AUTO-INDEXING LANCE POSITIONER APPARATUS AND SYSTEM

• US 20200132402A1
• Filed: 10/24/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: StoneAge Incorporated (Mh Sub I LLC)
• Original Assignee: StoneAge Incorporated (Mh Sub I LLC)
• Inventors: Schneider, Timothy, Markham, Adam, Schneider, Joseph A., Howell, Scott, Szabo, Daniel, Montoya, Cody R.
• Granted Patent: US 11,441,856 B2
• Time in Patent Office: Days
• CPC Class Codes: B08B 9/0325 Control mechanisms therefor
• CPC Class Codes: B08B 9/0433 provided exclusively with fluid jets as cleaning tools
• CPC Class Codes: F28G 1/163 from internal surfaces of heat exchange conduits
• CPC Class Codes: F28G 15/003 Control arrangements
• CPC Class Codes: F28G 15/04 Feeding and driving arrangements, e.g. power operation
• CPC Class Codes: F28G 15/08 Locating position of cleaning appliances within conduits

Abstract

A system and an apparatus for positioning a plurality of flexible cleaning lances includes a frame removably fastened parallel a tube sheet of a heat exchanger. The apparatus includes a smart lance tractor drive for advancing and retracting one or more lance hoses through one or more lance guide tubes into tubes penetrating through the heat exchanger tube sheet, a controller, one or more AC induction sensors on the tubes operable to sense holes in the tube sheet, and a tumble box connected to the controller operable to generate electrical power to the AC induction sensor from an air pressure source, supply electrical power to the controller and distribute pneumatic power to pneumatic motors for positioning the tractor drive on the positioner frame. The tractor drive includes sensors for detection of mismatch between expected and actual lance positions and automated drive reversal operation to remove blockages within tubes being cleaned.

Claims

1. A flexible high pressure fluid cleaning lance drive apparatus comprising:

a housing;

at least one drive motor having a drive axle in the housing carrying a cylindrical spline drive roller;

a plurality of cylindrical guide rollers on fixed axles aligned parallel to the spline drive roller, and wherein a side surface of each guide roller and the at least one spline drive roller is tangent to a common plane between the rollers;

an endless belt wrapped around the at least one spline drive roller and the guide rollers, the belt having a transverse splined inner surface having splines shaped complementary to splines on the spline drive roller;

a bias member supporting a plurality of follower rollers each aligned above one of the at least one spline drive roller and guide rollers, wherein the bias member is operable to press each follower roller toward one of the spline drive rollers and guide rollers to frictionally grip at least one flexible lance hose when the at least one flexible lance hose is sandwiched between the follower rollers and the endless belt;

a first sensor coupled to one of the drive roller or one of the guide rollers for sensing position of the endless belt;

a second sensor coupled to a first one of the follower rollers for sensing position of the first follower roller relative to a first flexible lance hose sandwiched between the first follower roller and the endless belt; and

a first comparator coupled to the first and second sensors operable to determine a first mismatch between the first follower roller position and the endless belt position.

2. The apparatus according to claim 1 further comprising a third sensor coupled to a second one of the follower rollers for sensing position of the second one of the follower rollers relative to a second flexible lance hose sandwiched between the second one of the follower rollers and the endless belt.

3. The apparatus according to claim 2 further comprising a second comparator operable to compare the second follower roller position to the endless belt position and determine a second mismatch between the second follower roller position and the endless belt position.

4. The apparatus according to claim 3 further comprising a controller coupled to the first comparator and the second comparator operable to initiate an autostroke sequence of operations upon the first mismatch and second mismatch differing by a predetermined threshold.

5. The apparatus according to claim 2 further comprising a fourth sensor coupled to a third one of the follower rollers for sensing position of the third one of the follower rollers relative to a third flexible lance hose sandwiched between the third one of the follower rollers and the endless belt.

6. The apparatus according to claim 5 further comprising a third comparator operable to compare the third follower roller position to the endless belt position and determine a third mismatch between the third follower roller position and the endless belt position.

7. The apparatus according to claim 6 further comprising a controller coupled to the first comparator, the second comparator and the third comparator operable to initiate an autostroke sequence of operations upon any one of the first, second and third mismatches exceeding a predetermined threshold.

8. The apparatus according to claim 7 wherein the controller is operable to modify clamping pressure if the first, second and third mismatches exceed a different predetermined threshold.

9. The apparatus according to claim 1 wherein the sensors are quadrature encoders.

10. An apparatus for cleaning tubes in a heat exchanger comprising:

a lance positioner frame configured to be fastened to a heat exchanger tube sheet;

a flexible lance drive fastenable to the frame configured for guiding at least one flexible cleaning lance through the lance drive into a tube penetrating through the tube sheet, wherein the lance drive includes a motor coupled to a drive roller driving a belt engaging the at least one flexible cleaning lance, a first sensor coupled to the drive roller, and a follower roller riding on the at least one flexible cleaning lance, the follower roller having a follower roller sensor thereon sensing position and direction of movement of the flexible cleaning lance;

a control box communicating with the motor in the lance drive for controlling operation of the lance drive;

a tumble box for manipulating valves including a dump valve for maintaining cleaning fluid pressure to the at least one flexible cleaning lance when the dump valve is energized and diverting cleaning fluid pressure to atmosphere when the dump valve is deenergized; and

a controller coupled to the follower roller sensor configured to sense flexible lance position and sense a reversal of flexible lance movement direction, wherein the controller is operable to send a signal to the tumble box to deenergize the dump valve upon sensing the reversal of direction.

11. The apparatus according to claim 10 wherein the controller is operable to sense a mismatch between position of the at least one flexible cleaning lance and lance drive belt position.

12. The apparatus according to claim 10 wherein the follower roller sensor includes a quadrature encoder.

13. An apparatus for cleaning tubes in a heat exchanger comprising:

a lance positioner frame configured to be fastened to a heat exchanger tube sheet;

a flexible lance drive fastenable to the frame, the lance drive having one or more lance guide tubes positioned adjacent and perpendicular to a face of the tube sheet wherein each guide tube is configured for guiding a flexible cleaning lance from the lance drive into a tube penetrating through the tube sheet;

a controller communicating with motors on the positioner frame and the lance drive for controlling the lance drive;

a tumble box for manipulating air valves contained therein;

an air pressure supply connected to the tumble box; and

an inductive sensor fastened to a distal end of at least one of the one or more lance guide tubes for detecting presence of holes in the tube sheet.

14. The apparatus according to claim 13 wherein the inductive sensor includes a transmit coil around the distal end of each of the one or more lance guide tubes.

15. The apparatus according to claim 13 wherein the inductive sensor includes a transmit coil around the distal end of at least one of the one or more lance guide tubes and a plurality of receive coils positioned laterally around the distal end of the at least one of the one or more lance guide tubes.

16. The apparatus according to claim 13 wherein the controller is configured to process signals from the inductive sensor, determine a hole location from the processed signals, control the insertion and retraction of the one or more lances in the holes located, and move the lance drive on the lance positioner frame until a new hole location is sensed, in accordance with a predetermined software sequence.

17. The apparatus according to claim 16 wherein the controller is contained within a control box connected to the tumble box.

18. The apparatus according to claim 13 further comprising an inductive coupled hole location sensor fastened to the lance drive, the hole location sensor comprising:

a cleaning lance guide tube fastened to the lance drive, the guide tube having a distal end;

a transmit coil at the distal end of the guide tube;

a plurality of receive coils spaced around and outside of the distal end of the guide tube;

a power source connected to the transmit coil operable to produce a current through the transmit coil; and

an analog processor connected to each of the receive coils operable to receive and process eddy currents magnetically induced in the receive coils.

19. The apparatus according to claim 18 wherein the transmit coil is wrapped around the distal end of the guide tube.

20. The apparatus according to claim 19 wherein the receive coils are equally spaced around and outside the transmit coil.