SU382944A1 - DEVICE FOR THE SELECTION OF THE PRESSURE OF VAPORS OF COOLING AND CRYSTALLIZING LIQUIDS - Google Patents

Description

one

The invention relates to the field of instrumentation, in particular to protective devices for differential pressure gauges.

Protection of the differential pressure gauge using continuous blowdown is accomplished by installing blow-down tubes that are inserted into the measuring cavity of the process line. However, when measuring the vapor pressure of solidifying and crystallizing liquids, it is not excluded that condensing and solidifying substances enter the measuring system.

The purpose of the invention is to prevent clogging and clogging of tubes and gauges. This is achieved by the fact that in the device for selecting the pressure of the vapors of solidifying and crystallizing liquids, the purge tube is placed in a closed case equipped with an inlet, with the glass facing the open bottom down inside the case, and the purge tube is placed inside the cup. This inlet is made in the housing above the lower edge of the glass. The purge tube can be attached to the upper bottom of the body using a bellows placed inside the glass, with the possibility of moving the tube along the axis.

FIG. 1 shows a common device.

view; in fig. 2 shows an embodiment of the device using a bellows.

The device contains a purge tube 1, a housing 2 with an inlet 3 and a cup 4. The tube / can be fixed to the upper bottom 5 of the housing 2 (as shown in Fig. 1) and movably with the help of a bellows 6 (see Fig. 2). The inlet 3 is made in the housing above the lower slice of the glass 4.

The device works as follows.

The device is installed in the line of the technological system.

The vapors of the substance whose pressure is measured penetrate into the housing 2 through the inlet 3, condense and create a layer of hot condensate, the level of which depends on the height of the lower edge of the opening 3. The heat exchange between the vapor and condensate maintains the temperature of the condensate above the solidification point. Excess condensate flows back into the process line. Through a known control device, which can be, in particular, a control cup, an inert gas is fed into the measuring system, which is then blown through the sampling device. The gas enters the sampling device through a tube L It fills the internal cavity of the glass 4 and from under its lower cut, passes through a layer of hot condensate, enters the external cavity 7 of the device bounded by the housing 2 and the glass 4, and through the opening 3 leaves technological line. The pressure of the inert gas in the measuring system, in the tube / and inside the glass 4 is equal to the pressure in the process line. The resistance of the condensate column through which gas is bubbling can be taken into account, if necessary. When the pressure in the process line decreases, the pressure inside the measuring system will also decrease, since the gas from it through tube 1, cup 4, through the condensate layer and hole 3 will flow freely into the process line.

Consider the operation of the device with increasing pressure in the process line. The pressure difference between the pressure in the outer cavity 7 of the device and the pressure in the inner cavity of the glass 4 and in the tube / first increase. The vapor of the measured water supply exerts pressure on the surface of the condensate in the cavity 7 of the device, squeezing the condensate into the internal cavity of the glass 4 and very slightly into the tube 1. A purged inert gas continuously passes through the tube 1, because it has great resistance to penetrate the measured medium . Along with this, the inner cavity of the cup 4 acts as a buffer tank. With increasing pressure of the measured medium, this capacitance partially smoothes, dampens the pressure pulse, providing a damping effect. The inert gas, which is in the cavity of the cup 4, is somewhat compressed and, increasing its pressure, prevents the condensate level from rising further, inside the cup. The large tube resistance / with respect to the measured medium in combination with the damping effect of the inner cavity of the glass 4 and removal of the tube from the surface of the rising condensate prevents the hardening substance from entering the measuring system.

Even in the case of a sharp increase in the measured pressure, the bunks of the measured substance will not be able to penetrate further than the cavity of the glass 4, since the tube 1 with a sharp rise in condensate will be blocked by its small pillar. The condensate from the tube 1 will be quickly removed, the pairs 4 condensed into the cavity of the cup will condense, and the condensate will be removed from the inert gas by increasing pressure

the inner cavity of the cup 4 until equilibrium is restored in both systems. Using such a sampling device, the measuring system, filled with an inert gas, is permanently separated from the production line by a moving layer of hot condensate of the medium being measured, which in the selective device creates a clearly defined interface between the two systems and protects the measuring system from a possible hardening substance. In the case of using a sampling device, made in the version with bellows (see Fig. 2), its operation is similar to that described

above, except that the purge tube 1 can move along the axis under the action of a pressure difference. For example, when inert gas is supplied through a tube / under the action of its pressure, the bellows 6 is compressed,

and its bottom, together with tube 1, moves upwards somewhat. When the process pressure B decreases, the bellows 6 under the action of elastic deformation will tend to return to its original position, and its bottom

with tube 1 moves down.

With increasing pressure in the process line, the pressure in the internal cavity 4 also increases and the bellows 6, squeezing, moves the tube / upwards, withdrawing it from

condensate surfaces.

Subject invention

Claims (2)

1. A device for sampling the vapor pressures of solidifying and crystallizing liquids, comprising a purge tube inserted into a measuring cavity, characterized in that, in order to prevent clogging and clogging of the tube and meter, the purge tube is placed in a closed housing equipped with an inlet, moreover, inside the case, a glass is attached to its upper bottom, the open end facing down, and the purge tube is placed inside the glass, while the inlet is made in the body above the bottom with cut glass 2. The device according to claim 1, characterized in that in it the purge tube is attached to the upper bottom of the body with the help of a bellows placed inside the glass, with the possibility of moving the tube along the axis. Fig /