Abstract: A low frequency sound generator is depicted in FIG. 1, having a resonator tube with an open end and a closed end, with a pulsing mechanism for admitting puffs of compressed gas into the closed end for purposes of producing sound waves out of the open end. The pulsing mechanism resides inside, and is movable along the axis of the resonator tube at the closed end, providing the means of closure for said resonator tube. The axial position of the pulsing mechanism is set through adjusting means, and determines the effective length of the resonator tube, thereby controlling the resonant frequency of the emitted sound.

Abstract: A sootblower includes a supply tube for delivering fluid to a concentrically mounted lance tube. The lance tube reciprocates into and out of a boiler delivering fluid to clean the inside surface. Deformable packing between the inside surface of the lance tube and the outside surface of the supply tube prevents the escape of the cleaning fluid from the system. A follower gland is biased into engagement with the packing to maintain its seal when the packing wears. The bias is provided by a plurality of coil springs trapped between a pair of plates, flanges or washers suitably connected to the gland. A plurality of covered apertures in one of the flanges allows the insertion or removal of some of the springs to provide the desired degree of compression to the packing.

Abstract: An externally adjustable restriction control assembly for a poppet valve. The restriction control assembly is actuated through rotation of the valve stem. Upon rotation of the valve stem, a restriction control disc, threadably mounted to the valve stem guide, is moved toward or away from a seat provided within the housing. Movement of the restriction control disc thereby adjusts the effective cross-sectional flow area through the valve.

Abstract: A lance tube for use in long retracting cleaning devices of the soot blower type which in operation discharge jets of liquid against the fouled surfaces of heat exchangers such as the slag-coated surfaces of boiler tubes and the like incorporates a light weight hollow filler tube mounted in the lance tube by a helical spacer rib.