JPS5923768B2 - Heat pump drying method and device for drying shiitake mushrooms - Google Patents

Description

[Detailed Description of the Invention] The present invention involves drying fresh shiitake mushrooms under favorable conditions of appropriate temperature and humidity while activating the action of enzymes, and then further eliminating uneven drying and deactivating enzymes. The present invention relates to a heat pump type shiitake mushroom drying method and apparatus for the purpose of obtaining high quality dried shiitake mushrooms.

As is well known, in order to obtain dried shiitake mushrooms by drying fresh shiitake mushrooms, the drying temperature is set at about 30°C to about 50°C to activate the action of enzymes, and then dried at about 55 to 65°C. It requires a step of inactivating the enzyme, ie, stopping its function, by applying temperature for about 1 hour.

However, according to conventional hot air drying, outside air is introduced and heated to produce hot air, and the water in the raw shiitake mushrooms is evaporated while being blown into the drying chamber, and the hot air is released with water vapor to the outside air for drying. Therefore, if the outside air is highly humid, such as during rainy weather, even if heated, it will not be possible to dry the air at a low temperature of 50℃ or less, resulting in a significant drop in drying efficiency and a drying time of 15 to 18 hours. This required a long period of time, leading to a decrease in work efficiency.

In addition, the outside air conditions change depending on whether it is sunny or rainy or due to changes in climate, so the drying conditions change each time, which can lead to failure in drying. - is required.

The present invention (i) is a method for drying shiitake mushrooms, which has been made to eliminate the above-mentioned drawbacks of the conventional method, and allows obtaining dried shiitake mushrooms of good quality without being affected by changes in weather, and which is easy to handle. and its equipment.

Hereinafter, embodiments of the present invention will be described based on illustrative drawings. As shown in FIGS. 1 and 2, a partition wall 2 is provided in a closed drying chamber 1, and drying materials are stored in communication with each other. A circulation path 4 for the air inside the drying chamber 1 is formed with the section 3, and a heater 5 is attached to the circulation path 4.

A plurality of air-permeable drying shelves 6 made of nets or perforated plates are placed in the vertical direction of the drying material storage section 3, and a circulation blower 7 is attached to the upper or lower part of the drying shelves 6, or both. The structure is such that circulating air can be ventilated from the top to the bottom of the drying shelf 6 or from the bottom to the top.

Reference numeral 8 denotes a heat pump type dehumidifying dryer, and its outlet 9 and suction port 10 are communicated with the upper and lower parts of the drying chamber 1, respectively.

Reference numeral 11 denotes a tray for receiving dehumidified condensed water provided below the evaporator 12 of the heat pump type dehumidifying dryer 8. A drain port 15 is provided at the bottom of the tray 11 and communicates with a water tank 16.

The water tank 16 can be taken out of the drying room 1 at any time.

For example, the heat pump type dehumidifying dryer 8 is
As described in Publication No. 0, a compressor (not shown)
In a refrigeration cycle consisting of an evaporator 12 and a condenser 13, the air inside the drying chamber 1 is sucked in through the suction port 10, and the air is cooled and condensed by the evaporator 12 to dehumidify the moisture taken from the dried material.
The dry air is heated by a condenser 13 and is sent into the drying chamber 1 from an outlet 9 by a blower 14.

The air inside the drying chamber 1 can be controlled at a constant temperature by a thermostat (not shown).

To explain its function based on the above configuration, first, the drying temperature is set to, for example, 40°C by the thermostat.
The heat pump type dehumidifying dryer 8 is operated, and the circulation blower 7 is operated to circulate the air inside the drying chamber 1.

While the air inside the drying chamber 1 is forcibly circulated within the drying chamber 1, a portion of the air is sucked in through the lower suction port 10 of the heat pump type dehumidifying dryer 8, cooled and dehumidified by the evaporator 12, and then the dehumidified air is condensed. The dry air is heated in the container 13 and returned to the drying room 1 through the Suita outlet 9 by the blower 14.

When the temperature inside the drying chamber 1 reaches the set temperature of 40° C., fresh shiitake mushrooms 17 are placed on the drying rack 6 and placed in the drying chamber 1.

After a certain period of time, the fresh shiitake mushrooms 17 are dried to a moisture content close to the desired level.

At this time, the moisture in the fresh shiitake mushrooms 11 evaporates into the dry air, is sucked into the suction port 10, and is drawn into the heat pump type dehumidifying dryer 8.
It is cooled and condensed in the evaporator 12, and becomes condensed water on the tray 1.
1, and further passes through the drain port 15 and is collected and stored in the water tank 16.

Next, the operation of the heat pump type dehumidifying dryer 8 is stopped, and
Activate heater 5.

The air in the drying chamber 1 is heated to approximately 55°C to 65°C by the heater 5 and circulates within the drying chamber 1, but since the heat pump dehumidifying dryer 8 is stopped, it is not dehumidified and remains in a constant humidity state. maintained.

Therefore, as dried shiitake mushrooms come into contact with air of constant humidity and constant temperature, uneven drying will gradually be eliminated, and the
The enzymes that were propagated by the hot air at a temperature of °C are deactivated.

More preferably, the fresh shiitake mushrooms 17 are placed on the drying rack 6 with the caps down and the stalks up, with the folds on the back side of the caps facing upward.

If the folds are facing downward, the spores attached to the folds will fall off during drying, resulting in a decrease in nutritional value.

Furthermore, if the fresh shiitake mushrooms 17 placed as described above are brought into contact with the dry air blown from the top to the bottom by the circulation blower 7, the hot air acts on the underside of the caps of the fresh shiitake mushrooms 17 and the edges thereof. By incorporating just the right amount of ingredients, the shape improves and the product value increases.

In addition, when the heat pump type dehumidifying dryer 8 is stopped and the heater 5 is activated, the circulation blower I is reversed.
When the air inside the drying chamber 1 is circulated and brought into contact with the dried shiitake mushrooms from the bottom to the top of the drying rack 6, the hot air acts on the surface of the dried shiitake mushroom caps, making them glossy, improving their color, and increasing their commercial value. enhance

To summarize as described above, the present invention cools and dehumidifies the air inside the drying chamber 1 using the evaporator 12 of the heat pump type dehumidifying dryer 8, and the dry air heated by the condenser 13 is sent to the drying chamber 1 using the blower 14.
At the same time, the air inside the drying chamber 1 is forcibly circulated by a circulation blower 1 installed in the drying chamber 1, and the enzyme action of the raw shiitake mushrooms 17 housed in the drying chamber 1 is activated. After drying, the operation of the heat pump type dehumidifying dryer 8 is stopped, and the heater 5 installed in the drying room 1 is turned off.
A heat pump method for drying shiitake mushrooms, which is characterized in that, while operating, the circulating fan 7 blows air to eliminate uneven drying of the dried shiitake mushrooms 17 and deactivate enzymes.
In addition, a partition wall 2 is provided in the closed drying chamber 1 to form a drying material storage section 3 and a circulation path 4 for the air inside the drying chamber 1, and the upper and lower portions of each are communicated with each other, and the drying material is A plurality of air-permeable drying shelves 6 are provided in the housing section 3, a heater 5 is provided in the circulation path 4, and a circulation blower 7 is provided that forcibly circulates the air inside the drying chamber 1 to appropriate locations within the drying chamber 1. At the same time, the upper and lower parts of the drying chamber 1 are communicated with the air outlet 9 and the suction port 10 of the dehumidifying dryer 8, respectively, so that the dehumidifying dryer 8 can be operated and the heater 5 can be stopped. This heat pump type shiitake mushroom drying device is characterized in that it is configured so that the operation of the heater 5 can be switched between.

Therefore, according to the present invention, it is possible to create dry air by dehumidifying the air inside the drying chamber 1 while providing a low temperature of about 50°C or less, which is the drying temperature condition required for drying fresh shiitake mushrooms. As a result, drying efficiency can be increased without being affected by the weather.

Further, since the air inside the drying chamber 1 is dried while being dehumidified, dry air with an appropriate temperature and appropriate humidity can be created.

Therefore, the enzymatic action of fresh shiitake mushrooms 17 is actively carried out, and high quality dried shiitake mushrooms with increased flavor and nutritional value can be obtained.

Furthermore, in addition to dehumidifying and drying, as a final drying process, a process is added in which dehumidifying and drying is stopped and air at a constant temperature and humidity is circulated only by heating with the heater 5, so it is possible to eliminate uneven drying of dried shiitake mushrooms. Moreover, at the same time, enzymes can be deactivated, and high-quality dried shiitake mushrooms that can be stored for a long time can be obtained.

Furthermore, the water content in shiitake mushrooms contains a large amount of beneficial extracts, and is used as an anti-cancer agent, a health promoter, etc. According to the present invention, fresh shiitake mushrooms are compressed as in the past, Since the moisture content is not obtained by squeezing out, but drying is performed while dehumidifying, the moisture content can be recovered at the same time as dry shiitake mushrooms, which is a win-win situation.

Moreover, it can be said that the drying method and apparatus thereof are easy to handle, safe, and industrially useful.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view, and FIG. 2 is a longitudinal sectional view taken in the direction of the arrow E in FIG. DESCRIPTION OF SYMBOLS 1...Drying room, 2...Partition wall, 3...Dried material storage section, 4...Circulation path, 5...Heater, 6...Drying shelf, 7...Circulating blower , 8... Heat pump type dehumidifying dryer, 9... Air outlet, 10... Suction port, 11...
... Tray, 12 ... Evaporator, 13 ... Condenser, 1
6...Water tank, 11...Shiitake mushrooms.

Claims (1)

[Claims] 1. The air inside the sealed drying chamber 1 is transferred to a heat pump type dehumidifying dryer 8.
The dry air cooled and dehumidified by the evaporator 12 and heated by the condenser 13 is blown into the drying chamber 1 by the blower 14, and the air inside the drying chamber 1 is forced by the circulation blower 1 installed in the drying chamber 1. After drying the fresh shiitake mushrooms 17 housed in the drying chamber 1 by activating the action of the enzyme, the dehumidifying dryer 8 was stopped, and then placed in the drying chamber 1. This heat pump method for drying shiitake mushrooms is characterized in that indoor air is circulated by a circulating blower 7 while a heater 5 is operated to eliminate uneven drying of dried shiitake mushrooms 11 and to deactivate enzymes. 2. A partition wall 2 is provided in the closed drying chamber 1 to form a drying material storage section 3 and a circulation path 4 for the air inside the drying chamber 1, and the upper and lower parts of each are communicated with each other to accommodate the drying material. A plurality of air-permeable drying shelves 6 are provided in the drying section 3, a heater 5 is arranged in the circulation path 4, and a circulation blower 7 for forcibly circulating the air inside the drying chamber 1 is provided at an appropriate location in the drying chamber 1. At the same time, the upper and lower parts of the drying chamber 1 are connected to the air outlet 9 and the suction port 10 of the dehumidifying dryer 8, respectively, so that the operation of the dehumidifying dryer 8 and the stopping of the heater 5, the stopping of the dehumidifying dryer 8, and the heater are controlled. 5. A heat pump type shiitake mushroom drying device characterized in that it is configured to be switchable between the following operations.