DE1519563A1 - Vacuum thin-film evaporator for highly viscous liquids - Google Patents

Description

Vacuum thin film evaporator for high viscosity. se fluids The invention relates to a vacuum thin film evaporator for highly viscous liquids, in which within an upright evaporator room by means of rotatably arranged, whale wetted by the liquid. large evaporation surfaces are formed.

Vacuum thin-film evaporators are used for thinning or distilling used by liquids. They are of particular importance in polymerization technology, if plastic masses of volatile components, such as residual monomers or solvents, should be freed. With special vacuum thin-film evaporators, the Liquid applied to a large surface by rotating parts Wedge gap is created and so the product is forced constantly by shear forces forms new surfaces.

Egg. The disadvantage of the previously known devices is that they do not evaporate Parts of the viscous liquids can stick to surfaces on which does not clean the equipment by itself.

Devices for vaporizing liquids of the types mentioned here Kind are z. B. in German patents 1 004 590, 1 005 042, 1 o67 002 as well as in the essay "Wedge splitting machine conveyors and evacuation of non-Newtonian Stoffen ", Dr, W.

Rodenacker, in Chemistry-Ing.-Techn. 36 year, 1964, No. 9, pages 898 to 906.

The present invention relates to a vacuum thin film evaporator, with high throughputs with relatively low cost and energy expenditure can be achieved with good evaporation rates. Another object of the invention is a vacuum thin-film evaporator, in which all parts that are to be degassed with the If you come into contact with the product, keep cleaning yourself.

It has been found that one can use a vacuum thin-film evaporator with optimal performance when this is from an upright, downward conically shaped evaporator chamber, in the rotatably arranged, of the Liquid-wetted rollers are arranged parallel to the inner wall.

Wedge gaps are formed here; the rollers are arranged in such a way that that they are both around the soul axis of the conical body and around their own Axis can perform a rotary movement and the rollers at least around the axis of the soul are forcibly driven.

The device according to the invention can be seen from FIGS. 1 and 2. The conical evaporation chamber (Fig. 1) is expediently heated by the executed. Container wall (l) formed. In the evaporation room the rollers (2) are arranged. These rollers get through the drive shaft (8) a rotary movement around the axis of the soul, I and at the same time through the ring gear (6) or the planet gear (6a) a rotation around its own axis II. Up is the The evaporation space is closed off by a coolable or heatable cover (3). The too degassing liquid is in the inlet (4) via a distributor ring (5) into the evaporation chamber given. It then migrates as a result of gravity and the compulsory demand on the inner wall of the container wall (1) and the rollers (2) to the discharge element (7), the is also driven via the shaft (8). At the discharge opening (9) the degassed product withdrawn, while the vapors at the opening (10) from the Evaporator can be withdrawn.

The ring gear (6) can either be at the top, in the middle or at the bottom be attached to the rollers (2). Due to the possibility of different arrangements the greatest friction between the roller and the inner wall of the evaporator can be achieved at a desired level Place. In addition, the friction is caused by the angle of inclination of the cone given.

The double rotation of the rollers (2) once around the axis of the soul I and the rotation around its own axis II will be on the inner wall of the degasser constantly renewing wedge gap is generated. To a compulsory demand of the product To get down, the surface of the degasser or the rollers with can be helical arranged grooves.

A screw conveyor can be used as the discharge element (7).

In this case, the screw is also driven via the shaft (8). The screw then also serves as a vacuum seal.

Another embodiment of the device (Fig. 2) consists in that the rollers (2) are separated from the discharge element (7) by one that is guided from above Drive shaft (11) moved around core axis I via distributor ring (5). The drive the rollers (2) via a drive shaft (11) is advantageous when the discharge element (7) is operated at a different rotational speed than the rollers (2) axis I or if a gear pump is used instead of the worm.

The ring gear (6) can each be arranged in the rollers (2) by a Planet gear (6a) must be replaced when the friction at the upper entry point of the Liquids should be largest.

The device according to the invention is particularly suitable for evaporation of easily decomposable, viscous liquids and for the removal of monomers Components and solvents from polymer melts. A particular advantage is that new, large surfaces are constantly forming, which favors the supply of heat and the degassing effect is increased. Highly viscous, thermally easily degradable substances are gently degassed, since practically none There are areas where degradation as a result of dwell times that cannot be influenced can take place.

Due to the double rotation of the rollers and the resulting Forced conveying, all product components receive the same average residence time.

Claims (1)

Patent claim vacuum thin-film evaporator for highly viscous liquids with inside an upright evaporator chamber which is conical downwards rotatably arranged parallel to the inner wall, wetted by the liquid Rolls that form a wedge gap with the inner wall, with the liquid supplied above and the degassed liquid discharged below by means of a discharge element is, characterized in that the rollers both around the core axis of the conical KSrpers and rotatably mounted around their own axis and at least around the axis of the soul of the cone are positively driven. Sign.