HEATER DEVICE

Abstract

A heater device for heating objects, including a compartment having a heat generating material and a second compartment having an activation material to generate heat upon mutual contact. The compartments are adapted to present a heating surface to the object to be heated. A divider is positioned in the compartments forming a barrier to maintain separation between reaction components until opened by an opening member positioned in alignment with the divider. An access element is movable into contact with the barrier to permit a heat generating reaction there between.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of Heater Device application filed Dec. 7, 2009, having Ser. No. 12/632,308, which 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 classroom 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.

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.

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, 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 are known in the military as MRE, which is an acronym for “meals ready to eat.”

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of one component of the preferred embodiment of this invention.

FIG. 2 is a back elevational view of the embodiment of FIG. 1.

FIG. 3 is a sectional, side elevation view of the embodiment of FIG. 1 taken along line 33.

FIG. 4 is a sectional view of a second component of the preferred embodiment of this invention.

FIG. 5 is a section view of the preferred embodiment of this invention in FIG. 3, with the second component of FIG. 4, showing the device prior to activation.

FIG. 6 is a sectional view of the device of FIG. 5 after activation of the device.

FIG. 7 is a view of an object to be heated by the device of this invention.

DETAILED DESCRIPTION

The device, 10 generally in FIG. 1, includes a first compartment 11 and a second compartment 13, separated in this embodiment by a penetrable 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 provided is an opening member 17, shown mounted on the second compartment 13, on the end 19 of compartment 13 away from divider 15. Opening member has threads 17a that will hold an optional cap, not shown. End 19 is not in communication with the inside of compartment 13. Compartment 13 also has an end 21 remote from divider 15. In a preferred embodiment, the junction 23 of the side of compartment 13 and its bottom, 21, are curved as shown in FIG. 1. This prevents accumulation of components in compartment 13 from collecting in the corners where access to them is limited by their being accumulated in the square corners.

Inside compartment 13 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 29, shown in FIG. 4, is designed to fit into opening member 17 and penetrate divider 15. Penetration of divider 15 will cause the activation material 27 to admix with the heat generating material 25 to generate heat. In the following figures, reference is made to heat generating material 25 and activation material 27, which are shown here in FIG. 1 and not shown in the remaining figures for purposes of simplicity. These two reaction agents are present in the chambers as described below.

FIG. 2 shows the back of device 10, which, in a preferred embodiment, includes a nonwoven material back 31 with a tab 33 that can be used to fasten device 10 to an object to be heated. One side 35 of device 10 is open after initial manufacture and is sealed after the heat generating material 25 and activation material 27 in chambers 13 and 11 respectively.

FIG. 3 illustrates device 10 in section with upper chamber 11 and lower chamber 13 in position to hold the activation material 27 and heat generating material 25 as described above. Divider 15 is shown as being attached to the side walls of chamber 11 at 15a and 15b, and extending down to its lowest point 15c. Low point 15c is in the middle of the width of chambers 11 and 13, so that the activation material 27 in chamber 11 is near low point 15c when the device 10 is upright as shown in the figures. To activate device 10, divider 15 is opened to permit the activation material 27 flow into chamber 13 and react with heat generating material 25.

FIG. 4 illustrates preferred access element 29 that has a circular cross section over it's entire length. Access element 29 also includes a central bore 41 that extends nearly the full length thereof. Access element 29 includes a conically tapered tip 43 that is capable of penetrating divider 15 when pressed against it, such as lowest point 15c. At the other end of access element 29 is a head portion 45 of a first diameter d₁ that tapers at chamfer 47 to the diameter of the body 49 of access element 29 with a diameter d₂ at taper 43 and along the entire length of body 49 up to chamfer 47. Central bore 41 thus extends from solid tip 43 to head portion 45.

Body 49 has a first slot 51 that functions to transfer activation material 27 through it to enter compartment 13 and react with heat generating material 25, as described below.

Body 49 has a second slot 53 that functions to allow steam or other gasses generated in compartment 13 during the reaction of heat generating material 25 with activation material 27 to travel up body 49 and into upper chamber 11 to exit through opening member 17 through exhaust hole 55.

FIGS. 5 and 6 illustrate the use of access element 29 in device 10. FIG. 5 illustrates device 10 before activation and FIG. 6 illustrates device 10 after activation.

In FIG. 5, access element 29 is inserted into opening member 17 and positioned above hole 55 that is sealed by membrane 57. At this point, heat generating material 25 is isolated from activation material 37. An insulating layer 31 is located on the back side of device 10 and the other side is not insulated, so the heat generated will go through the front or not insulated side of FIG. 1.

In FIG. 6, access element 29 has been fully inserted into device 10, rupturing or penetrating membrane 57 and further extending down to puncture the lower end 15c of divider 15. At this point, the activation agent 27, not shown for simplicity but shown in FIG. 1, passes through first slot 51 from chamber 11 into chamber 13, and begins to react with heat generating material 25, again shown in FIG. 1. Heat generating reactions such as those describe below and contemplated for device 10 will generate steam or other gaseous byproducts. The reaction, at point 61 in chamber 13, generates gas or steam that flows from the reaction point 61 into first slot 51, up central bore 41, through second slot 53 and into chamber 11. If the pressure in chamber 11 increases, the steam or gas may also flow up central bore 41 and out hole 55. Because the end 45 of access element 29 is recessed in opening member 17, the steam does not directly heat anything that might adversely affect someone using device 10. Arrow 63 describes generally the path of the steam.

In operation, referring again to FIGS. 1 and 2, an object to be heated, 71 in FIG. 7, is placed on the front face of device 10 shown in FIG. 1. In a preferred embodiment, object 71 is about ½ the size of device 10, so that device 10 can be folded to put object 71 in contact with both halves of the front of device 10. The folded device 10 is then secured by placing tab 33 in attaching contact with back 31. In a preferred embodiment, tab 33 has a look and latch element that engages nonwoven back 31 to thus hold object 71 in contact with device 10. When it is desired to heat object 71, access element 29 is inserted into device 10 to function as described above and generate sufficient heat to achieve the desired temperature.

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 activating material may include a small amount of an added liquid chemical that extends the time that water can hold the heat once it is generated. Ethylene glycol is a preferred liquid chemical heat holding agent. The amount of ethylene glycol may range from about 0.2% by weight to about 2.0% by weight, the percentages being based upon the weight of the water.

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 of these reaction components.

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 heater of this invention has been used to heat products such as MRE packages 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.

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 heater device for heating objects, comprising:

a first compartment having a quantity of heat generating material therein;

a second compartment having a quantity of activation material therein capable of activating the heat generating material upon mutual contact;

the first compartment and second compartment together being sized to present a heating surface to the object to be heated;

a divider positioned in the first compartment and extending into the second compartment forming a barrier to maintain separation between the activation material and the heat generating material;

an opening member mounted on the device positioned in alignment with the barrier of the divider; and

an access element positionable in the open member and movable into contact with the barrier of the divider to open the barrier and 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 device further includes a heat absorbing material on the device remote from the heating surface.

3. The device of claim 1, wherein the opening member is a tube mounted on the end of the first compartment.

4. The device of claim 3, wherein the tube is adapted to have a removable top.

5. The device of claim 1, wherein the access element is a longitudinal member having an axis and a diameter sized to enter the opening member and having a length sufficient to reach the barrier of the divider, whereby movement of the access element against the barrier opens the barrier to permit access of the activation material to the heat generating material.

6. The device of claim 5, wherein the access element includes a central bore along the axis providing an opening between the first and second chamber when positioned inside them.

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, whereby pressure on the pressure pad moves the access element along its axis.

8. The device of claim 7, where the central bore includes at least one opening transverse to the axis for providing access of the activation material to the passage and the first compartment.

9. 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.

10. The device of claim 15, device further includes a heat absorbing material on the device remote from the heating surface.

11. The device of claim 18, which further includes an object to be heated and a tab on the heat absorbing material, such that the device is adapted to be folded over the object so that the heat absorbing material is external to the object and the heating surface is proximate the object, and the tab is adapted to maintain the folded device with the heating surface proximate the object.

12. The device of claim 19, wherein the object is a package containing food to be heated.

13. A heater device for heating objects, comprising:

a first compartment having a quantity of calcium oxide therein;

a second compartment having a quantity of water therein capable of activating the heat generating material upon mutual contact;

the first compartment and second compartment together being sized to present a heating surface to the object to be heated;

a divider positioned in the first compartment and extending into the second compartment forming a barrier to maintain separation between the water and the calcium oxide;

an opening member mounted on the device positioned in alignment with the barrier of the divider; and

an access element positionable in the open member and movable into contact with the barrier of the divider to open the barrier and permit access of the water to the calcium oxide to permit a heat generating reaction there between, wherein the access element is a longitudinal member having an axis and a diameter sized to enter the opening member and having a length sufficient to reach the barrier of the divider, whereby movement of the access element against the barrier opens the barrier to permit access of the water to the calcium oxide.

14. The device of claim 13, device further includes a heat absorbing material on the device remote from the heating surface.

15. The device of claim 14, which further includes an object to be heated and a tab on the heat absorbing material, such that the device is adapted to be folded over the object so that the heat absorbing material is external to the object and the heating surface is proximate the object, and the tab is adapted to maintain the folded device with the heating surface proximate the object.

16. The device of claim 15, wherein the object is a package containing food to be heated.