CA2274882A1 - Field serviceable fill tube for use on heat pipes - Google Patents
Field serviceable fill tube for use on heat pipes Download PDFInfo
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- CA2274882A1 CA2274882A1 CA002274882A CA2274882A CA2274882A1 CA 2274882 A1 CA2274882 A1 CA 2274882A1 CA 002274882 A CA002274882 A CA 002274882A CA 2274882 A CA2274882 A CA 2274882A CA 2274882 A1 CA2274882 A1 CA 2274882A1
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- heat pipe
- fill tube
- valve means
- disconnecting valve
- heat
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Abstract
A field serviceable fill tube apparatus for use on a heat pipe employs a quick-discon fitting on one end of the heat pipe to facilitate filling, sealing and servicing the heat pipe, during manufacture and afterwards in the field.
Description
FIELD SERVICEABLE FILL TUBE FOR USE ON HEAT PIPES
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to the field of heat pipes and, in particular v new and improved method and apparatus for filling, sealing, and field servicing heat pipes Larger size water/carbon steel heat pipes generally incorporate fill tubes through wt the working fluid is passed into the heat pipes, and through which the heat pipes are placed ur vacuum. In some cases, a union is used to allow for venting of non-condensible gases from heat pipes after some period of service.
The use of a standard heat pipe fill tube is shown schematically in Fig. 1. Dm manufacture of the heat pipe 10, one end of a fill tube 12 is welded to a hemispherica elliptical end cap 14 by means of a weld 16. The heat pipe 10 is then filled with a working f schematically indicated at 18, degassed and evacuated to a "hard" vacuum. The heat pipe 1 then sealed via a tube crimp 20 and a weld 22 at the other end of the fill tube 12. Fig. 2 sh the use of a union or coupling generally designated 30, in combination with two fill tube primary fill tube 32 and a secondary fill tube 34. During manufacture of the heat pipe 10, end of the primary fill tube 32 is welded to the end cap 14 and the other end is welde externally threaded portion 36 of union 30. The secondary fill tube 34 is then connected to primary fill tube 32 via internally threaded portion 38 of union 30. A typical conical bush 40 fits on a portion 42 of the secondary fill tube 34 within the union or coupling 30 to make seal. The heat pipe 10 is again filled with the working fluid 18, degassed and evacuated t "hard" vacuum. The heat pipe 10 is then sealed via a tube crimp 44 and sealing weld 46 on secondary fill tube 34.
The designs shown in Figs. 1 and 2 have several drawbacks because each provides several possible failure points; i.e., at welds 16, 22, 46 and at tube crimp 20, 44. In Fig. 1, crimp 20 reduces the strength of the fill tube 12, the heat pipe 10 cannot be vented of n~
condensible gas after a period of service, and the sampling of non-condensible gas and making of pressure measurements from a heat pipe 1 () requires penetration of the fill tube wall, rendering it unusable as a pressure boundary. In Fig. 2, five possible failure points ex i.e., at welds 16, 46, at tube crimp 44, and at the seal within union 30.
Additionally, ventin~
the heat pipe 10 in the field is cumbersome, and sampling of non-condensible gas and press measurements from the heat pipe 10 again requires penetration.of the primary 32 or second 34 fill tube wall thus rendering either of them unusable as a pressure boundary. In particu once any fill tube 12 or 32 is penetrated, the entire heat pipe 10 must be replaced beca restoration of the heat pipe 10 in the field is not currently possible.
The manufacturing process for heat pipe 10 also affects the type of fill tube apparatus t can be placed on the end of the heat pipe 10 itself. Fig. 2 represents one known heat-pipe construction. It is important to note that some steps in the general manufacturing procedure this construction involve, inter al ia, spinning the heat pipe 1 D while the fill tube apparatu attached. The manufacturing procedure for the heat pipes thus impacts the type of fill t assembly that can be used because any type of fitting or closure device on the end of the prim fill tube 32 must be axially symmetrical with respect to a longitudinal axis of the heat pipE
so that no excessive moment arms occur during spinning of the heat pipe 10.
This requiren precludes use of a typical T-type valve having a valve stem and handle which would protr at an angle from the longitudinal centerline of the heat pipe 10. In addition, such valves cc loosen due to vibration during service.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to the field of heat pipes and, in particular v new and improved method and apparatus for filling, sealing, and field servicing heat pipes Larger size water/carbon steel heat pipes generally incorporate fill tubes through wt the working fluid is passed into the heat pipes, and through which the heat pipes are placed ur vacuum. In some cases, a union is used to allow for venting of non-condensible gases from heat pipes after some period of service.
The use of a standard heat pipe fill tube is shown schematically in Fig. 1. Dm manufacture of the heat pipe 10, one end of a fill tube 12 is welded to a hemispherica elliptical end cap 14 by means of a weld 16. The heat pipe 10 is then filled with a working f schematically indicated at 18, degassed and evacuated to a "hard" vacuum. The heat pipe 1 then sealed via a tube crimp 20 and a weld 22 at the other end of the fill tube 12. Fig. 2 sh the use of a union or coupling generally designated 30, in combination with two fill tube primary fill tube 32 and a secondary fill tube 34. During manufacture of the heat pipe 10, end of the primary fill tube 32 is welded to the end cap 14 and the other end is welde externally threaded portion 36 of union 30. The secondary fill tube 34 is then connected to primary fill tube 32 via internally threaded portion 38 of union 30. A typical conical bush 40 fits on a portion 42 of the secondary fill tube 34 within the union or coupling 30 to make seal. The heat pipe 10 is again filled with the working fluid 18, degassed and evacuated t "hard" vacuum. The heat pipe 10 is then sealed via a tube crimp 44 and sealing weld 46 on secondary fill tube 34.
The designs shown in Figs. 1 and 2 have several drawbacks because each provides several possible failure points; i.e., at welds 16, 22, 46 and at tube crimp 20, 44. In Fig. 1, crimp 20 reduces the strength of the fill tube 12, the heat pipe 10 cannot be vented of n~
condensible gas after a period of service, and the sampling of non-condensible gas and making of pressure measurements from a heat pipe 1 () requires penetration of the fill tube wall, rendering it unusable as a pressure boundary. In Fig. 2, five possible failure points ex i.e., at welds 16, 46, at tube crimp 44, and at the seal within union 30.
Additionally, ventin~
the heat pipe 10 in the field is cumbersome, and sampling of non-condensible gas and press measurements from the heat pipe 10 again requires penetration.of the primary 32 or second 34 fill tube wall thus rendering either of them unusable as a pressure boundary. In particu once any fill tube 12 or 32 is penetrated, the entire heat pipe 10 must be replaced beca restoration of the heat pipe 10 in the field is not currently possible.
The manufacturing process for heat pipe 10 also affects the type of fill tube apparatus t can be placed on the end of the heat pipe 10 itself. Fig. 2 represents one known heat-pipe construction. It is important to note that some steps in the general manufacturing procedure this construction involve, inter al ia, spinning the heat pipe 1 D while the fill tube apparatu attached. The manufacturing procedure for the heat pipes thus impacts the type of fill t assembly that can be used because any type of fitting or closure device on the end of the prim fill tube 32 must be axially symmetrical with respect to a longitudinal axis of the heat pipE
so that no excessive moment arms occur during spinning of the heat pipe 10.
This requiren precludes use of a typical T-type valve having a valve stem and handle which would protr at an angle from the longitudinal centerline of the heat pipe 10. In addition, such valves cc loosen due to vibration during service.
In addition, the heat pipes themselves are charged with a working fluid which, ur ambient conditions, is at a vacuum with respect to atmospheric pressure. Thus, any atteml vent non-condensible gases by merely "cracking" open a union 30 such as shown in Fig.
ambient conditions, would not exhaust gas from the heat pipe, but would rather intake amb air. For most practical applications, it is thus required to increase the temperature of the pipes to a point above 240°F so that the pressure within the heat pipe is above atmosph pressure. "Cracking" of the union 30 would thus permit venting of the higher pressure r condensible gases from the heat pipe to the atmosphere. However, while heating an indivic heat pipe might be a relatively straightforward task, these heat pipes are typically part of a la air heater system wherein such individualized heating is not possible. The entire air heater it must be elevated in temperature by the use of space heaters and obtaining access for loca same is often extremely dii~cult. Further, the heat pipes themselves might contain a flamm:
gas, such as hydrogen, and manually venting same could present a hazard.
Grover (LJ.S. Patent No. 4,020,898) and Hoke, Jr. (U.S. Patent No. 4,799,537) disc heat pipe apparatus having conventional crimped, soldered or welded end fittings.
Murphy et al. (U.S. Patent Nos. 4,881,580 and 4,776,389) disclose methods apparatus for evacuating and filling heat pipes in similar closed vessels. As disclosed in the ' Murphy et al patent, the heat pipe 16 is processed on a table 14 being held at one end by gu 18, 20 and a clamp 24 having thrust bar 26 and thrust finger 28. A block 22 is provided wi process tube 54 at a hex shank 68 which moves the piston 60 having O-ring 64, 66. Inte~al the heat pipe 16 is a threaded valve 40 having an axial bore 44 and cross bores 46. The pro tube 54 is to provide a vacuum and for filling of the working fluid into the heat pipe 16. Tun the hex shank 68 unscrews the valve 40 from the heat pipe 16 and allows an open passage to process tube 54. O-rings on the piston 60 seal the apparatus from the atmosphere.
Mahdjuri-Sabet (LJ.S. Patent No. 5,241,950) discloses, in essence, safety means for a pipe so that damage to the heat pipe due to excessive condenser temperatures is avoi Referring to Figs. 1 and 2 thereof, the heat pipe 1 is provided with a transparent jacket that h the working fluid and the evaporator, and is interconnected by a conduit 4 to the condens~
Located within an expanded portion of the condenser 2 is an annular plug 13 encirclin;
ambient conditions, would not exhaust gas from the heat pipe, but would rather intake amb air. For most practical applications, it is thus required to increase the temperature of the pipes to a point above 240°F so that the pressure within the heat pipe is above atmosph pressure. "Cracking" of the union 30 would thus permit venting of the higher pressure r condensible gases from the heat pipe to the atmosphere. However, while heating an indivic heat pipe might be a relatively straightforward task, these heat pipes are typically part of a la air heater system wherein such individualized heating is not possible. The entire air heater it must be elevated in temperature by the use of space heaters and obtaining access for loca same is often extremely dii~cult. Further, the heat pipes themselves might contain a flamm:
gas, such as hydrogen, and manually venting same could present a hazard.
Grover (LJ.S. Patent No. 4,020,898) and Hoke, Jr. (U.S. Patent No. 4,799,537) disc heat pipe apparatus having conventional crimped, soldered or welded end fittings.
Murphy et al. (U.S. Patent Nos. 4,881,580 and 4,776,389) disclose methods apparatus for evacuating and filling heat pipes in similar closed vessels. As disclosed in the ' Murphy et al patent, the heat pipe 16 is processed on a table 14 being held at one end by gu 18, 20 and a clamp 24 having thrust bar 26 and thrust finger 28. A block 22 is provided wi process tube 54 at a hex shank 68 which moves the piston 60 having O-ring 64, 66. Inte~al the heat pipe 16 is a threaded valve 40 having an axial bore 44 and cross bores 46. The pro tube 54 is to provide a vacuum and for filling of the working fluid into the heat pipe 16. Tun the hex shank 68 unscrews the valve 40 from the heat pipe 16 and allows an open passage to process tube 54. O-rings on the piston 60 seal the apparatus from the atmosphere.
Mahdjuri-Sabet (LJ.S. Patent No. 5,241,950) discloses, in essence, safety means for a pipe so that damage to the heat pipe due to excessive condenser temperatures is avoi Referring to Figs. 1 and 2 thereof, the heat pipe 1 is provided with a transparent jacket that h the working fluid and the evaporator, and is interconnected by a conduit 4 to the condens~
Located within an expanded portion of the condenser 2 is an annular plug 13 encirclin;
overflow tube 10 which creates a fluid reservoir 12 therebetween. Helical springs 14 and maintain axial forces on the annular plug, but allow it to move when rising working fluid f the condenser 2 during heat absorption.
Stockman (U.S. Patent No. 4,341,000) discloses a method of charging a heat p whereby a predetermined amount of fluid may be charged into the heat pipe includes a metl of changing fluids as necessary. The heat pipe 12 as provided at its upper end a T-fitting through which is provided an inlet working fluid and which also provides for air exhaust.
coupling 26 is used to removably connect the T-fitting 24 to the heat pipe 12.
Provided in internal portion of the heat pipe 12 is a vertical stand pipe 38 whose height is predetermined that a suction pump 32 connected at a lower end thereof will only be able to remove that port of liquid above the end termination of the stand pipe 38. The height of the stand pipe 38 can varied as necessary to provide a predetermined level of liquid in the heat pipe 12.
Hartle et al. (LJ.S. Patent No. 5,226,580) is of interest as disclosing an automated h pipe processing system, wherein a heat pipe casing and an end cap is formed into a heat pi then cleaned by means of glow-discharge plasma, filled with a working fluid, and fixing the c cap on the heat pipe by inertia welding.
Franco et al. (LJ.S. Patent No. 4,586,561 ) discloses a low temperature heat p employing a hydrogen getter. The term "low temperature" as used in Franco et al. mean temperature below 0°C (32°F)at which the heat pipe is operational. The patent discusses one the largest uses of heat pipes at present being the permafrost stabilization of the trans-Alasl pipeline. The heat pipes under these conditions are contained in vertical support members t are designed to operate in colder months when the permafrost temperature at moderate deF
(20 ft.) is above the air temperature. Heat pipes using ammonia as the heat transport medi have been installed using two heat pipes for each vertical support member.
During the wig months when the air temperature is below the ground temperature, the heat pipe function:
remove heat from the permafrost thus maintaining its integrity during the subsequent sump months when thawing can potentially occur. A problem with the operation of the heat pipe the presence of small amounts of non-condensible hydrogen gas which can collect, for exam by a corrosion reaction between water, which may be an impurity in the ammonia and the car -S-steel of the pipe. The hydrogen gas accumulates primarily in the condenser section and inhi the ammonia vapor from condensing at the top of the condensation section. This result "condenser blockage" and leads to reduced heat removal capability. Thus, the patent is direr to a means or method of removal of such contaminant hydrogen to allow the heat pip continue to operate and continue to prevent the permafrost from degrading.
Accordingly, patent discloses a hydrogen getter material, preferably being a zirconium intermetallic al which is effective even in the presence of air and/or water. More specifically, Franco a discloses a hydrogen getter assembly for removing contaminant hydrogen gas from an ammc heat pipe which assembly can be mounted on the pipe «n top or on the side, or located inside pipe on the condensation wall or section. As shown in Fig. 2 of Franco et al., a heat pipe inserted into the permafrost ground 11 has a hydrogen gas getter assembly 23 mounted vertic on top being inserted through cover plate 31. The getter assembly 23 has located therein a ge material 24 contained in getter canister 25 and held in place by retaining element 26 whic sufficiently porous to allow gaseous NH3 and HZ through to contact the getter material. Fi of Franco et al. shows another embodiment of the heat pipe having a getter assembly 23 moot on the side of the heat pipe 17 rather than on the top. This embodiment is said to provide ea installation of the getter assembly to the heat pipe since it avoids a double-seal penetra~
process as generally practiced for the assembly of the heat pipe illustrated in Fig. 2 thereof. ' getter assembly can be attached to the assembled and charged heat pipe (which chargin generally performed under vacuum to avoid the entry of moisture and/or air) by conventienal tapping methods or non-welding penetration methods: Fig. 4 shows a preferred embodimer the hydrogen getter assembly 23, wherein the canister housing 25 is inserted in the heat pipe 17. Hydrogen and ammonia enter into the interior of the canister 25 by means of communication inlet 27 and the resulting initial pressure is sufficient to break the rupture 29. The getter material is retained in position by retaining element 26 which is porous permeable to hydrogen and ammonia but is inert and has sufficient strength to provide a bay to the movement of the getter material into the heat pipe itself. In addition, it is stated that tl may also be present a valve (not shown) positioned between the canister 25 and exte condensation wall and operating with the communication inlet 27. The valve 28 is said t~
designed to prevent external leakage of ammonia at low temperatures and use of the vale optional in preparing the heat pipe by non-welding penetration but is preferred when utiliz for example, hot tapping methods. In addition to the valve in the communication inlet 27, stated that there can optimally be joints formed by fittings, such as quick-connects, which al for closing and detaching the canister after use and protecting the canister contents from air, the heat tube atmosphere from escaping, during the detachment step.
While Franco et al. discloses that hydrogen getter assemblies can be removably coul to heat pipes via quick-connects, he neither teaches nor suggests use of such an assembly dw the filling, sealing or field servicing of such heat pipes. As indicated earlier, various servic operations may have to be performed on heat pipes once they have been installed in the fi These include the tasks of measuring the internal heat pipe pressure to determine how m non-condensible gas is present; obtaining samples of such non-condensible gases for analy venting non-condensible gases from the heat pipe; obtaining a sample of the working fluid fi the heat pipe for analysis; and performing internal visual inspections of the heat pipe.
Franco et al. is also not particularly concerned with the manufacturing process for 1 pipes. Many heat pipes are designed to have spirally wound aluminum fins present on both evaporator and condenser sections. During the finning process, the heat pipe is spun at a r speed of rotation. Imbalances cannot be tolerated during such finning processes. Further, addition of fins to heat pipes, particularly carbon steel fins, add significant weight to the 1 pipe and therefore it is not practical from a manufacturing standpoint to fill and seal the heat 1 after it has been finned. Additionally, since heat pipes require a specified internal surf cleanliness, finning the heat pipes prior to the welding of the end cap and the like increases chance of not meeting this requirement due to flash rust concerns. Further, if it is determi that the heat pipes do require cleaning, it would certainly be easier to do this without the being present. Finally, the fins on some portions of heat pipes, particularly the condenser of the heat pipes, may use aluminum fins which are a much softer material then carbon s~
Such fins would most certainly be damaged beyond repair if manufacture of the heat pipe v completed after the fins were attached to the tube itself.
_7_ It is thus clear that an improved method and apparatus for filling, sealing and f servicing individual heat pipes is desirable.
SUMMARY OF THE INVENTION
The present invention provides a solution to these problems by using a high temperat high pressure disconnecting valve means in place of a union for use during and after manufac.
of the heat pipe. During manufacture of a heat pipe, one end of the fill tube is welded to the cap and the opposite end of the fill tube is connected to a compression fitting of disconnecting valve means. From this point, the heat pipe can then be filled with the work fluid, degassed and evacuated to a "hard" vacuum. The disconnecting valve means is fitted c a protective plug to permit the disconnecting valve means to operate at a higher opera temperature and pressure than would otherwise be possible if only the disconnecting valve me were provided at the end of the fill tube. The protective plug also prevents dirt from damak the internal mechanism of the disconnecting valve during operation.
The use of the disconnecting valve means in combination with the fill tube thus prov:
easier access to the inside of the heat pipe, and simplifies the current manufacturing pro<
while improving the quality and reliability of the heat pipe product. In the present invention, disconnecting valve means itself can be a type of quick-connect which operates in an analog fashion to quick-disconnect fittings or, couplings provided on common air hose lines. One-of the disconnecting valve remains on the heat pipe; the other half would be "clipped" o~
needed during manufacture, or in the field, connected to a hose and suitable equipment (tat vacuum pumps etc.) to allow filling, venting, or servicing.
Accordingly, one aspect of the present invention is drawn to a spirally-finned heat I
apparatus which has a longitudinal axis of symmetry, employs a water-based working fluid, which operates with an internal pressure/temperature range from approximately aml;
temperature and pressure, up to approximately 100 psig and 400°F, and which can be repeat.
and easily serviced in the field. The spirally-finned heat pipe apparatus comprises a cylind~
heat pipe tube having end caps welded thereto. The heat pipe apparatus also comprises a fill welded and fluidically connected at a first end thereof to one end cep, the fill tube havi:
_g_ longitudinal axis of symmetry coaxial with the heat pipe apparatus longitudinal axis symmetry. The heat pipe further comprises a disconnecting valve means fluidically connec to a second end of the fill tube, for providing repeatable access to and resealing of an inter portion of the heat pipe, the disconnecting valve means also having a longitudinal axis symmetry coaxial with the heat pipe apparatus longitudinal axis of symmetry and an outs diameter not greater than 0.95 of an outside diameter of the cylindrical heat pipe tube to per installation of the heat pipe apparatus through an aperture in a tube sheet.
Another aspect of the present invention is drawn to a method of manufacturing a fic serviceable, spirally-finned, cylindrical heat pipe apparatus which has a longitudinal axi:
symmetry. The method 'comprises several steps. ):;nd caps are welded to each end a cylindrical heat pipe tube. A first end of a fill tube is welded to one of the end caps to prov a fluidic passage therethrough which provides access into an internal portion of the cylindri heat pipe tube. Disconnecting valve means are fluidically connected to a second end of the tube so as to provide easy and repeatable access to and resealing of an internal portion of cylindrical heat pipe tube. The cylindrical heat pipe tube is.evacuated and filled using disconnecting valve means. The method finally comprises the step of spinning the cylindr heat pipe tube about its longitudinal axis of symmetry and applying the spiral fins thereto as cylindrical heat pipe tube spins.
Yet another aspect of the present invention is drawn to a method of field-servicing a 1 pipe apparatus having disconnecting valve means provided on a fill tube fluidically connec to an end cap thereof, the disconnecting valve means having a first end removably and fluidic.
connected to the fill tube and a second end provided with a removable protective plug. '' protective plug is removed from the second end of the disconnecting valve means to prop access to an internal portion of the heat pipe apparatus. A stem portion is then coupled to second end of the disconnecting valve means, to provide a fluidic passage through the fill t , , into the internal portion of the heat pipe apparatus.
The various features of novelty which characterize the invention are pointed out ~
particularity in the claims annexed to and forming a part of this disclosure.
For a be understanding of the invention, its operating advantages and the specific benefits attained b:
uses, reference is made to the accompanying drawings and descriptive matter in which prefer embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
Fig. 1 represents one prior art heat pipe fill tube construction;
Fig. 2 represents another prior art heat pipe fill tube construction employ primary and secondary fill tubes and a union therebetween;
Fig. 3 represents the improved heat pipe construction employing the f serviceable fill tube of the present invention and having a protective F
inserted in a rear portion of the disconnecting valve;
Fig. 3A represents the improved heat pipe construction with a hose and fir inserted in the rear portion of the disconnecting valve to allow fill-venting, or servicing;
Fig. 4 is a schematic representation of the degassing/evacuation step used in manufacturing process for heat pipes using the invention;
Fig. 5 is a schematic representation of equipment that would be used to f service a heat pipe made and used according to the invention; and Figs. 6A-6D are several schematic representations of different field servicing operati that are possible through use of the invention. --DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings generally, wherein like numerals designate the sam~
functionally similar parts, and to Fig. 3 in particular, there is shown one embodiment of present invention. The heat pipe 10 has a longitudinal axis of symmetry 11 and a hemisphe~
or elliptical end cap 14. One end of a fill tube 52 having a longitudinal axis of symmetry coa with that of the heat pipe 10 is welded to hemispherical or elliptical end cap 14 by means of ~
16. According to the invention, the other end of the f ill tube 52 is connected to disconnec valve means generally designated 50. The heat pipe 10, fill tube 52, and disconnecting v means SO are fluidically interconnected so as to facilitate filling, sealing and evacuation of heat pipe 10 via the disconnecting valve means 50 both during manufacture and subsequei in the field. Disconnecting valve means SO advantageously comprises a quick-connect typc disconnecting valve such as a Swagelok~ quick-connect (who also manufactures the prior S unions of Fig. 2). (Swagelok~ is a registered trademark of the Swagelok Quick-Connect Hudson, Ohio.) The disconnecting valve means SO also has a longitudinal axis of symme coaxial with that of the heat pipe apparatus longitudinal axis of symmetry 11 and an outs diameter D, preferably not greater than 0.95 of an outside diameter D of the cylindrical heat F
tube to permit installation of the heat pipe apparatus through an aperture in a tube sheet <
10 heat pipe air heater (not shown). In any event, the outside diameter D, of the disconnect valve means 50 must be less than the outside diameter D of the cylindrical heat pipe 10 so t the disconnecting valve means 50 can be easily inserted through the aperatures in the tube she during construction.
As shown in Fig. 3, the disconnecting valve means has a front portion 53 tha connected to the fill tube 52 by means of a compression fitting contained therein comprising same design conical bushing 40 and threaded portion 38 shown in Fig. 2.
Disconnecting va means 50 is also provided with a removably coupled protective plug 54 to permit it and associated heat pipe 10 and fill tube 52 to operate at a higher operating temperature and press than would otherwise be possible. Protective plug 54 is.secured to disconnecting valve me 50 by internal locking mechanism 55, and also prevents dirt from accumulating in disconnect valve means S0. Removing protective plug 54 from disconnecting valve means 50 permit:
body valve O-ring 56 to seal heat pipe 10 and fill tube 52.
Referring to Fig. 3A, a stem portion 57 of the disconnecting valve means 50 is remove and sealably engagable with the front portion 53 to effect any filling, sealing and servicinf the heat pipe 10, both during manufacture and afterwards in the field.
Flexible hose S
fluidically connected to the stem portion 57 by means of another compression fitting 59. Dw manufacture the heat pipe 10 can be filled with the working fluid, degassed and evacuated "hard" vacuum through flexible hose 58.
-lI-A Double End Shut-Off (DESO) O-ring 60 seals stem portion 57 and flexible host when stem portion 57 is disconnected from disconnecting valve means 50. DESO O-rin~
enables the pressure in flexible hose 58 to be maintained when stem portion 57 is disconnec from one heat pipe 10 and connected to another heat pipe 10. The combination of elements 58, 59, and 60 will be generally referred to as coupling 72, or as being removably coupled at in the following portions of this description.
Heat pipe 10 can thus be serviced in the field without the requirement of heating the 1 pipe 10 to 240°F for venting non-condensible gases.
The use of the disconnecting valve means 50 in combination with the fill tube 52 t provides easier access to the inside of the heat pipe 10, and simplifies the current manufactw process while improving the quality and reliability of the 'heat pipe product.
In the pre;
invention, the disconnecting valve means 50 itself can be a type of quick-connect which open.
in an analogous fashion to quick-disconnect fittings or couplings provided on common air h lines. One-half of the disconnecting valve means SO remains on the heat pipe 10; the other l would be "clipped" on as needed during manufacture, or in the field, connected to a hose suitable equipment (tanks, vacuum pumps etc.) to allow, filling, venting, or servicing.
Swagelok~-type quick-connects are known which can be adapted for use in tempera and pressure ratings of 100 psig and 400°F. Further development of the seal materials, nary the O-rings, to meet the service pressure and temperature requirements above this range wil necessary for other heat pipe applications.
Preferably the invention employs "off the shelf' Swagelok~ type quick-connects on heat pipes 10, as limited by the cited temperature and pressure ranges. For example, Swagek instrumentation brochure No. QC-590-1, April 1993, discloses one example of the panic type of couplings which cari be adapted to this heat pipe 10 application that have pressure rat up to 3,000 psig, but at 70°F. Similarly, temperature ratings with various types of O-rings ext the range of these devices up to the 400°F range, but only at 100 psig.
The selection of particular type of disconnecting valve means 50 and their materials of construction wil determined by the temperature and pressure under which the heat pipe 10 is expected to open A plurality of heat pipes 10 using the present invention would be employed in the "c end" portion of a gas to air heat transfer device; i.e., a heat pipe air heater (not shown). ' "cold end" portion of such an air heater is that location wherein the cooled gas exits from the heater, and the cold inlet air enters. Similarly, the "hot end" of such an air heater is that locat wherein the hot gas enters and the heated air exits. The present invention would generally be applied to the "hot end" portions of the air heater because of the heat pipe 10 operat temperature and pressure. Sometimes hydrogen or other noncondensible gases are producec the heat pipes 10. On the "hot end" portion of the air heater, any hydrogen gas produced is un a sufficient pressure that will cause it to be compressed and only disable a small portion of heat pipe itself. At these elevated pressures, the hydrogen gas is actually driven out through walls of the heat pipe 10; and thus only causes the loss of a small portion of the effective len of the heat pipe 10. In contrast, heat pipes operating on the "cold end" of the air heater are operating at such a high pressure that would cause the hydrogen gas to be either compressed o at a localized end of the heat pipe 10, or to be driven through the walls.
Therefore, a lar portion of the length of the heat pipe 10 is disabled when an amount of hydrogen accumulates. These are the heat pipes 10 which are particularly suited for application of present invention, since the heat pipe at the "cold end" of the air heater may be operating o into the approximately 320°F range, wherein the saturation pressure at this temperature is 8 psia.
Referring to Fig. 4 there is shown a schematic representation of the degassing/evacuat step used in the manufacturing process for heat pipes using the present invention. One enc the heat pipe 10 and its associated disconnecting valve means 50 is partially immersed in a de tank 61 to which heat is applied as shown to increase the temperature of the contents of the 1 pipe 10. Water is provided from a source 62 via line 64 through a volume measuring mean:
of known construction. A valve 68 and a line 70 are provided and removably coupled at 7:
disconnecting valve means 50. A vacuum pump 74, capable of producing vacuums as lov approximately -30" Hg, is connected via line 76 to a tee connection 78 so as to draw a vacs:
on the heat pipe 10. Once the filling and degassing of heat pipe 10 is complete, the vacs providing equipment and water providing equipment would be decoupled from the disconnec~
valve means 50. The heat pipe 10 would then be available for ftufiher processing. The heat 1 itself has an outside diameter ranging from approximately 1'/. inches to approximate) inches, and the spiral fins applied to the outside surface thereof would have an outside diam ranging from approximately 2'/e inches to approximately 3'/z inches. Since the outside diam 5 D, of the preferred disconnecting valve means is approximately 1 inch, the resulting combina~
achieves the desired difference in diameters between that of the disconnecting valve mean:
and the heat pipe 10.
Fig. 5 shows a schematic representation of equipment that would be used to field ser a heat pipe made and used according to the present invention. Fig. 5 shows a single heat F
10 10 with its associated fill tube 52 and disconnecting valve means 50. A
portable field servic apparatus 80, and a vacuum pump 74 having the same vacuum producing abilities as descri earlier, would be provided to perform certain field servicing operations as described earl Apparatus 80 is connected to the heat pipe 10 via a flexible line or hose 82 of desired length, removably coupled thereto at 72. Apparatus 80 would advantageously comprise an arrangers of valves 84, 86, and 88 to permit fluidic communication between the heat pipe 10 (via line and the vacuum pump 74, a gas sample container 90, and a pressure gage 92 as shown. O
the field servicing operations are complete, the portable field servicing apparatus 80 woulc disconnected from the disconnecting valve means 50.
Figs. 6A-6D illustrate several other field servicing operations that are possible thro use of the present invention. Fig. 6A shows the heat pipe 10 before servicing.
Figs. 6B and show how samples of working fluid 18 or visual inspections of the internal portion of the 1 pipe 10 would be performed. For these field servicing operations, the protective plug 54 and disconnecting valve means 50 would be removed to allow an open passageway through the tube 52 into the heat pipe 10. The compression fitting S3 allows this to be accomplished. A
94 and fluid pump means 96 would be used to obtain a. sample of the fluid 18 contained wi the heat pipe 10 and provide it to a liquid sample container 98 via line 100.
A long, sle~
probe or sample line 102 would be extended down into the heat pipe 10 for this purpose shown in Fig. 6B. Alternatively, as shown in Fig. 6C, a visual inspection of the interior por of the heat pipe 10 could be facilitated by means of a known fiberoptic borescope operatively connected via line 106 to video and light providing equipment 108 connected via 110 to a video monitor 112 in known fashion. At the conclusion of such inspections an<
samplings, the disconnecting valve means SO and protective plug 54 would be reattached, a the heat pipe 10 had been restored to its working condition, as shown in Fig.
6D.
While specific embodiments of the invention have been shown and described in de to illustrate the application of the principles of the invention, those skilled in the art appreciate that changes may be made in the form of the invention covered by the follov~
claims without departing from such principles. In some embodiments of the invention, cer features of the invention may sometimes be used to advantage without a corresponding us~
the other features. Accordingly, all such changes and embodiments properly fall within scope of the following claims.
Stockman (U.S. Patent No. 4,341,000) discloses a method of charging a heat p whereby a predetermined amount of fluid may be charged into the heat pipe includes a metl of changing fluids as necessary. The heat pipe 12 as provided at its upper end a T-fitting through which is provided an inlet working fluid and which also provides for air exhaust.
coupling 26 is used to removably connect the T-fitting 24 to the heat pipe 12.
Provided in internal portion of the heat pipe 12 is a vertical stand pipe 38 whose height is predetermined that a suction pump 32 connected at a lower end thereof will only be able to remove that port of liquid above the end termination of the stand pipe 38. The height of the stand pipe 38 can varied as necessary to provide a predetermined level of liquid in the heat pipe 12.
Hartle et al. (LJ.S. Patent No. 5,226,580) is of interest as disclosing an automated h pipe processing system, wherein a heat pipe casing and an end cap is formed into a heat pi then cleaned by means of glow-discharge plasma, filled with a working fluid, and fixing the c cap on the heat pipe by inertia welding.
Franco et al. (LJ.S. Patent No. 4,586,561 ) discloses a low temperature heat p employing a hydrogen getter. The term "low temperature" as used in Franco et al. mean temperature below 0°C (32°F)at which the heat pipe is operational. The patent discusses one the largest uses of heat pipes at present being the permafrost stabilization of the trans-Alasl pipeline. The heat pipes under these conditions are contained in vertical support members t are designed to operate in colder months when the permafrost temperature at moderate deF
(20 ft.) is above the air temperature. Heat pipes using ammonia as the heat transport medi have been installed using two heat pipes for each vertical support member.
During the wig months when the air temperature is below the ground temperature, the heat pipe function:
remove heat from the permafrost thus maintaining its integrity during the subsequent sump months when thawing can potentially occur. A problem with the operation of the heat pipe the presence of small amounts of non-condensible hydrogen gas which can collect, for exam by a corrosion reaction between water, which may be an impurity in the ammonia and the car -S-steel of the pipe. The hydrogen gas accumulates primarily in the condenser section and inhi the ammonia vapor from condensing at the top of the condensation section. This result "condenser blockage" and leads to reduced heat removal capability. Thus, the patent is direr to a means or method of removal of such contaminant hydrogen to allow the heat pip continue to operate and continue to prevent the permafrost from degrading.
Accordingly, patent discloses a hydrogen getter material, preferably being a zirconium intermetallic al which is effective even in the presence of air and/or water. More specifically, Franco a discloses a hydrogen getter assembly for removing contaminant hydrogen gas from an ammc heat pipe which assembly can be mounted on the pipe «n top or on the side, or located inside pipe on the condensation wall or section. As shown in Fig. 2 of Franco et al., a heat pipe inserted into the permafrost ground 11 has a hydrogen gas getter assembly 23 mounted vertic on top being inserted through cover plate 31. The getter assembly 23 has located therein a ge material 24 contained in getter canister 25 and held in place by retaining element 26 whic sufficiently porous to allow gaseous NH3 and HZ through to contact the getter material. Fi of Franco et al. shows another embodiment of the heat pipe having a getter assembly 23 moot on the side of the heat pipe 17 rather than on the top. This embodiment is said to provide ea installation of the getter assembly to the heat pipe since it avoids a double-seal penetra~
process as generally practiced for the assembly of the heat pipe illustrated in Fig. 2 thereof. ' getter assembly can be attached to the assembled and charged heat pipe (which chargin generally performed under vacuum to avoid the entry of moisture and/or air) by conventienal tapping methods or non-welding penetration methods: Fig. 4 shows a preferred embodimer the hydrogen getter assembly 23, wherein the canister housing 25 is inserted in the heat pipe 17. Hydrogen and ammonia enter into the interior of the canister 25 by means of communication inlet 27 and the resulting initial pressure is sufficient to break the rupture 29. The getter material is retained in position by retaining element 26 which is porous permeable to hydrogen and ammonia but is inert and has sufficient strength to provide a bay to the movement of the getter material into the heat pipe itself. In addition, it is stated that tl may also be present a valve (not shown) positioned between the canister 25 and exte condensation wall and operating with the communication inlet 27. The valve 28 is said t~
designed to prevent external leakage of ammonia at low temperatures and use of the vale optional in preparing the heat pipe by non-welding penetration but is preferred when utiliz for example, hot tapping methods. In addition to the valve in the communication inlet 27, stated that there can optimally be joints formed by fittings, such as quick-connects, which al for closing and detaching the canister after use and protecting the canister contents from air, the heat tube atmosphere from escaping, during the detachment step.
While Franco et al. discloses that hydrogen getter assemblies can be removably coul to heat pipes via quick-connects, he neither teaches nor suggests use of such an assembly dw the filling, sealing or field servicing of such heat pipes. As indicated earlier, various servic operations may have to be performed on heat pipes once they have been installed in the fi These include the tasks of measuring the internal heat pipe pressure to determine how m non-condensible gas is present; obtaining samples of such non-condensible gases for analy venting non-condensible gases from the heat pipe; obtaining a sample of the working fluid fi the heat pipe for analysis; and performing internal visual inspections of the heat pipe.
Franco et al. is also not particularly concerned with the manufacturing process for 1 pipes. Many heat pipes are designed to have spirally wound aluminum fins present on both evaporator and condenser sections. During the finning process, the heat pipe is spun at a r speed of rotation. Imbalances cannot be tolerated during such finning processes. Further, addition of fins to heat pipes, particularly carbon steel fins, add significant weight to the 1 pipe and therefore it is not practical from a manufacturing standpoint to fill and seal the heat 1 after it has been finned. Additionally, since heat pipes require a specified internal surf cleanliness, finning the heat pipes prior to the welding of the end cap and the like increases chance of not meeting this requirement due to flash rust concerns. Further, if it is determi that the heat pipes do require cleaning, it would certainly be easier to do this without the being present. Finally, the fins on some portions of heat pipes, particularly the condenser of the heat pipes, may use aluminum fins which are a much softer material then carbon s~
Such fins would most certainly be damaged beyond repair if manufacture of the heat pipe v completed after the fins were attached to the tube itself.
_7_ It is thus clear that an improved method and apparatus for filling, sealing and f servicing individual heat pipes is desirable.
SUMMARY OF THE INVENTION
The present invention provides a solution to these problems by using a high temperat high pressure disconnecting valve means in place of a union for use during and after manufac.
of the heat pipe. During manufacture of a heat pipe, one end of the fill tube is welded to the cap and the opposite end of the fill tube is connected to a compression fitting of disconnecting valve means. From this point, the heat pipe can then be filled with the work fluid, degassed and evacuated to a "hard" vacuum. The disconnecting valve means is fitted c a protective plug to permit the disconnecting valve means to operate at a higher opera temperature and pressure than would otherwise be possible if only the disconnecting valve me were provided at the end of the fill tube. The protective plug also prevents dirt from damak the internal mechanism of the disconnecting valve during operation.
The use of the disconnecting valve means in combination with the fill tube thus prov:
easier access to the inside of the heat pipe, and simplifies the current manufacturing pro<
while improving the quality and reliability of the heat pipe product. In the present invention, disconnecting valve means itself can be a type of quick-connect which operates in an analog fashion to quick-disconnect fittings or, couplings provided on common air hose lines. One-of the disconnecting valve remains on the heat pipe; the other half would be "clipped" o~
needed during manufacture, or in the field, connected to a hose and suitable equipment (tat vacuum pumps etc.) to allow filling, venting, or servicing.
Accordingly, one aspect of the present invention is drawn to a spirally-finned heat I
apparatus which has a longitudinal axis of symmetry, employs a water-based working fluid, which operates with an internal pressure/temperature range from approximately aml;
temperature and pressure, up to approximately 100 psig and 400°F, and which can be repeat.
and easily serviced in the field. The spirally-finned heat pipe apparatus comprises a cylind~
heat pipe tube having end caps welded thereto. The heat pipe apparatus also comprises a fill welded and fluidically connected at a first end thereof to one end cep, the fill tube havi:
_g_ longitudinal axis of symmetry coaxial with the heat pipe apparatus longitudinal axis symmetry. The heat pipe further comprises a disconnecting valve means fluidically connec to a second end of the fill tube, for providing repeatable access to and resealing of an inter portion of the heat pipe, the disconnecting valve means also having a longitudinal axis symmetry coaxial with the heat pipe apparatus longitudinal axis of symmetry and an outs diameter not greater than 0.95 of an outside diameter of the cylindrical heat pipe tube to per installation of the heat pipe apparatus through an aperture in a tube sheet.
Another aspect of the present invention is drawn to a method of manufacturing a fic serviceable, spirally-finned, cylindrical heat pipe apparatus which has a longitudinal axi:
symmetry. The method 'comprises several steps. ):;nd caps are welded to each end a cylindrical heat pipe tube. A first end of a fill tube is welded to one of the end caps to prov a fluidic passage therethrough which provides access into an internal portion of the cylindri heat pipe tube. Disconnecting valve means are fluidically connected to a second end of the tube so as to provide easy and repeatable access to and resealing of an internal portion of cylindrical heat pipe tube. The cylindrical heat pipe tube is.evacuated and filled using disconnecting valve means. The method finally comprises the step of spinning the cylindr heat pipe tube about its longitudinal axis of symmetry and applying the spiral fins thereto as cylindrical heat pipe tube spins.
Yet another aspect of the present invention is drawn to a method of field-servicing a 1 pipe apparatus having disconnecting valve means provided on a fill tube fluidically connec to an end cap thereof, the disconnecting valve means having a first end removably and fluidic.
connected to the fill tube and a second end provided with a removable protective plug. '' protective plug is removed from the second end of the disconnecting valve means to prop access to an internal portion of the heat pipe apparatus. A stem portion is then coupled to second end of the disconnecting valve means, to provide a fluidic passage through the fill t , , into the internal portion of the heat pipe apparatus.
The various features of novelty which characterize the invention are pointed out ~
particularity in the claims annexed to and forming a part of this disclosure.
For a be understanding of the invention, its operating advantages and the specific benefits attained b:
uses, reference is made to the accompanying drawings and descriptive matter in which prefer embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
Fig. 1 represents one prior art heat pipe fill tube construction;
Fig. 2 represents another prior art heat pipe fill tube construction employ primary and secondary fill tubes and a union therebetween;
Fig. 3 represents the improved heat pipe construction employing the f serviceable fill tube of the present invention and having a protective F
inserted in a rear portion of the disconnecting valve;
Fig. 3A represents the improved heat pipe construction with a hose and fir inserted in the rear portion of the disconnecting valve to allow fill-venting, or servicing;
Fig. 4 is a schematic representation of the degassing/evacuation step used in manufacturing process for heat pipes using the invention;
Fig. 5 is a schematic representation of equipment that would be used to f service a heat pipe made and used according to the invention; and Figs. 6A-6D are several schematic representations of different field servicing operati that are possible through use of the invention. --DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings generally, wherein like numerals designate the sam~
functionally similar parts, and to Fig. 3 in particular, there is shown one embodiment of present invention. The heat pipe 10 has a longitudinal axis of symmetry 11 and a hemisphe~
or elliptical end cap 14. One end of a fill tube 52 having a longitudinal axis of symmetry coa with that of the heat pipe 10 is welded to hemispherical or elliptical end cap 14 by means of ~
16. According to the invention, the other end of the f ill tube 52 is connected to disconnec valve means generally designated 50. The heat pipe 10, fill tube 52, and disconnecting v means SO are fluidically interconnected so as to facilitate filling, sealing and evacuation of heat pipe 10 via the disconnecting valve means 50 both during manufacture and subsequei in the field. Disconnecting valve means SO advantageously comprises a quick-connect typc disconnecting valve such as a Swagelok~ quick-connect (who also manufactures the prior S unions of Fig. 2). (Swagelok~ is a registered trademark of the Swagelok Quick-Connect Hudson, Ohio.) The disconnecting valve means SO also has a longitudinal axis of symme coaxial with that of the heat pipe apparatus longitudinal axis of symmetry 11 and an outs diameter D, preferably not greater than 0.95 of an outside diameter D of the cylindrical heat F
tube to permit installation of the heat pipe apparatus through an aperture in a tube sheet <
10 heat pipe air heater (not shown). In any event, the outside diameter D, of the disconnect valve means 50 must be less than the outside diameter D of the cylindrical heat pipe 10 so t the disconnecting valve means 50 can be easily inserted through the aperatures in the tube she during construction.
As shown in Fig. 3, the disconnecting valve means has a front portion 53 tha connected to the fill tube 52 by means of a compression fitting contained therein comprising same design conical bushing 40 and threaded portion 38 shown in Fig. 2.
Disconnecting va means 50 is also provided with a removably coupled protective plug 54 to permit it and associated heat pipe 10 and fill tube 52 to operate at a higher operating temperature and press than would otherwise be possible. Protective plug 54 is.secured to disconnecting valve me 50 by internal locking mechanism 55, and also prevents dirt from accumulating in disconnect valve means S0. Removing protective plug 54 from disconnecting valve means 50 permit:
body valve O-ring 56 to seal heat pipe 10 and fill tube 52.
Referring to Fig. 3A, a stem portion 57 of the disconnecting valve means 50 is remove and sealably engagable with the front portion 53 to effect any filling, sealing and servicinf the heat pipe 10, both during manufacture and afterwards in the field.
Flexible hose S
fluidically connected to the stem portion 57 by means of another compression fitting 59. Dw manufacture the heat pipe 10 can be filled with the working fluid, degassed and evacuated "hard" vacuum through flexible hose 58.
-lI-A Double End Shut-Off (DESO) O-ring 60 seals stem portion 57 and flexible host when stem portion 57 is disconnected from disconnecting valve means 50. DESO O-rin~
enables the pressure in flexible hose 58 to be maintained when stem portion 57 is disconnec from one heat pipe 10 and connected to another heat pipe 10. The combination of elements 58, 59, and 60 will be generally referred to as coupling 72, or as being removably coupled at in the following portions of this description.
Heat pipe 10 can thus be serviced in the field without the requirement of heating the 1 pipe 10 to 240°F for venting non-condensible gases.
The use of the disconnecting valve means 50 in combination with the fill tube 52 t provides easier access to the inside of the heat pipe 10, and simplifies the current manufactw process while improving the quality and reliability of the 'heat pipe product.
In the pre;
invention, the disconnecting valve means 50 itself can be a type of quick-connect which open.
in an analogous fashion to quick-disconnect fittings or couplings provided on common air h lines. One-half of the disconnecting valve means SO remains on the heat pipe 10; the other l would be "clipped" on as needed during manufacture, or in the field, connected to a hose suitable equipment (tanks, vacuum pumps etc.) to allow, filling, venting, or servicing.
Swagelok~-type quick-connects are known which can be adapted for use in tempera and pressure ratings of 100 psig and 400°F. Further development of the seal materials, nary the O-rings, to meet the service pressure and temperature requirements above this range wil necessary for other heat pipe applications.
Preferably the invention employs "off the shelf' Swagelok~ type quick-connects on heat pipes 10, as limited by the cited temperature and pressure ranges. For example, Swagek instrumentation brochure No. QC-590-1, April 1993, discloses one example of the panic type of couplings which cari be adapted to this heat pipe 10 application that have pressure rat up to 3,000 psig, but at 70°F. Similarly, temperature ratings with various types of O-rings ext the range of these devices up to the 400°F range, but only at 100 psig.
The selection of particular type of disconnecting valve means 50 and their materials of construction wil determined by the temperature and pressure under which the heat pipe 10 is expected to open A plurality of heat pipes 10 using the present invention would be employed in the "c end" portion of a gas to air heat transfer device; i.e., a heat pipe air heater (not shown). ' "cold end" portion of such an air heater is that location wherein the cooled gas exits from the heater, and the cold inlet air enters. Similarly, the "hot end" of such an air heater is that locat wherein the hot gas enters and the heated air exits. The present invention would generally be applied to the "hot end" portions of the air heater because of the heat pipe 10 operat temperature and pressure. Sometimes hydrogen or other noncondensible gases are producec the heat pipes 10. On the "hot end" portion of the air heater, any hydrogen gas produced is un a sufficient pressure that will cause it to be compressed and only disable a small portion of heat pipe itself. At these elevated pressures, the hydrogen gas is actually driven out through walls of the heat pipe 10; and thus only causes the loss of a small portion of the effective len of the heat pipe 10. In contrast, heat pipes operating on the "cold end" of the air heater are operating at such a high pressure that would cause the hydrogen gas to be either compressed o at a localized end of the heat pipe 10, or to be driven through the walls.
Therefore, a lar portion of the length of the heat pipe 10 is disabled when an amount of hydrogen accumulates. These are the heat pipes 10 which are particularly suited for application of present invention, since the heat pipe at the "cold end" of the air heater may be operating o into the approximately 320°F range, wherein the saturation pressure at this temperature is 8 psia.
Referring to Fig. 4 there is shown a schematic representation of the degassing/evacuat step used in the manufacturing process for heat pipes using the present invention. One enc the heat pipe 10 and its associated disconnecting valve means 50 is partially immersed in a de tank 61 to which heat is applied as shown to increase the temperature of the contents of the 1 pipe 10. Water is provided from a source 62 via line 64 through a volume measuring mean:
of known construction. A valve 68 and a line 70 are provided and removably coupled at 7:
disconnecting valve means 50. A vacuum pump 74, capable of producing vacuums as lov approximately -30" Hg, is connected via line 76 to a tee connection 78 so as to draw a vacs:
on the heat pipe 10. Once the filling and degassing of heat pipe 10 is complete, the vacs providing equipment and water providing equipment would be decoupled from the disconnec~
valve means 50. The heat pipe 10 would then be available for ftufiher processing. The heat 1 itself has an outside diameter ranging from approximately 1'/. inches to approximate) inches, and the spiral fins applied to the outside surface thereof would have an outside diam ranging from approximately 2'/e inches to approximately 3'/z inches. Since the outside diam 5 D, of the preferred disconnecting valve means is approximately 1 inch, the resulting combina~
achieves the desired difference in diameters between that of the disconnecting valve mean:
and the heat pipe 10.
Fig. 5 shows a schematic representation of equipment that would be used to field ser a heat pipe made and used according to the present invention. Fig. 5 shows a single heat F
10 10 with its associated fill tube 52 and disconnecting valve means 50. A
portable field servic apparatus 80, and a vacuum pump 74 having the same vacuum producing abilities as descri earlier, would be provided to perform certain field servicing operations as described earl Apparatus 80 is connected to the heat pipe 10 via a flexible line or hose 82 of desired length, removably coupled thereto at 72. Apparatus 80 would advantageously comprise an arrangers of valves 84, 86, and 88 to permit fluidic communication between the heat pipe 10 (via line and the vacuum pump 74, a gas sample container 90, and a pressure gage 92 as shown. O
the field servicing operations are complete, the portable field servicing apparatus 80 woulc disconnected from the disconnecting valve means 50.
Figs. 6A-6D illustrate several other field servicing operations that are possible thro use of the present invention. Fig. 6A shows the heat pipe 10 before servicing.
Figs. 6B and show how samples of working fluid 18 or visual inspections of the internal portion of the 1 pipe 10 would be performed. For these field servicing operations, the protective plug 54 and disconnecting valve means 50 would be removed to allow an open passageway through the tube 52 into the heat pipe 10. The compression fitting S3 allows this to be accomplished. A
94 and fluid pump means 96 would be used to obtain a. sample of the fluid 18 contained wi the heat pipe 10 and provide it to a liquid sample container 98 via line 100.
A long, sle~
probe or sample line 102 would be extended down into the heat pipe 10 for this purpose shown in Fig. 6B. Alternatively, as shown in Fig. 6C, a visual inspection of the interior por of the heat pipe 10 could be facilitated by means of a known fiberoptic borescope operatively connected via line 106 to video and light providing equipment 108 connected via 110 to a video monitor 112 in known fashion. At the conclusion of such inspections an<
samplings, the disconnecting valve means SO and protective plug 54 would be reattached, a the heat pipe 10 had been restored to its working condition, as shown in Fig.
6D.
While specific embodiments of the invention have been shown and described in de to illustrate the application of the principles of the invention, those skilled in the art appreciate that changes may be made in the form of the invention covered by the follov~
claims without departing from such principles. In some embodiments of the invention, cer features of the invention may sometimes be used to advantage without a corresponding us~
the other features. Accordingly, all such changes and embodiments properly fall within scope of the following claims.
Claims (2)
1. A method of field-servicing a heat pipe apparatus having disconnecting valve means provided on a fill tube connected to an end cap thereof, the disconnecting valve means having a first end removably and fluidically connected to the fill tube, and a second end provided with a removable protective plug, comprising:
removing the protective plug from second end of the disconnecting valve means to provide access to an internal portion of the heat pipe apparatus;
removably coupling a stem portion to the second end of the disconnecting valve means, to provide a fluidic passage through the fill tube into the internal portion of the heat pipe apparatus; and removing the disconnecting valve means from the heat pipe apparatus by loosening a front portion having a compression fitting therein, the front portion being attached to the fill tube, and inserting a sample line through the fill tube into an internal portion of the heat pipe apparatus to obtain a fluid sample therefrom.
removing the protective plug from second end of the disconnecting valve means to provide access to an internal portion of the heat pipe apparatus;
removably coupling a stem portion to the second end of the disconnecting valve means, to provide a fluidic passage through the fill tube into the internal portion of the heat pipe apparatus; and removing the disconnecting valve means from the heat pipe apparatus by loosening a front portion having a compression fitting therein, the front portion being attached to the fill tube, and inserting a sample line through the fill tube into an internal portion of the heat pipe apparatus to obtain a fluid sample therefrom.
2 . A method of field-servicing a heat pipe apparatus having disconnecting valve means provided on a fill tube connected to an end cap thereof, the disconnecting valve means having a first end removably and fluidically connected to the fill tube, and a second end provided with a removable protective plug, comprising:
removing the protective plug from second end of the disconnecting valve means to provide access to an internal portion of the heat pipe apparatus;
removably coupling a stem portion to the second end of the disconnecting valve means, to provide a fluidic passage through the fill tube into the internal portion of the heat pipe apparatus; and removing the disconnecting valve means from the heat pipe apparatus by loosening a front portion having a compression fitting therein, the front portion being attached to the fill tube, and inserting a thin fiberoptic borescope through the fill tube into an internal portion of the heat pipe apparatus to visually inspect same.
removing the protective plug from second end of the disconnecting valve means to provide access to an internal portion of the heat pipe apparatus;
removably coupling a stem portion to the second end of the disconnecting valve means, to provide a fluidic passage through the fill tube into the internal portion of the heat pipe apparatus; and removing the disconnecting valve means from the heat pipe apparatus by loosening a front portion having a compression fitting therein, the front portion being attached to the fill tube, and inserting a thin fiberoptic borescope through the fill tube into an internal portion of the heat pipe apparatus to visually inspect same.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US53939795A | 1995-10-05 | 1995-10-05 | |
| US08/539,397 | 1995-10-05 | ||
| CA002183617A CA2183617C (en) | 1995-10-05 | 1996-08-19 | Field serviceable fill tube for use on heat pipes |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002183617A Division CA2183617C (en) | 1995-10-05 | 1996-08-19 | Field serviceable fill tube for use on heat pipes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2274882A1 true CA2274882A1 (en) | 1997-04-06 |
Family
ID=31189065
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002274882A Abandoned CA2274882A1 (en) | 1995-10-05 | 1996-08-19 | Field serviceable fill tube for use on heat pipes |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2274882A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119164219A (en) * | 2024-11-21 | 2024-12-20 | 烟台东方能源科技有限公司 | A modular HVAC heat exchanger |
-
1996
- 1996-08-19 CA CA002274882A patent/CA2274882A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119164219A (en) * | 2024-11-21 | 2024-12-20 | 烟台东方能源科技有限公司 | A modular HVAC heat exchanger |
| CN119164219B (en) * | 2024-11-21 | 2025-01-10 | 烟台东方能源科技有限公司 | A modular HVAC heat exchanger |
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