Bayer Aktiengesellschaft

Hans Uhlemann

Ulrich Reinehr

Heiko Herold

Josef Schmoll

Manfred Bucheler

Gerhard Stopp

Reinhard Boeck

Burkhard Braun

Ina Seyffert

Joachim Martin Maasz

Hans Daun

Toni Herbertz

Hermann-Josef Jungverdorben

Alfred Nogaj

Gunter Lorenz

Karlheinz Feltgen

Christian Pieper

Heinz Hausmann

Horst Karkossa

Reinhard Walter

Horts Karkossa

Klaus Nickel

Heinz Heusmann

Reinhardt Walter

Process and apparatus for preparing granulates

In the process for the agglomeration of slightly soluble and hydrolytically sensitive substances, a powder of the slightly soluble substance is conducted, together with at least one water-soluble binder, in free fall through a steam atmosphere at temperatures between 85.degree. C. and 105.degree. C. essentially without the action of compacting forces. In this process, the residence time in the steam atmosphere is approximately 0.5 to 10 seconds. The agglomerates formed are then dried in free fall, so that small solid bridges form from the binder liquid bridges formed at the points of contact between the primary particles. In a following integrated fluidized-bed dryer, the final drying then takes place to a water content of less than 0.5% by weight. The process is carried out in a steam jet agglomerator in which a freely falling product curtain of the pulverulent mixture to be agglomerated is impinged by steam using steam jet nozzles (5, 6). A fluidized-bed dryer (2) is connected at the lower part of the agglomerator (1) in such a manner that the agglomerated particles (4) fall directly into the fluidized bed.

Process and apparatus for the agglomeration of hydrolytically sensitive

A process for the continuous fluidized bed agglomeration of a solid in powder form, wherein the powder, a granulating liquid and propelling air are fed through a three-substance nozzle into the center of a fluidized bed to form a three-phase mixture in the center of the fluidized bed.

Process for continuous fluidized bed agglomeration

Process for the continuous fluidized bed agglomeration wherein the granulating liquid together with propellant air is supplied centrally through a three-phase nozzle on the distributor of the fluidized bed, and at the same time, the solid in powder form is fed into the fluidized bed through the annular space or the three-phase nozzle with the air of a current of propellant air, supplied separately and concentrically.

Apparatus for continuous fluidized bed agglomeration

Granule production is based on particle growth in a fluidized bed (4), in which the liquid starting product is sprayed into the fluidized bed and the finished granular particle is discharged from the fluidized bed (4) with classification. The classification is carried out with the aid of a classifying air flow which is divided into individual single flows (6) to each of which is assigned a zigzag classifier module (7, 17) and a spray nozzle (5) or a group of spray nozzles. The course of the classifying process is such that the granular particles which are too small and have not yet reached the desired diameter are thrown back into the fluidized bed (4) by a return shaft (9, 18) seated on each of the zigzag classifier modules (7, 17) in parallel or radial zones without cross-mixing, in which the relatively small particles impinge at a relatively large distance from the return shaft (9, 18) and the large particles, which have already grown close to the discharge size, impinge at a relatively small distance. The process is carried out with the aid of a fluidized bed granulator, to the inlet plate (2) of which is connected a zigzag classifier, subdivided in a modular manner, in which each zigzag classifier module (7, 17) is provided with a return shaft (9, 18) at the point where it joins the inlet plate (2, 16). In addition, at least one spray nozzle (5) at the inlet plate (2, 16) is allocated to each zigzag classifier module (7, 17).

Process and device for fluidized bed spray granulation

A new process for continuously preparing granules having narrow grain size distribution, comprising

Process for preparing granulates

The zigzag classifier has a classifying space provided with air inlets which is subdivided into zigzag-shaped ducts, which are connected in parallel with respect to the flow, the lengths of which are greater than their widths. In this way a classifier package is formed with a plurality of small duct cross-sections. This design principle permits substantially lower overall heights for the same number of bends.

Zigzag classifier

Polyacrylonitrile filaments having a residual solvent content of less than 5% by weight and a total linear density of over 100,000 dtex can be prepared without contact with an extracting agent for the spinning solvent by a process in which

Preparation of low residual solvent content polyacrylonitrile filaments

Ready-for-despatch filaments and fibres made of acrylonitrile polymers which contain at least 40% by weight of acrylonitrile units can be prepared from a spinning solution in a continuous dry-spinning method in which

Continuous dry-spinning process for acrylonitrile filaments and fibres

The invention relates to a process for continuously removing residual solvent from filaments of dry-spun acrylonitrile polymers to values of below 2% by weight of solvent by a multi-stage hot-wash with low quantities of water.

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Solingen, Germany

Hans Uhlemann