Parameter sensing sootblower

A parameter sensing circuit configured for use in a sootblower having a retractable lance tube wherein said lance tube is carried by a carriage into and out of a combustion device, the carriage being driven by a drive motor, the sensing circuit comprising:

• means for sensing a drive motor operating parameter;
• means for measuring an elapsed time of extension of the lance tube;
• window determination means for determining a window of time required to retract the lance tube based on said measured elapsed time of extension;
• and
• motor control means for controlling the drive motor during extension and retraction of the lance tube, wherein said motor control means is configured to activate the drive motor causing the lance tube to be extended into the combustion device upon receiving a start signal, reverse the drive motor causing the lance tube to be retracted from the combustion device when the lance tube is being extended and the magnitude of said drive motor operating parameter reaches a predetermined value and turn off the drive motor when the magnitude of said sensed drive motor operating parameter reaches a predetermined value during said window of time required to retract the lance tube.

A method for controlling the extension and retraction of a retractable lance tube in a sootblower wherein said lance tube is carried by a carriage into and out of a combustion device, the carriage driven by a drive motor, said method comprising the steps of:

• extending the lance tube into the sootblower;
• monitoring a drive motor electrical parameter during said lance tube extension;
• and
• reversing said drive motor when the magnitude of said drive motor electrical parameter reaches a predetermined value indicating said lance tube has hit a hard stop.