JPS6313666B2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a method for drying seaweed.

``Prior Art'' When drying seaweed, the temperature and humidity inside the drying room have a great effect on the finished product, and are said to be major factors in determining the quality of the product. In other words, even if the humidity inside the drying room is at the set value (40 to 50%), if the temperature exceeds the allowable temperature (50°C) for normal raw seaweed raw materials, the seaweed cells will wither and deteriorate and lose their luster. It may become dull or discolored. Furthermore, even if the temperature inside the drying room is within the permissible range, if the humidity drops below a certain value, for example around 20-30%, it becomes difficult to peel off the seaweed after drying, causing it to tear and shrink easily, and furthermore, the flavor is lost. On the other hand, it is said that when the humidity exceeds a certain value, for example around 60%, cloudiness occurs and the quality deteriorates significantly, such as loss of luster, and the value of the product decreases. For this reason, various improvements have been proposed, some of which have been put into practical use. For example, as a technical document, Japanese Patent Publication No. 52-42869 describes the first step of drying at a constant rate with hot air at a critical temperature at which raw seaweed will wither and deteriorate, and the raw seaweed is pressed against a heated surface at a temperature lower than the permissible temperature. According to Japanese Patent Publication No. 57-056872, there is a method for drying raw seaweed that combines a second step of drying at a decreasing rate. There is a method of drying seaweed in which the burner of the furnace is turned off, and in Japanese Patent Publication No. 58-58068, there is a method of drying seaweed in which the seaweed is passed through multiple drying chambers connected through ventilation ducts at a relatively low temperature. There is a continuous drying apparatus for drying raw seaweed and the like using drying ventilation.
Generally, as shown in Figure 5, an open type dryer with a top plate made of a net or the like is installed inside the factory, and a humidity sensor is installed inside the factory. A method is adopted in which the humidity inside the dryer is detected and the humidity inside the dryer is adjusted accordingly.

``Problems to be Solved by the Invention'' As described above, conventional seaweed drying methods use a so-called open type dryer whose top plate is made of a net, etc., and blow hot air into the dryer. After applying it to the seaweed, it is discharged outside the factory through a fan inside the factory to dry it, or hot air is circulated again to the dryer through a shielding member installed inside the factory, such as a curtain, to dry it. There are ways to reuse hot air. As this humidity control does not target the inside of the dryer but is based on the humidity inside the factory, it is natural that the humidity inside the dryer will vary depending on the time of day and the weather, resulting in overdrying at times. As mentioned above, there is a problem of tearing and cracking, which leads to deterioration of quality. In addition, the temperature can be controlled relatively easily with the burner of the combustion furnace, the wind speed with the fan, and the time with the conveyor speed.
No suitable means of controlling humidity could be found, and improvements were desired. Furthermore, when the inside of the dryer becomes humid on a rainy day, a dull sheet of seaweed called kumori nori is formed.

Furthermore, the invention of simultaneous application (1), which is on the same track as the present invention, can also maintain a constant humidity state;
Since it is ON and OFF, a constant range will always occur under constant humidity conditions.

``Means for Solving the Problems'' Therefore, the present invention uses a relatively simple method to maintain the humidity of the drying chamber at a set value while controlling the heated, constant humidity air generated in the closed drying chamber. In addition, once the dryer is filled with raw seaweed, the moisture coming out of the raw seaweed will cause the dryer to become humid, so as a general rule, the air inlet should be blocked. The gist of this is that the dryer is equipped with an intake and exhaust port that can be opened and closed by a shutter to form a closed drying chamber, and a humidity sensor and humidifier are installed inside this drying chamber. A fan room controlled by an inverter is installed, and the humidity of the drying room is detected by the humidity sensor,
When the humidity is at the set value, the heated, constant humidity air generated in the drying room is circulated, when the humidity is below the set value, the humidifier is activated, and vice versa. In some cases, a fan is driven via an inverter to open the drying room, and while the humid air in the room is exhausted, outside air or air from inside the factory is introduced to maintain the humidity at the set value. This is a method of drying seaweed that circulates and controls the heated, constant-humidity air that is generated.

"Function" Next, to explain the function of the present invention, raw seaweed is sequentially supplied to the seaweed tank 1 on the supply side, and the combustion furnace 2
The burners are ignited and hot air is sequentially generated. In this case, since the drying chamber 4 is of a closed type, the air generated in the drying chamber 4 is heated, and this heated air is forced through the fan 3 into the drying chamber 4.
It first contacts the fresh seaweed placed in the seaweed cage 1' on the discharge side of the drying chamber 4 and becomes moist air, following the so-called normal normal circulation (hereinafter simply referred to as circulation) path. . This humid air is sent to the combustion furnace 2, where it is heated to become heated air and follows the same process as described above. When the seaweed is dried, it is sequentially discharged from the seaweed basin 1' on the discharge side of the dryer 6.
The following measures are adopted under the following conditions. That is, the humidity sensor 5 detects the humidity in the drying chamber 4, and when the humidity is below the set value, the humidifier 10 is activated to humidify the air to the set value and burn this air while preventing overdrying. The same process as described above is followed by heating in the furnace 2 to create warm, constant humidity air. When the humidity is higher than the set value, the detected value is input to the control circuit 11, and the detected value is converted into an electrical signal via an input converter 12 disposed in the control circuit 11, for example. When the input signal is input to the comparator 14, since the set value has already been input to the comparator 14 via the setting section 13, the input signal of this set value and the input signal of the detected value are compared and the difference is sent to the amplifier 15. The signal is input to the inverter 16, amplified by the amplifier 15, and input to the inverter 16 as a control signal.
Based on this control signal, the inverter 16 converts the frequency, adjusts the rotation speed of the motor 3a based on the converted frequency, makes the rotation of the fan 3 variable, opens the shutter, and blows humid air from the exhaust port 8. In addition to actively exhausting air, outside air or air inside the factory is introduced into the drying chamber 4 through the intake port 9 to reach the set value, and this air is heated in the combustion furnace 2 to heat it and maintain humidity while preventing high humidity and drying. Air it and follow the same process as above. In this way, when the humidity is above the set value, the fan 3 is finely adjusted even for a small detected value to avoid a humid situation and maintain constant humidity air. For example, to explain it concretely using the diagrams in Figures 3 and 4, as shown in Figure 3A, the amount of raw seaweed supplied to the drying chamber 24 immediately after startup is small, but the supply of hot air is now Since this is not sufficient, the humidity inside the dryer 24 depends on the humidity inside the factory and the outside air. The same applies to the present invention, and the humidity in the drying chamber 4 immediately after startup becomes the state shown in FIG. 4A', which corresponds to the humidity in the factory. After that, while the supply of hot air was steady, the supply of raw seaweed continued to dryer 2.
Because it takes time to reach the raw seaweed storage capacity of 4 (the state in which almost all raw seaweed is supplied to the seaweed pond), the humidity decreases and falls below the set value, resulting in the state shown in Figure 3 B, which is called over-drying. becomes. However, in the present invention, as soon as the humidity falls below the set level, the humidity sensor 5 is activated, and the humidifier 10 is activated to humidify and maintain the humidity at the set value. can. In this case, when the raw seaweed is in a hard state, heated, constant-humidity air is first blown into the seaweed tank 1 on the supply side, and this relatively high temperature, constant-humidity air is brought into contact with the hard raw seaweed in reverse circulation. (See Figure 2). This actively softens the hard raw seaweed by heating it at a high temperature and exposing it to constant humidity air, and dries it in a relatively short time. Next, as the supply of fresh seaweed progresses and the dryer 24 is filled, the humidity gradually increases and temporarily maintains the set value, and the temperature also maintains the set value and becomes normal for the time being, as shown in Figure 3 (c). However, since the dryer 24 is conventionally of an open type as described above, it is easily influenced by the outside air or the air inside the factory, and the humidity varies depending on the weather, for example, rainy or sunny. In other words, if it is raining in the morning and sunny in the afternoon, the third
As shown by the one-dot chain line in the figure, since the humidity inside the dryer 24 fluctuated greatly, there was a risk that uneven drying would occur. Also in the present invention, the drying chamber 4 is filled with fresh seaweed, and the humidity is gradually increased to maintain the set value, and the temperature is also maintained at the set value. However, in the present invention, since the drying chamber 4 is a closed type (when the shutter is closed), the temperature and humidity may become high, resulting in humid air (if the temperature becomes too high, turn off the burner). . In principle, it is undesirable for the air to become humid, that is, for the humidity to exceed a set value. The rotation speed of the motor 3a is adjusted based on the frequency, the rotation of the fan 3 is made variable, and the shutter is opened. etc. to lower the humidity to the set value and maintain that value. In this way, when the humidity is above the set value, the fan 3 is finely adjusted even for a small detected value to avoid a humid situation and maintain constant humidity air circulation. Furthermore, if the drying chamber 4 becomes overly dry, the humidifier 10 is operated to humidify and maintain the humidity at the set value as described above. Through such operations, the humidity difference in the drying chamber 4 is reduced as shown in the figure, and the humidity is maintained at almost constant humidity as shown in Figure 4 C'. , it is less affected by outside air, etc., and even if it is affected, it can be maintained at constant humidity by performing the above-mentioned operations. It is thought that the heated, constant humidity air generated in this way activates the activity of water molecules contained in the raw seaweed, allowing the raw seaweed to dry almost uniformly to the center, resulting in high-quality The production of dried seaweed is expected. In this case, when the raw seaweed is in a hard state, heated, constant-humidity air is first blown into the seaweed tank 1 on the supply side, and this relatively high temperature, constant-humidity air is brought into contact with the hard raw seaweed in reverse circulation. (See Figure 2). This actively softens and dries the hard raw seaweed in a relatively short time by heating it at a high temperature and exposing it to constant humidity air.
Then, as the work approaches, the supply of raw seaweed is stopped, so the proportion of raw seaweed in the dryer 24 decreases, and the humidity gradually decreases to below the set value, while the temperature decreases with hot air. Due to the residual heat caused by this, the temperature temporarily rises to a considerably high temperature, resulting in the state shown in Figure 3 (e) where the seaweed cells wither and die. However, in the present invention, as soon as the humidity drops below the set value, the humidity sensor 5 is activated, and the humidifier 10 is activated to humidify and maintain the humidity at the set value. The state shown in Fig. 4, E', is reached. In this case, when the raw seaweed is in a hard state, heated, constant-humidity air is first blown onto the nori basin 1 on the supply side (of course, in this case, no raw seaweed is attached to the nori basin 1 on the supply side), and then Heating became damp and low.
A reverse circulation (see Figure 2) is created in which constant humidity air is brought into contact with hard raw seaweed on the discharge side. As a result, the raw seaweed, which is in a hard state, is desirably slowly dried so that it is actively softened through the slightly moistened, low-temperature, constant-humidity air. Then, as the proportion of raw seaweed in the dryer 24 decreases, the humidity further decreases and becomes considerably lower than the set value, so that the inside of the dryer 24 becomes overdried, as shown in FIG. 3. However, in the present invention, as soon as the proportion of the drying chamber 4 decreases and the humidity drops, the humidity sensor 5 is activated and the humidifier 10 is activated to perform humidification. The state shown in Fig. 4F' is reached in which drying can be avoided. In this case, when the raw nori is hard,
Warmed, constant-humidity air is first blown onto the seaweed cage 1 on the supply side, and a reverse circulation (see Figure 2) is created in which this relatively high-temperature, constant-humidity air is brought into contact with the hard raw seaweed. On the other hand, as a result, the hard raw seaweed is removed from the raw seaweed that has almost completely dried and is attached to the seaweed cage 1' on the discharge side, and the raw seaweed on the supply side is dried and slightly moistened. By applying the heated, constant humidity air that has been lowered by the drying process to the raw seaweed that has almost finished drying, the drying process is slightly more humid than the normal circulation.
It is possible to produce soft dry dried seaweed from the hard fresh seaweed described above.

``Embodiment'' The drawing shows an embodiment of the present invention. Reference numeral 6 indicates a closed type dryer having an intake port 9 and an exhaust port 8 that are opened and closed by a shutter. 4 is configured to open and close by rotating the shutter. In this drying room 4, there are seaweed cages 1 and 1'.
A combustion furnace 2 and a fan 3 are provided. The hot air generated in the combustion furnace 2 passes through the fan 3 and circulates inside the drying chamber 4 in a counterclockwise direction (counterclockwise in FIG. 1) and in a clockwise direction (clockwise in FIG. 2). circulate. That is, the hot air circulates in the reverse direction by the forward rotation of the fan 3, and first comes into contact with the raw seaweed provided in the seaweed cage 1' on the discharge side, and then comes into contact with the raw seaweed provided in the seaweed cage 1 on the supply side, becoming moist air. The humid air reaches the combustion furnace 2 via the fan 3, where it is heated, becomes constant humidity air, and returns to the discharge side seaweed cage 1' counterclockwise. By reversing the rotation of the fan 3, the hot air circulates in the normal direction via the fan 3, and first comes into contact with the raw seaweed provided in the nori pen 1 on the supply side, and then comes into contact with the raw nori provided in the nori pen 1' on the discharge side. This humid air reaches the combustion furnace 2 directly, where it is heated, becomes constant humidity air, and returns to the seaweed cage 1 on the supply side via the fan 3. This circulation method is appropriately selected depending on the structure of the dryer, the temperature and humidity of the outside air, the hardness of the raw seaweed, etc. Reference numeral 5 denotes a humidity sensor installed in the drying chamber 4.
When the detected humidity is below the set value, the humidifier 10 installed in the drying chamber 4 is activated to humidify and maintain the humidity at the set value, and the humidity generated in the closed drying chamber 4 is Circulating and supplying heated, constant humidity air prevents overdrying. Furthermore, when the humidity sensor 5 detects a humidity higher than the set value, the detected value is transferred to the control circuit 1.
1 is input as a control signal to the inverter 16, and based on the frequency converted by the inverter 16, the rotation speed of the fan motor 3a is adjusted, and the rotation of the fan 3 is varied based on the detected value. do. The rotation of the fan 3 rotates the shutter to open the intake and exhaust ports 9 and 8, which opens the drying chamber 4 and exhausts humid indoor air from the exhaust port 8. air and maintain its humidity at the set value. When the set value is reached, the rotation of the fan 3 is stopped, the shutter is rotated to close the intake and exhaust ports 9 and 8, and the drying chamber 4 is closed. Circulate and supply air to prevent low humidity and dryness and high humidity and dryness. The control circuit 11 includes an input converter 12 that converts a detected value from the humidity sensor 5 into an electrical signal,
A comparator 14 that compares the detection value signal inputted from this input converter 12 with a set value signal inputted in advance via the setting section 13, and an amplifier 15 to which the compared difference in this comparator 14 is inputted. It is made up of. In the figure, 17 is a switch. Note that the effects of the present invention have been detailed in the above “effects”, so
I will omit that explanation.

"Effects of the Invention" As described in detail above, the present invention provides a humidity sensor in a closed drying chamber having an intake port and an exhaust port that are opened and closed by a shutter, and a humidifier or a humidifier that operates based on the detection of the humidity sensor. Since a fan is installed and the fan is controlled via an inverter, the humidity inside the drying room can be maintained at approximately the set humidity, making it possible to dry with heated and constant humidity air, avoiding overdrying and drying with too much humidity. . Therefore, it is possible to prevent tears and cracks caused by over-drying, shrinkage and partial wetting caused by insufficient drying, and it is possible to dry almost evenly to the center of raw seaweed.
Uniform drying is achieved and, for example, the color unevenness that is said to occur due to roasting is eliminated, making it possible to obtain dried seaweed that is of good quality and has a long shelf life. Furthermore, since drying is carried out in a sufficiently humidified state, smooth, glossy, and soft dried seaweed can be efficiently produced. In particular, since the rotation speed of the motor is varied via an inverter and the rotation of the fan is adjusted, a constant humidity condition in the drying room can be maintained at all times, making it possible to dry raw seaweed in constant humidity air. Based on this, the aforementioned effects can be expected. In particular, in the present invention, when the raw seaweed is in a hard state, the raw seaweed on the supply side is heated,
Since it has a configuration that applies constant humidity air, so-called reverse circulation, it can effectively deal with raw seaweed in such conditions, and can produce dry seaweed with approximately uniform hardness and a good texture. It is. Furthermore, it is possible to control humidity optimally and according to the situation, depending on the hardness and softness of raw seaweed, and prevents problems such as cracking, partial shrinkage, and tearing caused by overdrying, and reduces defects. The generation of seaweed can be kept to a minimum, and as mentioned above, the air is replaced by an intake port and an exhaust port.
It can supply optimally heated air relatively quickly, and since it is controlled via a fan and an inverter, it is possible to finely adjust the humidity in the drying room, and it also prevents insufficient drying. It is extremely effective in producing high-quality dried seaweed by preventing shrinkage and partial wetting caused by insufficient drying. Furthermore, by controlling in the same way, it is possible to create an optimal humidity environment corresponding to the situation such as raw seaweed and weather conditions.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view, FIG. 2 is a sectional view showing another example, and FIG. 3 is a sectional view showing another example.
Figure 4 is a chart showing the temperature and humidity progress of the conventional device, Figure 4 is a chart showing the temperature and humidity progress of the present invention, Figure 5 is a configuration diagram showing the relationship between the humidity sensor, inverter, and fan, and Figure 6. 1 is a sectional view showing an example of a conventional device. 1, 1'...Seaweed cage, 2...Combustion furnace, 3...Fan, 3a...Motor, 4...Drying room, 5...Humidity sensor, 6...Dryer, 7...Fan, 8...
...Exhaust port, 9...Intake port, 10...Humidifier, 11
... Control circuit, 12 ... Input converter, 13 ... Setting section, 14 ... Comparator, 15 ... Amplifier, 16 ...
...Inverter, 17...Switch.

Claims (1)

[Claims] 1. A dryer is provided with an intake port and an exhaust port that are opened and closed by a shutter to form a closed drying chamber, and a humidity sensor, a humidifier, and a fan controlled by an inverter are installed in this drying chamber, and the above-mentioned A humidity sensor installed in the drying room detects the indoor humidity, and when the humidity is at the set value, either the heated and constant humidity air generated in the drying room is circulated in the normal direction, or the raw seaweed is hardened. In the case of
On the other hand, when the humidity is below the set value, the humidifier in the drying room is activated, and when the humidity is above the set value, the fan is driven via the inverter to open the drying room, causing high humidity in the drying room. Air is exhausted and outside air or factory air is introduced into the drying chamber to maintain the humidity inside the drying chamber at the set value through air replacement.
The heated and constant humidity air generated in the drying room is circulated in the normal direction, or if the raw nori is hard, the heated and constant humidity air generated in the drying room is circulated in the reverse direction. A method of drying seaweed that involves drying raw seaweed.