JPS6335287B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves dispersing water-insoluble resin particles of approximately 4 to 80 μm in solid content in a solids concentration range of 10 to 70% by weight, using water as a medium, and adding a coloring agent and a surfactant as necessary. The present invention relates to a defoaming treatment device for destroying and defoaming bubbles in a slurry paint containing a thickening agent, a thickener, and the like.

Conventionally, slurry paints (hereinafter simply referred to as liquids), which are high viscosity liquids, often contain bubbles during the manufacturing process. Therefore, the particles are adsorbed to the surface of the foam and exhibit defect phenomena such as re-aggregation using the foam as a medium, so defoaming treatment is an essential step from the viewpoint of improving product quality. Conventional defoaming treatments can be broadly classified into the following three methods.

(1) A method of breaking and defoaming by pouring a foam-containing liquid into a vacuum chamber and stirring it.

(2) A method of breaking and defoaming bubbles by generating high-speed vortices in a foam-containing liquid.

(3) A method of breaking and defoaming foam-containing liquids using ultrasonic waves.

However, these conventional methods have various technical problems, and a perfect technology has not yet been established. For example, method (1) has the disadvantage that it takes a considerable amount of time to defoam in the case of high viscosity liquids, making continuous operation difficult. In addition, method (2) had the disadvantage that if solids were present in the foam-containing liquid, precipitation would occur due to centrifugal force. Method (3) had the disadvantage that solids often agglomerated when they were present in the foam-containing liquid.

In view of the above-mentioned conventional technology, the present invention has an extremely rapid defoaming speed, can be operated continuously, and can perform precipitation separation even when resin particles with a particle size of about 4 to 80 μm are present in a foam-containing liquid. The purpose of the present invention is to provide a defoaming treatment device that does not cause air bubbles.

That is, the present invention provides a tank equipped with a pressure reducing means;
A stirring shaft driven by a drive device and installed in the center of the tank; A disc-shaped stirring disk attached to the lower end of the stirring shaft; A stirring disk mounted near the center of the stirring shaft so as to rotate with the stirring shaft. The present invention relates to a defoaming treatment device comprising: a receiving tray; a means for supplying a foam-containing liquid onto the receiving tray from outside the tank; and a liquid outlet installed at the bottom of the tank.

Hereinafter, the present invention will be described in detail with reference to specific examples with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a typical defoaming treatment apparatus according to the present invention in use. The device has a tank 1, to which pressure reducing means, for example a vacuum pump 2, are attached. Furthermore, inside the tank, there is a stirring shaft 3 that is driven by a drive device (not shown) and is installed in the center of the tank, and a stirring disk (disc-shaped) 4 is attached to the lower end of the stirring shaft 3. There is. Furthermore, a saucer 6 is attached to the stirring shaft 3 for receiving the foam-containing liquid supplied from the pipe 5. It is preferable that the size and shape of the saucer 6 be determined so that the saucer 6 rotates together with the stirring shaft 3, and the foam-containing liquid 7 supplied to the saucer 6 is scattered onto the side wall of the tank by rotational centrifugal force and gently flows down along the sidewall. The bubble-containing liquid 7 supplied to the saucer 6 is subjected to strong centrifugal force and inertial force due to the rotation of the saucer 6, causing a spin phenomenon and causing the bubbles to burst. Therefore, the surface of the saucer 6 may be made uneven or grooved. If it is added, it will be easier to break the bubbles.

When using the defoaming device of the present invention, first, the valves 8, 9, and 10 are closed, the valve 11 is opened, and the vacuum pump 2 is operated to reduce the pressure inside the tank 1. The pressure is determined appropriately depending on the viscosity of the foam-containing liquid, but in the case of slurry paint it is -700 to -740 mm.
Hg level is appropriate. The pressure is checked with the pressure reducing gauge 12, and after the pressure has been reduced to a predetermined pressure, the valve 8 is opened while the stirring shaft 3 is rotated, and the foam-containing liquid is poured into the center of the saucer 6. The foam-containing liquid is turned into fine particles by the rotation of the saucer 6, and the bubbles are broken and scattered onto the side wall of the tank. Even after adhering to the side wall, the small amount of air bubbles contained in the tank grow larger due to the vortex generated by the stirring disk 4 at the bottom of the tank.
It is defoamed quickly. The liquid level of the liquid falling at the bottom of the tank 1 rises one after another, and when it reaches the bottom surface of the saucer 6, the valve 8 is closed to stop the supply of the bubble-containing liquid. After continuing to operate for several minutes to break the bubbles floating on the liquid surface on the back side of the saucer 6, the drive was stopped.
The vacuum pump 2 is stopped, the valve 10 is opened, and the inside of the tank 1 is returned to normal pressure. Next, open the valve 9,
The pump 14 is operated through the outlet 13 to take out the defoamed liquid from the system.

Depending on the type of slurry paint, if the bubbles on the liquid surface are difficult to completely break, do not remove all of the liquid from the system, leave some of the liquid, and break the bubbles on the liquid surface during the next operation. You may.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a typical defoaming treatment apparatus of the present invention in use. 1: Tank, 2: Vacuum pump, 3: Stirring shaft,
4: Stirring disk, 5: Foam-containing liquid introduction and supply pipe, 6: Receiver, 7: Foam-containing liquid, 8, 9, 10, 1
1: Valve, 12: Decompression gauge, 13: Defoamed liquid outlet, 14: Pump.

Claims (1)

[Claims] 1 A tank equipped with a pressure reduction means; A stirring shaft driven by a drive device and installed in the center of the tank; A disc-shaped stirring disc attached to the lower end of the stirring shaft; The center of the stirring shaft A defoaming process consisting of a saucer mounted nearby so as to rotate with the stirring shaft; a means for supplying foam-containing slurry paint onto the saucer from outside the tank; and a paint outlet located at the bottom of the tank. Device.