Sootblower with lance bypass flow.

摘要

A sootblower (10) for use in cleaning heat exchanger surfaces in which a drain (60,36) is provided for selectively draining a portion of the blowing medium from the sootblower lance tube (12) for discarding externally of the heat exchanger. The lance tube drain (60,36) enables the discharge of blowing medium from the lance tube (12) into the heat exchanger to be reduced during portions of a cleaning cycle in which the lance tube nozzles (52) are not directed toward a surface to be cleaned yet enabling a minimum flow of blowing medium through the lance tube (12) for cooling or other purposes without discharging the minimum flow of blow medium into the heat exchanger. <IMAGE>