Combined food and wipe heater

Abstract

A combination heater device including an inner pouch with an activation agent and an outer pouch with a heat generating material adapted to generate heat upon contact by the activation agent. A first package containing at least one wipe is in heat absorbing contact with the heater as is a second package containing a food element requiring heating. A package holding element maintains the first and second package in contact with the heater.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of Heater Device application filed Jul. 22, 2008, having Ser. No. 12/220,146, which is a continuation-in-part of Pan In Pan Heater application filed Oct. 4, 2007, having Ser. No. 11/973,178.

BACKGROUND

This invention relates to a device for heating the contents of a container and for keeping it warm. More particularly, the invention relates to a self-contained heater device that allows the contents such as food in a container to be heated.

Often times, it is desirable to heat food and other items at a location remote from a source of heat such as a stove or oven. Other times it is desirable to take warmed or hot food and other items from the place of heating to another location, such as a picnic, school or church basement, scout meeting and any of the myriad of events that do not meet or gather where heat is available. Sometimes the location is in a location where fire is not permitted, such as a class room or outdoors during the dry season. It is also important for military personnel to have access to warm food, particularly when deployed in locations remote from their base or station.

One such self-contained warmer is disclosed in U.S. Patent Application Publication No. US 2007/0034202, to Punphrey et al. in which a container with an exothermic composition is used to heat a vessel. A membrane is used to cover the exothermic composition, which is then activated by removal of the membrane. Various compositions are disclosed that are based on iron oxidation chemistry. The heater is in direct contact with the container and must be put on a heat-resistant surface to be used without damage.

U.S. Pat. No. 6,705,309 discloses a self-heating or self-cooling container in which tubular walls defining an internal cavity into which steam or hot air is placed as a source of heat. This, of course, requires a source of that heated material.

Other heater devices for food generate heat by chemical reaction, and in so doing generate hot gases, steam or hot water vapor, which is potentially hazardous to the user and which may, in some instances, contribute to pollution of the environment.

It would be a great advantage if a way of heating containers could be developed that have a controlled release of heat that is within acceptable safety limits.

Another advantage would be to provide a way of heating containers that produces heat over an extended period of time, rather than simply having an exothermic reaction that lasts a few minutes or less.

Yet another advantage would be to provide a way to generate heat by an exothermic reaction without releasing any gas, steam or hot water vapor to outside the device.

Also, often when someone is in a remote location, such as camping or the like, there is not a convenient facility for cleaning up one's self or one's equipment such as eating utensils and the like. It would be of great advantage if the food and the means to clean up after cooking could be combined into one product.

Other advantages will appear hereinafter.

SUMMARY

The unique aspect of this invention is that a controlled, dispersed exothermic reaction can be used to heat or cook the contents of a container quickly and effectively while maintaining the heat for an extended period of time without releasing any of the reaction products to outside of the device. Also included in the product is a quantity of personal hygiene wipes or towels that can be used to clean up after cooking or eating. The combination in one package provides excellent convenience.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one component of this invention.

FIG. 2 is a perspective view of the preferred embodiment prior to assembly.

FIG. 3 is a side view of the embodiment of FIG. 2 after assembly.

DETAILED DESCRIPTION

In its simplest form, the present invention is a combination of a self-contained heater, a food package, and some wipes or towels, all in one package at the time of use. By the term “wipe” is meant any object such as a personal hygiene wipe, tissue, towel, handkerchief, wash cloth or other object used as a cleaning device, such as to cleanse silverware or one's hands. The food package may be any package containing comestibles or other material that is to be heated. Typical food boxes are what is known in the military as MRE, which is an acronym for “meals ready to eat.” The heater is activated by causing an activation agent in an inner pouch to transfer to an outer pouch that contains heat generating materials. Because the outer pouch is sealed, vapor or other byproducts of the reaction are kept inside and do not affect the user.

It is desirable to provide more than one personal hygiene wipe. Any practical number of wipes is contemplated by this invention, for example and not by way of limitation, packs of three or five or more, and the invention is not limited to any number of wipes. Preferred are those wipes made of spun lace fabric, such as those from rayon and polyester fibers

The preferred heater is described in a commonly owned co-pending U.S. Patent Application having Ser. No. 11/584,145, filed Oct. 20, 2006, the disclosure of which is incorporated herein in its entirety. The heater of this application features an inner pouch with an activation agent therein, an outer pouch with a heat generating agent and a vacuum therein, such that the vacuum assists in transferring the activation agent into intimate contact with the heat generating agent rapidly and thoroughly.

The use of a heater of this type with food packages is described in a commonly owned co-pending U.S. Patent Application having Ser. No. 12/220,146, filed Jul. 22, 2008, the disclosure of which is incorporated herein in its entirety. The various activation devices used to break the seal between the inner and outer pouch are also examples of the means for activating the present invention.

As seen in FIG. 3, a food package 11 and a wipe pouch 13 are on each side of heater 17. Heater 17 is shown in FIG. 1 as having an outer pouch 19 with heat generating material 21 inside it. Inner pouch 23 includes an activation agent 25 inside it. Pouch 23 also has a seal 27 which, in this embodiment is a rigid plastic piece 27 with a score line 29. Flexing pouch 23 at seal 27 causes score 29 to split open, allowing the activation agent 25 to flow into pouch 19. Other seals are also contemplated, including those described in a commonly owned co-pending U.S. Patent Application having Ser. No. 12/152,013, filed May 12, 2008, the disclosure of which is incorporated herein in its entirety.

Pouch 19 preferably has a vacuum inside it, most preferably ranging from about 9 psi to about 13 psi. Alternatively, pouch 23 can have an elevated pressure of from about 15 to 19 psi.

In FIG. 2, the packages 11 and 13 are shown separated from the heater 17. In FIG. 3, the product has been assembled and a package holding element 31 holds them together. Alternatively, the elements can be attached to the pouch via an adhesive or simply placed together on a table or other surface.

Preferred is an outer pouch made from Aclar®, which is a polychlorotrifluoroethylene (PCTFE) material manufactured and sold by Honeywell International Inc. Aclar film is crystal clear, biochemically inert, chemical-resistant, nonflammable, and plasticizer- and stabilizer-free. Aclar laminates provide a wide range of gauges and thus barrier levels to allow flexibility in selecting the optimum barrier level for the chemical system chosen. Other similar pouch materials may be used as well. All that is required is that the material have a functional moisture and vapor barrier for the other components of the invention.

In a preferred embodiment, inner pouch is made from a heat stamp foil that is moisture impervious. In a preferred embodiment, the foil pouch includes a rigid portion with a score line adapted to rupture when flexed to empty the activation agent into the outer pouch

There are a number of combinations of heat generating materials and activating agents that are suitable for use in the present invention. The selection of specific components is to be based upon cost, compatibility, ease of control of the exotherm, and other factors.

The preferred activating material of this invention is water. This is plentiful and safe, and reacts with a number of materials to produce an exothermic reaction.

The preferred heat generating material is a solid formed from several components that, when free from moisture, are stable for up to three to five years or more, and which react when moisture is present to generate heat. The preferred solid is made from crystalline calcium oxide, a zeolite powder, and a polyalkyl glycol such as polyethylene glycol. The amount of activation material, such as water, is preferably from about 75 to 125 weight percent, based upon the total weight of heat generating material. Approximately equal amounts by weight of water and heat generating material is the preferred ratio.

The amount of calcium oxide ranges from about 30 to 70 weight percent, the amount of polyethylene glycol ranges from about 15 to about 35 weight percent, and the amount of zeolite ranges from about 15 to about 35 weight percent, based on the total weight of heat generating material. Preferred is about 25 weight percent each of the polyethylene glycol and zeolite and about 50 weight percent calcium oxide

The heat generation material most preferred, using the above components includes a calcined calcium oxide. This material is available as a small particle size, with a diameter less than about 0.2 mm, and as a particle of somewhere between 0.2 and 0.8 mm. Larger particles are ground and smaller ones sieved, and the calcium oxide is then calcined. It has been found to be effective to calcine for at least 60 to 120 minutes, and preferably about 90 minutes, at temperatures above 500° C., and most preferably at about 550° C. for that period of time. The calcined calcium oxide is, of course, desiccated to prevent any contamination by moisture.

More than 150 zeolite types have been synthesized and 48 naturally occurring zeolites are known. They are basically hydrated alumino-silicate minerals with an “open” structure that can accommodate a wide variety of positive ions, such as Na+, K+, Ca₂+, Mg₂+and others. These positive ions are rather loosely held and can readily be exchanged for others in a contact solution. Some of the more common mineral zeolites are: analcime, chabazite, heulandite, natrolite, phillipsite, and stilbite. An example mineral formula is: Na₂Al₂Si₃O₁₀-16H₂O. Zeolites, by their nature, are finely porous structures that are “hungry” for water and that have the ability to hold heat. In the present invention, the activation agent, water in the preferred embodiment, enters into the zeolite pores, trapping the water as it is heated by reacting with the calcium oxide, thus storing heat, providing a longer, more evenly distributed supply of useable heat.

The polyethylene glycol component of the heat generating material is admixed with the calcium oxide and zeolite and placed in the outer container as described above. When the activation agent, water, is introduced into the heat generating material, the polyethylene glycol coats the calcium oxide and zeolite, further delaying the exothermic reaction between calcium oxide and water, and adding to the utility of this invention.

The present invention provides a significant advantage over the prior art in several ways. Because the outer container is sealed, as described above, the exothermic reaction when heat is generated does not release steam or other vapor as do presently available heaters. In addition, the heater device of this invention is much more effective that what has been done in the past. The heater of this invention has been used to heat products to 150° F. within 5 minutes and maintained the heat at or above 140° F. for 50 minutes. Prior art devices take 12 minutes to reach only 140° F. and only hold that temperature for 20 minutes. Thus the food can be cooked and kept warm for more than enough time to consume it. In addition, the wipes are kept warm in the same manner.

Also, because there is a vacuum in the pouch containing the heat generating material, breaking the seal causes the activating agent to pour into contact throughout the container, resulting in proper heat generation. In a series of tests of this embodiment, 100% of the activations resulted in warm personal hygiene wipes. Then a similar set of packages were prepared, with the only change being no vacuum inside the outer pouch, only 30% of the wipes achieved the desired temperature.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. A combination heater device, comprising:

a heater having a first side for transferring heat and a second side for transferring heat, including an inner pouch with an activation agent and an outer pouch with a heat generating material adapted to generate heat upon contact by the activation agent, and further including a seal for selectively opening the inner pouch to permit a heat generating reaction;

a first package in heat absorbing contact with the first side of the heater and including at least one wipe, the first package having opening to provide access to the at least one wipe; and

a second package in heat absorbing contact with the second side of the heater and including at least one food element requiring heat to prepare for consumption.

2. The device of claim 1 which further includes a package holding element maintaining the first and second package in contact with the heater.

3. The device of claim 1, wherein a pressure differential is formed between the pressure in the outer pouch and the inner pouch such that the inner pouch has a higher pressure than the outer pouch, whereby, upon opening the inner pouch, the activation agent is driven into the outer pouch to react with the heat generating material.

4. The device of claim 3, wherein the pressure differential is caused by a vacuum inside the outer pouch.

5. The device of claim 1, wherein the actuation agent is water and the heat generating material is crystalline calcium oxide.

6. The device of claim 5, which further includes powdered zeolite admixed therein with the calcium oxide.

7. The device of claim 6, which further contains polyethylene glycol admixed with the calcium oxide and powdered zeolite.

8. The device of claim 7, wherein the amount of calcium oxide ranges from about 30 to about 70 weight percent, the amount of polyethylene glycol ranges from about 15 to about 35 weight percent, and the amount of zeolite ranges from about 15 to about 35 weight percent, based on the total weight of heat generating material.

9. The device of claim 8, wherein the amount of water ranges from about 75 to about 125 weight percent, based on the total weight of heat generating material,

10. The device of claim 1, wherein the first package contains from 3 to 5 wipes.

11. The device of claim 10, wherein the second package is a MRE.

12. The device of claim 1, wherein the outer pouch forms the first and second sides for transferring heat to the first and second packages.

13. The device of claim 1, wherein the outer pouch is formed from a vapor impervious material.

14. The device of claim 12, wherein the inner pouch is formed from a foil material having a rigid portion with a score line adapted to rupture when flexed to empty the activation agent into the outer pouch.

15. A combination heater device, comprising:

a heater having a first side for transferring heat and a second side for transferring heat, including an inner pouch formed from a foil material and containing an activation agent and an outer pouch with a heat generating material comprising calcium oxide ranges from about 30 to about 70 weight percent, the amount of polyethylene glycol ranges from about 15 to about 35 weight percent, and the amount of zeolite ranges from about 15 to about 35 weight percent, based on the total weight of heat generating material, the activation agent comprising water in an amount ranging from about 75 to 125 weight percent, based on the total weight of heat generating material, the heater further including a seal for selectively opening the inner pouch to permit a heat generating reaction;

a first package in heat absorbing contact with the first side of the heater and including at least one wipe, the first package having opening to provide access to the at least one wipe; and

a second package in heat absorbing contact with the second side of the heater and including at least one food element requiring heat to prepare for consumption.

16. The device of claim 15, with further includes a package holding element maintaining the first and second package in contact with the heater.

17. The device of claim 15, wherein a pressure differential is formed between the pressure in the outer pouch and the inner pouch such that the inner pouch has a higher pressure than the outer pouch, whereby, upon opening the inner pouch, the activation agent is driven into the outer pouch to react with the heat generating material.

18. The device of claim 17, wherein the pressure differential is caused by a vacuum inside the outer pouch.

19. The device of claim 15, wherein the first package contains from 3 to 5 wipes.

20. The device of claim 19, wherein the second package is a MRE.