an object of the present invention is to solve the above-described problems, and to accurately measure the flow rate of a granular material without being affected by a change in frictional force due to the water content of the granular material or the particle size of the granular material. It is an object of the present invention to provide a method for measuring the flow rate of a powdery or granular material.

[Means for Solving the Problems] In order to achieve the object, the present invention has the following configuration as means for solving the problems. That is, when the continuously flowing powder and granular material passes through the inclined gutter, a component force parallel to the gutter and a vertical component force acting on the gutter by the granular material are detected, and the horizontal component is detected. This is a method for measuring the flow rate of the granular material based on the component force and the vertical component force.

[Operation] The method for measuring the flow rate of a powder material is characterized in that, when a powder material that flows continuously passes through an inclined gutter, a component force parallel to the gutter acting on the gutter by the powder material, Component force and
Based on the horizontal component force and the vertical component force, the flow rate of the granular material is measured from a movement that also considers a frictional force generated between the gutter and the granular material. Therefore, the moisture content of the granular material,
It is possible to accurately measure the flow rate of the granular material without being affected by the particle size of the granular material.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a powder flow meter according to one embodiment of the present invention, and FIG. 2 is an enlarged sectional view of AA in FIG. This powder flow meter is provided with a tubular gutter 1 having a square cross-section through which chaff CH as a powder material passes. The gutter 1 is disposed with an inclination angle θ at which the chaff CH can flow down. For example, in the present embodiment, the gutter 1 is disposed with an inclination angle θ of 30 degrees with respect to a horizontal plane. A hopper 2 that opens upward is connected to one upper end of the gutter 1. In addition, the gutter 1 is not limited to a square-shaped cross section, but may be a U-shaped cross section.

An elastic member 3 is disposed on the lower surface of the gutter 1,
In this elastic member 3, two annular annular portions 8, 10 having notches 4, 6 in part are arranged side by side at predetermined intervals so as to oppose the notches 4, 6. The annular portions 8 and 10 are formed to have a small width and a small thickness. Furthermore, notches
Except for 4,6, about 1/4 of the upper side of each annular part 8,10 is connected by the upper connecting part 12 installed on both annular parts 8,10, and similarly, it is installed on both annular parts 8,10. Each annular part by the lower connecting part 14
About 1/4 of the lower side of 8,10 is connected. As described above, the elastic member 3 includes the upper connecting portion 12 and the lower connecting portion
10 are connected to form a continuous continuous loop.

On the other hand, two vertical surfaces of two “L” shaped fixing members 16 are attached to the upper connecting portion 12 of the elastic member 3. The horizontal surface of the fixing member 16 is attached to the lower surface of the gutter 1, and the gutter 1 and the elastic member 3 are integrally formed. Further, the lower connecting portion 14 also has two "L"
The vertical surfaces of the letter-shaped fixing members 18 are respectively attached. The horizontal plane of the fixing member 18 is fixed to a base or the like (not shown).

On the other hand, at the center of the elastic member 3, one ends of the buffer members 20, 22 are fixed to both side surfaces of the lower connecting member. The other ends of the buffer members 20 and 22 are spread outward, and the upper connecting member 1
2 is formed so as to sandwich it from both sides. One end of each of the braking members 24 and 26 is attached to the other end of each of the buffer members 20 and 22, and the other end of each of the braking members 24 and 26 is pressed against the side surface of the upper connecting member 12 respectively. I have. This braking member 24,2
Although a sponge is used in this embodiment as the material of No. 6, for example, felt, rubber, or the like can be used.

Also, through holes 28, 30 are provided at the centers of the buffer members 20, 22, respectively.
A bolt 32 is inserted into the through holes 28 and 30, and a nut 34 is screwed into the bolt 32. By tightening the bolt 32 and the nut 34, the pressure contact force between the braking members 24, 26 and the upper connecting member 12 can be adjusted via the buffer members 20, 22. The buffer members 20, 22, the braking members 24, 26, the bolt 32, and the nut 34 constitute a so-called buffer. As the shock absorber, a so-called oil damper type shock absorber may be provided between the upper and lower connecting members 12 and 14 in addition to the above embodiment.

On the other hand, the one annular portion 8 of the elastic member 3 has a line a passing through the center of the annular portion 8 on its outer periphery and parallel to the inclination of the gutter 1.
The strain gauge R1 is stuck on top. This strain gauge R1
The strain gauge R2 is also attached to the inner periphery of the annular portion 8 on the opposite side to which is attached. Further, a strain gauge R3 is also attached to the other annular portion 10 on its outer periphery and on the line a. A strain gauge R4 is also attached to the inner circumference of the annular portion 10 on the opposite side to which the strain gauge R3 is attached.

Further, the present embodiment is applied to a point on the outer periphery of the annular portions 8 and 10 of the elastic member 3 where no vertical strain is applied to the annular portions 8 and 10 when a vertical load is applied to the elastic member 3, that is, a so-called node point. In the example, parallel component force strain gauges R5, R6, R7, R8 are attached at points at an angle α = 50.4 degrees with respect to the line a, as shown in FIG.

Further, as shown in FIG. 3, a well-known bridge circuit is constituted by the strain gauges R1, R2, R3, and R4.
Due to 40, a constant voltage is applied to one end of the strain gauges R1, R2 and the strain gauges R3, R4. Strain gauge R1, R2
In addition, a change in the voltage at the other end of each of the strain gauges R3 and R4 is amplified by the dynamic strain meter 42 and can be recorded on a recording paper (not shown) of the pen recorder 44. In this embodiment, four strain gauges R1, R2, R3, and R4 are used.
The present invention is not limited to four, and can be implemented by using two strain gauges R1 and R2 and using a dummy resistor for the other. Further, even if a bridge circuit is not configured, any circuit configuration that can detect a change in resistance can be used.

In addition, the third strain gauge R5, R6, R7, R8 for parallel component force
As shown in the figure, a bridge circuit similar to the strain gauges R1, R2, R3, R4 is formed, and a pure parallel component Fx applied to the elastic member 3 can be detected.

Next, the operation of the powder flow meter of the present embodiment will be described by taking as an example the case of measuring the flow rate of chaff CH as powder.

First, when the chaff CH as the granular material is put into the hopper 2, the chaff CH flows from the hopper 2 into the gutter 1, and the chaff CH flowing into the gutter 1 flows down the gutter 1 and passes through the gutter 1. Later, it is discharged outside. As described above, the rice hulls stay on the gutter 1 while flowing down the gutter 1. When the paddy CH is continuously supplied, the weight of the paddy CH staying on the gutter 1 is very small. For example, when 200 kg / h of paddy CH is supplied, the weight of the paddy CH staying on the gutter 1 varies depending on the inclination angle θ of the gutter 1.
To the extent, very slight. However, since the annular portions 8 and 10 have a small width and a small thickness, even a slight compressive force generates elastic strain.

Due to the weight of the paddy CH staying on the gutter 1, the vertical component Fy in the direction orthogonal to the line a according to the weight via the gutter 1.
Acts on the elastic member 3 so that its height is reduced and its length is increased, that is, in the direction in which the annular portions 8 and 10 become elliptical, An elastic strain is generated that elastically deforms in the direction in which the outer periphery extends and the inner periphery in the contracting direction. Due to this elastic strain, the resistance values of the strain gauges R1, R2, R3, R4 attached to the annular portions 8, 10 change according to the amount of elastic strain.
That is, the resistance values of the strain gauges R1, R2, R3, R4 change according to the vertical component force Fy based on the weight of the paddy CH staying on the gutter 1. When the resistance values of the strain gauges R1, R2, R3, R4 change, the voltages at the other ends of the strain gauges R1, R2 and the strain gauges R3, R4 change, and the voltage is amplified by the dynamic strain meter 42, and the pen recorder 44
Is recorded on a recording paper (not shown).

Also, due to the weight of the paddy CH staying on the gutter 1,
Parallel component force in the direction parallel to line a according to weight via gutter 1
Fx acts on the elastic member 3 to generate elastic strain on the elastic member 3. Due to this elastic strain, the resistance value of the parallel component strain gauges R5, R6, R7, R8 attached to the annular portions 8, 10 changes according to the amount of elastic strain. That is, in accordance with the parallel component force Fx based on the weight of the paddy CH staying on the gutter 1, the parallel component strain gauges R5, R6,
The resistance values of R7 and R8 change. When the resistance values of the strain gauges R5, R6, R7, R8 change, the strain gauges R5, R6 and the strain gauges R7, R8
The voltage at the other end changes and the voltage is amplified by the dynamic strain meter 42 and recorded on a recording paper (not shown) of the pen recorder 44.

When detecting the vertical component force Fy and the parallel component force Fx, since the braking members 24 and 26 are in pressure contact with the upper connecting member 12, the vibration generated in the gutter 1 and the elastic member 3 due to disturbance or the like is attenuated. The value of the vibration is superimposed on the value of the elastic strain,
It is easy to read the values of the vertical component Fy and the parallel component Fx from the recorded values recorded in the pen recorder 44.

Next, a method for calculating the flow rate of the paddy CH based on the detected vertical component Fy and parallel component Fx will be described.

Here, as shown in FIG. 4, paddy CH staying in gutter 1
From the mass m, the gravitational acceleration g, the dynamic friction coefficient ν between the gutter 1 and the chaff CH, and the frictional force P, the parallel component F2 and the vertical component F1 acting on the gutter 1 due to the chaff CH staying in the gutter 1 are: , (1) below,
There is the relationship shown in equation (2).

F2 = m · g · sin θ−P = m · g · sin θ−ν · m · g · cos θ = m · g · cos θ · (tan θ−ν) (1) F1 = m · g · cos θ (2) From the equations (1) and (2), the following equation (3) can be obtained.

F2 / F1 = tan θ−ν (3) Further, between the mass m of the paddy CH staying in the gutter 1, the residence time t of the paddy CH, and the flow rate Q of the paddy CH, the following (4) There is an expression relationship.

Q = m / t (4) When the mass m is eliminated from the equations (4) and (2),
The following equation (5) is obtained.

Q = 1 / t × F1 / (g · cos θ) (5) Next, when a motion equation is established for the chaff CH on the gutter 1 having a length of l, the equation is obtained as in the following equation (6).

m · d ² x / dt ² = m · g · cos θ · (tan θ−ν) (6)
The following equation (7) is obtained by integrating this equation (6) with time t, and the following equation (8) is obtained by integrating the following equation (7) with time t. V ₀ is the initial velocity of the chaff CH that has flowed into the gutter 1.

V = g · cosθ · (tanθ -ν) · t + V 0 ... (7) V 2 -V 0 2 = 2 · g · cosθ · l · (tanθ-ν) ... (8)
The following equation (9) is derived from the equation (7), and the following equation (10) is derived from the equation (8).

t = (V−V ₀ ) / g · cos θ · (tan θ−ν) (9) Further, the following equation (11) is obtained by substituting the equation (10) into the equation (9).

Substituting equation (3) into equation (11), the following equation (12)
An equation is derived.

On the other hand, the following equation (13) is obtained by substituting the equation (12) into the equation (5).

Here, if the initial speed V _{0 is set} to zero, that is, the paddy CH
Flows quietly and the initial velocity V ₀ can be ignored, (1
Equation (3) becomes equation (14) below.

Therefore, the flow rate Q _{0 of the} paddy CH is determined by detecting the parallel component F2 and the vertical component F1, that is, the parallel component F2 is equal to the strain gauge R
The vertical component F1 is equal to the parallel component Fx detected by 1, R2, R3, R4, and the vertical component Fy is detected by the parallel component strain gauges R5, R6, R7, R8. Therefore, by detecting the parallel component Fx and the vertical component Fy, the dynamic friction between the gutter 1 and the paddy CH, and the influence of the difference in viscosity due to the difference in the water content of the paddy CH, and the like, Paddy CH flow Q and parallel component Fx,
It is not necessary to determine the relationship between the vertical component force Fy, whatever granular material, it is possible to easily detect the flow rate Q _0.

In the above-described embodiment, the case where the flow rate of the chaff CH is measured based on the acting force of the chaff CH staying in the gutter 1 has been described as an example. , impinges on the trough 1 to fall from the hopper 2 at an initial speed V _0, in consideration also the acting force that acts on the trough 1 by the collision, the case of measuring the flow rate.

First, a change in momentum due to the collision force Fi will be described.
The vertical component force Fi1 acting on the gutter 1 due to the collision force Fi is as follows (1
5) It is obtained by the formula.

_{Fi1 = Q · V 0y (1} + U y / V 0y) ... (15) where, as shown in FIG. 6, V _0y is a component perpendicular to the trough 1 of the initial velocity V _0, U _y is the gutter This is a component perpendicular to the gutter 1 at the velocity U after rebounding after colliding with the gutter 1.

The initial velocity V ₀ is given by the following equation (1), where h is the height at which the chaff CH falls, and h is a coefficient k (0 <k <1) in consideration of air resistance.
6) It is expressed by the equation.

The following equation (17) is obtained from the above equations (15) and (16).

Here, e = U _y / V _0y, which is a so-called restitution coefficient.

The parallel component Fi2 acting on the gutter 1 due to the collision force Fi
Is determined by the following equation (18).

Here, β = U _x / V _0x, which is a coefficient due to friction between the chaff CH and the gutter 1.

Next, the balance of the force on the gutter 1 will be described. The acting force (parallel component F
2, the vertical component F1), the collision force Fi, and the strain gauges R1, R2, R3,
The parallel component Fx detected by R4 and the vertical component Fy detected by the parallel component strain gauges R5, R6, R7, R8 have a relationship represented by the following equations (19) and (20).

Fy = F1 + Fi1 (19) Fx = F2 + Fi2 (20) On the other hand, if the friction at the time of collision between the gutter 1 and the chaff CH is small, β is about 1, and therefore Fi2 = 0. Flow Q
Is obtained as a relational expression of Fx and Fy by the following expression (21).

Q = f (Fx, Fy) (21) Therefore, k is obtained from the particle diameter and the true density of the granular material, and the flow rate Q is calculated using the particle diameter, the true density, the drop height h, and the restitution coefficient e. Can be measured.

As described above, the method for measuring the flow rate of the granular material according to the present embodiment measures the flow rate Q of the chaff CH based on the parallel component Fx based on the acting force of the chaff CH acting on the gutter 1 and the vertical component Fy. I do.

Therefore, according to the powder flow measurement method of the present embodiment,
The flow rate can be measured continuously without obstructing the flow of CH, and the accurate flow rate Q of the granular material can be measured without being affected by the water content of the chaff CH or the grain size of the chaff CH. can do.

As described above, the present invention is not limited to such embodiments at all, and can be implemented in various modes without departing from the gist of the present invention.

[Effects of the Invention] As described in detail above, according to the powder flow meter of the present invention,
The flow rate can be measured continuously without obstructing the flow of the granules, and the flow rate of the granules can be accurately measured without being affected by the water content of the granules or the particle size of the granules. This has the effect that the flow rate can be measured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a powder flow meter as an embodiment to which the method of the present invention is applied, FIG. 2 is an enlarged sectional view of AA in FIG. 1, and FIG. 3 is a signal processing system diagram from a strain gauge. FIG. 4 is an explanatory view for explaining the acting force acting on the gutter by staying in the present embodiment,
FIG. 5 is an explanatory diagram for explaining the acting force acting on the gutter due to the stay and collision of the present embodiment, and FIG. 6 is an explanatory diagram for explaining a change in speed at the time of collision with the gutter of the present invention. 1 ... Gutter, 3 ... Elastic member R1, R2, R3, R4 ... Strain gauge R5, R6, R7, R8 ... Strain gauge for parallel component force

Continuing from the front page (72) Inventor Hiroyuki Tomomatsu 1-1, Sanbonmatsu-cho, Atsuta-ku, Nagoya-shi, Aichi Japan (72) Inventor Shigeo Sunaga 1-1-1, Sanbonmatsu-cho, Atsuta-ku, Nagoya, Aichi Japan Inside Manufacturing Co., Ltd. (72) Inventor Yutetsu Kumaki 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya, Aichi Prefecture Inside Japan Vehicle Manufacturing Co., Ltd. (72) Inventor Masakazu Banno 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya, Aichi Japan (56) References JP-A-60-164220 (JP, A) JP-A-60-122324 (JP, A) JP-A-57-189013 (JP, A) (58) Fields investigated ( Int.Cl. ⁶ , DB name) G01F 1/30 G01G 11/00

Claims (1)

(57) [Claims] When a continuously flowing powder material passes through an inclined gutter, a component force parallel to the gutter and a vertical component force acting on the gutter by the powder material are detected, A method for measuring the flow rate of the granular material based on the detected horizontal component force and the vertical component force.