JPH05340871A - Instrument for measuring water content of granular body - Google Patents

Abstract

PURPOSE:To obtain a highly accurate instrument for measuring water contents of granular bodies. CONSTITUTION:The title instrument is constituted of a belt-conveyor which transports a granular body 4, such as ores or coal, moisture meter 7 which is installed on the conveyor 1 and measures the water content of the granular body 4, granular body pushing aside device 6 which is installed on the upstream side of the meter 7 and pushes aside the surface of the body 4, weighting instrument 11 which measures the transported quantity of the body 4, computing element 16 which compares the measured value of the transported quantity with a preset transported value, and belt-conveyor speed adjusting device 18 which controls the speed of the conveyor 1 based on the calculated results of the element 16. Therefore, the measuring distance from the meter 7 to the body 4 can be always maintained constantly and the water content of the body 4 can be measured with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture measuring device for powder or granular material.

[0002]

2. Description of the Related Art Conventionally, a non-contact type infrared moisture meter is often used to measure moisture contained in powder or granular materials such as ores and coal transported by a belt conveyor. However, in the case of this infrared moisture meter, it is possible to measure only the moisture of the surface portion of the transported granular material, so that moisture evaporates from the surface of the granular material and dries, or the surface shape changes. There is a drawback that the measured value is likely to have an error due to a change with time.

By the way, as one of means for eliminating such a defect, as disclosed in, for example, Japanese Utility Model Publication No. 60-35879, the surface of the granular material is located upstream of the moisture measuring point of the granular material. There is proposed a technique of installing a powder and granular material separating device for separating the particles. That is, to briefly explain this powder and granular material sorting apparatus, as shown in FIG. 4, when the endless belt conveyor 1 travels on the pulley 2 by the rotation of the motor 3 to transport the powder and granular materials 4, Along the way, the surface of the granular material 4 is scraped off and exposed by the granular material separating device 6 attached to the central portion of the belt conveyor 1 by the gantry 5, and the layer thickness of the granular material 4 is made constant. Then, the water content on the exposed surface of the powdery or granular material 4 is measured by the water content meter 7 attached on the downstream side of the powdery or granular material separating device 6, and is displayed on the display 8. According to this, it is possible to accurately measure the amount of water contained in the granular material.

[0004]

However, in the case of using the powder / grain sorting device 6 of Japanese Utility Model Publication No. Sho 60-35879 as described above, adjustment of the height level in the vertical direction on the belt conveyor 1 is performed by the pedestal. Although it is possible by adjusting the height of No. 5, it cannot be easily adjusted during the operation of the belt conveyor 1, and the initial height level set at the start of the operation must be maintained. And the following problems occur. When the transportation amount is large, the level of the powder and granules 4 on the belt conveyor 1 becomes high, so that the scraping load of the powder and granule separating device becomes large and the device is damaged, or the powder and granules are transferred to the belt conveyor. Problems such as falling down occur. On the contrary, when the transport amount is small, the powder / grain sorting device 6
Since the granular material 4 does not come into contact with the above, the function of the device cannot be exerted. In addition, since the surface of the granular material 4 is not flat, the distance between the surface of the granular material and the moisture meter 7 fluctuates and the measurement error increases.

The present invention has been made in order to solve the above problems of the prior art, and an object of the present invention is to provide a moisture measuring device having high measurement accuracy.

[0006]

The present invention is directed to a belt conveyor for transporting particles such as ores and coal, and a moisture measuring device installed on the belt conveyor for measuring the water content in the particles. , The powder particle sorting device installed on the upstream side of this moisture measuring device to scrape the surface of the powder and granular material, the weighing device for measuring the transport amount of the granular material, and the transport amount detected by this weighing device It is characterized by comprising a calculator for comparing and calculating the measured value and a preset transport amount set value, and a belt conveyor speed adjusting device for controlling the speed of the belt conveyor based on the calculation result of this calculator. It is a moisture measuring device for powder and granular material.

[0007]

[Operation] The inventors of the present invention made various investigations on the above-mentioned problems for improving the accuracy of the moisture meter, and found that the measurement distance of the moisture meter (distance from the surface of the granular material on the belt conveyor to the moisture meter) Between the measurement accuracy of the meter (the difference between the value measured by the moisture meter and the value measured by the absolute dry test expressed in%),
As shown in FIG. 5, it was found that a long measurement distance causes a negative error in measurement accuracy, and a short measurement distance causes a positive error in measurement accuracy, and has completed the present invention.

That is, according to the present invention, the transport amount of the belt conveyor is continuously measured, and the belt conveyor speed is controlled so that the value is constant. The level can be kept constant, which can improve the accuracy of moisture measurement.

[0009]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side view showing a configuration of an embodiment of the present invention, and FIG. 2 is a view taken along the arrow AA.
In the drawings, the same members as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted. In these figures, 11 is a weighing device, such as a load cell, for measuring the transport amount of the granular material 4, and detects the load of the belt conveyor 1 via a lever mechanism 12 attached to the pulley 2. Reference numeral 13 is a converter for converting the load detection signal. Reference numeral 14 is a speed detector, which is attached to the shaft of one of the pulleys 2 so as to be connected thereto. Reference numeral 15 is a calculator that calculates the transport amount from the load signal from the converter 13 and the speed signal from the speed detector 14.

Reference numeral 16 denotes a controller, which outputs a control signal, for example, a belt conveyor speed adjusting device 18 such as VVVF, in accordance with a deviation between a transportation amount setting signal given from a setting device 17 and a transportation amount measuring signal from a computing device 15. Output to. At this time, the load is preferentially kept within the specified range. The belt conveyor speed adjusting device 18 controls the number of rotations of the motor 3 to adjust the speed of the belt conveyor 1.

In this way, the transport amount of the granular material 4 on the belt conveyor 1 is controlled so that it is always constant because the speed of the belt conveyor changes under a constant load, and the level of the granular material 4 is controlled. Is kept constant, and therefore, the powdery or granular material sorting device 6 is not overloaded, and its damage can be reduced. Width of transporting coal according to the invention
Applied to a belt conveyor of 1.5 m. At this time, the moisture meter used was an infrared moisture meter, which averaged the amount of coal transported.
Controlled at 200 t / h (up to 270 t / h). As a result, the water content in the coal was 5 to 12%, and the transition of the measurement accuracy when measuring the water content is shown in FIG. 3 together with the measurement accuracy of the conventional example. As is clear from this figure, the measurement accuracy according to the example of the present invention is extremely high.

[0012]

As described above, according to the present invention, the transport amount of the belt conveyor is continuously measured and the belt conveyor speed is controlled so that the value is constant. It is possible to keep the level of powder and granules constant. As a result, the accuracy of moisture measurement can be increased, which contributes to the stabilization of products in the manufacturing plant. Further, since the powdery or granular material separating device is not damaged and the powdery or granular material is not dropped from the belt conveyor, there is an effect of reducing the cost required for the maintenance thereof.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a view on arrow AA of FIG.

FIG. 3 is a characteristic diagram showing a transition of measurement accuracy.

FIG. 4 is a perspective view showing a conventional example of a water content measuring device equipped with a powder and granular material sorting device.

FIG. 5 is a characteristic diagram showing a relationship between measurement accuracy of a moisture meter and measurement distance.

[Explanation of symbols]

 1 Belt Conveyor 4 Powder / Granule 6 Powder / Granule Sorting Device 7 Moisture Meter 8 Display 11 Weighing Device 13 Converter 14 Speed Detector 15 Calculator 16 Controller 17 Setting Device 18 Belt Conveyor Speed Adjuster

Claims (1)

[Claims] 1. A belt conveyor for transporting particles such as ores and coal, a moisture meter installed on the belt conveyor for measuring water content in the particles, and a moisture meter installed upstream of the moisture meter. The granular material scraping device that scrapes the surface of the granular material, the weighing device that measures the transportation amount of the granular material, the transportation amount measurement value detected by this weighing device, and the preset transportation amount setting A moisture measuring device for powdery or granular material, comprising: a calculator for comparing and calculating a value and a belt conveyor speed adjusting device for controlling the speed of the belt conveyor based on the calculation result of the calculator.