JPH0623705B2 - Temperature compensation method of moisture meter for grain dryer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a temperature correction method for a moisture meter for grain drying equipment.

(Prior Art) Conventionally, in a circulation type grain drying apparatus, a grain of the grain being discharged from the drying chamber and being circulated and supplied to the storage chamber is sampled, the sample grain is crushed, and then the moisture content is measured by a moisture meter. It is known that the water content is measured, and the measured water content is corrected according to the temperature of the sample particles and then displayed to the operator.

The correction of the water content is performed because an error of about 10% occurs with respect to the grain temperature of 1 ° C. Therefore, in order to accurately measure the water content, it is necessary to measure the grain temperature after the sample grains are crushed by an electrode roll that is substantially equal to the outside air temperature and further cooled, but the grain of the crushed sample grains must be measured. Since it is extremely difficult to directly measure the temperature, conventionally, a temperature sensor for detecting the electrode temperature or the temperature near the electrode is provided in or near the electrode roll of the moisture meter, and the temperature measured by the temperature sensor is sampled. Considering the grain temperature T of the grain, the corrected water content was calculated and displayed by, for example, an arithmetic calculation of corrected water content = measured water content− (T−20 ° C.) / 10.

(Problems to be Solved by the Invention) However, since the known one regards the electrode temperature or the electrode vicinity temperature as the grain temperature T of the sample grain, when the temperature T of the grain discharged from the drying device becomes high, Since the grain is not cooled to the electrode temperature even after being crushed by the electrode roll,
A considerable difference occurs between the electrode temperature and the grain temperature T, and the accurate grain temperature T
However, there is a problem in that the accuracy of the moisture meter is deteriorated.

(Means for Solving the Problem) Then, a series of experiments were conducted to more accurately determine the grain temperature T of the sample grain from other relevant temperatures, and there was a correlation at some temperatures. There was found.

FIG. 2 shows the exhaust air temperature B exhausted from the drying chamber on the horizontal axis,
It is the graph figure which set the vertical axis to the grain temperature R conveyed in the elevator for grain circulation, and it is calculated | required that the exhaust air temperature B and the grain temperature R have a direct proportional relationship, and it collects as a sample grain. It was found that the grain temperature R to be obtained is determined by the exhaust air temperature B.

Therefore, as described above, when the sample particles are crushed by the electrode roll, a considerable amount of heat is taken by the electrode roll whose temperature is substantially the same as the outside air temperature, and the sample particles are cooled. However, it was found that the cooling rate is constant, is large when the grain temperature R is high, and is small when the grain temperature R is low, and the exhaust air temperature B and the electrode temperature C have a direct proportional relationship as described above. .

From the above, the grain temperature T after being crushed is the grain temperature R
And the electrode temperature C, the grain temperature R was found to be obtained from the exhaust air temperature B, and using the constant K (approximately 0.3) obtained by the experiment, the grain temperature T = {K × B + (1−K) × C} However, K = constant B = exhaust air temperature C = electrode temperature was calculated.

Therefore, according to the present invention, the grain temperature T of the sample grain is set to the exhaust air temperature B exhausted from the drying chamber and the electrode temperature or the electrode vicinity temperature C.
It was designed to be more accurately determined by
Sample particles are collected from the grains while being discharged from the storage chamber 18 and circulated in the storage chamber 18 and circulated.
The moisture content is measured by means of the moisture content, and the moisture content is corrected by the grain temperature T. The grain temperature T of the sample grain is not directly measured, but the exhaust air temperature B discharged from the drying chamber 7 and the moisture measuring device. Electrode temperature C of electrode roll 28 of 27 or its vicinity
And a temperature correction method of a moisture meter for a grain drying apparatus for obtaining the grain temperature T from the weighted algebraic sum of the exhaust air temperature B and the electrode temperature C.

(Example) An example of an apparatus capable of carrying out the method of the present invention will be described with reference to the drawings. 1 is a grain collecting section placed on a weighing scale 2, and has a pair of left and right inflow sections 3, 3. Rotary valves 4 and 4 are provided below the inflow portions 3 and 3, respectively, and the lower sides of the rotary valves 4 and 4 are surrounded by a trough 5, and a spiral conveyor 6 is horizontally provided on the center upper surface of the trough 5. Reference numeral 7 denotes a drying chamber placed on the upper part of the grain collecting unit 1, which forms a pair of left and right flow-down type drying chambers 9 and 9 in which the lower outlets 8 and 8 are fitted to the inflow units 3 and 3. The flow-down type drying chamber 9, 9
A hot air supply chamber 10 is formed between them, hot air exhaust chambers 11 and 11 are formed outside the downflow drying chambers 9 and, and an exhaust air temperature sensor b is provided in the hot air exhaust chamber 11. . 12 is a flow-down type drying room 9,
Porous plates on both sides of 9, a burner connected to the hot air supply chamber 10, a blower fan connected to the drying chamber 7, a fuel tank 15, a fuel pump 16, and a fuel valve 17.

Reference numeral 18 denotes a humidity control section installed at the upper part of the drying chamber 7, which has a large humidity control tank 19, and a pair of left and right funnels 20, 20 are formed at the lower part of the humidity control tank 19, and the funnels 20, 20 are provided. Bottom opening 2
The reference numerals 1 and 21 are fitted to the upper ends 22 and 22 of the flow-down type drying chambers 9 and 9, respectively.

23 is an elevator for lifting the grain discharged from the spiral conveyor 6, 24 is a discharge gutter for the grain, 25 is an upper conveyor, and the elevator 23 circulates and supplies the grain from the grain collecting unit 1 to the humidity control tank 19. A sample collecting unit 26 for collecting a part of the grains is provided. The sample collecting section 26 is composed of a spiral conveyor for collecting grains one by one, and a moisture measuring device 27 is provided on the discharge side thereof.
To provide. The water content measuring device 27 grinds the sample particles collected by the sample collecting section 26, and then measures the resistance voltage to obtain the water content. A pair of electrode rolls 28 having different peripheral speeds and a resistance voltage converter 29 are used. , A / D converter 30, central processing circuit
31 and a display unit 32. Then the electrode roll
28 is provided with a temperature sensor c for measuring the electrode temperature C of the electrode roll 28.

FIG. 1 shows the whole control circuit for measuring the water content of the present invention. The exhaust air temperature sensor b, the electrode temperature sensor c, and the moisture measuring device 27 are connected to the A / D converter 30. To do. 33 is a ram, 34 is a rom, 35 is an operation part, and 36 is a setting S.
W and 37 are safety sensors, 38 is an input port, 39 is an output port, and 40 is a transport motor of the elevator 23.

(Operation) Next, the operation will be described.

When grains are supplied one after another from the inlet at the lower end of the elevator 23, the grains will pass through the elevator 23 and the discharge gutter 24, and the upper conveyor.
From 25, the humidity control tank 19 and the downflow-type drying chamber 9 are filled, and here the burner 13 supplies the hot air through the hot air supply chamber 10.
After being dried by hot air of 50 ° C., it is fed out by the rotary valves 4 and 4 and discharged to the elevator 23 by the spiral conveyor 6, and is again circulated and supplied into the humidity control tank 19 by the elevator 23.

Then, the water content of the grains is obtained by collecting grains rising in the elevator 23 one by one by the sample collecting unit 26, crushing them, and measuring them with the water content measuring device 27. The grain temperature T of the sample grain thus obtained is the exhaust air temperature B obtained by the exhaust air temperature sensor b, the electrode temperature C obtained by the electrode temperature sensor c, and the constant K obtained by the experiment (approximately 0. It is obtained from 3).

That is, for example, a. Exhaust air temperature B is 33 ℃. Electrode temperature C is 20 ° C, d. When the constant K is 0.3, the grain temperature T is obtained by the above equation T = {K * B + (1-K) * C}. Substituting the above numerical values into these results in T = {0.3 × 33 + (1-0.3) × 20}, and the grain temperature T becomes 23.9 ° C.

Substituting this into the conventional formula corrected moisture content = measured moisture content− (T−20 ° C.) / 10, the corrected moisture content = measured moisture content− (23.9 ° C.−20 ° C.) / 10 is obtained. If the measured water content is 15%, for example, the value obtained by subtracting 0.39% from 15% is 14.61.
% Is displayed on the display unit 32.

(Effect) As described above, in the conventional circulation type grain drying device,
Samples of the grains discharged from the drying chamber and being circulated and supplied to the storage chamber are sampled, and the water content of the sample grains is measured with a moisture meter after crushing the sample grains, and the measured water content is the sample. It is publicly known that the correction is displayed according to the temperature of the grain and then displayed to the operator. Therefore, the correction of the water content is fixed in the measurement result depending on the grain temperature of the sample grain (grain temperature 1 ° C.
Error is about 10%). Therefore, in order to accurately measure the water content, it is necessary to measure the grain temperature after the sample grains are crushed by an electrode roll that is substantially equal to the outside air temperature and further cooled, but the grain of the crushed sample grains must be measured. Since it is extremely difficult to directly measure the temperature, conventionally, a temperature sensor for detecting the electrode temperature or the temperature near the electrode is provided in or near the electrode roll of the moisture meter, and the temperature measured by the temperature sensor is sampled. Considering the grain temperature T of the grain, the corrected water content was calculated and displayed by, for example, an arithmetic calculation of corrected water content = measured water content− (T−20 ° C.) / 10. However, since the known one regards the electrode temperature or the temperature near the electrode as the grain temperature T of the sample grain, when the temperature T of the grain discharged from the drying device becomes high, the grain is crushed by the electrode roll and then crushed. Since it is not cooled to the electrode temperature, there is a considerable difference between the electrode temperature and the grain temperature T, an accurate grain temperature T cannot be measured, and the accuracy of the moisture meter deteriorates.

However, according to the present invention, the storage chamber 18 discharged from the drying chamber 7 is
Sample grain is collected from the grain while being piled up and circulated in the
Smash this and measure the water content with a moisture measuring device 27,
When the moisture content is corrected by the grain temperature T, the grain temperature T of the sample grain is not directly measured, but the exhaust air temperature B discharged from the drying chamber 7 and the electrode roll of the moisture measuring device 27.
The temperature correction method of a moisture meter for grain dryers, which measures the electrode temperature C of 28 or its vicinity and obtains the grain temperature T from the weighted algebraic sum of the exhaust air temperature B and the electrode temperature C Therefore, the grain temperature T of the sample grain can be accurately determined from the exhaust air temperature B exhausted from the drying chamber and the electrode temperature or the electrode vicinity temperature C without directly determining the grain temperature R before crushing. There is an effect that can.

[Brief description of drawings]

FIG. 1 is an overall control block circuit diagram, FIG. 2 is a graph showing the relationship between exhaust air temperature B and grain temperature R, FIG. 3 is a vertical sectional view of a grain drying device, and FIG. 5 and 5 are perspective views of the moisture measuring device. Explanation of symbols 1 ... Grain collecting unit, 2 ... Weight scale, 3 ... Inflow unit, 4 ... Rotating valve, 5 ... Gutter, 6 ... Spiral conveyor, 7 ... Drying chamber, 8 ... Downward Exhaust port, 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 ... Bottom opening, 22 ... Top, 23 ... Elevator, 24 ... Discharge gutter, 25 ... Upper conveyor, 26 ... Sampling section, 27 ... Moisture measurement Device, 28 ...
… Electrode roll, 29 …… Resistance voltage converter, 30 …… A / D converter, 31 …… Central processing circuit, 32 …… Display unit, 33 …… Ram,
34 …… Rom, 35 …… Operating section, 36 …… Setting SW, 37 ……
Safety sensor, 38 …… input port, 39 …… output port, 40
…… Conveyor motor, B …… Exhaust air temperature, C …… Electrode temperature, R
... Temperature of sample grain before crushing, T ... Temperature of sample grain after crushing, b ... Exhaust air temperature sensor, c ... Electrode temperature sensor.

Claims (1)

[Claims] 1. A sample grain is collected from a grain discharged from a drying chamber 7 and piled up and circulated in a storage chamber 18, and the sample grain is crushed to measure a moisture content by a moisture measuring device 27. Is corrected by the grain temperature T, the grain temperature T of the sample grain is not directly measured, but the exhaust air temperature B discharged from the drying chamber 7 and the electrode roll 28 of the moisture measuring device 27 or an electrode in the vicinity thereof. A temperature correction method for a moisture meter for a grain drying device, which measures a temperature C and obtains the grain temperature T from a weighted algebraic sum of the exhaust air temperature B and the electrode temperature C.