SU823975A1 - Hydrostatic densimeter - Google Patents

Description

The invention relates to a technique for measuring the density of liquid media by the hydrostatic method and can be used in the chemical, petrochemical and other industries. A hydrostatic fluid density meter with automatic temperature compensation is known, the sensitive element of which is made as a block of bellows of low rigidity and equal effective areas, and the bellows are installed at various points of the L-shaped pipeline section. The output node of the bottom irepe spacing (to the displacement sensor) ) consists of two bellows interconnected by a disk and a stand, placed in the cavity of the lower measuring bellows I. The disadvantage of the known densitometer is its low feelings telnost due to friction in the movement transfer mechanism silfszha bottoms. The closest to the technical essence of the present invention is a hydrostatic densitometer, in which the displacement sensor is made in the form of two cylindrical electrodes mounted inside an electrode body, on which vertically the bases are located in opposite sides of the bellows, at the center of each of which is a rod, fixed to the bottom of the bellows, and the other end of which is made of a dielectric; located between the electro-dami displacement sensor. A capacitor is switched on to compensate for temperature variations in the density of the fluid, parallel to the displacement sensor. This capacitor consists of an electrode housing, on which a dielectric ring is located with an external sensor, and an external electrode 2 is attached to the ring. The disadvantage of the densitometer is that the base of the instrument (the distance between the lengths of the housing) electrode and can not be promptly changed when setting up a meter or moving to another range of 38. Measurement, hook as it requires reconstruction of the density meter. Another disadvantage of the area is that in a narrow range of densities (O – OO kg / m), due to a decrease in the bellows stroke. The sensitivity of the meter is reduced. The purpose of the invention is to simplify the adjustment of the base of the densitometer and its sensitivity. The goal is achieved by the fact that a hydrostatic density meter containing a block of low-rigidity bellows and equal effective areas consisting of a body with opposite backgrounds and a cylindrical capacitive displacement transducer located on non-bottoms in opposite directions with a dielectric installed between them, as well as rods connecting the bottom of the bellows with converter elements, is additionally equipped with a second block of bellows, located parallel to the first th block and the connecting rod, wherein the bellows blocks mounted at the ends of the rod perpendicular to its rno oci wherein the rods in each block are connected to respective elektrodamipreobrazovateley, internal electrodes are covered with dielectric and electrode transducers are in the form of telescopic tubes. In addition, the bottom bellows of the lower blind are made bimetallic with an inner-facing layer. The drawing shows schematically v the hydrostatic density meter proposed. The density meter contains two blocks of bellows located on the rod 1, the block of bellows is attached to the rod {representing the pipe) using connectors 2 and 3 mounted on cylindrical bodies 4 and 5 of these bricks made of dielectric. The axes of the blocks And Qj-0 are parallel to each other and perpendicular to the axis m - t of the rod. The upper block consists of a body and bellows 6 and 7 of low rigidity fixed on it and equal effective areas. To the bottoms of these bellows, the electrodes Yu and 11, which are fully inserted coaxial cylinders, are reinforced with rods 8 and 9, the outer surface of the inner cylinder 10 being covered with dielectric 12. The rod 9 connecting the outer electrode to the bottom of the bellows 7, when the block 75 is compressed, the inner electrode moves to the space behind the outer electrode 11. The electrical contact with the electrodes of the upper block is carried out using contacts 13 and 14, made in the form of rings installed inside the core whisker and having electrical contact with the bellows 6 and 7 in their places of securement. The second unit of the meter density meter consists of a dielectric body 4, with bellows 15 and 16 fixed on it, the bottoms of which 17 to 18 are bimetallic and with the active layer turned inwards. To the bottom: with the help of rods 19 and 2O, cylindrical, coaxially located electrodes 21 and 22, completely separated from each other, are reinforced, the outer surface of the internal electrode 21 is covered with a dielectric 23. The rod 19 of the internal electrode is installed so that it does not interfere with the introduction of cylindrical electrodes 21 and 22 into each other. Electrical contact with the averaging electrodes is made through conductive rings 24 and 25. The densitometer sensor is mounted in a capacitor using a tube 26, which passes the connecting wires and the internal cavities of the bellows blocks communicate with the atmosphere. The density meter works as follows. During vertical-immersion of the densitometer using a tube 26 in a container with a controlled fluid, a hydrostatic column of the controlled fluid is exerted on the bottoms of the bellows blocks. I) To the center of the bottoms of the bellows 6 and 7 of the upper block and height + - b To the center of the bottoms of the bellows of the lower block. Moreover, with the horizontal arrangement of the axial blocks of the bellows, the relative displacements of the electrodes Yu, 11 and 21, 22 under the action of pressure 9V Pa 97Снн ;, respectively, are e ,. and AQ-RM e., V where e .. t-, -relative displacements of the electrodes 10.11 and / 21.22, respectively; - movement of each of the bellows 6 and 7 of the upper and each of the bellows 15 and 16 of the lower block, respectively; - density of the controlled fluid; -the base of the instrument (distance between the centers of the bottoms of the sylphs of the blocks); EF - effective area sil, fonav 6,7,15 and 16; -9.81 m / s - acceleration of free fall; - thickness of the corrugation wall; - module of elasticity of the material of bellows; h is the number of corrugations; K is the outer diameter of the bellows; Hell is the calculated coefficient depending on the ratio. At a relative displacement, under the action of the hydrostatic pressure of the controlled fluid of the electrodes 10 and 11, the capacitance C formed by them and the dielectric 12 of the capacitor decreases according to a ratio of 0.5fo- (ee-) : euJ ± g :: „aa

Where

-the inner diameter of the elec-a type 11, cm;

(- dielectric thickness, CM

- outer diameter of the electrode is 10 cm;

g is the dielectric constant of dielectric 12; -, - the length of the electrodes, cm; 6 - capacitance of the converter of the upper bellows block; ka, pf.

Simultaneously with a decrease in capacitance C, as a result of the hydrostatic column of the controlled fluid on the lower block of bellows, the electrodes 21 and 22 move counter to face, as a result of which the capacitance of the transducer formed by these electrodes and dielectric 23 increases

0.56-62.

(four)

.e., en

aa

cl,

where C, is the capacitance of the transducer formed by electrodes 21, 22 and dielectric 23. The remaining dimensions of electrodes 21, 22 and dielectric 23 and their designation are the same as those of electrodes 10, 11 and dielectric 13. 823975 is true pre Po (1 call of vve

rewrite (6 /) in the form

With A + B-f. (7)

From the expression (7) it can be seen that the total capacity of the converter depends linearly on the density of the liquid under study.

ti, and the sensor sensitivity of the sensor is dense .. (- - B) is twice the sensitivity of the known sensor due to two large opposite displacements of the electrodes 10.11 and 21.22.

To change the base L of the densitometer, it is necessary to remove rod 1 and connect 2.3 and install another rod in its place of the required length. Pointer operation takes a little time n

It is possible to quickly adjust the density meter for any measurement range by selecting the length of the rod 1. To compensate for temperature variations in the density of the densitometer, it is proposed to use

in the lower block of the snfon 15 and 16, bimetallic bottoms 17 and 18 with the active layer inside the block, the operation of which is carried out as follows.

Claims (2)

As the temperature of the controlled medium increases, the total capacity of the converter decreases due to a decrease in the density of the medium, however, as the transducers of its displacement and the lower block of bellows are parallel to each other, then the total capacity of the sweeper is o, 5fo-ce + (ea-e) l - ep-i1 ±: 4e „. ec5t.d + ld (5) ratios. Aviv in the expression and (2) for B and e 2 after the transformations we get 0 ... . and J. l. 11LL. Cha + a-c 3 l-c designations. e, 3, j2: ± 4en. ., za-n1 .H-25- en-6ta.- d 78 ativative with 1Oi dn-17 and 18 expanding, more than passive, bends, moves the electrodes 21 with the help of pins 19 and 2O, towards each other, which leads to increase the total capacitance of the converter and compensates for the temperature change in the density of the controlled fluid. . The large-scale density meter of a liquid allows for the prompt adjustment of the base of the meter and increase its sensitivity. In addition, the sensor of the densitometer in the form of two structurally separate units simplifies its repair and operation. Claims 1. A hydrostatic density meter containing a sylph block of low rigidity of equal effective areas, consisting of. enclosures, with bottoms located on it in opposite directions with phonics, cylindrical capacitive displacement transducer, formed by external and internal electrodes, with Dielectric installed between them, as well as rods connecting the bottom of the bellows with transducer elements, characterized in that to simplify the adjustment of the base of the plateau and increase its sensitivity, the densitometer is additionally equipped with a second sylphage block, located parallel to the first block and the connecting rod, The sylphonic blocks are installed perpendicular to its axes at the ends of the shaft, with the rods in each block connected to the corresponding transducer electrodes, the internal KOTqjbK electrodes are covered with a dielectric, and the transducers electrodes are made in the form of telescopic tubes. 2. The densitometer according to claim 1, .o t l and h a and y and the fact that the bottoms of the lower blocks of the lower blocks are bimetallic, with the active layer facing inward. Sources of information taken into account in the examination 1. USSR author's certificate number 177142, cl. Q 01N 9/26, 1964. 2.ABTqjcKoe certificate of the USSR in application no. 250929О ,. cl. Q 01 N 9/26, 1977.