The Exhaust Steam Turbine.

Progress, Volume V, Issue 6, 1 April 1910, Page 195

The Exhaust Steam Turbine.

A paper of great suggestiveness, and likely to bo of the greatest use to engineers of the Dominion, pointing out not only the advantages, hut also tho limitations, of the exhaust-steam turbine, was read before the Manchester Association of Engineers in December last by Mr. J. N Bailey, who

remarked that the value of the exhaust steam wasted in Great Britain, since the introduction of the non-condensing engine for providing individual power, was in all probability equal to the National Debt. Iron and steel works used to be special offenders in this way, and the waste of exhaust steam in many of these works was only paralleled by the recklessness with which unprotected pipes were used for the conveyance of live steam. Collieries have been equally extravagant. The extravagance in the matter of exhaust steam has, it must be admitttd, been largely involuntary. It is only of recent years that satisfactory condensing winding-engines have been built, and it is probable that their adoption would have gradually become general had it not been for the production of the ex-haust-steam turbine. "Where the latter is installed as an adjunct to an existing set of non-condensing engines it can abstract nearly as much useful work from the exhaust steam as the reciprocator does from its supply of live steam. An important field for the exhaust steam turbine is also to be found where, although the engines fitted are relatively efficient and modern, an increase of power is required. Mr. Bailey gave a useful table, showing, for instance, that in the case of a triple-ex-pansion engine developing 1000 indicated horse-power for 131b. of steam per indicated horse-power per hour, an alteration of the valves and the addition of a turbine will raise the output to 1721 horse-power, and, at the same time, reduce the consumption to 10.35 ]b. per horse power. With a similar engine requiring 16 lb. per horce-power per hour the steam will be delivered to the turbine in a drier condition, and, consequently, Mr. Bailey states, the output will be increased to 1874 horse-power, and the consumption reduced to 11.21b. per indicated horse-power per hour. On the other hand, he points out that if no increase of power is required there will be no net gain on merely interposing an exhaust turbine between a reasonably efficient condensing engine and the condenser. ### # * The Trans-Andean Eailway, it is now computed, offers an Atlantic-Pacific steam service the shortest route between London and Sydney.