Abstract:
Disclosed are exemplary apparatus and methods for removing a fluid from an article. A guide tube is extended into the article so that a tube first end resides in a region proximate the fluid. The guide tube is a rigid, semi-rigid or flexible member, allowing the tube to circumvent obstructions in the article. A wick, made of an absorbent material, is inserted into the tube until a wick first end is proximate the tube first end and is in contact with the fluid. Capillary action draws the fluid into the wick first end, where it is transferred to an opposite, wick second end that is disposed in a collection vessel. The vessel may contain an absorbent material to speed the removal process and simplify the disposal of the fluid. After removal, the fluid may be disposed of in an environmentally conscious manner.

Description:
[0001]    This invention was made with Government support under F33657-99-D-2051-0013 awarded by the United States Air Force. The Government has certain rights in this invention. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    (1) Field of the Invention 
         [0003]    The invention relates to components preserved with fluid and more specifically to an apparatus and method for removing accumulated preservation fluid in an environmentally conscious manner. 
         [0004]    (2) Description of the Related Art 
         [0005]    Gas turbine engines typically power aircraft, ships and electrical generators. After original equipment manufacturing (OEM) and subsequent overhaul and repair (O&amp;R) shop visits, an engine is test run to break in mating parts and to ensure the engine meets operational performance limits. Since a lengthy period of time may occur between a test run and actual service use, an engine&#39;s internal and external components must be protected from corrosion. 
         [0006]    At the end of a typical test run, the engine&#39;s rotational speed is reduced to idle while the fuel supply is switched from aviation fuel to preservation fluid. A preservation fluid such as type 1010, specified in MIL-PRF-6081D or the like, is typically used in gas turbine applications. The preservation fluid coats the fuel system and other internal components, thus forming a protective barrier against corrosion. After the engine idles for a period of time with preservation fluid as the fuel source, the engine is shut down and packaged for storage and/or shipment to a customer. 
         [0007]    During extended shipment and storage periods, such as with spare engines, residual preservation fluid accumulates in pools in the lowest areas of engines due to gravity. One such area is located in the diffuser case, downstream of the fuel nozzles and upstream of the first turbine vane and blade outer air seal (BOAS). Upon subsequent engine startup, the accumulated preservation fluid can ignite, leading to oxidation damage of brand new or newly refurbished components. The BOAS segments are particularly susceptible to damage due to their close proximity to the accumulated preservation fluid. If visual inspection establishes that the BOAS segments or other components are damaged, the engine must be disassembled for repair. Engine disassembly is both time consuming and can be rather expensive. 
         [0008]    As an alternative, engines may be stored for extended periods without the use of preservation fluid. To prevent the formation of corrosion, these engines must be started at regular intervals. Periodic engine starting vaporizes accumulated condensation and purges the fuel system components of harmful corrosion. This procedure is time consuming, expensive, requires trained personnel and specialized test facilities. 
         [0009]    Draining the preservation fluid is not always feasible. Access ports are not always available in the exact area where preservation fluid accumulates. Dedicated ports for preservation fluid removal add weight, complexity and manufacturing cost to an engine. Existing plugs may be located near the preservation fluid pools, and a specialized vacuum may be used to remove the fluid. Vacuuming requires a power source, specialized equipment and extensive training for personnel to avoid collateral damage to adjacent engine components. Drain plugs and vacuums may also allow preservation fluid spillage onto the ground, creating environmental remediation concerns. 
         [0010]    What is presently needed is a simple, environmentally conscious apparatus and method for removing a fluid from an area of an article such as a diffuser case of a gas turbine engine. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    In accordance with the present invention, an apparatus and method for removing a fluid from an article are provided. 
         [0012]    In an exemplary apparatus, a guide tube includes a body, a first end and a second end. A collection vessel is disposed proximate the tube second end to serve as a reservoir for the removed fluid. A wick is disposed in the tube body with a first wick end proximate the tube first end, in contact with a fluid, and a second wick end extending into the vessel. The wick material permits capillary transfer of the fluid from the apparatus, through the wick, to the vessel. 
         [0013]    In an exemplary method, a region proximate the fluid is first exposed. A first end of a guide tube is extended into the region. A first end of a wick is then inserted into a second end of the tube and advanced into the guide tube until the first end of the wick contacts the fluid. The fluid is drawn into the first end of the wick and transferred to a second end of the wick through capillary action. The fluid is lastly collected from the second end of the wick and disposed of in an environmentally conscious manner. 
         [0014]    A primary advantage of the present invention is the ability to remove fluids from regions of an apparatus that are difficult to access. The method requires a minimal level of skilled labor and the apparatus cost is low. Once installed, the apparatus passively removes residual fluids over the duration of the storage period. Also, the fluids are able to be collected and disposed of in an environmentally conscious manner. 
         [0015]    These and other objects, features and advantages of the present invention will become apparent in view of the following detailed description and accompanying figures of multiple embodiments, where corresponding identifiers represent like features between the various figures. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0016]      FIG. 1  illustrates an exploded view of a fluid removal and collection apparatus according to an embodiment of the present invention; 
           [0017]      FIG. 2  illustrates a partial cross sectional view of a first embodiment of a guide tube of the apparatus of  FIG. 1 ; 
           [0018]      FIG. 3  illustrates a partial cross sectional view of a second embodiment of a guide tube of the apparatus of  FIG. 1 ; 
           [0019]      FIG. 4  illustrates a partial cross sectional view of a third embodiment of a guide tube of the apparatus of  FIG. 1 ; and 
           [0020]      FIG. 5  illustrates a simplified cross sectional view of the apparatus of  FIG. 1 , removing accumulated preservation fluid from a diffuser case of a gas turbine engine. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Referring first to  FIG. 1 , a fluid removal apparatus  10  broadly comprises a guide tube  12 , a wick  14  and a collection vessel  16 . The guide tube  12  directs the wick  14  to a fluid F, located in an article A, for transfer to the collection vessel  16 . Once removed, the fluid can be disposed of in an environmentally conscious manner. The wick  14  draws the fluid F pool out of the article A by capillary action. Capillary action occurs when the adhesive intermolecular forces between the fluid F and the porous wick  14  are stronger than the cohesive intermolecular forces within the fluid F itself. 
         [0022]    The guide tube  12  is a hollow, thin-walled body, having an internal passageway that is nonporous, unobstructed and as smooth as possible. The guide tube  12  directs the wick  14  around obstructions in the article A to the fluid F. Preferably, the passageway has a cross sectional shape that matches the wick&#39;s  14  cross sectional shape, but they may also be shaped differently. Although a circular shaped profile is illustrated throughout the figures, other shapes such as square and oblong would function appropriately and are also contemplated. The guide tube  12  preferably has a rigid body  18 , but the body  18  may also be semi-rigid or flexible, depending on the accessibility of the fluid F. A tube first end  20  is disposed in a region R, proximate the fluid F pool, and an opposite, tube second end  22  is disposed proximate the collection vessel  16 . The tube second end  22  includes means  24  for attaching the tube second end  22  to a lid  26  of the collection vessel  16 . Suitable attachment means  24  and other details of the guide tube  12  are described in great detail later. Between the tube first  20  and second  22  ends, the tube body  18  may have one or more straight  28  or curved  30  sections to direct the wick  14  around obstructions. 
         [0023]    The wick  14  functions as a conduit for transferring the fluid F pool from the article A to the collection vessel  16  by means of capillary action. The wick  14  is a woven, flexible or semi-rigid member made of an absorbent material. For example, the wick material may be cotton, hemp, wool, paper, or any other absorbent material known in the art. The cross sectional profile of the wick  14  is preferably the same as the guide tube body  18  and is slightly smaller to allow insertion and advancement through the entire length of the body  18  without binding. The wick  14  has a first end  32  disposed proximate the fluid F and an opposite, second end  34  disposed within the collection vessel  16 . 
         [0024]    The collection vessel  16  comprises an upper lid  26  and a lower cup  36 . As previously described, the lid  26  is affixed to the tube second end  22  by attachment means  24 . An aperture  38  through a raised flange  40  accepts the tube second end  22 . In the example shown, a groove  42  circumscribes the outer diameter of the tube second end  22 . The groove  42  accepts a set screw  44  advanced through a threaded aperture  46  in the flange  40 . The position of the guide tube  12 , in relation to the lid  26 , may be adjusted by loosening the set screw  44  and rotating the tube  12 . The flange  40  also contains means  47  for attaching the fluid removal apparatus  10  to the article A. In the example shown, a pair of female grooves  48  engage corresponding male pins  50  ( FIG. 2 ) located on the article A. The example attachment means  47  is sometimes referred to as a bayonet fitting and provides a positive attachment and precise alignment. 
         [0025]    The cup  36  collects the fluid F for later disposal in an environmentally conscious manner. The cup  36  attaches to the lid  26  at a threaded connection  52  about its open end. Clips, fasteners, or other attachment means known in the art may also be used. With the lid  26  attached to the cup  36 , the wick second end  34  extends into the cup  36 . An absorbent material  54  may be disposed in the cup  36 , surrounding a portion of the wick second end  36 . The absorbent material  54  speeds the fluid F removal process and simplifies the disposal of the collected fluid F. The absorbent material  54  may be corncob, cellulose, paper, peat moss, polypropylene or other absorbent material known in the art. The volume of the cup  36  is preferably larger than the volume of the removed fluid F to ensure complete removal without fluid F spillage. 
         [0026]      FIGS. 2-5  illustrate further details of various embodiments of a fluid removal apparatus  10 . In a first embodiment of  FIG. 2 , a lid  26  is attached to an article A by engaging pins  50  with corresponding grooves  48  in the flange  40 . The guide tube  12  is a preformed, rigid member with a body  18  comprised of both straight  28  and curved  30  portions. The preformed body  18  allows repeatable access to a region R proximate the fluid F. 
         [0027]    In another embodiment of  FIG. 3 , a lid  26  is attached to an article A by engaging pins  50  with corresponding grooves  48  in the tube second end  22 . The grooves  48  reside in an oversized region  56  of the tube second end  22 , instead of in the flange  40  as in the previous example. The guide tube  12  is a preformed, semi-rigid member with a body  18  comprised of rigid, straight  28  portions and flexible, curved  30  portions. Corrugations form the curved portions  30  in the example, but swivel joints, ball joints or other flexible means may also be used. The corrugated, curved portions  30  allow for slight adjustments of the tube  12  in order to allow access to a region R that is difficult to access with a completely rigid tube body  18 . 
         [0028]    In yet another embodiment of  FIG. 4 , a lid  26  is attached to an article A by engaging pins  50  with corresponding grooves  48  in the tube second end  22 . The grooves  48  reside in an oversized region  56  of the tube second end  22 , instead of in the lid  26  as in the first example. The guide tube  12  is a flexible member with a body  18  comprising an externally mounted manipulation system. The tube first end  20  is manipulated by a guide ring  58  affixed to one or more guy cables  60  threaded through eyelets  62  secured to the tube body  18 . Levers  64 , rotatably secured to the tube second end  22 , selectively contract or extend the guy cables  60 . Multiple levers  64  and guy cables  60  allow precise manipulation of the tube first end  20 . The enhanced manipulation of the tube first end  20  allows access to a region R that is even more difficult to access with a rigid or semi-rigid tube body  18 . 
         [0029]    In some embodiments, the guide tube  12  body  18  may be made of two or more individual segments. For example, a first segment may contain grooves  48  for engaging pins  50  to form the attachment means  47 , while a second segment may contain the straight  28  and curved  30  portions. The first segment may extend a distance away from the article A to form a sleeve for the second segment to fit within. 
         [0030]    Referring now to  FIGS. 1 and 5 , an exemplary diffuser case  66  is disposed circumferentially about a longitudinal axis  68  of a gas turbine engine. An annular combustor  70  burns fuel and preservation fluid (F) injected from fuel nozzles  72 , spaced about the diffuser case  66 . The preservation fluid F accumulates in pools at the radially lower-most region of the diffuser case  66 . This region is upstream of the first stage of turbine vanes  74  and the BOAS (not shown). An existing port  76  provides access to the combustor  70  for periodic visual inspection via a boroscope; however, an inner boss  78  prevents draining of the preservation fluid F by gravity. As was discussed earlier, ignition of the accumulated preservation fluid F may cause damage to the surrounding components and removal is necessary prior to engine starting. 
         [0031]    An exemplary method for removing a pool of preservation fluid F from the diffuser case  66  begins by exposing a region R. proximate the fluid F. In the example shown, a boroscope inspection plug (not shown) is first removed to gain access to the region R. In other examples of the method, a fuel nozzle  72  or other component may be removed to expose the region R. A tube first end  20  is then introduced through the port  76 , proximate to the region R. The guide tube  12  may or may not be affixed to the lid  26  of the collection vessel  16  at this time. Once the guide tube  12  is properly positioned, a wick first end  32  is inserted into the tube second end  22  and advanced into the tube body  18  until the wick first end  32  contacts the fluid F. A wick second end  34  is inserted in the cup  36  of the collection vessel  16 , which is attached to the lid  26  at a threaded connection  52 . The cup  36  may or may not contain an absorbent material  54  of the type previously described. The apparatus  10  is attached to the article A by attachment means  47 . In this example, the apparatus  10  is attached by engaging pins  50  with corresponding grooves  48  in the tube second end  22 , forming a bayonet fitting. Capillary action draws the fluid F into the wick first end  32  and transfers the fluid F to the wick second end  34 , where it accumulates in the cup  36 . Lastly, the accumulated fluid F is disposed of in an environmentally conscious manner. Preferably, the fluid is disposed of in compliance with all local, state, federal AND international regulations governing the handling and disposal of the fluid F. 
         [0032]    Other alternatives, modifications and variations will become apparent to those skilled in the art having read the foregoing description. For example, the fluid removal method and apparatus may be used in the manufacturing industry to remove fluids from machinery. Accordingly, the invention embraces those alternatives, modifications and variations as fall within the broad scope of the appended claims.