Patent Application
20080066628
The proposed invention is capable of performing under three functional modes: Yogurt maker, refrigerator, and disinfection appliance. People can use mode switch 13 to select the desired function.
Referring to
The mechanism of heating is applied to disinfection and incubation processes. It is achieved by using: a heating element 2 which serves as an electrical heater; one or a group of lamps or the semiconductor heating component is installed onto the bottom of a thermally insulated housing 1, which builds a fermentation compartment 14, which in turn is used to warm the air in compartment 14, thus indirectly heating the cultured milk within the container(s) 6. At the beginning of yogurt preparation, there is a process of disinfection that pumps hot dry air (60° C. to 82° C.) for at least 5 minutes to kill undesired bacteria in thermally insulated compartment 14 and outside of milk container(s) 6 which can block UV to kill the active culture added to the milk. Simultaneously, ultraviolet lamp 3 is turned on to use UV rays to disinfect fermentation compartment 14. Due to the thermal inertia of milk in the container(s) 6, its temperature remains at about 45° C. before the end of disinfection, and thus preserves the active culture. During fermentation, temperature in the compartment 14 is kept at 43° C. with PID (Proportional Integral Derivative) technology. There is a safety door switch 12, which will let controller 11 cut off power to the UV lamp 3, fan 4 and heating element 2 so to prevent human injury during disinfection and incubation. The fan 4 runs during the disinfection and incubation processes to promote temperature homogeneity. The thermal couple 5, on the top of fermentation compartment 14, informs controller 11 the temperature readout in the compartment 14. The controller 11 then dictates temperature of disinfection and incubation processes in the compartment 14. In accordance with
The second mechanism of cooling, which is used to serve as a refrigerator, is achieved using: an evaporator 10 under the ceiling of fermentation compartment 14, refrigerant compressor 7 which compresses refrigerant to high pressures and hot temperatures, which in turn is released from evaporator 10. This refrigerant steam passes through condenser 8 and condenses into liquid, which passes through expansion valve 9, which changes it to low pressure liquid and sends it to evaporate through the evaporator 10 again. Because liquid refrigerant intrinsically possesses a large specific heat, the above method is very efficient in exporting heat from fermentation compartment 14. This cooling mechanism is controlled by controller 11 integrated with thermal couple 5—the air temperature in the fermentation compartment 14 is always kept between 5° C. and 16° C. Therefore, users may treat the machine as an extra refrigerator.
The temperature changes in compartment 14 and curve 15 as well as in milk temperature within container(s) 6 and curve 16 during disinfection and incubation within the fermentation compartment 14 are presented in
This invention also possesses a tertiary function as a kitchen disinfection appliance. Users can use it to disinfect milk container(s) 6 and kitchen utensils such as knives, trays, spoons, and forks. This mode is activated through switch 13. The machine will use ultraviolet light as well as hot dry air at 82° C. in the fermentation compartment 14 to sterilize the targets and fermentation compartment 14. This process requires at least forty minutes.
