JP5842202B2 - Wood dryer and drying control method thereof - Google Patents

Description

  The present invention relates to a wood dryer used for drying wood and a drying control method thereof.

  As wood is dried, shrinkage of the material, misalignment, warping, cracking, cracks, and the like occur. Therefore, it is necessary to dry the wood that has been sawn after cutting. The moisture content of the wood after felling is 100% or more, and the moisture content is reduced to 20% or less by drying. There are two types of drying of wood: natural drying and artificial drying. Artificial drying is a method of artificially drying wood in a short time using a dryer. Various methods (steam-type drying, steam / high-frequency combined drying, dehumidification) Type drying, smoke drying, high-frequency heating type, etc.). The most common method is steam drying (refer to Patent Document 1 and Patent Document 2) called a high-temperature type. Such steam-type drying involves transporting timber stacked in a drying chamber, supplying steam at a high temperature of around 120 degrees to the drying chamber, circulating it between the stacked timbers, and thereby the surface of the timber. Therefore, drying can be promoted and the wood can be dried in a short time. Moreover, in order to accelerate drying, the drying time is shortened by increasing the air volume and the air speed of the high-temperature steam with a blower.

JP 10-38459 A JP 2001-162604 A

  However, when high-temperature steam is circulated between the timbers stacked in the drying chamber by a blower, there is a difference in the air volume and wind speed between the upper timbers stacked and the lower timbers (upper There is a problem in that drying varies between the upper and lower timbers stacked, and the timbers are slow and the lower ones are fast. The reason is that, as a result of the high-temperature steam descending by circulation on the entrance side of the stacked timber rising as a result of colliding with the bottom surface, a negative pressure space is formed near the upper wood entrance, This is probably because the volume and speed of hot air passing between the upper pieces of wood are small, and the amount of hot air passing between the lower pieces of wood is increased. Furthermore, there is a problem that such a variation in drying becomes larger when the air volume and the air speed by the blower are increased in order to shorten the drying time.

  Furthermore, boilers are usually used as high-temperature steam heat sources, and conversion to alternative fuels to replace conventional heavy oil is required from the viewpoint of energy saving or effective utilization of wood resources.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a wood dryer that can prevent variation in dry quality that has occurred on the upper and lower sides of wood stacked in a drying chamber. Another object of the present invention is to provide a wood dryer that can save energy and effectively use wood resources.

In order to solve the above problems, a wood dryer according to the present invention includes an intake port and an exhaust port in a casing, a hot water generator and a control unit, and can carry stacked wood into the casing. A drying chamber and a heat exchanging unit that generates hot air by exchanging heat between the outside air and / or circulating air introduced from the intake port with the hot water generated by the hot water device . between the hot air inlet of the drying chamber on the outlet side, and rectifying regulating chamber is provided to advance regulating pressure rectification warm air ejected to the drying chamber,
The controller controls a wet bulb temperature operation mode in which the opening degree of the exhaust damper of the exhaust port is proportionally controlled based on a change amount with respect to a set value of the wet bulb temperature in the drying chamber during the drying operation, and the hot water temperature is a set lower limit value. When the temperature is lower than 1, an intermittent timer operation mode is provided in which the exhaust damper of the exhaust port and the intake damper of the intake port are fully opened for a set time .

A wood dryer according to the present invention includes an intake port and an exhaust port in a casing, a hot water generation device and a control unit, a drying chamber in which stacked wood can be carried inside the casing, and an intake port A heat exchange unit for generating hot air by exchanging heat between the outside air and / or circulating air introduced by the blower and the hot water generated by the hot water device, and warm air in the drying chamber on the outlet side of the blower between the inlet rectifying regulating chamber to advance regulating pressure rectification warm air ejected to the drying chamber is provided,
The controller controls a wet bulb temperature operation mode in which the opening degree of the exhaust damper of the exhaust port is proportionally controlled based on a change amount with respect to a set value of the wet bulb temperature in the drying chamber during the drying operation, and the hot water temperature is a set lower limit value. When the temperature is lower than 1, an intermittent timer operation mode is provided in which the exhaust damper of the exhaust port and the intake damper of the intake port are fully opened for a set time .

A drying control method for a wood dryer according to the present invention includes an intake port and an exhaust port in a casing, a hot water generation device and a control unit, and a drying chamber capable of carrying stacked wood in the casing; A heat exchanging unit that exchanges heat between the outside air and / or circulating air introduced from the intake port with the hot water generated by the hot water device to generate hot air, and is provided on the outlet side of the blower. A method for controlling a wood dryer, in which a rectifying and regulating chamber is provided between a hot air inlet and a rectifying and regulating chamber that preliminarily regulates and rectifies hot air discharged into the drying chamber,
During the drying operation, the control unit proportionally controls the opening degree of the exhaust damper at the exhaust port based on the amount of change with respect to the set value of the wet bulb temperature in the drying chamber , and the hot water temperature is below the set lower limit value. The control unit switches to a relative humidity operation mode in which each opening degree of the exhaust damper of the exhaust port and the intake damper of the intake port is proportionally controlled based on a change amount of the relative humidity in the drying chamber .

A drying control method for a wood dryer according to the present invention includes an intake port and an exhaust port in a casing, a hot water generation device and a control unit, and a drying chamber capable of carrying stacked wood in the casing; A heat exchanging unit that exchanges heat between the outside air and / or circulating air introduced from the intake port with the hot water generated by the hot water device to generate hot air, and is provided on the outlet side of the blower. A method for controlling a wood dryer, in which a rectifying and regulating chamber is provided between a hot air inlet and a rectifying and regulating chamber that preliminarily regulates and rectifies hot air discharged into the drying chamber,
During the drying operation, the control unit proportionally controls the opening degree of the exhaust damper at the exhaust port based on the amount of change with respect to the set value of the wet bulb temperature in the drying chamber , and the hot water temperature is below the set lower limit value. The control unit switches to the intermittent timer operation mode in which the exhaust damper of the exhaust port and the intake damper of the intake port are fully opened for a set time .

A drying control method for a wood dryer according to the present invention includes an air inlet and an air outlet in a casing, a control unit, a drying chamber capable of carrying stacked wood in the casing, and a blower from the air inlet. A heat exchange unit that exchanges heat between the outside air and / or circulating air introduced by the above and generates hot air, and the hot air to be discharged into the drying chamber is previously provided between the hot air inlet of the drying chamber on the outlet side of the blower. A method for controlling a wood dryer provided with a rectifying and regulating chamber for regulating and rectifying,
According to the drying program, when the dry bulb temperature, wet bulb temperature, drying time in the drying chamber is set for each process from the initial drying stage to the late drying stage, and the opening degree of the intake damper falls below the set lower limit value, The control unit interrupts the process and switches to a next process jump mode for shifting to the next process .

  As described above, according to the dryer according to the present invention, the rectifying and regulating chamber that regulates and rectifies the warm air flowing into the drying chamber in advance is provided between the outlet of the blower and the warm air inlet of the drying chamber. Therefore, the regulated warm air can be discharged into the drying chamber to obtain an averaged wind speed that is balanced between the stacked timbers, realizing stable drying and preventing variation in drying quality. It has an excellent effect that it can be achieved.

  In addition, since wood pellets and the like can be used as fuel for hot water generation, there is an excellent effect that it is possible to effectively use offcuts generated during lumbering and reduce fuel costs.

  Furthermore, according to the drying control method of the dryer according to the present invention, the opening degree of the intake damper and the exhaust damper is proportionally controlled during the drying operation based on the amount of change with respect to the set value of the wet bulb temperature in the drying chamber. Therefore, the amount of transpiration from the surface of each piece of wood can be properly discharged in the drying room, which makes it possible to obtain dry wood of excellent quality while suppressing the generation of cracks and mold while efficiently drying each piece of wood. There is an excellent effect of being able to.

The 1st Embodiment concerning the present invention is shown, and the side view which carried out the section view of some wood dryers, AA line arrow sectional view of the wood dryer shown in FIG. Side, showing laid wood, The figure which shows the ideal curve of the water reduction rate change based on the saturation curve during drying, (A) is a table showing an example of a wood drying schedule in which the high temperature setting process is not performed, (B) is a table showing an example of a wood drying schedule in which the high temperature setting process is performed, The 2nd Embodiment which concerns on this invention is shown, and is a front sectional view of a wood dryer.

  A first embodiment for carrying out the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 100 denotes a wood dryer according to the present invention.

  First, the structure of the wood dryer 100 will be described. As shown in FIG. 1, a wood dryer (hereinafter referred to as “dryer”) 100 is provided with a hot water generator 110 and a drying chamber unit 120. The hot water generating device 110 and the drying chamber unit 120 are entirely controlled by the control unit 140 for the hot water generating operation and the drying operation.

  The hot water generator 110 includes a hot water boiler 111, a circulation pump 112, and a pipe 113. The hot water boiler 111 generates hot water at 80 ° C. to 100 ° C. using wood chips as fuel. The generated hot water is sent to the heat exchanging unit 129 in the drying chamber unit 120 described later through the pipe 113 by driving the circulation pump 112. The hot water after the heat exchange passes through the pipe 113, is returned to the hot water boiler 111, is heated again, and is sent to the heat exchange unit 129. Hot water boiler 111 and circulation pump 112 are operated by an operation from control unit 140. The temperature of the hot water generated by the hot water boiler 111 is detected by the hot water temperature detector 114 and fed back to the control unit 140. Reference numeral 115 denotes a chimney.

  As shown in FIGS. 1 and 2, the drying chamber unit 120 includes an intake port 122 for introducing outside air into the upper surface 121 a of the casing 121, and an exhaust port 123 for discharging wet air at the lower portion of the side surface 121 b of the casing 121. The intake port 122 is provided with an intake damper 125 whose opening degree is adjusted by a drive motor 124, and the exhaust port 123 is provided with a wind pressure exhaust damper 126 that automatically opens and closes by increasing or decreasing the wind pressure in proportion to the increase or decrease of the intake air amount. ing. The intake damper 125 controls the opening degree proportionally via a drive motor 124 driven by a control relay based on the amount of change in the proportional band with respect to a set value of the wet bulb temperature measured by a wet bulb thermometer 136 described later ( PI control). As a result, the opening degree of the air pressure exhaust damper 126 is proportionally controlled based on the amount of change in the proportional band with respect to the set value of the wet bulb temperature.

  Inside the casing 121, a drying chamber 127 into which the stacked wood 1 can be carried, and outside air and / or circulating air introduced by the blower 128 from the intake port 122 is exchanged with hot water and supplied to the drying chamber 127. The heat exchange part 129 which produces | generates the warm air W to perform is provided. A circulation passage 131 is provided between the upper surface of the casing 121 and the drying chamber 127 to return the hot air after passing through the drying chamber 127 to the blower 128 side by the circulation duct 130. Between the circulation passage 131 and the hot air inlet of the drying chamber 127, a rectifying and regulating chamber 132 for regulating and rectifying the warm air after heat exchange in advance is provided. In the rectifying and regulating chamber 132, a rectifying body 133 including a large number of discharge holes 133 a is disposed on the hot air inlet side of the drying chamber 127. The blower 128 is disposed in the circulation passage 131 downstream of the intake port 122.

  As shown in FIG. 3, a large number of timbers 1 carried into the drying chamber 127 are arranged on the upper surface of the timber mounting table 134 at regular intervals on the left and right sides by the crosspiece member 2, and a large number of timbers 1 at regular intervals in the vertical direction. They are piled up and are carried into the drying chamber 127 for each wood mounting table 134 by a forklift or the like. And as shown in FIG. 2, the warm air W passes the clearance gap S between the upper and lower timber 1 to the front-back direction, and dries each timber 1. FIG.

  The rectifier 133 provided at the hot air inlet of the drying chamber 127 is composed of a perforated plate provided with a number of discharge holes 133a at regular intervals in the vertical direction (stacking direction) and in the horizontal direction. The outside air and / or circulating air sent to the downstream side of the blower 128 in the circulation passage 131 hits the inner surface of the side surface 121b of the casing 121 and descends, collides with the bottom surface 121c of the casing 121, rises, and has a negative pressure near the upper side. A space is formed, and a pressurized space is formed near the lower side. Thus, in the conventional art in which the rectifying body 133 is not present, the air volume and the wind speed of the warm air passing between the upper timbers 1 among the stacked timbers 1 are the air volume of the warm air passing between the lower timbers 1. However, the air volume difference and the wind speed difference are greatly different between the upper and lower woods, and the drying quality varies. However, a large number of discharge holes 133a are formed vertically and horizontally at the hot air inlet of the drying chamber 127. By arranging the rectifying body 133 drilled in the direction, the discharge amount and the discharge air velocity of the hot air discharged from each discharge hole 133a are made uniform in the vertical direction. That is, a rectifying and regulating chamber (preload chamber) 132 is formed on the outlet side of the blower 128, and the wind pressure is made uniform between the upper and lower sides in the rectifying and regulating chamber 132. As a result, all the discharge holes 133a of the rectifying body 133 are simultaneously sent. The warm air, which has been rectified and has a uniform speed and air volume, is discharged into the drying chamber 127.

  The heat exchanging portion 129 includes a large number of heat exchanging housings 129A continuing from the pipe 113, and each heat exchanging housing 129A is provided with a large number of heat exchanging fins (not shown). The heat exchanging unit 129 is disposed in front of the rectifying body 133 (upstream side) in parallel with the rectifying body 133 in the rectifying and regulating chamber 132.

  In the drying chamber 127, a dry bulb thermometer 135 for measuring the drying temperature (warm air temperature) in the drying chamber 127 and a wet bulb thermometer 136 for measuring the wet bulb temperature are arranged near the hot air inlet, respectively. Yes. In addition, guide portions 137 that guide the flow of the circulating air smoothly are provided at the four corners of the inner surface of the casing 121, respectively.

  As described above, the controller 140 feedback-controls the hot water boiler 111 and the circulation pump 112 of the hot water generator 110 based on the hot water temperature from the hot water temperature detector 114. During the drying operation, the hot water boiler 111 and the circulation pump 112 are feedback-controlled based on the dry bulb temperature in the drying chamber 127 to control the temperature of the hot air generated by the heat exchange unit 129 and sent to the drying chamber 127. . Further, the control unit 140 performs optimal adjustment of the intake air amount by the intake damper 125 and the exhaust amount by the exhaust damper 126 based on the wet bulb temperature in the drying chamber 127. More specifically, the opening amount of the intake damper 125 and the opening amount of the exhaust damper 126 are proportionally controlled based on the amount of change in the proportional band with respect to the set value of the wet bulb temperature in the drying chamber 127. Further, the relative humidity is detected based on the temperatures of the dry bulb thermometer 135 and the wet bulb thermometer 136 during the drying operation.

  Next, the usage method and drying control method of the dryer 100 comprised as mentioned above are demonstrated below.

  First, a door (not shown) of the drying chamber unit 120 is opened, and a large number of timbers 1 stacked in a horizontal direction and a vertical direction on the timber mounting table 134 are loaded into the timber mounting table 134 by a forklift or the like, and the door is closed. The wood 1 uses a general structural plate (cedar, no core) as an example here. The moisture content of each timber 1 in the raw wood state is 100% or more, and the moisture content is reduced to 20% or less by a drying operation. The drying operation is performed so that the water content decreases along an ideal curve (hereinafter referred to as “water reduction rate curve”) of the water reduction rate change based on the saturation curve shown in FIG. FIG. 5 (A) shows an example of a basic drying schedule (program) from the state of raw trees. During the drying operation, the dry bulb temperature is initially maintained at 50 ° C., and gradually increased to 55 ° C. and 60 ° C. in the latter half. The wet bulb temperature reduces the initial wet and dry bulb temperature difference, and gradually increases the temperature difference as the moisture content decreases.

  First, in the hot air generator 110, hot water of 80 to 100 ° C. is generated by the hot water boiler 111 by combustion of the wood chip, and the generated hot water is sent to the heat exchange unit 129 through the piping 113 by the circulation pump 112. At the same time, the air in the drying chamber 127 is circulated by the operation of the blower 128. The air sent downstream by the blower 128 is regulated in the rectifying and regulating chamber 132 and is also heat-exchanged with hot water of 80 to 100 ° C. in the heat exchanging section 129 to produce 50 ° C. warm air as the rectifying body 133. Are simultaneously discharged from the discharge holes 132a into the drying chamber 127. It is desirable that the warm air discharge flow rate be a moderate flow rate of 3 m / s or less.

  The warm air discharged into the drying chamber 127 is rectified as a whole, and the air speed and the air volume are made uniform, and passes through the gaps S between the stacked woods 1 at a uniform speed. Taking out moisture from the surface of the water, it leaves the drying chamber 127. At this time, when the wet bulb temperature (detected temperature) by the wet bulb thermometer 136 reaches the upper limit (+ 2 ° C.) of the set temperature proportional band (± 2 ° C.), the control unit 140 fully opens the intake damper 126 ( 100%), and when the wet bulb temperature is at the set temperature, the opening degree of the intake damper 126 is maintained at 50%, and when the wet bulb temperature reaches the lower limit (−2 ° C.) of the proportional band, the intake damper 126 The opening degree of the intake damper 126 is proportionally controlled so that the opening degree is fully closed (0%).

  Since the amount of moisture transpiration is large in the initial stage of drying, the wet bulb temperature changes to a higher value (around 49.5 ° C. or higher) than the set value (47.5 ° C.). Therefore, at the beginning of drying with a large amount of moisture transpiration, the intake damper 126 is fully opened, fresh outside air is introduced into the casing 121, the exhaust damper 127 is fully opened, and moist air is actively discharged from the exhaust port 123. .

  From the initial drying stage to the middle drying stage, the moisture transpiration from the surface of each piece of wood 1 gradually decreases as the moisture content decreases. As a result, the amount of change with respect to the set value of the wet bulb temperature is gradually reduced, and the amount of change in each opening degree of the intake damper 126 and the exhaust damper 127 is also reduced in proportion to the decrease in the change amount. During this time, the moisture content of each wood 1 decreases smoothly. Of the warm air that has passed through the drying chamber 127, the air other than the exhaust air is returned as circulating air to the blower 128 side as circulating air.

  When reaching the late drying stage, the amount of moisture transpiration from the surface of each wood 1 is minimized, and the amount of change with respect to the set value of the wet bulb temperature is also minimized. As described above, the opening degree of the intake damper 126 and the exhaust damper 127 is adjusted based on the amount of change with respect to the set value of the wet bulb temperature in accordance with the amount of moisture transpiration from the surface of each wood 1 from the initial drying stage to the late drying stage. The amount of exhausted moisture can be optimally controlled. In this example, the drying process is completed in 10 days.

  During the drying operation, the hot water sent to the heat exchanging unit 129 is detected by the hot water temperature detector 114. When the hot water temperature falls below the set lower limit temperature (40 ° C.), the control unit 140 The wet bulb temperature operation mode in which the intake damper 126 and the exhaust damper 127 are automatically opened and closed based on the temperature is switched to the relative humidity operation mode in which the intake damper 126 and the exhaust damper 127 are automatically opened and closed based on the relative humidity. The relative humidity is calculated from each temperature of the dry bulb thermometer 135 and the wet bulb thermometer 136.

  In the relative humidity operation mode, the intake damper 126 and the exhaust damper 127 are fully opened when the relative humidity in the drying chamber 127 exceeds a set upper limit value (any value of 70 to 80%). When the hot water temperature falls below the set lower limit temperature (40 ° C.), the hot air temperature decreases (less than 40 ° C.) and the relative humidity in the drying chamber 127 (the relative humidity in the drying chamber during the drying operation is usually 30 to 70%) (The following) rises and reaches 70 to 80%, condensed water is generated in the drying chamber 127, and the drying quality deteriorates. Therefore, in such a case, the operation shifts to the relative humidity operation mode, and when the relative humidity in the drying chamber 127 exceeds the set upper limit value, the intake damper 126 and the exhaust damper 127 are forcibly fully opened, and the relative humidity in the drying chamber 127 is set. Reduce. As a result, when the hot water temperature falls below the set lower limit temperature (40 ° C.), such as when the combustion management of the hot water boiler cannot be performed at night, the control unit 140 automatically switches to the relative humidity operation mode, and the inside of the drying chamber 127 Condensation due to increase in humidity is prevented, and deterioration of dry quality is prevented.

  When the hot water temperature falls below the set lower limit temperature (40 ° C.), the controller 140 automatically opens and closes the intake damper 126 and the exhaust damper 127 based on the intermittent timer from the wet bulb temperature operation mode described above. You may make it switch to mode. In the intermittent timer operation mode, the intake damper 126 and the exhaust damper 127 are fully opened at a set time (5 to 10 minutes per hour), and moisture in the drying chamber 127 is forcibly discharged. Also in this mode, condensation due to an increase in humidity in the drying chamber 127 can be suppressed, and deterioration of the drying quality can be prevented.

  When the opening degree of either the intake damper 126 or the exhaust damper 127 (for example, the intake damper 126) reaches the set lower limit value (for example, about 10 to 20%) during the period from the middle drying stage to the latter drying stage, the next step jump operation is performed. You may make it switch to a mode. In the next process jump operation mode, when the opening degree of the intake damper 126 reaches the set lower limit value without passing the set specified process time, the drying time is shortened by moving to the next process. Can do. When the control unit 140 selects the relative humidity operation mode or the intermittent timer operation mode in the above-described process, the opening degree of either the intake damper 126 or the exhaust damper 127 is set to a lower limit value (for example, 10 to 20). %), Switching to the next step jump operation mode can be stopped.

  The drying temperature (warm air temperature) is set to a medium to low temperature of 50 to 70 ° C., and particularly in the winter season, the drying load tends to increase. In this case, the control unit 140 detects the outside air temperature with the outside air thermometer 138, and when it falls below a set lower limit value (for example, 10 ° C.), the driving amount of the circulation pump 112, that is, the circulation amount of the hot water is increased. Good. In this case, the circulation pump 112 is controlled in rotation speed by an inverter to increase the circulation amount of the hot water, or a bypass valve that bypasses the control valve on the downstream side (feed side) of the circulation pump 112 of the pipe 113 is provided, When the outside air temperature falls below the set lower limit value, the bypass valve may be opened to increase the circulation amount of the hot water. Thus, the amount of heat can be ensured even in the winter as in the summer without reinforcing the heat insulating material in the casing 121 of the wood dryer 100 and increasing the heat transfer area of the heat exchanging portion 129. Equipment costs can be reduced.

  According to the wood dryer 100 of the present embodiment, the rectifying and regulating chamber 132 that regulates the warm air supplied to the drying chamber 127 in advance is provided between the circulation passage 131 and the hot air inlet of the drying chamber 127. The conditioned warm air is blown into the drying chamber 127 from each discharge hole 133a of the rectifier 133, and an averaged wind speed that is balanced between the top and bottom and the left and right of the stacked wood 1 is obtained. It is done. Thus, the warm air with which the wind speed was averaged passes the clearance gap between each timber 1, and stable drying is implement | achieved. That is, there was no variation in dry quality between the upper and lower wood.

  In addition, since the opening degree of the intake damper 125 and the exhaust damper 126 is proportionally controlled based on the amount of change in the proportional band with respect to the set value of the wet bulb temperature in the drying chamber 127, each wood 1 in the drying chamber 127 is controlled. The amount of transpiration from the surface can be appropriately discharged along the ideal curve shown in FIG. 4, that is, the optimum control of the amount of moisture exhausted from the drying chamber 127 can be realized. It is possible to obtain a dry wood of an appropriate quality in which cracking and mold generation are suppressed while efficiently drying the wood.

  When the wood 1 to be carried into the drying chamber 127 is a core holding material, for example, a general structural pillar material (cedar, with core), heat treatment (steamed) so that the raw wood is softened with high-temperature steam in advance. It is desirable to go through a high temperature heat treatment (high temperature set treatment) step. The wood-supported core material carried into the drying chamber 127 tries to shrink due to the dryness of the wood surface, but the wood interior has not yet dried, so there is a risk that the wood surface will be pulled and cracked. is there. Therefore, before carrying into the drying chamber 127, in the high temperature setting process, each wood 1 is steamed with steam at 95 ° C. in a steam kettle to soften the surface, and then the temperature is raised to 120 ° C. to sweat. Promote and dry the surface by rapidly reducing the humidity. Such a high-temperature set treatment can effectively prevent cracking of the cored wood surface.

  FIG. 5B shows an example of an accelerated drying basic schedule (program) of the wood (core holding material) 1 subjected to the high temperature setting process. The wood 1 after the high temperature setting treatment (95 ° C. for 12 hours, 120 ° C. for 12 to 20 hours) has a moisture content reduced to 55% or less, and the dry bulb temperature is a constant temperature of 60 ° C. in the drying chamber 127. The wet bulb temperature is gradually lowered from the initial 50 ° C. to 40 ° C. By carrying out the high temperature setting treatment, the drying step can be completed in about 5 days without cracking the wood surface, and the drying can be completed in about 6 to 7 days even including the high temperature setting treatment.

  In the drying process of wood, the higher the wind speed (warm air speed), the higher the drying speed. However, the influence of the wind speed on the drying speed is large in the first half of the drying, and the influence of the wind speed is small in the second half of the drying. Therefore, the wind speed after the moisture content of 30% in the latter half of the drying is reduced (for example, about 80% or less of the wind speed in the first half, and when the first half is 3 m / s, it is reduced to 1.5 m / s or less). An energy saving operation is possible by controlling the air volume of 128 so as to decrease based on the moisture content measurement of the wood. In this case, the moisture content of wood can be measured by a measuring instrument such as an electric resistance moisture meter, a high frequency moisture meter, or a microwave moisture meter.

  FIG. 6 shows a second embodiment of the present invention, in which a swing flap 150 is added to the outlet side of the rectifier 133 of the dryer 100 ′. In addition, the same code | symbol is attached | subjected to the same member as the member shown in the said embodiment, and the description is abbreviate | omitted.

  The swing flap 150 changes the direction of the warm air discharged from each discharge hole 133a of the rectifying body 133 in the vertical direction. A large number of movable blades 152 that can be turned up and down on the support column 151 support the shaft portion 153. Is attached through. A chain (not shown) is wound around each movable blade 152, for example, around each shaft portion 153. By rotating the motor forward and backward, each movable blade 152 is swung up and down all at once, and each discharge hole 133a of the rectifying body 133 is rotated. The direction of the hot air discharged from can be changed in the vertical direction. Thereby, the nonuniformity of the warm air discharged into the drying chamber 127 can be further eliminated (promoting the homogenization of the warm air is further promoted), and the dry quality of each wood 1 can be made more uniform.

  Thus, according to the wood dryer according to the present invention, the moisture evaporated from the surface of each timber is appropriately discharged out of the drying chamber, and the drying of each timber is efficiently advanced, and at the same time, surface cracks, internal cracks, mold Generation | occurrence | production of this can be suppressed and the high quality dry wood without a drying nonuniformity can be obtained.

  The wood dryer and its drying control method according to the present invention can be used as an apparatus and method for drying wood, and also as an apparatus and method for drying agricultural products, marine products, and the like.

DESCRIPTION OF SYMBOLS 1 Wood 2 Crosspiece member 100 Dryer 110 Hot water production | generation apparatus 111 Hot water boiler 112 Circulation pump 113 Piping 114 Hot water temperature detector 115 Chimney 120 Drying chamber unit 121 Casing 122 Intake port 123 Exhaust port 124 Drive motor 125 Intake damper 126 Exhaust damper 127 Drying Tray 128 Blower 129 Heat exchange section 129A Heat exchange housing 130 Circulation duct 131 Circulation passage 132 Rectification pressure regulation chamber 133 Rectification body 133a Discharge hole 134 Wood mounting table 135 Dry bulb thermometer 136 Wet bulb thermometer 137 Guide section 138 Outside air Thermometer 140 Control unit 150 Swing flap 151 Strut 152 Movable blade 153 Shaft S S Gap between stacked wood

Claims (5)

The casing is provided with an inlet and an outlet, a hot water generator and a control unit, a drying chamber in which the stacked wood can be carried inside the casing, and outside air introduced by a blower from the inlet and / or A heat exchanging unit that generates hot air by exchanging heat between the circulating air and hot water generated by the hot water device ;
Between the hot air inlet of the drying chamber at the outlet side of the blower, and rectifying regulating chamber is provided to advance regulating pressure rectification warm air ejected to the drying chamber,
The controller controls a wet bulb temperature operation mode in which the opening degree of the exhaust damper of the exhaust port is proportionally controlled based on a change amount with respect to a set value of the wet bulb temperature in the drying chamber during the drying operation, and the hot water temperature is a set lower limit value. It has a relative humidity operation mode that proportionally controls the opening degree of the exhaust damper of the exhaust port and the intake damper of the intake port based on the amount of change in the relative humidity in the drying chamber when the temperature falls below Wood dryer. The casing is provided with an inlet and an outlet, a hot water generator and a control unit, a drying chamber in which the stacked wood can be carried inside the casing, and outside air introduced by a blower from the inlet and / or A heat exchanging unit that generates hot air by exchanging heat between the circulating air and hot water generated by the hot water device ;
Between the hot air inlet of the drying chamber at the outlet side of the blower, and rectifying regulating chamber is provided to advance regulating pressure rectification warm air ejected to the drying chamber,
The controller controls a wet bulb temperature operation mode in which the opening degree of the exhaust damper of the exhaust port is proportionally controlled based on a change amount with respect to a set value of the wet bulb temperature in the drying chamber during the drying operation, and the hot water temperature is a set lower limit value. A wood dryer characterized by having an intermittent timer operation mode in which the exhaust damper of the exhaust port and the intake damper of the intake port are fully opened during a set time when the temperature falls below . The casing has an intake port and an exhaust port, a hot water generator and a control unit, a drying chamber in which the stacked wood can be carried inside the casing, and outside air and / or circulating air introduced by a blower from the intake port And a heat exchanger that generates hot air by exchanging heat with the hot water generated by the hot water device, and is discharged into the drying chamber between the hot air inlet of the drying chamber on the outlet side of the blower A method for controlling a wood dryer provided with a rectifying and regulating chamber for regulating and rectifying warm air in advance,
During the drying operation, the control unit proportionally controls the opening degree of the exhaust damper at the exhaust port based on the amount of change with respect to the set value of the wet bulb temperature in the drying chamber , and the hot water temperature is below the set lower limit value. When the wood drying is characterized in that , based on the amount of change in relative humidity in the drying chamber, the control unit switches to a relative humidity operation mode in which each opening degree of the exhaust damper of the exhaust port and the intake damper of the intake port is proportionally controlled. Drying control method of the machine. The casing has an intake port and an exhaust port, a hot water generator and a control unit, a drying chamber in which the stacked wood can be carried inside the casing, and outside air and / or circulating air introduced by a blower from the intake port And a heat exchanger that generates hot air by exchanging heat with the hot water generated by the hot water device, and is discharged into the drying chamber between the hot air inlet of the drying chamber on the outlet side of the blower A method for controlling a wood dryer provided with a rectifying and regulating chamber for regulating and rectifying warm air in advance,
During the drying operation, the control unit proportionally controls the opening degree of the exhaust damper at the exhaust port based on the amount of change with respect to the set value of the wet bulb temperature in the drying chamber , and the hot water temperature is below the set lower limit value. The control unit switches to an intermittent timer operation mode in which the exhaust damper of the exhaust port and the intake damper of the intake port are fully opened for a set time . The casing is equipped with an intake and exhaust port, and a control unit. Inside the casing, heat is exchanged between a drying chamber that can carry stacked wood and outside air and / or circulating air introduced from the intake port by a blower. And a rectifying and regulating chamber that preliminarily regulates and rectifies the warm air discharged into the drying chamber between the outlet of the blower and the warm air inlet of the drying chamber on the outlet side of the blower. A method for controlling a wood dryer ,
According to the drying program, when the dry bulb temperature, wet bulb temperature, drying time in the drying chamber is set for each process from the initial drying stage to the late drying stage, and the opening degree of the intake damper falls below the set lower limit value, A drying control method for a wood dryer , wherein the control unit interrupts the process and switches to a next process jump mode for shifting to the next process .

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