SU757919A1 - Device for measuring pressure and density of saturated liquid vapours - Google Patents

Description

The invention relates to devices for measuring physical quantities and can be used in determining losses, quality and explosive situations as a result of evaporation of petroleum products during their storage and transportation.

A device is known that includes graduated burettes placed in a thermostat and communicating with each other through a test tube with the medium under study and shut-off valves [Ϊ].

The method of bubbling liquid with air bubbles used in the known device, manual adjustment of bubbling, removing the tube with the test medium from the thermoplastic, negatively indicates the accuracy, reproduction of the measurement results and the complexity of the experiments.

A device is known that includes an evaporator placed in a thermostatting housing with a liquid under test, which is connected by means of connecting tubes with measured burettes, a leveling vessel and a weighing device: £ 2.}.

The drawbacks of the device are low accuracy and reproducibility of measurement, increased labor intensity and duration of experiments due to the need to remove the evaporator from the thermostat to the outside for weighing the manual adjustment of the jet pressure using a leveling vessel.

The purpose of the invention is to improve the measurement accuracy by eliminating the loss of vapors of easily volatile liquids.

This goal is achieved by the fact that the device is equipped with valves, made of two parts, the upper one. Which are installed on the connecting tubes, and the bottom - on the evaporator, mounted on the weighing device and installed to move in a vertical plane,

The drawing schematically shows

the proposed device.

h 7579

The device contains / thermostatically controlled Case 1, an evaporator 2 with a test liquid, such as benzoin, detachable valves, the lower parts 3 and 4 of which are installed on the evaporator, and the upper 5 and 6 are installed on connecting pipes and three-way valves 7 and 8 communicate with the measuring burettes 9 and 10 and water pressure gauges 11 and 12, leveling vessels 13 and 14, p. driven by guides 15 and 16, Lifting device 17, weighing device 18 connected with thrust 19 passing through hermetic shutter -20, with evaporator 2, grips 55 of three-way valves 21 and 22, thermometer 23 thermal sensor 24 fan 25, thermoelement 26 , thermostat 27, remote control 28 controls.

Each of the valves consists of two 20 parts: the bottom 3 and 4, the top 5 and 6. Each part has an open hole at one end, and the other is hermetically sealed due to the presence of a spring device and petrol-resistant washers. 25 The lower parts with their open ends are mounted on the evaporator 2. The upper parts 5 and 6 are rigidly fixed on the connecting tubes and communicate with their open ends with the burettes 30 9 and Y. When docked, the lifting device 17, lifting the evaporator 2 s / lower parts of valves 3 and 4, brings together both parts of the valves, facing each other closed holes. 35 Upon contact, the closed holes are first isolated from the external environment. At the end of the docking, when the protrusions of the valves, having met, squeeze out the springs, the holes that were closed 40 before that in both parts, open and provide a message. between the capacity of the evaporator and burettes 9 and 10 and, therefore, the possibility. blowing air from one burette to another over 45

test liquid in the evaporator.

The lower parts 3 and 4 valves are attached on. the diameter of the evaporator 2, with its outer side perpendicular to the side surface of the brazed metallic round rods ₅₀ Kie. In the lower part, they are soldered at the level of the bottom of the evaporator and take the pressure when docked. In the upper part, the rods have cavities with lateral holes with which they fit 55 'with the side holes of the evaporator. Outside in the upper part, the rods are threaded, on which they screw up 'with their open ends

19 4

lower parts of valves 3 and 4 thanks to

what are they through the internal cavity and]

side holes of the rods are communicated

with vaporizer.

The device works as follows.

Before the start of the experiment, a certain amount of clean air is sucked in with the equalizer of the vessel 14 in the burette 10) while in the burette 9 air is pushed out. The device closes, automatic temperature control is turned on and does not open until the end of the experiment. When the set temperature is reached, the temperature is equalized by pressure in the system with atmospheric, for which the evaporator 2 is lifted by lifting device 17, the lower parts of valves 3 and 4 are joined with the upper 5 and 6, after which the message of the evaporator and the burettes with atmosphere is blocked by three-way cranes 7 and 8 using grippers 21 and 22. Lowering the lifting device 17, with the shutter 20 open, weigh the evaporator with the test liquid prior to the experiment.

After a new docking valve, the device is ready for the experience. When lifting leveling. body 14. and lowering the vessel 13, the air from the burette 10, passing over the surface of the test liquid, is saturated with its vapor. At the same time, the pressure in the atmospheric system is equal by adjusting the speed of the leveling vessels and is monitored by gauges 11 and 12. Then, the air is driven through the leveling vessels in the opposite direction and this is repeated until the full saturation of the air with the vapor of the tested oil product occurs, which is fixed by stopping the increment of the vapor-air mixture in burettes 9 and 10.

Lowering the lifting device 17 and opening the shutter 20, the evaporator is weighed after the experiment, the weight of the evaporated liquid is determined from the difference in weights. After fixing the final volume of the vapor-air mixture by dividing the burette 10, it is thrown out and the instrument is prepared for the experiment with the remaining liquid.

In each experiment, the saturated vapor pressure is determined by the formula

five

where P) l is the atmospheric pressure during the experiment, is the pressure of the saturated

water vapor at a temperature of experience

V ,, - the volume of portions of clean air

to saturation, - final volume

steam-air mixture.

The density of saturated steam of the test oil in each experiment determined 'η ^Dgp

divided by the formula, t ~ -yr "

^{5 ν} η ·%

where LH is the loss of mass of liquid from the evaporator in this experiment.

According to these values, build graphs of the dependence of P ₅ - £ (cG) _; RD = £ (^), where GdesG-13 is the value of the weight loss of the test product from the initial one.

Claims (1)

Formula fig e m e n s A device for measuring the pressure and density of the saturated liquid vapor included ²⁰ aspirants, placed in a thermostated enclosure evaporator investigated 757919 6 fluid, communicating by means of connecting tubes with measuring burettes, leveling vessel and weighing device, characterized in ₅ in that with a chain of improved measurement accuracy by eliminating the loss of vapors of volatile liquids, it is equipped with valves made of two> parts, the upper ones of which are installed 40 on connecting pipes, and on the bottom of the evaporator, mounted on a weighing device and installed with the ability to move in a vertical plane.