The present invention relates to a method and system for cleaning heat exchanger tube bundles and, more particularly, to a method and system for providing a safe, economical, and environmentally friendly cleaning of heat exchanger tube bundles using cleaning fluid produced on site and reprocessed on site, such that long distance transport of cleaning solution is not required.
A mobile cleaner for heat exchanger tube bundles is disclosed in commonly owned U.S. Pat. No. 5,437,296. While the prior art mobile cleaner provided an adequate cleaning of the heat exchanger tubes, it had several problems associated with its use. The first problem was that the prior art system vented some of the fumes from the cleaning solution directly into the atmosphere. Government agencies are now paying increased attention to the release of fumes into the atmosphere and have promulgated various rules and regulations concerning proper handling of vapor emissions. Another problem involved the two top doors that did not completely seal against the top of the container or with each other, allowing escape of fumes and possibly cleaning fluid. The method of cleaning with the prior art mobile unit involved transporting the cleaning fluid to the site where the cleaning would take place, cleaning, and then transporting the used cleaning material for disposal or reprocessing. The prior art mobile cleaner also required extensive set up time to change roller positions to accommodate different sized tube bundles. These and other problems associated with the prior art identify a need for a new method and system for cleaning heat exchanger tube bundles.
The present invention overcomes at least one of the problems identified in the prior art by providing a method of cleaning a heat exchanger bundle comprising the steps of: providing a mobile cleaning unit having a cleaning enclosure accessible by a top door and having a cleaning fluid reservoir; opening the top door of the cleaning enclosure to provide access thereto; loading at least one heat exchanger tube bundle into the cleaning enclosure; closing the top door of the mobile cleaning unit and pressurizing a seal positioned about top door to provide a fluid and vapor lock of the cleaning enclosure; purging oxygen from at least one of the enclosure, the cleaning fluid reservoir, and a control panels by filling at least one of the enclosure, the reservoir, and the control panels with nitrogen; and cleaning the heat exchanger tube bundle by spraying the cleaning fluid on the bundle.
At least one embodiment of the present invention also provides a system for cleaning heat exchanger tube bundles comprising: a mobile cleaning unit comprising a tube bundle receiving reservoir enclosure having a bottom, upstanding opposing sidewalls and end walls, and a door pivotally secured to one of said sidewalls; a means for moving the door to open and close the tube bundle receiving reservoir enclosure; a cleaning fluid sump in communication with the tube bundle receiving reservoir enclosure; a plurality of drive roller assemblies and guide roller assemblies positioned in the tube bundle receiving reservoir enclosure to receive the heat exchanger tube bundles; an adjustable spray means positioned in the tubular bundle receiving reservoir enclosure for spraying a cleaning fluid over the length of the heat exchanger tubular bundle; a pump and filter assembly for recirculating the cleaning fluid from the sump to the adjustable spray means; a cleaning fluid supply reservoir interconnected with the sump; a means for heating the cleaning fluid in the supply reservoir prior to recirculating through the pump and filter assembly; a means for controlling the drive roller assembly, the pump and filter assembly, and the means for heating the cleaning fluid in the cleaning fluid supply reservoir, the controlling means comprising a plurality of explosion-proof control elements housed in a cabinet, and a vapor lock seal comprising an interior chamber, the seal positioned about the top of the reservoir enclosure and sealingly engaging the door when the interior chamber of the seal is pressurized with a source of gas.
These and other advantages will be apparent upon review of the drawings and the detailed description of the invention.
This invention will now be described in further detail with reference to the accompanying drawings, in which:
Referring to
The mobile base 11 includes a main tube bundle receiving reservoir enclosure 16 having spaced, oppositely disposed sidewalls 17 and 18 integral respective end walls 19 and 20 and an interconnected bottom structure 21. The main tube bundle receiving reservoir enclosure 16 has a domed top door 22 that is pivotally secured to the upper edges of sidewall 17. The door 22 pivots inwardly towards sidewall 18 forming an enclosed sealed cleaning area within the tube bundle receiving reservoir enclosure 16 at 24.
A cleaning fluid supply reservoir 25 is positioned directly below a portion of said bottom structure 21 of the bundle receiving reservoir enclosure 16 defining an elongated rectangular tank, see
A recirculation and filter sump 27 is positioned directly adjacent the respective ends of said main tube bundle receiving reservoir enclosure 16 and the cleaning fluid supply reservoir 25. The recirculation and filtering sump 27 is in direct communication with the main reservoir 16 for receiving used cleaning fluid therefrom. The recirculation and filter sump 27 has multiple particle filter screens 28 positioned within for initial fluid filtering of the used cleaning fluid within the recirculation system.
A main pump and filter assembly 29 are on a secondary mobile base 11B which is positioned on the trailer bed 13 adjacent to and in communication with the recirculation and filter sump 27 to provide cleaning fluid under pressure to a spray nozzle assembly 30 within said main tubular bundle receiving reservoir enclosure 16.
The spray nozzle assembly 30 includes pairs of nozzle support and supply manifolds 31 and 32 extending in spaced parallel relation to one another along said respective sidewalls 17 and 18 by adjustable manifold support brackets 17A and 18a, best seen in
Each of the supply manifolds have a plurality of fixed longitudinally spaced inwardly facing spray nozzles 33 therein forming an overlapping two level spray pattern within the heat exchanger tube bundle receiving reservoir enclosure 16. The supply manifolds 31 and 32 can be rotated on their longitudinal axis within the adjustable manifold support bracket 17A and 18A so that the relative positioning of the nozzles 33 can be directed and repositioned in relation to the main tube bundle receiving reservoir enclosure 16. The pump and filter assembly 29 includes a pump 34 and a high volume filter 35 interconnected thereto by supply lines 36 and associated valving as will be well known to those skilled in the art.
A secondary pump assembly 37 is used to initially fill the heat exchanger tube bundle receiving reservoir enclosure 16 and the recirculation and filtering sump 27 from the cleaning fluid supply reservoir 25 as best seen in
Referring back to
Each of the longitudinally spaced guide channels 42 extend between sidewall angles 39A and the raised center section 38 so that each of the guide roller assemblies 41 can be moved towards the respective drive roller assembly as seen in broken lines in
Referring now to
The heat exchanger tube bundle 45 typically has an apertured end mounting plate or tubesheet 48 of an increased diameter that will register between said adjustable bearing rollers 47 of the thrust bearing assembly 46 positioning and holding the heat exchanger bundle 45 in longitudinal alignment during rotation by the drive roller assembly 40 as hereinbefore described.
Referring to
Referring now to
Referring to
In operation, the tube bundles 45 are lowered into the heat exchanger tube bundle receiving reservoir enclosure 16 and positioned on respective drive and guide roller assemblies 40 and 41 and thrust bearing assemblies 46 which have been adjusted to the required spacing for respective tube bundle as hereinbefore described. The door 22 is closed defining the enclosed area. The cleaning fluid is heated within the cleaning fluid reservoir 25 by the plurality of heaters 25A positioned within and then pumped to the sump 27 partially filling the heat exchanger tubular bundle receiving reservoir enclosure 16 to the desired level partially submerging the respective heat exchanger tube bundles 45 within. The main pump and motor assembly 29 circulates cleaning fluid from the sump 27 through a supply line 64 to the hereinbefore described manifolds 31 and 32 at approximately 1200-1500 GPM. The spray nozzle assemblies 30 provides a continuous overlapping spray pattern on the heat exchanger tube bundles 45 which are rotated on the multiple drive and guide roll assemblies 40 and 41. The cleaning fluid is thus circulated through the sump 27 and its primary filters 28 best seen in
The coking of hot process liquid that circulates around and through the exterior surfaces of the individual tubes of the heat exchanger tube bundles 45 builds up on the exterior surface of the tubes and reduces thermal transfer, thereby diminishing the efficiency of the heat exchanger tube bundles 45. Removal of the build up residue is critical requirement of the heat exchanger tube bundles for continued high efficiency use as is required.
While the exterior of the individual tubes of the heat exchanger tube bundles are cleaned using the device and method of the present invention, the interior of the heat exchanger tubes are typically cleaned internally by high pressure water and abrasive plugs (not shown) which are forced through the individual tubes as is available in common practice at the present time. The present invention may also have the benefit of softening up the build-up in the interior of the heat exchanger tubes by partially soaking the tubes in the heated cleaning fluid during the cleaning process. When the interior build-up is softened, the internal cleaning using high pressure water and abrasive plugs is easier.
Hydraulic and electrical control for the heat exchanger tube bundle cleaning apparatus are achieved by an electrical control panel 65 having a power supply cable 66 and a hydraulic control valve assembly 67. The electrical control panel 65 is completely explosion proof and is further connected to purge system 110 as discussed below.
The various operational equipment that are required to run the cleaner are positioned on the secondary mobile base 11B such as air compressor 68, etc. as best seen in
Referring back to
The present invention includes a purge system 110, depicted schematically in
The method 120 of cleaning using the heat exchanger tube bundle cleaning device 10 is now discussed with reference to
It will thus be seen that the method and system for cleaning a heat exchanger tube bundle has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.
This application is a continuation of PCT International Application Number PCT/IB2005/051909 filed Jun. 9, 2005, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/656,430, filed Feb. 24, 2005, both applications hereby incorporated by reference.
Number | Name | Date | Kind |
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3052245 | Nagle | Sep 1962 | A |
4322868 | Wurster | Apr 1982 | A |
4458704 | Higdon | Jul 1984 | A |
4509544 | Mains, Jr. | Apr 1985 | A |
5018544 | Boisture et al. | May 1991 | A |
5246023 | Breunsbach et al. | Sep 1993 | A |
5437296 | Citino | Aug 1995 | A |
5509972 | Akazawa et al. | Apr 1996 | A |
6142169 | Lees et al. | Nov 2000 | A |
6283133 | Furuta et al. | Sep 2001 | B1 |
Number | Date | Country | |
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20060185691 A1 | Aug 2006 | US |
Number | Date | Country | |
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60656430 | Feb 2005 | US |
Number | Date | Country | |
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Parent | PCT/IB2005/051909 | Jun 2005 | US |
Child | 11307816 | US |