FLEXIBLE LANCE DRIVE APPARATUS WITH AUTOSTROKE FUNCTION

摘要

An apparatus for sensing an obstruction within a tube being cleaned and repetitively advancing and retracting a flexible high pressure fluid cleaning lance within the tube is disclosed. The method includes sensing a pneumatic supply pressure to a pneumatic lance drive motor at the motor during forward operation, sensing a pneumatic discharge pressure at the drive motor during forward operation, determining a difference between the pressures, comparing the difference to a predetermined difference threshold; reversing the drive motor direction for a predetermined time interval if the difference exceeds the threshold, and restoring forward operation after the predetermined time interval; and repeating the reversing and restoring operations until the difference no longer exceeds the predetermined difference threshold.

主权项

1. A flexible lance drive apparatus comprising:
a generally rectangular housing having an array of upper and lower drive rollers in an outer section each rotatably supported by an axle shaft passing laterally through spaced outer and inner walls defining a mid section of the housing; a drive motor within the mid section of the housing connected to each of the upper and lower drive rollers; wherein each lower drive roller shaft is rotatably supported in a fixed position and the upper rollers may be lowered against the lower rollers via a pneumatic cylinder to sandwich a flexible lance therebetween; a control console connected to the drive motor via forward and reverse pneumatic pressure supply lines, the console having forward and reverse manual controls for directing pneumatic pressure to forward and reverse ports of the drive motor; and a solenoid valve connected across the forward and reverse pressure lines operable to reverse pneumatic pressure connections to the drive motor when energized; and an automatic blockage sensor circuit having pneumatic sensing lines connected directly at the forward and reverse ports on the drive motor, wherein the circuit is operable to sense a drive motor pressure differential between the ports above a predetermined threshold and energize the solenoid valve to reverse the pneumatic pressure supply lines to the drive motor.