US 4,208,367 AGranted

Process and apparatus for making rod-shaped bodies from sinterable granular material

OwnerJoachim Wunninginventor

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Abstract

Granular material, gaseous fuel and air are preheated to just below the sintering temperature of the granular material. The hot granular material is passed through a mold in which a reticular device for distributing the fuel is provided to define a conical or vaulted surface with its vertex upstream, extending across the cross-section of the mold and defining the upstream end of a combustion zone into which the granular material passes after entering the mold. Air is supplied through a perforated wall and pushes the granular material as well as advancing with it to the combustion zone. Combustion of the fuel in the combustion zone thus defined brings the granular material to the sintering temperature and a fused rod of cellular structure (i.e. with small enclosed voids, generally not communicating with each other) is continuously formed that is pulled out by rolls in a pre-cooling section of the apparatus immediately downstream of the mold. The granular material must be sinterable and is preferably ceramic, such as bloating clay or waste glass.

Claims29

Dependent claims

A process for producing rod-shaped bodies of cellular structure from a sinterable granular ceramic material by passing said granular material through a mold while supplying heat thereto evenly to bring said granular material to a sintering temperature before it leaves the mold, comprising substantially concurrent performance of the steps of:

causing a mass of particles of said granular material to move in an even flow through a fixed tubular extrusion mold defining the cross-section of a desired rod-shaped body to be formed;
uniformly heating said mass of particles to the sintering temperature of the material within said mold by causing said mass to pass through a combustion zone within said extrusion mold, and which zone is defined by combustion of a fuel within the aggregation of granular material where the granular material is being compacted, said fuel being fed through said granular material in the average direction corresponding to the direction of the movement of said granular material
pulling endwise out of said extrusion mold a body of cellular sintered-together material formed by said granular material in said combustion zone, the granular material being continuously sintered onto the end of said body as it is correspondingly pulled out of said form.

Dependencies are inferred from the claim text.