Harper International Corporation

The Carborundum Company

Bruce J Dover

Edward V McCormick

Jonathan J Kim

Thomas A Myles

Alan R Lebold

Carl Vander Weide

A purge chamber for providing a controlled atmosphere for the treatment of materials comprises a housing within which materials to be treated may be passed through and subjected to a cross-flow of purging gas entering and exiting through a multiplicity of inlets and outlets positioned along the length of the housing. Exiting gas may be recycled and re-entered in combination with fresh gas. In practice, materials to be treated may be conveyed through the chamber while the atmosphere surrounding the materials is continuously exchanged. Flapper doors, spanning the width of the chamber, are positioned along the path of travel of the materials being treated to direct the cross-flow of purging gas and prevent the entry of unwanted gases.

Purge chamber

A kiln, useful for sintering basemetal capacitors comprises an inner zone having vertically oriented gas dispersion conduits for the inlet and radial dispersion of gas and vertically oriented electrical heating elements. Each gas dispersion conduit comprises a porous or perforated inner tube for a porous or perforated outer tube concentrically positioned around the inner tube. The annular space between is filled with a porous refractory medium, such as a bulk ceramic fiber. The temperature of the inner zone is controlled by the electrical heating elements. The gas is evenly heated as it passes radially from the inner tube through the porous refractory medium and then through the outer tube. Surrounding the inner zone is a multiplicity of stacks of substantially horizontally-oriented trays on which the material or articles to be sintered or otherwise treated are placed. The circle of stacks of trays is surrounded by an outer heating zone comprising an outer ring of electrical heating elements. The outer heating zone is, in turn, surrounded by an outer wall of porous refractory insulation. The apparatus is enclosed in a water-cooled shell of heat resistant material.

Sintering kiln

A rotary calciner for the treatment such as thermal treatment of particulate solids equipped with riffle flights, each in the form of an inverted V shape. The flights are arranged in at least two rows on the inner circumferential wall of the calciner, the rows being staggered so that the apex of each riffle flight is directly beneath the space between two riffle flights in the row above. The riffle flights provide continuous mixing and improve gas-solid contact curing rotation.

Rotary calciner with mixing flights

This invention relates to a batch type rotary calcination system where the gas used to heat and chemically react a particulate material is cross-flow contacted with the particulate material. This cross-flow is achieved by locating a gas inlet and a gas outlet adjacent an apertured cylinder containing the particulate material. The apertures on the cylinder are covered by a screen designed to permit gas flow through but prevent the escape of particulate material from the system. The gas inlet and gas outlet are so positioned to provide a continuous gas cross-flow through the particulate material being treated.

Batch system cross-flow rotary calciner

A direct heat rotary calciner and method for providing improved thermal treatment of particulate material comprises a rotary tube having a plurality of screened apertures along the length thereof. Material to be treated is passed through the rotating tube and contacted during passage with a cross-flow of heated gases entering and leaving through the screened apertures. At least a portion of the internal wall of the tube may be provided with spiral flights to aid in the conveyance of the particulate material through the rotating tube.

Continuous cross-flow rotary kiln

A method of producing near net shape fusion cast refractories. The method includes the steps of continuously introducing refractory particles into a melting furnace, rapidly heating the particles, depositing the heated particles into a melt pool, continuously introducing the molten material into a mold, and continuously withdrawing a solidified body from the mold as the molten material continually solidifies. The above stated method produces a fusion cast refractory having a generally random, fine, uniform microstructure; uniform chemistry; and generally evenly distributed closed pores.

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Lockport, NY, United States of America

Bruce J Dover