KR20110122079A

KR20110122079A - Weight measuring method to strain gauge attached directly to the post or supporting point of the silo

Info

Publication number: KR20110122079A
Application number: KR1020110105677A
Authority: KR
Inventors: 한상근
Original assignee: (주)평화하이텍
Priority date: 2011-10-17
Filing date: 2011-10-17
Publication date: 2011-11-09

Abstract

PURPOSE: A method of measuring the weight of stored goods by directly attaching strain gauge to a silo post or a support point is provided to enable easy stock management by measuring the amount of raw materials using weight for silo for any shapes of raw materials. CONSTITUTION: A method of measuring the weight of stored goods by directly attaching strain gauge to a silo post or a support point is as follows. A strain gauge(13) and a temperature compensating gauge(14) are directly attached to the strain gauge point of the surfaces of a plurality of support posts(4). The support post supports a silo tank. A wheatstone bridge circuit is formed. The wheatstoen bridge circuit of each support post is formed in parallel. The wheatstone bridge circuit is connected to a wire terminal(15). Weight converted into a digital signal by an amplifying indicator(17) through a signal wire(16) is directly measured.

Description

Weight measuring method to strain gauge attached directly to the post or supporting point of the silo

The present invention uses a load measuring device called a load cell at the bottom of the silo or the bottom of the silo to measure the weight of the raw material stored in the silo or the hopper, but in the case of silos in which hundreds or thousands of tons of raw materials are stored, the load cell is a load measurement. It is impossible to install the device. Therefore, in order to solve this problem, the strain gauge used for load cell fabrication or stress measurement is directly attached to the bottom of the silo and the hopper column, and the Wheatstone bridge circuit is used to apply the voltage to the indicator to amplify the minute output signal. It relates to a method of measuring the amount of raw material stored inside a silo or hopper storage tank which is converted into a digital signal to display the weight of the silo and is used by a computer to manage aggregate raw material inventory.

In the conventional method for measuring the weight of raw materials stored in the silo or the hopper, as shown in Figs. Was set to measure the weight value stored in the silo. However, the above method could be applied to silos storing raw materials of 100 tons or less, but in the case of silos reaching more than 100 tons to thousands of tons, installation and use of the load cell is difficult due to difficulties in the production and installation of the load cell. Accordingly, in order to measure the amount of raw material stored in a large silo, the storage height of the raw material is measured to determine the stock state of the raw material. For this purpose, an ultrasonic level or a descending level is installed at the top to measure the height of the raw material. In terms of the amount of raw materials stored in the silo has been calculated. However, the measurement method of the raw material is a reality that the error rate of the measured value has to be measured with an error range of 10 to 20% because the height of the raw material is different from the input and discharge of the silo. In addition, in the initial stage of installation, the operation state of the measuring device is smooth, but silos in which dust or moisture-containing raw materials (coal, etc.) are stored may not be used much, and frequent errors and failures occur. In addition, the strain detector 11 of FIG. 3 may be attached to the silo column 4 in the form of measuring the stress or weight of the structure as in Patent Registration No. 10-10375026 and Utility Model Registration 20-0450259. In the case of silos installed outdoors where the storage capacity is desired, the temperature change rate 12 of the main body pillars 4 and the detection device 11 of the structure is changed in the place where the weather or the environment changes, such as when the morning sun rises and when the sun rises. Even though there are no inputs and discharges of stored raw materials inside the silo, the weight value indicated has a problem that the weight continues to change due to the different material expansion rate due to the temperature change between the measuring object and the measured object. As a result, the stock weight of the raw material in the evening and the stock weight in the morning were a big obstacle to ensuring reliability. Accordingly, in order to suppress the weight change with respect to the temperature while installing the product of the registered patent, the temperature compensation for the stability of the weight at the time of installation, such as temperature compensation for the track, temperature compensation for the detection device and material, and insulation of the detection device, Efforts have been made, but in the situation where full temperature compensation is impossible, the invention has been invented the method of measuring the weight of the present application method in order to eliminate the inconvenience of installation, the change of weight value according to the environment and the waste of time for temperature compensation.

Patent Registration 10-0375026 Utility Model Registration 20-0450259

The present invention has been developed for the purpose of securing the reliability for indicating a stable weight value against external temperature changes as described in the background art, and directly supports and supports the strain gauge to the pillar or support beam of the silo and the bottom of the outer wall. The idea was to build a load cell into the structure itself. In addition, to realize this, after polishing the surface of the pillar or support point of the silo as shown in FIG. 4, the strain gauge and the temperature compensation gauge are attached with adhesive, and the Wheatstone bridge circuit as shown in FIG. 5 is connected to make a load cell for each column. As shown in FIG. 6, the entire circuit is connected to the wiring instruction indicator in a parallel circuit to convert the digital signal into a digital signal, thereby eliminating the source of temperature difference generated between the pillar to be measured and the detector to be measured. The purpose of the present invention is to completely solve the change in the indicated value according to the difference in temperature expansion rate generated in the gravimetric field method using the strain detector of FIG. When using a method of measuring the weight of the raw material stored in the silo is attached to the strain gauge directly on the silo pillar as in the present invention to the ambient temperature change occurring between the silo support pillar 4 and the deformation detector 11 of FIG. The fluctuation of the indicated value due to the difference in temperature expansion rate between the measured object and the measured object disappears and it has the same effect as installing a load cell on the storage column of the silo, so that a stable and accurate weight value is not required without additional temperature compensation. Maintenance and the elimination of time-consuming and troublesome installations.

The present invention is a strain gauge that can measure the physical deformation of the support column that changes with weight for the purpose of minimizing the weight fluctuation and the error caused by the external environmental temperature that appears as a problem of the silo weighing apparatus directly under the column Or by attaching to a support point to obtain a stable indication of the weight.

The direct attachment of strain gauges to the support points of silos or hopper storage tanks makes the support points themselves load cell, a weighing sensor, which is very stable to eliminate temperature fluctuations due to temperature by attaching existing modular sensors. Weighing method can be used to measure the amount of raw materials stored in any type of raw material storage silos, such as silos, hoppers and cylindrical silos, which have never been measured by weight. It is a way.

1 is a conventional silo storage measuring apparatus diagram
2 is a conventional hopper storage measuring device diagram
3 is a device diagram for measuring the stress of the structure using a conventional strain detector
Fig. 4 is a diagram in which a strain gauge is attached to a support column or a support point surface
5 is a schematic diagram of a Wheatstone bridge circuit of a strain gauge resistor.
6 is a connection diagram of a plurality of Wheatstone bridge circuits connected to the indicator indicators.
Figure 7 Weighing diagram of the strain gauge attached to the surface of the cylindrical silo
8 is a field installation diagram according to an embodiment of the present invention
9 is a field picture according to an embodiment of the present invention

The method for realizing the present invention is described in detail with the support column 4 and the support beam 8 installed for the support of the existing silo or hopper storage tank 1, 2 shown in FIGS. 1 and 2. In order to directly attach the strain gage to the surface of the strain gage attachment point 25 at the bottom of the cylindrical silo of 7, the strain gage 13 and the temperature compensation gage 14 are bonded to each other as shown in FIG. A Wheatstone bridge circuit as shown in FIG. 5 is connected to the terminal wire 15 for constituting the wiring, and the signal line 16 is drawn out, and the minute output signal generated therein is converted into an amplified digital signal by the indicator 17 of FIG. Compiling with the computer 18 of FIG. 8 The weight value of the storage raw material 3 stored in the silo raw material storage tank 1 of FIG. 1 or the hopper storage tank 2 of FIG. 2 and the cylindrical silo 26 of FIG. Will be identified. The Wheatstone bridge circuit shown in FIG.

The equilibrium condition is achieved, and the output voltage becomes 0 even if a constant voltage is applied at both ends. However, when deformation occurs due to the weight of the storage raw material 3 on the support column 4 or the support beam 8 to which the strain gauge is attached, the length of the strain gauge 13 is changed, thereby causing a resistance change. At this time

An output voltage 22 is generated such that the weight is converted to the digital signal by the indicator indicator 17 using the same. In addition, the attached strain gage 13, the temperature compensation gage 14 and the terminal block 15 are primarily protected from waterproof and moistureproof by silicon, and the waterproof case 19 of FIG. Covered and fixed with bolts and the sealing 23 with silicon in contact with the surface of the pillar to protect from the outside at the same time waterproof and to form a cover 20 on the front of the waterproof case to be able to repair and check.

1. Silo storage tank 2. Hopper storage tank
3. storage raw material 4. supporting pillar
5. Load Cell 6. Foundation
7. Support base 8. Support beam
9. Support Bracket 10. Fixing Bracket
11. Deformation detector 12. Temperature expansion direction
13. Strain gauge 14. Temperature compensation gauge
15. Terminal block for wire drawing out 16. Signal line
17. Indication indicator 18. Computer
19. Waterproof Case 20. Waterproof Case Cover
21. Voltage applied 22. Output voltage
23. Silicone Sealing 24. Communication Line
25. Strain Gage Attachment Points 26. Cylindrical Silo

Claims

Strain gauges 13 and temperature compensation gauges 14 are directly attached to the surface of the strain gage attachment points 25 of the plurality of support columns 4 supporting the silo storage tank 1 and constitute a Wheatstone bridge circuit. After constructing the Wheatstone bridge circuit of the support column in parallel circuit and connecting it to the wire drawing terminal block 15 and directly measuring the converted weight from the amplifying instruction indicator 17 to the digital signal through the signal line 16

The strain gauge 13 and the temperature compensation gauge 14 are directly attached to the surface strain gauge attachment point 25 of the support beam 8 supporting the hopper storage tank 2 to form a Wheatstone bridge circuit. After constructing the Wheatstone bridge circuit of the support column as a parallel circuit and connecting it to the wire drawing terminal block 15 and directly measuring the converted weight into a digital signal in the amplifying indicator indicator 17 through the signal line 16.

A strain gauge 13 and a temperature compensation gauge 14 are directly attached to the lower surface of the strain gage attachment point 25 of the cylindrical silo 26, and a Wheatstone bridge circuit is formed to form the Wheatstone bridge circuit of each support column. After the parallel circuit is configured, it is connected to the wire drawing terminal block 15 and directly measures the converted weight into a digital signal in the amplifying indicator indicator 17 through the signal line 16.