JPH031902A - Automatic control of moisture and viscosity of slip - Google Patents

Abstract

PURPOSE:To always stably keep the properties of slip easy to change by calculat ing the moisture and viscosity of the slip on the basis of the displacement of a float and adding water to a slip tank when moisture is lowered and adding control glaze to the slip tank when viscosity is lowered. CONSTITUTION:A quantitative pump 9 is started to allow the slip in a slip tank 1 to continuously flow in a measuring tank 6 from a slip supply pipe 8 and the floating height of a float 7 after the elapse of a definite time is measured by a sensor 10. Next, the inflow of the slip to the measuring tank 6 is stopped and the float 7 is made stationary to measure the stationary height thereof. The specific gravity and moisture of the slip are known from this measured height and the viscosity of the slip is known from the difference between the floating height and the stationary height. The obtained measured values of moisture and viscosity are inputted to an operational control part 11 and, when moisture is lower than a reference value, water is supplied to the slip tank 1 from a control water tank 12 through a control valve 13 and, when viscosity is lower than a reference value, control glaze is supplied to the slip tank 1 from a control glaze tank 15 through a control valve 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for automatically controlling the moisture content and viscosity of a slurry that is used as a raw material for forming ceramic products.

(Prior Art) It is necessary to keep the moisture and viscosity of slurry, which is the raw material for forming ceramic products, constant during use, and various measuring methods have been devised for this purpose.

Typical methods include the specific gravity method, which measures the specific gravity of sampled slurry and determines the water content from a conversion table, and the method of measuring viscosity by inserting a visco tester into the sampled slurry. However, it is necessary to sample the slurry and then conduct measurements manually, which takes time. And mud 5? The water content and viscosity of slurry tend to change easily due to water evaporation and agitation during use. Therefore, in order to keep the water content and viscosity of slurry constant during use, workers often have to repeat measurements and adjustments. This required a lot of time and effort, and accurate control of moisture and viscosity was considered to be a task that required skill.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems and automatically measures the water content and viscosity of slurry in a short time.
The present invention was completed in order to provide an automatic control method for the moisture content and viscosity of slurry, which can always maintain the moisture content and viscosity of slurry within a certain range based on the measured values without requiring any human intervention.

(Means for Solving the Problems) The present invention, which has been made to solve the above problems, allows slurry in a slurry tank to flow at a constant speed from the bottom of a measuring tank in which a float is provided, thereby causing the float to float. In addition to measuring the height as a dynamic force, the inflow of slurry is stopped and the static height of the float is measured as a static force. Based on these measured values, the water content and viscosity of the slurry are calculated, and these values are calculated. The system is characterized in that water is automatically added into the slurry tank when the water content is lowered by input to the arithmetic control unit, and adjusted glaze is automatically added into the slurry tank when the viscosity is lowered.

The present invention will be explained in more detail below using an example in which the present invention is applied to automatic control of water content and viscosity of slurry for glazing insulators.

(Example) In Fig. 1, (1) is a slurry tank equipped with an agitator (2) inside, (3) is a pump for pumping the slurry, and the slurry in the slurry tank (1) is supplied from a nozzle (4). The structure is such that it is sprayed toward the insulator (5) and glazed.

(6) is a measurement tank provided above the slurry tank (1), the lower half of which is shaped like a cone, and a float (7) is provided inside thereof so as to be movable up and down. This measurement tank (6
) A slurry supply pipe (8) is connected to the center of the bottom.
The structure allows the slurry to be measured to be pumped from the slurry tank (1) by a metering pump (9), and to flow at a constant speed from the bottom of the measuring tank (6) via the slurry supply pipe (8). There is. (9) is an outer tank for collecting the slurry overflowing from the measurement tank (6) and returning it to the slurry tank (1). Further, 0ω is a sensor that detects the height of the float (7).

To measure the water content and viscosity of slurry using such a device, start the metering pump (9) and continuously pump the slurry in the slurry tank (1) from the slurry supply pipe (8) into the measuring tank (6). Inflow into the target market. At this time, the float (7) is pushed upward by the buoyancy of the inflowing slurry and moves upward from position A shown in FIG. 2 in a curve shown by B-C-D. Here, the movement from A to B is due to instantaneous elastic elongation, the movement from B to C is due to elastic aftereffects and exhibits viscoelastic properties, and the movement from C to D is due to viscous flow. Then, the floating height of the float (7) at point D after a certain period of time is measured by the sensor 0ffl. Next, when the flow of the slurry into the measuring tank (6) is stopped, the float (7) lowers in a curve shown as D-E-F-G in FIG.

The movement from D to E is an instantaneous elastic contraction, and from E to F
The movement to is a delayed elastic contraction and exhibits viscoelastic properties. After that, the float (7) comes to rest at point G, so
Measure its static height. This static height is a float (7
), from which the specific gravity and water content of the slurry can be determined. Furthermore, since the difference between points D and G in FIG. 2 indicates the viscoelastic contraction of the slurry, the viscosity of the slurry can be determined from this. Such measurements can be performed automatically at 5-10 minute intervals.

The measured values of moisture and viscosity obtained in this way are manually input to the arithmetic and control unit (01), which compares these measured values with reference values as shown in Fig. 3, and controls the control valve. The control is performed as follows by opening and closing the surface and i1 section valve 06).

First, when the water content drops below the reference value, water is supplied from the regulating water tank 021 into the slurry tank (1) via the regulating valve side. The supplied water is immediately stirred and mixed by the stirrer (2) to raise the water content of the slurry in the slurry tank (1). Generally, the moisture content of the slurry gradually decreases during use, and the moisture content usually does not exceed the standard value, so if the moisture content exceeds the standard value, the water supply can be stopped. .

Next, when the viscosity decreases below the reference value, the adjusted glaze is supplied from the adjusted glaze tank 051' into the slurry tank (1) via the adjustment valve 00. This gradually increases the viscosity of the slurry. On the other hand, if the viscosity increases above the standard value, water can be added, but if you do not want to increase the water content, increase the rotational speed of the stirrer (2) in the slurry tank (1) and stir vigorously. If this is done, the viscosity of the slurry will gradually decrease. In this way, according to the present invention, it is possible to automatically control the water content and viscosity of the slurry in a very short time interval.

Incidentally, FIG. 4 is a graph showing the effect of reducing the viscosity of the slurry by stirring. In other words, this graph shows that the initial viscosity (mariot tube viscosity) is 66 seconds, the moisture content is 41%, and the glaze temperature is 8 seconds.
This figure shows the change in viscosity when slurry adjusted to 'C' is continuously stirred in a tank. As is clear from this graph, stirring greatly reduces the viscosity of the slurry.
It can also be seen that the value decreases even when water is added.

(Effects of the Invention) As explained above, according to the present invention, the moisture and viscosity of the slurry are automatically measured in short cycles by the displacement of the float, and the moisture and viscosity of the slurry are measured according to these measured values. can be maintained within a certain range without requiring human intervention. Therefore, according to the present invention, the easily changeable properties of the slurry can be maintained stably at all times, which is extremely effective in stabilizing and automating the process.

Therefore, the present invention can greatly contribute to the development of industry as a method for automatically controlling the water content and viscosity of slurry by solving the conventional problems.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet explaining the details of the present invention, Fig. 2 is a graph showing the relationship between the flow of slurry and the displacement of the float, Fig. 3 is a block diagram explaining the control details, and Fig. 4 is based on stirring. It is a graph showing viscosity change of slurry. (1): Slurry tank, (6): Measurement tank, (7); Float, θ0: Arithmetic control unit, 021: Adjustment water tank, 051
: Adjustment glaze tank.

Claims (1)

[Claims] The slurry in the slurry tank (1) is made to flow at a constant speed from the bottom of the measurement tank (6) in which a float (7) is installed, and the floating height of the float (7) is measured as a dynamic force. The static height of the float (7) is measured as a static force, the moisture and viscosity of the slurry are calculated based on these measured values, and these values are sent to the calculation control unit (1).
1), water is automatically added into the slurry tank (1) when the water content has decreased, and adjusted glaze is automatically added into the slurry tank (1) when the viscosity has decreased. and automatic control methods for viscosity.