JP2008261543A - Drying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drying device capable of suppressing oxidation at low costs. <P>SOLUTION: This drying device is provided with a deodorizing device 50 comprising an oxidation catalyst 52 and a heater 53 for heating the oxidation catalyst 52 and disposed in a ventilation flue 17A, a seal means 15 disposed on a door 14 and capable of air-tightly closing the door 14, a trap portion 44 capable of closing a drain pipe 43, and a plug body 60 air-tightly closing an internal drain outlet 58, and the deodorizing device 50 is operated in a state of air-tightly blocking the inside of the main body 10 from the external by the seal means 15, the trap portion 44 and the plug body 60. The amount of oxygen in the air-tight main body 10 is constant amount decided by a volume in the main body 10, oxygen concentration in the main body 10 is gradually lowered in accompany with the progression of oxidative decomposition of an odor component by the deodorizing device 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drying apparatus used for drying food materials, wood, and the like.

Conventionally, what was described in patent document 1 is known as this kind of drying apparatus. In this case, the inner box is stored in the main body consisting of a heat insulating box with a space, so that a ventilation path is formed from the upper side of the inner box to both the left and right sides, and the outlets are formed on both the left and right sides of the inner box. Is opened, and the upper ventilation path is partitioned vertically, and the upper duct is equipped with a cooler and a cooling fan, and the lower duct is equipped with a circulation fan. When the circulation fan is driven, air is circulated and circulated in one direction over the ventilation path and the inner box, while the cooling fan is driven so that the air is circulated to the lower duct of the upper ventilation path. A part of the air is sucked into the upper duct side and dehumidified by passing through the cooler, and the dry air is merged at the outlet side of the upper duct to be used for drying the material to be dried stored in the inner box. It has become so.

In short, such a drying apparatus can be completed in a desired degree of dryness (weight after drying / weight before drying) by placing an object to be dried in an atmosphere of a predetermined temperature and humidity for a predetermined time. The product has various problems such as fading, discoloration, lipid oxidation, and off-flavor. For example, when fish open-drying is processed and processed in a drying device, fish oil contains a large amount of highly unsaturated fatty acids that are unstable to oxidation, making it extremely unstable to lipid oxidation. It is known to be deeply related to color, physical properties and nutritional value. Therefore, in order to prevent oxidation, vitamin C, E, emulsifiers, pH adjusters, coloring agents, etc. may be added to the fish to make up the surface, or glutamine may be added to maintain the taste. These are not necessarily favorable for consumers.

Therefore, as another anti-oxidation measure, the air in the drying chamber is sucked and exhausted with a vacuum pump or the like to reduce the oxygen concentration by reducing the pressure in the chamber (Patent Document 2), or the storage chamber is filled with nitrogen gas or the like Also known is one that lowers the oxygen concentration by substitution with an inert gas (Patent Document 3 and Patent Document 4).
Japanese Patent Laid-Open No. 2003-106766 JP 61-235676 A JP-A-2-203716 JP-A-4-93580

However, the former is expensive and large because it requires a body structure that can withstand vacuum and complicated control and maintenance of the exhaust system, and the latter also has a complicated gas replacement device and running inert gas. There is a problem that the cost is high. In both cases, there is a problem that it is not easy to open the door in order to check the material to be dried or to add the material during drying.
The present invention has been completed based on the above circumstances, and an object thereof is to provide a drying apparatus capable of suppressing oxidation at low cost.

The present invention is connected to a main body having a front opening made of a heat insulating box, a door attached to the front opening of the main body so as to be opened and closed, a circulation fan for circulating air in one direction in the main body, and a refrigeration apparatus. A cooling device provided in the air circulation path, and a drain pipe connected to a drain pan for receiving the dropped water from the cooler and discharging the dropped water to the outside. An oxidation-type deodorizing device provided in the circulation path with an oxidation catalyst, a sealing means provided on the door and capable of closing the door in an airtight manner, and a closing means capable of closing the drain pipe. It is characterized in that it is configured such that the internal air is circulated through the deodorizing device in a state where the inside of the main body is hermetically shut off from the outside by the sealing means and the closing means.

In the above configuration, when the drying operation is performed with the material to be dried stored in the main body and closed, air is circulated in the main body by the circulation fan and the circulating air is dehumidified while passing through the cooler. The material to be dried is dried by the dry air. The dripping water from the cooler is received by the drain pan, and then appropriately discharged outside the warehouse through the drain pipe. During the drying operation, circulating air containing the odor component generated from the material to be dried flows through the oxidation catalyst of the deodorization apparatus, so that the odor component in the air is oxidatively decomposed.
More specifically, the air is closed by the sealing means and the drain pipe is also closed by the closing means, so that the circulating air circulates to the deodorizing device in a state where the inside of the main body is shut off from the outside. ing. During the drying process, odorous components are circulated in the circulating air, but at the beginning of the drying process, the odorous components enter the body when the door is opened to store the objects to be dried. The odor component of the total of the odor component and the odor component generated from the material to be dried circulates, and is oxidatively decomposed by the oxidation catalyst of the deodorizer arranged in the circulation path, reducing the odor component, The consumption of oxygen in the air begins. Since the amount of oxygen in the main body kept airtight is a constant amount determined by the volume in the main body, the oxygen concentration in the main body gradually decreases with the progress of oxidative decomposition of odor components.

In addition, a main body having a front opening made of a heat insulating box, a door attached to the front opening of the main body so as to be openable and closable, and an inner surface of the main body with a space therebetween are housed in the main body and passed through the side surface. An inner box in which a mouth is formed, a ventilation path formed around the inner box, and a circulation fan which is provided in the ventilation path and circulates and circulates air in one direction from the ventilation path to the inside of the inner box by operation thereof. And a bypass path provided on the side of the ventilation path, a cooler connected to a refrigeration system and provided in the bypass path, and a drain pan receiving the dropped water from the cooler, A drying device provided with a drain pipe for discharging to the outside, an oxidation type deodorizing device provided with an oxidation catalyst and provided in the ventilation path, and the door provided airtightly closed Possible sealing means and the drain pipe can be closed And chain means, is provided, may be configured to circulate-compartment air in the deodorizing device while blocking hermetically inside the body from the outside to the sealing means by said closing means.
In the above configuration, when the drying operation is performed in a state where the object to be dried is stored in the inner box and closed, air is circulated to the inner box by the circulation fan, and part of the circulating air flows to the bypass path to be cooled. The material to be dried is dried by being dehumidified while passing through the container, and the dried air is combined with the circulating air and put into the inner box. The dripping water from the cooler is received by the drain pan, and then appropriately discharged outside the warehouse through the drain pipe. During the drying operation, circulating air containing the odor component generated from the material to be dried flows through the oxidation catalyst of the deodorization apparatus, so that the odor component in the air is oxidatively decomposed.

Furthermore, it is good also as the following structures.
The deodorizing device is provided with a heater for heating the oxidation catalyst. In this configuration,
Oxidative decomposition of odor components in the oxidation catalyst is further promoted.
The bottom wall of the main body is provided with a plug for closing the drain in the cabinet in an airtight manner. In this type of drying device, there are many opportunities to wash the interior of the cabinet with water, and there are many cases with a relatively large interior drain. However, the interior of the main body is kept airtight by closing the interior drain with a stopper. Effective above.

The closing means is a trap portion formed in the drain pipe. In this structure, the dripping water from a cooler is stored in the trap part of a drain pipe, and the airtightness in a main body is ensured.
The closing means is an electromagnetic on-off valve provided in the drain pipe. In this configuration, the airtightness in the main body can be ensured by closing the electromagnetic on-off valve, and the dropped water can be discharged by opening it appropriately.
The closing means is a pressure relief valve that closes when the accumulated water is opened and drained when the weight of the accumulated water exceeds a predetermined value. In this configuration, the dripping water is automatically drained appropriately, and immediately after draining, the valve is closed, which is effective in keeping the inside of the main body airtight.

In the cooler, the cooling temperature by the operation of the refrigeration apparatus is maintained at 0 ° C. or higher. In this configuration, water is not stored in the trap part of the drain pipe at the initial stage of the drying operation, so there is no airtightness in the main body. Decomposition is smooth. This can deodorize the inside of the main body in the initial stage and suppress the smell from being transferred to the object to be dried. When the predetermined time has elapsed since the start of operation, the temperature of the cooler is 0 ° C. or higher, so that water adhering to the cooler dripped and collects in the trap part. It is said. When the above action is exhibited, the operation of closing the drain pipe is automatically obtained by storing water in the trap portion, so that it is not necessary to provide means for controlling the opening / closing of the electromagnetic on-off valve by a timer.

Control means for allowing energization to the heater of the deodorizing apparatus is provided only after a predetermined time has elapsed after the start of the refrigeration apparatus. In this configuration, dehumidification in the cooler starts when the refrigeration system is started, and dripping water from the cooler accumulates in the trap part and the drain pipe is closed, i.e., the inside of the main body is airtight only. Energized. Generation of a low oxygen atmosphere by combustion oxidation of odorous components can be efficiently performed, power can be saved, and the life of the catalyst can be extended.

In the present invention, the oxygen concentration in the main body can be lowered by circulating the circulating air in the warehouse through the oxidative deodorizer while keeping the inside of the main body airtight. In order to make the main body airtight, it is possible to cope with a simple structure such as providing a sealing means on the door and a closing means on the drain pipe, and the oxidation type deodorizing apparatus itself is not expensive and the running cost can be suppressed,
As a result, oxidation can be suppressed at low cost.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
1 and 2, reference numeral 10 denotes a main body made of a heat insulating box having a front opening.
Inside the 0, an inner box 11 made of a heat conducting member such as a metal plate is mounted. In the inner box 11, the top plate 11 </ b> A and the left and right side plates 11 </ b> B and 11 </ b> C are assembled in a front gate shape that is slightly smaller than the opening of the main body 10, and each plate 11 </ b> A to 11 </ b> C The inner side of the inner box 1 is attached with an interval between the inner side and the inner side of the inner box 1.
A drying chamber 12 is constituted by the interior of 1. In the drying chamber 12, a plurality of shelf nets 13 are mounted in a plurality of stages via shelf receivers (not shown), and an object to be dried such as food is placed on the shelf nets 13.
A heat-insulating door 14 is attached to the front opening 10A of the main body 10 so as to be able to swing open and close.
A packing 15 as a sealing means is attached to the peripheral edge of the back surface side of 4 over the entire circumference. When the door 14 is closed, the packing 15 is elastically brought into contact with the front peripheral edge of the front opening 10A of the main body 10 to be hermetically closed.

The front surface of the space between the inner box 11 and the main body 10 is closed by the cover plate 16, and therefore, the upper ventilation path 17 </ b> A is provided between the outer surface of the inner box 11 and the inner surface of the main body 10. Ventilation path 17B
And the right ventilation path 17C is formed. Each ventilation path 17 </ b> A to 17 </ b> C has a width having a size approximately equal to the depth of the inner box 11.
An inlet 18 is formed in the left side plate 11B facing the left side ventilation path 17B in the inner box 11, and a plurality of outlets 19 are opened in the right side plate 11C facing the right side ventilation path 17C. ing. On the inflow port 18 side, a guide plate 18A that protrudes horizontally from the lower edge toward the outside is formed.

At the left end (exit) as viewed from the front of the upper ventilation path 17A, a plurality of circulation fans 22 are arranged side by side over the entire width. When the circulation fan 22 is driven, as shown by the arrow in FIG. 1, the air discharged from the circulation fan 22 flows downwardly through the left ventilation path 17B and sequentially passes from each inlet 18 to the drying chamber. 12 flows into the drying chamber 12 to the right, exits from the outlet 19 and rises on the right ventilation path 17C, and then passes through the upper ventilation path 17A to the circulation fan 2
A circulation flow such as circulation to the left toward 2 occurs. That is, the circulation path 23 by the circulation fan 22 is configured.

A cooler chamber 25 that houses the cooler 32 is provided on the upper surface of the main body 10. Specifically, a horizontally long rectangular window hole 26 is opened at a position near the right end of the upper surface of the main body 10 and in the center in the depth direction, and above the window hole 26, heat insulation such as polystyrene foam is provided. A cooler chamber 25 is formed in the interior by covering with a heat insulating case 27 having a box shape with an open bottom surface formed integrally with the material. A heat-insulating partition wall 28 is fitted to the center of the window hole 26 in the left-right direction and is partitioned left and right, and a suction port 29 is formed on the right side of FIG. 1 and a discharge port 30 is formed on the left side.

A cooler 32 is provided in the cooler chamber 25 above the partition wall 28. The cooler 32 is circulated and connected by a refrigerant pipe to a refrigeration apparatus (comprising a compressor, a condenser, etc .: not shown) installed outside the cooler chamber 25 on the upper surface of the main body 10, and a well-known refrigeration cycle is performed. It is configured. Two cooling fans 35 are provided in front of the suction side surface of the cooler 32.
Are equipped side by side.
When the cooling fan 35 is driven, as shown by the arrow in FIG. 1, a part of the air that has circulated from the right ventilation path 17C to the right end (inlet) of the upper ventilation path 17A in the circulation path 23 is sucked. The air is sucked into the cooler chamber 25 upward from the port 29 and circulates through the cooler 32 to the left, and then discharged downward from the discharge port 30 to the upper ventilation path 17A. A passage extending from the suction port 29 through the cooler 32 to the discharge port 30 is a bypass passage 37 according to the present invention.

The suction port 29 is equipped with a temperature sensor 39 for detecting the temperature of the air flowing through the bypass passage 37. Since the suction port 29 in the bypass passage 37 is open to the circulation passage 23 passing through the drying chamber 12, as long as the circulation fan 22 is operated and the circulation passage 23 is formed, The detected temperature is regarded as the internal temperature (temperature in the drying chamber 12).

A drain pan 40 is installed on the upper surface of the partition wall 28 so as to receive the cooler 32 and the lower surface side of the cooling fan 35. As will be described later, the drain pan 40 functions to receive dripping water that adheres to the cooler 32 and subsequently drops when the cooler 32 exhibits a dehumidifying action. When the defrosting operation is performed, the defrosting water functions from receiving defrosted water from the cooler 32 and the cooling fan 35.

As shown in FIG. 2, the bottom surface of the drain pan 40 is an inclined surface that is inclined downward toward the back side, and a drain port 41 is opened at the lower end of the back surface plate 40 </ b> A of the drain pan 40. . A drain pipe 43 is connected to the drain port 41, and the drain pipe 43 is connected to the cooler chamber 2.
5, penetrates the back wall 27 </ b> A of the heat-insulating case 27, protrudes horizontally to the back surface 10 </ b> B side of the main body 10, and then hangs down along the back surface 10 </ b> B of the main body 10.
However, a trap portion 44 as a closing means is formed at a substantially central height position of the hanging portion in the drain pipe 43. The trap portion 44 is called a so-called U-shaped or S-shaped trap. The trap portion 44 is formed to rise in a U shape in the middle, and forms an inverted U shape from the rising end 44 </ b> A so that the outlet 45 side of the drain pipe 43 is connected to the trap portion 44. It has a suspended shape.

A heater 47 is disposed slightly downstream of the position where the discharge port 30 of the bypass passage 37 is opened in the upper ventilation passage 17A. This heater 47 is spirally wound, for example,
It is mounted across the full width (depth) of the upper ventilation path 17A.
Further, the lower position of the partition wall 28 in the upper ventilation path 17A, in other words, the bypass path 3
A combustion-type deodorizing device 50 is provided at a position between the seven suction ports 29 and the discharge ports 30. As schematically shown in FIG. 3, the deodorizing device 50 includes a metal honeycomb catalyst 52 (hereinafter referred to as a catalyst 52) fitted in a cylindrical case 51, while a sheathed heater or the like is provided on the intake side thereof. It has a structure in which a deodorizing heater 53 for promoting deodorization is provided.

Specifically, the catalyst 52 is formed by baking on the surface of a stainless steel honeycomb carrier in a state where noble metal fine particles such as platinum and palladium are dispersedly supported on the ceramic component. As described above, in the case of using the noble metal catalyst, the air can be passed through the catalyst 52 while being heated to a relatively low temperature such as about 300 ° C., so that the combustion oxidative decomposition, that is, the deodorization of the odor component can be performed. Have.
Similarly, on the upstream side of the circulation fan 22 in the upper ventilation path 17A, the deodorizing filter 5 is provided.
5 is equipped. The deodorizing filter 55 is, for example, an artificial enzyme supported on the surface of a honeycomb carrier, and can exhibit a deodorizing function from a low temperature to a normal temperature region.

In this type of drying apparatus, the inside of the inner box 11 may be frequently washed with water, and a relatively large-diameter internal drainage pipe 58 is provided on the bottom surface 10C of the main body 10 in order to drain the washing water. It has been. Specifically, the bottom surface 10C of the main body 10 is slightly inclined downward from the periphery toward a predetermined position slightly closer to the right side from the center portion in the frontage direction and a little deeper from the front opening 10A. The above-described internal drainage pipe 58 is fitted to the lowermost surface of the bottom surface 10C so as to protrude downward from the outer bottom surface. The upper end opening 59 of the internal drainage pipe 58 is formed as a tapered surface 59A having a downward slope toward the inner periphery. On the other hand, a rubber or soft synthetic resin plug body 60 having a substantially frustoconical shape having a tapered peripheral surface aligned with the taper surface 59A is provided, and this plug body 60 is connected to the upper end of the internal drain pipe 58. By being press-fitted into the opening 59, the internal drainage pipe 58 is hermetically sealed from the outside. In addition,
A knob (not shown) is provided on the upper surface of the plug body 60, and when draining in the warehouse, the plug body 60 may be removed by pulling the knob.

Then, the effect | action of this embodiment is demonstrated.
The drying operation will be described with reference to the timing chart of FIG. Preset temperature T for drying
₁ is set in the range of 5 to 40 ° C. Along with this set temperature is changed temperature of the cooler 32, for example, the internal set temperature T ₁ is "5 ° C.", "20 ° C.", when "35 ° C.", the temperature of the cooler 32, respectively They are “around −3 ° C.”, “around 7 ° C.”, and “around 15 ° C.”.
When the start switch is turned on, the cooling fan 35 provided in the bypass passage 37 and the circulation fan 22 provided in the circulation passage 23 are driven. One minute later, the heater 47 and the deodorizing device 50 are provided. The deodorizing heater 53 is energized. After 3 minutes from the start, the refrigeration system (compressor and condenser fan) is driven. Thereby, as shown by the arrow line in FIG. 1, air flows through the circulation path 23, and a part of the air that has circulated from the right ventilation path 17 </ b> C to the right end of the upper ventilation path 17 </ b> A from the suction port 29 of the bypass path 37. By being sucked upward into the cooler chamber 25 and passing through the cooled cooler 32, water vapor in the air is condensed on the cooler 32, that is, dehumidified to generate dry air. This dry air is discharged downward from the discharge port 30 to the upper ventilation path 17A, merged with the air flow flowing leftward through the upper ventilation path 17A, and then heated by passing through the heater 47, This is continued, and the dehumidified air is circulated through the circulation path 23, that is, the drying chamber 12 while being gradually heated, and the inside of the drying chamber 12 is gradually heated (initial heating).
When the temperature of the cooler 32 exceeds 0 ° C., the condensation on the cooler 32 is continuously dropped and received by the drain pan 40, and then flows down the drain pipe 43 and is collected in the trap unit 44. When the water level exceeds the rising end 44A, it flows downward and is discharged from the outlet 45 at the lower end.

The temperature detected by the temperature sensor 39 of the suction port 29 is a preset drying temperature set value T.
_{When the} upper limit value T _1u higher than ₁ is reached, the energization of the heater 47 is interrupted,
The temperature of the circulating air gradually decreases, and the internal temperature also decreases accordingly. When the temperature detected by the temperature sensor 39 reaches a lower limit value T _1d that is lower than the drying temperature setting value T ₁ by a predetermined temperature, the heater 47 is energized again, and the circulating air is heated to raise the temperature. The internal temperature gradually increases. Thereafter, by repeating the above, the inside temperature (drying temperature) is maintained substantially at the set temperature T ₁ (control heating). During this time, the material to be dried housed in the drying chamber 12 is accelerated in the evaporation of the contained water, that is, gradually dried.

Further, during the drying operation, the deodorizing heater 53 of the deodorizing device 50 is energized, so that the catalyst 52 is about 30.
When the temperature is raised to 0 ° C. and the circulating air flows through the catalyst 52, the odor components in the air are oxidatively decomposed. More specifically, the odor component is adsorbed on the catalyst 52 together with oxygen or the like and activated to be burnt oxidatively decomposed and harmless and non-brominated.
For example, hydrocarbon compounds such as methane gas contained in the ambient atmosphere of the installation location of the drying device, and sulfur compounds that are volatile compounds involved in the smell of fresh fish as representative of the object to be dried,
The reaction formula for the oxidative decomposition of nitrogen compounds, organic acids, and aldehydes is shown below.

[Hydrocarbon compounds]
Hydrocarbons _{C m H n + [(2m} + n / 2) / 2] O 2 → mCO 2 + n / 2H 2 O
[Sulfur compounds]
Methanethiol CH ₃ SH + 3O ₂ → CO ₂ + 2H ₂ O + SO ₂
Dimethyl sulfide CH ₃ SCH ₃ + 9 / 2O ₂ → 2CO ₂ + 3H ₂ O + SO ₂
[Nitrogen compounds]
Ammonia NH ₃ + 7 / 4O ₂ → NO ₂ + 3 / 2H ₂ O
Dimethylamine (CH ₃ ) ₂ NH + 19 / 4O ₂ → 2CO ₂ + 7 / 2H ₂ O + NO ₂
Trimethylamine (CH ₃ ) ₃ N + 25 / 4O ₂ → 3CO ₂ + 9 / 2H ₂ O + NO ₂

[Organic acid]
Formic acid HCOOH + 1 / 2O ₂ → CO ₂ + H ₂ O
Acetic acid CH ₃ COOH + 2O ₂ → 2CO ₂ + 2H ₂ O
Propionic acid CH ₃ CH ₂ COOH + 7 / 2O ₂ → 3CO ₂ + 3H ₂ O
Butyric acid CH ₃ (CH ₂ ) ₂ COOH + 5O ₂ → 4CO ₂ + 4H ₂ O
[aldehyde]
Propanal CH ₃ CH ₂ CHO + 4O ₂ → 3CO ₂ + 3H ₂ O
Butanal CH ₃ (CH ₂ ) ₂ CHO + 11 / 2O ₂ → 4CO ₂ + 4H ₂ O
Pentanal CH ₃ (CH ₂ ) ₃ CHO + 7O ₂ → 5CO ₂ + 5H ₂ O
Hexanal CH ₃ (CH ₂ ) ₄ CHO + 17 / 2O ₂ → 6CO ₂ + 6H ₂ O
As shown in the above reaction formula, the odor component is changed to CO ₂ , H ₂ O, SO ₂ , NO ₂ . Also, oxygen is consumed in the reaction.

Here, the oxidation of lipid will be described by taking a salted fish as an example. When manufacturing fresh fish, the raw fish is opened and the internal organs are removed and washed, soaked in salt water for a certain period of time, and then sun-dried.
Alternatively, drying is performed by operating the dryer in a shelf network in a cold air dryer. At this time, the smell of the fish is slight when the original fish is opened, but it is well known that the generation of smell increases as the drying time elapses and the smell of the fish is felt. This is because the drying time is as long as 3 to 12 hours, so that lipid oxidation proceeds in proportion to the passage of time. Moreover, when the drying temperature is high, lipid oxidation is promoted, and the amount of odor generated is further increased.
Therefore, in order to avoid it, it is a windy place on the coast, choose a shaded place avoiding direct sunlight, or cold air dryer that can stably process dried fish throughout the year regardless of the weather Then, the device which prevents excessive oxidation, such as restraining a drying temperature to about 20 degreeC, is required.
In addition, in order to directly reduce the oxygen concentration in the storage, it has been proposed to reduce the pressure in the storage or to replace with an inert gas such as nitrogen gas. This is as described above.

On the other hand, in the present embodiment, the door 14 is hermetically closed via the packing 15, the drain pipe 43 is also closed with water accumulated in the trap portion 44, and the internal drain pipe 58 is also closed with the plug 60. As a result, the drying operation is performed in a state where the inside of the main body 10 (hereinafter also referred to as the inside of the warehouse as appropriate) is airtightly shut off from the outside and the combustion type deodorizing apparatus 50 is activated.
During the drying process, odor components are circulated in the circulating air, but at the beginning of the drying process, the ambient air of the drying apparatus that has entered the cabinet when the door 14 is opened to store the object to be dried. The odor component of the total amount of the odor component inside and the odor component generated from the material to be dried circulates, and the ventilation path 17
Combustion oxidative decomposition is performed by the combustion-type deodorizing device 50 arranged in A, and the reduction of odor components and the consumption of oxygen in the air in the cabinet are started. Since the amount of oxygen in the chamber kept airtight is a fixed amount determined by the volume in the chamber, the oxygen concentration in the chamber gradually decreases as combustion oxidative decomposition of odor components proceeds.

When the oxygen concentration in the chamber kept airtight is lowered, the oxidation of lipids in the material to be dried is suppressed, so that the generation of odor components is reduced. When drying in a low oxygen atmosphere is in progress, when the door 14 is temporarily opened and closed and the outside air enters the cabinet, the oxygen contained in the outside air is mainly burned and oxidized by the odor components remaining in the cabinet. Used for disassembly. This is because the combustion oxidative decomposition of odor components is a short-time reaction, and the lipid oxidation reaction requires a longer time than the combustion oxidative decomposition reaction. Therefore, even if the door 14 is temporarily opened and closed, a low oxygen atmosphere is continuously maintained.
As a result of the suppression of lipid oxidation, the generation of odor components is small, and quality deterioration such as taste, color tone, physical properties, and nutritional value is prevented.

In addition, if the material to be dried is not sterilized by heating before starting to dry, in most cases, general bacteria adhere to the surface of the material to be dried, and airborne bacteria may also be latent in the air in the cabinet. Yes. In the case of freshly drying fresh fish, the number of bacteria attached to the finished product is a big problem because it moves to the drying process without heat sterilization. For example, in a conventional cold-air drying cabinet, when the internal temperature exceeds 20 ° C., general bacteria adhering to the surface of the material to be dried and suspended bacteria adhering to the fall are suitable for breeding and eating. It may disappear. Therefore, in order to suppress the oxidation of the lipid described above and the growth of this fungus, the internal temperature needs to be 20 ° C. or lower.

In this regard, in this embodiment, in the deodorizing device 50 disposed in the circulation path 23 (ventilation path 17A) of the airtight internal space, the temperature of the catalyst 52 is maintained at a high temperature of about 300 ° C. as described above. It reduces odor components and consumes oxygen in the air in a low oxygen atmosphere, so aerobic bacteria (non-oxygen-free breeding) out of general bacteria attached to the surface of the material to be dried Can prevent the growth of bacteria). In addition, airborne bacteria are sucked into the deodorizing device 50,
It contacts the deodorizing heater 53 or the catalyst 52 and burns away. Therefore, as time passes, aseptic low-oxygen dry air circulates in the cabinet, and in addition to suppressing lipid oxidation as described above, it adheres to the surface of the object to be dried. The growth of bacteria can also be suppressed.

Moreover, since drying can be performed with the internal temperature exceeding 20 ° C., the drying time can be shortened. For example, it takes 6 hours to dry 360 horse mackerel openings (100 g / animal) at an internal temperature of 20 ° C. to a dryness (weight ratio) of 85%, whereas the internal temperature is 35 ° C. If there is, it can be dried in 4 hours.
Furthermore, when the material to be dried is fish, the protease activity of the proteolytic enzyme, which is an endogenous enzyme, can be increased (1.8 times higher at 35 ° C compared to 20 ° C), and as a result, The amount of amino acids can be increased by about 10% compared to 20 ° C.

Here, as an example of an object to be dried, “Aji-no-kai” is given, and experimental results when various dryings are performed are compared and examined. “Aji-no-Aki” was dipped in salt water and then dried in cold air, aged, dried in the sun, and dried in the shade to obtain samples. The cold air drying is operated at a chamber temperature of 20 ° C. in the cold air drying chamber, and the aging drying is performed at the chamber temperature of 35 ° C. by the drying apparatus of the present embodiment. Sun-dried is dried by direct sunlight on the coast (the outside temperature at that time 35
℃), shade drying is a thing dried in the shade of the shore (the outdoor temperature is 35 ℃ at that time).

When the enzyme activity of protease, a proteolytic enzyme in the edible edible portion, is compared, FIG.
As shown in Fig. 4, the enzyme activity of cold-air drying, sun drying, and shade drying is lower than before drying.
Aging and drying became high. In detail, aging drying showed about 1.8 times the enzyme activity compared with cold air drying, sun drying, and shade drying.
On the other hand, FIG. 6 is a comparison of the amount of free amino acids in the same edible portion. Compared to before drying, cold air drying and sun drying were almost the same, and shade drying was slightly less. Aging and drying increase and increase by about 10% compared to other dry forms. This is because the enzyme activity is high, so that the protein of fish meat is degraded and the amount of free amino acids, which is the total amount of peptides and amino acids, is increased.

Here, in order to confirm the factor which has the said effect further, the deodorizing apparatus 50 was stopped on the same conditions as aging drying, the sample was made, and the amount of free amino acids was measured. The result was identical to the cold air drying. In general, the enzyme activity is known to be affected by temperature, pH, etc., and the experiment was carried out because the internal temperature seems to be higher at 35 ° C than at 20 ° C. It has been found that an increase in the internal temperature does not directly lead to an increase in the amount of free amino acids.
On the other hand, the aging and drying according to the present embodiment is also a result of operating the deodorizing device 50, and the low oxygen atmosphere accompanying the operation of the deodorizing device 50 increases the enzyme activity, and consequently increases the amount of free amino acids, compared to the others. On the contrary, it proves that you can make dried fish with a lot of taste.

Moreover, FIG. 7 is a comparison of the chromaticity of the same edible portion. "A *" is Lab
The chromaticity in the red direction of the color system is a vivid color as the value increases, and a dull color as the value decreases. Compared with the drying, the cold-air drying is slightly discolored, and the sun-dried and shade-dried are greatly discolored. In the aging drying, the red color is brighter than before drying.
Sun-dried and shade-dried are those in which lipid oxidation has progressed under the influence of ultraviolet rays. In cold air drying, lipids are oxidized by the air in the cabinet. Aging and drying is bright as a result of inhibiting lipid oxidation.
The oxygen concentration on flat ground is 21% and is affected by temperature, humidity, and atmospheric pressure. The oxygen concentration in the experiment was 21% for cold air drying, sun drying, and shade drying, but a decrease of several% was observed in the drying apparatus according to this embodiment.

As described above, according to the present embodiment, the oxygen concentration in the chamber can be lowered by operating the combustion-type deodorizing device 50 while keeping the chamber airtight. In order to make the interior airtight, it is possible to cope with a simple structure in which a packing 15 is provided on the door 14, a trap portion 44 is provided on the drain pipe 43, and a plug body 60 is provided on the inside drain pipe 58. The device 50 itself is not expensive, and the running cost may be determined by considering the power supply to the deodorizing heater 53. As a result, the oxidation can be suppressed at a low cost.

Further, as a means for closing the drain pipe 43 for draining the dripped water from the cooler 32 to the outside, a trap part 44 is adopted, and the temperature of the cooler 32 is maintained at 0 ° C. or higher during the drying operation. In this case, the following special effects are exhibited.
If water is not stored in the trap portion 44 at the start of operation, there is no airtightness in the cabinet.
Therefore, in the combustion type deodorizing apparatus 50, since there is no decrease in oxygen, combustion oxidative decomposition of odor components is performed smoothly. This is effective in first deodorizing the inside of the cabinet and suppressing the smell from being transferred to the object to be dried. When a certain amount of time has elapsed after the start of operation, the cooler 32 is at 0 ° C. or higher, so that dew adheres to the cooler 32 and the dripping water flows down to the drain pipe 43 to trap part 4.
4 and finally the drainage pipe 43 is air-closed to make the interior airtight.
As mentioned above, immediately after the start of operation, the chamber odor is positively subjected to combustion oxidative decomposition without maintaining the chamber hermeticity, and then the chamber is hermetically sealed to reduce the oxygen concentration in the chamber. In this case, the drain pipe 43 is automatically switched from opening to closing when water is collected in the trap portion 44. For example, compared to means such as opening and closing an electromagnetic on-off valve using a timer,
It can be inexpensively supported.

<Embodiment 2>
FIG. 8 shows a second embodiment of the present invention. In the second embodiment, as a means for closing the drain pipe 43 that drains dripped water or the like from the cooler 32 to the outside, an electromagnetic on-off valve 65 is interposed in the middle of the hanging part of the drain pipe 43. .
The electromagnetic on-off valve 65 discharges the dropped water when the valve is opened and closes the drain pipe 43 when the valve is closed.
The valve opening timing is set in advance by experimentally obtaining the amount of dripping water. For example, in the case where the refrigeration apparatus is controlled so that the temperature of the cooler 32 is 0 ° C. or higher and the dehumidification is continuously performed in the cooler 32, the amount of dripping is small immediately after the start of operation, so that it is relatively long. After the time (about 20 minutes) has elapsed, the valve is opened (about 30 seconds). After that, the amount of dripped water is almost constant, so the valve is closed (about 5 minutes) and opened (about 30 seconds). Repeat and to discharge the dripping water.
Since the amount of dripped water decreases as the degree of drying of the object to be dried progresses, when the amount of object to be dried stored in the drying chamber 12 is always constant, the valve closing time is set according to the passage of time (degree of drying). You may make it lengthen. In any case, the drain pipe 43 is closed immediately after the start of the drying operation, which is effective for keeping the interior airtight.

The temperature of the cooler 32 is set to less than 0 ° C., and frost is attached to the cooler 32. After the predetermined amount of frost formation, the temperature of the cooler 32 is increased to a high temperature (about 20 ° C.) to freeze the frost. In what controls an apparatus, the electromagnetic on-off valve 65 can be opened for a predetermined time and the dripping water (defrost water) can be discharged in the frost melting process.
Although not shown, a water level sensor may be provided on the inlet side of the electromagnetic opening / closing valve 65, and the valve may be opened by an on signal of the water level sensor and closed by an off signal.

<Embodiment 3>
FIG. 9 shows Embodiment 3 of the present invention. In the third embodiment, a pressure relief valve 67 (relief valve) is provided in the middle of the hanging portion of the drainage pipe 43 as means for closing the drainage pipe 43 that discharges dripping water or the like from the cooler 32 to the outside. It has been.
When the pressure relief valve 67 is provided, the drain pipe is opened when the weight of the water stored in the drain pipe 43 reaches a predetermined value to discharge the stored water and close when the stored water runs out. 43 is air-closed and thus functions to keep the interior airtight.

<Embodiment 4>
A fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, in the drying apparatus shown in the first embodiment, the timing of starting energization to the deodorizing heater 53 in the combustion type deodorizing apparatus 50 is changed.
In the first embodiment, energization to the deodorizing heater 53 of the deodorizing device 50 is performed at the timing X in FIG.
Is going on. At this timing X, since the refrigeration apparatus is not yet operated, water is not stored in the trap portion 44 of the drain pipe 43. Even if water is stored in the trap unit 44 during the previous drying operation, if the interior is in a dry state while the operation is stopped, the water may evaporate in a short time. Further, dehumidification is started in the cooler 32 when the operation of the refrigeration apparatus is started, and the water stored in the trap unit 44 is close to the cooler 32 and may re-evaporate.
The present invention basically intends to operate the combustion type deodorizing device 50 while keeping the inside of the chamber airtight, thereby burning and oxidizing the odor component and accompanyingly generating the inside of the chamber in a low oxygen atmosphere. However, at the above-described operation timing, the deodorizing apparatus 50 operates in a state where the interior is not airtight.

Therefore, in the fourth embodiment, as shown in the timing chart of FIG. 10, energization to the deodorizing heater 53 is started at a timing B ₁ when a predetermined time t ₁ has elapsed from a timing A at which the operation of the refrigeration apparatus is started. Is done. This delay time t ₁ is obtained experimentally, and after the refrigeration apparatus is operated, dripped water (dehumidified water) from the cooler 32 flows down and is stored in the trap portion 44, and the drain pipe 43 is closed and stored. It is determined by measuring the time until the inside becomes airtight.
According to the above-described operation control, dehumidification in the cooler 32 is started by starting the refrigeration apparatus, dripping water from the cooler 32 is accumulated in the trap portion 44, and the drain pipe 43 is closed, that is, the interior is airtight. For the first time, the deodorizing heater 53 of the combustion type deodorizing device 50 is energized.
Therefore, it is possible to efficiently generate a low-oxygen atmosphere by combustion oxidation of odor components. Specifically, power can be saved and the life of the catalyst can be extended.

The delay time described above can be arbitrarily set. For example, when the drying apparatus is used so as to store an object to be dried after the inside temperature reaches a desired drying temperature after the drying operation is started, the no-load operation of the deodorizing apparatus 50 can be prevented. In this case, by setting the time t ₂ for accommodating the material to be dried is completed, energization of the deodorizing heater 53 is started at the timing B _2.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In addition to the U-shaped (S-shaped) trap illustrated in the first embodiment, the trap section provided in the drain pipe of the dripping water from the cooler is configured by configuring a part of the trap path with a lid. Other types of traps may be employed, such as a trap with a lid that allows the interior to be cleaned by removing the lid.
(2) As means for hermetically closing the internal drain pipe, other means such as providing a manual on-off valve may be taken.
(3) Some models are not equipped with an in-chamber drain, and the present invention can be applied to such a type.

(4) The combustion type deodorization device is not limited to the one exemplified in the above embodiment, but may be of other types having different structures, combustion decomposition temperatures, and the like.
(5) Further, the deodorizing apparatus is not equipped with a heater for heating the catalyst itself, and is a type in which circulating air is heated in front of the catalyst or the catalyst is heated by oxidative decomposition on the catalyst. Also good.
(6) Furthermore, the present invention is equipped with a cooler and a circulation fan in a cooler room provided in a part of the ceiling or the like in the main body, and the circulation air is operated to pass the air in the warehouse through the cooler room. Then, while being circulated in the main body, it can be similarly applied to a drying apparatus of a type that generates dehumidified air by passing through a cooler.

Sectional drawing which shows the internal structure of the drying apparatus which concerns on Embodiment 1 of this invention. II-II sectional view of FIG. Schematic diagram of combustion deodorizer Drying timing chart Graph showing protease activity in edible edible parts Graph showing the amount of free amino acids in edible edible parts Graph showing chromaticity of edible edible part Sectional drawing of the drying apparatus which concerns on Embodiment 2. FIG. Sectional drawing of the drying apparatus which concerns on Embodiment 3. Timing chart of drying operation according to Embodiment 4

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Main body 10A ... Front opening 11 ... Inner box 14 ... Door 15 ... Packing (sealing means) 17A-17C ... Ventilation path 18 ... Inlet (outlet) 19 ... Outlet (outlet) 22 ...
Circulating fan 32 ... Cooler 37 ... Bypass path 40 ... Drain pan 43 ... Drain pipe 44
... Trap part (closing means) 50 ... Deodorizing device 52 ... Metal honeycomb catalyst (deodorizing catalyst)
53 ... Deodorizing heater (heater) 58 ... Inside drain pipe (inside drain outlet) 60 ... Plug body 65 ...
Solenoid open / close valve (closing means) 67 ... Pressure relief valve (closing means)

Claims (9)

A main body with a front opening made of a heat-insulated box, a door attached to the front opening of the main body so as to be opened and closed,
A circulation fan that circulates air in one direction in the main body, a cooler that is connected to a refrigeration apparatus and provided in the circulation path of the air, and a drain pan that receives dripping water from the cooler A drying apparatus having a drain pipe for discharging water to the outside,
An oxidation-type deodorizing device provided in the circulation path with an oxidation catalyst;
Sealing means provided on the door and capable of hermetically closing the door;
Closing means capable of closing the drain pipe is provided,
A drying apparatus characterized in that the inside air is circulated through the deodorizing apparatus in a state where the inside of the main body is hermetically blocked from outside by the sealing means and the closing means. A main body with a front opening made of a heat-insulated box, a door attached to the front opening of the main body so as to be opened and closed,
An inner box that is stored in the main body with a space between the inner surface and a vent is formed on the side surface, a ventilation path that is formed around the inner box, and a ventilation path that is provided around the inner box. A circulation fan that circulates and circulates air in one direction from the ventilation path to the inside of the inner box by the operation, a bypass path provided on a side of the ventilation path, and a refrigeration apparatus are provided in the bypass path. A drying device comprising a cooler and a drain pipe connected to a drain pan that receives dripped water from the cooler and discharging the dripped water to the outside;
An oxidation-type deodorizing device provided with an oxidation catalyst in the ventilation path;
Sealing means provided on the door and capable of hermetically closing the door;
Closing means capable of closing the drain pipe is provided,
A drying apparatus characterized in that the inside air is circulated through the deodorizing apparatus in a state where the inside of the main body is hermetically blocked from outside by the sealing means and the closing means. The drying apparatus according to claim 1 or 2, wherein the deodorizing apparatus includes a heater that heats the oxidation catalyst. The interior wall outlet is opened in the bottom wall of the main body, and a plug for closing the interior drain outlet in an airtight manner is provided. The drying apparatus as described. The drying apparatus according to any one of claims 1 to 4, wherein the closing means is a trap portion formed in the drain pipe. The drying apparatus according to any one of claims 1 to 4, wherein the closing means is an electromagnetic on-off valve provided in the drain pipe. The drying device according to any one of claims 1 to 4, wherein the closing means is a pressure relief valve that closes when the weight of the accumulated water exceeds a predetermined level and opens and drains. . The drying apparatus according to claim 5, wherein the cooling temperature of the cooler is maintained at 0 ° C. or higher by operating the refrigeration apparatus. 6. The drying apparatus according to claim 5, further comprising a control unit that allows energization of the heater of the deodorizing apparatus only after a predetermined time has elapsed after the start of the refrigeration apparatus.

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