1. Field
This subject matter relates generally to the cleaning of industrial equipment, and more particularly, to an apparatus for controlling the movement of one or more lances for cleaning heat exchangers, piping, tubing and other equipment found in industrial facilities.
2. Description of the Related Art
Heat exchangers are used in industrial facilities. Over time, these heat exchangers tend to develop residue on the surfaces of the tubes, tube sheets, tube support plates and other internal structural parts. This residue can have an adverse affect on the operational performance of the exchangers. The same problem can arise for piping, tubing and other equipment found in industrial facilities. A cleaning method for this equipment involves the controlled application of high pressure water and/or chemical streams to the affected areas of the equipment. One or more cleaning lances can be utilized to supply the high pressure water and/or chemical streams to the equipment.
In accordance with the illustrative embodiments hereinafter described, an apparatus for advancing a cleaning lance is provided. The apparatus can include a drive unit having one or more drive wheels disposed thereon, an idler unit having one or more idler wheel disposed thereon, an opening between the drive wheels and the idler wheels such that the cleaning lance is positionable in the opening, a contact surface on the idler wheels for contacting the cleaning lance and applying pressure to the cleaning lance, and a contact surface on the drive wheels for contacting the cleaning lance and applying frictional force to the cleaning lance such that the cleaning lance is advanced upon rotational movement of the drive wheel.
The apparatus can further include at least one channel formed in the drive wheel for engaging the cleaning lance. The channel can include a pair of retaining walls forming an angle therebetween. The channel can also include a single curved, circumferential wall. The idler unit can be adjustable between an elevated position and a lowered position, whereby the cleaning lance sits in the opening between the drive wheels and the idler wheels when the idler unit is in the elevated position, and the drive wheels and the idler wheels contact the cleaning lance when the idler unit is in the lowered position.
A method of advancing a cleaning lance is also provided. A plurality of drive wheels are provided which are capable of rotational movement, the drive wheels each having a contact surface. A plurality of idler wheels are also provided which are capable of rotational movement, the idler wheels each having a contact surface. The cleaning lance is contacted with the contact surface of the idler wheels and pressure is applied to the cleaning lance. The cleaning lance is also contacted with the contact surface of the drive wheels and frictional force is applied to the cleaning lance such that the cleaning lance is advanced upon rotational movement of the drive wheels.
The drive wheels and/or idler wheels can display certain desired grip and slip properties with respect to the cleaning lance. For example, the drive wheels and/or idler wheels can grip the cleaning lance firmly enough to promote movement of the cleaning lance through the driving apparatus, but also, the drive wheels and idler wheels can slip with respect to the cleaning lance if the forward or reverse movement of cleaning lance somehow becomes restricted due to resistance in the equipment being cleaned.
In an illustrative embodiment, a method of removing an obstruction in a heat exchanger tube using a cleaning lance is provided. One or more drive wheels are provided which are capable of rotational movement. The drive wheels each have a contact surface thereon. A contact surface of the cleaning lance is contacted or engaged with the contact surfaces of the drive wheels. Frictional force is applied to the contact surface of the cleaning lance upon rotational movement of the drive wheels, such that the contact surfaces of the drive wheels grip the contact surface of the cleaning lance and the cleaning lance is advanced towards the obstruction in the heat exchanger tube. The obstruction in the heat exchanger tube is engaged, meaning, for example, that the cleaning lance either contacts the obstruction or delivers water or cleaning fluid to the obstruction. The rotational movement of the drive wheels is continued while the cleaning lance engages the obstruction, such that the contact surfaces of the drive wheels slip against the contact surface of the cleaning lance while the obstruction is removed or substantially removed from the heat exchanger tube. When these contact surfaces slip against each other, the surfaces are not torn or otherwise damaged. After cleaning is complete, frictional force is applied to the cleaning lance upon rotational movement of the drive wheels such that the contact surfaces of the drive wheels regrip the contact surface of the cleaning lance and the cleaning lance is moved with respect to the heat exchanger tube.
While certain preferred illustrative embodiments will be described herein, it will be understood that this description is not intended to limit the subject matter to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the subject matter defined by the appended claims.
Referring now to
In an illustrative embodiment as illustrated in
Idler unit 30 can include one or more idler wheels 45. Idler wheels 45 can preferably rotate in either a clockwise or counterclockwise direction, as desired. Idler unit 30 can be positioned adjacent to drive unit 25 (See
As illustrated in
Preferably, there are two idler wheels 45 for each drive wheel 40. Idler wheels 45 and drive wheel 40 are preferably offset at approximately 15 degrees, although other offset angles can also be utilized. When pressure is applied to lance 15 by idler wheels 45 and drive wheel 40, the idler wheels 45 can force lance 15 on a slight radius around the top section of drive wheel 40. Having two idler wheels 45 offset from one drive wheel 40 can provide 4 to 5 times the surface area contact than having one idler wheel 45 pushing from directly overhead, in certain illustrative embodiments. As illustrated in
In certain illustrative embodiments, the rotational movement of idler wheels 40 is not directly powered by a motor, an electrical power source, or any other power source. Instead, the rotational movement of idler wheels 40 results from their direct contact with cleaning lance 15. As cleaning lance 15 contacts drive wheels 40 and is advanced or retracted through apparatus 10 due to the rotational movement of drive wheels 40, lance 15 contacts idler wheels 45 and causes idler wheels 45 to rotate. Idler wheels 45 apply pressure to cleaning lance 15 and prevent cleaning lance 15 from being disengaged from drive wheels 40.
In certain illustrative embodiments, drive wheels 40 and/or idler wheels 45 can display certain desired grip and slip properties with respect to cleaning lance 15. For example, drive wheels 40 and/or idler wheels 45 can grip cleaning lance 15 firmly enough to promote movement of cleaning lance 15 through driving apparatus 10, but also, drive wheels 40 and idler wheels 45 can slip with respect to cleaning lance 15 if the forward or reverse movement of cleaning lance 15 somehow becomes restricted. For example, if cleaning lance 15 encounters a plug or restriction in a tube of heat exchanger 20 such that the lance 15 cannot advance forward, drive wheels 40 can continue to rotate, but will preferably slip over the surface of cleaning lance 15 so that cleaning lance 15 would not become entangled or otherwise damaged.
One or more grooves or channels 60 may be formed on the outer surface of the drive wheels 40 and/or idler wheels 45 of driving apparatus 10. As illustrated in
The size of cleaning lance 15 may determine the shape of channel 60 that is preferably utilized. For example, for illustrative purposes only, a lance 15 having a relatively smaller size (for 2-5 inch pipes) may require a V-shaped channel, as only two contact points may be needed between cleaning lance 15 and drive wheels 40 and/or idler wheels 45 to provide the desired grip and slip properties. Alternatively, a lance 15 of relatively larger size (for 5-60 inch pipes) which can carry higher volumes of water and/or cleaning materials may require a curved, circumferential shaped channel, as more than two contact points may be needed between cleaning lance 15 and drive wheels 40 and/or idler wheels 45 to provide the desired grip and slip properties, such as increased grip when trying to advance or retract a high pressure line.
In general, driver assembly 10 is adjustable and can be utilized with a variety of sizes of cleaning lances 15, including but not limited to 1/16″, ⅛″, ¼″ and 9/16″, without any unnecessary reassembly, exchanging of parts or mechanical changes. Channels 60 in drive wheels 40 and idler wheels 45 can contact various sizes of lances 15. For example, smaller size lances 15 can sit deeper in channel 60 and larger size lances 15 can fit higher up in channel 60. In an illustrative embodiment, channel 60 can be sized at 50 degrees to accommodate ⅛″ to 9/16″ flex lances. Further, drive wheels 40 preferably have enough stroke to handle various sizes of lances 15 in certain illustrative embodiments.
Drive wheels 40 and idler wheels 45 of driver assembly 10 can provide sufficient grip and pressure on cleaning lance 15 to advance or retract cleaning lance 15 while preventing unnecessary slippage. At the same time, the surfaces of drive wheels 40 and idler wheels 45 will not damage lance 15 when some minimal slippage and/or friction does occur, in certain illustrative embodiments. For example, drive wheels 40 and/or idler wheels 45 may be formed of compound rubber, polyethylene or other polymer material, or have a coating of such material formed thereupon.
In certain illustrative embodiments, driving apparatus 10 can feed a flexible lance 15 at speeds up to 30 inches per second. Drive wheels 40 can preferably slip when a nozzle end of lance 15 meets or contacts a plug in a tube of exchanger 20. By adjusting the tension on idler wheels 45, a user can control the thrust of lance 15 against a potential plug. As lance 15 works through the plug, lance 15 will continue to travel through the tube in exchanger 20 until the plug is removed and apparatus 10 can back up to desired full speed setting. Apparatus 10 can allow for control of slippage of lance 15 between drive wheels 40 and idler wheels 45 without damaging lance 15, and can provide enough grip so that lance 15 only slips when desired.
In certain illustrative embodiments (see
Further, the position of idler unit 30 can be adjusted with respect to the position of drive unit 25. For example, the distance between drive wheels 40 and idler wheels 45 can be adjustably controlled by the user as desired. In an illustrative embodiment, idler unit 30 can be moved to a spaced apart, raised or open position (
One or more adjustment units 35 can be disposed adjacent to idler unit 30, and can be utilized to tighten and secure cleaning lance 15 between drive wheels 40 and idler wheels 45 when idler unit 30 is in the spaced together, lowered or closed position. For example, as illustrated in
In an illustrative embodiment, when idler unit 30 is in the raised or open position (
As illustrated in
In certain illustrative embodiments, driving apparatus 10 can be utilized to control the cleaning movements of a plurality of cleaning lances 15. For example, in the illustrative embodiments shown in
Driving apparatus 10 can have a plurality of front hose guides 50A, 50B and 50C and a plurality of rear hose guides 55A, 55B and 55C to guide lances 15A, 15B and 15C (not shown), respectively. One or more of lances 15A, 15B and 15C may also have a mechanical stop (not shown) disposed thereupon, such that if the mechanical stop contacts apparatus 10, the lance 15 having the stop will no longer advance or retract, but the other lances 15 will continue to advance or retract with respect to exchanger 20.
Advantageously, cleaning lance 15 is not clamped or otherwise retained onto driving wheel 40 or idler wheel 45, or within channel 60. Instead, lance 15 is capable of slipping along the surface of driving wheel 40 and/or idler wheel 45 while drive wheel 40 and/or idler wheel 45 continue to rotate. Further, drive wheel 40 and/or idler wheel 45 do not completely or substantially surround lance 15 or contact lance 15 along its entire length within apparatus 10. Driving apparatus 10 does not require any unnecessary reassembly or exchanging of parts, and can provide sufficient grip and pressure on cleaning lance 15 while preventing unnecessary slippage. Driving apparatus 10 is easy to use in the field. In certain illustrative embodiments, apparatus 10 has a complete sealed gearbox with no grease fittings. Further, drive wheels 40 are the only wear item, and can be changed easily.
In certain illustrative embodiments, drive wheels 40 and/or idler wheels 45 may be covered, or partially covered, with a belt to form a conveyer track, which would allow for additional surface area to contact cleaning lance 15.
It is to be understood that the subject matter is not limited to the exact details of construction, operation, exact materials, or illustrative embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. Accordingly, the subject matter is therefore to be limited only by the scope of the appended claims.
This Application claims the benefit, and priority benefit, of U.S. Provisional Patent Application Ser. No. 61/290,985, filed Oct. 15, 2009, entitled “Driving Apparatus for Heat Exchanger Tube Cleaning Lance,” and U.S. Provisional Patent Application Ser. No. 61/304,618, filed Feb. 15, 2010, entitled “Driving Apparatus for One or More Heat Exchanger Tube Cleaning Lances,” both of which are incorporated herein in their entireties.
Number | Date | Country | |
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61290985 | Dec 2009 | US | |
61304618 | Feb 2010 | US |