JP6574406B2 - Food dryer - Google Patents

Description

  The present invention relates to a food drying apparatus using a planar heating element that irradiates far infrared rays.

  Conventionally, when a food or the like is dried and stored, an emphasis has been placed on efficiently performing in a short time, and as a result, a method of increasing the drying temperature has been employed. However, when foods and the like are dried, there is a problem that the quality is changed by raising the drying temperature, and the flavor and color are significantly deteriorated.

  Therefore, Patent Document 1 proposes a far-infrared device that uses a far-infrared heater that radiates far-infrared rays in the drying chamber, thereby making the product excellent in umami and meat quality without increasing the drying temperature. Has been. In Patent Document 1, far infrared heaters are installed on both side walls in a drying chamber in order to pass an amount of far infrared rays effective for drying an object to be dried.

JP 2001-103905 A

  In recent years, in the field of processed foods, it is economically required to increase the size of the drying chamber in the far-infrared device in order to mass-produce dried foods. For example, when placing flat foods such as fish openings or meat, which are dried foods, in the drying chamber, it is necessary not only to increase the size of the drying chamber but also to have a flat spread. It becomes.

  However, in the case where the drying chamber has a planar spread, the low-temperature far-infrared rays are generated by electromagnetic waves even if a planar heating element is installed on the side wall of the drying chamber, as in the far-infrared drying device proposed in Patent Document 1. Therefore, if the distance from the object is long, the effect is extremely reduced. For this reason, in such a far-infrared drying apparatus, even if a planar heating element is used in the drying chamber, the temperature of the entire surface becomes non-uniform, and there is a possibility that the placed object to be dried cannot be dried to the same quality. there were.

  Therefore, the present invention solves the above-described conventional problems, and uniformizes the temperature and air volume of the entire surface by the planar heating element in the drying chamber, so that the object to be dried is dried to the same quality. An object of the present invention is to provide a food drying apparatus capable of satisfying the requirements.

That is, the food drying apparatus according to one aspect of the present invention is a food drying apparatus for drying an object to be dried, and includes a mounting space having a width of 750 mm to 2000 mm and a depth of 450 mm to 800 mm. A drying chamber provided with a shelf on which the object to be dried is placed; an air intake portion provided on the front surface portion of the outer peripheral surface of the drying chamber; and a rear surface portion of the outer peripheral surface of the drying chamber facing the air intake portion. And an exhaust section having two or more exhaust fans, and a planar heating element for irradiating far infrared rays is further provided at the top and bottom of the drying chamber, and provided at the top and bottom of the drying chamber. The planar heating element has a height of 350 mm or more and 600 mm or less , the far infrared ray has a wavelength region of 6 μm or more and 14 μm or less, the temperature in the drying chamber is 15 ° C. or more and 22 ° C. or less, and the wind speed of air Is 0.8 m / s or more and 2.0 m / s or less .

The food drying device according to one embodiment of the present invention, the drying chamber, it is preferable that the pressure is reduced from atmospheric pressure below 0.5kPa than 0.05 kPa.

  According to the present invention, the temperature of the entire surface and the air volume are made uniform by the planar heating element in the drying chamber, so that the object to be dried can be dried to the same quality.

It is the schematic which shows the drying apparatus for foodstuffs concerning the 1st Embodiment of this invention. It is the schematic which shows the drying apparatus for foodstuffs concerning the 2nd Embodiment of this invention. It is the schematic which shows the drying apparatus for foodstuffs concerning the 3rd Embodiment of this invention. It is the schematic which shows the drying apparatus for foodstuffs which concerns on the 4th Embodiment of this invention. 3 is a thermograph showing temperature distribution and air volume in the entire drying chamber provided in the food drying apparatus according to Example 1. FIG. 2 is a wind diagram showing the wind speed in the entire drying chamber provided in the food drying apparatus according to Embodiment 1. FIG. 3 is a thermograph showing a temperature distribution in a central portion of a drying chamber provided in the food drying apparatus according to Example 1. FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily. In addition, the drying apparatus for foodstuffs concerning this embodiment can be applied as a thing for drying to-be-dried material by a far infrared ray.

(First embodiment)
FIG. 1 is a schematic view showing a food drying apparatus 100 according to the first embodiment of the present invention. As shown in FIG. 1, the food drying apparatus 100 according to the present embodiment includes a drying chamber 110 that dries an object to be dried, an intake unit 120 that supplies external air, and an exhaust unit 130 that exhausts water vapor and air. Have Hereinafter, each component will be described with reference to FIG.

  The shape of the drying chamber 110 is not particularly limited as long as the width is longer than the height. For example, the drying chamber 110 includes a mounting space having a width of 750 mm to 2000 mm and a depth of 450 mm to 800 mm. The drying chamber 110 stores an object to be dried and dries the object to be dried. The material of the drying chamber 110 is not particularly limited, but is preferably made of metal, and more preferably stainless steel (SUS304). Stainless steel materials have very good corrosion resistance, weldability and mechanical properties. The placement space refers to a space for placing or hanging a shelf for placing an object to be dried.

  Planar heating elements 111 and 112 that irradiate far-infrared rays are further provided at the top and bottom of the drying chamber 110. In the conventional food drying apparatus, unlike the food drying apparatus 100 according to the present embodiment, far-infrared heaters having a drying effect are provided on both side walls of the drying chamber. In this conventional food drying apparatus, in order to mass-produce dried products, the scale of the drying chamber was increased so that the width was larger than the height (planar spread).

  However, as with conventional food drying equipment, when a far-infrared heater is provided on the side wall of the drying chamber, the drying chamber is made larger by increasing the scale of the drying chamber and making the drying chamber wider in a plane. If the object to be dried placed on the shelf is located far from the far-infrared heater provided on the side wall of the drying chamber, the low-temperature far-infrared effect by the food drying apparatus according to the present embodiment becomes insufficient, and is desired. This food was in an insufficiently dried state. That is, in the conventional food drying apparatus, when the scale of the drying chamber is increased, the degree of drying varies greatly depending on the position where the object to be dried is placed.

  Therefore, the food drying apparatus 100 according to the present embodiment irradiates far infrared rays on the top and bottom of the drying chamber 110 so that the objects to be dried in the drying chamber 110 can be dried to the same quality. Further, the heating elements 111 and 112 are further provided. The planar heating elements 111 and 112 that are large in plan can be provided at the top and bottom of the drying chamber 110.

  In the food drying apparatus 100 according to the present embodiment, the planar heating element 111 provided at the top of the drying chamber 110 and the planar heating element 112 provided at the bottom are separated from each other by a height of 350 mm or more and 600 mm or less. It is characterized by that. When the separation distance is less than 350 mm, the drying space in the drying chamber 110 is limited, which is not suitable for mass production of dried food products. In addition, since a lot of work is performed by taking in and out the object to be dried, the efficiency is low. On the other hand, when the separation distance exceeds 600 mm, far infrared rays irradiated from the planar heating elements 111 and 112 provided at the top and bottom of the drying chamber 110 can reach the object to be dried in the center of the drying chamber sufficiently. Therefore, the object to be dried in the drying chamber 110 cannot be dried to the same quality.

  The planar heating elements 111 and 112 are obtained by impregnating and baking a carbon-based semiconductor compound on a cotton fabric in which warp yarns and weft yarns are independently provided at a predetermined interval in a mesh pattern, and an electrode conductor is provided on a part of the warp yarns. Provided. The planar heating elements 111 and 112 are laminated with an insulating film. By drying the object to be dried in the drying chamber 110, even if the discharged water is accumulated below, since the insulating film is laminated, there is no problem in the functions of the planar heating elements 111 and 112. The planar heating elements 111 and 112 may be provided on the inner wall or the inner wall side of the drying chamber 110.

  The planar heating elements 111 and 112 are not particularly limited, but include an electric panel heater including a conductive wire such as nichrome wire or conductive carbon, an electric sheet heater manufactured by laminating the conductive wire with a heat-resistant plastic film, hot water Panels, steam panels, etc. As the sheet heating element, an electric sheet heater is preferable, and among them, a carbon fiber sheet heater is more preferable because it can generate radiant heat.

  The insulating film is not particularly limited as long as it is a resin film having flexibility and heat resistance, and examples thereof include polyimide, polyester, and polyamide. Among these, it is preferable to use a film made of polyimide.

  When the temperature of the drying chamber 110 is 50 ° C. or higher, the food cells are destroyed and the food is corroded. Therefore, drying at a low temperature allows drying without destroying the nutrients of the food. The temperature is preferably less than 0 ° C., and more preferably 15 ° C. or more and 22 ° C. or less in order not to lose the color, taste and aroma of food.

  When the temperature of the drying chamber 110 is less than 5 ° C., the temperature of the drying chamber 110 is too low, and therefore it may take more time than necessary to evaporate the moisture contained in the material to be dried. On the other hand, when the temperature of the drying chamber 110 is 27 ° C. or higher, the temperature of the material to be dried approaches 30 ° C. or higher, which may increase the number of viable bacteria.

  Further, the far-infrared wavelength by the planar heating elements 111 and 112 may be selected according to the type of the object to be dried. The far-infrared wavelength irradiated by the planar heating elements 111 and 112 is often such that the absorption wavelength region of the food is between 2.5 μm and 30 μm depending on the wavelength region that absorbs water and organic matter, and further when absorbed by the food. Since it is directly converted into vibrational energy and rotational energy of molecules and atoms without being converted into energy of other modes, it is preferably 6 μm or more and 14 μm or less.

  When the far-infrared wavelength is less than 6 μm, it is too strong as infrared rays, so that not only the water contained in the material to be dried is evaporated but also other components may be adversely affected. On the other hand, when the far-infrared wavelength exceeds 14 μm, the time for evaporating the moisture contained in the material to be dried may be longer than necessary.

  You may enable it to adjust the heating temperature of the planar heating elements 111 and 112 suitably. As a result, it becomes easy to make the temperature of the entire drying chamber uniform, and the entire outside and inside of the object to be dried are heated by far infrared rays, so that the object to be dried is short even at a low temperature. It can be dried in time (2-5 hours).

  The shelf 113 is provided in the drying chamber 110 in parallel in the horizontal width direction, and places an object to be dried. The shape of the shelf 113 is not particularly limited as long as an object to be dried can be placed, and a planar net-like body is preferable. Although the material of this drying chamber 110 is not specifically limited, In order to dry a to-be-dried material efficiently by reflecting far-infrared rays, metal is preferable, and stainless steel (SUS304) is more preferable. Stainless steel materials have very good corrosion resistance, weldability and mechanical properties.

  The shelf 113 is a flat plate in which a plurality of holes are formed. Such holes can pass far-infrared rays radiated by the planar heating elements 111 and 112 provided at the top and bottom of the drying chamber 110, so even when the shelf 113 is provided in multiple stages. Thus, the object to be dried placed on the shelf 113 in the center can be dried more reliably.

  The shape of the hole is not particularly limited, but a rhombus (for example, a mesh shape), a quadrangle, a hexagon, or an irregular hexagon (generally referred to as a honeycomb structure or a honeycomb) is used.

  Furthermore, in the food drying apparatus 100 according to the embodiment of the present invention, the number of stages of the shelves 113 is not particularly limited, but is configured to be able to dry a large amount of objects to be dried in a shorter period of time and efficiently. Is preferred. Between shelves adjacent to each other in the vertical direction, the shelves 113 are mounted on the frame body 114 in a multi-stage manner with intervals, and are detachably mounted.

  The intake unit 120 includes an intake control chamber 121 and is provided on the front surface portion of the outer peripheral surface of the drying chamber 110. Water can be efficiently removed from the inside of the object to be dried by low-temperature far-infrared rays, air blowing, and reduced pressure. In consideration of the temperature of the drying chamber 110, the outside air is preferably supplied with air of 5 ° C. or higher and lower than 27 ° C., more preferably 15 ° C. or higher and 22 ° C. or lower. The intake control chamber 121 is provided between the drying chamber 110 and the intake unit 120. Since the intake control chamber 121 is spaced apart from the shelf 113 in the drying chamber 110, the intake control chamber 121 can reliably intake the air at the top and bottom of the drying chamber, and therefore sucks the air in the drying chamber 110. The amount can be made efficient and uniform.

  The intake section 120 is further provided with an intake filter (not shown) and / or an intake control plate (not shown). The intake filter is provided together with the intake control plate on the side surface of the outer peripheral surface of the drying chamber 110 for dust prevention and intake control. This fiber component is polyester fiber, acrylic fiber, nylon fiber, aramid fiber, vinylon fiber, polypropylene fiber, polyethylene fiber, polyvinyl chloride fiber, vinylidene fiber, polyurethane fiber, polyarylate fiber, ethylene vinyl alcohol fiber, acrylate fiber Fiber, polybenzoxazole fiber, polylactic acid fiber, rayon fiber, cupra fiber, acetate fiber, triacetate fiber, polyphenylene sulfide fiber, polysulfone fiber, polyethersulfone fiber, polytetrafluoroethylene fiber, wool, cotton, hemp, silk, melamine Fibers such as fiber, glass fiber, carbon fiber, silicon carbide fiber, and stainless steel fiber can be used. The intake filter has a thickness of about 0.1 mm to 10 mm.

  The intake control plate is provided on the front surface of the outer peripheral surface of the drying chamber 110 in order to adjust the intake air amount. The intake control plate is formed with a plurality of holes for sending outside air into the drying chamber. The material of the intake control plate is not particularly limited, and examples thereof include plastic and metal.

The exhaust unit 130 includes an exhaust fan 131 and an exhaust control chamber 132, and is provided on the back surface of the outer peripheral surface of the drying chamber 110 facing the intake unit 120. The exhaust unit 130 is provided to exhaust air and moisture in the drying chamber 110.

  The exhaust fan 131 and the exhaust control chamber 132 are provided between the drying chamber 110 and the exhaust unit 130, respectively. At least one exhaust fan 131 is provided. When a plurality of exhaust fans 131 are provided in parallel with the depth direction of the drying chamber 110, the amount of air exhausted from the drying chamber 110 can be made efficient and uniform.

  The exhaust fan 131 is preferably adjusted so that the air velocity in the drying chamber 110 is 0.1 m / s to 5.0 m / s, and is adjusted to be 0.8 m / s to 2.0 m / s. More preferably. This makes it easy to equalize the air volume over the entire drying chamber 110, and the entire outside and inside of the object to be dried are heated by far infrared rays, so that the object to be dried has a short time ( 2 hours to 5 hours).

  When the wind speed of air is less than 0.1 m / s, there is a possibility that a straight air flow cannot be obtained when the air passes between the upper and lower adjacent shelves 113. On the other hand, when the air wind speed exceeds 5.0 m / s, it may be difficult to maintain the inside of the drying chamber 110 at a desired temperature.

  Since the exhaust control chamber 132 is spaced apart from the shelf 113 in the drying chamber 110, the air in the top and bottom of the drying chamber can be reliably exhausted, so the air in the drying chamber 110 is exhausted. The amount can be made efficient and uniform.

  The exhaust unit 130 is further provided with an exhaust filter (not shown) and / or an exhaust control plate (not shown). The exhaust filter is provided on the back surface of the outer peripheral surface of the drying chamber 110 facing the exhaust unit 130 via an exhaust control plate.

  A plurality of holes are formed in the exhaust control plate for exhausting the air in the drying chamber 110. The area of the hole formed in the exhaust control plate is larger than the area of the hole formed in the intake control unit. As a result, a difference between the supply amount of air supplied into the drying chamber 110 and the exhaust amount 110 of air exhausted from the drying chamber 110 is generated, so that the inside of the drying chamber 110 is maintained in a reduced pressure state. The The numerical range of the pressure reduction is not particularly limited, but the pressure is preferably reduced from atmospheric pressure to 0.05 kPa to 0.5 kPa, more preferably from 0.1 kPa to 0.3 kPa. The material of the exhaust control plate is not particularly limited, and examples thereof include plastic and metal.

(Second Embodiment)
FIG. 2 is a schematic view showing a food drying apparatus 200 according to the second embodiment of the present invention. As shown in FIG. 2, the food drying apparatus 200 according to the present embodiment includes drying chambers 210 and 220 for drying an object to be dried, an intake unit 230 for supplying outside air, and an exhaust unit for exhausting water vapor and air. 240. The drying chambers 210 and 220 are partitioned by a partition plate 250 that is a flat plate. Further, planar heating elements 211, 212, 221, and 222 that irradiate far infrared rays are further provided on the top and bottom of the drying chamber 210 and on the top and bottom of the drying chamber 220.

  That is, in the food drying apparatus 200 according to the embodiment of the present invention, the drying chambers 210 and 220 may be provided in multiple stages so that a large amount of objects to be dried can be dried in a shorter period of time and efficiently. Since the second embodiment is the same as the first embodiment, description of each component is omitted.

  The material of the partition plate 250 is not particularly limited, but is preferably made of metal, and more preferably stainless steel (SUS304). Stainless steel materials have very good corrosion resistance, weldability and mechanical properties.

(Third embodiment)
FIG. 3 is a schematic view showing a food drying apparatus 300 according to the third embodiment of the present invention. As shown in FIG. 3, the food drying apparatus 300 according to the present embodiment has drying chambers 310a, 310b, and 310c for drying an object to be dried, intake portions 320a, 320b, and 320c for supplying outside air, steam, It has exhaust parts 330a, 330b, 330c for exhausting air. Further, planar heating elements 311a, 311b, 311c, 312a, 312b, 312c for irradiating far infrared rays are further provided on the top and bottom of the drying chambers 310a, 310b, 310c.

  In other words, the food drying apparatus 300 according to the embodiment of the present invention can have a plurality of drying chambers having the same configuration so that a large amount of objects to be dried can be dried in a shorter period of time and efficiently. Since the third embodiment is the same as the first embodiment, description of each component is omitted.

  Unlike the food drying apparatus 200 according to the second embodiment of the present invention described above, the food drying apparatus 300 according to the third embodiment of the present invention sucks air into one drying chamber 310a, 310b, 310c. Since each of the parts 320a, 320b, and 320c and the exhaust parts 330a, 330b, and 330c is provided, the temperature and the air volume of the drying chamber can be more uniformly made uniform.

(Fourth embodiment)
FIG. 4 is a schematic view showing a food drying apparatus 400 according to the fourth embodiment of the present invention. As shown in FIG. 4, the food drying apparatus 400 according to the present embodiment includes a drying chamber 410 that dries an object to be dried, an intake unit 420 that supplies outside air, and an exhaust unit 430 that exhausts water vapor and air. And a circulation unit 440 for circulating the exhausted air to the drying chamber. In addition, planar heating elements 411 and 412 that irradiate far infrared rays are further provided at the top and bottom of the drying chamber 410. Hereinafter, the circulation unit 440 will be described. Since the fourth embodiment is the same as the first embodiment, description of each component is omitted.

  The circulation unit 440 includes an intake passage 441 connected from the exhaust unit 430 to the intake unit 420, a circulation pump (not shown) that sends the exhausted air, and a cooling and dehumidifying chamber 442 that cools and / or dehumidifies the air. Have The air exhausted from the drying chamber 410 is sent to the cooling / dehumidifying chamber by a circulation pump, and this cooled and / or dehumidified air is supplied again from the intake unit 420 to the drying chamber 410 via the intake unit 420 by the exhaust fan 431. Is done. That is, in the fourth embodiment, a closed system is adopted.

  The shape of the intake passage 441 is not particularly limited as long as it is cylindrical. The material of the intake channel 441 may be any material that is not corroded by air or water exhausted from the drying chamber 410.

  Hereinafter, the present invention will be specifically described by way of examples, but is not limited thereto.

Example 1
In Example 1, thermographic evaluation was performed in order to confirm uniformity of the temperature in the drying chamber 110 by providing the planar heating elements 111 and 112 on the top and bottom of the drying chamber 110. First, the following food drying apparatus 100 was prepared.

<Drying equipment for food>
Outside dimensions of drying chamber: width 1600mm x depth 680mm x height 510mm
Shelf: Width 1200mm x Depth 600mm x 5 steps Body material: SUS304

  In the first embodiment, as shown in FIG. 1, after the sheet heating elements 111 and 112 are provided on the top and bottom of the drying chamber 110, the size and the material are adjusted to the third level, which is the middle level of the drying chamber 110. The shelf 113 was observed with a thermograph.

  FIG. 5 is a thermograph showing the temperature distribution and the air volume in the entire drying chamber provided in the food drying apparatus according to the first embodiment. FIG. 6 is a wind diagram showing the wind speed in the entire drying chamber provided in the food drying apparatus according to the first embodiment. FIG. 7 is a thermograph showing the temperature distribution in the central portion of the drying chamber 110 provided in the food drying apparatus 100 according to the first embodiment. As shown in FIG. 5, it was confirmed that the temperature and the air volume at the top, center, and bottom of the drying chamber were uniform throughout the drying chamber. Moreover, as shown in FIG. 6, it confirmed that the wind speed of the air was equalized with 1.1 m / s-1.4 m / s in the drying chamber 110. FIG. Furthermore, as shown in FIG. 7, the temperature difference between the region farthest from the side wall of the drying chamber and the region closest to the side wall of the drying chamber is about 0.01 to 0.02 ° C. It confirmed that the temperature in the center part of was uniform.

(Comparative Example 1)
On the other hand, referring to Japanese Patent Application Laid-Open No. 2001-103905, which is a conventional food drying apparatus, the planar heating elements are disposed on both side walls, unlike the arrangement of the planar heating elements in the food drying apparatus shown in FIG. Was provided as Comparative Example 1. The drying chamber was adjusted to the size and material of Example 1, and the third shelf, the middle stage of the drying chamber, was observed with a thermograph. As a result, it was confirmed that the temperature in the drying chamber at the midpoint from the planar heating elements on both side walls was lowered, and the temperature in the drying chamber was not uniformized.

(Summary)
As described above, the food drying apparatus 100, 200, 300, 400 according to the present embodiment is a food drying apparatus for drying an object to be dried, and has a mounting space that has a width of 750 mm or more and 2000 mm or less and a depth of 450 mm or more and 800 mm or less. A drying chamber 110 including a shelf on which an object to be dried is placed, a suction unit 120 provided on a front surface of the outer peripheral surface of the drying chamber 110, and a rear surface of the outer peripheral surface of the drying chamber 110 facing the suction unit 120 And an exhaust part 130 including an exhaust fan 131 provided in the part. Further, planar heating elements 111 and 112 for irradiating far infrared rays are further provided at the top and bottom of the drying chamber 110, and the planar heating elements provided at the top and bottom of the drying chamber have a height of 350 mm or more. It is separated by 600 mm or less.

  Thereby, in this embodiment, if the planar heating elements 111 and 112 provided at the top and bottom of the drying chamber 110 irradiate far-infrared rays, mutual interaction with the action of the air flowing from the intake portion 120 toward the exhaust portion 130 is achieved. Due to the action, the entire drying chamber 110 can be uniformly dried. As a result, the material to be dried can be dried to the same quality. Moreover, this dried product can improve storage stability and sugar content due to the evaporation of moisture.

100, 200, 300, 400 Drying device for food, 110, 210, 220, 310a, 310b, 310c, 410 Drying chamber, 111, 112, 211, 212, 221, 222, 311a, 311b, 311c, 312a, 312b, 312c, 411, 412 Planar heating element, 113 shelves, 114 frame, 120, 220, 320a, 320b, 320c, 420 intake section, 121 intake control chamber, 130, 230, 330a, 330b, 330c, 430 exhaust section, 131, 431 Exhaust fan, 132 Exhaust control chamber, 250 Partition plate, 440 Circulating part, 441 Intake flow path, 442 Cooling dehumidification chamber

Claims (2)

In a food drying apparatus for drying an object to be dried,
A drying chamber comprising a mounting space having a width of 750 mm or more and 2000 mm or less and a depth of 450 mm or more and 800 mm or less, comprising a shelf on which the object to be dried is mounted;
An air intake provided on the front surface of the outer peripheral surface of the drying chamber;
An exhaust part provided with two or more exhaust fans provided on the back surface part of the outer peripheral surface of the drying chamber facing the intake part,
A planar heating element that irradiates far infrared rays is further provided at the top and bottom of the drying chamber,
The planar heating elements provided at the top and bottom of the drying chamber are separated by a height of 350 mm or more and 600 mm or less ,
The far infrared ray has a wavelength region of 6 μm to 14 μm,
A drying apparatus for food, wherein the temperature in the drying chamber is 15 ° C. or more and 22 ° C. or less, and the air wind speed is 0.8 m / s or more and 2.0 m / s or less . The drying chamber, food drying device according to claim 1, characterized in that the pressure is reduced from atmospheric pressure below 0.5kPa than 0.05 kPa.