Grate Structure for Solid Fuel Burners

Abstract

In one aspect, a grate segment for a burner, comprises a substantially rigid body (30) having a dispersed array of cavities (38) filled with a refractory material. In another aspect, a solid fuel gasifier includes a housing (12) defining a gasifier chamber (14), and a solid fuel inlet (21), grate structure (22, 24) in the gasifier chamber. The grate structure includes base means, a plurality of agitator segments (32) positioned relative to the base means for reciprocating movement to agitate a fuel load in the gasifier, and means to support the base means and the agitator segments so that the latter reciprocate in a direction at a substantial inclination to both horizontal and vertical. In use of the gasifier a deep burden of fuel accumulates on the grate structure and the outward stroke of the reciprocation of the agitator elements is in the overall direction of flow of the fuel burden or generally oppositely thereto.

Description

FIELD OF THE INVENTION [0001] This invention relates generally to solid fuel burners and has particular, though not exclusive, application to a solid fuel burner of the type commonly referred to as a gasifier or gasifier combustor. BACKGROUND ART [0002] A gasifier generally includes a primary combustion chamber into which solid fuel is loaded on to a grate structure on which it is first dried and gasified via controlled primary combustion. The resultant gas is then transferred into a secondary combustion chamber, which may conveniently be a cycloburner, for secondary combustion to produce a high temperature relatively clean flue gas able to be used for a variety of purposes, eg. power generation or heating. There is a small residue of inorganic matter. [0003] A gasifier of the general type to which the present invention relates is disclosed, for example in U.S. Pat. No. 4,716,842, and the technology generally is of particular interest in waste recycling, especially with an emphasis ...

AI Technical Summary

Benefits of technology

[0023] Preferably, the gasifier has a solid fuel inlet positioned generally behind the grate structure(s) relative to a general direction of projection of the grate structure and overall direction of flow of the fuel, whereby in use of the gasifier a deep burden of fuel accumulates on the grate structure and the outward stroke of said reciprocation is in the overall direction of flow of the fuel burden. Preferably this sustained reciprocating movement is effective to agitate the fuel and enhance its combustion, and to steadily and slowly stroke or convey it along the chamber.

Problems solved by technology

Problems experienced with gasifiers, as with many other high temperature furnace processes, include sintering or aggregation of solid fines, and the difficulty of achieving thorough mixing of fuel and air / gas streams.

Images