SU922520A1 - Discrete level indicator - Google Patents

Description

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The invention relates to instrumentation, and more specifically to level gauges for measuring the level of a liquid, and can be used in the petroleum, chemical, oil refining, food and other industries of the industry;

A discrete level gauge is known which contains a permanent magnet float, an encoder in the form of magnetically controlled contacts arranged vertically in a non-magnetic pipe, connected to an encoder and a memory unit, and a display device 1.

The disadvantage of this gauge is the design complexity, i.e. a large number of magnetically controlled contacts are needed, the complexity of their attachment over the entire height of the level, a plurality of leads from them, the magnetically controlled contacts have a limited number of actuations, which affects the operating time of the level gauge, electromagnetic fields are affected by extraneous magnetic fields, which reduces their reliable operation Such contacts can only be made by a specialized enterprise, and they are relatively expensive.

The closest to the proposed invention in its technical essence is a discrete gauge containing a float with a magnet, a transducer for moving the float into an electrical signal made in the form of extended conductors, the number of which corresponds to the number of code bits, and the secondary device, the conductors are made of material experiencing Barkgausen jumps during magnetic reversal 2.

A disadvantage of the known level gauge is that weak frequency signals are obtained at the output of the converter, which require additional amplifying circuits and noise protection devices. In addition, the known level gauge is not reliable enough when operating on contaminated, aggressive fluids, since the transducer is located in a controlled fluid. The purpose of the invention is to expand the range of application and increase reliability. The goal is achieved by the fact that the transducer for moving the float into an electrical signal is enclosed in a hermetic case, which is filled with ferromagnetic liquid with a liquid metal-conducting contact in it. FIG. 1 shows a level gauge, a general view; in fig. 2 - his principle on the electrical circuit; in fig. 3 is a section A-A in FIG. 1. A discrete level gauge consists of a body 1 (Fig. 1) made of a non-magnetic material, and vertical frames 2 placed in a body of an electrically insulating material. On the frames 2 there are copper busbars (strips) 3, the length of which is equal to the height of the measured level. Several tires may be parallel on one frame. On tires 3, electrically insulating stations 4 are applied. Electroconductive portions 5 pass between them (bare bus portions). The insulated and electrically conductive regions have the same length and are arranged alternately between themselves along the entire length of the tire. The lengths of these sections are selected depending on the height of the measured level and the accuracy of measurement. For example, tire 3, extreme left (Fig. 2), is not divided over the entire length of 1 cm lengths. Through, every 1 cm length of the tire is covered with an electrically insulating material (section i), between them is electrically driven section 5. Tire 3, second from the left (Fig. 2), divided into 2 cm lengths. Respectively, the subsequent tires are divided by t, 8,} 6, 32, 64, 128 and 256 cm. One bus 6 is a common contact for all tires and insulation not covered. The tire carcasses 2 are rigidly fixed between each other by spacers 7 (Fig. 3) so that there is a gap between them in which the liquid metal conductive contact moves, for example from mercury, 8. In general, copper tires with insulating sections, ferromagnetic fluid and mercury contact enclosed in a housing form a float-to-electric signal transducer. Outside the housing 1 there is a float 9 with a permanent magnet 10. Inside the housing 1 is filled with ferromagnetic fluid 11 and sealed with a plug 12. From each tire 3 to the indicating device 13 leads I to the tank with the measured liquid level gauge supported by a flange 15. From the power supply 16 to the bus a voltage is applied. FIG. 1 shows the tank 1 with the measured liquid 18. The proposed level gauge works as follows. The level gauge vertically (Fig. 1) is installed in the reservoir 1 with the measured liquid 18 and fixed to it by the flange 15. The float 9, in the absence of the liquid 18 in the reservoir, is in its lowest position. The contact from mercury 8 is also in the lowest position and is located on top of the float E above the magnet 10. This arrangement of mercury is due to the fact that the magnet 10, interacting with the ferromagnetic fluid 11, increases its density so that the mercury floats up top edge of the magnet. When you move the float 9, the mercury will move with it. Each bus 3 of the indicating device 13 is energized from the power source 16. In the case where mercury 8 hits an electrically conductive, section 5 of the bus 3, the electrical circuit is closed in this way: minus the power supply source, conductor V, bus 3 for example left-handed (Fig. 2), mercury contact 8, common bus 6, conductor 1st and plus power supply 16. Similarly, the remaining tires will close. The number of buses is selected according to the selected number of code bits. The conductive areas 5 on the tires 3 correspond to 1, and the insulated O in the corresponding code bits. Thus, at the input of the indicating device 13, a signal 1 or O is supplied from each tire.

The parallel binary code obtained in this manner is processed and fed to digital indicators using known elements. The code combination of the signals at the output of the pointing device uniquely characterizes the magnitude of the level of the measured liquid. The level is measured visually or recorded on special writing devices. When it is necessary to transmit the received information via communication channels, the received binary code is converted to serial.

The discrete level gauge is simple to manufacture and maintain, does not require scarce materials, it has a powerful output signal that is directly converted by tires into a code, and increased reliability due to the presence of mercury contact, ferromagnetic fluid and a sealed enclosure.

The gauge can work with various liquids and successfully combines the advantages of both contactless and contact methods of measuring the level of a liquid.

Claims (2)

1. USSR author's certificate ; № 611118, cl. G 01 F 23/12, 17.05.78. 2. USSR author's certificate 1№ 553 "70, cl. G 01 F 23/26, 15.10.7 (prototype) ..