WO2010053467A1

WO2010053467A1 - Heater device

Info

Publication number: WO2010053467A1
Application number: PCT/US2008/012501
Authority: WO
Inventors: Jere Ferguson; Raquel Carvallo
Original assignee: DONOVAN INDUSTRIES Inc; Donovan Ind Inc
Current assignee: DONOVAN INDUSTRIES Inc; Donovan Ind Inc
Priority date: 2008-11-06
Filing date: 2008-11-06
Publication date: 2010-05-14
Anticipated expiration: 2011-05-06

Abstract

A heater device formed from first and second compartments separated by a penetratable divider. An access element is positioned to puncture the divider. The first compartment presents a heating surface to an object and has a heat generating material inside it. The second compartment has an activating agent. An access element is in into contact with the divider to permit a heat generating reaction. The access element includes a concentric passage with an opening for providing access of the water to the passage and the first compartment and includes at least one pointed tip for puncturing the divider.

Description

HEATER DEVICE

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. Patent 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.

It would be a great advantage if a way of heating containers could be developed that has 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 activate heaters for containers that is simple and effective and that does not have the potential for pre-activation. Other advantages will appear hereinafter.

SUMMARY

The unique aspect of this invention is that a controlled, dispersed exothermic reaction can be used to heat the contents of a container quickly and effectively while maintaining the heat for an extended period of time. The heat generating reaction is activated by an access element that is not in position to cause the activation material to contact the heat generating material until that is desired by the user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a side elevation view of the preferred embodiment of this invention.

FIGURE 2 is a sectional view of an activator element for use with the preferred embodiment of the invention.

DETAILED DESCRIPTION

In its simplest form, the present invention is a two component heater that has a surface on which objects can be heated upon activation of the two components to cause a heat generating reaction. Examples of objects, by way of example and not by way of limitation, that can be heated are towels, wipes, cushions, hats, gloves and other apparel and food packages and the like. 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."

An example of such a heater is described in a commonly owned co-pending U.S. Patent Application having Serial No. 11/584,145, filed October 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 present invention includes a different activation mechanism than has been available at this time.

The device, 10 generally in Fig. 1, includes a first compartment 11 and a second compartment 13, separated in this embodiment by a penetratable divider 15 that keeps the contents of the compartments separated from each other. It is preferred that divider 15 have some thickness separating the walls of the compartments, to provide a larger area that will be penetrated as described below. In an alternative, equally effective embodiment, second compartment 13 can be a separate container inside first compartment 11. Also alternatively, the two compartments can be placed adjacent to one another. Also provided is an opening member 17, shown mounted on the second compartment 13, on the end 19 of compartment 13 away from divider 15. End 19 is not in communication with the inside of compartment 13. Compartment 1 1 also has an end 21 remote from divider 15. Inside compartment 11 is a quantity of heat generating material 25 that will undergo a chemical reaction and generate heat when contacted by an activation material, such as material 27 inside compartment 13. An access element shown by arrow 29 enters opening member 17 and penetrates divider 15, causing the activation material 27 to admix with the heat generating material 25 to generate heat that warms surface 23 and thus any object placed in contact with surface 23. Opening member 17 may be fixed, or capped, or removably openable by, for example, threaded cap 28. Alternatively, opening member 17 may include a seal such as a washer at its outer end that is also penetrated by arrow 29.

The preferred access element of this invention, that would pass through opening member 17 as shown by arrow 29, is shown in Fig. 2. The access element includes a body portion 31 with an axially concentric bore hole 33 or chimney that extends to the outer end 35 where pressure is applied to force the body in the direction of arrow 29 in Fig. 1. Outer end 35 may be in full communication with bore 33 or the bore 33 may not fully pass through outer end 35. The other end of body 31 terminates in a pair of pointed tapers 37 that are sufficiently sharp to puncture divider 15 and allow admixing of the chemical reactants. Body 31 also includes one or more transverse holes 39. Transverse holes 39 provide an opening for the activation agent to pass into bore 33 and out tapers 37. Body 31 includes a larger portion with a bevel edge 41 that fixes its position in opening 17.

Possible venting may also be desired if bore 33, as shown, extends to outer end 35 prevent pressure buildup by providing a path for gasses and vapors to escape. In addition, transverse holes 41 allow steam to enter the compartment 13 to heat that portion of the device, thus further increasing the efficiency of the device.

The compartments may be 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.

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, basd 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: Na₂Al₂Si₃Oi_O-IoH₂O. 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 unless bore 33 extends to end 35. In this case, only small amounts of steam or other vapors will be released. 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 ⁰F 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

CLAIMS:

1. A heater device for heating objects, comprising: a first compartment having a quantity of heat generating materials therein, the first compartment being sized to present a heating surface to the object to be heated; a second compartment having a quantity of activation material for activating the heat generating materials upon contact there between, the second compartment being proximate the first compartment and maintains separation between the activation material and the heat generating material; an opening member mounted proximate the second compartment and positioned in alignment with an area of the second compartment; and an access element positionable in the open member and movable into contact with the second compartment area to permit access of the activation material to the heat generating material to permit a heat generating reaction there between.

2. The device of claim 1, wherein the first and second compartments are formed from a single container and are separated by a penetratable divider and the access element is positioned to contact the divider.

3. The device of claim 1, wherein the opening member is a tube mounted on an end of the first compartment proximate the second compartment and the cylinder is in sealed contact with the second compartment.

4. The device of claim 3, wherein the tube includes a removable top.

5. The device of claim 1, wherein the access element is a longitudinal member having a diameter sized to enter the opening member and having a length sufficient to reach the second compartment, whereby pressure on the access element in the opening member causes a portion of the second compartment to open to permit the access of the activation material to the heat generating material.

6. The device of claim 5, wherein the access element includes an end adapted to puncture the area of the second compartment it contacts when the pressure is applied.

7. The device of claim 6, wherein the access element includes an enlarged pressure pad on the opposite end from the end in contact with the second compartment.

8. The device of claim 7, where the access element includes a central axis and a passage concentric with the axis, the passage extending to the end adapted to puncture the area of the second compartment and the passage having an opening transverse to the axis for providing access of the activation material to the passage and the first compartment.

9. The device of claim 8, where the end also including at least two pointed tips outside the passage.

10. The device of claim 1, wherein the access element is stored outside the opening member prior to use.

11. The device of claim 1 , wherein the first compartment is at a lower pressure than the first compartment by an amount sufficient to increase the rate of transfer of the activation material to the heat generating material when access is made.

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

13. The device of claim 12, which further includes powdered zeolite admixed therein with the calcium oxide.

14. The device of claim 13, which further contains polyethylene glycol admixed with the calcium oxide and powdered zeolite.

15. The device of claim 14, 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.

16. The device of claim 15, wherein the amount of water ranges from about 75 to about 125 weight percent, based on the total weight of heat generating material.

17. A heater device for heating objects, comprising: a first and second compartments formed from a single container and separated by a penetratable divider and the access element is positioned to contact the divider, the first compartment having a quantity of heat generating material, the first compartment being sized to present a heating surface to the object to be heated; the second compartment having a quantity of activation material for activating the heat generating material upon contact there between; a tube mounted on an end of the first compartment proximate the second compartment and positioned in alignment with the penetratable divider; and an access element positionable in the tube and movable into contact with the penetratable divider to permit access of the water to the crystalline calcium oxide to permit a heat generating reaction there between.

18. The device of claim 17, where the access element includes a central axis and a passage concentric with the axis, the passage extending to the end adapted to puncture the penetratable divider and the passage has an opening transverse to the axis for providing access of the water to the passage and the first compartment, the end also including at least two pointed tips for puncturing the penetratable divider.

19. The device of claim 17, 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, and the amount of water ranges from about 75 to about 125 weight percent, based on the total weight of heat generating material.

20. A heater device for heating objects, comprising: a first and second compartments formed from a single container and separated by a penetratable divider and the access element is positioned to contact the divider, the first compartment having a quantity of crystalline calcium oxide therein, and further includes powdered zeolite and polyethlylene glycol admixed therein with the calcium oxide, the first compartment being sized to present a heating surface to the object to be heated, 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; the second compartment having a quantity of water for activating the crystalline calcium oxide upon contact there between, the amount of water ranging from about 75 to about 125 weight percent, based on the total weight of heat generating material, the first compartment having a lower pressure than the second compartment by from about 2 to about 5 psi to increase the rate of transfer of the water to the crystalline calcium oxide when access is made; a tube mounted on an end of the first compartment proximate the second compartment and positioned in alignment with the penetratable divider; and an access element positionable in the tube and movable into contact with the penetratable divider to permit access of the water to the crystalline calcium oxide to permit a heat generating reaction there between where the access element includes a central axis and a passage concentric with the axis with an opening transverse to the axis for providing^" access of the water to the passage and the first compartment, the end also including at least two pointed tips for puncturing the penetratable divider.