SU922521A1 - Bell-type capacitive dynamic plant for measuring consumption - Google Patents

Description

(5) BELL VOLUME AND DYNAMIC FLOW MEASUREMENT INSTALLATION

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The invention relates to a measurement technique, and more specifically to a device for bell-type flow measuring installations for calibrating and calibrating gas meters and flowmeters.

There are known installations for the calibration and calibration of gas meters and gas flow meters, created on the basis of bell-shaped gas meters with a weight method of compensating for the weight loss of a bell, caused by the Archimedean force that occurs during the process of immersing its walls in the barrier fluid 11.

A weight compensating device in such installations, for example, a chain one with a uniform weight distribution along the chain length, almost completely ensures the constancy of pressure P under the bell during its working stroke under the condition of a constant cross-sectional area F of the bell

p - f. ,

where G is the weight of the bell.

But due to the complexity of manufacturing cylinders of large diameters and volumes, the cross-sectional area of the bell in height in such installations is usually not constant. Even an insignificant deviation of the cross-sectional area F leads to a change in air pressure under the bell, which is not compensated by a chain with an even weight distribution along the length and therefore causes a measurement error.

IS

Claims (2)

A bell-bell volumetric flow-measuring installation for gas is also known, in which compensation for the uncertainty of pressure under the bell during its operation is carried out by connecting the sub-column space with a membrane actuator, the rod of which is connected to the contact bar of the contact bar through a lever 39 . Compensation for the uncertainty of pressure in such an installation is achieved by moving the current collector contacts up or down along the contact bar, depending on the magnitude and sign of the resulting pressure change under the bell. Such an installation contains a complex compensating device consisting of a membrane actuator with a rod, a lever and movable contacts 2. However, this device can compensate for the error only if the pressure along the bell increases or decreases evenly throughout the bell. If, however, a random change in pressure occurs in the installation, caused, for example, by a local deviation of the cylindrical OT bell shape, such a device will not be able to make an appropriate correction. In addition, the presence in the device of a large number of elements leads to a decrease in speed and sensitivity. The purpose of the invention is to improve the accuracy of the installation by compensating for changes in pressure under the bell caused by deviations of the bell shape from the cylindrical one. This goal is achieved by the fact that, in a well-known bell-shaped dynamic-flow-metering installation containing a bell immersed in liquid, a contact ruler, a chain with a counterweight, a temperature compensation device and a pressure change compensation device are made in the form of additional weights locally placed on the compensation bar. chain, and the weight of gro. The call is selected in accordance with the condition of maintaining a constant p-ratio at non-permanent F, where G is the weight of the bell, F is the area of the local section of the bell, and the distances between the weights are selected in accordance with the distances between the local deviations of the cross-sectional area bells. The figure shows the proposed bell-tower volumetric flow-measuring installation for accurate reproduction and measurement of gas flow, general view. The installation has a bell 1, immersed in a liquid, to which, with the help of steel tape 2, thrown over the blocks 3, the contact bar 5 is suspended. Under the bell there is a thermo-bottle 6, connected by a pulse tube 7 with an actuator 8, the rod 9 of which is a lever 10- the current collection contacts 11 are driven. By moving them along the contact bar, only the temperature error of the installation is compensated. Fan 12 through the valve 13 air is supplied under the bell. The outflow of air from under the bell when calibrating or calibrating the device H is carried out through valve 15. The action of the buoyancy force is compensated by a circuit 16 that is thrown over blocks 17 and 18. The instability of the pressure under the bell caused by the instability of the area. the height of the bell's cross section is compensated by locally placing additional weights from the chain 19. The weights of the weights are adjusted so that the pressure under the bell when it is immersed in the barrier fluid during the entire stroke remains constant, i.e. so that the ratio — with a varying area F remains unchanged. Placing additional local loads in the installation on a chain with an even weight distribution along the length provides a more effective compensation for errors from pressure imperfections, simplifies the design of the installation, eliminates the primary source of error — the change in pressure under the bell, and hence the flow. The invention of the Bell-type volumetric-flow-metering installation for accurate reproduction and flow measurement, containing a bell placed in a liquid, a contact bar, a compensation circuit with a counterweight, a temperature-compensating device | and a pressure compensation device under the bell, so that, in order to improve the accuracy installation by compensating for changes in pressure under the bell, caused by deviations of the bell shape from a cylindrical shape, Made in the form of additional goods locally placed on the compensation chain, and the weight of the goods is selected in accordance with the condition of maintaining a constant ratio -% - with an unstable F, where G is the bell weight ,. F is the area of 9225 5 O "5 216 local section of the bell, and the distance between the loads is selected in accordance with the distance between the local deviations of the cross section of the bell. Sources of information taken into account in the examination 1. Pavlovsky A.N. Measurement of flow and quantity of gas and vapor liquids. M., 1967, p. 227-229. 2. USSR author's certificate (Г. Cl. G 01 F 25/00. 976 (prototype).