Untitled record

Process for cleaning and filling liquefied gases <p><p><tgroup cols="1"><tbody><row><entry align="right">1) The technically liquefied gases contain</entry></row><row><entry align="right">moderately more or less small amounts of</entry></row><row><entry align="right">Foreign substances, which are some of the uses</entry></row><row><entry align="right">purposes are disturbing. In particular, this applies to</entry></row><row><entry align="right">Water, which is common in liquefied gases, mostly</entry></row><row><entry align="right">partly in gelfistem condition, is included.</entry></row><row><entry align="right">For example, technical coal</entry></row><row><entry align="right">dioxyd, which flows from the vapor space of the pressure</entry></row><row><entry align="right">container, usually some</entry></row><row><entry align="right">Hundredths of weight of water; from the bottom</entry></row><row><entry align="right">Part of the pressure vessel removed liquid</entry></row><row><entry align="right">Kolilendiolv (1 often has a considerable amount</entry></row><row><entry align="right">higher water content.</entry></row><row><entry align="right">(l) the wealth of contaminating foreign</entry></row><row><entry align="right">Of gases is usually in the</entry></row></tbody></tgroup></p></p> @@ 'else. that the gas by suitable filters, for. B. activated carbon filter or filter with active silica, is passed. If the purified gas is to be used in a relaxed state, cleaning usually does not present any difficulties. However, for those purposes in which the gas in the liquefied state must be filled in compressed gas cylinders, the cleaning and filling process is difficult, depending on the thermal properties of the gas.

The basically closest way to cleaning and bottling would be a distillation of the liquefied gas in such a way that it evaporates under heat, filtered in the vapor state and then re-compressed by cooling. However, such distillation is cumbersome on an industrial scale and can only be carried out with a relatively high expenditure of energy. Carbon dioxide would have to be heated to a temperature of about 10 ° C and, after passing through the purifying filters, cooled to about -15 ° C to effect evaporation and re-liquefaction. The cooling necessary to achieve this temperature gradient can only be achieved by means of cold mixes or refrigerating machines; This also makes the process costly in practical, continuous operation.

The object of the invention is to simplify the purification of liquefied gases and their simplification and to carry it out with less effort. The essence of the invention is that &lt;las zti purifying gas is brought before evaporation and filtering to a pressure which is high enough to allow liquefaction of the vapor at a temperature which is to be maintained without the use of refrigerants, such as at the temperature of tap water. This provides the advantage that the freezing is eliminated and is replaced by the practically no maintenance requiring and considerably cheaper: Wasseckü'hlung.

In the drawing, an apparatus for carrying out the method according to the invention is shown schematically.

The liquefied gas stored in the pressurized gas container i passes through a pump 2 into the evaporator 3, in which it is completely evaporated with the supply of heat. Then it passes through (read with the corresponding filter mass charged pressure vessel d, from which it is passed through the fed with tap water cooler 5 in a liquid separator 6 and from this into the pressure vessel to be filled.

The filtering takes place in the vapor state. In order to achieve the liquefaction in the condenser 5 at the usual tap water temperature, for example 1o to i2 ° C, the pressure in the system is increased by the pump 2 to the level required for this purpose. In the case of liquefied carbon dioxide, which at -15 ° C has a pressure of 32 atm. As has been found by experiments, this is an increase in pressure to about 8o atm. necessary, which can be effected by a transfer pump of relatively small power and of conventional design.

The pump 2 need not be constantly in action during the periodic filling process, but only as long as is necessary to accumulate a certain, sufficient for one or some filling operations supply of liquefied gas in your liquid separator 6. It can also be operated periodically and automatically controlled by the pressure prevailing in the system, claß always the required pressure level is maintained.

In this case, the further advantage is achieved that an excess of the maximum allowable pressure in the system riding safety is avoided.

With periodic removal of gas as in the filling of individual pressure bottles, it may be disadvantageous that the vapor flow through the filter 4 does not pass continuously, but that after each withdrawal, a standstill occurs in the system. To alleviate this problem, according to another invention, the steam after passing through the filter 4 and before entering the liquid separator 6, is throttled so that, regardless of the timing of the individual filling operations, an approximately constant vapor flow through the filter. 4 goes through.

For this purpose, between filter .I and cooler 5, a throttle body; be arranged.