High pressure cleaning lance drive safety apparatus

A flexible cleaning lance safety apparatus is described as including a tripod support structure located close to an opening into an object to be cleaned. A flexible lance drive is fastened to the support structure for driving a high pressure fluid through a lance to the object to be cleaned. A snout tube is connected between the lance drive and an opening into the object to be cleaned. One or more micro pressure valves on each leg of the tripod support structure is operative to sense a predetermined force applied between the support structure and a support surface supporting the tripod support structure. When the predetermined force is sensed this causes the high pressure fluid to be diverted from the lance and the object to be cleaned to atmosphere.

BACKGROUND OF THE DISCLOSURE

The present disclosure is directed to high pressure fluid rotary nozzle handling systems. In particular, embodiments of the present disclosure are directed to a safety apparatus for detecting and minimizing danger to personnel from a high pressure cleaning lance inadvertently backing out of a floor or roof drain or otherwise in a situation where a back-out preventer either cannot be installed on the support structure or would be difficult to install.

What is therefore needed is a safety apparatus that can be mounted above or about the drain or other opening that facilitates simplified handling of flexible lances together with a drive that permits an operator to stand clear of the region directly above or around the drain or other opening and which precludes uncontrolled motion of a high pressure flexible cleaning lance.

SUMMARY OF THE DISCLOSURE

A flexible lance drive apparatus in accordance with the present disclosure directly addresses such needs.

One exemplary flexible lance drive apparatus in accordance with the present disclosure includes a flexible lance drive device preferably mounted to the apex of a support frame such as a tripod positioned above the opening of the object to be cleaned. The tripod rests on a horizontal support surface such as a floor, roof or tube sheet. This embodiment of the apparatus has a sensor, preferably a pressure sensing air micro valve switch positioned at the foot or bottom of each tripod leg. Each micro valve switch operates to trigger automatic and immediate bleed-off of control air pressure in the event that the weight sensed by each support leg decreases to a predetermined value. In return, the immediate bleed-off of control air pressure triggers dump, i.e. exhaust of the high pressure fluid pressure applied to a flexible cleaning lance.

An embodiment in accordance with the present disclosure may be viewed as a flexible cleaning lance safety apparatus that includes a support structure located close to, e.g., adjacent or in registry with, an opening into an object to be cleaned, a flexible lance drive fastened to the support structure for driving a lance carrying a high pressure fluid to the object to be cleaned, and one or more micro pressure valves on the support structure operative to sense a predetermined force applied between the support structure and the structure support surface. When the predetermined force is sensed, the high pressure fluid is diverted from the object to be cleaned to atmosphere. This support structure may be a tripod. At least one micro pressure valve is preferably mounted between the support surface supporting the tripod and each leg of the tripod. Each micro pressure valve is preferably connected in series with a pilot valve that is operable to quickly bleed off air pressure applied to an air pressure actuated high pressure fluid dump valve when the predetermined force is sensed. Preferably the tripod has a micro pressure valve mounted at a foot of each leg of the tripod. A snout tube is preferably mounted between the lance drive and the object to be cleaned to direct the lance and shield an operator from any fluid spray from the lance. The safety apparatus preferably further includes a plurality of micro pressure valves connected in series such that the force sensed at any one of the micro pressure valves reaching the predetermined force causes air pressure to one or more pilot valves to decrease. The one or more pilot valves operate an air actuated high pressure dump valve to divert high pressure fluid pressure applied to the flexible lance to atmosphere.

A flexible cleaning lance safety apparatus in accordance with the present disclosure may alternatively be viewed as including a tripod support structure located close to an opening into an object to be cleaned, a flexible lance drive fastened to the support structure for driving a high pressure fluid through a lance to the object to be cleaned, and one or more micro pressure valves on each leg of the tripod support structure operative to sense a predetermined force applied between the support structure and a support surface supporting the tripod support structure. When the predetermined force is sensed, the apparatus causes the high pressure fluid to be diverted from the lance and the object to be cleaned to atmosphere. Each micro pressure valve is connected in series with a pilot valve operable to bleed off air pressure applied to a dump valve when the predetermined force is sensed. The tripod has a micro pressure valve mounted at a foot of each leg of the tripod and the micro pressure valves are preferably connected in series. A snout tube is preferably mounted to the tripod directing a cleaning lance from the drive to the object to be cleaned.

A flexible cleaning lance safety apparatus in accordance with the present disclosure may be viewed as including a tripod support structure located close to an opening into an object to be cleaned, a flexible lance drive fastened to the support structure for driving a lance directing high pressure fluid to the object to be cleaned, a snout tube between the lance drive and an opening into the object to be cleaned, and one or more micro pressure valves on each leg of the tripod support structure operative to sense a predetermined force applied between the support structure and a support surface supporting the tripod support structure. When the predetermined force is sensed this causes the high pressure fluid to be diverted from the lance and the object to be cleaned to atmosphere. Each micro pressure valve is connected in series with a pilot valve. The pilot valve is operable to bleed off air pressure applied to an air actuated high pressure fluid dump valve when the predetermined force is sensed by the pilot valve.

Further features, advantages and characteristics of the embodiments of this disclosure will be apparent from reading the following detailed description when taken in conjunction with the drawing figures.

DETAILED DESCRIPTION

An exemplary drive safety apparatus100is shown inFIG. 1. For simplicity of explanation, the flexible lance itself is omitted from the Figures. The apparatus100includes a flexible lance drive110for inserting and retracting the flexible lance vertically through a snout tube130that guides the lance into and out of the drain102. This exemplary apparatus100includes a tripod support structure120and a guide sleeve or snout tube130positioned coaxially in registry with an opening into a floor drain102. The support structure120rests on a support surface104such as a floor, grating, planar tube sheet or roof. Preferably the snout tube130is adjusted so as to fit within the floor drain102about 2 inches or more below the surface104. The apparatus100may also include a collet block137between the drive110and the tube130for limiting passage of a flexible lance through the snout tube130.

Attached to each of the tripod feet122of the tripod support120is pressure sensor such as a push button micro pressure valve switch or simply “micro valve”140. Air pressure circuit diagrams for these switches are shown inFIGS. 2 through 4. Referring now toFIG. 2, for example, each of these micro pressure valves140is connected in series to a piloted valve150mounted in a box124fastened to the apex of the tripod support structure120. So long as each of the three micro pressure valves140remain pressurized, the piloted valve150remains open, providing a pressure signal or “on” signal to the high pressure water pressure actuator160on the operator's control panel (not shown inFIG. 1). So long as the pressure signal is provided to the piloted valve150, air pressure is supplied to the high pressure dump actuator160on the operator's control panel. An operator may turn on and supply high pressure water to the lance (not shown) being guided and driven via apparatus100only when air pressure is supplied to the high pressure dump actuator160. The high pressure dump actuator160

In the event that one of the tripod legs becomes unbalanced causing loss of pressure in the series connected string of micro pressure valves140to the piloted valve150, the piloted valve shifts, dumping air pressure from the high pressure water dump actuator160. This action in turn diverts high pressure water flow to the flexible lance to atmosphere rather than sending it only to the lance, by opening a dump valve (not shown). Signal loss to the piloted valve150caused by any or all of the three feet losing contact with the ground will result in loss of pressure to the micro pressure valves140. Loss of this pressure in turn, via the piloted valve150, will override an operator who may be providing an “on” signal to the high pressure water actuator170on the operator's control console, and automatically divert or dump high pressure water away from the flexible lance and its tool, thus providing an enhanced safety margin for the operator in the event of an unanticipated movement or tipping of the tripod support structure120of the safety apparatus100.

FIG. 3shows another embodiment of the air pressure control apparatus100in which an additional rapid exhaust valve180is present in series with the piloted valve150. This fast acting valve180shortens the time required for the air pressure to completely exhaust thus shortening the time between sensing a tipping of the tripod support120and the complete shutdown of fluid flow to the lance.

FIG. 4shows an alternative embodiment of the apparatus100in which two pilot valves150are arranged in parallel to reduce the bleed-down time of the air pressure in the event of one of the sensor micro valves140reaching its set point pressure. Alternatively one or more micro valves140may also be mounted on the snout tube130.

Furthermore, a back-out preventer may be fastened to the snout tube130or to the opening into the drain102to prevent a flexible lance from backing out of the drain opening or other opening into a piping system or other object being cleaned. One such back-out preventer is shown installed inFIGS. 6 and 7.

FIG. 5shows a close-up perspective view of the foot end of one of the tripod legs126. This foot end of leg126may be fastened to a dome foot member or rotatably mounted to swivel joint foot which has a dome portion128and a flat plate portion132. Plate portion132is spaced parallel to a flat base plate134. The flat base plate134is the component that actually touches the support surface104, whether it be a floor, a grate, tube sheet, or other structure. A plurality of screws136fastened to the base plate134each has a coil spring138around it that biases the plate portion132away from the base plate134.

The micro pressure valve140is fastened to the plate portion132and has a plunger142that presses against the upper surface of the base plate134. The micro valve140is set such that when the baseplate134is fully spaced by the springs138from the plate portion132, air pressure is removed from the dump actuator160. Only when the baseplate134is compressed toward the plate portion132by the weight of the leg126and its portion of the apparatus100ultimately against the support surface104will micro pressure valve140be closed. Hence the apparatus100senses when it is properly resting on the support surface. Lifting of one or more of the legs126off of the support surface104opens the micro pressure valve140causing dump of high pressure fluid as above described. Utilizing this configuration of the apparatus100permits it to be utilized on floor grating, a horizontal tube sheet, a solid floor, or virtually any other surface having three points of contact for the legs126of the tripod stand120.

FIGS. 6 and 7illustrate an alternative embodiment of a safety drive apparatus200in accordance with the present disclosure. For simplicity of explanation, again, the flexible lance itself is omitted fromFIGS. 6 and 7. The apparatus200includes a flexible lance drive210for inserting and retracting the flexible lance vertically through a snout tube230that guides the lance into and out of the drain102. This exemplary apparatus200includes a tripod support structure220and a guide or snout tube230positioned coaxially in registry with an opening into a floor drain102. The support structure220is a collapsible tripod that has a central sleeve and three collapsible legs each attached to one of the tripod feet222that rests on a support surface104. The snout tube230passes through the sleeve from the drive210. Preferably the snout tube230is adjusted so as to fit within the floor drain 1-2 inches or more below the surface104as is most clearly shown in the side view ofFIG. 7. During operation, side to side vibration or movement of the support structure200on the surface104may be small enough not to actuate the micro valve switches140. Installing the snout tube230into the opening helps maintain support structure alignment and may prevent this arrangement of the snout tube230from lateral movement or misalignment with the opening102.

Attached to each of the tripod feet222of the tripod support220is a push button micro pressure valve switch140. Each of these micro pressure valves140is connected in series to a piloted valve150mounted in a box224fastened to the apex of the tripod support structure220. So long as each of the three micro pressure valves140remain pressurized, the piloted valve150remains open, providing a pressure signal or “on” signal to the air operated high pressure water pressure dump actuator160on the operator's control panel (not shown). So long as the pressure signal is provided to the piloted valve150, air pressure is supplied to the high pressure dump actuator160on the operator's control panel. An operator may turn on the drive210and feed or retract the flexible lance through the apparatus200. However, the operator may supply high pressure water to the lance (not shown) being guided and driven via apparatus200only when air pressure is supplied to the air operated high pressure water dump actuator160.

Apparatus200is identical to apparatus100except for addition of a flexible hose guide tube231, location of a collet block237below the tripod sleeve and the drive210on the snout tube230and addition of a back-out preventer plate235around the snout tube230. In this embodiment200, the drive210is directly fastened to the upper end of the snout tube230. The collet block237is relocated low on the snout tube230below the tripod sleeve and is again utilized to prevent the flexible lance from backing up through the drive210. The back-out preventer plate235is removably fastened to the snout tube230close to the support surface104. One end of the flexible hose guide tube231is fastened to the back-out preventer plate235via a fitting233. The other end of the flexible hose guide tube231is routed up and around to feed the flexible lance down through the lance drive210. This arrangement lowers the center of mass of the apparatus200. When the lance drive210is operated to pull and/or push the flexible lance hose through the guide snout tube230the pull on the hose supply (not shown) is placed closer to, and parallel to the support surface104. This arrangement lessens the operational torque placed on the safety apparatus200during operation to reduce the potential to tip over the tripod support220. The addition of the back-out preventer235also reduces any spray and splash back out of the drain102. In addition, if a tool on the end of the flexible lance were to turn around in the pipe, the splash plate of the backout preventer235prevents such a tool from escaping due to the small gap, which would also tend to tip the support structure220causing dump of the high pressure water.

In alternative embodiments, electronic sensors such as piezoelectric strain gauges, electrical or hydraulic actuators and motors may be used in place of the air micro valve sensors, pneumatic actuators and air drive motors shown and described. A support configuration other than three legs may be utilized. For example, a wheeled structure might be provided with two, three or four wheels, one at each corner of the frame structure. In such a case, additional pressure valves would be needed, one for each leg, and the sensitivity would necessarily be somewhat modified. Alternatively, or in addition, one or more micro valves or other sensors could be attached to the snout130in such a way as to detect undue force directly applied on the snout130. Again, such micro valve(s) would be connected in series with the pilot valve150. The flexible lance drive110,210mounted on the apex of the tripod support120,220or other support frame may be other than as specifically shown. It is to be understood that the embodiments shown are but exemplary setups of the apparatus100and200in accordance with the present disclosure.

Furthermore, the apparatus100and200need not be utilized with floor or roof drains. Each may also be adapted to and applied to any piping configuration to be cleaned, so that an operator may stand clear of the access to such piping configuration during the cleaning operation while at the same time the apparatus senses and diverts fluid flow away from the flexible cleaning lance in the event of sensed pressure on the supportive frame structure reaching, i.e. decreasing to a predetermined value. While the embodiments shown are directed to an apparatus100or200positioned directly above the opening, e.g., floor drain102, other orientations are within the scope of the present disclosure. For example, where an inclined orientation is required, the micro pressure valves140on each tripod foot may be calibrated appropriately such that a change from a static, or rest, configuration, would trigger actuation of the pilot valve150with resulting release of pressure from dump actuator160.

All such changes, alternatives and equivalents in accordance with the features and benefits described herein, are within the scope of the present disclosure. Such changes and alternatives may be introduced without departing from the spirit and broad scope of this disclosure as defined by the claims below and their equivalents.