Flexible lance drive apparatus with autostroke function

A flexible high pressure fluid cleaning lance drive apparatus comprising:

• at least one drive motor that provides a driving force for advancing and retracting one or more flexible lance hoses;
• a first sensor that monitors the drive motor for determining an expected feed distance of the one or more flexible lance hoses;
• a plurality of second sensors for determining an actual feed distance of each flexible lance hose of the one or more flexible lance hoses;
• and
• a first comparator coupled to the first sensor and each second sensor, wherein the first comparator is operable to determine a mismatch between the expected feed distance of the one or more flexible lance hoses and the actual feed distance of each flexible lance hose.

A flexible high pressure fluid cleaning lance drive apparatus comprising:

• at least one drive motor that provides a driving force for advancing and retracting one or more flexible lance hoses;
• a first sensor that monitors the drive motor for determining an expected feed distance of the one or more flexible lance hoses;
• a plurality of second sensors for determining an actual feed distance of each flexible lance hose of the one or more flexible lance hoses;
• a first comparator coupled to the first sensor and each second sensor, wherein the first comparator is operable to determine a mismatch between the expected feed distance of the one or more flexible lance hoses and the actual feed distance of each flexible lance hose;
• and
• a second comparator coupled to each of the second sensors operable to determine a mismatch between the actual feed distance of each flexible lance hose.

A method of clearing an obstruction with a flexible high pressure fluid cleaning lance drive apparatus that includes a flexible lance hose, the method comprising:

• generating a command signal to cause a drive motor to advance the flexible lance hose through a tube;
• identifying the obstruction in the tube based on a comparison of an expected feed distance of the flexible lance hose and an actual feed distance of the flexible lance hose;
• initiating an autostroke sequence of operations in response to identifying the obstruction, wherein the autostroke sequence of operations includes operating the drive motor in a reverse direction to at least partially retract the flexible lance hose and then operating the drive motor in a forward direction to re-advance the flexible lance hose through the tube;
• and
• repeating the identifying step and the initiating step until the obstruction is cleared.