This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 Excerpt: ... steam engine. In practice the workman in charge of running these machines has, so to say, only to look after the expander. Multiple expansion.--In this way the essential condition for the production of cold by expansion with external work is, that the expansion be wholly accomplished under suitable temperature ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 Excerpt: ... steam engine. In practice the workman in charge of running these machines has, so to say, only to look after the expander. Multiple expansion.--In this way the essential condition for the production of cold by expansion with external work is, that the expansion be wholly accomplished under suitable temperature conditions, that is, at the highest temperature compatible with the carrying out of liquefaction. We have seen that this is not the case, far from it, when matters are so arranged that liquefaction takes place spontaneously and completely, at the end of expansion; but that if liquefaction is effected under pressure, the commencement of expansion is improved, and that we obtain, through compound liquefaction, an immediate improvement in the expansion itself, thanks to the heating of the air before the end of its expansion. It will be understood that nothing would prevent a further advance in this direction and a further improvement in the conditions, save the increasing complication of the parts, insufficiently compensated for by an ever-diminishing advantage owing to further fractionating the expansion, that is, through effecting it in three or four successive stages, each of them followed by liquefaction. We arrive thus sensibly, in the limit, as we shall see presently, at an adiabatic expansion from--100 C to--140 C, and thereafter at an isothermic expansion down to the end of the operation. Other remedies.--Another means of utilising liquefaction under pressure may be used to avoid the defective state of matters which characterise the close of expansion, that is, not to expand to the very end. It will lie sufficient for this object to operate in the same way as Linde by collecting the partially expanded air when issuing from the exchanger and reco...
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