JP3485821B2 - Method for measuring flow characteristics of powders - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring flow characteristics of powder and granules.

[0002]

2. Description of the Related Art For example, in a granular material manufacturing plant,
When the powder or granules are crosslinked or clogged, the plant cannot be operated smoothly. As a physical property of powdery or granular material that affects such crosslinking and clogging phenomenon, flow characteristics are measured to contribute to smooth operation of a plant and the like. Conventionally, as the flow characteristics of the granular material, the repose angle of the granular material and the fluidity corresponding to the easiness of flowing of a certain amount of granular material have been measured.

FIG. 3 shows a conventional method for measuring fluidity. That is, a certain amount, for example, 100 cc, of the granular material 102 measured by the apparent density measuring container 101 is fed to the hopper 10.
Then, the shutter 104 for closing the lower end opening of the hopper 103 was opened, and the time required for discharging a certain amount of the granular material was measured as a value corresponding to the fluidity. The shorter the time required for the discharge, the better the fluidity.

[0004]

However, according to the conventional method of measuring fluidity, when the granular material 102 causes a blocking phenomenon due to friction between the constituent particles, adhesive force, caking, etc., it does not flow out from the hopper 103. In some cases, the liquidity cannot be evaluated because the outflow stopped halfway. This is because the hopper 103 has a shape that is squeezed downward, so that the powder particles below the hopper are consolidated and the blocking phenomenon easily occurs. In order to solve this, the clogging phenomenon can be prevented by enlarging the lower end opening of the hopper 103, but the fluidity cannot be accurately evaluated because the time required for discharging becomes too short. Alternatively, it is possible to release the blockage phenomenon of the granular material by striking the hopper 103, but even if the striking force can be quantified, it is possible to evaluate the fluidity by two factors of the time required for discharging and the striking force. Have difficulty.

Further, a certain amount of powdered or granular materials such as chemicals and detergents is made to flow out from the container when used, or a certain amount is made to flow out from a hopper or the like in order to fill the packaging container. At this time, even if the fluidity (the time required for discharging) as described above is the same, it is difficult to smoothly flow out a predetermined amount from the granular material that can smoothly flow out from the container, the hopper, etc. by a predetermined amount. There are some granular materials. This is the friction between the constituent particles of the powder,
Due to the adhesive force, caking, etc., the outflow may be temporarily stagnant, or it may flow out in a lump in a lump, and the flow behavior may not be uniform. That is, there is a granular material having a non-uniform flow behavior even if the flowability is the same. The uniformity of such flow behavior affects the ease with which a given amount of powder or granules can be metered or filled. Conventionally, it was not possible to quantitatively evaluate the homogeneity of the flow behavior of such a granular material.

It is an object of the present invention to provide a measuring method and a measuring device for the flow characteristics of powdery particles which can solve the above problems.

[0007]

[0008]

Means for Solving the Problems] Features of the present invention method, the powdery grains held by a holding member having an outlet portion, until the set amount of particulate material from the outlet section to fall, the holding member The slope degree is gradually increased, the cumulative fall amount of the granular material and the slope degree of the holding member are measured in time series, and the correspondence relationship between the measured cumulative fall amount and the slope degree has a known flow characteristic. By comparing with the correspondence relationship between the cumulative fall amount obtained for the reference powder and the slope degree, the difference between the slope degree in the former correspondence relation and the slope degree in the latter correspondence relation at the predetermined cumulative fall amount can be calculated. There is a point to seek. When the fluidity of the granular material is good and there is no stagnation in the fall, the cumulative fall amount of the granular material increases as the degree of inclination of the holding member increases.
On the other hand, when the drop is temporarily stopped due to friction between particles constituting the powder, adhesion force, caking, etc., the cumulative fall amount of the powder does not change even if the degree of inclination of the holding member increases.
Therefore, the slope degree at a predetermined cumulative drop amount in the correspondence relationship between the cumulative drop amount and the slope degree obtained for the powder to be measured, and the cumulative drop amount obtained for the reference granular material having known flow characteristics The difference between the slope degree at a predetermined cumulative fall amount in the correspondence relationship between the slope and the slope degree is the difference between the uniformity of the flow behavior of the granular material to be measured and the uniformity of the flow behavior of the reference granular material. Correspond.

It is preferable that the difference in the degree of inclination is obtained for each of a plurality of predetermined different accumulated drop amounts, and the total of the obtained difference in the degree of inclination is obtained. Accordingly, even if the difference in the uniformity of the flow behavior between the measurement target powder and the reference powder is small, the uniformity of the flow behavior can be accurately obtained.

The apparatus for measuring the flow characteristics of the granular material of the present invention is supported by the supporting mechanism of the granular material holding member having the outflow portion and the supporting mechanism so that the granular material falls from the outflow portion. A device for gradually inclining the holding member, a device for measuring the degree of inclination of the holding member in time series, a device for measuring the amount of powder or granular material falling from the outflow portion of the holding member in time series, and known flow characteristics Obtained in advance for standard powders and granules
The correspondence between the accumulated drop amount and the degree of inclination is stored and
Compare the established correspondence relation with the stored correspondence relation, and
And the degree of inclination in the former correspondence relationship
An apparatus for obtaining the difference between the latter correspondence and the degree of inclination . The apparatus of the present invention can be used for carrying out the method of the present invention.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The flow characteristic measuring device 1 for powder and granular material shown in (1) and (2) of FIG. 1 is for measuring the flow characteristic of the powder and granular material 3 held by the holding member 2.
The support mechanism 4, the tilting device 5, the tilt measuring device 6, the weight measuring device 7, and the computing device 8 are provided.

The support mechanism 4 has a rotating member 13 rotatably supported around a horizontal axis by a column 12 provided on a base 11, and the holding member 2 can be attached to and detached from the tip of the rotating member 13. ing. In the present embodiment, the holding member 2 has a shape obtained by dividing a cylindrical body so that the end view has a shape of ¼ circle, and the upper opening is the outflow portion 2 a of the powder or granular material 3.
It is a hollow body.

The tilting device 5 winds the rotation of the motor 16 provided on the base 11 and transmits the rotation to the rotating member 13 via the transmission mechanism 17 and the speed reducing mechanism 18, and the rotating member 13 is rotated. The holding member 2 supported by the support mechanism 4 can be gradually inclined.
Due to the increase in the degree of inclination, the granular material 3 held by the holding member 2 can be dropped from the outflow portion 2a.

The inclination measuring device 6 measures the degree of inclination of the holding member 2 in time series, and in this embodiment, it is constituted by a rotation angle sensor of the rotating member 13.

The weight measuring device 7 measures, in a time series, the cumulative weight of the particles 3 falling from the outflow portion 2a of the holding member 2, and is constituted by a weight sensor in the present embodiment. A saucer 20 for the powder and granules 3 is attached to the.

The computing device 8 is composed of a computer connected to the tilt measuring device 6 and the weight measuring device 7, and is set from the outflow portion 2a based on the measurement results of the tilt measuring device 6 and the weight measuring device 7. It is possible to obtain the degree of inclination when the amount of the granular material 3 falls and output the obtained degree of inclination. Further, the arithmetic unit 8 is based on the measurement result,
The correspondence relationship between the cumulative fall amount of the powder and granular material 3 and the inclination degree is determined in advance by comparing it with the correspondence relationship between the cumulative fall amount and the inclination degree that is previously obtained and stored for the reference powder and granular material having the known flow characteristics. The difference between the slope degree in the former correspondence relationship and the slope degree in the latter correspondence relationship in the integrated drop amount can be calculated, and the calculated slope degree can be output. Furthermore, the arithmetic unit 8
Can obtain the difference in the degree of inclination for each of a plurality of predetermined different accumulated drop amounts, obtain the total of the obtained difference in the degree of inclination, and output the obtained total. An output device 9 such as a printer, a monitor or an external storage device for displaying and storing the output result is connected to the arithmetic device 8.

When the fluidity is measured by the flow characteristic measuring device 1, first, in order to hold the granular material 3 by the holding member 2, a fixed amount of the granular material 3 is put into the holding member 2.
The amount of the granular material 3 to be charged may be appropriately determined according to the volume of the holding member 2, and the accuracy thereof may be appropriately determined according to the required accuracy of flow characteristics. At this time, the outflow portion 2a of the holding member 2 is oriented so that the powder particles 3 can be held by the holding member 2, for example, upward.

Next, the inclination degree of the holding member 2 is gradually increased by the inclining device 5 so that the granular material 3 falls from the outflow portion 2a. In the present embodiment, FIG.
The holding member 2 is inclined so that the outflow portion 2a faces upward as indicated by a solid line in (2) and the outflow portion 2a faces downward as indicated by a chain double-dashed line in FIG. 1 (2). Is gradually increased until all of the fixed amount of the granular material 3 falls from the outflow portion 2a.

The inclination degree of the holding member 2 and the cumulative fall weight of the granular material 3 are time-sequentially measured by the inclination measuring device 6 and the weight measuring device 7, and the measurement result is input to the arithmetic unit 8.
As the inclination of the holding member 2, the inclination measuring device 6 is used.
The tilt angle θ corresponding to the rotation angle of the rotating member 13 measured by is measured in time series. At this time, as shown in FIG. 1 (1), the outflow portion 2a is vertically upward, and the inclination angle θ is set to zero. Thereafter, as shown in FIG. 1 (2), the inclination angle θ is set.
Is gradually increased. Note that, if the tilt angular velocity of the holding member 2 is constant, the tilt angle θ may be obtained by calculating the product of the time from the start of tilt and the tilt angular velocity.
Instead of such an inclination angle θ, for example, the height from the upper surface of the base 11 to the center of the bottom surface of the holding member 2 may be measured as the inclination degree. Granules 3 falling from the outflow portion 2a
As the weight of, the cumulative weight of the powdery or granular material 3 on the tray 20 measured by the weight measuring device 7 is measured in time series.
The integrated weight of the powder or granules 3 may be obtained from the weight of the powder or granules 3 remaining on the holding member 2 measured by, for example, supporting the holding member 2 by the support mechanism 4 via the load cell.

According to the above configuration, it is possible to measure the degree of inclination when the set amount of the granular material falls from the outflow portion 2a. The degree of inclination indicates the fluidity corresponding to the ease of flow of the granular material 3, and the smaller the degree of inclination, the better the fluidity. As a result, even if the powdery or granular material 3 forms a closed state, the fluidity can be evaluated by enlarging the outflow portion 2a so that the outflow portion 2a can be dropped.

In addition, the slope degree at a predetermined cumulative drop amount in the correspondence relationship between the cumulative drop amount and the slope degree obtained for the powdery particles 3 and the cumulative drop amount and the slope degree obtained for the reference powdery particles It is possible to measure the difference between the degree of inclination and the degree of inclination at a predetermined cumulative fall amount in the correspondence relationship. When the fluidity of the granular material 3 is good and there is no stagnation of the fall, the cumulative fall amount of the granular material 3 increases as the inclination of the holding member 2 increases. On the other hand, when the falling is temporarily stopped due to friction between the constituent particles of the granular material 3, adhesive force, caking, etc., the cumulative fall amount of the granular material does not change even if the inclination of the holding member 2 increases.
Therefore, the difference in the degree of inclination corresponds to the difference in the uniformity of the flow behavior with the reference granular material. That is, the uniformity of the flow behavior of the powdery granules 3 is low as the inclination of the powdery granules 3 at the predetermined cumulative drop amount is smaller than the inclination of the reference powdery granules.

Further, it is possible to measure the cumulative total of the differences in the degree of inclination obtained for each of the different cumulative falling amounts. Even if the difference in the uniformity of the flow behavior between the measurement target powder and granular material 3 and the reference powder or granular material is small, the uniformity of the flow behavior can be accurately obtained from the cumulative total. When the inclination degree of the powdery granules 3 at the predetermined cumulative drop amount is smaller than the inclination degree of the reference powdery granules, the larger the total is, the less uniform the flow behavior of the powdery granules 3 to be measured.

FIG. 2 shows the correspondence between the cumulative fall amount of powder and granular material and the degree of inclination measured by the above-mentioned flow characteristic measuring device 1 in which the holding member 2 is made of acrylic. The vertical axis represents the drop rate (%) with respect to the total weight of the dropped total amount, and the horizontal axis represents the inclination angle of the holding member 2 as the degree of inclination. The powder and granules have an average particle diameter of 350 μm, a bulk density of 1100 g / liter, a dense ash having a repose angle of 35 degrees (denoted by ● in the figure), an average particle diameter of 2 to 3 μm, and a bulk density of 200.
g / l, zeolite with a repose angle of 50 degrees (shown by □ in the figure), average particle size 350 μm, bulk density 700 g / l, powder detergent with a repose angle of 38 degrees (shown by Δ in the figure), average particle size 350 μm, bulk A powder detergent having a density of 700 g / liter and an angle of repose of 38 degrees which easily causes caking (indicated by a circle in the figure) was used.

In FIG. 2, when a certain amount, for example, 80% of the total weight of the granular material falls from the outflow portion 2a, the degree of inclination is such that the powder detergent is the smallest, the dense ash is the smallest, and the caking is the second. The powder detergent that is prone to generate is small, and zeolite is the largest. As a result, the powder detergents have the best fluidity corresponding to the fluidity of the four types of powders, the dense ash is the next best, and the powder detergents that are prone to caking are the best, and the zeolite has the most fluidity. Can be evaluated as bad.

Also, for example, dense ash is used as a standard powder and granular material,
When the other three types of powders and granules are measured, the difference between the inclination degree of the measurement target powder and granularity and the inclination degree of the reference powder and granularity at a predetermined cumulative fall amount, for example, a drop rate of 60%. Has the smallest powder detergent, then the smaller powder detergent that is prone to caking, and the largest zeolite,
Moreover, as the difference increases, the degree of inclination of the granular material to be measured becomes smaller than the degree of inclination of the reference granular material. From this, it is possible to evaluate that the powder detergent has the best uniformity of the flow behavior in the three types of powders to be measured, the powder detergent that easily causes caking is the next best, and the zeolite is the worst.

Further, the difference in the degree of inclination is determined by a predetermined plurality of accumulated cumulative amounts of drop, for example, a drop rate of 10%,
20%, 30%, 40%, 50%, 60%, 70%, 8
0%, 90%, 100%, respectively, the sum of the difference of the obtained inclination degree is the powder detergent is the smallest, the powder detergent which is liable to cause caking next is small, the zeolite is the largest, and the cumulative total. The larger the value becomes, the smaller the degree of inclination of the powder or granular material 3 at the predetermined cumulative drop amount becomes than the inclination of the reference powder or granular material. From this, it can be evaluated that the powder detergent has the best uniformity of the flow behavior in the three types of powder particles to be measured, the powder detergent having the second highest tendency to cause caking, and the worst zeolite.

The present invention is not limited to the above-described embodiment, and for example, a container-shaped member is used as the holding member 2, or the powder or granular material is placed and held and tilted so that the powder or granular material is removed from a part of the peripheral edge. It may be a plate to be dropped, and when a plate is used, a part of the peripheral edge of the plate becomes the outflow portion. Alternatively, the volume of the powder or granules may be measured instead of the weight.

[0028]

EFFECTS OF THE INVENTION According to the present invention, the fluidity can be quantitatively and accurately evaluated even in the case of a granular material that easily forms a closed state.
It is possible to provide a measuring method and a device for powder and granular material, which can quantitatively evaluate the uniformity of flow behavior.

[Brief description of drawings]

FIG. 1 is a flow characteristic measuring device according to an embodiment of the present invention (1)
Is a front view, (2) is a partial side view

FIG. 2 is a diagram showing a relationship between an inclination angle and a falling rate of the powder or granular material according to the embodiment of the present invention.

FIG. 3 is an explanatory view of a conventional flow characteristic measuring device.

[Explanation of symbols]

1 Flow characteristic measuring device 2 holding member 2a Outflow part 3 powder 4 Support mechanism 5 Tilt device 6 Tilt measuring device 7 Weight measuring device 8 arithmetic unit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-116449 (JP, A) JP-A 2000-74811 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 11/00

Claims (3)

(57) [Claims] 1. A powdery material is held by a holding member having an outflow portion.
Hold it until the set amount of powder or granules falls from the outflow part.
The inclination of the holding member is gradually increased, and the accumulated fall amount of the powder and granular material and the inclination of the holding member are changed with time.
Measured in the column, the correspondence between the order of tilting the accumulated drop amount was the measured, already
Accumulated drop determined for reference powders with known flow characteristics
Predetermined by comparing with the correspondence between quantity and degree of inclination
And the degree of inclination in the former correspondence with the accumulated fall
A method for measuring the flow characteristics of granular materials to determine the difference between the degree of inclination and the degree of correspondence between users . 2. The difference in the degree of inclination is different by a predetermined value.
Calculated for each of the multiple accumulated fall amounts, and the calculated tilt
The method for measuring the flow characteristics of a granular material according to claim 1, wherein the cumulative total of the differences in the degree of inclination is obtained. 3. A support mechanism for a powder / granular material holding member having an outflow portion.
And its support mechanism so that the granular material falls from the outflow part.
A device for gradually inclining the holding member supported by the device, a device for measuring the degree of inclination of the holding member in time series, and the amount of powder or granules falling from the outflow portion of the holding member in time series.
Product determined in advance for a measuring device and a reference granule with known flow properties
The correspondence between the calculated drop amount and the degree of inclination is stored and measured.
The correspondence relationship that was stored and the correspondence relationship that was stored are compared, and
The degree of slope in the former correspondence and the latter in the cumulative fall amount
And a device for obtaining a difference from the degree of inclination in the correspondence relationship of
An apparatus for measuring the flow characteristics of powder particles.