JPH01196483A - Sample drier - Google Patents

Abstract

PURPOSE:To permit the drying of the whole of sample so as to achieve an objective moisture value correctly, by providing a control unit, finishing the drying operation of the sample, which is effected by a microwave generating device, when a metering value in a metering unit has arrived at an operated sample weight. CONSTITUTION:Grain 7 is thrown into a sample vessel 6 while the vessel 6, into which the sample to be dried is thrown, is loaded on the putting table 9 of a metering unit 8. In this case, the sample vessel 6 and the putting table 9 are arranged in a sealed case 10. A microwave generating device 12 is arranged in the sealed case 10 and a high-frequency signal 11 is projected against the grain 7. The sample is dried from the inside thereof by microwave in such a manner, the sample weight during drying is measured in the metering unit and a phenomenon that the metered value has become an operated weight in accordance with an objective moisture value is detected by a control unit 13 then, the drying operation of the sample, which is effected by the microwave generating device, may be finished.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sample drying device used when preparing samples for testing by drying sampled grains to a target moisture value.

BACKGROUND OF THE INVENTION Conventionally, this type of sample drying apparatus has been constructed as shown in FIG. Sample 1 to be dried is placed in sample container 2, and hot air is generated I! The hot air 4 generated in step 13 passes between the samples 1 placed in the sample container 2,
It is configured to dehydrate sample 1. A capacitive moisture sensor 5 is inserted into the sample 1 placed in the sample container 2, and when the detected moisture value of the moisture sensor 5 reaches the target moisture value, the drying operation using the thermal HA 4 is terminated. do.

Problems to be Solved by the Invention In such a conventional configuration, the upper layer H is difficult to dry because it is dried by ventilation of hot air.
Since the end of drying is detected by the moisture sensor 5 inserted into the sample, an error occurs depending on the measurement accuracy of the moisture sensor 5.Although grains near the moisture sensor 5 can be set to the target moisture value, in particular, sample 1 When the initial moisture value of H is very high or when the degree of contamination with dust is high, variations in the degree of dryness occur between the lower layer and the upper layer H. Therefore, even if the dried sample 1 is taken out of the sample container 2, sealed in a single bag, and left for a predetermined period of time to allow the moisture content to average inside the bag, the averaged moisture value will be It is difficult to reach the target moisture level.

An object of the present invention is to provide a sample drying device that can accurately bring the entire sample to a target moisture content.

Means for Solving the Problems The sample drying device of the present invention includes a microwave generator for drying, a weighing section that measures the weight of the sample being dried,
Calculate the sample weight at the end of drying from the moisture value of the sample before drying, the weight of the sample before drying, and the target moisture value, and when the weight value of the weighing section reaches the calculated sample weight. and a control section for terminating the sample drying operation by the microwave generator.

Effect: According to this configuration, the sample is dried from the inside using microwaves, the weight of the sample during drying is measured by the weighing section, and the control section indicates that the weighed value has reached the calculated weight according to the target moisture value. Upon detection, the sample drying operation by the microwave generator is completed.

Example An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows the sample drying apparatus of the present invention. If the amount of sampled grain is 11f, then, for example, 980 g of grain 7 is put into the sample container 6, and the sample container 6 into which the sample to be dried is put is: A load is placed on the platform 9 of the weighing section 8. Here, a sample container 6 and a stage 9 are arranged inside a shield case 10. In addition, a microwave generator 12 that generates a high frequency signal 11 of the microwave frequency used in a household microwave oven is arranged inside the shield case 10. 7 is irradiated.

The remaining 20. of the grains sampled. is used to determine the initial moisture value of 980 g of grain placed in the sample container 6. In other words, 20. After the moisture has been completely removed from the grain, its weight W (g) is measured, and the moisture value (initial moisture value) M before the start of drying is determined by 20'-W 20'''M0...■.

is determined, and let MQ be the initial moisture value of the sample of 98Of.

When the sample in the sample container 6 is irradiated with the high frequency signal 11, the sample is uniformly heated from inside due to the characteristics of the microwave, and water evaporates.

Here, if the target moisture value of the dry finish is Mll, and the occasional net weight value by the weighing section 8 is W, the control section 13 calculates the following: 980-(M.-tap x 980°°°°°■) Instructs the microwave generator 12 to end the drying operation when the second equation is satisfied.

With this configuration, the entire sample inside the sample container 6 is heated almost uniformly by the high-frequency signal 11, and the control unit can detect that the weight value of the weighing unit 8 has reached the calculated weight according to the target moisture value. , 13 and ends the drying operation, measurement errors that occur when the moisture sensor 5 is used do not occur.

Note that even if the drying state is uneven inside the sample container 6, the dried samples are taken out from the sample container 6, sealed in one bag, and left for a predetermined period of time to cause the moisture content to average out inside the bag. By doing so, the averaged moisture value can be accurately set to the target moisture value.

Effects of the Invention As described above, according to the present invention, since drying is performed using microwaves, a uniform heating state can be obtained. Moreover, the completion of drying is determined by measuring the weight of the sample being dried in the weighing section, detecting by the control section that the measured weight has reached the calculated weight according to the target moisture value, and then starting the drying operation of the sample. Compared to conventional equipment, which determines when to finish drying by measuring the moisture value from time to time with a moisture sensor, it is possible to accurately bring the moisture value of the entire sample closer to the target moisture value, resulting in a good result. It is possible to make samples for testing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the sample drying apparatus of the present invention, and FIG. 2 is a block diagram of a conventional sample drying apparatus. 7... Grain [sample being dried], 8... Weighing section,
12...Microwave generator, 13...Control unit, M
Q...Initial moisture value [moisture value of the sample before drying starts]
, WO...Sample weight before drying starts, Mll...
Target moisture value, Wl...Weight value of the weighing section. Agent Yoshihiro Morimoto Figure 1 Figure 2

Claims (1)

[Claims] 1. A microwave generator for drying, a weighing unit that measures the weight of the sample during drying, and calculates the moisture value at the end of drying from the moisture value of the sample before drying, the weight of the sample before drying, and the target moisture value. A sample drying device comprising: a control unit that calculates a sample weight and causes the microwave generator to terminate a sample drying operation when the weight value of the weighing unit reaches the calculated sample weight.