Abstract: A drive assembly for a sootblower which provides a non-constant rate of rotational motors of the lance tube through the use of non-circular gears in the drive assembly. The drive assembly is used to provide a uniform or near uniform rate of progression of a jet of cleaning medium ejected from the lance tube along a surface to be cleaned.

Abstract: A drive assembly for a sootblower which provides a non-constant rate of rotational motors of the lance tube through the use of non-circular gears in the drive assembly. The drive assembly is used to provide a uniform or near uniform rate of progression of a jet of cleaning medium ejected from the lance tube along a surface to be cleaned.

Abstract: An anti-drift mechanism for a downwardly oriented port rodder for cleaning a port opening of a recovery boiler. The anti-drift mechanism prevents a cutter of the rodder from accidentally drifting from a retracted holding position into the port upon the loss of holding power to the actuator. Two embodiments are disclosed. The first is a frictional engagement with the port rodder while the second involves the use of a valve in conjuction with the actuator to trap fluid pressure and maintain the rodder in the holding position.

Abstract: A long retracting sootblower for boiler cleaning of the type having a lance tube which is advanced into and out of a boiler and simultaneously rotated, and having one or more nozzles discharging a jet of blowing medium which trace helical paths. An indexing mechanism is provided to change the positioning of the helical paths traced by the nozzles between successive actuation cycles to minimize boiler erosion and mechanical stress caused by repeated blowing medium impact against surfaces within the boiler. the indexing mechanism includes relatively slidable longitudinal advancement rack sections which cause the engaging pinion gears to index by one or more teeth upon each actuation cycle. A movable rack portion is biased by a compliant element to remain in a normal position until initial advancement of the lance carriage which causes the movable portion to be indexed with respect to the fixed portion of the rack.

Abstract: Roller supporting means for the lance tube of a long travel retracting soot blower includes a pair of castering-type roller assemblies having their castering axes non-vertical. Each roller assembly is counterweighted to such extent as to substantially statically balance the assembly about its castering axis.

Abstract: An accessory transmission conversion mechanism of the type disclosed in the U.S. Pat. No. 4,177,539, to Elting, for causing the lance tube of a long retracting soot blower to oscillate about its longitudinal axis, is provided with a lost motion driving connection between the yoke driving gear and the crank of the Scotch yoke which generates the oscillating motion. A holding portion on the gear permits locking out such lost motion when desired. When lost motion is present, the blowing path is automatically changed when the blower reverses. When locked out, the blowing pattern is changed so that the jet traces the same path in each direction of movement.