JPH0427479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a grain drying device that dries grains loaded in a machine body by showering them with hot air supplied by a hot air supply device consisting of a burner device and a blower. This invention relates to improvements in control means for hot air supply devices.

As shown in FIG. 1, the grain dryer A of the above-mentioned form normally transports grains loaded into a grain tank 10 provided in a machine body 1 through a rotary shutter 20, a lower conveyor 21, and an elevator 22. The grains are circulated and flowed by the grain circulation system 2 formed by the upper conveyor 23 and sequentially flow down the flow path next to the air guide path 3 formed by the air-permeable partition wall 30 to generate hot air there. Hot air is blown from the air guide path 3 through the flow path and into the air exhaust port 11 by a hot air sending device a consisting of a burner device 4 and a blower 5 that sends the hot air generated by the burner device to the grains. By feeding the grains in this way, the grains are exposed to hot air and dried. The hot air supply device a, which is composed of the burner device 4 and the blower 5, sets the blower 5 to a desired air flow rate.
The temperature control circuit that controls the operation of the fuel pump of the burner device 4 is controlled by the temperature sensor S1 disposed in the air guide path 3, so that hot air within a certain temperature range is sent to the grains. There is.

By the way, grain dryer A that looks like this
In this case, if the grain loaded in the grain tank 10 in the fuselage 1 has a high moisture content and the moisture easily evaporates, condensation occurs on the inner surface of the machine wall 10a of the grain tank 10 loaded with grain. There is a problem in that the condensation comes into contact with the grains returned to the grain tank 10 in the grain circulation system 2 and wets them, thereby impeding the grain circulation operation.

As a countermeasure for this, in the past, a heat insulating material 10b was provided on the inner or outer side of the machine wall 10a of the grain tank 10, as shown in FIG. 1, to prevent the machine wall 10a from being cooled by the outside air. Although measures have been taken to prevent the occurrence of condensation, this method not only makes it difficult to assemble the body 1 of the grain dryer A, but also
The atmosphere inside the grain tank 10 becomes saturated, leading to concentrated dew condensation in areas where insulation cannot be installed, and the inconvenience of humidifying the grains returned to the grain tank 10. There's a problem.

The present invention was made in order to solve these problems, and an object of the present invention is to provide a new means for effectively preventing dew condensation from forming on the inner surface of the machine wall of a grain tank into which grain is loaded. do.

Therefore, the present invention has been completed based on knowledge obtained through various studies to solve the above-mentioned problems. That is, after repeated research to solve the above-mentioned problem, we found that when dew condensation occurs on the inner surface of the machine wall 10a of the grain tank 10, the hot air sent by the hot air feeding device a passes through the grain layer. It has been found that a large amount of dew condensation also forms around the exhaust port 11 where the air is discharged as exhaust air, and from this, the phenomenon of condensation condensing on the inner surface of the machine wall 10a of the grain tank 10. When the hot air supply device a blows hot air onto the grains, the amount of water vapor that evaporates from the grains is small compared to the amount of wind that carries that water vapor outside, and the evaporated water vapor tends to stagnate inside the machine. I realized that this was caused by
The humidity of the exhaust air discharged to the exhaust port 11 side is 90
When the humidity exceeds % and is close to saturation, the hot air supply device a is controlled so that the amount of air blown by the blower 5 of the hot air supply device a is increased.
The invention was completed based on the result that dew condensation occurring on the inner surface of the machine wall 10a of the aircraft was effectively prevented.

Therefore, in the present invention, as a means for achieving the above-mentioned object, the present invention comprises a burner device that generates hot air, and a blower that blows the hot air generated by the burner device to the grains that are injected into the body of the machine. A hot air supply device of a grain dryer is controlled so that the amount of air blown by the blower increases as the humidity of the exhaust air discharged to the exhaust port side of the machine increases and decreases as the temperature of the exhaust air decreases. A method for controlling a hot air supply device in a grain dryer is proposed,
In addition, as a control device for implementing this control method, a hot air dryer of a grain dryer, which is composed of a burner device that generates hot air and a blower that sends the hot air generated by the burner device to the grains injected into the machine body. In the blower, the blower is equipped with a blower speed control circuit that controls the rotation speed, and the blower speed control circuit is controlled by a humidity sensor installed on the exhaust port side of the airframe when the humidity of the exhaust air increases. This invention proposes a control device for a hot air supply device in a grain dryer, characterized in that the rotation speed of the blower is controlled to decrease as the rotation speed increases and the humidity of the exhaust air decreases.

Next, embodiments will be described in detail with reference to the drawings.

Figure 2 shows a grain dryer A used to carry out the method of the present invention.
In this figure, 1 is the body of the grain dryer A, 10 is a grain tank installed in the machine body 1, and 2 is a rotary shutter 20 installed at the outlet at the bottom of the grain dryer 10. and a grain circulation system consisting of a lower conveyor 21 provided at the bottom of the machine 1, an elevator 22 erected on the outer surface of the machine 1, and an upper conveyor 23 provided at the top of the machine 1; a hot air supply device consisting of a burner device 4 disposed at the entrance of the air guide channel 3 and a suction type blower 5 disposed on the side of the exhaust port 11; S1 is a temperature sensor disposed in the air guide path 3, S2 is a humidity sensor disposed near the exhaust port 11, and 4a is a motor that drives the burner fan of the burner device 4;
4b is a motor that drives the fuel pump P of the burner device 4, 5a is a rotary blade of the blower 5, and 5b is a motor of the blower 5.

The blower 5 of the hot air supply device a is equipped with a blower speed control circuit 50 using an inverter device or the like in the circuit of its motor 5b, as shown in the block circuit diagram of FIG. , a humidity sensor S disposed near the exhaust port 11 of the aircraft body 1
The air blower speed calculation circuit 51 calculates the rotational speed of the air blower 5 based on the output signal sent from the air blower 2.
When the humidity of the exhaust air discharged to the side rises to around 90%, the rotational speed of the blower 5 increases to increase the amount of air blown, and control is performed to reduce the amount of air blown as the humidity decreases. It is designed so that

The burner device 4 also has an air guide path 3 connected to the circuit of the motor 4b of its fuel pump P (or its circuit if the fuel pump P is an electromagnetic pump).
Temperature control circuit 4 that controls the amount of fuel supplied based on the hot air temperature detected by temperature sensor S1 disposed inside.
0 is provided, and under the control of this temperature sensor S1 and the temperature control circuit 40, hot air having a predetermined temperature range set as desired is supplied to the air guide path 3. The temperature control circuit 40 further controls the temperature control circuit 40 in a state where the blower speed calculation circuit 51 performs control to increase the amount of air blown by the blower 5 due to an increase in the humidity of the exhaust air discharged to the air exhaust port 11 as described above. When a signal of excessive humidity continues to be input to the blower speed calculation circuit 51, the blower speed calculation circuit 51 is configured to suppress the operation of the fuel pump P, throttle the amount of fuel supplied, and lower the hot air temperature.
As a result,
When the amount of air blown is increased due to an increase in the humidity of the exhaust air discharged to the air exhaust port 11, the temperature of the hot air is lowered if the humidity still does not decrease.

If the operation of the hot air supply device a of the grain dryer A is controlled using the embodiment device configured as described above, the operation of the hot air supply device a of the grain dryer A can be performed at the beginning of the drying process when drying grains with a high moisture content. When a large amount of water vapor is generated, the humidity of the exhaust air discharged to the exhaust port 11 side increases, and the amount of air blown by the blower 5 increases, increasing the amount of water vapor carried out. Wind humidity decreases.

Therefore, the humidity of the atmosphere on the exhaust side of the machine body 1 decreases, and the phenomenon of condensation in which water vapor condenses on the inner surface of the machine wall 10a of the grain tank 10 is suppressed.

When the humidity is not sufficiently reduced even with an increase in air flow, the amount of fuel burned in the burner device 4 decreases and the temperature of the hot air is lowered to suppress the amount of water vapor generated. This will ensure that the humidity is lowered.

In addition, the air volume of the blower 5 is such that the humidity of the exhaust air is 50%.
By setting the amount to be reduced when the temperature drops to a certain level, the drying efficiency can be improved in the latter half of the drying process, when it becomes difficult for water to evaporate as the drying progresses.

As explained above, in the means of the present invention,
To prevent condensation on the inner surface of the machine wall of the grain tank, which occurs when a large amount of water evaporates from the grain, the blower of the hot air supply device By increasing the amount of air blown, the humidity of the exhaust air itself is reduced, so dew condensation can be effectively prevented.

[Brief explanation of drawings]

Fig. 1 is a vertical side view of a grain dryer, Fig. 2 is a longitudinal side view of a grain dryer used for carrying out the present invention, and Fig. 3 is a block circuit diagram of a control device for the hot air supply device. be. Explanation of drawing symbols, A...Grain dryer, a...Hot air supply device, P...Fuel pump, S1...Temperature sensor, S
2... Humidity sensor, 1... Aircraft, 10... Grain tank, 10a
...Machine wall, 10b...Insulating material, 11...Exhaust port, 2...Grain circulation system, 20...Rotating shutter, 21...Lower conveyor, 22...Elevator, 23...Upper conveyor, 3
...Air guide path, 30...Partition wall, 4...Burner device, 4a
...Motor that drives the burner fan, 4b...Motor that drives the fuel pump, 40...Temperature control circuit, 5...Blower, 5a...Rotary blade, 5b...Blower motor, 50...Blower speed control circuit, 51...Blower speed calculation circuit.

Claims (1)

[Scope of Claims] 1. A hot air supply device for a grain dryer comprising a burner device that generates hot air and a blower that sends the hot air generated by the burner device to the grains that are injected into the body of the machine. Hot air supply in a grain dryer, characterized in that the amount of air blown by the blower is controlled so that it increases as the humidity of the exhaust air discharged to the exhaust port side of the machine body increases and decreases as the temperature of the exhaust air decreases. How to control the device. 2. In the hot air supply device of a grain dryer, which consists of a burner device that generates hot air and a blower that sends the hot air generated by the burner device to the grains that are injected into the machine body, the rotation speed of the blower is controlled. A blower speed control circuit is installed to control the blower speed, and a humidity sensor installed on the exhaust side of the aircraft causes the rotation speed of the blower to increase as the humidity of the exhaust air increases, and as the temperature of the exhaust air decreases, the blower speed increases. 1. A control device for a hot air supply device in a grain dryer, characterized in that the rotation speed of the hot air supply device is controlled to decrease.