Claims:We Claim:
1. A household appliance (10), comprising :
- at least one compartment (12) to store multiple items ;
- a flow control valve (16) connected between a condenser (14) and a first evaporator (18) ;
- a compressor (19) connected to said first evaporator (18);
- a refrigerant flowing from said condenser (14) into said first evaporator (18) via said flow control valve (16) ;
characterized in that :
- a freeze-drying compartment (20) comprising a tray holder (22) having multiple trays (24), said freeze-drying compartment (20) adapted to freeze-dry and to preserve at least one said item in said appliance (10).

2. The household appliance (10) as claimed in claim 1, wherein said freeze-drying compartment (20) comprises a cover (28) enclosed on said tray holder (22), at least one portion of said cover (28) acts as an inner surface of said freeze-drying compartment (20).

3. The household appliance (10) as claimed in claim 2, wherein said cover (28) comprises at least one cavity (30) to drain liquid formed in said freeze-drying compartment (20) during at least one operational event of said appliance (10).

4. The household appliance (10) as claimed in claim 2, wherein said cover (28) is cylindrical in shape and is made of any one of the materials like sheet metal, aluminum, plastic.

5. The household appliance (10) as claimed in claim 1, comprises a vacuum pump (32) positioned in a casing (34), said vacuum pump (30) connected to said freezer-drying compartment (20) via said cover (28).

6. The household appliance (10) as claimed in claim 1, wherein said freeze-drying compartment (20) comprises a heating element (36) fitted under each of said multiple trays (24), one end of said heating element (36) of each of said multiple trays (24) is connected to a control unit (38) via said cover (28).

7. The household appliance (10) as claimed in claim 1, wherein said freeze-drying compartment (20) comprises a second evaporator (40) wrapped around said cover (28), said second evaporator (40) is connected between said flow control valve (16) and said compressor (19) of said appliance (10).

8. The household appliance (10) as claimed in claim 7, wherein said second evaporator (40) is chosen from a group of evaporators comprising a wrap-around evaporator, a roll-bond evaporator.

9. The household appliance (10) as claimed in claim 1, wherein said freeze-drying compartment (20) comprises a door (42) fitted on said appliance (10) , said door (42) is operated to access said multiple items preserved in said freeze-drying compartment (20).

10. The household appliance (10) as claimed in claim 1, wherein said freeze-drying compartment (20) comprises a gasket (44) fitted in proximity to said door (42) of said freeze-drying compartment (20), such that, said door (42) comes into contact with said gasket (44) to seal said freeze-drying compartment (20) and to create a vacuum inside said freeze-drying compartment (20).
, Description:The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention
[0001] This disclosure relates to a household appliance. More particularly, it relates to the household appliance having a freeze-drying compartment for preserving at least one item in the household appliance.

Background of the invention
[0002] To preserve the food for long time, the food should not have moisture as moisture is good for fungal & bacterial growth. To preserve the food for long time, we have traditional method like drying the fruits by using sunlight, canning, etc. As a food preservation method, freeze-drying has several benefits over others. To maintain fresh flavor and nutritional value, frozen food requires uniform, below freezing storage conditions. High-temperature processing to produce dehydrated and canned foods degrades the flavor, texture, and nutritional content, despite producing a product that may be stored without refrigeration. Freeze-drying preserves freshness, color, and aroma similar to frozen food without relying on refrigeration, like canned or dehydrated food. Freeze-drying is intended to remove water from food, but not the flavor, color, texture or nutritional value.

[0003] A US patent application 6163979 discloses a method for controlling a freeze drying process, a frozen product is arranged on temperature controlled surfaces in an air-evacuated chamber and undergoes a main drying and after-drying phase. During the main drying phase, the temperature of the ice surrounding the product is continuously measured. The pressure in the chamber and/or the temperature of the surfaces are modified during transition from the main drying phase to the after-drying phase.

Brief description of the invention:
[0004] It is an object of the invention to provide a household appliance with a freeze-drying compartment to freeze-dry and to preserve at least one item stored in the appliance.

[0005] The objects are solved by the household appliance having the features according to claim 1.

[0006] The invention relates to a household appliance. The household appliance comprises at least one compartment to store multiple items. The appliance further comprises a flow control valve connected between a condenser and a first evaporator. The appliance further comprises a refrigerant flowing from the condenser into the first evaporator via the flow control valve. The appliance further comprises a freeze-drying compartment comprising a tray holder having multiple trays. The freeze-drying compartment is adapted to freeze-dry and to preserve at least one item stored in the appliance.

[0007] A feature of this invention is that, the freeze-drying compartment comprises a cover enclosed on the tray holder. At least one portion of the cover acts as an inner surface of the freeze-drying compartment.

[0008] Another feature of this invention is that, the cover comprises at least one cavity to drain liquid formed in the freeze-drying compartment during at least one operational event of the appliance.

[0009] Another feature of this invention is that, the cover is cylindrical in shape and is made of any one of the materials like sheet metal, aluminum, plastic.

[0010] Another feature of this invention is that, the appliance comprises a vacuum pump positioned in a casing. The vacuum pump is connected to the freezer-drying compartment via the cover.

[0011] Another feature of this invention is that, the freeze-drying compartment comprises a heating element fitted under each of the multiple trays, one end of the heating element of each of the multiple trays is connected to a control unit via the cover.

[0012] Another feature of this invention is that, the freeze-drying compartment comprises a second evaporator wrapped around the cover. The second evaporator is connected between said flow control valve and a compressor of the appliance.

[0013] Another feature of this invention is that, the second evaporator is chosen from a group of evaporators comprising a wrap-around evaporator, a roll-bond evaporator.

[0014] Another feature of this invention is that, the freeze-drying compartment comprises a door fitted on the appliance. The door is operated to access the multiple items preserved in the freeze-drying compartment.

[0015] Another feature of this invention is that, the freeze-drying compartment comprises a gasket fitted in proximity to the door of the freeze-drying compartment, such that, the door comes into contact with the gasket to seal the freeze-drying compartment and to create a vacuum inside the freeze-drying compartment.

[0016] With the above-disclosed household appliance, the integrated freeze-drying compartment of the appliance helps in preserving the multiple items that are stored in the appliance for a longer durations. The above arrangement utilizes the existing components of the appliance to provide both the refrigeration and the freeze-drying process to the customer. As there are no additional components used to complete the freeze-drying process, unlike in the conventional methods, the above-disclosed arrangement provides a cost-effective simple solution to the users.

[0017] The above-disclosed arrangement reduces the time consumed in pre-preparation process of the items that need to be preserved for long durations (like drying in the sun) and the effort that is used to complete the pre-preparation process. The freeze- drying process helps the users of the appliance, in retaining the taste and the tenderness of the items that needs to be preserved for a long time. The usage of the freeze-drying compartment reduces the food waste by freeze-drying the leftovers and makes those a perishable product. The vacuum pump enclosed in the casing has an insulation that is used to reduce the noise generated during the operation of the vacuum pump.

Brief description of the accompanying drawings
An embodiment of the disclosure is described with reference to the following accompanying drawings;
[0018] Figure 1 illustrates a household appliance, in accordance with an embodiment of this invention, and
[0019] Figure 2 illustrates a freeze-dryer compartment in the appliance, according to an embodiment of the present invention; and
[0020] Figure 3 illustrates a cover and a second evaporator of the freeze-drying compartment, according to an embodiment of the present invention.

Detailed description of the embodiments
[0021] Figure 1 illustrates a household appliance, in accordance to one embodiment of the invention. The household appliance 10 comprises at least one compartment 12 to store multiple items. The appliance 10 comprises a flow control valve 16 connected between a condenser 14 and a first evaporator 18. The appliance 10 comprises a refrigerant, which flows from the condenser 14 into the first evaporator 18 via the flow control valve 16. The appliance 10 further comprises a freeze-drying compartment 20 comprising a tray holder 22 having multiple trays 24. The freeze-drying compartment 20 adapted to freeze-dry and to preserve at least one of the multiple items in the appliance 10.

[0022] Further, the construction of the household appliance 10 and the components of the household appliance 10 are explained as follows. According to one embodiment of the invention, the household appliance 10 is refrigerator chosen from a group of refrigerators comprising a single-door refrigerator, a multi-door refrigerator and the like. The appliance 10 further comprises a refrigeration compartment 12 (a) and at least one freezer compartment 12(b). However, the type of compartment is not restricted to the above-disclosed compartments, but a convertible compartment is also made in the appliance in addition to the refrigeration compartment 12(a), freezer compartment 12(b) and the freeze-drying compartment 20. According to one embodiment of the present invention, the appliance 10 is a multi-door refrigerator comprising a refrigeration compartment 12(a), a freezer compartment 12(b), a convertible compartment 12 (c) and a freeze-drying compartment 20 as shown in the figure 1.

[0023] Figure 2 illustrates a freeze-dryer compartment in the appliance, according to an embodiment of the present invention. The freeze-drying compartment 20 is made adjacent to the convertible compartment 12(c). The position of the freeze-drying compartment 20 is not restricted as shown in the figure1, but can be positioned in the appliance 10 based on the requirement. The appliance 10 further comprises a compressor 19 connected to the first evaporator 18. A person skilled in the art knows the working of the components of the appliance 10 like the condenser 14, the evaporators (18, 40), the flow control valve 16 and the compressor 19. The appliance 10 further comprises a control unit 38 adapted to control at least one operation of the appliance 10. The control unit 38 comprises at least one radio button to activate or deactivate the freeze-drying process in the freeze-drying compartment 20.

[0024] The appliance 10 comprises a vacuum pump 32 positioned in a casing 34. According to one embodiment of the invention, the vacuum pump 32 is located at the bottom portion of the appliance 10 as shown in the figure 1. The casing 34 comprises an insulation placed around the vacuum pump 32 to reduce the noise generated by the vacuum pump 32 during the freeze-drying process.

[0025]The freeze-drying compartment 20 is made as an integral part of the appliance 10. The freeze-drying compartment 20 comprises a cover 28 enclosed on the tray holder 22 in such a way that, at least one portion of the cover 28 acts as an inner surface for the freeze-drying compartment 20. The cover 28 is made in the form of a cylinder. However, the shape of the cover 28 is not restricted to the cylindrical shape, but can be any feasible shape like a rectangular shape, a circular shape, a spherical shape or the like, that can be fitted into the appliance 10. The cover 28 is made of any one of the materials comprising a sheet metal, aluminum, plastic and the like as known to a person skilled in the art.

[0026] The material of the cover 28 is chosen to withstand variation in at least one parameter comprising temperature, pressure and the like. According to one embodiment of the invention, the cover 28 (in the form of the cylinder and made of the sheet metal) acts as the freeze-dryer compartment 20. A foam material 46 that acts as an insulation is inserted between the cover 28 and a shell cabinet 45 of the appliance 10, during the assembly of the freeze-dryer compartment 20 in the appliance 10.

[0027] The cover 28 comprises at least one cavity 30 to drain liquid formed in the freeze-drying compartment 20 during at least one operational event of the appliance 10. At least one operational event of the appliance 10 is chosen from a group of operational events like refrigeration event, defrost event, freeze-drying event and the like. The freeze-drying compartment 20 comprises a heating element 36 fitted under each of the multiple trays 24. One end of the heating element 36 of each of the multiple trays 26 is connected to a control unit 38 via the cover 28. Each of the heating element 36 of the respective tray of the tray holder 22 comprises a cable 37. The cables 37 of all the heating elements 36 are connected to the control unit 38 through at least one cavity 30 made on the cover 28. The control unit 30 supplies the voltage to the heating elements 36 through these respective cables 37 during the freeze-drying process, to dry at least one item of the multiple trays 24.

[0028] The vacuum pump 30 is connected to the freeze-drying compartment 20 via the cover 28. As mentioned above, the cover 28 comprises a cavity 30 to receive the connection from the vacuum pump 30. According to the present invention, the cover 28 comprises three cavities 30, one to drain the liquid formed in the freeze-drying compartment 20 and other to connect the heating elements 36 to the control unit 38 through respective cables 37 and yet another cavity to receive the connection from the vacuum pump 30.

[0029] Figure 3 illustrates a cover and a second evaporator of the freeze-drying compartment, according to an embodiment of the present invention. The freeze-drying compartment 20 comprises a second evaporator 40 wrapped around the cover 28.The second evaporator 40 is connected between the flow control valve 20 and the compressor 19 of the appliance 10.The second evaporator 40 is chosen from a group of evaporators comprising a wrap-around evaporator, a roll-bond evaporator. The second evaporator 40 receives the refrigerant from the flow control valve 16, when the first evaporator 18 is in non-operating condition. The second evaporator 18 freeze and cool the multiple items stored in the freeze-drying compartment 20.

[0030] The freeze-drying compartment 20 comprises a door 42 fitted on the appliance 10. The door 42 as illustrated in FIG. 1 and FIG. 2 is operated to access the multiple items preserved in the freeze-drying compartment 20. The door 42 is attached to the compartment 20 using any one of the fitting techniques comprising a screw-fit, a snap fit , a fastener and the like. A handle 43 is made on the door 42 for closing and opening operation, when the user is accessing the inner portion of the compartment 20. According to one embodiment, the door 42 is made of a transparent material, such that, the user can view the contents of the compartment 20 and a status of the freeze-drying process. According to another embodiment of the invention, the door 42 is made of the same material as that of the other compartment doors to maintain the uniformity and the atheistic look of the appliance 10.

[0031] The freeze-drying compartment 20 comprises a gasket 44 fitted in proximity to the door 42 of the freeze-drying compartment 20. The door 42 comes into contact with the gasket 44 to seal the freeze-drying compartment 20 and to create a vacuum inside the freeze-drying compartment 20 when the door is closed. The gasket 44 is made larger than the cover 28 and is fitted at an open end of the cover 28.

[0032] A method of working of the household appliance is explained as follows. The refrigerant is made to pass through the condenser 14, evaporators (18,40) and the compressor 19 to complete a refrigeration cycle, such that the ice is formed in the freezer compartment 12 (b) and the cool air is directed into the refrigeration compartments 12 (a) and 12 (c) . The first evaporator 18 freezes/cools the freezer compartment 12(b) and other refrigeration compartments 12 (a, c) during the normal operating condition of the appliance 10. During this condition, the flow control valve 16 connected to the first evaporator 18 and the second evaporator 40, directs the refrigerant into the first evaporator 18 to complete the refrigeration cycle. The first evaporator 18 is made as a fin type structure as known in the conventional appliances. When the first evaporator 18 is in ON condition, the flow control valve 16 restricts the flow of the refrigerant into the second evaporator 40.

[0033] When the user of the appliance 10 wants to preserve at least one item, and then the freeze-drying process is activated by activating a radio button present on the control unit 38 of the appliance 10. Upon detecting a signal from the control unit 38, the flow control valve 16 directs the refrigerant towards the second evaporator 40 wrapped around the cover 28 in the freeze-drying compartment 20. The refrigerant flowing in the second evaporator 40 cools the freeze-drying compartment 20 and freezes at least one item stored in the compartment 20. Once the refrigerant is flown from the second evaporator 40, it reaches the compressor 19 and the refrigeration cycle continues. Based on the signal from the control unit 38, the flow control valve 16 directs the refrigerant in either one of the evaporators (16, 40) of the appliance 10.

[0034] According to another embodiment of the invention, upon detecting the signal from the control unit 38 and based on the requirement to run both the freezer compartment 12(b) and the freeze-drying compartment 20, the flow control valve 16 allows a predefined amount of refrigerant towards the first evaporator 18 and the remaining refrigerant towards the freeze-drying compartment 20. With the above method, both freeze-drying process and ice formation process is achieved.

[0035] When at least one item of the freeze-drying compartment 20 undergoes the freezing process, then, the vacuuming and the drying process occurs simultaneously. The control unit 38 upon detecting the completion of the freezing process activates the vacuum pump 32 to vary the pressure in the compartment 20 and to create vacuum in the compartment 20. Simultaneously, the control unit 38 provides signals to the heating elements 36 placed under each of the tray 24 of the freeze-drying compartment 20, to dry at least one item that has been frozen earlier. The freeze-drying process takes approximately a day or more to complete and to prepare at least one item for preserving for a long duration. At least one item stored in at least one of the compartments of the appliance is chosen from a group of items, which are edible like fruits, vegetables, meat, milk products and the like.

[0036] Another feature of this invention is that, the freeze-drying compartment 20 comprises a gasket 44 fitted in proximity to the door 42 of the freeze-drying compartment 20, such that, the door 42 comes into contact with the gasket 44 to seal the freeze-drying compartment 20 and to create a vacuum inside the freeze-drying compartment 20. With the above-disclosed household appliance 10, the integrated freeze-drying compartment 20 of the appliance 10 helps in preserving the multiple items that are stored in the appliance 10 for longer durations. The above arrangement utilizes the existing components of the appliance 10 to provide both the refrigeration and the freeze-drying process to the customer. As there are no additional components used to complete the freeze-drying process, unlike in the conventional methods, the above-disclosed arrangement provides a cost-effective simple solution to the users.

[0037] The above-disclosed arrangement reduces the time consumed in pre-preparation process of the items that need to be preserved for long durations (like drying in the sun) and the effort that is used to complete the pre-preparation process. The freeze- drying process helps the users of the appliance 10 in retaining the taste and the tenderness of the items that needs to be preserved for a long time. The usage of the freeze-drying compartment 20 reduces the food waste by freeze-drying the leftovers and makes those a perishable product. The vacuum pump 32 enclosed in the casing 34 has an insulation that is used to reduce the noise generated during the operation of the vacuum pump 32.

[0038] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this disclosure. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

List of Reference Signs
10 household appliance
12 one compartment
14 condenser
16 flow control valve
18 first evaporator
19 compressor
20 freeze-drying compartment
22 tray holder
24 multiple trays
28 cover
30 at least one cavity made on the cover
32 vacuum pump
34 casing
36 heating element
38 control unit
40 second evaporator
42 door of the freeze-drying compartment
43 handle of the door of the freeze-drying compartment
44 gasket
45 U-shell cabinet
46 Foam insulation