Steam Boiler Furnace

The combustion furnace releases the heat and becomes the heat transfer system. There are three important things required for combustion to take place in the furnace: time, temperature, and turbulence. The control of the furnace draft is required to maintain a negative pressure in the furnace in a balance draft of steam boiler. This pressure is defined by steam boiler manufacturer. Negative 0.5 inches is a common control point. The control set point may be raised during inspection rounds from 0.5 inches to 1.0 inches to minimize the possibility of flame coming out of inspection doors. 

The furnace is enclosed by a system completely welded gas tight and water cooled designed to be an integral part. The water cooled furnace envelopes constitutes the principal steam generating surface and proportioned for required cooling of combustion product to predicted furnace exit temperature.

The circulation of furnace envelopes tubes is designed for unrestricted upflow  of water and steam, terminating in the steam drum where steam, terminating in the steam drum where steam separation take place. Steam-free water, sub cooled by feedwater, returns to bottom distribution headers through unheated downcomers and large diameter feed pipes.

The furnace is designed with sufficient volume to provide for complete and efficient combustion of all fuels at all loads without flame impingement on superheater elements and on furnace water walls.

No comments: