Hub and drive assembly for full coverage sootblower

The present invention is directed to a sootblower and particularly to a hub and drive assembly therefore capable of producing improved cleaning by directing the blowing medium over substantially all of the surface to be cleaned. Includes a hub and drive assembly in accord with the present invention converts the alternating, clockwise and counter-clockwise rotary output of a reversible drive motor to uni-directional rotary movement of the sootblower lance. Further, the hub and drive assembly of the present invention provides an incremental degree of lost rotational movement each time the direction of longitudinal movement of the lance and nozzle assembly changes. Thus, the sootblower of the present invention moves the cleaning nozzles of the sootblower through different helical paths as the lance moves in the forward and reverse directions to provide a plurality of crossed helical paths as the drive assembly steps around the hub to produce substantially full coverage cleaning of the surfaces of adjacent heat exchanger tubes.