Hoechst Aktiengesellschaft

Clariant Corporation

Cassella Aktiengesellschaft

Manfred Ziegelmayer

Manfred Sponheimer

Guenther Welt

Reinhard Doenges

Reinhard Donges

Josef Hilbig

Friedrich Engelhardt

Manfred Schrod

Gunther Welt

In the process and the apparatus, a gas stream is divided into three partial gas streams. The first partial gas stream transports the material to be ground into the grinding and friction space of a mill (26), while the second partial gas stream runs around the friction space in the mill. The third partial gas stream is connected to the output side of the mill and takes up the reduced and dried ground material, transported out of the mill by the first and second partial gas streams, in order to transport it to a separator (30).

Process and apparatus for simultaneously grinding and drying a material

Process and apparatus for simultaneously grinding and drying material to

A process and apparatus for screening cellulose ethers which have a finely fibrous or wad-like or woolly structure, wherein the process comprises the following steps:

Process for screening cellulose ethers

The present invention relates to a process and a device for selectively separating the solvents employed in the preparation and purification of products. In this connection the different solvents are removed from the product to be treated by means of mechanical separation and subsequent admission of steam, and are collected separately. As a result of this, mixing of solvents from the preparation and from the purification is avoided, so that the working up of a solvent mixture is superfluous. The proces and the device are preferably used in the process for producing starch ethers and cellulose ethers.

Process for separating solvents used in the purification of products

The present invention relates to a process for careful grinding and simultaneous drying of moist cellulose ether products wherein a moist cellulose ether is introduced by means of a transport gas into a circular space. The moist cellulose ether is impact-comminuted while being circulated in that space, and the product is simultaneously friction-comminuted in a direction opposite to that of the impact comminution. The peripheral speed of the comminution stages, which operate in opposite directions, is regulated to such a value that the resulting grinding energy dries the product to a predetermined residual moisture content. The ground material is conveyed by the gas stream introduced into the comminution space, and the ground material is then separated from the gas stream. If desired, the ground material is subjected to selective screening.

Process for grinding and simultaneous drying of moist cellulose ether

A polymer hydrogel substantially free from monomers and oligomers is prepared by contacting a previously prepared polymer hydrogel with a single-phase mixture of water and a solvent and then separating the mixture of water and solvent from the hydrogel.

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Bischofsheim, Germany

Manfred Ziegelmayer