JPH054590B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drying temperature control method for a grain drying device.

(Prior art) Conventionally, a hot air temperature sensor installed in a hot air supply chamber of a grain drying device detects the supplied hot air temperature, an exhaust air temperature sensor installed in the hot air exhaust chamber detects the exhaust air temperature, and the temperature of the supplied hot air is A "weighted average value" is calculated from the above-mentioned exhaust air temperature and the calculated value is regarded as the detected grain temperature of the grain discharged from the drying room, and the detected grain temperature and grain A method of controlling the firepower of a burner by comparing it with a drying set temperature is known.

Therefore, the method of calculating the detected grain temperature of the grain from the supply hot air temperature and exhaust air temperature as described above is as follows, when hot air temperature = A, exhaust air temperature = B, detected grain temperature = C, and weight constant = K. This was done by substituting the arithmetic formula C=K×A+(1-K)B.

Incidentally, in the conventionally known Japanese Patent Application Laid-open No. 187781/1987, grain temperature control values corresponding to the moisture content measured for the grain to be dried are stored in a memory in which control values for grain temperature according to the moisture content of the grain are stored in advance. A hot air control method in a grain dryer is described in which a temperature control value is selected and the amount of heat of the hot air is controlled so that the temperature of the grain becomes the selected control value.

In addition, in the conventionally known Japanese Patent Application Laid-Open No. 59-104071, while sequentially detecting the grain temperature and hourly drying loss rate of the grain to be dried, the detected grain temperature and the detected hourly drying loss rate are detected. In a product that is dried while keeping it below a predetermined value according to the moisture content, when the initial grain temperature or initial moisture of the grain to be dried is high and the hourly drying rate is high, the grain temperature is the predetermined value. It describes a grain drying method characterized in that when the drying cannot be controlled to the following, drying is completed while controlling both or one of a heating device and a blower device in order to keep only the hourly drying loss rate at a predetermined value. ing.

The grain temperature measurement method described in the above-mentioned publication is based on a method of directly measuring grain temperature using a thermocouple or the like.

(Problems to be Solved by the Invention) Both the hot air control method described in JP-A-58-187781 and the grain drying method described in JP-A-59-104071 are based on thermoelectric This method is based on a method of directly measuring grain temperature using an equalizer. In this method of directly measuring grain temperature,
No matter what method is used, it is not possible to accurately measure the temperature of flowing kernels. This is because when a tool (sensor) is inserted, a cavity is always created on the downstream side of the flow, and the contact is not complete. There are also straw particles caught in the tools (sensors).

Therefore, when performing accurate automatic control using a computer, it is better to use a method that does not rely on the above-mentioned method of directly measuring grain temperature, and the present invention also
It is based on an indirect method of calculating hot air and exhaust air.

However, when drying grains, especially grains for seeds, the higher the drying temperature, the lower the germination rate.
Furthermore, the higher the moisture content, the greater the influence of the drying temperature tends to be. According to experiments, the upper limit of unhulled rice is 45
℃, and the upper limit for beer barley is 40℃, but even at the same drying temperature, when the moisture content is high, the germination rate decreases, and when the moisture content is low, there is no decrease in the germination rate.

However, in the known method, the "weighting constant K" is always constant regardless of the moisture content, so it is good immediately after drying starts, but when the moisture content decreases as the drying process progresses, the computer control using the above formula According to the report, excessive temperature control sometimes resulted in inefficiency.

(Means for Solving the Problems) Therefore, the present invention sets the weighting constant K according to the high moisture content at the initial stage of drying, and when the moisture content decreases as drying progresses, the drying temperature is adjusted accordingly. A hot air temperature sensor installed in the hot air supply chamber of the grain dryer detects the hot air temperature A, and an exhaust air temperature sensor installed in the hot air exhaust chamber detects the exhaust air temperature B. A weight multiplier K is related to the hot air temperature A and the exhaust air temperature B to determine the detected grain temperature C of the grain from K×A+(1−K)B, and the detected grain temperature C is input into a computer. In this method, a grain moisture meter is installed at a desired position to measure the moisture content so that the weight K changes depending on the moisture content of the grain. The moisture value of the meter was also input into the computer as a method of controlling the drying temperature of the grain drying apparatus.

(Example) An example of an apparatus capable of carrying out the method of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a grain collection section placed on a weighing scale 2, which has a pair of left and right inflow sections 3, 3, Rotary valves 4, 4 are provided below the inflow portions 3, 3, respectively, the lower sides of which are surrounded by a receiving gutter 5, and a spiral conveyor 6 is installed horizontally on the central upper surface of the receiving gutter 5.

7 is a drying chamber placed above the grain collecting section 1;
A pair of left and right downstream drying chambers 9, 9 are formed in which the lower end discharge ports 8, 8 are fitted into the inflow portions 3, 3.

A hot air supply chamber 10 is provided between the downstream drying chambers 9, 9.
and hot air exhaust chambers 11, 11 are formed on the outside of the downstream drying chambers 9, 9.

A hot air temperature sensor a is provided in the hot air supply chamber 10, and an exhaust air temperature sensor b is provided in the hot air exhaust chamber 11.
will be established. The hot air temperature A measured by the hot air temperature sensor a and the exhaust air temperature B measured by the exhaust air temperature sensor b are substituted into the arithmetic formula K×A+(1−K)B=C, and the weighted average value ” is required,
The weighted average value is regarded as the detected grain temperature C when the grain is discharged from the down-flow drying chamber 9 and is measured.

Here, K is a weight constant, which is set variably depending on the type of grain for seeds, but the present invention particularly
It is also provided variably depending on the moisture content D of the grains being dried.

That is, as shown in FIG. 4, for example, beer wheat seeds and ordinary seed rice are different; beer wheat has a lower heat resistance temperature, so the weighting constant K is set higher overall, and the detected grain temperature C is By measuring it at a higher temperature, it is dried at a lower temperature, and on the other hand, rice seed is set to be dried at a slightly higher temperature than beer wheat seeds.

Further, the weighting constant K is set in stages according to changes in the moisture content D, and is set so that when the moisture content D decreases, drying is performed at a correspondingly high temperature.

12 are perforated plates on both sides of the downstream drying chambers 9, 1;
3 is a burner connected to the hot air supply chamber 10; 14;
1 is an exhaust fan connected to the drying chamber 7, 15 is a fuel tank, 16 is a fuel pump, 17 is a fuel valve, 1
8 is a humidity control unit installed in the upper part of the drying room 7, and has a large humidity control tank 19, and a pair of left and right funnels 20, 20 are formed at the bottom of the humidity control tank 19.
The lower end openings 21, 21 of the funnels 20, 20 fit into the upper ends 22, 22 of the downstream drying chambers 9, 9, respectively. A moisture meter d is installed in the funnel 20 to measure the moisture content D of the grains.

Reference numeral 25 indicates an elevator for lifting grains discharged from the spiral conveyor 6, 26 indicates a discharge gutter thereof, and 27 indicates an upper conveyor. At a desired position outside the elevator 25, there is an outside temperature sensor for measuring the outside air temperature around the outer periphery of the elevator 25. A sensor 28 is provided.

FIG. 3 shows a control circuit for measuring the moisture content of the present invention, in which the hot air temperature sensor a
The exhaust air temperature sensor b, the outside air temperature sensor 28, and the moisture meter d are connected to an A/D converter 29. 30 is a central processing unit, 31 is a ram, 32 is a ROM, 33 is an operating unit, 34 is an input port, 35 is a display unit, 36 and 37 are output ports, and 38 is a transport motor for the elevator 25.

(effect) Next, we will discuss the effect.

When beer barley is supplied from the loading port at the lower end of the elevator 25, the beer barley ascends the elevator 25 and moves on the upper conveyor 27 via the discharge gutter 26.
It falls into the humidity control tank 19 and fills the downstream drying chamber 9, receives hot air from the burner 13 from the hot air supply chamber 10, dries it, is delivered by the rotation of the rotary valves 4, and is collected on the lance conveyor 6. It flows into the elevator 25 and is circulated and dried.

Therefore, the conditions during the initial drying operation are determined by hot air temperature sensor a, exhaust air temperature sensor b, and moisture meter d as follows: hot air temperature A = 42°C, exhaust air temperature B = 20°C, beer barley moisture content D = 32%. When measured, the beer barley weight constant K
From Figure 4, when the moisture content D is 32%, it is "0.8"
Therefore, the detected grain temperature C is 0.8 x 42 + (1 - 0.8) x 20 = 37.6°C using the arithmetic formula K x A + (1 - K) B.

However, as mentioned above, the upper limit for beer barley is 40℃.
However, to be safe, if you enter the drying temperature setting into the computer as 38℃, it will be lower than 38℃.
At 37.6 degrees Celsius, the drying process will continue.

Assume that the drying process has progressed a little and hot air temperature sensor a, exhaust air temperature sensor b, and moisture meter d measure hot air temperature A = 44°C, exhaust air temperature B = 24°C, and beer wheat moisture content D = 28%. For example, in the case of conventional computer control, from the formula K x A + (1 - K) B, 0.8 x 44 + (1 - 0.8) x 24 = 40°C, and the drying set temperature input to the computer is 38°C. Conventionally, the computer would close the fuel valve 17 and turn off the burner 1.
However, in the present invention, from Fig. 4, the weight constant K of beer barley is as follows when the moisture content is 28%.
0.6, the detected grain temperature C is calculated as 0.6 x 44 + (1 - 0.6) x 24 = 36℃, which is 36℃, which is lower than 38℃, and the computer closes the fuel valve 17 to weaken the output of the burner 13. It is efficient because you can proceed with the drying work without doing anything like that.

(Effect) What was described in conventional public relations was published in JP-A-58
−The hot air control method described in Publication No. 187781, etc.
All methods, such as the grain drying method described in JP-A-59-104071, directly measure grain temperature. No matter what method is used to directly measure grain temperature, it is not possible to accurately measure the temperature of flowing grains. This is because when a tool (sensor) is inserted, a cavity is always created on the downstream side of the flow, and the contact is not complete. Also, straw debris may get caught in the tool (sensor).

Therefore, when performing accurate automatic control using a computer, it is better to use a method that does not rely on the above-mentioned method of directly measuring grain temperature, and the present invention also
It is based on an indirect method of calculating hot air and exhaust air.

Therefore, in the drying work of grains, especially the drying work of grain grains for seeds, especially the drying work of grains for seeds,
The higher the drying temperature, the lower the germination rate, and the higher the moisture content, the greater the influence of the drying temperature. According to experiments, the upper limit for unhulled rice is 45℃ and the upper limit for beer barley is 40℃, but even at the same drying temperature, when the moisture content is high, the germination rate decreases, and when the moisture content is low, the germination rate decreases. There is no decline.

However, in the known drying method, K×A+(1
- K) Since the computer control was based on the formula in B, it was efficient immediately after drying started, but as the drying process progressed and the moisture content decreased, the burner was unnecessarily controlled by the computer, making it inefficient. Ta.

However, in the present invention, the weighting constant K is determined according to the high moisture content at the early stage of drying, and when the moisture content decreases as the drying progresses, the drying temperature is set to correspond to that amount, thereby increasing efficiency. The hot air temperature A is detected by the hot air temperature sensor installed in the hot air supply chamber of the grain drying equipment, the exhaust air temperature B is detected by the exhaust air temperature sensor installed in the hot air exhaust chamber, and the hot air temperature A and the exhaust air temperature are The detected grain temperature C of the grain is determined from K×A+(1-K)B, which relates the weight multiplier K to the wind temperature B, and the detected grain temperature C is input into a computer and compared with the grain drying set temperature. In this method, a grain moisture meter is installed at a desired position and the moisture value of the moisture meter is also input into the computer so that the weight multiplier K changes depending on the moisture content of the grain. Since this is a drying temperature control method for grain drying equipment, as mentioned above, in the case of the conventional method,
Since the weight multiplier K was not changed, the burner was automatically adjusted weakly, which was inefficient, but under similar conditions,
In the present invention, since the weight multiplier K changes, the burner 13
It continues strongly as it is, and has the effect of always being able to carry out the highest efficiency drying.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the grain drying apparatus, FIG. 2 is a side view thereof, FIG. 3 is a block circuit diagram, and FIG. 4 is a graph showing the relationship between weighting constants and moisture content. Explanation of symbols, 1...Grain collecting section, 2...Weighing scale, 3
...Inflow section, 4... Rotary valve, 5... Receiving gutter, 6...
Spiral conveyor, 7...Drying chamber, 8...Lower end outlet, 9...Downflow drying chamber, 10...Hot air supply chamber,
11... Hot air exhaust chamber, 12... Perforated plate, 13...
Burner, 14...Exhaust fan, 15...Fuel tank, 16...Fuel pump, 17...Fuel valve,
18...Humidity control section, 19...Humidity control tank, 20...
Funnel, 21... Lower end opening, 22... Upper end, 24
... Grain temperature sensor, 25 ... Elevator, 26 ...
Discharge gutter, 27... Upper conveyor, 28... Outside temperature sensor, 29... A/D converter, 30... Central processing section, 31... Ram, 32... ROM, 33...
Operation unit, 34...input port, 35...display unit,
36, 37... Output port, 38... Conveyance motor, a... Hot air temperature sensor, b... Exhaust air temperature sensor, d... Moisture meter, A... Hot air temperature, B... Exhaust air temperature, C... ...detected grain temperature, T...drying set temperature.

Claims (1)

[Scope of Claims] 1. A hot air temperature A is detected by a hot air temperature sensor provided in a hot air supply chamber of a grain drying device, an exhaust air temperature B is detected by an exhaust air temperature sensor provided in a hot air exhaust chamber, and the hot air temperature is The detected grain temperature C of the grain is determined from K×A+(1-K)B, which relates the weight multiplier K to the temperature A and the exhaust air temperature B, and the detected grain temperature C is input into a computer to set the grain drying temperature. In this method, a grain moisture meter is installed at a desired position and the moisture value of the moisture meter is also measured so that the weight K changes depending on the moisture content of the grain. A method for controlling a drying temperature of a grain drying apparatus by inputting information into the computer.