Nozzle assembly
A nozzle assembly for use in cleaning tubular members of a tube-type heat exchange having a protective coating. A metal nozzle core for communicating with a source of high-pressure water is covered at an exterior portion thereof with a plastic nozzle sleeve for engagement with the heat exchanger. A circumferential ridge of the nozzle core disposed in a circumferential groove of the nozzle sleeve prevents separation of the nozzle core and nozzle sleeve during use.
The present invention relates to an apparatus for cleaning tubular members of a tube-type heat exchanger.
BACKGROUND OF THE INVENTIONTube-type heat exchangers are typically made up of a large number of tubes extending between spaced-apart tube sheets. Walls of the tubes are relied upon for transferring heat from a medium on one side of the wall to a medium on the other side. During extended use of the heat exchanger, material from the various mediums is known to collect on both inner and outer surfaces of the tubes, causing a substantial decrease in the rate of heat transfer, and a decrease in the efficiency of the device.
In order to properly maintain a heat-exchanger, surfaces of the heat exchanger tubes are periodically cleaned in order to remove any material which has accumulated on the surfaces.
The present invention is concerned with cleaning inner surfaces of the tubes. A method is known in which a brush or scraping device of a generally cylindrical shape is moved through a tube from one end to the other end so as to brush or scrape away the accumulated material. In one known method a diameter of the brush or scraper is selected to be slightly less than an inner diameter of the tube and water at a high pressure is used to move the brush or scraper through each tube. The brush or scraper is manually inserted into one end of the tube, then a nozzle, through which the high pressure water flows, is positioned and held against the end of the tube in order to direct the high pressure water through the tube to transport the brush or scrapper through the tube. The accumulated material is removed from the inner surface of the tube and flushed out the other end by the water. Such method is known to provide a very effective tube cleaning method, however, when used on certain types of heat exchangers, damage to tubes or tube sheets of the heat exchanger can result. In particular, some heat exchangers are fabricated to have a protective coating on the tubes and tube sheets in order to control corrosion of their surfaces and when the nozzle, through which the high pressure water flows, is made to contact the heat exchange, damage may result.
OBJECT OF THE INVENTIONIt is an object of the present invention to provide a means for directing a high pressure stream of water to move a cleaning device along the inner surface of heat exchanger tubes without causing damage to surfaces of the tubes or the tube sheets supporting the tubes.
SUMMARY OF THE INVENTIONThe present invention is a nozzle assembly for use in a cleaning process using cleaning devices for tubular members of a heat exchanger. The nozzle assembly has a nozzle core for communicating at an input end thereof with a source of high pressure fluid to direct same along a central axis to an output end thereof, and a nozzle sleeve, for engaging an external portion of the nozzle core at the output end. The nozzle sleeve bears against the end of the tubular member of the heat exchanger to protect the tubular member and properly locate the nozzle assembly in the tubular member during the cleaning process.
The invention will become more readily apparent from the following description of a preferred embodiment thereof shown, by way of example only, in the accompanying drawings, wherein:
The present invention is a nozzle assembly having an inner nozzle core of a high strength material for containing and directing high pressure water or other cleaning fluid, and an outer nozzle sleeve, for engaging the nozzle core, of a material that does not result in damage to heat exchanger tubes or tube sheets during a cleaning operation.
Shown inside heat exchange tube 1 is a tube cleaning brush 5 which is moved along the length of the tube in order to remove material which has accumulated on the surface of the tube during use of the heat exchanger. The brush is typically moved along the tube with use of high-pressure water and it exits the tube at the other end. In addition to a cleaning brush, scrappers or the like (not shown) can be used in the cleaning process.
The nozzle assembly of the invention is shown at 6. In carrying out the method of cleaning, the nozzle is inserted into an end of the tube 1 to direct a high-pressure stream of water through the tube to propel the brush through the tube and exit the other end. The high-pressure stream of water both propels the brush and flushes the removed material from the tube. The nozzle assembly 6 is in communication with a source of the high-pressure water (not shown) having a valve for interrupting the flow. A gun having a trigger mechanism for operating the valve, for example, can be used with nozzle assembly 6.
Nozzle assembly 6 is shown in perspective view in
Referring to
The nozzle assembly is shown assembled in the sectional view of
As shown in
An outer surface 23 of the nozzle sleeve 8, which contacts a portion of a heat exchanger tube near the heat exchanger tube sheet during the cleaning process, is tapered at an angle of about 5-10° in relation to the central axis 9 as best viewed in
In order to facilitate removal of the nozzle sleeve 8 from the nozzle core 7, recesses 24, as best shown in
While specific materials, dimensional data, and the like have been set forth for purposes of describing embodiments of the invention, various modifications can be resorted to, in light of the above teachings, without departing from Applicant's novel contributions; therefore in determining the scope of the present invention, reference shall be made to the appended claims.
Claims
1. A nozzle assembly for use in a cleaning process for tubular members of a heat exchanger, by directing a cleaning device through the tubular member using a high pressure fluid, comprising
- a nozzle core for communicating at an input end thereof with a source of high pressure fluid to direct same along a central axis to an output end thereof, and
- a nozzle sleeve, for engaging an external portion of the nozzle core at the output end, for bearing against an inner surface of the tubular member of the heat exchanger to protect the tubular member and properly locate the nozzle assembly in the tubular member during the cleaning process.
2. The nozzle assembly of claim 1, wherein
- the nozzle core is fabricated of a metal, and
- the nozzle sleeve is fabricated of a plastic.
3. The nozzle assembly of claim 2, wherein the nozzle core is fabricated of stainless steel.
4. The nozzle assembly of claim 2, wherein the nozzle sleeve is fabricated of Delrin.
5. The nozzle assembly of claim 1, wherein
- the nozzle core and the nozzle sleeve are generally cylindrical in shape, and an external portion of the nozzle sleeve is tapered to a lesser diameter in a direction toward an output end thereof.
6. The nozzle assembly of claim 1, wherein
- the nozzle sleeve defines a cylindrical bore along a central axis at an input end thereof,
- the external portion of the nozzle core at the output end thereof is cylindrical in shape, and
- the cylindrically shaped output end of the nozzle core is disposed in the cylindrical bore of the nozzle sleeve when the nozzle assembly is assembled.
7. The nozzle assembly of claim 6, wherein
- the cylindrically shaped output end of the nozzle core has disposed thereon a circumferential ridge,
- the bore of the nozzle sleeve has disposed therein a circumferential groove for engaging the circumferential ridge when the nozzle assembly is assembled, and
- the diameter of the bore of the nozzle sleeve at the input end thereof is less than the diameter of the circumferential ridge of the nozzle core so as to provide retention of the nozzle core with the nozzle sleeve when assembled.
8. A nozzle assembly for use in a cleaning process for tubular members of a heat exchanger, by directing a cleaning device through the tubular member using a high pressure fluid, comprising:
- a nozzle core for communicating at an input end thereof with a source of high pressure fluid to direct same along a central axis to an output end thereof,
- a nozzle sleeve, for engaging an external portion of the nozzle core at the output end, for bearing against an inner surface of the tubular member of the heat exchanger to protect the tubular member and properly locate the nozzle assembly in the tubular member during the cleaning process, wherein
- the external portion of the nozzle core at the output end thereof is cylindrical in shape and has disposed thereon a circumferential ridge,
- the nozzle sleeve defines a cylindrical bore along a central axis at an input end thereof, and has disposed therein a circumferential groove for engaging the circumferential ridge when the nozzle assembly is assembled by disposing the cylindrically shaped output end of the nozzle core in the cylindrical bore of the nozzle sleeve and,
- the diameter of the bore of the nozzle sleeve is less than the diameter of the circumferential ridge of the nozzle core so as to provide retention of the nozzle core with the nozzle sleeve when assembled.
Type: Application
Filed: Feb 22, 2007
Publication Date: Sep 25, 2008
Inventors: Daniel R. Patterson (Oakmont, PA), Jeremy A. Watt (Pittsburgh, PA)
Application Number: 11/709,573
International Classification: F28G 1/16 (20060101);