JP2672696B2 - Capillary radius and contact angle measuring device for powder layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a sample granular material layer filling pipe having a bottom through which liquid can flow in order to measure the capillary radius and contact angle of the granular material layer. And a drive device for vertically approaching a container containing a liquid to be permeated from the bottom into the sample powder layer in the pipe, and contacting the sample powder layer in the pipe with the liquid in the container After that, a controller for automatically operating the drive device is provided so as to stop the approach of the pipe and the container, and the weight change of the pipe due to the liquid permeation into the sample granular material layer in the pipe is measured. And a relative position between the pipe and the container when the sample powder / particle layer in the pipe is brought into contact with the liquid in the container is a set relative position in which the sample powder / particle layer and the liquid are in contact with each other. A position determination means for determining whether or not Based on the stop instruction from the position determining means relates to a device and output means for stopping the drive device and the relative position of the pipe and the container reaches the set relative position.

[Conventional technology]

Conventionally, this type of device operates a timer with a measurement start operation, and brings a pipe and a container close to each other for a time set by the timer, so that a sample granular material layer in the pipe becomes a liquid in the container, It was configured to be in contact with the bottom through which liquid can freely pass.

However, this device causes a large variation in the depth at which the sample granular material layer in the pipe penetrates into the liquid in the container, and in the end, it is difficult to realize a highly accurate measurement with a large measurement error.

Further, as an improvement and development of this device, a position determination means for determining the relative position of the pipe and the container is provided, and an output means for stopping the drive device when the container of the pipe reaches the set relative position is provided. A device was invented (Japanese Patent Application No. 2-101421).

[Problems to be solved by the invention]

However, although such a device showed an improvement in the accuracy of the measuring device, the capillary radius and contact angle of the granular layer to be sought were separately determined and displayed, so it is necessary to quickly obtain the necessary measurement results. I couldn't. This was not efficient, and it was not possible to quickly obtain the required physical properties of the granular material layer.

An object of the present invention is to provide a device capable of measuring a capillary radius and a contact angle at the same time within a short time and without sacrificing accuracy, which is also called a basic evaluation means relating to the affinity between a granular material layer and a liquid. To do.

[Means for solving the problem]

The characteristic configuration of the present invention is, in the contact angle measuring device for the capillary radius of the powder / granular material layer specified in the section of [Industrial application], in the case where there is an increase in weight by the measuring device, measurement by the measuring device. A means for storing the time change of the weight, a means for calculating the parameter a in the following equation from the stored time change of the weight by the least square method, and W _t ² = a · t + b, and then a parameter A in the following equation Means for calculating by the square method, W _t = t / (A · t + B) means for determining whether or not the measurement results of the a and A are substantially unchanged, and the measurement results of the a and A are substantially And a means for calculating the capillary radius r and the contact angle θ of the powder / particle layer from the a and A calculated by the a calculating means and the A calculating means according to the following equation, (However, ρ _L is the liquid density, g is the acceleration of gravity, ε is the porosity of the powder layer, γ _L is the surface tension of the liquid, η _L is the liquid viscosity, and S is the cross-sectional area of the powder layer.) A means for displaying the capillary radius r and the contact angle θ of the powder / granular material layer calculated by the capillary radius r and the contact angle θ calculation means is provided, and the operation and effect thereof are as follows.

(Operation)

Unlike the conventional device, the capillary radius r and the contact angle θ of the granular layer are calculated separately and are not individually displayed.
Since the capillary radius r and the contact angle θ of the granular layer can be obtained at the same time with one measurement, and the permeation weight in the saturated state can be easily predicted from the approximate expression even if the permeate does not reach the equilibrium condition. , The measurement time will be greatly shortened.

Further, since the least squares method is used for the calculation of the parameters, the variation in the measurement data is absorbed, and the capillary radius r and the contact angle θ of the granular layer can be measured with high accuracy.

〔The invention's effect〕

As a result, it is possible to provide a device capable of measuring the capillary radius and the contact angle at the same time within a short time, and also as a basic evaluation means relating to the affinity between the granular material layer and the liquid, and without lowering the accuracy. became.

As described in claim 2, the intermittent movement execution means and the intermittent movement instruction means cause the pipe and the container to approach each other intermittently, and the weight measured by the measuring instrument is read by the measured value storage means when the drive device is stopped. Then, the measurement error due to the dynamic inertia of the pipe or the container is eliminated, and a plurality of measured weights are read and stored by the measured value storage means, and the deviation determination means that the deviation of the plurality of measured weights is within the set range. Until it is confirmed, the measured weight is read and stored by the measured value storage means, and when the deviation is within the set range, the stored value determination means determines the measured weight to be stored based on the stable measured weight, and the determined value. By eliminating the error in the determined measured weight stored in the storage means due to the shaking of the pipe and the liquid, the immersion depth of the sample granular material layer in the liquid can be made more strictly constant,
Therefore, the accuracy of simultaneous measurement of the radius of the capillary and the contact angle of the powder / granular layer can be improved more effectively.

〔Example〕

Next, an example of a device for measuring a capillary radius of a granular material layer and a contact angle according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, a pipe (1) having a liquid-permeable bottom such as a filter paper bottom is hung on a measuring device (2) such as an electronic balance to elevate a driving device (3) such as a linear head motor. ), The container (5) is placed on the table (4), and the container (5) is moved up by the driving device (3) to approach the pipe (1), and the sample granular material filled in the pipe (1) The liquid (L) in the container (5) is permeated into the layer (P) from the bottom of the pipe (1), and the weight change of the pipe (1) due to the permeation of the liquid (L) into the sample granular material layer (P) is caused. It is configured to measure with a scale (2).

Further, a computer (C) for automatically executing the operation of the driving device (3) and the processing of the information from the weighing instrument (2) is provided, and the input device (6) for the computer (C), and
A display device (7) for displaying the measurement result obtained by the computer (C) is provided.

The computer (C) is composed of a controller (A) for automatically operating the drive unit (3) and an arithmetic unit (B) for calculating various data based on a change in measured weight of the weighing machine (2). .

As shown in FIG. 2, the controller (A) has the following (a)
The means of the items (h) to (h) are provided.

a) Immersion of the pipe (1) into the liquid (L), that is, a container, in the intermittent movement execution means (8) that intermittently operates the drive device (3) based on the measurement start instruction from the input device (6) Pipe dipping instruction means (9) for instructing the ascent of (5).

The intermittent movement executing means (8) actuates the driving device (3) for a very short time of, for example, 0.2 seconds per time.

b) Measured value storage means (11) for reading and storing a plurality of weights measured by the weighing machine (2) when the drive device (3) is stopped based on the information from the intermittent movement execution means (8).

c) Deviation determining means (12) for determining whether or not the deviations of the plurality of measured weights are within a set range based on the information from the measurement storage means (11).

That is, for example, it is programmed to determine whether all of the latest read measured weights of three or more set numbers have deviations in the set range from the average value.

d) Stored value determination means (13) for determining the measured weight to be stored based on the information from the measured value storage means (11) when the deviation is within the set range based on the information from the deviation determination means (12). .

For example, the above average value, the measured weight closest to the average value,
A suitable value, such as the latest measured weight, is programmed to determine the measured weight to be stored.

e) A determined value storage means (14) for storing the determined measured weight from the stored value determination means (13).

f) When the deviation falls within the set range based on the information from the deviation determination means (12), the intermittent movement execution means (8) instructs the next intermittent movement, that is, the intermittent movement instruction means (8) for raising the container (5). 15).

g) Based on the information from the determined value storage means (14),
Memorized value change state judging means (16) for judging whether or not the determined measured weight has increased.

h) Stop position determining means (1) for transmitting a stop instruction of the driving device (3) to the output means (17) when the determined measured weight increases based on the information from the stored value change state determining means (16).
8).

That is, if the measured weight has not increased, the drive device (3) does not stop, the intermittent movement by the intermittent movement execution means (8) is continued, and the previous operation is repeated.

As shown in FIG. 3, the computing unit (B) has the following (a)
The means of items (h) to (h) are provided.

(A) S calculation means (19) for calculating the cross-sectional area S of the sample granular material layer based on ρs, Ws, H from the input device (6) by the following formula S = W _S / (ρ _S · H) .

In addition, ρ _s is the true density of the sample granular material layer (P) filled in the pipe (1), W _s is the weight of the sample granular material layer (P), and H is the sample granular material layer (P). Is the filling height of.

(B) Based on ρs, Ws, and H from the input device (6), calculate the porosity ε of the sample granular material layer by the following formula. Ε calculating means (20) for calculating by.

(C) The measurement timer (2) which starts when the drive (3) is stopped by the information from the output means (17)
1).

W _t -t correlation storing means for storing the measurement correlation time t from (d) measuring instrument and measuring the weight Wt from (2) measuring timer (21) (22).

(E) W _t on the basis of information from -t correlation storing means (22), meter data of measurement time t from the measured weight Wt and the measurement starting from (2), the least squares method approximated by the following equation Means (23) for calculating the parameter a by.

W _t ² = a · t + b Note that the parameter b represents the intercept, but since it is not related to the calculation of the capillary radius and the contact angle, only a is obtained here.

(F) Then, W _t based on information from -t correlation storing means (22), when the lapse of set measurement time, minimize the data of measurement time t from the measured weight W _t and the measurement start approximated by the following equation Means (24) for calculating the parameter A by the square method.

W _t = t / (A · t + B) (G) A means (25) for determining whether or not the measurement results of a and A converge with sufficient accuracy above a certain level and are substantially unchanged.

That is, whether or not the i-th measured value a _i , A _i of a, A is approximately equal to the i-1 -th measured value a _i-1 , A _i-1 of a, A respectively, or whether the measured value a _{i It} is determined whether or not the difference between _i , A _i and the measured values a _i-1 , A _i-1 has converged to be less than or equal to the set value.

( _H ) ρ _L , η _L , g, γ _L from the input device (6), S from the S calculating means (19), ε from the ε calculating means (20), and a from the a calculating means (23). , A based on A from the calculating means (24), the average capillary radius r of the sample granular material layer and the contact angle θ between the sample granular material layer (P) and the liquid (L) are calculated as follows. The following equation obtained based on the general solution of the Washburn equation regarding the increase of liquid permeation into the R, θ calculating means (26) for calculating by.

Note that ρ _L is the density of the liquid (L) in the container (5), η _L is the viscosity of the liquid (L), and g is the acceleration of gravity. γ _L is the surface tension of the liquid (L), which is determined in advance by a surface tension measuring method such as a ring method.

Next, the measurement by the above device will be described with reference to FIG.

1) When ρ _S , W _S , H, ρ _L , η, γ _L , g is input by the input device (6), S and ε are calculated by the means (19), (20).

2) When the start of measurement is instructed by the input device (6), the container (5) is intermittently raised. Then, each time the container (5) is stopped, it is judged whether the surface tension or the buoyancy can be detected.

3) If the surface tension or buoyancy cannot be detected, the intermittent rise of the container (5) is continued.

4) If surface tension or buoyancy can be detected,
The intermittent rise of the container (5) is stopped, the measurement timer (21) is started, and the time reading is started.

5) If the correlation between W _t and t by means (22) has elapsed is stored measurement time, the measurement value of W _t and ^{_{t W t 2 = a · t}} + b
And is calculated by the method of least squares.

6) Then, after a lapse of further measurement time, by approximating the measured values of the Wt and t in _{W t = t / (A ·} t + B), to calculate the A by the least squares method.

7) Substitute the measured values of W _t and t into the above approximation formula to determine whether or not a and A fluctuate (whether or not a and A converge with sufficient accuracy). If
The container (5) is again raised intermittently and the measurement is repeated.

8) When the fluctuations of a, A are small, this a, A and ρ _L ,
cos θ based on η _L , γ _L , g, ε, S or cos as required
θ to θ are calculated together with r by means (26).

9) r, cos θ or θ if necessary, and ρ _S , W _S , H, ρ _L , η, γ _L , g, W, ε, r as required by the display (7). Shown.

(Another embodiment)

 Next, another embodiment will be described.

When the sample granular material layer (P) in the pipe (1) is brought into contact with the liquid (L) in the container (5), the pipe (1) may be lowered by the driving device (3), or the pipe (1) may be lowered. The relative position of (1) and the container (5) is the sample powder layer (P).
Various position determination means can be used to determine whether or not the set relative position in which the liquid (L) and the liquid (L) come into contact with each other. For example, a non-catalytic sensor such as an optical sensor is used to detect the relative positional relationship between the pipe (1) and the container (5), and information from the sensor is used to stop the driving device (3) by the output means (17). You may comprise.

A measurement timer is not always necessary, but it is convenient to use it because it can quantify the measurement time.

The data displayed by the display (7) may be at least r, cos θ or θ.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is a conceptual diagram of the apparatus, FIG. 2 is a block diagram of a controller, FIG. 3 is a block diagram of an arithmetic unit, and FIG. 4 is an operation. It is a flow chart of explanation. (1) ... pipe, (2) ... measuring instrument, (3) ... driving device, (5) ... container, (7) ... display means (display), (8) ... intermittent movement execution Means, (11) ... measured value storage means, (12) ... deviation determination means, (13) ... memorized value determination means, (14) ... determined value storage means, (15) ... intermittent movement instruction means , (16) ... Memorized value change state determination means,
(17) …… Output means, (18) …… Stop position determination means,
(22) …… Means for storing the time change of the measured weight, (23)
...... Parameter a calculation means, (24) ...... Parameter A calculation means, (25) ...... Parameter a, A change determination means, (2
6) ... Capillary radius r, contact angle θ calculation means, (A) ... controller, (L) ... liquid, (P) ... sample powder layer.

Claims (2)

(57) [Claims] 1. A pipe (1) for filling a sample powder or granular material layer having a freely permeable bottom portion, and a liquid (L) for permeating the sample powder or granular material layer (P) in the pipe (1) from the bottom portion. A drive device (3) for bringing the container (5) for accommodating the liquid into close proximity in the vertical direction is provided, and the sample granular material layer (P) in the pipe (1) is brought into contact with the liquid (L) in the container (5). After that, a controller (A) for automatically operating the drive device (3) is provided so as to stop the approach of the pipe (1) and the container (5), and the sample granular material layer in the pipe (1) is provided. A measuring instrument (2) for measuring the weight change of the pipe (1) due to the permeation of the liquid (L) into the (P), and a sample granular material layer (P) in the pipe (1) are provided in the container (5). ), The relative position of the pipe (1) and the container (5) is set so that the sample granular material layer (P) and the liquid (L) are in contact with each other. ) Is provided with position determining means for determining whether or not the relative position of the pipe (1) and the container (5) is set to the set relative position based on a stop instruction from the position determining means. In this case, the device is a device for measuring the radius of a capillary and the contact angle of a granular material layer, which is provided with an output means (17) for stopping the drive device (3), wherein the weighing is performed by the weighing device (2). Means (22) for storing the time (t) change of the measured weight (Wt) by the instrument (2), and means (23) for calculating the parameter a in the following equation from the stored time change of the weight by the least square method. And W _t ² = a · t + b, and means (24) for calculating the parameter A in the following equation by the least squares method, and W _t = t / (A · t + B). A means to determine whether it has stopped changing (25) a, when the measurement results of A is no longer substantially change,
Calculated by the a calculating means (23) and the A calculating means (24)
A means (26) for calculating the capillary radius r and the contact angle θ of the granular layer from a and A according to the following equations, (However, ρ _L is the liquid density, g is the acceleration of gravity, ε is the porosity of the powder layer, γ _L is the surface tension of the liquid, η _L is the liquid viscosity, and S is the cross-sectional area of the powder layer.) Means (7) for displaying the capillary radius r and the contact angle θ of the powder / granular material layer calculated by the capillary radius r, the contact angle θ calculation means (26); Device for measuring capillary radius and contact angle of body layer. 2. An intermittent movement executing means (8) for intermittently actuating the drive device (3) is provided, and in forming the position determining means, means (a) to (g) below, that is, B) Measured value storage means (11) for reading and storing a plurality of weights measured by the weighing machine (2) when the drive device (3) is stopped based on the information from the intermittent movement execution means (8), (B) Deviation determination means (12) for determining whether or not the deviations of the plurality of measured weights are within a set range based on the information from the measured value storage means (11), (c) the deviation determination means ( When the deviation falls within the set range based on the information from 12), the stored value determination means (13) for determining the measured weight to be stored based on the information from the measured value storage means (11), (d) Determined value storage means for storing the determined measuring means from the stored value determining means (13) (14), when the deviation is within the set range on the basis of the information from the (e) said offset determining means (12), the intermittently moving execution means (8)
(F) intermittent movement instruction means for instructing the next intermittent movement, and (f) a storage value change state for determining whether the determined measured weight has increased based on information from the determined value storage means (14). Determining means (16), (g) when the determined measured weight increases based on the information from the stored value change state determining means (16), the output means (1
7. The device for measuring the capillary radius and the contact angle of the powder / particle layer according to claim 1, further comprising stop position determining means (18) for transmitting a stop instruction to 7).