CN2141075Y

CN2141075Y - Static-pressure level indicator for sealed containers

Info

Publication number: CN2141075Y
Application number: CN 92235899
Authority: CN
Inventors: 徐宏宇
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-27
Filing date: 1992-10-27
Publication date: 1993-08-25
Anticipated expiration: 2002-10-27

Abstract

The utility model relates to a static-pressure liquid level meter for sealed containers, which is composed of a thin-wall tube and a silicon cup arranged inside the thin-wall tube. The upper part and the lower part of the silicon cup are provided with capillary steel pipes which are used to be filled with pure silicone oil, the upper end and the lower end of the capillary steel pipe are respectively provided with a metal corrugated isolation diaphragm which is used for transferring the pressure of gas and liquid; a ventilating hole is opened on the upper part of the thin-wall tube, and the ventilating hole leads gas pressure into the container and prevents the gas from condensing. The liquid level meter has the advantages of high measuring accuracy, simple structure and easy installation, and can be directly installed in the sealed container to measuring the liquid level heights of an oil tank, a liquid gas storage tank and a non-corrosive liquid storage tank.

Description

Static-pressure level indicator for sealed containers

The utility model belongs to a kind of closed container pressure-type liquidometer, specifically is used to measure the device of the closed vessel liquid level height that has static pressure, and described closed container comprises: oil tank, liquid gas storage tank and non-aggressive receiver.

Measure closed vessel liquid level in China and just typically use differential pressure transmitter; it is by the high pressure of measuring container bottom liquid and the low pressure of measuring gas above the vessel liquid; determine the height of liquid level by height pressure reduction; its shortcoming is to be difficult in use install; and this transmitter needs overload protecting mechanism, complex structure.

" petroleum refining " 91 year second phase reported that the U.S. adopts a kind of 2-3 pressure transducer to measure the device of closed container, one of them sensor is contained in closed container top and is used to measure gaseous tension on the liquid level, another sensor is contained in the pressure that container bottom is used to measure liquid bottom, obtain two pressure differentials, the 3rd sensor is contained in the container middle part and is used for the density correction, the advantage of this method is new instrument, can finish the level gauging of closed container with ready-made 3 pressure transducers, this apparatus structure is simple to be used easily, shortcoming is the poor accuracy of measuring, as the internal tank static pressure is 2MPa, and liquid specific gravity is 0.7 gram per centimeter ³The degree of depth is 10 meters to the maximum, then the range of first measurement gas pressure transducer should be 2MPa at least, and the range that is placed on second liquid-pressure pick-up of bottom only should be 2.07MPa less, and liquid level is from 0 meter to 10 meters, and the variation of the pressure of sensor has only 0.07MPa, the precision of sensor generally is meant completely putting the relative accuracy of Cheng Eryan, so just the actual measurement precision is had a significant impact, from above-mentioned example, descended 30 times of 2.07/0.7 ≈ of its measuring accuracy.

The purpose of this utility model has provided a kind of measuring accuracy height, is directly installed in the closed container, closed container pressure-type liquidometer easy to install.

The closed container pressure-type liquidometer, comprise thin walled tube, pressure measuring element one silicon cup is housed in this thin walled tube, make 4 variable resistor R1-R4 by diffusion technique in this silicon cup, transmit measured pressure signal with the electric bridge form, the signal that is measured shows liquid level after sealing wire is delivered to secondary instrument or Computer Processing, capillary tubing is equipped with in upper and lower at silicon cup, filling is used to transmit the pure silicone oil of gas and fluid pressure in the capillary tubing, the metal profiling liner of supporting wavy metal isolation diaphragm is housed respectively at the capillary tubing two ends, the wavy metal isolation diaphragm is used to transmit gas, fluid pressure; thin walled tube top has air hole; purpose is to introduce the gaseous tension in the closed container, and prevents ripple isolation diaphragm condensation is to improve measuring accuracy.The ring flange that is used for connection is equipped with in the thin walled tube upper end.The length of thin walled tube is identical with the height of closed container.

The utility model and its advantage of existing closed container measurement mechanism comparison are:

1, the not influence of the interior static pressure size of receptor of measuring accuracy, thus measuring accuracy improved;

2, this liquid level gauge is simple in structure easy for installation, can directly be contained in to hold to close in the container;

3, this liquid level gauge also can be used for measuring liquid specific gravity, uses as picnometer.

Description of drawings:

Fig. 1 is a closed container pressure-type liquidometer structural representation;

Fig. 2 is 4 variable resistor R1-R4 electric bridge synoptic diagram of diffusion profile in this liquid level gauge silicon cup.

Number in the figure: 1, secondary instrument or computing machine; 2, sealing wire; 3,10, ripple isolation diaphragm; 4,9, profiling liner; 5,8, capillary tubing; 6, silicon cup (strain diaphragm); 7, thin walled tube; 11, ring flange; 12, air hole; 13, glass; 14, box hat.

Below in conjunction with description of drawings the utility model specific embodiment:

The closed container pressure-type liquidometer comprises: thin walled tube 7; pressure measuring element one silicon cup 6(strain diaphragm is housed) in this thin walled tube; in this silicon cup, make 4 variable resistor R1-R4(and see Fig. 2) by diffusion technique; 4 variable voltage dependent resistor (VDR)s connect into Wheatstone bridge; in when, when strain diaphragm two surface pressures difference deformation taking place; R1; the R4 resistance changes; when a diagonal line making alive U of electric bridge; another diagonal line just has signal V output; this signal is directly proportional with the pressure differential at two ends up and down; the silicon cup rear portion is lined with glass 13; this glass can be used for prevention because temperature variation causes that deformation is inhomogeneous; cause the resistance variations scrambling; in silicon cup outer rim envelope box hat 14 is arranged; be used to protect silicon cup not to be damaged; the capillary tubing 5 of the pure silicone oil of filling is equipped with in the upper and lower of silicon cup; 8 are respectively applied for gas and the fluid pressure that transmits closed container; in kapillary 8 upper ends and kapillary 5 lower ends metal profiling liner 9 is housed respectively; 4; at the distolateral wavy metal isolation diaphragm 10 that is equipped with respectively of this profiling liner; 3; this wavy metal isolation diaphragm 10; 3 are used to transmit gas and fluid pressure; have air hole 12 on thin walled tube 7 tops; air hole is the gaseous tension that is used to introduce in the closed container; and can prevent the ripple isolation diaphragm; condensation influences measuring accuracy; at thin walled tube upper end dress ring flange 11; with ring flange 11 this liquid level gauge is installed in below the loam cake of closed container, the length of thin walled tube is identical with the height of closed container.Circuit is connected with outside secondary instrument or computer processor unit by sealing wire 2 on the silicon cup, demonstrates liquid level in the closed container after the pressure signal that measures is delivered to secondary instrument or Computer Processing.

Claims

1, a kind of closed container pressure-type liquidometer is made of thin walled tube 7 and pressure measuring element one silicon cup 6 that is contained in the thin walled tube, 4 variable voltage dependent resistor (VDR) R1-R4 that in silicon cup, make with diffusion technique, 4 voltage dependent resistor (VDR)s are connected into Wheatstone bridge, the silicon cup back is lined with glass 13, be used for prevention and cause that because of temperature variation deformation is inhomogeneous, in silicon cup outer rim envelope protection box hat 14 is arranged, on silicon cup, be connected with sealing wire 2, be connected with the secondary instrument or the computer processor unit of outside by the sealing lead-in wire, it is characterized in that being equipped with the pure silicone oil capillary tubing 8 of filling in the upper and lower of silicon cup, 5, in capillary tubing 8 upper ends and capillary tubing 5 lower ends the wavy metal isolation diaphragm 10 that is used to transmit gaseous tension and fluid pressure is housed respectively, 3, have air hole 12 on thin walled tube 7 tops;

2, according to the described liquid level gauge of claim 1, it is characterized in that wavy metal isolation diaphragm 10,3, be contained in respectively on the metal profiling liner 9,4;

3,, it is characterized in that being equipped with and be used to be connected and installed with ring flange 11 in this thin walled tube upper end according to the described liquid level gauge of claim 1.