JPH0593586A - Drying method and drying device - Google Patents

Abstract

PURPOSE:To dry uniformly with high quality and good yield even in case of cedar pillar material which is, high in the initial percentage of moisture content and fluctuation. CONSTITUTION:Cedar pillar materials W are received in the chamber 2 of the main body 1 of a drying house. Air in the chamber 2 is circulated by a circulating fan 3. The temperature and the humidity of the chamber 2 are detected by a temperature and humidity sensor 4. The circulating fan 3 is controlled by an amount of air control device 5 to change the amount of circulating air in the chamber 2 in accordance with the change of temperature in the chamber 2. According to this method, the surface of the cedar pillar material is prevented from excessive drying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying method and a drying apparatus for wood or the like, and more particularly to a drying method capable of uniformly drying a cedar wood having a high initial water content and a large variation with a good yield. And a drying device.

[0002]

2. Description of the Related Art Conventionally, as a drying device for drying wood or the like, as shown in, for example, Japanese Patent Laid-Open No. 62-248986, the moisture content of the material to be dried is increased by raising the temperature in the refrigerator. At the same time, the heat exchange type ventilation fan is operated for a certain period of time to introduce the outside air into the chamber and discharge the moisture to the outside while keeping the temperature inside the chamber constant, and further operate the dehumidifier. By further reducing the humidity in the refrigerator,
It is generally known that the water content of the material to be dried is lowered.

By the way, in this type of drying apparatus, since the outside air is introduced to control the temperature and humidity inside the refrigerator, when the outside air is introduced, the temperature and humidity inside the refrigerator suddenly change, When the material to be dried is wood, cracks in the wood, surface cracks, etc. occur, resulting in poor yield.

Therefore, the inventors of the present invention first disclosed in Japanese Patent Application No. 2-1
No. 5228 proposed a drying device capable of improving the yield of the material to be dried by preventing a rapid change in temperature and humidity in the refrigerator.

[0005]

The drying device proposed by the inventors of the present invention can prevent abrupt changes in temperature and humidity in the refrigerator and improve the yield of the material to be dried. It has the advantage that it can be sufficiently applied to the artificial drying treatment of wood.

However, since the circulating air volume in the refrigerator is kept constant within a predetermined period, when the cedar wood having a high initial water content of 100% or more and a large variation is artificially dried, it is dried. There is a problem that the yield of goods deteriorates.

As a method for improving the yield, it can be considered to reduce the amount of circulating air in the refrigerator, but in this case, there is a problem that the drying treatment period becomes very long and it cannot be put to practical use.

The present invention has been made in view of the present situation, and even when a cedar material having a very high initial water content and a great variation is dried, the quality is uniform, the quality is high and the yield is short. It is an object of the present invention to provide a drying method and a drying device that can be dried with.

Another object of the present invention is to provide a drying method and a drying apparatus capable of shortening the drying treatment time and reducing energy consumption without lowering the yield of the material to be dried. It is in.

[0010]

A drying method according to the present invention is a drying method for lowering the water content of a material to be dried by circulating air in a chamber in which the material to be dried is circulated by an air circulating means. It is characterized in that the humidity in the refrigerator is measured and the circulating air volume in the refrigerator is controlled according to the change in humidity in the refrigerator.

In the drying method according to the present invention, the lower limit of humidity is set, and in the humidity range above the lower limit of humidity, the circulating air volume is changed according to the change in humidity, and
In the humidity range below the lower limit of humidity, it is more preferable to keep the circulating air volume constant.

Further, the drying apparatus according to the present invention comprises a drying cabinet main body for accommodating an article to be dried; an air circulating means for circulating the air inside the cabinet; and a controller for controlling the humidity inside the cabinet based on a signal from a humidity sensor. Wetting means; temperature controlling means for controlling the temperature inside the refrigerator based on a signal from a temperature sensor; air circulation means based on a signal from the humidity sensor, and controlling the circulating air volume in the refrigerator according to a change in humidity And an air volume control means;

In the drying apparatus according to the present invention, the lower limit of humidity is set in the air volume control means, and the air volume control means changes the circulating air volume according to the humidity change in the humidity range above the lower limit of humidity. It is preferable that the air circulating means is controlled so that the air circulating means is controlled so that the circulating air volume becomes constant in the humidity range below the lower limit of humidity.

Further, it is preferable to provide at least one of the humidity control means and the temperature control means with a heating means using hot water from a hot water boiler that uses oil or wood chips as a fuel.

Further, it is more preferable that the operation panel of the air circulation means, the humidity control means, the temperature control means and the air flow control means is installed away from the main body of the drying cabinet so that the respective means can be operated remotely.

[0016]

In the drying method according to the present invention, the amount of circulating air in the refrigerator containing the material to be dried is controlled according to the humidity change in the refrigerator.

By the way, in wood such as cedar whose initial water content is remarkably high, free water occupies a high proportion as a drying mechanism, and how to smoothly perform this is a major problem in the drying process. ing.

That is, in the drying treatment of wood, it is necessary to dry the wood without interrupting the veins of free water movement in the high water content region, but if the surface of the wood has dried, the temporary wood Even if the internal moisture content is high, it becomes very difficult to dry the wood any further.

However, in the drying method according to the present invention, when the humidity in the refrigerator is high, that is, when the moisture content on the surface of the wood is high, a large amount of circulating air is supplied to the wood, while the humidity in the refrigerator becomes low. When the wood comes in, that is, when the surface of the wood begins to dry, the amount of circulating air supplied to the wood becomes small.
For this reason, the wood is dried without interrupting the vein of free water movement, and it is possible to sufficiently pump up the water in the wood to the surface of the wood and perform sufficient drying.

Then, in the drying method according to the present invention,
Set the lower limit of humidity, and in the humidity range above the lower limit of humidity,
By changing the circulating air volume according to the change in humidity and keeping the circulating air volume constant in the humidity range below the humidity lower limit value, it is possible to shorten the drying processing time without lowering the yield of the material to be dried. Becomes

Further, in the drying device according to the present invention,
Based on the signal from the humidity sensor, the air volume control means controls the air circulation means, and the circulation air volume in the refrigerator is controlled according to the humidity change. Therefore, even cedar wood or the like can be dried in a short time in a uniform and high quality with good yield.

Then, in the drying device according to the present invention,
The humidity lower limit value is set in the air volume control means, and in the humidity range in which the humidity lower limit value is exceeded, while controlling the air circulation means by the air volume control means so that the circulating air volume changes according to the humidity change,
In the humidity range below the humidity lower limit value, by controlling the air circulation means by the air volume control means so that the circulating air volume becomes constant, it is possible to shorten the drying treatment time without lowering the yield of the material to be dried. Become.

Further, by providing at least one of the humidity control means and the temperature control means with a heating means using hot water from a hot water boiler that uses oil or wood chips as fuel, wood chips and the like generated during lumber can be effectively used. By using it, it becomes possible to keep the power consumption low.

Further, the operation panel for the air circulation means, the humidity control means, the temperature control means and the air volume control means is installed separately from the drying cabinet main body so that it can be operated remotely, so that it can be dried outdoors. The cabinet body can be operated indoors, such as in an office, and more thorough monitoring is possible.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a wood drying apparatus as an example of a drying apparatus according to the present invention. In the figure, reference numeral 1 is a drying cabinet body in which cedar pillar materials W are stacked in a cabinet 2 via a spacer S. Is. The drying cabinet main body 1 is composed of, for example, a refrigerating container for marine transportation having a door (not shown) at its rear end, and can be freely transported by using a trailer or the like (not shown).

As shown in FIG. 1, a circulation fan 3 for circulating the air in the refrigerator 2 and a temperature / humidity sensor 4 for constantly detecting the temperature and humidity of the refrigerator 2 are provided in the refrigerator body 1. Each is installed. And the circulation fan 3
As shown in FIG. 1, the circulation fan 3 is controlled by frequency control.
Is connected to an air volume control device 5 for controlling the circulation air volume by the air flow rate control device 5 and the temperature / humidity sensor 4
Are connected to operation panels 6 installed indoors such as in offices, and the operation panels 6 enable remote operation and monitoring.

As shown in FIG. 1, the drying cabinet main body 1 is also provided with a temperature and humidity control unit 7 for controlling the temperature and humidity of the interior 2 based on a signal from the temperature and humidity sensor 4. The temperature / humidity adjusting unit 7 is connected to the operation panel 6 via a temperature / humidity controller 8.

As shown in FIG. 1, an oil-fired or wood-fired hot water boiler 9 is connected to the temperature and humidity control unit 7, and the temperature and humidity control unit 7 includes the hot water boiler 9
The temperature of the inside 2 can be controlled by using the warm water from the inside as a heat source. Although not shown in the figure, the temperature / humidity control unit 7 can also control the temperature / humidity of the inside 2 by an electric heater.

Next, the operation of this embodiment will be described.
When drying the cedar pillar material W, first, the inside 2 of the drying cabinet main body 1
Then, the cedar pillar materials W are carried in, and the cedar pillar materials W are stacked in the storage 2 through the spacer S. Then, the interior 2 is closed.

Then, the circulation fan 3 is activated to move the inside 2
The air is circulated, and the temperature and humidity control unit 7 controls the temperature and humidity of the inside 2.

For example, the set temperature of the inside 2 is gradually raised and the set humidity of the inside 2 is gradually lowered according to the drying schedule. As a result, the cedar pillar material W
Is dried without cracking.

By the way, when the humidity in the interior 2 is set to, for example, 70%, the actual humidity in the interior 2 is, for example, approximately + 3% with the set value set, as shown in the upper graph of FIG.
It will change to a waveform between -3%.

In such a case, since the circulating air volume in the interior 2 is conventionally constant, even if the actual humidity in the interior 2 becomes less than the set value and the surface of the cedar pillar material W begins to dry. ,
An excessive amount of circulating air will be supplied to the cedar pillar material W. When an excessive amount of circulating air is supplied, the cedar pillar material W
There is a problem that only the surface of the cedar is dried and the vein of free water movement is cut off, it becomes difficult to dry and remove the water inside the cedar pillar material W, and the uneven distribution of the water causes the cedar pillar material W to crack. ..

Therefore, in this embodiment, the frequency of the circulation fan 3 is controlled by the air volume control device 5, and as shown in the lower graph of FIG. I'm trying to control. That is, when the water content of the surface of the cedar pillar material W is high, and thus the humidity in the chamber 2 is higher than the set value, a large amount of circulating air is supplied to the cedar pillar material W, while the cedar pillar material W When the surface of No. 2 begins to dry and the humidity in the refrigerator 2 falls below the set value, the amount of circulating air supplied to the cedar pillar material W becomes small. Therefore, the cedar pillar material W is dried without interrupting the veins of free water movement, and the water inside the cedar pillar material W can be sufficiently pumped up to the surface to be sufficiently dried.

[0035] Incidentally, the air volume control device 5, the upper limit value 60H _Z is also a lower limit value is set to 40H _Z, circulation fan 3 is controlled within this frequency range. Therefore, even when the humidity of the internal 2 became 73% or more with respect to a set value (e.g. 70%), the circulation fan 3 is constant control at 60H _Z, also humidity-chamber 2, the set value in case it 69% against less, the circulation fan 3 is constant control at 40H _Z. However, by expanding the frequency control range of the circulation fan 3, it is possible to control the circulating air volume of the interior 2 in perfect synchronization with the humidity change in the interior 2.

Here, with respect to the upper limit value, if the range is expanded and the circulating air volume in the compartment 2 is changed in accordance with the change in the humidity in the compartment 2, the humidity in the compartment 2 can be set to the set value more quickly. It is possible to do so, which is preferable.

On the other hand, the lower limit value, the 40H _Z or lower frequency range, the wind speed is extremely lowered, Fanmo - others there may occur problems in durability undergoes hunting, yet a lower limit appropriate It has been confirmed by experiments by the inventors of the present invention that if the value is set to a value, there is almost no fear that the surface of the cedar pillar material W will be excessively dried and cracks will occur. Therefore, it is preferable to set the lower limit value.

Although FIG. 2 shows the case where the humidity change in the compartment 2 and the change in the circulating air flow are completely synchronized,
Since the circulation fan 3 is PID-controlled, the change in the circulating air flow actually changes slightly before the change in humidity.

FIG. 3 is a graph showing the relationship between the frequency change of the circulation fan 3 and time. As is apparent from FIG. 3, in the initial stage of drying, the circulation fan 3 has been controlled in a relatively long time 60H _Z, drying time is less and less controlled by 60H _Z with the progress, dried end In the circulation fan 3, the
It is understood that it is controlled by H _Z.

Since the amount of circulating air in the cabinet 2 is controlled according to the humidity change in the cabinet 2, water on the surface of the cedar pillar material W can be quickly removed and at the same time, the surface of the cedar pillar material W can be removed. Can be prevented from being dried too much so that the vein of free water movement is cut off, and further drying becomes extremely difficult, or cracking occurs. Therefore, a uniform and high quality cedar pillar material W can be obtained with a high yield.

As a heat source for the temperature and humidity control unit 7,
Since the hot water from the hot water boiler 9 is used,
The power consumption can be reduced by using a large number of wood chips existing in a sawmill or oil cheaper than electricity as a fuel. In particular, in the winter when the outside air temperature decreases, a large amount of heat is required to raise the temperature inside the refrigerator 2, so that its practical effect is extremely large.

Since the operation panel 6 can be installed away from the drying cabinet body 1 in an office or the like, it is necessary to go to the installation location of the drying cabinet body 1 each time in order to change conditions or see the progress of drying. It is extremely easy to manage.

In the above-mentioned embodiment, drying of the cedar pillar material W has been described as an example, but it can be applied to other woods, and also to dried objects other than woods.

[0044]

As described above, according to the drying method of the present invention, the circulating air flow rate in the chamber containing the material to be dried is
Since it is controlled according to the humidity change in the refrigerator,
Even when a cedar material or the like having a very high initial water content and a large variation is dried, it can be dried in a short time in a uniform and high quality with a good yield. Moreover, energy saving can be achieved.

Then, in the drying method according to the present invention,
Set the lower limit of humidity, and in the humidity range above the lower limit of humidity,
By changing the circulating air volume according to the humidity change and keeping the circulating air volume constant in the humidity range of the humidity lower limit value or less, it is possible to shorten the drying treatment time without lowering the yield of the material to be dried. ..

Further, in the drying apparatus according to the present invention, based on the signal from the humidity sensor, the air volume control means controls the air circulation means to control the circulation air volume in the refrigerator in accordance with the humidity change. Unlike the case of the conventional air volume constant control, it is possible to obtain a uniform and high-quality dried material with a high yield. Moreover, energy saving can be achieved.

Then, in the drying device according to the present invention,
The humidity lower limit value is set in the air volume control means, and in the humidity range in which the humidity lower limit value is exceeded, while controlling the air circulation means by the air volume control means so that the circulating air volume changes according to the humidity change,
In the humidity range equal to or lower than the lower limit of humidity, by controlling the air circulation means by the air volume control means so that the circulation air volume becomes constant, the drying treatment time can be shortened without lowering the yield of the material to be dried.

Further, by providing at least one of the humidity control means and the temperature control means with a heating means using hot water from a hot water boiler that uses oil or wood chips as fuel, wood chips and the like produced during lumber can be effectively used. It can be used to keep power consumption low.

Further, the operation panel of the air circulating means, the humidity adjusting means, the temperature adjusting means and the air volume controlling means is installed separately from the drying cabinet main body so that the operation panel can be remotely controlled, so that the drying installed outdoors. The cabinet body can be operated indoors, such as in an office, and can be sufficiently managed and monitored.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a drying device according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the humidity change in the refrigerator and the circulating air volume in the refrigerator.

FIG. 3 is a graph showing a frequency change state of a circulation fan during drying of cedar pillar materials.

[Explanation of symbols]

 1 Drying cabinet main body 2 In-chamber 3 Circulation fan 4 Temperature / humidity sensor 5 Air volume control device 6 Operation panel 7 Temperature / humidity control unit 8 Temperature / humidity control device 9 Hot water boiler W Cedar pillar material S Spacer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location F26B 25/22 D 9140-3L H03J 1/00 7341-5K

Claims (6)

[Claims] 1. In a drying method in which air in a refrigerator containing an article to be dried is circulated by an air circulating means to reduce the water content of the article to be dried, the humidity in the oven is measured to measure the humidity in the oven. A drying method characterized in that the amount of circulating air in the refrigerator is controlled according to changes in humidity. 2. A humidity lower limit value is set, and in the humidity range above the humidity lower limit value, the circulating air flow rate is changed according to the humidity change, and in the humidity range below the humidity lower limit value, the circulating air flow rate is constant. The drying method according to claim 1, wherein: 3. A drying cabinet main body for containing an object to be dried; an air circulating means for circulating the air inside the cabinet; a humidity controlling means for controlling the humidity inside the cabinet based on a signal from a humidity sensor; and a temperature sensor. A temperature control means for controlling the temperature inside the refrigerator on the basis of a signal; and an air volume control means for controlling the air circulation means on the basis of the signal from the humidity sensor and controlling the circulating air volume in the refrigerator according to a change in humidity. A drying device characterized by the above. 4. A humidity lower limit value is set in the air volume control means, and the air volume control means is set in a humidity range above the humidity lower limit value.
4. The air circulating means is controlled so that the circulating air quantity changes according to the change in humidity, and the air circulating means is controlled so that the circulating air quantity becomes constant in a humidity range below a humidity lower limit value. Drying device. 5. The at least one of the humidity control means and the temperature control means is provided with a heating means using hot water from a hot water boiler that uses oil or wood chips as a fuel. Or the drying device according to 4. 6. The operation panel for the air circulating means, the humidity adjusting means, the temperature adjusting means, and the air volume controlling means is installed separately from the main body of the drying cabinet and can be remotely operated. 4. The drying device according to 4 or 5.