JPH0436583A - Dry control system for grain dryer - Google Patents

Abstract

PURPOSE:To prevent a drop in the quality of grains resultant from continuous defrosting operation for a long time by suspending said defrosting operation and carrying out dry operation through ventilation induced by open air. CONSTITUTION:When frost adheres to a vaporizer 3 during dehumidification and dry operation, the operation mode is switched over to defrosting operation to eliminate the frost so that hot gas may be supplied to the vaporizer 3 from a condenser 4. As a result, the refrigerant temperature rises and the refrigerant temperature resumed. At the same time, an exhaust fan 5 is suspended under control so that defrosting operation may be carried out to eliminate the frost. When the resumption of the refrigerant temperature is not detected within a specified time during this defrosting operation since the defrosting operation starts, or a moisture sensor 6 detects the moisture of grains which exceeds a specified moisture, a dehumidification device 2 will be suspended under control while the exhaust fan 5 is controlled so that it may start its operation simultaneously. Therefore, the grains are dried up by the ventilation of the open air sucked up by the exhaust fan 5.

Description

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

Conventional technology Conventionally, grains in a grain drying chamber are passed through an evaporator and a condenser of a dehumidifying device to obtain dehumidified air at a predetermined temperature and humidity. As the grains flowing down the drying chamber are exposed to the dehumidifying air and being dried, if frost forms on the evaporator during this dehumidifying and drying operation, this frost will be removed. This was a drying control method in which the defrosting operation was performed while the exhaust fan was stopped and the grains were repeatedly circulated at the same time as the defrosting operation was switched to.

Problems to be Solved by the Invention The grains in the grain drying chamber of a grain dryer are passed through an evaporator and a condenser of a dehumidifier, and a dehumidified air having a predetermined temperature and a predetermined humidity is supplied to the drying chamber. The grains flowing down the drying chamber are exposed to the dehumidified air and dried by being sucked and exhausted by the exhaust fan. If frost adheres to the evaporator during this dehumidifying and drying operation, the defrosting operation is performed to remove the frost, and at the same time, the exhaust fan is stopped and the grains are repeatedly circulated. Operation is performed to remove frost.

If this defrosting operation is switched to at night and the outside air temperature is low at night, this defrosting operation will be carried out for a long time, and as a result, ventilation will be stopped and grains will be Because only grain circulation takes place, if the grain moisture content is high, many grains may shed.

Means for Solving the Problems This invention ventilates dehumidified air obtained by passing grains in a grain drying chamber 1 through an evaporator 3 and a condenser 4 of a dehumidifying device 2 to the grain drying chamber 1. While drying is carried out by sucking and exhausting air with the exhaust fan 5, if frost adheres to the evaporator 3 during this drying operation, the defrosting operation is performed to remove this frost, and the hot air is transferred from the condenser 4 to the evaporator 3. In a grain dryer in which gas is supplied to raise the refrigerant temperature, the refrigerant temperature is returned to perform defrosting, and at the same time the exhaust fan 5 is stopped and controlled, the refrigerant temperature is increased at a predetermined time from the start of the defrosting operation. If the return of grain is not detected and the grain moisture detected by the moisture sensor 6 is higher than a predetermined moisture content, the dehumidifier 2 is stopped and controlled to be ventilated and dried by outside air sucked by the exhaust fan 5. The drying control method is characterized by drying.

Effect of the Invention The grains in the grain drying chamber 1 of the grain dryer are dried by dehumidified air at a predetermined temperature and humidity obtained by passing through the evaporator 3 and condenser 4 of the dehumidifier 2. By passing through the chamber 1 and being suctioned and exhausted by the exhaust fan 5, the grains flowing down the drying chamber 1 are exposed to this dehumidified air and dried, and the moisture sensor 6 indicates the same as the finished target moisture content. Drying is stopped when grain moisture is detected. If frost adheres to the evaporator 3 during this dehumidifying and drying operation, the operation is switched to a defrosting operation to remove the frost, hot gas is supplied from the condenser 4 to the evaporator 3, and the refrigerant temperature is increased. At the same time as the lever refrigerant temperature is restored, the exhaust fan 5 is controlled to stop and a defrosting operation is performed to remove frost.

During this dehumidification operation, if the return of the refrigerant temperature is not detected within a predetermined time after the start of this defrosting operation, and if the grain moisture detected by the moisture sensor 6 is higher than the predetermined moisture, the dehumidifier 2 is controlled to stop, and at the same time, the exhaust air ff15
is controlled to start, and the grains are ventilated and dried by the outside air sucked in by the exhaust fan 5.

Effects of the Invention According to this invention, the dehumidifier 2 switches to defrosting operation, and if the refrigerant temperature does not return even if this defrosting operation is continued for a predetermined period of time, or if the grain moisture is higher than a predetermined moisture content, the dehumidifier 2 switches to defrosting operation. The defrosting operation is stopped and the grains are ventilated and dried by outside air, and hot gas is supplied to prevent the defrosting operation from continuing for a long time (this prevents the grains from shedding. This eliminates the occurrence of a large amount of porosity and steaming, which prevents deterioration in the quality of the grains.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

The ward system shows the state in which the dehumidifier 2 is attached to a circulating grain dryer [7] that dries grains.

This dryer 1i17 has a rectangular shape long in the front and back direction and has a machine wall 8.
A transfer gutter 9 rotatably equipped with a transfer spiral and a ceiling plate 10 are provided at the top, and a storage chamber 11 for storing grains is formed below the ceiling plate 10.

Below this storage chamber 11, ventilation chambers 12 on both left and right sides.
Left and right grain drying chambers 1.1 are provided between the air blowing chamber 12 and the ventilation chamber 13 in the center, and at the bottom of this drying chamber 1.1 there is a feeding valve 14.14 that feeds out the grains and allows them to flow down. is rotatably supported.

The lower side of the drying chamber 1.1 is configured to communicate with a grain collecting trough 15 having a rotatably internal transfer spiral.

On the front side of the mechanism 8, the dehumidifier 2 is removably arranged to correspond to the population side of the ventilation chamber 13, and
An operating device 16 is removably attached to the outer surface of the mechanism 8 to start and stop the dehumidifying device 2 and the dryer 7 for each operation of loading, drying, and discharging.

Also, on the back side of the mechanism 8, there are left and right ventilation chambers 12, 12.
An exhaust duct chamber 17 is formed which can communicate with the
The central rear exhaust cylinder 18 is provided with an exhaust fan 5 and an exhaust fan motor 19 for rotationally driving the exhaust fan 5.

Reference numeral 20 is a valve motor configured to rotationally drive the delivery valve 14.14 via a speed reduction mechanism 21.

A supply port for supplying transferred grains into the storage chamber 11 is provided at the center in the longitudinal direction of the bottom plate of the transfer gutter 9, and a supply port for distributing the grains evenly into the storage chamber 11 is provided below the supply port. A grain raising rack 23 provided with a spreading plate 22 is provided outside in front of the machine wall 8, and a belt with a packet conveyor 24 is stretched inside. A dispensing tube 25 is provided between the grain collecting trough 15 and the lower end thereof is provided for communication, and a supply trough 26 is provided between the lower end and the terminal end of the grain collecting trough 15 for communication.

Reference numeral 27 denotes a grain raising machine motor, which includes a belt with the packet conveyor 24, the transfer spiral in the transfer gutter 9, and the spreader plate 22.
etc., and the transfer spiral in the grain collecting trough 15 is driven to rotate via the belt with the packet conveyor 24.

A moisture sensor 6 for detecting grain moisture is provided in the vertically central portion of the elevator machine 23. This moisture sensor 6 is activated by transmitting an electrical measurement signal from the operating device 16.
The moisture motor 28 rotates, and each part of the moisture sensor 6 is driven to rotate to receive the grains that fall while being conveyed to the upper part of the packet conveyor 24, crush the grains under pressure, and at the same time crush the crushed grains. It is configured to detect moisture.

The dehumidifying device 2, which is movable by providing casters on the bottom plate, is equipped with a compressor 29, a condenser 4, an expansion valve 30, and an evaporator 3.
The outside air taken in through the dehumidifier t2 is mixed with the dehumidified air taken into the dehumidifier t2, which is converted into dehumidified air, and this mixed dry air is taken into the ventilation chamber 13. It is structured as follows.

In the dehumidifier 2, in order to convert the outside air supplied into the dehumidifier 2 from the outside air intake port 32 at the front into dehumidified air with low humidity, the low-temperature, low-pressure gas that is the refrigerant is used in the compressor 29. It is adiabatically compressed and converted into a high-temperature, high-pressure gas, which loses heat as it passes through the condenser 4 and changes into a high-temperature, high-pressure liquid, and then becomes a low-temperature, low-pressure gas with no pressure drop when passing through the expansion valve 30. It changes into a liquid, and when it passes through the evaporator 3, it absorbs heat and changes into a low-temperature, low-pressure gas, and this cycle is repeated one after another. Note that 33 is a motor for driving the compression 11129, and 34 is a refrigerant temperature sensor that detects the refrigerant temperature in the evaporator 3 and switches to defrosting operation.

Note that the condition of the outside air sucked into the dehumidifier 2 is as follows:
As it passes through the evaporator section 3, it is cooled and moisture in the air condenses, resulting in low-temperature air with reduced absolute humidity.Then, as it passes through the condenser section 4, it absorbs heat and becomes slightly lower than room temperature. It is configured to obtain high temperature, low dehumidification air.

35 is a three-way switching valve, and this three-way switching valve 35
is activated when switching to defrosting operation, and the hot gas in the condenser 4 is supplied to the evaporator 3 by this activation.

The operating device 16 is box-shaped, and the surface plate of the box has a
A start switch 36 for starting the drying 117 and the dehumidifying device 2, etc. for each operation of loading, drying, and discharging; a stop switch 37 for stopping the drying 117 and the dehumidifying device 2; and a moisture setting switch for setting the finishing moisture of grains depending on the operating position. Mi38. A grain type setting setting 39 and a setting amount setting 40 for setting the temperature and humidity of the dehumidified air depending on the operating position, and a digital display section 41 that alternately digitally displays detected grain moisture, detected drying temperature, remaining drying time, etc. and a monitor display, etc., and an outside air temperature sensor 42 for detecting outside air temperature is installed on the outside of the bottom plate.

Also, inside there is an A-D converter 43 for A-D converting the detected value.
An input circuit 44 into which the converted value converted by this A-D converter 43 is input, an input circuit 45 into which various detected values are input,
A CPU 46 that performs arithmetic and logical operations, comparison operations, etc. on input values input from these input circuits 44 and 45;
It has a built-in drying control device 48 and a timer 49, including an output circuit 47 that receives and outputs various commands from the U46. Incidentally, the setting switches 38, 39.degree. 40 are of a rotary switch type, and a predetermined value and type are set according to the operating position.

The drying control of grains by the drying control device 48 is performed as follows. That is, the operation details of the moisture setting setting 38 are input to the CPU 46, and the finishing target moisture (MS1) of the grain is set based on this input. On the other hand, the grain moisture (MS) detected by the moisture sensor 6 is also
The input detected grain moisture (MS) is compared with the set finishing target moisture (MSI), and if it is detected that the detected grain moisture (MS) does not reach the finishing target moisture (MSI). , each part of the dryer 7 is automatically stopped to finish drying the grains.

Additionally, the drying control device 48 has the following functions. That is, the grain type setting mechanism 39 and the grain amount setting mechanism 4
0 is input to the CPU 46, and from these input values, the temperature (H) and humidity (W) of the dehumidified air generated from the dehumidifier 2, which are set and stored in the CPU 46, are selected. The configuration is such that it is controlled to be the same.

The refrigerant temperature sensor 34 detects the temperature (S) of the refrigerant flowing in the evaporator 3 and inputs it to the CPU 46, and this detected refrigerant temperature (S) and the refrigerant temperature (si) set and stored in the CPU 46 are ), and when this detected refrigerant temperature (S) is detected to be lower than the set stored refrigerant temperature (Sl), it is detected that frost has adhered to the evaporator 3, and the dehumidifying and drying is performed. Operation switches to defrost operation to remove this frost. At the same time as this defrosting operation, the three-way switching valve 35 is operated to supply the hot gas in the condenser 4 into the evaporator 3, raising the refrigerant temperature, and returning the refrigerant temperature. Also, the exhaust fan motor 19 that rotationally drives the exhaust fan 5 is controlled to stop, and the exhaust fan 5 is controlled to stop, but the dryer 7 is controlled to continue operating.

During this defrosting operation, the timer 49 detects the elapsed time (T) from the start of the defrosting operation and inputs it to the CPU 46, and sets this detected elapsed time (T) to the C and P U 46. The stored setting memory elapsed time (T1) is compared, and the detection elapsed time (T) is the setting memory elapsed time (T1).
The above is detected, the detected refrigerant temperature (S) detected by the refrigerant temperature sensor 34 at the time of this detection is lower than the set storage refrigerant temperature (S2), and the detected grain moisture detected by the moisture sensor 6 When (MS) is detected to be equal to or higher than the setting memory grain moisture (MS2) set and stored in the CPU 46, the dehumidifier 2 is controlled to stop based on these detections and the defrosting operation is stopped. At the same time, the exhaust fan motor 19 that rotationally drives the exhaust fan 5 is controlled to restart, the exhaust fan 5 is driven to rotate to suck in outside air, and the dryer 7 is controlled to perform ventilation drying to suck in the outside air. The structure is such that the grains being circulated by the wind are ventilated and dried.

During this ventilation drying operation, when the outside air temperature (TC-) detected by the outside air temperature sensor 42 is higher than the set storage outside air temperature (TCl) set and stored in the CPU 46, by this detection, The dehumidifying device 2 is controlled to restart, and at the same time, the front exhaust fan motor 19 that rotationally drives the exhaust air 415 is controlled to restart, the exhaust fan 5 is stopped, and the ventilation drying operation is stopped. The system is configured to switch to defrosting operation again.

During this defrosting operation, if the detected refrigerant temperature (S) detected by the refrigerant temperature sensor 34 is equal to or higher than the set memory refrigerant temperature (S2), the second defrosting operation is changed to a dehumidifying drying operation due to this detection. It is configured to switch.

Also, during this defrosting operation, the outside air temperature (TC) detected by the outside air temperature sensor 42 is lower than the set storage outside air temperature (Te3) set and stored in the CPU 46, and at the time of this detection, When the grain moisture (MS) detected by the moisture sensor 6 is equal to or higher than the set stored grain moisture (MS2) set and stored in the CPO 46, the dehumidifier 2 is not used due to these detections. It is detected that the temperature is below the limit temperature, and an abnormality is displayed on the display section 41, and as described above, the dehumidifier 2 is controlled to stop, the exhaust fan 5 is controlled to restart, and the dryer 7 is controlled to stop. is subjected to ventilation drying operation control to dry the circulating grains.During this ventilation drying, the moisture sensor 6 is continuously controlled to operate, and the grain moisture (MS) detected by this moisture sensor 6 is controlled as described above. ) is detected to have reached the finishing target moisture content (MSI), each operating part of the dryer 7 is stopped and drying of the grains is completed.

During the defrosting operation and ventilation drying operation, the time detected by the timer 49 is also subtracted, as in the dehumidifying and drying operation.

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

By operating each setting switch 38, 39, 40 of the operating device 16 to a predetermined position and operating the start switch 36 that starts dehumidifying and drying, each part of the grain dryer 7, the dehumidifying device 2, the moisture sensor 6, etc. is started, the temperature and humidity of the dehumidified air generated from this dehumidifying device 2 are selected, and dehumidifying and drying operation is started.

This set dehumidified air is generated from the dehumidifier 2, and this dehumidified air passes from the ventilation chamber 13 through the grain drying chamber 1. 5, the grains stored in the storage chamber 11 are exposed to the dehumidified air and dried while flowing down from the storage chamber 11 into the drying chamber 2.2. 14. At 14, the grain is fed to the lower part and flows down from the collection gutter 15 to the supply gutter 26.
The grains are then transferred and supplied into the grain raising machine 23 by a lower transfer spiral,
The packets are conveyed to the upper part by the conveyor 24 and supplied into the transfer gutter 9 through the dispensing cylinder 25, and from the transfer gutter 9 to the spreading plate 2.
2 by the upper transfer spiral, and this diffusion plate 22
is evenly diffused and reduced into the storage chamber 11, circulated and dried, and the moisture sensor 6 detects the grain moisture content (MSI) that is the same as the finishing target moisture (MSI) set by operating the moisture setting tlT'.
MS), the drying control device 4 of the operating device 16
8, the dryer 7 is automatically stopped and the drying of the grains is stopped.

During this dehumidifying and drying operation, the refrigerant temperature sensor 34 detects the refrigerant temperature (S) flowing in the evaporator 3 of the dehumidifier 2, and this detected refrigerant temperature (S) is lower than or equal to the refrigerant temperature (Sl) stored in the setting memory. When detected, it is detected that frost has adhered to the evaporator 3, and upon this detection, the frost is removed (switched to defrosting operation, and at the same time, the three-way switching valve 35 is switched to the defrosting operation.
operates to supply the hot gas in the condenser 4 to the evaporator 3, and the rotation of the exhaust fan 5 is stopped, and the dryer 7 continues to operate while the grains are being circulated and defrosting operation is started. The elapsed time (T) from the start of defrosting is measured by the timer 49.
, and this detection elapsed time (T) is detected to be equal to or greater than the set memory elapsed time (T1), and the detected refrigerant temperature (S) detected by the refrigerant temperature sensor 34 at the time of this detection is equal to the set memory refrigerant temperature ( S2) The following is detected, and the detected grain moisture (S) detected by the recorded moisture sensor 6 is set to the stored grain moisture (S2).
MS2) When the above conditions are detected, the dehumidifier 2 is controlled to stop and the defrosting operation is stopped, and at the same time, the exhaust fan 5 is controlled to restart, and the exhaust fan 5 blows outside air. is suctioned, and the dryer 7 is operated for ventilation drying to dry the grains.

During defrosting operation, if the refrigerant temperature (S) detected by the refrigerant temperature sensor 34 is higher than the set refrigerant temperature (S2), the defrosting operation is stopped and the dehumidification/drying operation is switched to drying the grains. is dehumidified and dried.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a block diagram, Figs. 2 and 3 are flowcharts, Fig. 4 is an overall side view of the grain dryer, and Fig. 5 is a FIG. 6 is a rear view of a portion of the grain dryer, and FIG. 7 is an enlarged partially cutaway front view of a portion of the grain dryer. Explanation of symbols 1 Grain drying room 2 Dehumidifier evaporator exhaust fan 4 Condenser 6 Moisture sensor

Claims (1)

[Claims] Dehumidifying air obtained by passing the grains in the grain drying chamber 1 through the evaporator 3 and condenser 4 of the dehumidifier 2 is ventilated into the grain drying chamber 1, and is sucked and exhausted by the exhaust fan 5 to dry the grains. If frost adheres to the evaporator 3 during this drying operation, the operation switches to a defrosting operation to remove the frost, and hot gas is supplied from the condenser 4 to the evaporator 3 to raise the refrigerant temperature. In a grain dryer that performs defrosting by restoring the refrigerant temperature, the exhaust fan 5 is stopped and controlled, and the refrigerant temperature is not detected within a predetermined time from the start of the defrosting operation, and the moisture sensor 6 The drying control is characterized in that the dehumidifying device 2 is controlled to stop based on the detection that the grain moisture detected by the grain is higher than a predetermined moisture content, and the drying is controlled to be performed by ventilation drying using outside air sucked by the exhaust fan 5. method.