Patent ID: 8997666
Filing Date: 2015-04-07
Classification: F23B,F23J,F23L

Abstract:
1. An elevated fixed-grate apparatus for use in a furnace for combusting residual wood waste product with a wide range of moisture content, said apparatus comprising: a first course of solid refractory bricks forming a base, more than one subsequent course of said solid refractory bricks arranged atop said base, said first course and each said subsequent course being arranged in a concentric manner thereby isolating underfire air located below said solid refractory bricks from overfire air located above said solid refractory bricks, each said subsequent course having an outer peripheral dimension smaller than an immediately preceding course upon which said subsequent course is placed, said first course and each said subsequent course are stacked one atop another so as to form a contiguous stepped top surface which includes an opening in a topmost one of said subsequent courses from which said residual wood waste product is supplied, said contiguous stepped top surface being solid in its horizontal direction and supporting said residual wood waste product during combustion thereof, each said course having an inner peripheral dimension such that an inner cavity is formed by said courses being stacked one atop another, said bricks each formed as an arcuate segment of less than a complete a circle, each said solid refractory brick includes integral portions therewith forming a pair of lateral ribs located at respective opposite bottom edges of each said solid refractory brick and a central rib located on a bottom center of each said solid refractory brick, each said rib extending completely across a bottom surface of each said solid refractory brick and being oriented radially relative to courses and being dimensioned in a manner sufficient to provide vertical spacing of said solid refractory brick of each said subsequent course from said solid refractory brick of said immediately preceding course, and said vertical spacing providing a horizontally arranged air passage between each said course, said horizontally arranged air passage enabling transfer of underfire air from below said solid refractory bricks to above said solid refractory bricks.