S/A WILLIAM SIEMENS, F.R.S. 



ON A NEW REGENERATIVE CONDENSER FOR HIGH- 

 PRESSURE AND LOW-PRESSURE STEAM-ENGINES. 

 BY MR. C. WILLIAM SIEMENS.* 



THE condenser of a steam engine has for its object the complete 

 discharge of steam from within the working cylinder after it has 

 served to propel the piston. This is effected by conducting the 

 expended steam into a closed chamber, containing an extended' 

 surface of comparatively cool substance, which absorbs the latent 

 heat of the steam and thereby reduces it to its liquid state. Cold 

 water is generally employed for this purpose, which is either 

 brought into immediate contact with the steam, as is the case in 

 Watt's injection condenser ; or through the medium of metallic 

 walls, as in the surface condenser by Hornblower, improved upon 

 by Hall and others. The more or less perfect condensation of the 

 steam depends, first, on the absence of air from the condenser, and 

 secondly, on the temperature at which condensation takes place. 



The accompanying table shows the elastic force of steam in 



TABLE OP THE PRESSURE OP THE VAPOUR OP WATER, PROM THE 

 FREEZING TO THK BOILING POINT. 



vapour, at various temperatures. It will be observed that, in 

 order to produce a perfect vacuum, the water should leave the 

 condenser at about 32 Fahr., or be introduced in the form of ice. 



* Excerpt Minutes of Proceedings of the Institution of Mechanical Engineers, 

 1851, pp. 1834. 



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