JPH0310059B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe for filling a sample powder or granule having a bottom portion through which liquid can freely flow, a container for storing a liquid to be permeated into the sample powder or granule in the pipe from the bottom, and a sample powder or granule. It is equipped with a measuring device that measures the weight change of the pipe due to liquid penetration into the pipe, and based on the information from the measuring device, the contact angle between the sample powder and the liquid in the container, that is, as shown in Fig. 6, is determined. , surface tension γ _L of liquid L,
This invention relates to an improvement of an apparatus for determining the angle θ determined by the surface tension γ _S of a fixed S and the interfacial tension γ _SL of a solid-liquid interface.

Conventional devices were configured to automatically record changes in the weight of the pipe due to liquid permeation into the sample powder on a graph showing the correlation between the measured weight and measurement time. In order to find the contact angle between
This method has disadvantages such as requiring separate manual processing, decreasing measurement accuracy due to errors in reading required values, and requiring a lot of time and effort for calculations.

An object of the present invention is to automatically calculate and display the contact angle between a powder and a liquid, so that highly accurate measurement can be performed reliably and quickly.

A characteristic configuration of the contact angle measuring device according to the present invention is that it stores temporal changes in weight Wt measured by a measuring instrument for measuring changes in weight of a pipe due to liquid penetration into a sample powder filled in the pipe. Means, from its stored weight change 1/Wt on the x-axis and
A means for calculating the slope KW _∞ and the y-axis intercept K of the following equation y=KW _∞ x-K −(1) in the coordinates with dWt/dt as the y-axis, the calculated K, and the setting or The following value ε calculated from the setting value of the input means: Void ratio S in the sample powder packed bed in the pipe: Cross-sectional area ρ _L of the sample powder packed bed in the pipe Density η of the liquid in the container for infiltrating the granules: Viscosity g of the liquid: Based on the gravitational acceleration, the average capillary radius r in the sample powder packed bed in the pipe is calculated by the following formula: r = (8ηK/ εSρ _L ² g) ^1/2 − (2), the calculated r, the set or calculated ε, S and g, the calculated
Based on W _∞ calculated from KW _∞ and K, and the surface tension γ _L of the liquid in the container set by the input means or actually measured by the measuring device, the sample powder in the pipe and the liquid in the container are determined. We have provided a means to calculate the contact _angle θ _between the That's right.

In other words, the permeation speed U of liquid into the powder-filled layer in the pipe is theoretically expressed by the following equation (a).

U=dWt/dt=K(W _∞ /Wt−1) =KW _∞・1/Wt−K −(a) However, W _∞ is the permeating liquid at the time when liquid permeation into the sample powder reaches equilibrium. weight,
Moreover, K=r ² εSρ _L ² g/8η −(b).

Therefore, the temporal change in the measured weight Wt is stored, and as shown in Fig. 3, 1/Wt and dWt/dt at time t are calculated from the stored weight change, and the calculated values are calculated. , 1/Wt on the x-axis and dWt/dt on the y-axis, as is clear from the above equation (a) and the above equation (1), a straight line as shown in Figure 4 is drawn. is obtained. Then, the slope α of the straight line is KW _∞ , the y-axis intercept B is K, and W _∞ and K are found from α and β.

On the other hand, if the above equation (b) is converted, the above equation (2) is obtained, and if K is found as described above, from equation (2) and the input ε, S, ρ _L , η, g Based on, r can be calculated.

If W _∞ and r can be calculated as described above, then from the above formula (3) and the input ε,
The contact angle θ can be calculated based on S, γ _L and g, and the above information processing and arithmetic processing are processed by a microcomputer, and the determined contact angle θ is numerically displayed on a display device. It is.

As a result, the contact angle θ can be determined extremely accurately and extremely quickly without any analytical errors or calculation errors when determining W _∞ and K. , drugs,
It is now possible to provide measuring devices that have great practical value in a wide range of fields such as cosmetics and food.

Next, examples will be shown.

As shown in FIG.
The container 5 is placed on a stand 4 attached to a lifting actuator 3 such as a linear head motor, and then the container 5 is placed on the sample powder S filled in the pipe 1.
The container 5 is raised by an actuator 3 to infiltrate the liquid L in the pipe 1 from the bottom of the pipe 1, and the change in weight of the pipe 1 as the liquid L permeates into the sample powder S is measured by a measuring device 2. It has been done.

Based on the measured value from the measuring instrument 2 and the set value from the input means (6) such as a keyboard, the device 7 for displaying the measurement results such as an X-Y plotter is operated, and the actuator 3 is started and stopped. A microcomputer 9 is provided for giving operation commands to the operation section 8 based on information from the input means (6) and for receiving a measurement start command from the operation section 8. Note that the speed regulator 10 is connected to the actuator 3
This is to artificially set the rising speed of the saucer 5.

The operation steps of the above-mentioned measuring device will be explained below with reference to the flowchart of FIG.

(1) Input the following various setting values from the input means (6).

ρ _S : True density of the sample powder S filled in the pipe 1 W _S : Weight of the sample powder S H: Filling height of the sample powder S T: Measurement time ρ _L : Inside the container 5 Density of the liquid L η: Viscosity of the liquid L γ _L : Surface tension of the liquid L g: Gravitational acceleration (2) Based on the set values ρ _S , W _S , H, the cross-sectional area S of the sample powder layer Then, the porosity ε is calculated using the following formulas (a) and (b).

S=W _S /ρ _S H −(a) ε=SH−(W _S /ρ _S )/SH −(b) (3) The actuator 3 raises the container 5 in response to the measurement start command from the input means (6). When the liquid L comes into contact with the pipe 1, the actuator 3 is stopped and a measurement timer is started.

(4) The weight W _t measured by measuring instrument 2 is input, and W _t
At the same time as the start of increase, measurement time t is input from the measurement timer.

(5) Store the correlation between W _t and t in memory.

(6) When the measurement time T has elapsed, the memorized W _t and t
Based on the correlation, a permeation rate curve as shown in FIG. 3 is displayed on the display device 7.

(7) Based on the penetration rate curve, as shown in Figure 4.
A relationship diagram between dWt/dt and 1/Wt is drawn on the display device 7.

(8) Based on the slope α of dWt/dt and 1/Wt and the y-axis intercept B, the penetrating liquid weight W _∞ at the time when the liquid L reaches equilibrium with respect to the sample powder S, and
The constant K is calculated using the following formulas (c) and (d).

W _∞ = α / K − (c) K = B − (d) (9) Based on the set values ρ _L , η, g and the calculated values ε, S, K, the average capillary radius r of the sample powder layer of,
Calculated using the following formula (e).

r=(8ηK/εSρ _L ² g) ^1/2 −(E) (10) Based on the set values γ _L , g and the calculated values ε, S, W _∞ , r, calculate the difference between the sample powder S and the liquid L. The contact angle θ between and the adhesion tension γ _L cos θ are calculated using the following formula (f).

γ _L cosθ=rgW _∞ /2εS −(f) (11) Set value ρ _S , W _S , H, T, ρ _L , η, γ _L , g and calculated value W _∞ , ε, r, γ _L cosθ, θ is recorded and displayed on the display device 7.

(12) The actuator 3 lowers the container 5 to the lower limit setting position to complete the measurement.

Next, another example will be shown.

The porosity ε and the cross-sectional area S of the sample powder packed bed may be manually set in the input means (6).

In addition, the surface tension γ _L of the liquid L may be actually measured using a measuring device using the ring method, and the measured value may be automatically set in the input means (6), or a platinum ring may be used instead of the pipe 1. It is suspended from the measuring device 2 and is configured to actually measure the surface tension γ _L of the liquid L in advance using the ring method, and to store the measured value in the microcomputer 9 and input it when measuring the contact angle θ. It's okay. The ring method will be explained below with reference to FIG. 7, using the measuring instrument 2 as an example. An attachment configured to allow the platinum ring 11 to be suspended by the rigging 12 in a substantially horizontal position is suspended from the hook 2a of the measuring instrument 2, and the platinum ring 11 is brought into contact with the liquid L by raising the container 5, and then, The container 5 is lowered, the maximum load P is measured by the measuring device 2, and the microcomputer 9 calculates the surface tension γ _L using the following formula.

γ _L =FP/4πR where F is a correction coefficient, π is pi, and R is the radius of the platinum ring 11.

It is sufficient that the display device 7 displays at least the contact angle θ, and therefore the microcomputer 9
It suffices if it has at least the functions shown in FIG.

The container 5 may be raised and lowered artificially, and the timing for the start of measurement and the start of calculation of the contact angle θ by the microcomputer 9 may be determined based on the state of change in the weight Wt measured by the measuring instrument 2.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. FIG. 2 is a flowchart showing the operating state in the embodiment of the present invention. Figure 3 shows Wt-t
FIG. 4 is a dWt/dt-1/Wt diagram. FIG. 5 is a diagram showing how microcomputers respond to complaints. FIG. 6 is an explanatory diagram of the contact angle θ. FIG. 7 is an explanatory diagram of the circular ring method. 1... Pipe, 2... Measuring instrument, 5... Container, S
...Sample powder, L...Liquid.

Claims (1)

[Scope of Claims] 1. A pipe 1 for filling a sample powder or granule material having a bottom portion through which liquid can freely flow, a container 5 for storing a liquid L to be permeated into the sample powder material S in the pipe 1 from the bottom, and a sample powder material. A device comprising a measuring device 2 for measuring a change in the weight of the pipe 1 as the liquid L permeates into the body S, a means for storing a temporal change in the weight Wt measured by the measuring device 2; Means for calculating slope KW _{∞ and y-axis intercept K of the following equation y=KW ∞ x} -K −(1) in coordinates with 1/Wt on the x-axis and dWt/dt on the y-axis from weight change, and its calculation and the following value ε set in the input means (6) or calculated from the set value of the input means: void ratio S in the packed bed of the sample powder S in the pipe 1: the above sample powder Cross-sectional area of the packed layer of the granular material S ρ _L : Density of the liquid L in the container 5 η : Viscosity of the liquid L g : Average capillarity in the packed bed of the sample granular material S in the pipe 1 based on gravitational acceleration Means for calculating the radius r by the following formula r = (8ηK/εSΡ _L ² g) ^1/2 - (2), the calculated r, the set or calculated ε, S and g, the calculated
Based on W _∞ calculated from KW _∞ and K, and the surface tension γ _L of the liquid L in the container 5 set by the input means 6 or actually measured by the measuring device, the sample powder S in the pipe 1 and The powder is provided with means for calculating the contact angle θ with the liquid L in the container 5 using the following formula cosθ=rgW _∞ /2εSγ _L −(3), and is provided with a device 7 for displaying the calculated θ. Contact angle measuring device between particles and liquid.