HU198265B - Continuous sludge evaporating device - Google Patents

Abstract

Apparatus for evaporating and drying slurry based on water or other solvent, especially for preparing a grainy material, comprises a tubular double-walled vessel (1) and two spiral mixing elements (2, 6), an inlet (19) for supplying the slurry into the double-walled vessel (1) and an outlet for delivering dry material, wherein the inlet (19) is connected with a tubular element for supplying the slurry from a container (7) to the double-walled vessel (1), the tubular element including a tubular part (18) made of flexible material, surrounding a mixing shaft (9) reaching the interior of the container (7) and the double- walled vessel (1) is connected by means of its outlet to a unit for comminuting the dry material. <IMAGE>

Description

BACKGROUND OF THE INVENTION The present invention relates to a continuous slurry evaporator for evaporating, drying, comminuting and recovering a solvent or slurry slurry comprising a slurry tank, a mixing shaft passing through the center of the slurry tank, a mixing blade on a mixing shaft, a double , a hammer crusher is mounted at the end of the axis of the "Z" mixers, with a sieve under the hammer crusher and a collecting vessel under the sieve.

In many industrial applications, but mainly white or colored pigments, including fluorescent pigments, used for electrostatic coating of light source coatings have to be made suitable for electrostatic application by surface treatment. As a result of the surface treatment, we obtain easily-sprayable granules with appropriate surface resistance, hydrophobicity, which, during electrostatic application and subsequent heat treatment, form a coating which adheres well to each other and to the source of the light source. The applied coating must be perfectly even. Concentration differences can cause significant differences in the spray material, fillability, adhesion of the coating material, and adhesion to each other, which ultimately results in a coating defect in the finished product.

These factors necessitated the development of a device, apparatus for drying the active ingredient dissolved in an aqueous or solvent medium on the surface of the pigment or powder so that the necessary chemical reactions during the heat treatment were carried out and the solvent recycled. It is also necessary that the dried product obtained as a result of the operation has a particle size such that it can be milled to the desired fineness with an air-jet mill without elutriation.

For this purpose, simple distillation by evaporation is not possible, since the active ingredients are present in the top layer due to the formation of a layer. When added with agitators, high frictional forces occur during solidification, leading to either vessel or agitator rupture. In pore blast drying, the particles also exhibit a concentration gradient and solvent recovery is only possible through expensive cooling-freezing.

The solution to the problem required the development of a continuous pigment powder treatment device. The equipment must be able to handle the slurry in a continuous mode, in a closed apparatus, with constant agitation while the solvent is constantly evaporated. The equipment must continuously charge and grind the material in the solidification phase, dry the material within the required temperature range, and finally ensure continuous extraction of the solid and solvent recovery.

John H. Perry's Manual of Chemical Engineers (Technical Publisher, Budapest, 1968), Volume 1, pages 1035-1043, describes the most important equipment known to date for the continuous treatment of solids and particulates in heat treatment. pages. However, none of the devices described herein are capable of meeting all of the above-mentioned needs that arise during the problem described.

Since no suitable apparatus for solving the above task is available in the literature, it was an object of the invention to provide such an apparatus.

It is an object of the present invention to provide a continuous slurry evaporation device for the evaporation, drying, grinding and solvent recovery of aqueous or solvent slurries. The apparatus consists of a slurry tank, a mixing shaft passing through the center of the slurry tank, a mixing paddle on the mixing shaft, and a tubular double-walled vessel having two "Z" mixers, a hammer crusher at the end of the "Z" mixer shaft. underneath the sieve, and under the sieve, a receptacle. The continuous slurry evaporator according to the invention is characterized in that the agitator shaft passes through a rubber lock which closes or opens the rubber locked control element and is connected to the tubular double-wall vessel via the rubber locking nipple.

In order to facilitate the understanding of the apparatus according to the invention, a drawing appendix is attached to the description, which consists of two figures.

Figure 1 is a vertical sectional view of the apparatus; Figure 2 is a sectional view of Figure 1 in the AA plane.

The material to be treated (pigment, light powder) in the slurry tank 7, while homogenizing the agitator blade 17, is introduced through a rubber seal 18 into a tubular double-walled vessel. There are two opposite-rotatable mixers 2,6, Z, for mixing and conveying the material. At the ends of the shafts 20, the hammer breakers 3 grind the material to a desired particle size of less than 1 mm, which falls through a sieve 4 into the collecting vessel 13. The slurry inflow site is separated from the dryer space by 5 dams, from where mixing and transfer of condensed material 6, 2. mixer.

The section shown in Fig. 1 shows that through the rubber seal 18 attached to the stump 19, the substance to be treated is transferred from the slurry tank 7 to the duplicator section 14. The throughput is controlled by the mechanical or pneumatic actuator 8 while the material flows into the duplicator section 14 along a stirring axis 9. The same figure shows the solvent outlet nozzle 10 which is connected to a cooler not shown in the drawing. The propellant gas is introduced through 11 stumps, while the window 12 is a viewing window for observing the space above the hammer breaker.

The slurry evaporation itself is done as follows: The sectors of the tubular double-walled vessel 1 are heated to a suitable temperature by oil or steam heating while rotating the shafts of mixers 2 and 6, (L "). and then mechanically or pneumatically controlled opening of the rubber seal 18, the slurry is allowed into the duplicator stage 14. Once the solvent has reached its boiling point, the vapors are transported to the coupling coolers along with the carrier and shielding gas introduced through the nozzle 11 where they condense back to the slurry. condensed slurry is lifted by the mixer 6 "Z" to the barrier 5 and dried and rotated in the duplicator zones 15, 16 by means of mixers 2, 2. The dry matter is broken by 3 hammer crushers and passed through 4 sieves into 13 collecting vessels

198,265 granted.

Claims (1)

Patent Claim 5 1. A continuous slurry evaporator for evaporating, drying, comminuting and recovering aqueous or solvent slurry comprising a slurry tank, a mixing shaft passing through the center of the slurry tank, a mixing paddle on the mixing shaft, and a tubular double-walled vessel J , a hammer breaker is mounted at the end of the shaft of the "Z" mixers, a sieve is located below the hammer breaker and a collecting vessel is located under the sieve, characterized in that the mixing shaft (9) is closed or controlled by a control element (8). the rubber seal (18) is connected to the tubular double wall vessel (1).