DE7222558U - Collection container for storing sulfur hexafluoride in liquid form - Google Patents

Description

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Aktiengesellschaft Brown, Boveri & Cie., Baden (Switzerland)

Collecting container for storing sulfur hexafluoride in liquid form

The invention relates to a collecting container for storage of sulfur hexafluoride in liquid form, in particular for a gas supply device for the maintenance of SFg gas-filled electrical equipment and switchgear, using devices for extracting air and moisture.

In electrical devices and switchgear, it is common practice to encapsulate them and encapsulate them with sulfur hexafluoride gas to fill, as the latter has favorable electrical properties, e.g. high insulating properties. Because of the comparatively high price of SFg will be the gas during the

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Maintenance sites taken from the devices or »switchgear, in so-called service stations and saved for later Recycled, whereby primarily a cleaning and dehumidification of the gas is carried out.

The invention is based on the object of providing a simple and inexpensive solution for a collecting container for liquid sulfur hexafluoride specify, which enables a separation of the water and gas residues from the liquid SFg in the collecting container is leaving pure SF ^ liquid for reuse can be removed from the collecting container.

According to the invention, this can be achieved in that the Vent line of the venting device into the top of the collecting container opens and the dehumidifying device is designed as a cylindrical filter candle, which is located in the collecting container extends approximately over its total clearance height.

The drawing shows an embodiment of the invention. Flg. Fig. 1 shows an elevation section of the receptacle and

2a to 2d show four characteristic in a schematic representation State phases in the collecting container depending on the pressure.

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In Fig. 1, the pressure-tight collecting container 1 is tightly closed with a sham cover 2 at the top. The feed line 3, which is provided with a shut-off valve 4 and by means of which the liquid SFg to be stored is fed to the collecting container, is passed through the cover 2. In a manner known per se, the gaseous SFg, which is sucked out of the encapsulation of the devices or switchgear, is liquefied by compressing and cooling before it reaches the collecting container. The removal line 5, which can be closed by the shut-off valve β, is used to remove stored, liquid SFg from the collecting container 1. The line 5 dips considerably further into the collecting container than the line 3. Furthermore, the vent line 7, which can be shut off by the vent valve 8, is inserted in the cover 2. A pressure gauge is designated by 9 and a safety valve is designated by 10. Another lockable line 11 leads at the bottom into the collecting container 1. Via the line 11, the collecting container can be connected, for example, to storage bottles that can store or dispense liquid SFg. Finally, the filter candle 13 is attached to the cover 2, which extends in the collecting container 1 practically over its entire clear height. The filter candle 1 $ serves as a dehumidifying device and for this purpose contains molecular sieves and activated alumina (Al ₀ O,) in a perforated, stable casing. The molecular sieves are commercially available and have spherical ones

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or rod-like structure, so that they are next to the clay'e'rde can be easily filled into the perforated shell of the filter candle 13. At the lowest point of the collecting container 1, a drainage valve 12 ί can be attached, which is designed as a needle valve, for example.

In the simplest case, the vent valve 8 can be a manual valve that is actuated by the operator in the desired pressure. However, the vent should only be actuated if there are pressures in the collecting container 1 at which the SF / - is only present in the liquid phase above a pressure critical for SFg (38.33 ata). It can therefore be useful to provide means, independently of the operator, which only allow actuation when the pressure is high enough. In the simplest case the manometer 9 is provided to contact with a corresponding \, which then in the BetätigungSicreis as

■ solenoid valve designed vent valve 8 is arranged, J-

■ the contact works in such a way that ep if the pressure is too low

is open. The collecting container can also contain a liquid

own fitness level indicator. The mode of operation is explained in more detail below with reference to FIGS. 2a to 2d. As long as there is subcritical pressure (p <CP ₁ ^) in the collecting container 1, there is ² I above the SFg gas and water vapor in space I 2. At the bottom, water collects in liquid form, since its specific weight is now greater than that of the SFg liquid (FIG. 2a). Achieved or exceeded as a result of additional funding

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of liquid SF, - the pressure in the collecting container reaches the critical value (P = P _k )> the entire SFg portion of the gas phase in space 14 precipitates as a liquid (Fig. 2b). Now there is only a mixture of air and water vapor in room 14. Depending on the filling level of the collecting container, the subsequently conveyed SFg has a temperature at which the water particles that may have turned into ice at the beginning of the filling are liquefied and z * T * evaporated so that adsorption by the filter candle (molecular sieve) can take place As the pressure increases, the specific gravity of the SF ^ liquid exceeds that of the water. As a result, the water initially located at the bottom of the collecting container rises to the top (FIG. 2c) and gradually comes into contact with the surface of the pilter candle over its entire length. After a certain time, during which a pressure of, for example, 50 ata prevails in the collecting container, the situation shown in FIG. 2d arises, in which SF liquid is now at the bottom, a layer of water above and a mixture of air and water vapor at the top. The latter can now be released into the open. In addition, in the pressure range above the critical pressure (P _kr ), pure SFg liquid can be removed from the collecting container without the risk of water carrying the kit.

Claims (1)

- ö - · 'τθ / 72 D ίη sayings 1, collecting container for storing sulfur hexafluoride in liquid form, especially for a gas supply device for the maintenance of SF, gas-filled electrical devices and Switchgear, using devices for air and dehumidification, characterized in that the vent line (T) of the ventilation device (7> 8) above in the collecting container (1) opens out and a dehumidifying device is designed as a cylindrical filter candle (13), which is in the collecting container (1) approximately over its entire clearance Height extends. • i 2, collecting container according to claim 1, characterized in that that means (8, 9) are provided which enable the venting device to be actuated (7> 8) only for pressure values in the collecting container (1) allow those above the critical for SPg Pressure at which the SF ^ only in the liquid phase is available. '' 3 «collecting container according to claim 1, characterized in that that the filter candle (I5) molecular sieves and activated clay contains. Public Company _ Brown, Boveri & CIt-.