DE88824C - - Google Patents

Description

KA ₁ SERUCHHs Ä |

PATENT OFFICE.

The subject matter of the present invention is a working method and one for its practice invented machine, by means of whose atmospheric air or other gases are liquefied, essential for the purpose of separating gas mixtures, e.g. atmospheric air, perform.

The working process for atmospheric air, for example, is based on the well-known von the physicists observed the fact that oxygen, though its boiling point is higher lies as that of nitrogen, only liquefied together with part of the nitrogen can be that, on the other hand, from the liquefied and then brought to evaporation The mixture first separates the nitrogen, so that it becomes ever richer in oxygen, ever longer evaporation takes.

The liquefaction of atmospheric air has hitherto been carried out by physicists in such a way that that they are gradually liquefied and re-evaporated from ever more volatile ones Substances (such as carbonic acid, nitrogen oxide, ethylene, etc.) flowed one after the other.

In several patent specifications, first in English patent specification No. 2064/1857 by Dr. William Siemens, another method is described for this purpose, consisting in that compressed air, doing work in a cylinder, is supposed to expand, whereby you do that The equivalent of the work given externally is withdrawn, and that that is the result The temperature decrease achieved by means of a heat exchange device is continuously changed by the expanded to be transferred to the compressed air, so that the temperatures at The beginning and the end of the expansion decrease until liquefaction occurs.

However, this process has proven to be impracticable in practice and has not actually succeeded in liquefying the air. The reason for this is the impossibility of keeping an expansion cylinder in operation at temperatures below the critical temperature of the air (that is - 140 ^° C.) and of keeping the same with its engine sufficiently against heat absorption from outside protection.

Accordingly, several conditions cannot be met by the method described above fulfill, on which the achievement of the goal is absolutely dependent. On the other hand, it is under Using the newly invented method described below succeeded in achieving any To produce quantities of liquid air in continuous operation.

If you let a gas flow out under a certain pressure into a room in which If the pressure is lower, then, according to the laws of thermodynamics, the temperature is of the emitted gas, after it has come to rest again, the same - 'which before it was peculiar to the outflow as long as the gas fully complied with the laws of Mariotte and Gay-Lussac does not follow as long as the inner attractive forces of the smallest parts do not have a noticeable influence on the state of heat. But as soon as with a volume increase a consumption of latent heat is associated with overcoming these internal forces is, the gas is

Flow show a lower temperature than before. Well known to be for atmospheric Air does not strictly adhere to the aforementioned laws even in a normal state of heat correct, and in particular the well-known experiments by Thomson and Joule have shown that that a certain cooling actually takes place during the outflow, and indeed amounts to this cooling in degrees on the Celsius scale

if ρ ² - ρ ^{l is} the pressure difference in atmospheres and T is the absolute outlet temperature.

The more the specific volume of the air (by pressure and temperature reduction), the more significant is this cooling. This legal context is used in the present Machine made the following use:

In the drawing, C represents a compressor, by means of which the air is shifted from the pressure p ¹ to the higher pressure p- , whereby it heats up from the temperature t 'to the temperature t' ^1. As the Lull then passes through the cooling apparatus K , in which heat is withdrawn from it by cooling water or by some other available source of cold, its temperature drops from t ' ² to i ^{3 at constant pressure-2} .

^{In this state, the air is fed to a countercurrent apparatus G 1} that is as perfectly functioning as possible and protected as well as possible against heat absorption from the outside, and its temperature is further reduced (to t *) when passing through it (for the reason that will become immediately apparent). At the end of this counterflow ^{apparatus G 1} there is namely a regulating valve R ¹ through which the air flows out into the vessel V ¹ (also carefully protected against heat absorption), where the pressure p ¹ prevails.

After flowing out, the air will show a temperature i ⁵ , which is lower than £ ⁴ , the greater the pressure difference p- - p ¹ and the lower the temperature t * . With the temperature f ⁵ , the air in the countercurrent device G ¹ is now directed towards the incoming air and its temperature is thereby further reduced before it flows out, so that the two temperatures f ⁴ and f ^r> fall continuously until a supply of Warmth from outside or until a release of warmth inside establishes a state of equilibrium. The latter occurs as soon as the cooling has progressed to the point of condensation of atmospheric air, in that a liquefaction then begins, at which latent heat is released. After steady eingetretenem / .usland is a very specific and collect itself regulirender part of the outflowing air in a liquid state in the vessel, V ^1, while the remaining part returns through the countercurrent apparatus for Compressor C. The collected in the vessel, V ¹ liquid but passes through a second Regulirventil R "in the vessel, V-, in which atmospheric pressure prevails ^ ^0th When Druckreduclion of p ¹ i \ u (p" vaporizes a portion of the liquid, namely Part of the nitrogen. When the liquid in the vessel F-heat is then supplied by the fact that a more or less large part of the air brought by the compressor C to p ² flows through the spiral s , the evaporation of the nitrogen can be continued at will and then The remaining oxygen mixture (or the pure oxygen) can be drained through the tap /. The nitrogen escaping at / 1 exchanges ^{heat for the incoming compressed air in a countercurrent apparatus G 2.} If the oxygen is not as a liquid but as a gas is to be obtained, so lit one is the liquid through the countercurrent ^{apparatus G '' 1} flow counter to a third portion of the compressed air, with the evaporation and rewarming of the oxygen, the heat required is withdrawn from the compressed air. In this way, a complete recovery of the cold used to cool and liquefy the air is achieved and the machine only has to produce the cold necessary to cover the losses.

The feed pump P is used to fill the machine with gas and to replace the liquefied gas.

The power ratio of the present machine appears to be dependent in particular on the following conditions:

Because according to the above formula the cooling per atm. Pressure difference just Y is ₄ ⁰ C., then the Verflüssigungsprocefs only using very grofser pressure difference / ^'2 - p ¹ is possible. Experience has shown that to merely cover losses? ² - ^? ¹ greater than 20 atm. must be.

2. In order to keep the required compression work within moderate limits in spite of such large pressure differences, the pressure. ratio p ² - p ¹ should be chosen as small as possible. For example, if one sets ^ ² = 200 atm. and p ¹ = 100 atm., so to obtain a cooling of about 25 ⁰ C. in an effort which is not gröfser than when the air from one to two atmospheres. would be to compress.

3. The whole apparatus must, insofar as very low temperatures prevail in it, completely in a well insulating material

Claims (2)

can be enveloped without moving (engine) or immobile parts of it being exposed to atmospheric temperatures. The connections to the outside should therefore only take place at those points of the countercurrent apparatus in which atmospheric temperatures prevail. 4. Inside the apparatus, those parts which move under friction must not be exposed to the low temperatures necessary to liquefy the air, because the smallest additions, such as moisture, traces of lubricant, carbonic acid, etc., are present at these temperatures freeze and prevent movement. 5. The countercurrent apparatus must represent ducts with metallic walls of a very considerable extent, which may only be connected to one another with metal at their ends and throughout their entire length in the most perfect way against heat emission from their individual parts among one another, as well as against heat absorption from outside must be protected. The Siemens process described at the outset behaves as follows under these conditions: Regarding 1 and 2. The pressure ratios are fundamentally different, since in the Siemens process low pressures (between 1 and 4 atm.) Are sufficient and only considered , while in the present method at least 20 atm. are required. The conditions to 3 and 4 apply jointly to the Siemens and the present procedure, but cannot be fulfilled in practice with the Siemens procedure. All heat exchange devices which have been described so far in connection with the Si em ens's process do not meet the conditions set out under 5. In the present machine, the latter is achieved in that, as Fig. 1 indicates, these apparatuses are formed from two tubes each of great length (e.g. 100 m) which, plugged into one another, are rolled up and rolled up in a spiral shape wooden spiral supports are mounted, and that the turns are insulated so far from each other and towards the outside by an excellent insulating material (e.g. raw sheep's wool). as can be seen from the current state of the art. There is no need for special proof that the present machine is also used to liquefy gases other than atmospheric air. can be used to separate other gas mixtures by way of liquefaction. Furthermore, it is evident that the low temperatures t "achieved in the vessel V1 are also used for purposes other than the liquefaction of gases, i.e. that the existing machine can generally be used as a refrigeration machine for extremely low temperatures. Ρλ τ ε ν τ - A ν s ρ κ C c η ε: 1. The liquefaction of atmospheric air or of another gas by compressing the gas, then first for delivery the heat of compression through a cooler and then through an astronizer and allows it to flow out at a considerably lower pressure, and then that • The temperature decrease resulting only from the performance of "internal work" transferred in the countercurrent apparatus to the flowing compressed gas and this cycle is initially repeated continuously with the same amount of air, so that one progressive decrease in temperature takes place in front of and behind the exhaust mouth, until liquefaction occurs. 2. To carry out the method identified under 1., a machine consisting of a gas feed pump P, a compressor C, a cooler K, a countercurrent ^{device G 1} , a regulating valve R ¹ and a collecting vessel V ¹ , which gcmäfs the operation characterized in claim 1 are connected with each other and the latter three apparatuses are completely enveloped by the most effective dielectrics of heat. 3. The addition of a second vessel V ' ² with spirals s and a second countercurrent ^{apparatus G 2} to the apparatus marked under 2. for the recovery of the cold which is expended when using this apparatus to obtain oxygen from liquid air for the liquefaction of the evolving nitrogen became. 4. The addition of a third countercurrent device G ³ to the _{devices identified under #} 2 and 3 for the purpose of recovering the cold which was expended on the liquefaction of the oxygen, in the event that it does not have to leave the machine in a liquid state, , but can be used as a gas. 1 sheet of drawings.