JPH03113279A - Dry control system for grain dryer - Google Patents

Abstract

PURPOSE:To stabilize a drying reduction rate and finishing time for grains by computing vaporization latent heat from the temperature and humidity of mixed drying air, controlling the open air capacity for mixed dried air based on this vaporization latent heat and the quantity of grains to be dried and drying the grains at a specified drying reduction rate. CONSTITUTION:An air capacity of 0.63m<3>/sec is set and stored in CPU 50 based on the vaporization latent heat of 530kcal/kg computed by CPU 50 and a detection feed grain quantity detected by a feed quantity sensor 45 and the aforesaid air capacity is selected. A rotary speed of an on/off valve motor 34 is controlled so that the degree of opening of an on/off valve 33 for an open air suction port 32 may be kept in an open state of 30. At the same time, the rotary speed of an exhauster motor 7, which drives an exhauster 6 is controlled by the rotary speed set and stored in the CPU 50 so that the open air capacity absorbed from the open air suction port 32 may be controlled, thereby attaining the specified drying reduction rate of 0.2%/hr under drying control.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a drying control method for a grain dryer.

Conventional technology Conventionally, while the grains are repeatedly circulated, the inhaled outside air is converted to low-humidity air by a dehumidifier, and this converted low-humidity air is mixed with the inhaled outside air. This was a drying control method in which a mixed drying air was passed into the drying chamber, and the grains flowing down the drying chamber were exposed to the mixed drying air and dried.

Problems to be Solved by the Invention While the grain is repeatedly circulated through the drying chamber of the grain dryer, the inhaled outside air is converted into low-humidity air by a dehumidifier, and this converted low-humidity air is combined with the inhaled air. The mixed drying air passes through the drying chamber, and the grains flowing down the drying chamber are exposed to the mixed drying air and dried.

By maintaining the volume of mixed drying air at a certain level during this drying operation, it is possible to stabilize the drying loss rate of the grains and to stabilize the finishing time of the grains.

Means for Solving the Problems This invention converts outside air taken in while circulating grains into low-humidity air using a dehumidifier 1, and generates a mixed dry air in which this low-humidity air and the outside air air that is taken in are mixed. In a grain dryer equipped with a drying chamber 2 for ventilation and drying, the latent heat of vaporization is calculated from the temperature and humidity of this mixed drying air, and the mixed drying is performed based on this latent heat of vaporization and the amount of grain to be dried. The drying control method is characterized in that the outside air flow rate is controlled to dry the grains at a predetermined drying loss rate.

Effect of the Invention While the grain is repeatedly circulated through the drying chamber 2 of the grain dryer, the inhaled outside air is converted into low-humidity air by the dehumidifier 1, and the converted low-humidity air is inhaled. The mixed drying air is mixed with outside air, and the mixed drying air crosses and passes through the drying chamber 2, so that the grains flowing down in the drying chamber 2 are exposed to this mixed drying air and dried. .

During this drying process, the temperature and humidity of the mixed drying air that dries the grains are detected, and the latent heat of evaporation is calculated from the detected temperature and humidity. As a result, the amount of outside air taken in from this mixed drying air is controlled to increase or decrease, and the grains are dried by controlling the grains to be dried at a predetermined drying loss rate.

Effects of the Invention According to this invention, the latent heat of evaporation is calculated based on the temperature and humidity of the mixed drying wind that dries the grains, and the outside air taken in by this mixed drying wind is calculated based on the calculated latent heat of evaporation and the amount of grains to be dried. By controlling the air volume, the air volume that contributes to the drying of grains with this mixed drying air of low temperature and low humidity is always controlled to an optimum amount, thereby stabilizing the drying loss rate of grains and The finishing time no longer fluctuates significantly.

Embodiment On the farm side, the mechanism 4 of the grain dryer 3 has a rectangular shape that is long in the front and back direction and consists of front and rear wall plates and left and right wall plates, and the front wall plate has the dehumidifier 1, this dryer 3, and the like. The configuration includes an operating device 5 for starting and stopping the dehumidifying device 1, and an exhaust fan 6 on the rear wall plate, a variable speed exhaust fan motor 7 for driving the exhaust fan 6 in variable speed rotation, and a valve motor. 8
The configuration includes the following.

In the center of the lower part of the mechanism 4, there is provided a grain collecting trough 9 in which a transfer spiral is pivoted in the front-rear direction, and above the grain collecting 9, a drying chamber 2 formed between ventilation mesh plates is arranged in parallel. A feed valve 10 for feeding and flowing grains is pivotally supported in the lower part of each drying chamber 2, and a hot air chamber 11 is formed between the inner sides of each drying chamber 2 and communicated with the dehumidifying device l. Each drying chamber 2 has a configuration in which an exhaust chamber 12 is formed outside the drying chamber 2 and is communicated with the exhaust fan 6, and the valve motor 8 rotates the delivery valve 10 via a speed change mechanism 13. The configuration is as follows.

A storage chamber 14 is formed above each drying chamber 2 and communicated with the storage chamber 14,
A ceiling plate 15 and a transfer gutter 16 in which a transfer spiral is pivotally supported are provided on the upper side of this storage chamber 14, and a supply port for supplying transferred grains into this storage chamber 14 is provided in the center of this transfer gutter 16. A diffusion plate 17 is provided below the mouth to uniformly diffuse and return grains into the storage chamber 14.
On the inner side of the front wall plate forming the storage chamber 14, a plurality of loading amount sensors 45 for detecting the amount of grain loaded into the storage chamber 14 are provided in the vertical direction.

The grain elevating machine 18 is installed in front of the front wall plate, and inside thereof, a packet conveyor 19 belt is stretched between upper and lower pulleys, and a discharging cylinder 20 is provided between the upper end and the starting end of the transfer gutter 16. A supply gutter 21 is provided between the lower end and the terminal end of the grain hoist 18 for communication.
The packet conveyor 1 is moved by a grain hoist motor 22 provided at the top.
9 belt, the transfer spiral in the transfer@16 and the grain gutter 9
The transport spiral within the packet conveyor 19 is rotated through the belt of the packet conveyor 19, and a moisture sensor 23 installed approximately in the center in the vertical direction detects grains that fall while being conveyed to the upper part of the packet conveyor 19. The moisture sensor 23 is configured to detect moisture in the crushed grains at the same time as crushing the second grain under pressure, and each part of the moisture sensor 23 is configured to be rotationally driven by a moisture motor 24 provided inside.

The dehumidifier 1 has a box shape, and the front wall plate of the box body is provided with an inlet 25 for inhaling outside air, and the rear wall plate is provided with an inlet 25 for inhaling outside air into the dehumidifier 1, which is converted into low-humidity air. An air outlet 26 for blowing low-humidity air is provided, and a blower fan 27 is provided in front of this air outlet 26 for sucking outside air and blowing low-humidity air. To convert the refrigerant into wind, the refrigerant is converted from low-temperature, low-pressure gas to high-temperature, high-pressure gas,
A compressor 28 that circulates and converts high-temperature, high-pressure liquid into low-temperature, low-pressure liquid, a compressor motor 29 that rotationally drives this compressor 28, and a condenser 30. It has a configuration in which an expansion valve 35 and an evaporator 31 are provided, and an outside air intake port 32 for sucking outside air is provided on the ceiling plate, and an on-off valve 33 that can be opened and closed is provided in the outside air intake port 32. This opening/closing valve 33 is configured to be opened/closed by forward and reverse rotation of an opening/closing motor 34, and when the opening/closing valve 33 is operated to open the opening/closing valve 33, the outside air intake port 32 is adjusted and controlled to become wider. At the same time as the adjustment control, the rotation speed of the exhaust fan motor 7 is also controlled to increase the rotation speed, and the rotation speed of the exhaust fan 6 is controlled to increase the rotation speed, so that the outside air intake from the outside air intake port 32 is increased. In addition, when the open/close valve 33 is operated in the closed state and the outside air intake port 32 is adjusted and controlled to become narrower, the outside air is reduced, contrary to the above, and the inside of the dehumidifier 1 is The low-humidity air converted by the outside air inlet 32 is mixed with the outside air taken in from the outside air intake port 32 to form a mixed dry air, and this mixed dry air flows into the hot air chamber 11 from the air outlet 26. The air is sucked in by an exhaust fan 6, and a temperature sensor 41 and a humidity sensor 42 for detecting the temperature and humidity of this mixed drying air are provided in the hot air chamber 11.

The operating device 5 has a box shape and has a start switch 36 for starting the drying machine 3 and the dehumidifying device 1 for each operation, and a stop switch for stopping the dryer 3 and the dehumidifying device 1, respectively, on the surface plate of the box. 37. Each temperature setting strainer 38 sets the temperature of the low-humidity air generated from the dehumidifier 1 to a predetermined temperature depending on the operating position of the grain type and loading amount.Manipulates the finishing target moisture content and drying rate of the grain. Moisture settings depending on position 39
, a drying loss rate setting indicator 46, a display window 40 that alternately displays detected grain moisture, remaining drying time, etc., a monitor display, etc. are provided, and a drying control device 43 and a temperature control device 44 are installed inside. It is a set configuration, and each setting hunting 38.39
．． 46 is a rotary switch type, and is configured to set a predetermined numerical value depending on the operating position.

The temperature control device 44 includes an A-D converter 47 that converts detected values detected by the temperature sensor 41 , the humidity sensor 42 , and the filling amount sensor 45 from analog to digital; an input circuit 48 to which the converted values are input; an input circuit 49 to which the operations of the temperature setting control 38 and the drying rate setting control 46 are input; and each of these input circuits 48.49
A CPU 50 that performs arithmetic and logical operations, comparison operations, etc. on various input values input from the CPU 50. This configuration includes an output circuit 51 that receives various commands from the CPU 50 and outputs them.

The drying control device 43 includes an AD converter that converts the detection value detected by the moisture sensor 23 from AD to AD, an input circuit to which the converted value converted by the AD converter 47 is input, and each of the above-mentioned devices. An input circuit into which the operations of the switches 36 and 37 and the moisture setting switch 39 are input, and a CPU 50 that performs arithmetic and logical operations, comparison operations, etc. on various input values input from these input circuits, and commands from the CPU 50. This configuration includes an output circuit 51 that receives and outputs various commands.

The drying stop control by the drying control device 43 is performed as follows. When the moisture setting strainer 39 is operated, this operating position is input to the CPU 50, and the finishing target moisture of the grain is set by this input. , the grain moisture detected by the moisture sensor 23 is input to the CPU 50,
The input detected grain moisture content is compared with the set finishing target moisture content, and when the detected grain moisture content becomes the same as the finishing target moisture content, this drying control device 43 automatically controls the drying machine 3.
The drying rate of the grain is calculated by the CPU 50 from the input detected grain moisture.

The temperature %fJ control and drying control by the temperature control device 44 are performed as described below. When each temperature setting knob 38 is operated, this operating position is input to the CPU 50, and this input causes the dehumidification device to The temperature of the low humidity air generated from the compressor motor 29 is set, and the rotation speed of the compressor motor 29 is controlled so as to reach the set temperature of the low humidity air, and the detected grain drying rate is input. Then, the detected drying rate and the operating position of the drying rate setting switch 46 are determined by the CPU.
50, the drying rate is set by this input value, this set drying rate and the detected drying rate are compared by this CPU 50, and if there is a difference, the drying rate is set to be the same as the set drying rate. The configuration is such that the volume of mixed drying air is controlled as described below.

The temperature of the mixed dry air generated from the dehumidifier 1 is detected by the temperature sensor 41, the humidity is detected by the humidity sensor 42, and these detected temperature and detected humidity are used in the CPtJ50.
The CPU 50 calculates the latent heat of vaporization based on this input value, and for example, the calculated latent heat of vaporization is
30 kcal/kg and the amount of loaded grain detected by the loaded amount sensor 45 are input to the CPU 50, and the detected amount of loaded grain of 3000 kg and the drying rate setting controller 46 are operated. Based on the set drying rate of 0.2%/hr, as shown in Figure 2, the air volume set and stored in the CPU 50 is selected as 0.63 i/sec, and this selected air volume is 0. The rotational speed of the on-off valve motor 34 is set and stored in the CPU 50 so that the opening degree of the on-off valve 33 of the outside air intake port 32 becomes an open state of 30 degrees so that the rotation speed becomes .63 dlsec. Controlled by the rotation speed,
At the same time as this on-off valve 33 is controlled to an open state of 30 degrees, the rotation speed of the exhaust fan motor 7 that rotationally drives the exhaust fan 6 is controlled to the rotation speed set and stored in the 200PU50. The amount of outside air sucked in from the outside air intake port 32 of the mixed drying air is controlled, and drying is controlled to achieve a set drying loss rate of 0.2%/hr.

In addition, FIG. 7 is a diagram showing another embodiment, and as shown in FIG. 3,
A heater 52 is provided inside the dehumidifier 1, and this heater 52
When the dehumidifier 1 starts, the temperature of the set low humidity air generated by the dehumidifier 1 is maintained at a constant temperature by operating the temperature setting knobs 38, and the drying rate setting knob 46 is operated. By inputting the position to the CPU 50,
The configuration is such that the latent heat of vaporization set and stored in the CPU 50 is selected. For example, if the temperature of the mixed drying air set is 20°C and the latent heat of vaporization is 535k a
l/kg g, this latent heat of vaporization is 535
In order to obtain k cal / kg, the CP
According to FIG. 7, which is set and stored in U50, the configuration is such that the humidity of the mixed dry air should be 70%, and the capacity of the dehumidifier 1 is changed in order to maintain this relationship. In other words, the temperature of the mixed drying air and the energization time of the heater 52 may be controlled by the CPU 50, and the open position of the on-off valve 33 of the outside air intake port 32 may be controlled by the CPU 50.
The rotation speed of the on-off valve motor 34 is controlled by the CPU 50, and the volume of outside air sucked through the outside air intake port 32 is controlled, and the drying rate of the grains is stabilized by these controls. good.

Hereinafter, the operation of the above embodiment will be explained.

By operating each setting 38, 38, 39, 46 of the operating device 5 to a predetermined position and operating the start switch 36 to start drying, each part of the grain dryer 3, the dehumidifier 1, and the moisture sensor 23 are controlled. etc., the dehumidifying device 1 generates a mixed drying air that is a mixture of low humidity air and outside air, and this mixed drying air crosses from the hot air chamber 11 to the drying chamber 2 and enters the exhaust chamber 1.
The grains stored in the storage chamber 14 are exposed to the hot air and dried while flowing down from the storage chamber 14 into the drying chamber 2, and are then fed out. The grain is fed out to the lower part by the valve 1O, flows down, is transferred from the inside of the grain collecting trough 9, passes through the feeder 21, and is fed into the grain raising machine 18 by the lower transfer spiral, and is conveyed to the upper part by the packet conveyor 19, and is conveyed to the dumping tube 20. From this transfer gutter 16, it is transferred and supplied onto a diffusion plate 17 by an upper transfer spiral, and by this diffusion plate 17, it is evenly distributed and supplied into the storage chamber 14, and is circulated and dried. When the moisture sensor 23 detects the same grain moisture as the finishing target moisture set by operating the moisture setting switch 39, the drying control device 43 of the operating device 5 automatically controls and automatically stops the dryer 3. do.

During this drying work, the temperature of the mixed drying air generated from the dehumidifier 1 is detected by the temperature sensor 41, the humidity is detected by the humidity sensor 42, and the latent heat of evaporation is calculated from the detected temperature and humidity. Based on the calculated latent heat of evaporation and the amount of dried grains that is pasted in, which is detected by the pasted amount sensor 45, the amount of outside air that is taken in from this mixed drying air is controlled,
The grains are dried at the drying rate set by operating the drying rate setting rope 46.

[Brief explanation of drawings]

The figures show one embodiment of the present invention. Figure 1 is a block diagram, Figure 2 is a diagram of the relationship between the amount of loaded grain, drying loss rate, latent heat of evaporation, and air flow rate, and Figure 3 is a diagram of the relationship between the amount of grain packed and the drying rate, latent heat of evaporation, and air volume. Figure 4 is a cross-sectional view taken along line A-A in Figure 3, Figure 5 is a rear view of a portion of the grain dryer, and Figure 6 is a partial side view of the grain dryer. FIG. 7 is a front view showing another embodiment, and FIG. 7 is a diagram showing the relationship between temperature, humidity, and latent heat of vaporization. In the figure, numeral 1 indicates a dehumidifying device, and 2 indicates a drying chamber. Figure 4

Claims (1)

[Claims] Dehumidifier 1 uses outside air to be sucked in while circulating the grains.
In a grain dryer equipped with a drying chamber 2, which converts the low-humidity air into low-humidity air and mixes this low-humidity air with the inhaled outside air to ventilate and dry the grain, the temperature and humidity of this mixed drying air are Drying characterized by calculating the latent heat of evaporation from , and controlling the outside air volume of the mixed drying air based on the latent heat of evaporation and the amount of grains to be dried to dry the grains at a predetermined drying loss rate. control method.