RU1772509C - Method of removing gases and vapors from heat insulating cavities of cryogenic pipe line - Google Patents

Abstract

SUMMARY OF THE INVENTION: the adsorbent is regenerated by heating with heating steam supplied to a coil located in the adsorbent layer. Desorbed vapors and gases are pumped out of the insulating cavity. Simultaneously with the heating of the adsorbent, a stream of dried gas is supplied to the heat-insulating cavity at one end of the pipeline. Gas is evacuated at the opposite end of the pipeline. The presence of water vapor in the gas evacuated from the cavity is monitored and, after disappearance, their gas supply is stopped. The evacuated gas is drained and again fed into the cavity. The evacuated gas is supplied to the coil. The gas exiting the coil is fed into the cavity. During heating of the adsorbent and feeding into the gas cavity, the pressure in it is maintained at a level of 200-400 mm Hg. 3 C.p. f-ly, 3 ill.

Description

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The invention relates to the field of cryogenic technology, and in particular to methods for removing gases and vapors from the insulating cavities of cryogenic products

A known method of removing gases and vapors from the heat-insulating cavity of a cryogenic pipeline is to regenerate the adsorbent by heating it with heating gas supplied to a coil located in the adsorbent layer and pumping desorbed vapors and gases from the heat-insulating cavity 1.

The known method has a significant drawback - high energy costs associated with the duration of the adsorbent regeneration process and the inability to efficiently dry the heat insulation located in the heat-insulating cavity.

The aim of the invention is to reduce energy consumption by reducing the duration of the process of regeneration of the adsorbent and the intensification of the drying process of multilayer thermal insulation.

In FIG. 1, 2 and 3 are diagrams of various embodiments of the described method.

A system for implementing a method for removing gases and vapors from a heat-insulating cavity of a cryogenic pipeline in the form of a casing 1 and an inner pipe 2, forming a heat-insulating cavity 3, in which a multilayer heat-insulating 4 and adsorbent 5 located on the inner pipe 2 are located, contains a coil 6, installed in the adsorbent layer 5, and a purge gas supply system including inlet and outlet valves 7 and 8,

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connected to the heat-insulating cavity 3, a vacuum compressor 9, purge gas dehumidifiers 10 and 11, filled with, for example, silica gel, a gas heater 12 and a moisture meter 13.

The method is implemented as follows.

Heating gas is supplied to the coil 6, the temperature of the adsorbent 5 rises, and the gases and vapors absorbed by it begin to be desorbed. At the same time, purge gas is supplied to the cavity 3 through the desiccant 10. The purge gas stream captures the stripping gases and vapors and carries them to the desiccant 11. At the same time, the entrainment process from the heat-insulating cavity 3 of 4 gases and vapors, mainly water vapor, released from the surface of the multilayer heat insulation is intensified. .

For greater efficiency, the gas is supplied in a closed circuit, and when it is supplied through the coil 6 and heater 12, in addition to heating the adsorbent 5, heating of the multilayer thermal insulation 4 is also achieved, which additionally intensifies the desorption of water vapor from its surface and also allows more efficient use of the heat content heating gas without discharging it into the atmosphere with a sufficiently high temperature.

The most optimal conditions for carrying out the process associated with drying the thermal insulation 4 is to carry out it while maintaining the pressure in the thermal insulation cavity 3 at a level of 200-400 mm Hg. In this case, the smallest resistance to the flow of the purge gas through the heat-insulating cavity is achieved, its effective capture of molecules of emitted vapors and gases, as well as intense heat transfer both in the heat-insulating cavity directly and in the adsorbent layer, which contributes to the rapid and uniform heating of the entire adsorbent 5 .

FORMULA AND SECTION

Claims (4)

1. The method of removing gases and vapors from the heat-insulating cavity of the cryogenic pipeline, which consists in the regeneration of the adsorbent by heating it with heating gas supplied to located in the layer adsorient coil, and pumping desorbed vapors and gases from thermal insulation cavity, characterized in that, with In order to reduce energy costs by maintaining the duration of the adsorbent regeneration process and by intensifying the process of drying multilayer heat insulation, a flow of dried gas is supplied to the heat-insulating cavity at one end of the pipeline, and its pumping is carried out at the opposite end of the pipeline, the presence of water vapor is controlled in the gas evacuated from the insulating cavity and after disappearance, their gas supply is stopped. 2. The method according to claim 1, characterized in that the heat pumped from the thermal insulation is ... gas cavity is drained and again fed into the insulating cavity. 3. The method of pop. 1. characterized in that the gas evacuated from the insulating cavity is drained, heated and fed to the coil, and the gas exiting the coil is fed into the insulating cavity. 4. The method according to claim 1, characterized in that in the process of heating the adsorbent and feeding gas into the heat-insulating cavity the pressure in the latter is maintained at a level of 200-400 mm Hg. 35 L g gV. 356  L i i Fkg 2 FIG. 3