 Variable pressure thermal insulating jacket |
| OF PREFERRED EMBODIMENTS In a preferred form of the invention shown in FIG. 8 the gas pressure in ... |
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| Determining a masking level for a subband in a subband audio encoder |
| OF A PREFERRED EMBODIMENT The present invention provides a method, a device, and systems for ... |
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| Strip casing unit with downstream multi-stand continuous rolling mill |
| We claim: 1. In a process for making hot-rolled steel strip from a striplike continuously cast ... |
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| Heat treatment cup for a beverage container |
| ACCORDING TO THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION FIGS. 1 and 2 show a heat ... |
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| Deformable tubular container |
| The present invention provides a new tubular container which can contain at least two products ... |
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| Energy control device |
| I claim: 1. A heat transfer sensing apparatus for operating a movable thermal barrier for covering ... |
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| Solar energy collector having an absorber element of coated foil |
| An object of the invention is to provide an improved solar energy collector. Another object is to ... |
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| Interiorly tensioned solar reflector |
| I claim: 1. In a solar reflector having a first form member, a second form member, said first and ... |
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| Double floor |
| The object of the invention is to provide a double floor with floor plates of the above-described ... |
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| Food steaming apparatus |
| In accordance with this invention there is provided food steaming apparatus comprising a tubular ... |
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Compositions for thermal energy storage or thermal energy generation
| Details |
Inventors: Salyer, Ival O.;
Assignee: Phase Change Laboratories, Inc. (San Diego, CA)
Primary Examiner: Bonner; Melissa
Assistant Examiner:
Attorney, Agent or Firm: Killworth, Gottman, Hagan & Schaeff
A composition for thermal energy storage or thermal energy generation comprising a silica based gel or dry powder in the form of silica particles containing a water/urea phase change material for thermal energy storage or an endothermic or exothermic compound for thermal energy generation. The water/urea phase change material stores and releases at least 50 cal/gm of thermal energy in freezing and melting, and has a melting and a freezing point in the range of -11.degree. C. to -15.degree. C. The endothermic compound is preferably ammonium nitrate, urea, or combinations thereof. The exothermic compound is preferably calcium oxide or calcium chloride. The thermal energy storage composition may find use in a variety of applications including medical wraps, food servingware, and "blue ice" for cold packs or food storage. The thermal energy generation composition may find use as medical wraps, food servingware, and refrigerators when endothermic and medical wraps, food servingware, heaters, stadium seats, boots, vests, caps ear muffs, and scarves when exothermic. |
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DETAILED DESCRIPTION The present invention meets that need by providing a silica based gel or dry powder in the form of silica particles containing a water/urea phase change material for thermal energy storage or an endothermic or exothermic compound for thermal energy generation.
In one embodiment, there is provided a water/urea phase change material contained in a particulate silica matrix.
Preferably, the silica particles are hydrophobic silica particles surface treated with 0.
5-5 parts per hundred by weight of a silane coupling agent or silicone resin.
The mixture of silica and phase change material (PCM) is preferably in the form of a free-flowing, conformable powder-like mix, i.
e.
PCM/silica dry powder, which may be prepared in accordance with U.
S.
Pat.
Nos.
5,106,520 or 5,282,994, which are incorporated herein by reference.
The water/urea PCM/silica dry powder preferably has a thermal energy storage of greater than 30 cal/gm.
In this embodiment, the silica is preferably present in an amount of from 30 to 40% by weight and the water/urea phase change material is present in an amount of from 70 to 60% by weight.
This type of structure is especially desirable for medical wrap applications, but is of interest in other applications such as for tableware.
Thus, the PCM/silica dry powder may be disposed in a liquid impervious polymer film or a metal foil enclosure to form a medical wrap.
The PCM/silica dry powder may also be disposed in the plastic housing of containers such as tableware items or ice cream freezers.
Likewise, the water/urea phase change material/silica dry powder composition may be disposed in the inner chamber of a housing where the housing includes an inner cavity for containing a heat sensitive item such as a flight recorder.
Such a device is disclosed in copending application Serial No.
08/044,819, incorporated herein by reference.
The water/urea phase change material is a water/urea clathrate or inclusion compound which melts and freezes congruently in the range of about -11
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Heat Accumulators 
