JPS62206374A - Method of controlling drying of circulation type cereal drier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drying control method for a circulating grain dryer that circulates grain between a storage section and a drying section and dries the grain with hot air in the drying section.

[Conventional technology]

Conventionally, the hot air temperature in the drying section was determined based on the type of grain, the amount of grain loaded into the dryer, the outside temperature, etc., and the hot air temperature was kept constant from the start of drying until the end of drying.

[Problem that the invention seeks to solve]

However, since the moisture content of grain is high in the early stage of drying,
As shown in Figure 4, there was a problem in that it took time for the grain temperature to rise and the drying time became longer.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a drying control method for a circulating grain dryer that can shorten drying time.

(Means for Solving the Problems) In the present invention, the grain is circulated between the storage section (10) and the drying section (12), and hot air is passed through the drying section (12) to set the target value Ta of the hot air temperature. Temperature TO and grain filling W
Calculate from and control the hot air temperature to the target value,
In the drying side i11 method of the circulating grain dryer for drying grain, the hot air temperature remains at the target 1 while the grain circulates between the storage section (10) and the drying section (12) after the start of drying.
It is characterized in that it is controlled to be equal to the value obtained by adding a predetermined value K to ii T a.

[Effect]

Therefore, the grain temperature rises quickly in the early stage of drying, and the drying time of the grain can be shortened.

Since the grain has a high moisture content in the early stages of drying, the quality of the grain will not deteriorate even if the hot air temperature is increased only during the first stage.

〔Example] The present invention will be explained in detail according to the drawings.

Figure 1 shows an example of an IFf grain dryer.
It has an upper storage section 10 and a lower drying section 12.

The drying section 12 is provided with a flow path 14 partitioned by a cane wall surface, through which the grains from the storage section 1o flow down. Hot air chambers 16 and exhaust air chambers 18 are alternately formed between adjacent flow passages 14. Hot air is sent to the hot air chamber 16 by a burner and a blower fan (not shown), and flows through the flow path 14 to the exhaust chamber 18 side. As a result, the grains in the flow path 14 are dried. A rotary valve 20 is provided at the lower opening of the flow path 14 to allow dried grains to fall into a lower hopper 22.

A screw conveyor 24 is provided at the bottom of the lower hopper 22 to supply grain to the lower part of a packet conveyor 26. This grain is on packet conveyor 2
6 to be lifted above the storage section 10 and dropped onto the rotary equalizer 28.
The grains in 128 fall into the storage section 10 under the influence of centrifugal force, and the upper surface of the deposited grains is shaped like a pot.

A temperature sensor 30 is disposed within the hot air chamber 16 to detect the hot air temperature T.

Further, a temperature sensor 32 is disposed outside the dryer body to detect the outside air temperature T0.

The detection signals of the temperature sensors 30 and 32 are sent to the multiplexer 34.
, microcomputer 38 via A/D converter 36
It is designed to be supplied to The amount W of grain loaded into the dryer is set by a loading amount setting device 40, and the setting signal is supplied to the microcomputer 38. The microcomputer 38 includes a temperature sensor 3G,
32. Generated heat is sent to the generated heat amount adjustment circuit 44 according to the input signal from the filling amount setting device 40! It supplies the regulation signal.

The generated heat amount adjustment circuit 44 is configured to adjust the flow rate of kerosene to a burner (not shown) and the amount of air mixed with this kerosene.

Next, the software configuration of the microcomputer 38 will be explained according to the flowchart shown in FIG.

In step 100, outside temperature To and grain loading 1w
Then, in step 102, the hot air temperature target value Ta is determined as follows.

Ta-aTo+bW+c... (1) K 4-fW
+g... (2) Ta←Ta10K
... (3) Here, K is the increment of the hot air temperature that is increased in the first cycle compared to the second and subsequent cycles, for example, 5°C can be adopted as shown in Fig. 3. , axc, f, and g are positive constants.

Then in step 104 the grain circulation speed V and -
Find the circulation as follows. The circulation speed (2) is the amount of grain dropped from the raw pulp pulp 20 per unit time, and the circulation time is the time it takes for the entire amount of grain to circulate through the storage section 10 and the drying section 12.

vth-1/(h-mW) ... (4) L-W/
V... (5) Here, h and m are positive constants.

Next, the process proceeds to step 106, where the hot air temperature T is read, and the process proceeds to step 108, where the amount of fuel and air supplied to the burner is controlled so that the temperature T1 becomes the target value Ta, thereby controlling the amount of heat generated. Then, in step 110, it is determined whether one cycle time t has elapsed, and the processes in steps 106 and 108 are repeated for -cycle time t.

If it is determined in step 110 that one circulation time t has elapsed, the process proceeds to step 111, where the target value Ta is reduced to a predetermined value (0).Then, the process proceeds to step 112, where the hot air temperature T
1 is read, and in step 114, the amount of heat generated by the burner is controlled so that the hot air temperature T1 becomes the target value Ta.

Next, if it is determined in step 116 that the drying is not completed, the processes in steps 112 and 114 are repeated.

The completion of drying is determined by automatically measuring the moisture content of the grain using a moisture meter, for example, and checking whether the moisture content reaches the set moisture content. If it is determined in step 116 that drying is complete, the process proceeds to step 118. The above process is completed by cutting off the kerosene supply to the burner.

In this way, the hot air temperature in the hot air chamber 16 and the average temperature of the grains become as shown in FIG. That is, in the first cycle, the hot air temperature is set higher by K, so that the average grain temperature rises faster than in the conventional example shown in FIG. During the first cycle, the moisture content of the grain is relatively high, so the average grain temperature does not become too high and the quality of the grain deteriorates.

Note that the value of the increment in hot air temperature (initial i1J) only needs to be a positive value, and does not need to depend on the grain loading WkW.

Alternatively, it may be a value that decreases over time. Formula (1)
, (4) are examples, and of course are not limited thereto.

〔Effect of the invention〕

In the drying control method for a circulating grain dryer according to the present invention, the target value Ta of the hot air temperature is calculated from the outside temperature TO and the grain loading amount W, and after the start of drying, the grains are transferred to the storage section (10) and the drying section ( 1
2) - While circulating, a predetermined value K is added to the target value Ta as the hot air temperature target value Ta, and the hot air temperature is controlled so that the hot air temperature becomes equal to the target value,
During this cycle, the moisture content of the grain is relatively high, so the temperature of the grain can be raised quickly without deteriorating the quality of the grain, which is an excellent feature that shortens drying time. have an effect.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a circulating grain dryer according to an embodiment of the present invention, Fig. 2 is a control flowchart, Fig. 3 is a diagram for explaining the operation of this embodiment, and Fig. 4 is an operation of a conventional example. It is a line diagram provided for explanation. 10...Storage section 12...Drying section 14...Flow path 16...Hot air chamber 18...Exhaust chamber 20...Lower valve 24...Screw conveyor 26...Packet conveyor 28 ...Rotary equalization 1128 30.32...Temperature sensor 40...Filling amount setting device

Claims (1)

[Claims] The grain is circulated between the storage section (10) and the drying section (12), and the hot air is passed through the drying section (12) to calculate the target value Ta of the hot air temperature from the outside temperature To and the amount of grain loaded. In a drying control method for a circulating grain dryer that controls the temperature to a target value and dries the grain, during the period during which the grain circulates between the storage section (10) and the drying section (12) after the start of drying, A drying control method for a circulating grain dryer, characterized in that the hot air temperature is controlled to be equal to a value obtained by adding a predetermined value K to the target value Ta.