Food inductive heating device and method

Abstract

Heating devices and methods which are particularly useful in vending machines for hot products. Products such as foods, including beverages, contained in individual containers such as cans are rapidly heated to serving temperature by induction heating for delivery to a customer. Various types of products with different heating characteristics are rapidly heated without deleterious effects on the product by varying the power and timing of the inductive heating. The type of product is identified by machine-readable indicia on the container which are automatically scanned prior to heating. The product containers may be agitated before, during and/or after heating to mix the contents and distribute heat evenly. The containers are heated in a manner to safely heat the product without overheating or causing damage to the container. A power management protocol turns off non-essential components of the vending machine while the inductive heater is energized to permit the vending machine to operate on a standard 120 VAC, 15 A electrical circuit without overload.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary vending machine of the invention;

FIG. 2 is a flowchart of the overall operation of the vending machine of FIG. 1;

FIG. 3 is a perspective view of the inductive heating device used in the vending machine of FIG. 1;

FIG. 4 is a cross-sectional view of the inductive heating device of FIG. 3;

FIG. 5 is a schematic drawing showing the major components of the vending machine of FIG. 1;

FIG. 6 is a perspective view of a food container with indicia and the indicia scanner of the invention;

FIG. 7 is a flowchart for a power management feature of the vending machine of FIG. 1; and

FIG. 8 is a flowchart of the indicia, weight and temperature sensing functions of the vending machine of FIG. 1.

Claims

1. A method of heating a container having a food contained therein comprising: providing a food contained in a container that is inductively heatable;detecting whether the food is of a type that has a relatively low heat transfer coefficient;providing an induction heating device;associating the food container in operative relation with the induction heating device; andinductively heating the food container at a relatively high power level for a period of time and thereafter heating at a lower power level until a desired temperature of the container is reached.

2. The method of claim 1 wherein the relatively high rate of heating of the container is a heating rate sufficiently high to damage the container prior to the food in the container reaching 140° F. from a starting temperature of 75° F. and the heating is performed to avoid damage to the container.

3. The method of claim 2 wherein the food has a specific heat less than that of water.

4. The method of claim 3 wherein the food is hot chocolate.

5. The method of claim 2 wherein the high rate of heating is sufficient to damage a container containing hot chocolate but does not damage the same type of container containing a coffee drink comprising coffee and milk and no chocolate.

6. The method of claim 1 wherein said relatively high power level is about 1100 watts of heat output per 9 ounces by volume of food.

7. The method of claim 6 wherein said lower power level is a predetermined percentage of the high power level.

8. The method of claim 7 wherein the food is hot chocolate.

9. The method of claim 1 wherein the induction heating device is provided in a vending machine.

10. The method of claim 1 wherein said induction heating device is controlled by an electronic controller that controls the duration and amount of electrical power that is provided to the inductive heating device.

11. An apparatus for heating a container and the food contained therein comprising: an induction heating coil adapted to permit insertion therein of the container;a power supply for providing electrical power to the induction heating coil to heat the container and the food contained therein; anda controller for controlling the duration and amount of electrical power that is provided to the induction heating coil by the power supply for the heating of the container and the food contained therein, the controller configured to provide a relatively high initial power level to the heating coil for a first period of time and thereafter a lower power level for another period of time.

12. The apparatus of claim 11 wherein said first period of time is based on the typical volume of food to be heated, a starting temperature of the food and the desired final temperature of the food.

13. The apparatus of claim 12 further comprising a temperature sensor for sensing the temperature of the container before heating of the container and to provide starting temperature data to the controller.

14. The apparatus of claim 12 further comprising a temperature sensor for sensing the temperature of the container during heating and to provide temperature data to the controller during heating.

15. The apparatus of claim 11 further comprising a scanning device for reading indicia on a container that is indicative of the type of food contained therein and to provide the type of food data to the controller.

16. The apparatus of claim 15 wherein the controller determines a heating profile for controlling the heating coil based on at least the type of food selected.

17. The apparatus of claim 16 further comprising a temperature sensor for sensing the temperature of the container before heating of the container and to provide starting temperature data to the controller; and a temperature sensor for sensing the temperature of the container during heating and to provide temperature data to the controller during heating.

18. The apparatus of claim 12 wherein the controller is capable of adjusting the amount of heat energy input to the container based on the starting temperature data.

19. The apparatus of claim 17 wherein the controller is capable of adjusting the amount of heat energy input to the container based on the starting temperature data and the temperature data during heating.

20. The apparatus of claim 11 further comprising a food vending machine, the apparatus for heating being contained in the vending machine.