JP5009343B2 - Dryer drying control method - Google Patents

Description

  The present invention relates to a drying control method for a dryer used for drying agricultural and marine products and processed products.

  Conventional general agricultural and marine products (shiitake mushrooms, salmon, vegetables, small fish, etc.) dryers are equipped with multiple rows of shelves in a drying chamber, and a drying tray (generally called “shrimp”) that arranges dried foods appropriately. Are moved to the drying chamber and hung on the shelves in each row. The hot air sent to the lower part of the drying chamber by the hot air generator on the side of the drying chamber is blown up from the lower tray to the upper tray, and is discharged to the outside through the exhaust port or circulation port while drying the dry matter on the tray. Or returned to the hot air generator. From the air supply port, fresh external air is taken into the hot air generator by a blower. For example, Patent Literature 1 discloses a shiitake dryer used for drying shiitake mushrooms.

Japanese Patent Laid-Open No. 2-89984

  However, the above-mentioned conventional shiitake dryer adjusts the discharge amount of hot air and the intake amount of outside air by the first adjustment damper and the second adjustment damper, but according to the drying process of dry matter such as shiitake mushrooms. No specific drying control method is disclosed.

  Regarding drying control, the drying temperature (dry bulb temperature at the hot air outlet) is changed manually (in a stepwise manner) by a heat source such as a burner or by a timer. On the other hand, with regard to the exhaust volume, the user adjusts the intake air amount and the exhaust air amount according to the situation while visually observing the dry state of the dry matter, and recently, it is driven by adjusting the opening degree of the intake-exhaust damper. There is a timer control system type (semi-automatic type) combined with a motor, etc., but in any case, it requires an operation for adjusting the drying according to the dry matter state, and it is complicated and labor-intensive for the user (especially at night). It was a work burden.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a drying control method for a dryer that realizes optimal drying control according to each stage of the drying process of dried food such as shiitake mushrooms.

In order to solve the above-mentioned problems, a drying control method for a dryer according to claim 1 of the present invention includes an intake port provided with an intake damper at an upper portion of a hot air generator and a hot air outlet at a lower portion thereof. In addition to opening an exhaust port with an exhaust damper at the upper part of the casing, a hot air introduction port facing the hot air outlet at the lower part of the side wall of the casing and a hot air return port facing the hot air circulation port on the hot air generator side are opened at the upper part, respectively. The hot air introduced from the hot air outlet of the hot air generator to the lower part of the drying chamber through the hot air inlet is blown up in the drying chamber to dry the dry matter arranged in a drying tray housed in a multistage shelf in the drying chamber. In the machine
Based on the detection signal of the relative humidity detection sensor installed near the exhaust port at the top of the drying chamber, the opening amount of the intake damper and exhaust damper is maximized at the initial stage of drying when the relative humidity around the exhaust port exceeds 30%. The intake and exhaust ports are fully opened and the hot air circulation port is fully closed. When the relative humidity reaches 30% or less, the intake and exhaust dampers open when the relative humidity reaches 30% or less. When the amount is halved, the intake and exhaust ports are half-opened, the hot air circulation port is half-closed, and when the relative humidity reaches 15%, the opening amounts of the intake and exhaust dampers are each reduced to 1/3. the hot air circulation port 1/3 is closed with the inlet and exhaust ports 1/3 open Te, dried late the relative humidity is 10% or less, its opening amount of the intake damper and exhaust damper And controls so as to fully open the hot air circulation port for respectively in the minimum inlet and exhaust ports together with the fully closed, drying control method of the dryer.

  The detection signal from the relative humidity detection sensor is sent to the control panel, the opening amount of the intake damper is determined based on the detection signal, and the control signal corresponding to the determined opening amount is sent to the drive device of the intake damper, and the intake damper Is driven to have a predetermined opening amount. As for the exhaust damper, a wind pressure damper is used to automatically adjust the exhaust damper opening amount based on the intake air volume and pressure corresponding to the opening amount of the intake damper, and the control signal corresponding to the opening amount of the intake damper Alternatively, the control panel may be sent to the exhaust damper drive device to drive the exhaust damper to a predetermined opening.

  As described above, according to the drying control method of the dryer according to the present invention, the opening amount of the intake damper and the exhaust damper is specified according to each stage of the drying process (early drying stage, middle stage, and late stage) of dried food such as shiitake mushrooms. By controlling the amount of opening, it is possible to realize optimum drying control according to each stage of the drying process (the initial stage, the middle stage, and the latter stage) of the dry matter.

  The best mode for carrying out the present invention will be described with reference to FIGS. In these drawings, 10 is a dryer, 11 is a hot air generator, and 12 is a drying chamber unit.

  As shown in FIGS. 1 to 3, the hot air generating device 11 includes a furnace 15 having a burner 14 in a lower unit of a casing 13, a heat exchanger 16 connected to the furnace 15, and a blower 17 in an upper unit. To do. A control panel 18 and a chimney 19 communicating with the heat exchanger 16 are provided outside. Fresh outside air taken into the hot air generator 11 from the outside air inlet 20 of the upper unit through the air inlet 21 by the blower 17 is heated by the furnace 15 heated by the flame of the burner 14 and the subsequent heat exchanger 16. Then, the dry hot air is introduced into the lower part of the side drying chamber unit 12 from the hot air outlet 22 of the lower unit. An intake damper 23 that adjusts the amount of intake air from the outside air introduction port 20 is attached to the intake port 21.

  The drying chamber unit 12 forms a drying chamber 25 having a single row × multiple tiers (for example, 15 tiers) of shelves 2 inside a box-shaped casing 24, and a single row × multiple tiers of shelves 2 for drying a large number of sheets. The tray 3 can be accommodated. Further, a moving wheel 26 is provided at the bottom of the box-shaped casing 24 so that the drying chamber unit 12 can be fixed on the hot air generator 11 or moved on the rail 27 to a coupling position. A door 29 for sealing the drying chamber 25 is attached to the loading / unloading port 28 of the drying tray 3.

  A hot air inlet 30 that faces the hot air outlet 22 of the hot air generator 11 is opened at the lower portion of the side wall of the casing 24 on the hot air generator 11 side. The hot air inlet 30 is introduced from the hot air generator 11. An air volume adjusting damper 31 for adjusting the air volume of the hot air is attached. A rectifying plate 32 is provided at the lower part of the casing 24 to form a large number of holes 32a while leaving a ventilation space between the bottom surface and the inner surface. This rectifying plate 32 rectifies the hot air introduced into the lower portion of the casing 24 and serves to create a uniform flow in the drying chamber 25.

  An exhaust port 34 having an exhaust damper 33 is opened in the upper ceiling of the casing 24. The exhaust damper 33 is configured to automatically open the exhaust port 34 when receiving an air volume / pressure from below that exceeds a set value, and to fully close the exhaust port 34 at an air volume / pressure below the set value. A hot air return port 36 that faces the hot air circulation port 35 of the hot air generator 11 is formed in the upper portion of the side wall of the casing 24 on the hot air generator 11 side.

  On the other hand, a hot air branch 37 that faces the hot air inlet 30 of the subsequent drying chamber unit 12 is opened in the lower portion of the side wall of the casing 24 opposite to the hot air generator 11. A shut-off damper (opening / closing damper) 38 for shutting off the branch supply and directing hot air upward is attached. Similarly, a hot air junction 39 facing the hot air return port 36 of the subsequent drying chamber unit 12 is opened on the side wall of the casing 24 opposite to the hot air generator 11, and the hot air junction 39 is also blocked. A damper (open / close damper) 40 is attached.

  Between the hot air generator 11 and the head drying chamber unit 12, the area between the hot air outlet 22 at the bottom of the hot air generator 11 and the hot air inlet 30 at the bottom of the drying chamber unit 12, and the hot air at the top of the hot air generator 11. Annular seals 41 and 41 are attached to seal the circumference between the circulation port 35 and the hot air return port 36 above the drying chamber unit 12. Similarly, between the leading drying chamber unit 12 and the succeeding drying chamber unit 12, there is a space between the hot air branch port 37 below the leading drying chamber unit 12 and the hot air inlet 30 below the succeeding drying chamber unit 12. Annular sealing materials 41 and 41 are attached to seal the surroundings, between the hot air confluence 39 in the upper part of the top drying chamber unit 12 and the hot air return port 36 in the upper part of the subsequent drying chamber unit 12. For example, the annular sealing members 41 may be attached only to the hot air introduction port 30 and the hot air return port 36 of each drying chamber unit 12.

  Detachable metal fittings 42 for easily fixing or connecting the drying chamber unit 12 to the hot air generating device 11 are respectively attached to the upper and lower side walls of the drying chamber unit 12 on the hot air generating device 11 side. The detachable metal fitting 42 is configured to be fixed or connected by hooking the metal fitting main body 43 to the hook portion 44 on the hot air generator 11 side by lever operation, and can be released from the fixed or connected state by lever operation. . Further, hooking portions 44 that are hooked to the metal fitting body 43 of the detachable fitting 42 of the subsequent drying chamber unit 12 are also provided on the upper and lower portions of the side wall of the drying chamber unit 12 opposite to the hot air generator 11. Yes.

  A dry bulb thermometer 45 is installed near the hot air outlet 22 of the hot air generator 11 to measure the drying temperature. A relative humidity detection sensor 46 is installed near the exhaust port 33 of the drying chamber unit 12 to detect the relative humidity of the exhaust discharged from the exhaust port 33.

  The drying control method of the dryer configured as described above will be described below with reference to FIGS. 4 to 10 by taking shiitake drying as an example.

  When the yield is small and only one drying chamber unit 12 is sufficient, one drying chamber unit 12 is fixed or connected to the hot air generator 11. The drying chamber unit 12 accommodates the drying tray 3 in which shiitake mushrooms are arranged in the drying chamber 25 in advance. The drying chamber unit 12 is moved on the rail 27 in a state where the door 29 is closed, and is fixed or connected to the hot air generating device 11 by the attaching / detaching bracket 42. The hot air branch 37 and the hot air junction 39 of the drying chamber unit 12 are closed by the respective shut-off dampers 38 and 40.

  The drying process of shiitake is roughly divided into early, middle and late stages. Adjust the displacement and drying temperature at each stage.

  In the initial stage of drying, the air supply and exhaust ports are fully opened so that the exhaust amount becomes the maximum amount. As shown in FIG. 4, the opening amount of the intake damper 23 is maximized, the intake port 21 is fully opened, and the hot air circulation port 35 is fully closed. The drying start temperature is 40 to 45 ° C.

  By driving the blower 17, the outside air is taken into the hot-air generator 11 from the outside air inlet 20 through the fully opened inlet 21. Then, the hot air is dried by the furnace 15 and the heat exchanger 16 heated by the flame of the burner 14, passes through the hot air outlet 22 and the hot air inlet 30, and passes from the lower space of the drying chamber unit 12 to the rectifying plate 32. It blows up from the bottom through the hole 32a. Meanwhile, heat is given to shiitake to evaporate the water. The maximum amount of intake air is exhausted from the fully open exhaust port 34 to the outside by opening the ceiling exhaust damper 33 to the maximum. Meanwhile, the relative humidity sensor 46 installed near the exhaust port 34 detects the relative humidity around the exhaust port 34 and sends a detection signal to the control panel 18. As time passes, as shown in the graph of FIG. 10, the relative humidity around the exhaust port 34 decreases smoothly from the initial 90% level.

  When the middle stage of drying is reached and the relative humidity around the exhaust port 34 reaches a set value of 30% or less as shown in the graph of FIG. 10, the control panel 18 is driven based on the detection signal from the relative humidity sensor 46. A control signal is sent to the motor, and as shown in FIG. 5, the opening amount of the intake damper 23 is halved, and the intake port 21 and the hot air circulation port 35 are both opened by half. The exhaust amount from the exhaust port 33 becomes ½, and ½ of the total amount of hot air sent to the drying chamber 25 is taken in from the intake port 31, and ½ circulates through the hot air circulation port 35. The exhaust damper 33 is halved as the wind pressure decreases, and closes the exhaust port 34 half. As a result, only the amount taken from the intake port 21 is exhausted outside the machine. Thereafter, the relative humidity of the exhaust from the exhaust port 34 decreases with time. When the set value reaches 15% or less, based on the detection signal from the relative humidity sensor 46, the control panel 18 sets the intake damper 23 to 1/3 opening.

  In the late drying stage, the air supply and exhaust ports are fully closed, and the air in the machine is fully circulated. When the relative humidity of the exhaust gas from the exhaust port 34 becomes 10% or less, based on the detection signal from the relative humidity sensor 46, the intake damper 23 is set to the minimum opening degree by the control signal from the control panel 18 as shown in FIG. The intake port 21 is fully closed, and the hot air circulation port 35 is fully opened. The wind pressure with respect to the exhaust damper 33 returns below the set pressure, and the exhaust port 34 is fully closed. As a result, almost all the air in the machine circulates. If no change in humidity is observed for 2 to 3 hours thereafter, the drying operation is stopped.

  A series of control operations from the start to the end of drying as described above can be executed by a selection program incorporated in the control panel 18. The user can execute the automatic operation by arbitrarily selecting a program in a dry matter state from a plurality of dry programs prepared. As a selection program, there is a program and small fish for Hiyoko for drying shiitake mushrooms (small shiitake mushrooms that don't get wet in the rain and with little water) and Amiko (it's a big shiitake mushrooms that gets wet in the rain and has a lot of water) Prepare a program for drying.

  Next, when the yield is large and one drying chamber unit 12 is insufficient, the drying chamber unit 12 is added. The succeeding drying chamber unit 12 is fixed to or coupled to the leading drying chamber unit 12 by means of a detachable fitting 42. The hot air branch port 37 and the hot air junction port 39 of the head drying chamber unit 12 are fully opened by depressing the respective shut-off dampers 38 and 40, thereby allowing the drying chamber units 12 and 12 to communicate with each other. On the other hand, the hot air branch port 37 and the hot air junction port 39 of the subsequent drying chamber unit 12 are fully closed by raising the respective shut-off dampers 38 and 40. 7 shows a state in which the air supply / exhaust port is fully opened in the initial stage of drying, FIG. 8 shows a state in which the air supply / exhaust port is half open in the middle of drying, and FIG.

  As shown in each figure, part of the hot air introduced from the hot air generator 11 to the lower part of the head drying chamber unit 12 passes through the hot air branch port 37 and the hot air inlet 30 at the lower part of the subsequent drying chamber unit 12. Then, the water is branched and supplied to the lower space of the subsequent drying chamber unit 12, and the inside of the subsequent drying chamber unit 12 is blown up from the bottom to the top. As a result, the two drying chamber units 12 can be combined and dried efficiently. In the initial stage of drying shown in FIG. 7, the entire amount is discharged from the exhaust port 34 of each drying chamber unit 12 to the outside of the machine, and in the middle stage of drying shown in FIG. 8, the hot air flows through the hot air return port 36 and the hot air circulation port 35. A half of the total amount is circulated with the generator 11. In the later stage of drying shown in FIG.

  Further, by combining the two drying chamber units 12, it is possible to perform drying in accordance with the dry matter state. For example, the first drying chamber unit 12 can be used for a large amount of Moe Shiitake with a large amount of moisture, and the subsequent drying chamber unit 12 can be used for a small amount of Hywa Shiitake with a small amount of water, and these can be dried at the same time.

  For example, when the air volume adjustment damper 31 of the hot air introduction port 30 of the head drying chamber unit 12 is turned down and fully opened, and the air volume adjustment damper 31 of the hot air introduction port 30 of the subsequent drying chamber unit 12 is erected to be half open, It is possible to increase the amount of hot air that blows up the interior of the first drying chamber unit 12 from the bottom to the top, and to reduce the amount of hot air that blows up the interior of the subsequent drying chamber unit 12 from the bottom to the top. In this manner, by adjusting the air volume in each drying period (initial stage, middle period, and late stage) in units of units, the dry matter stored in the head drying chamber unit 12 and the dry matter stored in the subsequent drying chamber unit 12 are adjusted. The drying operation based on the optimal air volume adjustment according to the state becomes possible.

  The drying control method for a dryer according to the present invention can be used as a drying control method for dry matter such as shiitake mushrooms.

A longitudinal sectional view showing a dryer used in the drying control method of the present invention, Front view of the dryer shown in FIG. Sectional drawing which follows the AA line of the dryer shown in FIG. The figure which shows the dry operation state by the dry control method of this invention, the figure which shows the initial stage of drying, A diagram showing a drying operation state by the drying control method of the present invention, a diagram showing a middle drying stage, The figure which shows the dry operation state by the dry control method of this invention, the figure which shows the late stage of drying, The figure which shows the dry operation state by the dry control method of this invention, the figure which shows the initial stage of drying, A diagram showing a drying operation state by the drying control method of the present invention, a diagram showing a middle drying stage, The figure which shows the dry operation state by the dry control method of this invention, the figure which shows the late stage of drying, It is a graph which shows the relative humidity of the exhaust port peripheral part from the initial stage of drying to a late stage, the relative humidity of a hot air blower outlet peripheral part, and the relative humidity of a suction port peripheral part.

2 Shelf 3 Drying tray 10 Dryer 11 Hot air generator 12 Drying chamber units 13 and 24 Casing 14 Burner 15 Furnace 16 Heat exchanger 17 Blower 18 Control panel 19 Chimney 20 Outside air inlet 21 Air inlet 22 Hot air outlet 23 Air intake damper 25 Drying room 26 Wheel 27 Rail 28 Drying tray inlet / outlet 29 Door 30 Hot air introduction port 31 Air volume adjustment damper 32 Rectifier plate 32a hole 33 Exhaust damper 34 Exhaust port 35 Hot air circulation port 36 Hot air return port 37 Hot air branch port 38, 40 Shut-off damper (open / close damper)
39 Hot-air junction 41 Annular sealing material 42 Detachable metal fitting 43 Metal fitting body 44 Hook 45 Dry bulb thermometer 46 Relative humidity sensor

Claims (1)

An intake port with an intake damper at the upper part of the hot air generator and a hot air outlet at the lower part of the hot air generator, and an exhaust outlet with an exhaust damper at the upper part of the casing of the drying chamber, and a hot air outlet at the lower part of one side wall of the casing Open the hot air inlet and the hot air return port facing the hot air circulation port on the hot air generator side at the top, and dry the hot air introduced from the hot air outlet of the hot air generator through the hot air inlet to the bottom of the drying chamber. In a dryer that blows up the room and dries dry matter arranged in a drying tray housed in a multi-stage shelf in the drying room,
Based on the detection signal of the relative humidity detection sensor installed near the exhaust port at the top of the drying chamber, the opening amount of the intake damper and exhaust damper is maximized at the initial stage of drying when the relative humidity around the exhaust port exceeds 30%. The intake and exhaust ports are fully opened and the hot air circulation port is fully closed. When the relative humidity reaches 30% or less, the intake and exhaust dampers open when the relative humidity reaches 30% or less. When the amount is halved, the intake and exhaust ports are half-opened, the hot air circulation port is half-closed, and when the relative humidity reaches 15%, the opening amounts of the intake and exhaust dampers are each reduced to 1/3. the hot air circulation port 1/3 is closed with the inlet and exhaust ports 1/3 open Te, dried late the relative humidity is 10% or less, its opening amount of the intake damper and exhaust damper And controls so as to fully open the hot air circulation port for respectively in the minimum inlet and exhaust ports together with the fully closed, drying control method of the dryer.

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