WO2024028889A1

WO2024028889A1 - A vacuum drying machine

Info

Publication number: WO2024028889A1
Application number: PCT/IN2023/050733
Authority: WO
Inventors: Ravindra Raghuwanshi
Original assignee: Orchard Farm Fresh Vacuum Dried Fruits (India) Private Limited
Priority date: 2022-08-01
Filing date: 2023-07-31
Publication date: 2024-02-08

Abstract

A vacuum drying machine comprising: an operative top cover (12) and an operative bottom support tray (14) for mesh (20C) defining a vacuum chamber (25); one or more first infrared heaters (12a) provided on an operative lower side of the operative top cover (12), in that, an operative top glass layer being provided beneath the operative top cover (12) such that the one or more first infrared heaters (12a) are interspersed between the operative top cover (12) and the vacuum chamber (25); said heaters (12a) being placed in a matrix form such that adjacent heaters are spaced apart from each other in a pre-defined spacing pattern; and a mesh tray (20) to host target products which are to be vacuum dried, said mesh tray with metal frame (20) being spaced apart from said operative bottom support tray for mesh (14).

Description

A VACUUM DRYING MACHINE

FIELD OF THE INVENTION:

This invention relates to the field of machines and equipment.

Particularly, this invention relates to a vacuum drying machine.

BACKGROUND OF THE INVENTION:

Vacuum drying is a batch operation performed in an air-tight vessel. Using vacuum pumps, the pressure and humidity within the chamber are reduced. By lowering the atmospheric pressure within the chamber, the materials inside dry more quickly through contact with the indirectly heated walls.

There are following types of vacuum dryers: i. Vacuum freeze dryer

Problem associated with this type of dryer is that it is expensive and takes up to 20 to 24 hours for drying. ii. Microwave vacuum drying

Problem associated with this type of dryer is that it is expensive and complicated. Additionally, microwave radiation are potential health hazards iii . V acuum dryers

Problem associated with this type of dryer is that it is placed on a hot plate or trays are under vacuum; the area of fruits and vegetables not in contact of the hot plate does not dry / dehydrate. iv. Infrared vacuum dryers

Problem associated with this type of dryer is that, when slices / whole or cut fruits and vegetables are placed on trays or plates, of the dryer, to dry / dehydrate, it exposes only upper surface of the slices / whole or cut fruits and vegetables. Also, the surface of the plate or tray is not nonstick; hence, there are problems while removing such slices / whole or cut fruits and vegetables from the tray on which slices / whole or cut fruits and vegetables are dried - as melted sugar particularly of sweet fruit/s sticks to surfaces on which it resides.

Radiant dehydration is one kind of advanced rapid, low-temperature drying method. When infrared radiation is applied to food products, infrared energy, under vacuum, is applied and absorbed by moisture in the food products which, in turn, creates a large inside vapour pressure differential between interior and exterior of product. Under vacuum condition, the vapour inside the food is continuously transferred to the surface, where a much lower pressure than interior parts of the food products is expected. In this way, the water content in the food products is lowered to an acceptable level in a relatively short time without causing severe damage to the shape and the texture of the products in comparison to conventional air drying. Moreover, relatively lower processing temperature/s also help to maintain more nutrients than conventional thermal treatment.

As explained above, according to prior art, slices / whole or cut of fruits and vegetables are heated / dehydrated using infrared radiation only from the one side facing heaters. Hence, evaporation of air vapours from a lower side of the slices / whole or cut fruits and vegetables will not at all evaporate or evaporation will be low and take longer time to complete drying / dehydrating of the slices / whole or cut fruits and vegetables.

Furthermore, slices / whole or cut fruits and vegetables have to be made as thinner as possible so that complete water is removed in shortest possible time from the mass. As per our research we have observed that the thinner slice of the slices / whole or cut fruits and vegetables, lesser the crispiness. This needs to be addressed.

Additionally, if the fruits or vegetable slices / whole or cut are put on metallic plates there is no path to escape water vapours from a metallic side, of the metallic plates, which is in contact with fruits / vegetable slices / whole or cut. Because of this arrangement the time taken to dry / dehydrate fruits or vegetable slices / whole or cut increases. Also, after drying / dehydrating these slices / whole or cut fruits and vegetables stick to the metallic plates.

Still additionally, Infrared radiation lamps or heaters are installed inside the vacuum chamber; thereby, increasing costs.

There is a need to alleviate all the aforementioned problems of the prior art.

OBJECTS OF THE INVENTION:

An object of the invention is to provide a fast and inexpensive machine for a vacuum drying process, eliminating microwave radiation.

Another object of the invention is to provide a machine with an all-encompassing / omni-directional / all-around vacuum drying process such that no surface of a target object is left untreated.

Yet another object of the invention is to provide a machine for a vacuum drying process such that the target object does not stick to any surface. Still another object of the invention is to provide a machine for a vacuum drying process which does not cause severe damage to the shape and the texture of the target objects.

An additional object of the invention is to provide a machine for a vacuum drying process which maintains relatively more nutrients of target objects.

Yet an additional object of the invention is to provide a machine for a vacuum drying process which, while allowing thinness of target objects to be reduced, retains crispiness upon exposure to the process.

Still an additional object of the invention is to provide a machine for a vacuum drying process which eliminates sticking of target objects to metallic plates.

SUMMARY OF THE INVENTION:

According to this invention, there is provided a vacuum drying machine comprising: an operative top cover and an operative bottom support tray for mesh defining a vacuum chamber; one or more first infrared heaters (provided on an operative lower side of the operative top cover, in that, an operative top glass layer being provided beneath the operative top cover such that the one or more first infrared heaters are interspersed between the operative top cover and the vacuum chamber; o said heaters being placed in a matrix form such that adjacent heaters are spaced apart from each other in a pre-defined spacing pattern; and a mesh tray with metal frame configured to host target products which are to be vacuum dried, said mesh tray with metal frame being spaced apart from said operative bottom support tray for mesh, said mesh tray with metal frame sits between the operative top cover and the operative bottom support tray for mesh and is spaced apart from said operative top cover, said operative bottom support tray for mesh, as well as from their corresponding one or more first infrared heaters.

In at least an embodiment, one or more second infrared heaters provided on an operative lower side of the operative bottom support tray for mesh.

In at least an embodiment, one or more second infrared heaters provided on an operative lower side of the operative bottom support tray for mesh, said mesh tray with metal frame being spaced apart from corresponding one or more second infrared heaters.

In at least an embodiment, said mesh tray with metal frame being fitted in a vacuum chamber assembly from which it can be removed or inserted.

In at least an embodiment, said mesh tray with metal frame being fitted in a vacuum chamber assembly from which it can be removed or inserted, said vacuum chamber assembly being a box-like enclosure which a front / lateral entry slit of removal or insertion of the mesh tray with metal frame.

In at least an embodiment, a toughened glass layer forms at least the operative top and the operative bottom of the vacuum chamber assembly.

In at least an embodiment, an operative bottom glass layer being provided above the operative bottom support tray for mesh such that the one or more second infrared heaters are interspersed between the operative bottom support tray for mesh and the vacuum chamber.

In at least an embodiment, said mesh tray being provided in a metal frame as its boundary.

In at least an embodiment, a frame for fixing said mesh being provided on an operative underside of said mesh tray with metal frame to avoid sagging of said mesh tray with metal frame.

In at least an embodiment, said mesh tray with metal frame being a non-stick material mesh made of PTFE so that dried fruits and vegetables can be removed with ease.

In at least an embodiment, spaced apart distance between said heaters and said mesh tray with metal frame is in the range of 10 mm to 300 mm square shaped.

In at least an embodiment, operative vertical spaced apart distance between two adjacent heaters, in said matrix, is in the range of 5 mm to 100 mm.

In at least an embodiment, operative horizontal spaced apart distance between two adjacent heaters, in said matrix, is in the range of 10 mm to 100 mm.

In at least an embodiment, said one or more first infrared heaters face an operative bottom support tray for mesh which holds a mesh tray with metal frame over it. In at least an embodiment, said tray with mesh under the heaters being in a spaced apart manner from the heaters as well as in a spaced apart manner from the bottom support tray for mesh.

In at least an embodiment, said mesh tray with metal frame having a defined gradient so as to channelize collected water towards an outlet.

In at least an embodiment, said operative top cover and said operative bottom support tray for mesh, both, comprise a reflective surface on the side which faces the PTFE mesh tray with metal frame.

In at least an embodiment, spaced apart distance between said heaters and said mesh tray with metal frame being in the range of 5 mm to 300 mm so that the surfaces of target product is evenly heated.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:

The invention will now be described in relation to the accompanying drawings, in which:

FIGURE 1 illustrates an exploded view of the various layers of the vacuum drying machine of this invention;

FIGURE 2a illustrates the vacuum chamber assembly;

FIGURE 2b illustrates a toughened glass layer which forms at least the operative top and the operative bottom of the vacuum chamber assembly;

FIGURE 2c illustrates the mesh tray with metal frame;

FIGURE 3 illustrates one embodiment of an operative top cover with the one or more first infrared heaters;

FIGURE 4 illustrates a view showing the matrix of heaters on the operative top cover of the vacuum chamber assembly;

FIGURE 5 illustrates a view showing the heaters and the mesh tray;

FIGURE 6 illustrates the operative top cover with slots to receive heaters;

FIGURE 7 illustrates another embodiment of the mesh tray with metal frame tray;

FIGURE 8 shows an illustration which shows how the following parameters are important for even heating of fruits and / or vegetables which is not taught in prior arts; and

FIGURE 9 shows how the process (REV-dried), enabled by this invention, fares compared to prior art processes.

DETAIUED DESCRIPTION OF THE ACCOMPANYING DRAWINGS: According to this invention, there is provided a vacuum drying machine.

FIGURE 1 illustrates an exploded view of the various layers of the vacuum drying machine of this invention.

In at least an embodiment, the machine comprises an enclosure with an operative top cover (12) and an operative bottom support tray for mesh (14).

In at least an embodiment, one or more first infrared heaters (12a) are provided on an operative lower side of the operative top cover (12) and one or more second infrared heaters (14a) are provided on an operative lower side of the operative bottom support tray for mesh (14).

In at least an embodiment, the machine comprises a mesh tray with metal frame (20) configured to host target objects / products such as fruits / vegetables, either whole or sliced; which are to be vacuum dried. The mesh tray (20) sits between the operative top cover (12) and the operative bottom support tray for mesh (14) and is spaced apart from them as well as from their corresponding one or more first infrared heaters (12a) and one or more second infrared heaters (12b). Typically, the mesh tray (20) is fitted in a vacuum chamber assembly (25) from which it can be removed or inserted. Typically, this vacuum chamber assembly (25) is a box-like enclosure which a front / lateral entry slit (25a) of removal or insertion of the mesh tray (20).

FIGURE 2a illustrates the vacuum chamber assembly (25).

FIGURE 2b illustrates a toughened glass layer (25f) which forms at least the operative top and the operative bottom of the vacuum chamber assembly (25).

Reference numeral 25b shows a vacuum port.

Reference numeral 25c shows a support for receiving / fixing the toughened glass layer on the operative top.

Reference numeral 25d shows a support for receiving / fixing the toughened glass layer on the operative bottom.

Reference numeral 25e shows a thermocouple port for sensors.

In preferred embodiments, the vacuum chamber assembly’s (25) operative top wall and operative lower wall can be made of transparent material like glass, toughened glass, polycarbonate, or any other polymer.

In at least an embodiment, the machine comprises an operative top glass layer beneath the operative top cover (12) such that the one or more first infrared heaters (12a) are interspersed between the operative top cover (12) and the vacuum assembly (25) and such that the one or more second infrared heaters (12b) are interspersed between the operative bottom support tray for mesh (14).

FIGURE 2c illustrates the mesh tray with metal frame (20).

FIGURE 4 illustrates a view showing the matrix of heaters on the operative top cover of the vacuum chamber assembly.

FIGURE 5 illustrates a view showing the heaters and the mesh tray.

FIGURE 7 illustrates another embodiment of the mesh tray with metal frame tray (20).

In at least an embodiment, the mesh tray with metal frame (20) is provided in a metal frame (20a) as its boundary. A supporting grill (20b) may be provided on the operative underside of the mesh tray with metal frame (20) to avoid sagging of the mesh (20C). There is also an arrangement (20d) for pushing or pulling out the tray from the vacuum chamber assembly (25)

In preferred embodiments, the mesh of the mesh tray (20) may range, in dimensions, from 1x1 mm to 10x10 mm.

In at least an embodiment, the mesh tray with metal frame (20) is spaced apart from the bottom support tray for mesh (14). In preferred embodiments, this mesh tray with metal frame (20) can be a non-stick material mesh made of PTFE so that dried fruits and vegetables can be removed with ease. Due to this arrangement of mesh tray with metal frame (20) in conjunction with spaced apart bottom cover, the following advantages are achieved:

Heating from both sides; Evaporation from both sides, properly, similarly;

Allows for bigger thickness of food item; this makes the food item crispier.

In alternative embodiments, this mesh tray with metal frame (20) can be a nonstick material mesh which is inserted in a vacuum chamber made of transparent material like glass or any other transparent material.

FIGURE 3 illustrates one embodiment of an operative top cover (12) with the one or more first infrared heaters (12a). FIGURE 3 can also be read as the operative bottom support tray for mesh (14) with the one or more first infrared heaters (12b).

FIGURE 8 shows an illustration which shows how the following parameters are important for even heating of fruits and / or vegetables which is not taught in prior arts.

Optimum radiation distance is where red continuous and dashed lines are crossing.

Typically, in order to achieve substantially advantageous results, spaced apart distance between heaters and support tray for mesh is in the range of 5 mm to 300 square shaped.

In at least an embodiment, the heaters are spaced apart from each other in a predefined manner. The heaters (12a), are thus placed that they form a matrix.

Typically, in order to achieve substantially advantageous results, operative vertical spaced apart distance between two adjacent heaters is in the range of 10 mm to 100 mm. Typically, in order to achieve substantially advantageous results, operative horizontal spaced apart distance between two adjacent heaters is in the range of 10 mm to 100 mm.

Because of this arrangement, even, comprehensive 360 degree heating is achieved. Technical advantages are:

- This avoids caramelization of fruit (which could happen due to sugars in fruit);

- Even evaporation of water from fruit / vegetable; because of even evaporation, the fruit / vegetable can be rehydrated to its original form in exact same manner.

- Tissues do not break down in this invention; because of no tissue damage the fruit / vegetable can be rehydrated to its original form in exact same manner.

As opposed to this process, prior arts teach a freeze-drying process where tissues break down; once broken down, these tissues cannot be rebuilt again.

Preferably, slice size of fruit is to be between 2 mm and 15 mm.

Preferably, drying time for even drying and crispiness 2 hours to 15 hours.

In prior arts of dehydrating processes sugar in the water comes out of the fruits and vegetables with water in the fruits, spreads on the tray and it sticks to the PTFE (Polytetrafluoroethylene) cloth pasted on fruit drying trays and it becomes difficult to remove the dehydrated fruits from the drying trays. This problem has been minimized, in this invention, by arranging fruits and vegetable slices on the mesh tray (20) of nonstick material like PTFE (Polytetrafluoroethylene) for ease of removing fruits and vegetables from the resting support after dehydrating as the contact between fruits and vegetable is minimized.

While fresh fruits and vegetables are in process of dehydration the water from the fruits and vegetables flows out. This water can increase water vapour load resulting in increasing drying time. The gradient-based design with spaced apart distance between mesh tray with metal frame (20) and bottom support tray for mesh (14) is designed, in this invention, so that this excess water flows out in the container. =

In at least an embodiment, the current invention provides excessive water vapours removal by purging dry air. Any vacuum pump has certain water vapours handling capacity. When installed vacuum pump cannot handle excessive water vapours accumulated in the vacuum chamber during drying process, which delays the drying time. In such case a dry air is purged for 1 second to 5 minutes during evacuation and drying process. The dry air increases the pressure inside the vacuum chamber and pushes water vapours towards vacuum pump. This dry air purging reduces drying time effected due to increase in water vapours in vacuum chamber. . -

One or more first infrared heaters (12a) facing an operative bottom support tray for mesh (14) which holds a mesh tray with metal frame (20) over it. The mesh tray with metal frame (20) is configured to hold fruits and vegetables under the heaters (12a) in a spaced apart manner from the heaters (12a) as well as in a spaced apart manner from the bottom support tray for mesh (14). This allows appropriate dehydration. Water that flows out dehydrated fruit / vegetable is collected below the mesh tray with metal frame (20); an appropriate gradient (14b) is provided so as to channelize collected water towards an outlet (14c).

In one of the alternative embodiments, the operative top cover (12) and the operative bottom support tray for mesh (14), both, comprise a reflective surface (19) on the side which faces the mesh tray with metal frame (20). This is the side on which the one or more heaters (12a, 14a) are installed facing the mesh tray. Preferably, the reflective surface (19) is a stainless mirror finished reflective surface (19a).

In preferred embodiments, infrared radiant heaters of short / near or long / far wavelength are installed on operative top and / or operative bottom, outside of the vacuum chamber assembly and the distance of 5 mm to 300 mm so that the surfaces of slices / whole or cut fruits and vegetables are evenly heated.

FIGURE 6 illustrates the operative top cover with slots (12b) to receive heaters (12a). This top cover is an IR heater (12a) mounting tray cum reflector.

In at least an embodiment, temperature sensors are installed on all four sides of nonstick mesh to monitor and control the heating temperature.

Using the similar art of vacuum chamber, the solar rays can also be used to dry / dehydrate slices / whole or cut fruits and vegetables.

Thus, due to the construction, logic, and working, of the current invention’s machine, slices / whole or cut fruits and vegetables are heated from both (operative top and operative bottom) sides using infrared radiation from “near infrared to far infrared”. This solves the problem of: Radiant dehydration, water content, texture, maintain more nutrients

Thus, due to the construction, logic, and working, of the current invention’s machine, as the slices / whole or cut of fruits and vegetables are heated / dehydrated from both (operative top and operative bottom) the sides using infrared radiation of any length, water vapour escapes from both (operative top and operative bottom) the sides resulting shorter and half the time to dry / dehydrate fruits and vegetables and the slices / whole or cut fruits and vegetables have lesser crispness.

This solves the problem of crispiness versus thinness.

Thus, due to the construction, logic, and working, of the current invention’s machine, the slices / whole or cut fruits and vegetables are put on any type of nonstick cloth pasted on metallic plate or the plate is replaced with a mesh of nonstick material like PTFE (Polytetrafluoroethylene), silicone, or any other nonstick material having mesh size from 1.00 mm to 30 mm square. As the mesh of nonstick material uses the slices / whole or cut fruits and vegetables can be heated and dried / dehydrated from both the sides. Due to this arrangement drying / dehydrating process is performed in shortest time.

This solves the problem of cost of drying as well as of sticking of product to plate.

Thus, due to the construction, logic, and working, of the current invention’s machine, the infrared heaters are installed outside of the vacuum chamber assembly i.e., at the top and bottom, hence the volume of the chamber drastically reduces, and ultimately extremely low-capacity vacuum pump is required. This solves the problem of capital cost.

TECHNICAL ADVANTAGES:

1. As the fruits and vegetables are highly perishable; those can be passed through the mentioned process and loss of harvested good product can be eliminated;

2. Energy efficient model, reduction in eventual carbon footprint;

3. The machine can be installed at the farm’s locations;

4. Processing does not require any preservative chemical so free from any artificial ingredients and 100% original and natural;

5. As the dehydration / drying of fruits and vegetables is done between 30° C to 110° C and under low pressure of less or more than 1.00 mm Hg loss of nutrients and texture is minimum;

6. Even loss of Vitamin C, Carotene, Phenolic compounds, and other vitamin is also low;

7. Also, on the other hand, the fruits and vegetables become crispy, and taste is enhanced as the total water content is removed from the fruits and vegetables;

8. It mainly aims at extending the product and/or its constituent’ s shelf life by preventing the growth of microorganisms;

9. As the machine will be installed at the orchids and farms employments; it will be available for grass root level manpower particularly women;

10. As the machine will be installed at the orchids and farms sites weight and volume reduction will be reduced by 80 to 90%. Hence the cost of transportation of end product will be reduced proportionately. Which is considerably high; 11.All types of fruits are not available at all locations of the world due to geological and atmospheric conditions. But because of this device any fruit will be available at any corner of the world without any loss of nutrients, texture and taste that too throughout the year;

12. Machine is equipped with programmed process parameters so that the user has to select the name of the fruit or vegetable to be dried/dehydrated. It will also have GPRS like suitable software for tracking and maintenance of the device; Machine can be operated with energy source of complete Electricity, Temperature controlled Solar only for heating and vacuum pump with solar generated electricity, compressed Biogas generated electricity, with any type of gas fired infrared heaters like biogas or electricity generated using biogas.

The TECHNICAL ADVANCEMENT of this invention lies in providing a vacuum drying machine which has specific layers, provides a special mesh tray in a vacuum chamber assembly with toughened glass and irradiated with one or more heaters from an operative top side and an operative bottom side - all targeted towards the mesh tray.

While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Claims

CLAIMS,

1. A vacuum drying machine comprising:

- an operative top cover (12) and an operative bottom support tray (14) for mesh (20C) defining a vacuum chamber (25);

- one or more first infrared heaters (12a) provided on an operative lower side of the operative top cover (12), in that, an operative top glass layer being provided beneath the operative top cover (12) such that the one or more first infrared heaters (12a) are interspersed between the operative top cover (12) and the vacuum chamber (25); o said heaters (12a) being placed in a matrix form such that adjacent heaters are spaced apart from each other in a pre-defined spacing pattern; and

- a mesh tray (20) with metal frame configured to host target products which are to be vacuum dried, said mesh tray with metal frame (20) being spaced apart from said operative bottom support tray for mesh (14), said mesh tray with metal frame (20) sits between the operative top cover (12) and the operative bottom support tray (14) for mesh (20C) and is spaced apart from said operative top cover (12), said operative bottom support tray (14) for mesh (20C), as well as from their corresponding one or more first infrared heaters (12a).

2. The machine as claimed in claim 1 wherein, one or more second infrared heaters (14a) provided on an operative lower side of the operative bottom support tray (14) for mesh (20C).

3. The machine as claimed in claim 1 wherein, one or more second infrared heaters (14a) provided on an operative lower side of the operative bottom support tray (14) for mesh (20C), said mesh tray (20) with metal frame being spaced apart from corresponding one or more second infrared heaters (14a). The machine as claimed in claim 1 wherein, said mesh tray (20) with metal frame being fitted in a vacuum chamber assembly (25) from which it can be removed or inserted. The machine as claimed in claim 1 wherein, said mesh tray (20) with metal frame being fitted in a vacuum chamber assembly (25) from which it can be removed or inserted, said vacuum chamber assembly (25) being a boxlike enclosure which a front / lateral entry slit (25a) of removal or insertion of the mesh tray (20) with metal frame t. The machine as claimed in claim 1 wherein, a toughened glass layer (25f) forms at least the operative top and the operative bottom of the vacuum chamber assembly (25). The machine as claimed in claim 1 wherein, an operative bottom glass layer being provided above the operative bottom support tray (14) for mesh (20) such that the one or more second infrared heaters (14a) are interspersed between the operative bottom support tray for mesh (14) and the vacuum chamber (25). The machine as claimed in claim 1 wherein, said mesh tray (20) being provided in a metal frame (20a) as its boundary. The machine as claimed in claim 1 wherein, a frame (20b) for fixing said mesh (20C) being provided on an operative underside of said mesh tray (20) with metal frame to avoid sagging of said mesh tray (20) with metal frame. The machine as claimed in claim 1 wherein, said mesh tray (20) with metal frame being a non-stick material mesh made of PTFE so that dried fruits and vegetables can be removed with ease. The machine as claimed in claim 1 wherein, spaced apart distance between said heaters (12a) and said mesh tray (20) with metal frame is in the range of 10 mm to 300 mm square shaped. The machine as claimed in claim 1 wherein, operative vertical spaced apart distance between two adjacent heaters, in said matrix, is in the range of 5 mm to 100 mm. The machine as claimed in claim 1 wherein, operative horizontal spaced apart distance between two adjacent heaters, in said matrix, is in the range of 10 mm to 100 mm. The machine as claimed in claim 1 wherein, said one or more first infrared heaters (12a) face an operative bottom support tray (14) for mesh (20) which holds a mesh tray (20) with metal frame over it. The machine as claimed in claim 1 wherein, said tray with mesh (20C) under the heaters (12a) being in a spaced apart manner from the heaters (12a) as well as in a spaced apart manner from the bottom support tray (14) for mesh (20C). The machine as claimed in claim 1 wherein, said mesh tray (20) with metal frame_(20) having a defined gradient (14b) so as to channelize collected water towards an outlet (14c). The machine as claimed in claim 1 wherein, said operative top cover (12) and said operative bottom support tray (14) for mesh (20C), both, comprise a reflective surface (19) on the side which faces the PTFE mesh tray (20) with metal frame. The machine as claimed in claim 1 wherein, spaced apart distance between said heaters and said mesh tray (20) with metal frame being in the range of 5 mm to 300 mm so that the surfaces of target product is evenly heated.