Conversion of Single-Pass Boiler to Multi-Pass Operation

摘要

Modifications convert an existing single-pass boiler to operate with a multi-pass combustion gas flow through the flue passages of the heat exchanger of the boiler. A diverting target wall is arranged partway along the length of the original combustion chamber, and an upper draft diverter is arranged in a flue collector chamber above the flue passages, to divert some or all of the combustion gas into a multi-pass flow pattern through several flue passages of the heat exchanger in series. The modifications may further include changing the nozzle oil delivery rate and cone angle, the oil supply pressure, the draft conditions, and others. Heat extraction from the hot combustion gas to the boiler water is increased, exhaust gas temperature is decreased, and overall efficiency is increased, to result in a fuel and cost savings.

主权项

1. A system for converting an existing single-pass boiler to multi-pass flue gas flow through a heat exchanger of the boiler, comprising a diverting target wall installed partway along a length of a combustion chamber of the boiler, and an upper draft diverter installed in an upper flue collector chamber above the heat exchanger of the boiler, wherein the diverting target wall and the upper draft diverter are effective to divert at least a portion of hot flue gas resulting from combustion in the combustion chamber to flow in a multi-pass flow pattern through plural flue passages of the heat exchanger in series.