Target wall air jet for controlling combustion air

Abstract

A method of and apparatus for selective control of combustion gas flow in a furnace firing port in a furnace of the type having a plurality of firing ports, each port having a passageway for receiving combustion gas, e.g. preheated air, from a common plenum chamber, wherein the chamber includes a back or target wall in opposed spaced relationship to each of the passageways. A flow control pipe is inserted through a plenum wall directed toward the passageway between the plenum and port. A small quantity of pressurized gas, e.g. air, is injected generally along the flow path of combustion air in the plenum toward passageway to alter the amount of combustion air flowing into the port. In a preferred embodiment, combustion air is increased by injecting air through a target wall flow control pipe cocurrent with the flow to induce additional flow into the port and combustion air is decreased by injecting air countercurrent to the flow adjacent to the passageway to impede flow into the port.

Dependencies are inferred from the claim text.