JPH0867315A - Storage cabinet - Google Patents

Abstract

PURPOSE: To grasp the moisture distribution in a material in a storage cabinet so that the occurrence of a high temperature part can be detected by providing an oscillator for oscillating electric waves toward the material stored in the cabinet and a receiver for receiving the electric waves oscillated from the oscillator and passed through the material. CONSTITUTION: Electric waves are shot from an antenna 9A to a coal layer 3 to be received through the coal layer 3 by antennas 9B-9D. The electric waves, after the repetition of transmission, attenuation, dispersion and diffraction in the coal layer 3, are received by the antennas 9B-9D to be sent to a signal processing unit 12 and show the temperature rise in the coal layer 3. Thereafter, the temperature is measured at every fixed time and when the high temperature part 10 is generated in the coal layer 3, the moisture distribution is changed. Since there is a difference between the electric wave properties of water and coal, the change in the moisture distribution of the coal layer 3 appears as the change in the received electric waves of the antennas 9B-9D. Since the change in moisture in the coal layer 3 can be grasped from the above result by comparing the initial value with a value measured until the previous time, the occurrence of high temperature in the coal layer 3 can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage for coal silo, grain silo, pulp silo, etc., capable of reliably detecting the temperature rise in the cold storage.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional coal silo. 1 is the silo body. Reference numeral 2 is a coal carry-in device that carries coal into the upper part of the silo body 1, and the coal 3 carried into the silo body 1 is stored in the silo. Reference numeral 4 is a wall of the silo body 1. Reference numerals 5A, 5B and 5C are thermometers installed on the wall 4. Reference numeral 7 is a coal dispensing unit provided at the bottom of the silo body 1. Reference numeral 6 denotes a coal unloading conveyor that receives and unloads the coal from the coal unloading unit 7.

In this coal silo, when the storage period of the coal exceeds two to three months, the components of the coal in the silo body 1 may oxidize and generate heat to spontaneously ignite. In order to detect this temperature rise, in the conventional silo, the thermometers 5A, 5B and 5C are installed on the wall 4 as described above.

FIG. 4 shows a block diagram thereof. Thermometer 5
The signals measured by A, 5B, and 5C are collected in the signal processing device 12, and the temperature rise is captured. If a temperature rise is detected, the coal discharging unit 7 discharges the entire amount of coal in the silo main body 1 for cooling, and the cooled coal is again charged from the coal carry-in device 2.

[0005]

The coal bed in the silo is essentially a heat insulator because of the low thermal conductivity of the coal itself, and even lower thermal conductivity of the aggregates of particulates.

Therefore, the above-mentioned thermometers 5A, 5B, 5
In the conventional coal silo that detects the temperature rise by C,
Even if a high temperature occurs in a part of the coal in the silo, this temperature rise cannot be sufficiently caught on the wall surface, and the conventional device described above does not work effectively, and it is difficult to fulfill the role of disaster prevention. There is a problem to do.

The present invention intends to provide a storage that can solve the above problems.

[0008]

[Means for Solving the Problems] The storage of the present invention has the following means. (1) It is provided with a transmitter that emits an electric wave toward the material stored in the refrigerator, and a receiver that receives the electric wave emitted from the transmitter and passed through the material. (2) In the present invention according to (1) above, the transmission device is 5
Radio waves with a frequency of 00 KHz to 1 GHz are emitted. (3) In the present invention according to (1) above, the transmission device is 5
Radio waves with a frequency of 00 KHz to 100 MHz are emitted.

[0009]

The function (1) of the present invention has the following function. That is, the material stored in the storage usually contains water. For example, in the case of coal, water content of 10% is usually contained. When a high temperature is generated in a part of the material layer in the storage, moisture evaporates in the high temperature portion and drying progresses.
The vaporized water vapor is collected in the material layer above the high temperature portion.
Thus, when a high temperature portion is generated in the material in the storage, the distribution of water in the material changes. Since the radio wave characteristics (dielectric constant, conductivity, etc.) of the material and water are different, when the radio wave emitted from the transmitter toward the material is received by the receiver, the received radio wave shows the distribution of water content in the material layer. The changes that accompany changes will appear. In this way, by grasping the change in the reception radio wave of the receiving device in a storage state with a constant storage state, it is possible to capture the change in the moisture distribution in the material in the storage chamber, and thereby the high temperature in the same material layer. It is possible to detect the occurrence of parts.

The frequency of the radio wave used to detect the moisture distribution of materials such as coal, grain, pulp, etc. stored in the storage is the attenuation characteristic of the radio wave in the material, the size of the detected part, the antenna length, etc. Determined by The attenuation characteristic of the radio wave is expressed by the penetration depth d of the following equation 1.

[0011]

[Equation 1]

From the above equation 1, it can be seen that the higher the frequency of the radio wave, the greater the attenuation in the material layer such as coal. But,
If the frequency exceeds 1 GHz, the attenuation is large and it cannot be used in a normal storage. On the other hand, in the case where water is present together with materials such as coal and water or dry coal and normal coal containing water, the water content may differ due to the difference between the values of εγ and tanδ of the material and water or the material containing dry material and water. It is possible to detect the distribution, that is, the occurrence of the dry portion. Therefore, if the penetration depth is large compared to the length of the detected part, the attenuation is weak and the change cannot be detected, and the radio wave in the frequency range lower than 500 KHz has low resolution and is not suitable for practical use.

For the above reasons, in the present invention (2), radio waves having a frequency in the range of 500 KHz / 1 GHz are adopted. This allows the moisture distribution of the material to be captured.

Furthermore, the current measurement system can easily measure the attenuation of radio waves when the frequency of the radio waves is 100 MHz or less. Therefore, in the present invention (3), radio waves having a frequency in the range of 500 KHz to 100 MHz are adopted. This ensures that the moisture distribution of the material can be captured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. DESCRIPTION OF SYMBOLS 1 is a silo main body, 2 is a coal carrying-in device which carries in coal to the upper part of the silo main body 1, 3 is a coal layer stored in the silo main body 1, 4 is the outer wall of the silo main body 1, 7 is the bottom of the silo main body 1. The coal delivery unit 6 provided is a coal delivery conveyor that receives and delivers the coal from the coal delivery unit 7.

Reference numerals 8A, 8B, 8C and 8D denote concave structure portions provided on a part of the outer wall 4 so as to project from the outer wall,
Antennas 9A, 9B, 9C and 9D are provided inside. The concave structure portions 8A and 8B are provided on one side of the outer wall 4,
The concave structures 8C and 8D are arranged on the other side of the outer wall so as to face each other with the coal layer 3 in between, and the concave structures 8A and 8C are at the same height.
B and 8D are at the same height.

Coal silo main body 1 rather than the antenna 9A
Radio waves are emitted toward the inner coal layer, and the antenna 9B,
9C and 9D are designed to receive radio waves that have passed through the coal seam. The antennas 9A, 9B, 9C and 9D are shown in FIG.
As shown in, the signal line is connected to the signal processing device 12. As for the radio wave emitted from the antenna 9A, the change of the received radio wave (signal strength, phase difference and their frequency characteristic difference) is large due to the moisture distribution in the coal layer 3, and the radio wave of the current measurement system is Those having a frequency in the range of 500 KHz to 100 MHz that can easily measure the attenuation are used.

As shown in FIG. 2, the high temperature portion 10 is provided in the coal bed 3.
When occurs, water evaporates from the high temperature section 10. A portion 11 indicated by diagonal lines is a low temperature portion in contact with the upper portion of the high temperature portion 10, but the water evaporated from the high temperature portion 10 is
It is condensed and collected on the coal surface of the low temperature portion 11 having a lower temperature than 0. With the passage of time, the high temperature part 10 dries, and in the low temperature part 11 above the high temperature part 10, the water content increases so that the distribution of the water content changes.

In this embodiment, radio waves are emitted from the antenna 9A toward the coal layer 3, and the radio waves passing through the coal layer 3 are received by the antennas 9B, 9C and 9D. The radio waves are repeatedly propagated, attenuated, dispersed, and diffracted in the coal layer 3, and then the antennas 9B, 9
The signal is received by C and 9D, the signal is sent to the signal processing device 12, and the temperature rise in the coal seam 3 is captured.

First, when the coal bed is mechanically stabilized in the initial stage of storage, radio waves are emitted from the antenna 9A to
The signals are received by B, 9C, and 9D, and the data is recorded and saved in the signal processing device 12.

After that, the same measurement is performed at regular time intervals. When the high temperature part 10 is generated in the coal layer 3, the above-mentioned change in water distribution occurs. Since there is a difference in the radio wave characteristics between water and coal, the change in the water distribution in the coal layer 3 is caused by the change in the received radio waves in the antennas 9B, 9C, 9D that perform reception (signal strength, phase difference and their frequency characteristic differences). ) Appears as.

Moreover, in the present embodiment, the change of the received radio wave is large at 500 KH due to the change of the water distribution in the coal layer 3.
Since a radio wave having a frequency in the range of z to 100 MHz is used, it is possible to increase the change in the received radio wave due to the change in the moisture distribution in the coal layer 3.

By comparing the above regular measurement results with the initial value and the measured values up to the previous time, the state of water change in the coal seam 3 can be grasped. As a result, it is possible to detect the occurrence of a high temperature / drying section in the coal layer 3. After detection, it is possible to prevent spontaneous ignition of coal by implementing appropriate disaster prevention measures.

In the above embodiment, the antennas 9A, 9B,
Although four antennas 9C and 9D are used, the number of antennas is not limited to this, and one antenna may be used as long as simultaneous reception and transmission are performed. Also, if the number of antennas increases, the time and effort for signal processing increases, but it becomes possible to grasp small changes. Therefore, in the present invention, the number of antennas is increased or decreased according to the required accuracy.

In the above embodiment, coal was used as the stored material in the silo, but the present invention is not limited to this, and wheat, soybeans and other grains, pulp, hay and other powders stored in a storage container The present invention can be widely applied to granules.

Furthermore, the frequency of the radio wave used in the present invention is not limited to 500 KHz to 100 MHz,
As described in the "Operation" column, 500 KHz to 1 GHz
It is possible to use one having a frequency in the range of.

[0027]

According to the present invention, as described in claim 1,
The transmitting device which emits an electric wave toward the material housed in the refrigerator, and the receiving device which receives the electric wave emitted from the transmitting device and passed through the material, further comprising:
As described above, by using a radio wave having an appropriate frequency, it is possible to catch the moisture distribution of the material stored in the refrigerator and reliably detect the generation of the high temperature part.

[Brief description of drawings]

FIG. 1 is a schematic view showing a part of an embodiment of the present invention in a cutaway manner.

FIG. 2 is a block diagram of signals in the embodiment.

FIG. 3 is a schematic view showing a part of a conventional coal silo, broken away.

FIG. 4 is a block diagram showing signal processing in the conventional coal silo.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coal silo main body 2 Coal carry-in device 3 Coal layer 4 Outer wall of silo main body 5A to 5C Thermometer 6 Coal unloading conveyor 7 Coal discharging part 8A, 8B, 8C, 8D Recessed structure part 9A, 9B, 9C, 9D Antenna 10 Coal layer High temperature part generated inside 11 Low temperature part inside coal bed 12 Signal processing device

Front Page Continuation (72) Inventor Takasumi Ujihara 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Mitsubishi Heavy Industries, Ltd. Hiroshima Works (72) Inventor Katsuhiko Yamada 4-6-22 Kannon-shinmachi, Nishi-ku, Hiroshima City Mitsubishi Heavy Industries Shares Company Hiroshima Institute

Claims (3)

[Claims] 1. A storage characterized by comprising: a transmitter that emits an electric wave toward a material stored in the store; and a receiver that receives a radio wave emitted from the transmitter and passed through the material. 2. The transmitter is 500 KHz to 1 GHz.
The storehouse according to claim 1, which emits radio waves of the frequency. 3. The transmitter is 500 KHz to 100 M
The storage according to claim 1, which emits radio waves having a frequency of Hz.