Thermal transfer blanket system
12007175 ยท 2024-06-11
Assignee
Inventors
Cpc classification
Y02E60/14
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F28D2020/0091
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D2020/0021
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D2020/0017
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D20/0056
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F28D17/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A thermal transfer blanket includes a flexible container comprising a thermally insulating material. A thermal energy storage media is disposed within the flexible container.
Claims
1. A thermal transfer blanket, comprising: a flexible container comprising a thermally insulating material; and a thermal energy storage media configured to act as a heat sink for storing and releasing thermal energy and disposed within the flexible container, wherein the thermal transfer blanket is non-powered; wherein the thermally insulating material can withstand process temperatures of 300? F. or more; and wherein the thermal energy storage media comprises a metal oxide, non-oxide ceramic, or a metal and has a thermal conductivity of 35 W/m-K or more at 25? C.
2. The thermal transfer blanket of claim 1, further comprising a thermally transparent layer in direct thermal communication with the thermal energy storage media.
3. The thermal transfer blanket of claim 2, wherein the thermally transparent layer comprises fiberglass coated with a fluoropolymer.
4. The thermal transfer blanket of claim 1, further comprising a thermocouple in thermal communication with the thermal energy storage media.
5. The thermal transfer blanket of claim 1, wherein the thermally insulating material comprises a ceramic batting and a layer of fabric comprising glass that surrounds the ceramic batting.
6. The thermal transfer blanket of claim 1, wherein the thermally insulating material comprises foam insulation.
7. The thermal transfer blanket of claim 1, wherein the thermal energy storage media comprises at least one material chosen from AlN, BeO, BN, diamond, Al.sub.2O.sub.3, and a metal, and wherein the thermal energy storage media has a specific heat capacity of 300 J/kg.Math.K or more at 25? C.
8. The thermal transfer blanket of claim 7, wherein thermal energy storage media is pure aluminum.
9. The thermal transfer blanket of claim 1, wherein the thermal energy storage media comprises one or more layers of tiles, the tiles in each layer being bonded together by an elastomeric polymer.
10. The thermal transfer blanket of claim 9, wherein the thermal energy storage media comprises 2 to 10 layers of the tiles, the 2 to 10 layers of the tiles comprising at least one layer having tiles of a first length and at least one layer having tiles of a second length that is longer than the first length.
11. The thermal transfer blanket of claim 1, wherein the thermal energy storage media comprises pellets.
12. The thermal transfer blanket of claim 11, wherein at least a portion of the pellets are in a matrix material comprising an elastomeric polymer.
13. The thermal transfer blanket of claim 11, wherein the pellets comprise large pellets and small pellets, the large pellets having interstitial spaces therebetween and the small pellet being sufficiently small to fit in the interstitial spaces between the large pellets.
14. The thermal transfer blanket of claim 11, wherein the thermal energy storage media further comprises at least one plate comprising metal.
15. The thermal transfer blanket of claim 1, further comprising a heat storage flap attached to the flexible container.
16. The thermal transfer blanket of claim 15, wherein the heat storage flap comprises at least one thermal resistive pad.
17. A thermal transfer blanket system, comprising: a thermal transfer blanket, comprising: a flexible container comprising a thermally insulating material; and a thermal energy storage media configured to act as a heat sink for storing and releasing thermal energy and disposed within the flexible container, wherein the thermal transfer blanket is non-powered; wherein the thermally insulating material can withstand process temperatures of 300? F. or more; and wherein the thermal energy storage media comprises a metal oxide, non-oxide ceramic, or a metal and has a thermal conductivity from about 100 W/m-K to about 500 W/m-K and a specific heat capacity from about 300 J/kg.Math.K to about 1500 J/kg.Math.K at 25? C., and a thermal resistive pad, stacked on the thermal transfer blanket, comprising: a thermal insulating material; a shell layer surrounding the thermal insulating material, the shell layer being a fabric; and a thermocouple proximate the shell layer, wherein the shell layer can withstand temperatures of at least 120? F., and wherein the thermal resistive pad is configured to at least partially reduce a thermal energy transfer rate for the thermal transfer blanket.
18. The thermal transfer blanket system of claim 17, wherein the thermal insulating material comprises a material chosen from a fabric comprising glass, a ceramic batting, a foam, and combinations thereof.
19. The thermal transfer blanket system of claim 17, wherein the fabric of the shell layer comprises a non-stick coating.
20. A thermal transfer blanket system, comprising: a thermal transfer blanket, comprising: a flexible container comprising a thermally insulating material; and a thermal energy storage media disposed within the flexible container, wherein the thermal transfer blanket is non-powered; wherein the thermally insulating material can withstand process temperatures of 300? F. or more; and wherein the thermal energy storage media has a thermal conductivity of 35 W/m-K or more at 25? C., and a specific heat capacity of about 300 J/kg.Math.K or more at 25? C., and one or more thermal resistive pad, comprising: a thermal insulating material; a shell layer surrounding the thermal insulating material, the shell layer being a fabric; and a thermocouple proximate the shell layer, wherein the shell layer can withstand temperatures of at least 120? F., wherein the one or more thermal resistive pad is applied to the thermal transfer blanket to reduce a temperature transferred by the thermal transfer blanket.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrates aspects of the present teachings and together with the description, serve to explain the principles of the present teachings.
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(17) It should be noted that some details of the figures have been simplified and are drawn to facilitate understanding rather than to maintain strict structural accuracy, detail, and scale.
DESCRIPTION
(18) Reference will now be made in detail to the present teachings, examples of which are illustrated in the accompanying drawings. In the drawings, like reference numerals have been used throughout to designate identical elements. In the following description, reference is made to the accompanying drawings that form a part thereof, and in which is shown by way of illustration specific examples of practicing the present teachings. The following description is, therefore, merely exemplary.
(19) The devices of the present disclosure can provide the ability to repair, for example, coatings, sealants and/or thermal set composites on the exterior of vehicles, for example aircraft, or other objects in very austere environments with few tools and no electrical power. For example, the devices can heat adhesive, sealant, prepreg or other organic resin-containing repair materials to achieve a reasonable temperature to cure the organic resin at high temperatures, such as, for example, 120? F. or above. The devices are easily portable and can be used to repair coatings outside and in situations where the resin is initially at low temperatures, such as 20? F. or lower. The devices of the present disclosure can also function as non-powered hot or cold storage device that can be used to heat or cool various items from, for example, about ?65? F. to about 1,700? F., about 120? F. to about 1200? F., or about 120? F. to about 600? F.
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(21) The flexible container 102 can comprise any suitable thermal insulating material 152 described herein. The thermal insulating material maintains thermal energy within the thermal energy storage media 104 so as to reduce unwanted heat loss, as well as to protect users from burns that could occur by touching the thermal energy storage media 104.
(22) The thermal energy storage media 104 comprises a material that acts as a heat sink for storing and releasing thermal energy. Suitable materials can comprise, for example, at least one material chosen from metal oxide or non-oxide ceramics, such as AlN, BeO, BN (either cubic BN or hexagonal BN), diamond, Al.sub.2O.sub.3, and metals, such as aluminum, copper, silver, brass, iron, gold, steel and combinations thereof, with aluminum, silver and copper having the most suitable combinations of thermal conductivities and specific heat capacities. The metals, such as aluminum, copper, silver, gold and iron, can be pure or alloyed. The term pure is defined to mean at least 99% by weight pure. Thus, pure aluminum as used herein includes at least 99% by weight aluminum. The thermal conductivities and specific heat capacities of several of these materials are shown Table 1 below. Materials such as AlN, BN and BeO, which have relatively high thermal conductivities and specific heat capacities will be able to store relatively large amounts of thermal energy per unit mass, while also being capable of transferring the thermal energy quickly, either for purposes of storing or releasing the thermal energy. Examples of suitable thermal conductivities range from about 35 W/m-K to about 500 W/m-K or higher, such as about 100 W/m-K to about 500 W/m-K, such as about 150 W/m-K to about 400 W/m-K, or about 200 W/m-K to about 400 W/m-K (as measured at 25? C.). Examples of suitable specific heat capacities range from about 300 J/kg.Math.K to about 1500 J/kg.Math.K or higher, such
(23) TABLE-US-00001 TABLE 1 Cu Au THERMAL PROPERTIES AlN BeO Al2O3 Al METAL METAL METAL THERMAL CONDUCTIVITY (W/m-K) 170-200 209-330 35 204 386 310 SPECIFIC HEAT CAPACITY (J/kg .Math. K) 740 750-1020 880 902 385 129 DIELECTRIC CONSTANT 9.7 6.1-7.5
as about 500 J/kg.Math.K to about 1000 J/kg.Math.K, or about 700 J/kg.Math.K to about 950 J/kg.Math.K (as measured at 25? C.). It is possible that materials with lower thermal conductivities (e.g., Al.sub.2O.sub.3) and/or lower specific heat capacities (e.g., gold) can be used, but they will not function as effectively for quickly charging the thermal blanket, quickly delivering heat energy or quickly cooling an object and/or for providing a desired amount of heat energy to the object. In the case where a longer time period for charging of the thermal blanket is not an issue and/or where it is desirable to deliver the heat or cold for long periods of time without too quickly reducing the thermal blanket, a material with a high specific heat and a low thermal conductivity could be desirable. For example, while Al.sub.2O.sub.3 has a suitable specific heat, its thermal conductivity is only about 35 W/m-K, and so it is not as good a candidate as AlN, BN or BeO for quickly charging and quick heating and/or cooling. However, Al.sub.2O.sub.3 may be suitable for other applications where longer periods of time for charging, heating and/or cooling are acceptable. Additionally, these and the other ceramics listed are electrical insulators, which is an advantage in situations where electrical conductivity is an issue. Of the metals shown in
(24) The thermal energy storage media 104 employed in the thermal transfer blanket 100 of
(25) The elastomeric polymer 114 can be any polymer that is flexible and can withstand relatively high temperatures of at least 120? F., such as about 300? F. or more, such as about 400? F. to about 650? F. An example of such an elastomeric polymer is silicone. An example of a commercially available silicone is 3145 RTV, available from Dow Corning of Midland, Michigan.
(26) The thermal transfer blanket 100 can comprise any desired number of layers 110 of the thermal energy storage media 104. For example, thermal transfer blanket 100 can comprise about 1 to about 10 of the layers 110, such as about 2 to about 6 of the layers 110. The number of layers can be chosen to provide a desired amount of thermal energy storage capacity for the thermal transfer blanket 100 and the thickness of the layers 110. The thickness of each layer 110 can be any suitable thickness, such as about 0.1 inch to about 1 inch, or about 0.15 inch to about 0.25 inch, or about 0.0157 inch. The thicker the layers 110 are, the fewer that may be used to achieve a desired thermal energy storage capacity. However, using larger numbers of thin layers can provide for a more flexible thermal transfer blanket than using fewer numbers of thicker layers to achieve the same thermal energy storage capacity.
(27) The layers 110 can be attached to the thermal transfer blanket in any suitable manner. For example, the layers 110 can be attached to the flexible container 102 using an adhesive, such as silicone, at an end of each of the layers 110. In an example, the two or more layers 110 of tiles 112 are not attached directly to each other, thereby providing increased flexibility for the thermal transfer blanket 100.
(28) In an alternative example, the layers 110 can be allowed to float freely within the flexible container 102. In this example, thermally transparent layer 118 can act to enclose and retain the layers 110 within the flexible container 102. The thermally transparent layer 118 can be in direct thermal communication with the thermal energy storage media 104. Thermally transparent layer 118 is made of a material that can allow the thermal energy stored in the thermal energy storage media 104 to be released through the thermally transparent layer 118. For example, the thermally transparent layer 118 can be sufficiently thin (e.g., 0.001 inch to 0.01 inch thick, such as about 0.005 inch thick) so as to allow ready transfer of heat therethrough. If desired, the thermally transparent layer 118 can also be non-stick in order to avoid sticking to the object being heated or cooled. A commercial example of such a non-stick material is ARMALON?, which is a non-porous TEFLON (a polytetrafluoroethylene) coated fiberglass fabric that is known for use in composite fabrication.
(29) In an example, the thermal transfer blankets described herein include at least one thermocouple. For instance, thermocouples 106, 108 can be arranged as shown in
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(32) The thermal transfer blanket 100 of
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(34) The thermal transfer blanket 100 of
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(36) The thermal transfer blanket 100 of
(37) The plate 120 and pellets 122 can comprise any of the materials described herein for thermal energy storage 104. For example, plate 120 and pellets 122 can comprise at least one material chosen from AlN, BeO, BN, diamond, Al.sub.2O.sub.3, and metals, such as aluminum, copper, silver, gold, brass, iron, steel and combinations thereof. In an example, both the plate 120 and pellets 122 comprise aluminum, such as pure aluminum. The pellets 122 can be coated or uncoated. In an example, the pellets 122 are coated with a chromate conversion coating for reducing corrosion and/or hardening the pellet surface. Corrosion can reduce heat transferability so that reducing corrosion can be desirably for maintaining the heat transfer efficiency of the pellets. One example of a commercially available chromate conversion coating is BONDERITE? (formerly known as ALODINE?), from Henkel Adhesives of D?sseldorf, Germany.
(38) The pellets 122 can have a uniform size. Alternatively, the pellets 122 can comprise a plurality of sizes so as to improve packing density, and therefore increase the amount of thermal energy that can be stored per unit volume of the pellets, which can be desirable for making thermal blankets that are less bulky while still storing sufficient thermal energy for curing. For example, referring to
(39) The elastomeric polymer for matrix material 124 can comprise the same materials as those described above for the elastomeric polymer 114, such as silicone that is capable of withstanding temperatures of at least 120? F., such as about 300? F. to about 650? F. or more, have high elongation and be tear resistant. An example of a commercially available silicone is 3145 RTV, available from Dow Corning of Midland, Michigan.
(40) Pellets 122 are incorporated in the matrix material 124 and additional pellets 122 are disposed so as to float freely in a space enclosed on one side by the combination of the thermally transparent layer 118 and the matrix material 124 so as to be sealed within the flexible container 102. The matrix material 124 can thus form a layer proximate the thermally transparent layer 118 and may help to provide a relatively smooth support surface for the pellets 122 disposed above the matrix material 124. Such a smooth surface may be beneficial when curing polymers for providing a smooth cured polymer surface. The combination of pellets and matrix material 124 provide good flexibility for the thermal transfer blanket 100, while the optional plate 120 can increase the thermal energy storage capacity and rigidity of the blanket.
(41) In an example, the one or more plates 120 comprise materials with higher specific heat than the material used for the pellets 122 to increase thermal energy storage. In an example for low temperature cooling or heating applications, the plates 120 can be dry ice or paraffin in the form of blocks. While paraffin wax has a low melting point, it has a heat capacity of 3260 J/kg.Math.K, and thus could store relatively large amounts of thermal energy at colder temperatures compared with, for example, aluminum. For low temperature or high temperature cooling or heating applications, the one or more plates 120 can comprise blocks of organic resins, ceramics or metals that have higher specific heat than the material used for the pellets. As an example, the one or more plates 120 can comprise phenolic resin, which is able to withstand temperatures of 600-700? F. and has a heat capacity of about 1250-1650 J/kg.Math.K.
(42) The thermal transfer blanket 100 of
(43) The thermocouples 106 and 108 can be attached to the fabric of containers 128 (including thermally transparent layer 118) using any suitable technique. One exemplary technique for attached thermocouples 106 is to bond them to the thermally transparent layer 118 using a high temperature adhesive, such as silicone (e.g., 3145 RTV available from Dow Corning of Midland, Michigan). In cases where thermally transparent layer 118 includes a non-stick coating, such as PTFE (e.g., TEFLON), the non-stick coating can first be removed from the location where the one or more thermocouples 106 are to be bonded using any suitable technique, such as, for example, a tetra etch, as is generally well known in the art. The one or more thermocouples 106 are then attached to the thermally transparent layer 118. The one or more thermocouples 108 can be attached to, for example, a place holder 130 that is attached to the container 128. The place holder can be, for example, a piece of fabric or other material attached to the container 128 by stitching, so that the thermocouple 108 is maintained in a desired position in the pellets 122 that are free floating in container 128.
(44) The thermal transfer blanket 100 of
(45) The thermal transfer blanket 100 of
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(49) The thermal resistive pad 150 can be employed as a stand-alone pad that is separate from the thermal transfer blankets described herein. Alternatively, at least one thermal resistive pad 150 can be attached to the thermal transfer blanket 100. For example, one or more of the thermal resistive pads 150 can be attached to the flexible container 102 of any of the thermal transfer blankets 100, either in place of, or in addition to, the heat storage flap 119. In an example, the heat storage flap 119 comprises at least one thermal resistive pad 150, such as 2 to 4 of any of the thermal resistive pads 150 of
(50) The thermal resistive pads 150 can be made of any number of flexible insulating materials and can be stacked between the thermal transfer blankets and a repair patch to reduce the thermal transfer rate. When the thermal storage device is fully charged it may too hot (or cold) and a particular thermal energy transfer rate maybe desired. A thermal resistive pad or pads can be placed between the thermal transfer blanket and the repair patch to reducing thermal energy transfer rate. During heating or cooling, thermal resistive pads can be added or removed to maintain the heating rate as the thermal transfer blanket is depleted, or to speed up the heating rate or limit the repair to a maximum temperature. Thermal couples on the thermal resistive pads and the thermal transfer blanket can be monitored and/or data recorded with a battery operated handheld device to facilitate proper cure repair.
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(52) The thermal transfer blankets of the present application can be used for various heating or cooling applications. Examples of such applications include: curing any kind of organic resin or cements, even in cold environments; accelerating the cure of organic composites for repairs for aircraft, cars, motorcycles, bikes or sporting goods; keeping items hot or cold for storage or shipping without melting or release of any liquid, such as water from ice.
Example
(53) A plate of aluminum about ? thick was put in an oven at 350? F. to absorb the heat. The hot plate was placed on top of a piece of frozen prepreg (which specified a cure temperature greater than about 250? F. for at least about 90 min. for curing). A layer of ARMALON and woven glass fabric (acting as a thermal resistive pad) was positioned between the prepreg and the heated aluminum. The heat from the aluminum cured the prepreg.
(54) While the present teachings have been illustrated with respect to one or more implementations, alterations and/or modifications can be made to the illustrated examples without departing from the spirit and scope of the appended claims. In addition, while a particular feature of the present teachings may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular function. Furthermore, to the extent that the terms including, includes, having, has, with, or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term comprising. Further, in the discussion and claims herein, the term about indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the intended purpose described herein. Finally, exemplary indicates the description is used as an example, rather than implying that it is an ideal.
(55) It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompasses by the following claims.