JPS6059542B2 - Moisture content measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a moisture content measuring device that measures the moisture content of raw materials in a batchya plant by inserting a detection part, and can perform measurements with much higher precision than conventional ones. This invention relates to a moisture content measuring device.

Manufacturing facilities for ready-mixed concrete generally transport several types of raw materials such as fine aggregate, coarse aggregate, and cement from stockyards, silos, etc. to respective raw material storage areas using transport devices such as packet conveyors and belt conveyors. stored in
By opening and closing the discharge gate provided at the bottom of the storage section, a predetermined amount for one batch according to the blending ratio is fed to the measuring section located below the storage section, and the measurement of each raw material is completed. After this, a discharge gate provided at the bottom of the measuring section is opened and the concrete is supplied to a mixer or the like to produce ready-mixed concrete or other products in batch form.

In such a batch plant, in order to manufacture products with a specified quality, it is essential that each batch of raw materials be accurately measured according to the mixing ratio, but in reality, these Raw materials such as fine aggregate and coarse aggregate contain adhering moisture due to raw material washing water or rainwater when receiving the raw materials and during storage, and the weight of the weighed raw materials is the weight that includes this adhering moisture. However, if the ingredients are measured as they are, the initially set blending ratio will not be obtained. Therefore, in order to deal with this, factories that manufacture ready-mixed concrete usually collect representative samples from raw materials such as fine aggregate and coarse aggregate in stockyards and storage areas several times a day, and dry them. The measurement settings for each raw material are corrected based on the moisture content measurement results obtained by measuring the moisture content of the raw materials.

However, a large amount of moisture attached to these raw materials is stored in stockyards. It is not uniformly distributed in raw materials such as fine aggregate and coarse aggregate, and
It is also affected by weather effects such as wind speed, and has a property that changes over time. Therefore, the moisture content of the raw materials fed to the storage section and measuring section varies from time to time.
Moisture content measurements are carried out over several days and times, and even with the measured values, large errors occur in the measurement correction of each batch.
It cannot be said that accurate management of attached moisture is being carried out. In other words, in order to accurately measure a predetermined amount of each raw material, it is necessary to measure at least the moisture content of the raw materials used in the product to be manufactured for each batch. In consideration of production capacity and the like, for example, in a ready-mixed concrete production plant, it is necessary to quickly measure the moisture content within a few seconds to about ten-odd seconds.

In this case, a capacitive moisture content measuring device that measures the moisture content of the sample by inserting a detection part with a high-voltage electrode in the center and a ground electrode around it into the raw material and measuring the capacitance between both electrodes. It is effective to apply However, some of the raw materials used in manufacturing plants, such as fine aggregate used in ready-mixed concrete manufacturing plants, contain 5wI! t
Some of the following particles of different sizes are mixed and have a moisture content in the range of several percent to over ten percent, and the moisture percentage of the raw material can be measured by inserting the moisture percentage detection part of the moisture percentage measuring device. When measuring, particles may adhere to the electrode of the inserted detection part due to moisture adhering to the surface of the powdery raw material, and even if the detection part is returned after measuring the moisture content of the raw material, the electrode of the detection part may not be attached. The particles remain fixed. Even if the moisture content detection part with particles still attached is inserted into the raw material that has been weighed for each batch, the raw material to be measured in the measurement part and the electrode of the moisture meter detection part as described above may not be connected to each other. Differences in the moisture content of the adhering raw materials and the degree of filling cause errors in the measured values, making it difficult to accurately measure the moisture content of the raw materials in the measuring section. Furthermore, the amount of powdery raw material that sticks to the detection part increases as the number of times the detection part is inserted increases. As the number of measurements increases, errors in the measured values of moisture content accumulate. The object of the present invention is to detect the moisture content of a moisture content measuring device that is inserted into raw materials for the purpose of measuring the moisture content of powdered raw materials that have been weighed to a predetermined set amount. To provide a moisture content measuring device that can quickly, simply and accurately measure the moisture content of a raw material by removing the raw material attached to the detection part using physical means before or after inserting the detection part. be.

An embodiment shown in the drawings will be described below.

A frame 1 is fixedly or removably attached to the side wall of a metering section 3 filled with raw material 2, and stands erect near the ends of this frame 1 with columns 4, 4 spaced apart from each other. ) is a hydraulic reciprocating device whose one end is pivotally connected to the pillars 4, 4 with pins 6. A reciprocating piston (not shown) is provided in the fluid cylinder 7 of the fluid pressure reciprocating device, and a moisture content detector 9 is fixed to the tip of an arm 8 connected to the piston and extending outside the fluid cylinder 7. This moisture content detection part 9 has a high voltage electrode 10 in the center, and a ground electrode 1 around this high voltage electrode.
1, and each electrode has a needle shape. A spring 1 is installed between the lower surface of the tip of the fluid cylinder 7 and the frame 1.
2 is inserted, and the fluid cylinder 7 is always deflected counterclockwise around the pin 6 by the elasticity of the spring 12.

13 is an electric motor supported on a stand 14 on the frame 1. Reference numerals 15 and 16 refer to other columns provided at a distance from each other on the frame 1 approximately in the middle between the columns 4 and 4 and the measuring section 3, and pivotally support cams 17 and 17 by shafts 16. .

A gear 18 is fixed to one end of the shaft 16 and meshes with a gear 19 driven by the motor 13. However, as is clear from the illustration, the cams 17, 17 are located on both sides of the fluid pressure reciprocating device.

20, 20 are in contact with the cam surfaces of both the cams 17, 17 with pins provided on both sides near the tip of the fluid pressure reciprocating device u.

21 is a hammer stand provided on the frame 1, and 22 is a hammer that faces the hammer stand and protrudes from the lower surface near the tip of the fluid pressure actuated device.

Reference numeral 23 indicates an insertion hole for the moisture content detection section 9 provided in the side wall of the measuring section 3.

Next, the operation of the moisture content measuring device of the present invention will be described.

First, when it is notified, for example, by an appropriate electric signal, that the measurement of a predetermined ratio of the measurement set value of one batch of raw materials 2 according to a predetermined mixing ratio has been completed, the fluid cylinder 7 is immediately activated. When activated, the internal piston slides to insert the moisture content detection unit 9 forward into the raw material 2 through the insertion hole 23 in the side wall of the measuring unit 3 via the arm 8, and between the electrodes 10 and 11 of the moisture content detection unit 9. The moisture content of raw material 2 is measured by measuring the capacitance of the raw material at . Next, once the moisture content of the raw material 2 has been measured, the fluid cylinder 7 is operated in the opposite manner to the above, and the moisture content detection part is pulled out from the raw material 2 in the measuring part 3 and returned to its original position, completing the moisture content measurement. . Next, by driving the electric motor 13, the cams 17, 17 attached to both ends of the camshaft 16 are rotated via the gears 19, 18, and the pins 20, 20 are pushed up along the cam surface. The fluid pressure reciprocating device moves from the solid line position to the dotted line position against the elastic force. Furthermore, as the rotation of the cams 17, 17 progresses, the pins 20, 20 are removed from the tops of the cams 17, 17, and due to the return force of the spring 12, the hydraulic reciprocating device u
returns to the solid line position. At this time, the hammer 22 hits the hammer stand 21 fixed to the frame 1, giving a strong impact to the fluid pressure reciprocating device u, scattering the raw material particles adhering to each electrode of the moisture content detection section 9, and cleaning the electrodes. The raw material 2 is wiped and prepared for measuring the moisture content of the raw material 2 to be weighed into the measuring section 3 in the next batch. When , the electric motor may be stopped for each shock. You may continue to rotate so as to give impact several times. A series of these operations can be performed automatically in conjunction with each other using appropriate electrical signals, and the amount of water adhering to the raw material 2 in the measuring section 3 can be calculated using the moisture content measurement value obtained through such operations. It can be calculated and corrected to the correct mixing ratio. As described above, by using the moisture content measuring device of the present invention, it is possible to eliminate measurement abnormal values due to the moisture content detection part of the raw material sticking to the electrode, improve the accuracy of moisture content measurement, and reduce the mixing ratio due to the moisture attached to the raw materials. Correction can be performed quickly, easily and accurately.

Further, in the moisture content measuring device of the present invention, the fluid cylinder may be configured to use a mechanical reciprocating mechanism or the like in addition to using air pressure or oil pressure.

The use of the electrode of the moisture content detection section is effective in improving the accuracy of the moisture content measurement value, and by using this moisture content measurement value, it is possible to more accurately correct the proportion of the raw material due to attached moisture. As described above, the moisture content measuring device according to the present invention eliminates abnormalities in measurement values caused by sticking of raw materials to the electrodes of the moisture content detection unit, and can quickly, easily, and accurately measure the moisture content of raw materials. It is.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an embodiment of the moisture content measuring device of the present invention, and FIG. 2 is a schematic front view thereof. DESCRIPTION OF SYMBOLS 1... Frame, 2... Raw material, 5... Reciprocating device, 9... Moisture content detection part, 10, 11... Electrode, 1
7,17...cam, 20,20...pin, 21...
・Hammer stand, 2200●hammer.

Claims (1)

[Claims] 1 A reciprocating device consisting of a measuring section filled with powdery raw materials, and a frame connected to this measuring section, facing the measuring section, pivoted at one end, with a hammer on the bottom surface near the other end and a pin on the side surface. a moisture content detection section connected to the reciprocating device and having an electrode that goes in and out of the measuring section; a hammer stand provided on a frame opposite to the hammer; A moisture content measuring device consisting of a hammer and a cam that applies an impact to the moisture content detection part through the hammer base.