SU5303A1 - Instrument for measuring the weight quantities of a flowing gas, vapor or liquid using a differential fluid manometer - Google Patents

Description

The basis of the proposed instrument is the principle of a venturi nozzle, in which a pressure difference is observed in the compression chamber and in the expansion chamber, if these parts are connected with a narrow tube with mercury. The pressure in the knee adjacent to the compression chamber is greater than the pressure in the knee connected to the expansion chamber, and the pressure difference is quite closely proportional to the weight of the passing liquid, steam or gas. This pressure difference is measured by an electric meter.

In FIG. 1 is a curve plotted using the formula Q Fxy2ghYZ; FIG. 2 is a vertical section of the device and FIG. 3-cut it with the indication of the circuit of the electric circuit.

In the above formula, on the basis of which the curve is plotted (Fig. 1), Q denotes the weight of the gas or liquid to be measured, F is the cross-sectional area of the throttle valve, x-coefficient depending on friction and design, 1/2 4, 43, Z-specific gravity of a gas or liquid, A - pressure difference on both sides of the throttle valve. To construct the curve, 10 different pressure differences are plotted on the ordinate, each time starting from 0. Through the thus obtained ends of the ordinates, lines parallel to the x-axis are drawn. Having then set aside, beginning from O, successively, equal parts so that their starting and ending points fall on the above mentioned

parallels, get by connecting individual points a curve, each point of which corresponds to a certain value Q of the above formula. According to this curve, the measuring tube b is bent and used in the proposed device, with mercury enclosed in its lower knee and an electrically conductive high-resistance liquid being placed on top of the latter, into an electrical circuit of an alternating current meter. The meter measures the resistance as a function of the pressure change of the measured gases or fluid passing through the throttle flange, and notes on the tube b scale the weight quantity of fluid flowing through the pipeline, vapor or gas.

In the embodiment of the device shown in FIG. 2 and 3, the bent tube b is placed at one end into an electrically insulated vessel a located in front of the throttle flange, and the other end enters the vessel c attached to the pipeline behind the throttle flange. Vessel a and lower knee of tube b are filled with mercury. The tube b is bent in such a way that when the pressure is balanced, mercury reaches point o. The vessel with consists of two otdetyy / and e. Over the mercury in the vessel and pour insulating liquid with a specific gravity, the average between the specific weights of mercury and water.

As much mercury is poured into the bottom of the vessel as needed to isolate the separation from the separation. The free space in the curved tube b and the compartment e are filled with a medium that conducts electric current, but has great resistance. The compartment / and the free space in the vessel a are filled up to the throttle flange when measuring quantities of steam or water with water, and when measuring quantities of gas with a corresponding gas. With

the flow of gas, vapor or liquid through the throttle flange included in the pipe, the movement of the mercury meniscus in a bent tube is in a linear relationship with the measured amount of gas or liquid. Each change in the position of the mercury column in the curved tube is accompanied by a change in the length and, consequently, the resistance of the conductive column of fluid in the tube b. The change in resistance of the mercury column itself can be neglected, since it is very small. The resistance changes are transmitted to the meter connected to the device and the source of electricity, as shown in FIG. 3. The device requires the use of alternating current, in order to avoid polarization, and constant voltage.

The subject of the patent.

Claims (2)

1. An instrument for measuring the weight quantities of a flowing gas, vapor or liquid using a differential liquid manometer using a throttle valve, characterized by using a curved, according to the formula Q Fx (according to the diagram of Fig. 1), a measuring tube b containing mercury in the lower knee and filled electrically conductive fluid with a large resistance liquid, introduced with mercury into the electrical circuit of a constant-voltage AC meter, measuring resistance versus pressure change measured gases or liquids passing through the throttle flange, and marking on the graduated scale of the tube the weight quantity of fluid flowing through the pipeline, steam or gases (Fig. 1, 2, 3). 2. The form of the instrument according to claim 1, characterized in that it consists of two vessels a and c, connected one before the throttle flange, the other behind it to the pipeline of the medium being measured (Fig. 2), and between them - connected by a curved tube b (Fig. 1-3), in which vessels the end of tube B, from the electrically insulated vessel a, is immersed in a layer of mercury, in a vessel with, divided by mercury and a septum into two compartments / and e, tube b protrudes above the level of mercury in compartment e, filled with a high resistance electric medium (Fig. 3). FIG. 2 / X  ch (}