Evonik Degussa Gmbh

Degussa - Huls Ag

Dmc2 Degussa Metals Catalysts Cerdec Ag

Omg Ag & Co Kg

Josef Piroth

Ralph Kiessling

Rainer Domesle

Martin Foerster

Heike Riedemann

Michael Harris

Dieter Detterbeck

Ann Gray

Thomas P Riedemann

Holger Pitsch

Ulrich Schlachter

Willi Krampe

Frank Dieter Huenig

Thomas Riedemann

Dry liquids having a particle size distribution (cumulative undersize) are prepared by passing the liquids and a hydrophobic, pyrogenically prepared silica through a clearly defined, spatially limited shear zone in which the liquids are broken up into small droplets and are surrounded by the hydrophobic, pyrogenically prepared silica.

Dry liquids, and processes for their preparation

The invention provides a process for coating a cylindrical carrier structure with a predetermined amount (target take-up) of a coating suspension, wherein the carrier structure has a cylinder axis, two end faces, an encasing face and an axial length L and a large number of channels running from the first end face to the second end face. The process comprises: a) vertically aligning the cylinder axis of the carrier structure and filling the empty volume of the channels up to a predetermined height H starting from the lower end face, b) removing the excess coating suspension through the lower end face of the carrier structure down to the target take-up, c) turning the carrier structure 180&deg;, so that the upper and lower end faces are exchanged one for the other, and d) repeating steps a) and b), wherein the height H , up to which the channels are filled in this case is given by H &equals;L&minus;x&middot;H where x is between 0.8 and 1.0.

Process for coating a carrier structure

A process for coating the flow channels in a monolithic, cylindrically shaped catalyst carrier with a coating dispersion, wherein the carrier has two end faces which are connected to each other by flow channels arranged parallel to the axis of the cylinder, by vertically aligning the axis of the cylindrical carrier, placing a predetermined amount of coating dispersion from a storage container on the upper end face of the carrier and drawing the dispersion through the flow channels under suction, removing excess coating dispersion from the flow channels by emptying the flow channels under suction, returning the excess dispersion to the storage container and fixing the dispersion coating by calcination. The coating dispersion is drawn through the flow channels under suction at a rate of flow of 0.1 to 1 m/s and after completion of passage under suction the excess coating dispersion is removed from the flow channels by applying a suction impulse from below, wherein the suction air is drawn through the flow channels under suction at a rate of flow between 40 and 1 m/s and the excess coating dispersion discharged with the air stream is separated from the air stream within a time of less than 100 ms after discharge from the catalyst carrier.

Process for coating the flow channels in a monolithic catalyst carrier with a coating dispersion

A method for partially coating a cylindrical carrier body with a coating suspension, the carrier body having a cylindrical axis, two end faces, an envelope, and an axial length L, and being provided with a series of channels extending from the first end face to the second end face. A desired coating quantity of the coating suspension is applied onto the carrier body by vertically aligning the cylindrical axis and introducing the coating suspension into the channels through the lower end face. The carrier body, measured from the lower end face, is filled with a filling volume of the coating suspension which is metered, such that the carrier body is only filled up to a height that amounts to a predetermined fraction of its length L. Subsequently, excess coating suspension is removed downward so that the desired coating quantity remains on the carrier body.

Method for partially coating a carrier body

Growing community of inventors

Mespelbrunn, Germany

Josef Piroth