Heated cellular structures

DETAILED DESCRIPTION According to the practice of this invention, a honeycomb structure or body of electrically conductive material, which is preheated by electrodes, is used to remove pollutants from combustion fluids.
Briefly, the structure has an inlet end face, an outlet end face, thin walls defining cells extending longitudinally therethrough, and an outer surface.
The structure is provided with a plurality of electrodes which are radially spaced around the outer surface of the structure such that electrical current can be passed to the structure through the electrodes.
In one embodiment, a device is provided for periodically regenerating a filter by burning off collected particulates which accumulate therein, such as carbon particles from diesel exhaust gas or fumes.
In this embodiment, the device is a regenerating filter construction and consists of a honeycomb structure formed of a porous metal or porous cermet or porous silicon carbide.
The structure includes a matrix of thin porous walls which define a plurality of cells extending longitudinally and mutually parallel therethrough, between the inlet and outlet end faces of the structure, the walls having substantially uniform interconnected open porosity of a volume and size sufficient to enable the fumes to flow completely through the walls and to restrain most or all of the particulates from passing completely through the walls.
In this regenerative filter construction, an inlet group of the cells open at the inlet end face are closed adjacent to the outlet end face, and an outlet group of the cells are closed adjacent to the inlet end face and open at the outlet end face, and each cell of the inlet group shares cell walls with cells of the outlet group, and each cell of the outlet group shares cell walls with cells of the inlet group.
A plurality of electrodes radially or preferably, angularly spaced around the outer surface of the structure, adjacent to the inlet end face of the structure, are secured to the outer surface, whereby electrical currents can be passed through the structure from selected pairs of said electrodes to thereby heat the porous metal honeycomb structure and burn off combustible particulates