JPH0439596B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a grain drying method in which grains are dried by being exposed to hot air while being circulated using a circulating grain dryer.

[Prior Art] As shown in FIG. 1, a circulating grain dryer A normally has a grain tank 1 in which grains to be dried are placed inside the upper half of a box-shaped body a. A rotary shutter 2 is installed at the bottom of the machine body a to control the discharge amount and discharge grains from the discharge port at the bottom of the grain tank 1, and a rotary shutter 2 is installed at the bottom of the machine body a, and the grains discharged by the rotary shutter 2 are transported to the machine body. An elevator 4 is installed with a lower conveyor 3 for discharging the grains to the outside of the machine body a, and lifts the grains discharged by the lower conveyor 3 on the outer surface side of the machine body a.
(bucket elevator) is installed in the upper part of the machine a, and an upper conveyor 5 is installed on the upper part of the machine a to feed the grains lifted by the elevator 4 into the upper part of the grain tank. The intermediate part of the grain tank 1 that occupies the bottom of the grain tank 1 has an air guide path 6 that sends dry air (hot air) across the bottom of the grain tank 1, and an air guide path 6 that blows out from the air guide path 6. It is equipped with an exhaust passage (not clearly shown in the drawing) that guides the exhaust air that crosses the bottom of the grain tank 1 serving as the drying part to the outside of the machine, and an exhaust duct 7 that communicates with the exhaust passage. a hot air generating device (burner device) 8 that generates the drying air at the entrance of the air guide path 6;
The exhaust duct 7 is provided with a blower 9.

When drying grains using this circulating grain dryer A, first, with the operation of the hot air generator 8 and the rotary shutter 2 stopped,
The grains are fed to the lower conveyor 3 from the loading port provided on the side of the bottom of the elevator 4, or the grains are fed from the loading port provided at the bottom of the elevator 4 to the lower conveyor 3, the elevator 4, and the upper portion. A predetermined amount of grain is loaded into the grain tank 1 by operating the conveyor 5, and then from this state, the rotary shutter 2 and grain feeding devices such as the lower conveyor 3, elevator 4, and upper conveyor 5 are operated to produce grain. While circulating the grains in tank 1,
Drying work is carried out by activating the hot air generator 8 and the blower 9 to blow hot air (drying air) onto the circulating grains, and by continuing to operate the circulating grain dryer A for a predetermined period of time. I try to do this.

[Problems to be Solved by the Invention] By the way, the means for drying grains using the circulating grain dryer A has a problem in that as the drying of the grains progresses over time during the drying operation. Normally, drying efficiency decreases, and the temperature of the hot air applied to circulating grains cannot be increased to avoid deterioration of the grains.
There is a problem that efficiency cannot be improved because the work takes a relatively long time before and after the scheduled time.

The present invention has been made to solve this problem, and the object is to provide a new drying method that can perform efficient drying using a circulating grain dryer without causing deterioration of grains. With the goal.

[Means for Solving the Problems] The present invention has been made based on knowledge obtained through various studies and experiments in order to achieve the above-mentioned objects.

That is, in the above-mentioned drying means, the drying efficiency gradually decreases as the grains dry as the drying process progresses because the grains become denser as the drying progresses. As the moisture content of grains decreases as the drying process progresses, the grain feeding device of the grain circulation system increases. When the grain feeding speed was increased to increase the number of circulations, the accumulation of grains in the area where the hot air blows through, which is the drying part, became sparse due to the increase in the grain feeding speed. The results showed that the ventilation resistance was reduced and the drying efficiency was improved, making it possible to increase the drying efficiency and at the same time suppressing the rise in grain temperature during the drying process. Suppression of the increase in grain temperature by increasing this circulation speed is the second
As is clear from the diagram of the experimental results shown in the figure, in the conventional drying method in which hot air is applied to the grains while circulating them at a substantially constant circulation rate, the increase in grain temperature does not cause a decrease in the quality of the grains. The grain temperature change curve was much lower than the ideal grain temperature change curve when grains were dried by setting the hot air temperature to the upper limit.

This means that when a circulating grain dryer dries grains by blowing hot air while circulating them, the circulation speed of the grains increases as the grains dry during the drying process. In this case, the temperature of the supplied hot air may be increased until the grain temperature reaches the ideal grain temperature curve in the conventional means.

Therefore, when drying was carried out by increasing the circulation speed of the grains as the grains dried, and by increasing the temperature of the hot air supplied to compensate for the resulting drop in grain temperature, we found that the ventilation resistance The reduction in drying efficiency and the increase in hot air temperature significantly increased the drying efficiency, resulting in the shortening of the drying process without causing quality deterioration of the grains. Therefore, in the present invention, the above-mentioned As a means to achieve this purpose, in a grain drying method that uses a circulating grain dryer to dry the grains by blowing hot air while circulating the grains, moisture content of the grains is reduced by the progress of drying of the grains during the drying process. As the grain circulation speed decreases, the grain circulation speed is increased, and the temperature of the hot air applied to the grains is increased to compensate for the drop in grain temperature caused by the increase in the grain circulation speed, thereby drying the grains. The present invention proposes a method for drying grain using a circulating grain dryer characterized by drying.

[Example] Next, an example will be described in detail with reference to the drawings. Note that the same reference numerals as in the previous means are used for constituent members having the same effect.

In Fig. 3, a is the fuselage, 1 is a grain tank installed in the fuselage a, and 2 is an outlet at the lower end of a drying section (not clearly shown in the drawing) formed at the bottom of the grain tank 1. 3 is a lower conveyor installed below the rotating shutter 2; 4 is an elevator installed on the outer surface of the machine body a; 5 is an upper conveyor; A rotating equalizer, 6 a hot air guide path, 7 an air exhaust duct communicating with the air exhaust path, 8 a hot air generation device consisting of a burner device provided at the entrance of the air guide path 6, 9 an exhaust duct 7 10 is a dust remover, and P is a fuel supply pump for the hot air generating device 8, respectively.

In addition, W is from the grain tank 1 to the rotary shutter 2→
Moisture value detection device M1 installed to sample grains from a circulation system path of grains circulating in the order of lower conveyor 3 → elevator 4 → upper conveyor 5 → grain tank 1 and detect the moisture value (moisture content). is the aforementioned blower 9
M2 is a motor that drives the lower conveyor 3, M3 is a motor that drives the bucket conveyor 4b in the grain lifting tower 4a of the elevator 4, the upper conveyor 5, and the equalizer 5a, M4 is the motor that drives the rotary shutter 2. M5 is a motor that drives the above-mentioned moisture value detection device W, M6 is a motor that drives the above-mentioned upper conveyor and the take-out gutter 4c installed in the upper discharge cylinder part of the grain lifting tower 4a of the elevator 4, and the above-mentioned upper conveyor. M7 is a motor that drives the dust remover 10; M8 is a motor that drives the burner fan of the hot air generator 8; M9 is a motor that drives the burner fan of the hot air generator 8;
1 shows a motor for driving the fuel supply pump P of the hot air generator 8, and these motors are controlled by a control circuit in a control box b provided at an appropriate location on the outer surface of the aircraft body a.

Further, S1 is an outside temperature sensor including a thermistor or the like installed on the outer surface of the aircraft body a to detect the outside temperature, and S2 is an outside temperature sensor that detects the temperature of the hot air generated by the hot air generation device 8 and sent to the air guide path 6. A hot air temperature sensor consisting of a thermistor etc. disposed in the air guide path 6, S
3 is installed in grain tank 1 to detect the temperature of grains in grain tank 1.
S4 is a thermistor installed in the air exhaust duct 7 (or air exhaust path) to detect the temperature of the hot air that has blown through the drying area of the grain tank 1. S5 is a grain amount sensor including a level switch installed on the inner wall of the grain tank 1 to detect the amount of grain loaded in the grain tank 1, and S6 is a moisture value. A moisture detection sensor consisting of a roll electrode or the like is installed in the moisture value detection device W so as to detect the moisture value of the grain sampled by the detection device W, and these are connected to the control circuit in the control box b. ing.

Fig. 4 is a front view of the control box b, where D1 is a dial for setting the grain temperature, and D2 is a dial for setting the grain temperature, and D2 is a dial for setting the grain temperature. A grain type setting dial is used to change the grain type so that drying can be performed under suitable conditions, and D3 is a finishing moisture setting dial that sets the finishing moisture value.

Next, FIG. 5 shows a block diagram of a control circuit for controlling the circulation speed provided in the control box b.

In the same figure, S6 is the above-mentioned moisture value detection device W.
The moisture detection sensor K1 is the moisture detection sensor S.
A grain moisture detection circuit converts the signal sent from the grain moisture detection circuit K1 into a grain moisture value (moisture content) signal, and K2 calculates the circulating amount of grain according to a predetermined pattern from the grain moisture value signal sent from the grain moisture detection circuit K1. A circulation amount setting calculation circuit incorporating a computer, K3 is the circulation amount setting calculation circuit K.
A circulation system motor speed control circuit that controls the rotational speed of the motor of the grain feeding device of the grain circulation system, such as the lower conveyor 3, elevator 4, upper conveyor 5, equalizer 5a, etc., according to the setting signal sent from 2, Mn is the above-mentioned The motors in the circulation system include a motor M2 that drives the lower conveyor 3, a motor M3 that drives the elevator 4, the upper conveyor 5, and the equalizer 5a, and a motor M4 that drives the rotary shutter 2.

Then, according to the grain moisture value detected by the moisture detection sensor S6 of the moisture value detection device W and the grain moisture detection circuit K1 during the drying operation,
The circulation rate setting calculation circuit K2 performs calculations according to a predetermined pattern to control the rotational speed of the motor Mn of the circulation system to be changed. As shown in the figure, the optimum circulation amount when the grain moisture content (%) is M
A pattern is created by finding the circulation speed Sv through experiments, and the pattern is followed.As the moisture content (%) of the grain decreases as the drying process progresses, the rate of increase in the circulation amount gradually increases. It is designed to do so.

Next, FIG. 7 shows a block diagram of a control circuit for hot air temperature control provided in the control box b.

In the figure, K4 is an outside temperature detection circuit that detects the outside temperature based on a signal sent from the outside temperature sensor S1, and K5 is a grain amount detection circuit that detects the amount of grain based on a signal sent from the grain amount sensor S5.
K6 is a grain type detection circuit that sets conditions suitable for the selected grain based on the signal of the selected grain type sent from the grain type setting dial D2, and K7 is the outside temperature detection circuit K4 and the grain amount detection circuit K.
K8 is a grain temperature setting calculation circuit that calculates the ideal grain temperature to be set at the normal circulation speed indicated by the symbol in FIG. Grain temperature detection circuit K that detects grain temperature based on a signal sent from temperature sensor S3 (or exhaust air temperature sensor S4)
9 is a comparison circuit that compares the temperature signal sent from the grain temperature detection circuit K8 with the temperature signal sent from the aforementioned grain temperature setting calculation circuit K7; A hot air temperature setting calculation circuit that calculates the hot air temperature to be set based on the signal; K11 is a hot air generator output control circuit that controls the output of the hot air generator system based on the hot air temperature signal calculated by the hot air temperature setting calculation circuit K10; B is a fuel supply pump P/burner fan motor M controlled by the control circuit K11.
8. Shows a hot air generator system consisting of the motor M1 of the blower 9, etc.

With these, the temperature signal detected by the outside temperature detection circuit K4 is set to G, the grain amount signal detected by the grain amount detection circuit K5 is set to G, and the grain type signal detected by the grain type detection circuit K6 is set to G. When D, the grain temperature t to be set is t=f(to・G/D)
The grain temperature t is calculated by the grain setting calculation circuit K7 according to the symbol pattern in FIG. Based on this, the output of the hot air generator system B is controlled so that the temperature of the hot air sent by the hot air generator 8 is increased so as to increase the grain temperature by an amount that compensates for the difference between the set grain temperature and the actual grain temperature. I try to force myself to do so.

[Effects of the Invention] As explained above, the method of drying grains using the circulating grain dryer according to the present invention is a drying method of drying grains by blowing hot air while circulating the grains using the circulating grain dryer. In this method, the circulation speed of the grain is increased as the moisture content of the grain decreases due to the progress of drying of the grain during the drying process, and the temperature of the hot air applied to the grain is adjusted to reduce the circulation speed of the grain. Since the grain temperature is raised to compensate for the drop in grain temperature caused by the increase in grain temperature and dry the grains, the circulation speed increases as the moisture content of the grains decreases as drying progresses. The sparser density reduces ventilation resistance and lowers grain temperature, making it possible to increase hot air temperature without deteriorating quality, significantly improving drying efficiency. This makes it possible to perform efficient drying with shortened working time.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a circulating grain dryer, Fig. 2 is an explanatory diagram of the method of the present invention, Fig. 3 is a longitudinal cross-sectional side view of a circulating grain dryer used for carrying out the present invention, and Fig. 4 is the same as above. A front view of the control box, Fig. 5 is a block circuit diagram of the same control device as above, Fig. 6 is an explanatory diagram of a pattern incorporated in the circulation rate setting calculation circuit, and Fig. 7 is a block circuit diagram of the control device of the hot air generator. be. Explanation of drawing symbols, A... Circulating grain dryer, a
...Aircraft, b...Control box, 1...
Grain tank, 2...Rotary shutter, 3...Lower conveyor, 4...Elevator, 4a...Grain lifting tower, 4b...Bucket conveyor, 4c...Takeout gutter, 4d...Switching shutter, 5...Upper part Conveyor, 5a... Equalizer, 6... Air guiding path, 7... Exhaust duct, 8... Hot air generator, 9... Air blower, 10... Dust remover, P
... Fuel supply pump, W ... Moisture value detection device, M
1, M2, M3, M4, M5, M6, M7, M
8, M9...Motor, Mn...Circulation system motor, D1, D2, D3...Dial, S1...Outside temperature sensor, S2...Hot air temperature sensor, S3...Grain temperature sensor, S4...Exhaust air Temperature sensor, S5...Grain amount sensor, S6...Moisture detection sensor, Sv...Circulation amount, K1...Grain moisture detection circuit, K2...Circulation amount setting calculation circuit, K3...Circulation system motor speed control circuit, K4...Outside temperature detection circuit, K5...Grain amount detection circuit, K6...Grain type detection circuit, K7...
...Grain temperature setting calculation circuit, K8...Grain temperature detection circuit, K
9... Comparison circuit, K10... Hot air temperature setting calculation circuit, K11... Hot air generator output control circuit.

Claims (1)

[Claims] 1 In a grain drying method in which the grain is dried by blowing hot air while circulating the grain using a circulating grain dryer, as the moisture content of the grain decreases as the grain continues to dry during the drying process, the grain A circulation type that is characterized by increasing the circulation speed of the grains and increasing the temperature of the hot air applied to the grains to compensate for the drop in grain temperature caused by the increased circulation speed of the grains, thereby drying the grains. A method of drying grain using a grain dryer.