JPH03225192A - Grain drying - Google Patents

Abstract

PURPOSE:To obtain drying products of high quality without spoiling germination rate and germinating energy while preventing the generation of cracking by a method wherein drying is effected by sending drying air having a normal temperature or about 40 deg.C upon the initial period of drying and, thereafter, the drying is effected while changing a preset drying air temperature, the amount of ventilation and a circulating speed in accordance with the moisture of grains. CONSTITUTION:The low-temperature drying of grains, charged into a dryer, is effected by pouring drying air, whose temperature is regulated so as to be a normal temperature or about 40 deg.C by the detecting operation of a drying air temperature detector 3 and the control operation of a grain temperature, reducing rate by drying and drying air temperature reference setting circuit 4. When the moisture of grains has become lower than 35%, for example, in such a manner, the numerical values of detecting grain temperature and detecting rate of reducing by drying of the grain temperature detector 1 and the rate of reducing by drying detector 2 as well as the reference numerical values of a grain temperature and a reducing rate of grain by drying are compared in a comparing circuit 5. Then, a signal is transmitted to a control circuit 6 so that the grain temperature becomes 35 deg.C or lower and the reduction rate by drying per hour becomes 1% or less when the moisture is 35%-30% or the grain temperature becomes 45 deg.C or lower and the reduction rate of drying per hour becomes 1.4% or less when the moisture is 20-13%, for example. The control circuit 6 controls a heating device 7, a ventilating device 8 and a circulating speed changing device 9 based on the signal to control the drying air temperature, the amount of ventilation and the circulating speed and continue drying operation.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method that does not impair germination properties even in grains with high moisture content and large variations in moisture content between grains. To develop a grain drying method that can dry grain to a predetermined moisture level while reducing moisture content.

[Prior art] Conventionally, the grain temperature and drying rate of the grain to be dried are sequentially detected over time from the early stage of drying, and the detected grain temperature and drying rate are adapted to the moisture content of the I9 material. By controlling the heating device or blower device so that the drying temperature is below a preset value, drying can be completed efficiently and with the highest possible efficiency without sacrificing quality. Prior to the filing of this application, a grain drying method that can be carried out to prevent shell cracking and quality deterioration due to abnormally high speed drying and abnormally high grain temperatures, and to produce dried grains with good taste without shell cracks, was disclosed. For example, it is described in Japanese Patent Publication No. 59-147c19 and is well known.

[Problems to be Solved by the Invention] By the way, in the conventional grain drying method of this kind, the grain temperature and drying rate of the grain are adjusted from the early stage of drying, regardless of the initial moisture content of the grain and the moisture content between grains. By controlling and drying the grain so that it satisfies predetermined conditions, it is possible to efficiently obtain high-quality dried grains by preventing the occurrence of shell cracking and deterioration of taste.

However, in general, in the early stages of grain drying, the moisture content of the germ is often high in proportion to the average moisture content of the whole grain, and when high-temperature hot air is applied to the germ with high moisture content, the germination rate and germination had the problem that it was significantly damaged.

The present invention aims to efficiently obtain a high-quality dried product with good taste without impairing the germination rate or vigor of grains with high moisture content and large variations in moisture content, while preventing the occurrence of shell cracking. The purpose is to provide a method for drying grains.

[Means for solving the problem] As mentioned above, when the germ of a grain has high moisture content, exposing it to high-temperature hot air will significantly impair germination. By exposing the germ part to low-temperature air, it dries quickly without impairing its germination ability, and after its moisture content has been reduced, the germ part dries out by exposing it to relatively high-temperature air without impairing its germination ability. It has the property of being possible.

Therefore, in the grain drying method of the present invention, high-moisture grain is dried by drying hot air while being circulated, and at the beginning of drying, drying air at room temperature to around 40°C is sent for at least one circulation. By drying, and then finishing the drying while changing the preset drying air temperature, air flow rate, and circulation speed according to the moisture content of the grain, the germination rate and germination force are not affected, and grain cracking does not occur. By preventing this, a high-quality dried product with good taste and efficiency can be obtained.

[Effects] Currently, grains with large variations in moisture content between grains and with an initial moisture content of 35% or more (e.g. beer barley,
wheat, seed rice) without reducing the germination rate or germination vigor.
2.5%, seed rice 15%), first of all, the grain loaded in the dryer should be circulated twice, for example, by the operation of the drying air temperature sensor and the grain temperature. ,
Under the control operation of the drying loss rate and drying air temperature standard setting circuit, drying air is applied to the grains to perform low-temperature drying so that the drying air temperature is from room temperature to around 40°C.

Then, the grains are dried by low-temperature drying air, and at the same time, the variation in moisture between grains is reduced.
The moisture content of the germ also decreases.

As described above, the preset number of circulation is completed,
When the moisture content is, for example, 35% or less, the detected grain temperature value and the detected drying rate value are sent as signals to the comparison circuit every hour, for example, by the operation of the grain temperature detector and the drying rate detector. At the same time, the grain temperature, drying rate, and drying air temperature standard setting circuit adapts to the moisture content of the grain over time, and the grain temperature standard value and drying rate standard value shown in Figure 2 are simultaneously output as signals. The signals are then sent to the comparison circuit, where they are compared. As a result, the grain has a moisture content of, for example, 35% to 30%, as detected by the grain temperature detector and the drying rate detector over time.
In this case, the grain temperature should be kept below 35℃, the drying rate should be kept below 1% per hour, and the moisture content should be kept at 35℃.
At 0-20%, the grain temperature is below 40℃ and the drying rate is 1.2% per hour.
Below, a signal is sent to the control circuit to keep the grain temperature below 45°C and the drying rate below 41.496 when the moisture content is 20% to 13%, and based on this control circuit, the heating device and the blower are installed. and the circulation speed converter are automatically controlled, and the drying air temperature, air flow rate, and circulation speed are controlled singly or at the same time by IFJ, and the drying operation is continued until the moisture content reaches a predetermined value. It is something.

By the way, during the above-mentioned drying process, the grain temperature and drying rate values may be larger than the grain temperature and drying rate standards due to the influence of outside air temperature, etc. When detected, the comparison circuit immediately operates to send a signal to the control circuit so that the grain temperature and drying rate values are below the preset grain temperature and drying rate reference values. Drying is carried out by controlling the amount of fuel supplied to the warming device or the amount of air blown by the blower and the circulation speed to maintain the grain temperature and drying rate at or below a preset value in accordance with moisture content. It is.

In addition to the above method, a method of cooling the grain by sending outside air or the like into the grain in the storage tank may also be used to control grain temperature and drying rate.

Due to the above-mentioned Luno effect, the grain to be dried is dried with ideal values for grain temperature and drying rate during the period from low temperature drying in the early stage of drying to finished moisture, so it is possible to dry the grain under abnormally high temperature conditions. The germination rate, germination vigor, and shell cracking caused by
Alternatively, not only can deterioration of quality such as taste be prevented, but also the efficiency of drying work can be improved.

[Example] A block circuit for implementing the grain drying method according to the present invention will be described.

In Figure 1, 1 shows the grain temperature of the grain to be dried over time until the end of drying, after drying the grain in the dryer at a low temperature with drying air at room temperature to around 40°C in the early stage of drying to lower the moisture content of the germ. The grain temperature detector l according to the present invention detects the grain temperature of the grain to be dried and sends the detection signal to the comparison circuit 5, for example, every hour. It has become so. 2 detects over time the drying loss rate, that is, the drying speed, of the grain to be dried after drying the grain at a low temperature with drying air at room temperature to around 40° C. in the early stage of drying, and sends the detected signal to the comparison circuit 5. The drying loss rate detector 2 according to the present invention detects the drying loss rate of the grain to be dried, that is, the drying rate, for example every hour. Reference numeral 3 denotes a drying air temperature detector for detecting the temperature of the drying air applied to the grains in the dryer in the early stage of drying and sending the detection signal to the comparison circuit 5. 4 is a reference setting for grain temperature, drying loss rate, and drying air temperature, and this circuit 4 performs low-temperature drying by exposing the grain in the dryer to drying air at room temperature or around 40°C in the early stage of drying. Based on the drying air temperature standard value for drying, and the moisture content of the grain when the grain temperature and drying rate of the grain to be dried are detected over time after the above-mentioned low-temperature drying is performed to lower the moisture content of the germ part. It has the function of sending signals of a grain temperature reference value and a drying rate reference value, which are set in advance, to the comparison circuit 5, respectively.

Therefore, in the grain temperature, drying loss rate, and drying air temperature standard setting circuit, as shown in FIG. Drying air temperature standard table for drying grains at low temperature with drying air at room temperature to around 40°C to a moisture content of 35%.
5% or less, the drying rate is 1% or less per hour, and the grain temperature is 40°C or less when the moisture content is 30% to 20%, the drying rate is 1.2% or less per hour, and the moisture content is 20%. ~13
The grain temperature standard table and the drying rate standard table are respectively set to maintain the grain temperature at 45° C. or lower and the drying rate to be 1.4% or lower.

5 receives signals sent from the grain temperature detector 1, drying rate detector 2, and drying air temperature detector 3, respectively, and signals sent from the grain temperature, drying rate, and drying air temperature reference setting circuit 4. This is a comparison circuit for comparing the received signal and sending the signal to the heating device 7, the blower device 8, and the circulation speed converting device 90 control circuit 6. The values of the drying air temperature detected by the drying air temperature, or the values of the grain temperature and drying rate detected by the grain temperature detector 1 and the drying rate detector 2, respectively, are shown in the grain temperature reference table and drying rate shown in Figure 2. When the values are higher than those determined in the reference table and the drying air temperature reference table, a signal is immediately sent to the control circuit 6 to control the amount of fuel supplied to the heating device 7, the amount of air blown by the blower device 8, and the dryer. The grain circulation speed converter 9 is controlled to finish drying while controlling the drying air temperature, grain temperature, and drying loss rate at the initial stage of drying so that they do not exceed set values.

In this way, it is possible to efficiently produce dried grains that have a high germination rate and vigor, are free from shell cracking, and have good taste.

For reference, the effect of drying air temperature on the germination rate (wheat) and germination vigor (beer barley) when the grain moisture content is the same but the germ moisture content is different is determined from the experimental results. This means that the higher the moisture content of the germ, the lower the germination rate and vigor caused by high-temperature air. Conversely, if the seeds are dried at a low temperature, the decline in germination ability can be prevented. On the other hand, since the drying rate of the germ is extremely high, it can be understood that it is effective to quickly reduce the moisture content even at low temperatures, and then efficiently dry the germ at a high temperature.

[Effects of the Invention] Since the present invention is a method as explained above, it produces the effects as described below.

In devices that dry hot air while circulating high-moisture grains, in the early stage of drying, the air temperature for at least one circulation of the grains is adjusted to between room temperature and 40%.
Drying is carried out by keeping the temperature around 0℃, and after that, the drying hot air temperature, air flow rate, and circulation speed are controlled individually or together in the morning to maintain the drying speed and grain temperature below the preset drying speed and grain temperature depending on the moisture content of the grain. However, since drying has been completed, even if the grain has a high moisture content and there are large variations in moisture between grains, drying at a low temperature in the early stage can eliminate moisture variations and reduce the moisture in the germ. ,
From then on, throughout the period until the end of drying, the grain temperature and drying rate are always controlled to be below the predetermined values, so that the germination rate and germination vigor are not impaired, and flavor deterioration due to abnormally high temperatures and high speed drying is avoided. It is possible to prevent shell cracking and efficiently produce high quality dried grains.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram for carrying out the method according to the present invention, and FIG. 2 is an example of a reference table of preset grain temperature, drying loss rate, and drying air temperature at the initial stage of drying. )... Grain temperature detector, 2... Drying rate detector, 3...
Drying air temperature detector, 4... Grain temperature, drying loss rate and drying air temperature reference setting circuit, 5... Comparison circuit, 6...
・Control circuit, 7... Warming device, 8... Air blower, 9
...Circulation speed converter

Claims (1)

[Claims] In systems that dry hot air while circulating high-moisture grains, the temperature of the drying air is maintained at room temperature to around 40°C at the beginning of drying, regardless of the moisture content of the grains, and after that, the grains are dried. A grain drying method in which drying is completed while changing the drying air temperature, air flow rate, and circulation speed so as to maintain the grain temperature and drying speed below preset grain temperatures and drying speeds according to moisture content.