KR20170119265A - Food dryer with ceramic heater - Google Patents

Abstract

A food dryer having a ceramic heater is disclosed. The disclosed food drier includes a housing having an inner space formed therein, a hot air generating unit generating hot and dry hot air to be introduced into the inner space, and a plurality of dry areas arranged in the inner space, And a sidewall of the sidewall has a plurality of nozzle openings for discharging the hot air introduced into the plurality of drying areas to the sidewall. A drying object is disposed in a plurality of drying regions, and the drying object is dried by hot air discharged from a plurality of nozzle holes. The hot air generating unit generates electric heat by converting electrical energy into heat and has a ceramic heater having an outer wall and a lattice inner wall extending in a lattice pattern in cross section in the outer wall. Air introduced into the inside of the housing passes through the heat exchange passage between the inner walls of the lattice, heat-exchanges, and is discharged as hot air into the inner space.

Description

[0001] The present invention relates to a food dryer having a ceramic heater,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food drier, and more particularly to a food drier for blowing hot air to dry food.

The food dryer blows hot and dry air to dry the food to be dried. The food drier includes a case having an internal space opened and closed by a door and a heater and a fan for blowing hot air into the case.

A heater provided in a food dryer for drying food with hot air is usually made of metal or PT C material. However, it is difficult to quickly and precisely control the temperature of the heater made of these materials, and it is difficult to design the shape so that the surface area in contact with the air blown by the fan is widened. In some cases, a heat sink may be required. Therefore, energy transfer efficiency is lowered, energy consumption is large, and it is vulnerable to corrosion, resulting in poor durability and deterioration of drying quality.

To solve this problem, a silicon carbide (SiC) non-oxide ceramic heater can be applied. Silicon carbide non-oxide ceramic heaters are widely used as heater materials because of their excellent heat resistance and thermal conductivity. However, the silicon carbide has a low water resistance and is easily deteriorated upon contact with moisture, thereby losing its function as a heater. Further, in the case of silicon carbide, there is a problem that a separate control device is necessary because the resistance varies with temperature, and a resistance is too low to be used as a heater, so that atmospheric electricity can not be used.

In addition, the conventional food drier is configured such that hot air flows only through one point in the inner side wall of the housing defining the inner space in which the food to be dried is placed. Therefore, even in the inner space, there is a large variation in the drying quality depending on the position where the drying object is disposed. That is, depending on whether the object to be dried is located on the upper side, the lower side, the left side, or the right side in the inner space, it may not be sufficiently dried.

Korean Registered Patent No. 10-1283516

Provided is a food drier having a ceramic heater which is excellent in thermal conductivity, corrosion resistance, thermal shock resistance and rigidity, capable of controlling temperature quickly and precisely, and improved in drying quality, than a heater made of a metal material or a PTC material .

Further, the present invention provides a food drier having a ceramic heater having an appropriate resistance value so that energy efficiency is improved and a transformer is not required.

The present invention also provides a food drier having a ceramic heater with a large surface area in contact with air to be blown while minimizing air blowing pressure drop.

The present invention also provides a food drier capable of obtaining a uniform drying quality with less variation in drying quality depending on the position where the object to be dried is placed.

The present invention also provides a food dryer in which the transfer of odor is suppressed even when different types of dried objects are dried together to improve the drying quality.

According to the present invention, there is provided an air conditioner comprising: a housing having an inner space formed therein; a hot air generating unit generating hot and dry hot air to be introduced into the inner space; And a plurality of nozzle openings formed in the side walls for discharging the hot air introduced into the plurality of drying areas to the plurality of drying areas, The object to be dried is disposed in a plurality of drying regions and the object to be dried is dried by hot air discharged from the plurality of nozzle through holes, and the hot air generating unit generates heat by converting electric energy into heat, And a ceramic heater having a lattice inner wall extending in a lattice pattern in cross section The air flowing into the housing passes through a heat exchange channel between the inner walls of the lattice, heat-exchanges and is discharged into the inner space as hot air. The ceramic heater is formed by sintering the composition of the ceramic heater Wherein the composition of the ceramic heater includes at least one of aluminum nitride (AlN) and silicon nitride (Si ₃ N ₄ ), wherein the ceramic and metal mixed powder includes a ceramic and metal mixed powder, a dispersant and a binder. A non-oxide ceramic powder occupying 80 to 95% by weight of the total weight of the ceramic and metal mixed powder, and a metal powder occupying 5 to 20% by weight of the total weight of the ceramic and metal mixed powder, Thereby providing a food dryer.

The ceramic heater provided in the food drier of the present invention is excellent in heat resistance, corrosion resistance, strength, and thermal shock resistance, including non-oxide ceramics as a main material and metal as a material, and is easy to produce with appropriate resistance. A food dryer can be used by supplying atmospheric electricity.

The ceramic heater provided in the food drier of the present invention is formed of a so-called honeycomb structure having a lattice inner wall that minimizes a decrease in blowing pressure and widens a heat exchange surface area with air blown, Or a PTC heater (positive temperature coefficient heater), the energy transfer efficiency and drying quality are improved, and rapid and precise temperature control is possible.

Further, the ceramic heater provided in the food drier of the present invention emits far-infrared rays to improve the effect of sterilizing and deodorizing the object to be dried, preventing nutrition damage when the object to be dried is food, do.

According to a preferred embodiment of the present invention in which the catalyst is applied to the surface of the inner wall of the lattice of the ceramic heater, the catalyst decomposes harmful components and odor components emitted from the dried object to improve the drying quality.

Further, according to the food dryer of the present invention, when hot air is blown into the inner space in which the drying object is placed, hot air flows into the inner space through a plurality of nozzles arranged in a uniform manner rather than only through one point . Accordingly, the deviation of the drying quality according to the position where the drying object is disposed is small, and uniform drying quality can be obtained. Even when a small amount of energy is applied, all the dried objects filled in the inner space can be uniformly dried, thereby reducing energy consumption.

According to the food drier of the present invention, the inner space in which the object to be dried is placed is separated into the plurality of dry areas by the hot air discharge partition, and the dry objects disposed in the respective dry areas are independently . Therefore, even if different types of dried objects are dried at the same time, they can be disposed in different drying zones to prevent the transfer of odor and improve the drying quality. Particularly, it is useful when the object to be dried having odor and the object to be dried having no odor are put together in a food dryer and dried.

1 is a perspective view illustrating a food drier according to a first embodiment of the present invention.
Figs. 2, 3 and 4 are cross-sectional views cut along Fig. 1 in accordance with II-II, III-III, and VI-VI.
5 is a perspective view showing a ceramic heater in the hot air generating unit of FIG. 2. FIG.
6 is a view showing the microstructure of the ceramic heater of FIG.
7 is a perspective view illustrating a food drier according to a second embodiment of the present invention.
Figs. 8, 9 and 10 are cross-sectional views taken along line VIII-VIII, IX-IX, and XX of Fig.

Hereinafter, a food drier having a ceramic heater according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The terminology used herein is a term used to properly express the preferred embodiment of the present invention, which may vary depending on the intention of the user or operator or the custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification.

FIG. 1 is a perspective view showing a food drier according to a first embodiment of the present invention, and FIGS. 2, 3 and 4 are cross-sectional views taken along line II-II, III-III and VI- Sectional view. Referring to FIGS. 1 to 4, the food dryer 10 according to the first embodiment of the present invention is for rapidly drying food, and includes a dryer housing 11, a hot air discharge partition 30, And a hot air generating unit 120.

The dryer housing 11 includes a top plate 12, a bottom plate 13, a right plate 14, a left plate 15, and a bottom plate 12, which are formed in a hexahedron shape so as to form an opened inner space 20 And a back plate (16). A pair of front doors 23 and 25 are hinged to the front and left front ends of the dryer housing 11 so that the interior space 20 ).

The hot air generating unit 120 generates hot and dry hot air to be introduced into the internal space 20. [ The hot air generating unit 120 is fixedly arranged in the rear upper side of the inside of the dryer housing 11 so that the air outside the dryer housing 11 flows into the hot air generating unit 120, An opening 17 is formed. However, the position where the hot air generating unit 120 is installed in the dryer housing 11 and the position where the air inlet opening 17 is formed are not limited to the embodiment shown in FIG. 2, As shown in FIG.

The hot air discharge partition 30 is disposed in the inner space 20 to divide the inner space 20 into a right dry area 18 and a left dry area 19. [ The hot air discharge partition 30 has a pair of side walls 34 spaced from each other, and the front end of the hot air discharge partition 30 is closed and the rear end thereof is opened. Accordingly, the inside of the hot air discharge partition 30 is empty so that air can flow, and becomes a flow path through which hot air flows.

The rear end of the opened hot air discharge partition 30 is connected to the rear duct 27 for guiding the hot air generated by the hot air generating unit 120 to flow upward and downward. In such a configuration, a flow path through which hot air flows from the rear duct 27 to the hot air discharge partition 30 is formed in the dryer housing 11, and the inside of the hot air discharge partition 30 The hot air flowing into the flow path can freely flow up and down.

A plurality of nozzle openings (36) are formed on both side walls (34) of the hot air discharge partition (30). The plurality of nozzle through holes (36) are evenly distributed. The external air flows through the hot air generating unit 120 and becomes hot air. The hot air flows into the hot air discharge partition 30 through the rear duct 27 and the plurality of nozzle holes 36, To the right side drying area 18 and the left side drying area 19. [ Accordingly, the object to be dried (not shown) disposed in the right and left dry regions 18, 19 is dried by hot air discharged from the plurality of nozzle holes 36.

A plurality of trays 43 are independently disposed above and below the drying zone 18 and the left drying zone 19 and the drying object is placed on the tray 43. For example, a drying object such as a food or tableware can be placed on the tray 43 and dried. A mesh 45 is formed in the tray 43 so that hot air can flow through the tray 43 and up and down. Accordingly, the drying object placed on the tray 43 is heated by the hot air from all directions as well as the direction facing the nozzle through-hole 36, so that the drying time is shortened and all portions of the drying object can be evenly dried.

A tray support 41 is fixedly installed on the right inner side surface and the left inner side surface of the inner side surface defining the inner space 20 of the dryer housing 11 and the both side walls 34 of the hot air discharge partition 30 (42) is fixedly installed. The trailing edges of the trays 43 disposed on the right and left dry areas 18 and 19 are supported by the tray supports 41 and 42 so that the tray 43 can be stably . The tray 43 can be easily attached to and detached from the inner space 20 through the front surface of the opened dryer housing 11 by opening the pair of front doors 23 and 25. [

The food dryer 10 is configured such that the internal space in which the object to be dried is placed is divided into a plurality of dry areas 18 and 19 by the hot air discharge partition 30 and the dried objects placed in the respective dry areas 18 and 19 And is heated and dried independently by the hot air discharged from the plurality of nozzle through holes (36). Therefore, even if different types of dried objects are dried at the same time, they can be prevented from transferring odor by arranging them in different dry regions 18 and 19, and the drying quality is improved. On the other hand, the user may arrange a drying object of the same kind in a plurality of drying zones 18 and 19 to proceed the drying operation.

The hot air generating unit 120 includes a ceramic heater 125 that generates heat by converting electric energy into heat and a fan 125 that is disposed behind the ceramic heater 125 and blows the heat emitted from the ceramic heater 125 forward and a fan (121). The fan 121 is installed in the dryer housing 11 so as to be aligned with the air inlet opening 17 of the dryer housing 11.

In the food dryer (10) of the present invention, the hot air discharge partition (30) is not necessarily arranged to separate the center of the inner space (20), but may be arranged to be deflected to one side. There is no need to provide only one hot air discharge partition, and two or three hot air outlet compartments may be provided to divide the internal space of the food dryer into three or four drying areas. Furthermore, not only one hot air generating unit but also two or three hot air generating units may be provided.

FIG. 5 is a perspective view showing a ceramic heater in the hot air generating unit of FIG. 2, and FIG. 6 is a view showing a fine structure of the ceramic heater of FIG. 2, 5, and 6, the ceramic heater 125 generates heat by converting electric energy into heat. The ceramic heater 125 includes a pipe-shaped outer wall 126, And a lattice inner wall 128 extending to be a lattice pattern. The front surface and the back surface of the pipe-shaped outer wall 126 are not clogged. A heat exchange channel 129 is formed in the outer wall 126 to allow air to flow back and forth through the ceramic heater 125 through the space between the inner walls 128 of the lattice.

The heat exchanging efficiency between the ceramic heater 125 and the air passing through the ceramic heater 125 is greatly improved since the contact surface area where the air passing through the heat exchanging flow path 129 is in contact with the inner wall 128 of the lattice greatly increases. The air blown by the fan 121 flows in from the rear of the ceramic heater 125 along the direction of the arrow in FIG. 5 and passes through the heat exchange channel 129 between the inner walls 128 of the lattice to perform heat exchange, And the hot air is discharged to the front of the ceramic heater 125 by the blowing pressure of the fan.

The outer wall 126 of the ceramic heater 125 and the lattice inner wall 128 are integrally formed and are made of a powdery non-oxide ceramic material as a main material and a sintered (sintered) .

In addition, the composition of the ceramic heater 125 includes ceramic and metal mixed powders, a dispersant, and a binder. The ceramic and metal mixed powder includes a non-oxide ceramic powder and a metal powder. The non-oxide ceramic powder is composed of non-oxide ceramics. The non-oxide ceramics is composed of a combination of a metal element (Si, Ti, Al, Zr, etc.) with an element such as carbon (C), nitrogen (N), or boron (B) in a carbide, a nitride or a boride ceramic. In this case, the non-oxide based ceramic powder includes at least one of aluminum nitride (AlN), silicon carbide (SiC), and silicon nitride (Si ₃ N ₄ ).

Aluminum nitride is excellent in thermal conductivity. Accordingly, it is possible to manufacture a heater using the aluminum nitride as a main material, and to produce a heater with high efficiency. Silicon carbide has characteristics such as excellent corrosion resistance, thermal shock resistance and thermal conductivity, and thus it is possible to manufacture a heater excellent in corrosion resistance by manufacturing the heater with silicon carbide. Silicon nitride is excellent in heat resistance, strength and thermal shock resistance. When the heater is made of silicon nitride, a heater having excellent durability can be manufactured.

According to the present invention, only aluminum nitride can be used as a non-oxide ceramic powder material. Alternatively, silicon nitride can be used as a non-oxide ceramic powder material. Alternatively, aluminum oxide and silicon nitride may be mixed together to form a non-oxide based ceramic powder.

The non-oxide ceramic powder has a resistance of about 10 < ^{7 >} OMEGA, which is too high for the heater to function. Therefore, in the present invention, the non-oxide ceramic powder is mixed with a metal powder. The metal powder is mixed with the non-oxide based ceramic powder so that the ceramic heater has a resistance of 10 < ^-1 > to 10 < ³ > In this case, the metal powder may include at least one selected from aluminum (Al), copper (Cu), and nickel (Ni).

In this case, the non-oxide ceramic powder preferably has an average particle diameter of 1 to 50 탆, and in this case, the average particle diameter of the metal powder is preferably 50 to 300 nm. When the average particle diameter of the non-oxide ceramic powder is less than 1 占 퐉, the kneading property with the metal powder is deteriorated, and when the average particle diameter of the non-oxide ceramic powder exceeds 50 占 퐉, It is difficult to do. In this case, when the average particle diameter of the metal powder is less than 50 nm, it is difficult to connect the non-oxide particles to each other with conductivity, and when the average particle diameter of the metal powder exceeds 300 nm, It can not be mixed with the cargo-based ceramic powder.

The metal powder and the non-oxide ceramic powder may be mixed in water for 5 to 15 hours to obtain a slurry state. In this case, it further includes a dispersant and a binder. The dispersant allows the non-oxide ceramic powder and the metal powder to be dispersed well. As the dispersing agent, at least one of fatty acid-based materials having a polymer shape can be used. In this case, it is preferable that the dispersant has 3 to 30 parts by weight relative to 100 parts by weight of the mixed powder of ceramic and metal.

The binder functions to bond the metal powder and the non-oxide ceramic powder. As the binder, polyvinyl alcohol (PVA), polyvinyl carbonate (PVC), or the like can be used. In this case, the binder preferably has a weight of 2 to 30 parts by weight based on 100 parts by weight of the mixed ceramic and metal powder.

On the other hand, it is preferable to further include methyl cellulose as an additive. The methylcellulose functions to improve the molding performance in the process of extrusion molding in the form of a pipe having a plurality of passages. In this case, it is preferable that the methyl cellulose has 2 to 30 parts by weight relative to 100 parts by weight of the mixed ceramic and metal powder. When the content of methyl cellulose is less than 2 parts by weight, extrusion molding is not performed properly. When the content of methyl cellulose exceeds 30 parts by weight, mold retention becomes difficult in the post-molding step.

The metal powder may further include silicon. The non-oxide ceramic powder may further include silicon carbide (SiC). The silicon carbide is excellent in electrical conductivity. Therefore, when mixed with at least one of the insulating aluminum nitride (AlN) and silicon nitride (Si ₃ N ₄ ), it becomes possible to have appropriate electrical conductivity.

As shown in FIG. 5, when the slurry is extruded and dried, an external shape of the ceramic heater 125 is formed, and the ceramic heater 125 may be formed by sintering at a high temperature of 1400 ° C. or higher and performing heat treatment. The heat treatment is a process of heating the ceramic heater 125 to a temperature lower than the sintering temperature, so that the hardness of the ceramic heater 125 can be enhanced due to the heat treatment.

In this case, as shown in FIG. 6, a metal powder (ME) component is interposed between the non-oxide based ceramic powder (CE) components so that the ceramic heater 125 can be energized. The resistance value of the ceramic heater 125 can be changed by changing the weight percentage of the metal powder (ME) component.

Since the ceramic heater 125 having the heat exchange surface area greatly expanded by extrusion molding and sintering is formed, the installation area can be made smaller than the heater of the metal material, the manufacturing cost is reduced, and the energy efficiency is also improved. The outer wall 126 of the ceramic heater 125 shown in FIG. 5 may be in the form of a pipe having a circular cross section, but not limited thereto. For example, the outer wall 126 may have a polygonal pipe shape such as a triangular or rectangular cross section.

As shown in an enlarged cross-sectional view in FIG. 5, a catalyst 131 is applied to the outer surface of the inner lattice wall 128. Although not shown in FIG. 5, a catalyst 131 may be applied to the outer surface of the outer wall 126. The catalyst 131 may be applied to the ceramic heater 125 by spraying the liquid catalyst 131 or by dipping the ceramic heater 125 on the liquid catalyst 131 and drying . For example, the catalyst 131 may be a platinum (Pt) or palladium (Pd) catalyst.

The catalyst 131 promotes a decomposition reaction for decomposing at least one component contained in the air in the internal space. In addition, incomplete combustion substances such as carbon monoxide, hydrocarbons, and the like may be emitted from the object to be dried, and the catalyst 131 may accelerate the decomposition of the incomplete combustion materials and odor substances. As a result, the drying quality of the dried object can be further improved.

The ceramic heater 125 is made of a so-called honeycomb type ceramic material having a non-oxide ceramic (CE) as a main material and having a lattice inner wall 128 for minimizing a decrease in the blowing pressure and widening a surface area of heat exchange with air to be blown. Structure. Therefore, energy efficiency and drying quality are improved, and quick and precise temperature control is possible, as compared with a dryer using a metal material heater or a PTC heater (positive temperature coefficient heater). In addition, the ceramic heater 125 emits far-infrared rays, thereby improving the sterilizing and deodorizing effect of the object to be dried. In the case where the object to be dried is a food, it prevents nutrition damage and maintains the drawing for a long time.

When a ceramic heater having a plurality of passages is manufactured by using the composition of the ceramic heater described above, it is excellent in corrosion resistance against acid, alkali, moisture and the like, and can be heated by direct contact with the object to be heated. Further, it is possible to coat the ceramic heater with a catalyst such as metal or metal oxide.

The coated catalyst has a characteristic of maximizing the activity at a temperature higher than a certain temperature when the heating body is heated, and thus has a performance suitable for decomposition of a specific component. That is, it is possible to decompose and remove specific components using a catalytic reaction as well as a function of heating a fluid passing through a plurality of passages.

FIG. 7 is a perspective view showing a food drier according to a second embodiment of the present invention, and FIGS. 8, 9, and 10 are cross-sectional views cut along the lines VIII-VIII, IX-IX, and XX of FIG. 7 . 7 to 10, among the components provided in the food drier 10B according to the second embodiment of the present invention, the same components as the components of the food drier 10 according to the first embodiment of the present invention are the same Reference numerals are given, and duplicate descriptions may be omitted below.

Referring to FIGS. 7 to 10, the food drier 10B according to the second embodiment of the present invention is for rapidly drying objects to be dried such as foods, tableware, clothes, etc., and includes a housing 11, A hot air discharge partition 30B, and a hot air generating unit 120. [

The housing 11 has a hexahedral shape and includes an upper plate 12, a lower plate 13, a right plate 14, a left plate 15, and a rear plate 12, which are corners so as to form an internal space 20 with a front face open. And a plate (16). A pair of front doors 23 and 25 are hinge-connected to the right front end and the left front end of the housing 11 to hinge the inside space 20 through the front surface of the housing 11. [ Open and close.

The hot air generating unit 120 generates hot and dry hot air to be introduced into the internal space 20. [ The hot air generating unit 120 is fixedly arranged at the rear upper side inside the housing 11 and the air inlet opening (not shown) is formed in the rear plate 16 so that air outside the housing 11 flows into the hot air generating unit 120 17 are formed. However, the position where the hot air generating unit 120 is installed in the housing 11 and the position where the air inlet opening 17 is formed are not limited to the embodiment shown in FIG. 8, It is only an example.

The hot air discharge partition 30B is disposed in the inner space 20 to divide the inner space 20 into a right dry region 18 and a left dry region 19. [ The hot air discharge partition 30B has a plurality of hot air ducts 31 extending from the rear to the rear and arranged in a line up and down. Each of the hot air ducts 31 has a top wall 32, a bottom wall 33, and a pair of side walls 34, which have a rectangular cross section and are hollowed to allow air to flow. The front end of the hot air duct 31 is closed and the rear end thereof is opened.

The rear end of the opened hot air duct 31 is connected to the rear duct 27 for guiding the hot air generated by the hot air generating unit 120 to flow in a vertical direction. With this configuration, a flow path is formed in the housing 11 in which hot air flows from the rear duct 27 to the plurality of hot air ducts 31.

A plurality of nozzle openings (36) are formed on both side walls (34) of the plurality of hot air ducts (31). The plurality of nozzle holes 36 are evenly distributed in the longitudinal direction of the hot air duct 31. The hot air flows into the plurality of hot air ducts 31 through the rear duct 27 and flows through the plurality of nozzle through holes 36. The hot air flows into the plurality of hot air ducts 31 through the rear ducts 27, To the right side drying area 18 and the left side drying area 19. [ Accordingly, the object to be dried (not shown) disposed in the right and left dry regions 18, 19 is dried by hot air discharged from the plurality of nozzle holes 36.

A plurality of trays 43B are arranged on the right and left dry areas 18 and 19 so as to be spaced apart from each other and the drying object is placed on the tray 43B and dried. A mesh 45 is formed in the tray 43B so that hot air can flow up and down through the tray 43B. Accordingly, the drying object placed on the tray 43B is heated by the hot air from all directions as well as the direction facing the nozzle through-hole 36, so that the drying time is shortened and all portions of the drying object can be evenly dried.

The plurality of hot air ducts (31) are separated from each other by slots (40) formed between a pair of hot air ducts (31) adjacent to each other. That is, a slot 40 is formed between the lower wall 32 of the hot air duct 31 disposed above the pair of hot air ducts 31 adjacent to each other and the upper wall 33 of the hot air duct 31 disposed below . A plurality of trays 43B disposed in the inner space 20 pass through the slots 40 and run over the right and left dry areas 18,

A pedestal 46 is fixed to the right inner side surface and the left inner side surface of the inner side surface defining the inner space 20 of the housing 11 to support the right and left edges of the tray 43B. That is, the right and left corners of the tray 43B are supported by the pedestal 46 and the central portion of the tray 43B is supported by the upper wall 33 of the hot air duct 31, . The tray 43B can be easily attached to and detached from the inner space 20 through the front surface of the opened housing 11 by opening the pair of front doors 23 and 25. [

The food dryer 10B is configured such that the internal space in which the object to be dried is placed is divided into a plurality of dry areas 18 and 19 by the hot air discharge partition 30B and the dried objects placed in the respective dry areas 18 and 19 And is heated and dried independently by the hot air discharged from the plurality of nozzle through holes (36). Therefore, even if different types of dried objects are dried at the same time, they can be prevented from transferring odor by arranging them in different dry regions 18 and 19, and the drying quality is improved. On the other hand, the user may arrange a drying object of the same kind in a plurality of drying zones 18 and 19 to proceed the drying operation.

The hot air generating unit 120 includes a ceramic heater 125 that generates heat by converting electrical energy into heat and a fan disposed behind the ceramic heater 125 and blowing the heat emitted from the ceramic heater 125 forward fan (121). The fan 121 is installed in the dryer housing 11 so as to be aligned with the air inlet opening 17 of the dryer housing 11. The ceramic heater 125 is the same as the ceramic heater 125 provided in the food drier 10 according to the first embodiment of the present invention, and thus a duplicate description will be omitted.

In the food dryer (10B) of the present invention, the hot air discharge partition (30B) is not necessarily arranged to separate the center of the inner space (20), but may be arranged to be deflected to one side. There is no need to provide only one hot air discharge partition, and two or three hot air outlet compartments may be provided to divide the internal space of the food dryer into three or four drying areas. Furthermore, not only one hot air generating unit but also two or three hot air generating units may be provided.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

10, 10B: Food dryer 11: Dryer housing
20: inner space 23, 25: front door
120: hot air generating unit 125: ceramic heater
126: outer wall 128: lattice inner wall

Claims (1)

A housing having an inner space formed therein; A hot wind generating unit for generating hot and dry hot air to be introduced into the internal space; And a plurality of drying areas disposed in the inner space to divide the inner space into a plurality of drying areas, wherein a flow path is formed to flow the hot air therein, And a hot air discharge partition having a plurality of nozzle openings formed therein for discharging the plurality of nozzle openings to the area, wherein the drying object is disposed in the plurality of drying areas, and the drying object is dried by the hot air discharged from the plurality of nozzle through holes ,
The hot air generating unit includes a ceramic heater having an outer wall and a lattice inner wall extending in a lattice pattern in a cross section in the outer wall to generate heat by converting electric energy into heat , The air introduced into the housing passes through the heat exchange passage between the inner walls of the grid, heat-exchanges and is discharged into the inner space as hot air,
The ceramic heater is formed by sintering the composition of the ceramic heater,
The composition of the ceramic heater includes a mixture of ceramic and metal, a dispersant, and a binder,
Wherein the ceramic and metal mixed powder includes at least one of aluminum nitride (AlN) and silicon nitride (Si ₃ N ₄ ), and the non-oxide ceramic powder accounts for 80 to 95% by weight of the total weight of the mixed ceramic and metal powder; And a metal powder occupying 5 to 20% by weight of the total weight of the mixed ceramic and metal powder.

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