1862 London Exhibition: Catalogue: Class VIII.: Walter May and Co
From Graces Guide
1927. MAY, WALTER, and CO., Suffolk Works, Berkeley Street, Broad Street, Birmingham.
Double-cylinder steam engine and surface condenser; portable corn mill.
This engine is designed especially with a view to obtain uniform rotative power, and at the same time to carry the expansion of the steam to a great extent, for the purpose of ensuring the utmost amount of economy in fuel.
The cylinders are respectively 10 and 21 in. diameter, and the length of stroke is 2 ft. in each case; one external steam jacket, fed direct from the boiler, embraces both cylinders. The steam enters the small cylinder at the full pressure of the boiler, and when the piston has travelled half its stroke, is cut off and expanded through the remainder of the stroke. It is then exhausted into the wrought-iron reservoir, shown by dotted lines under the bedplate, this reservoir being jacketed with high-pressure steam from the boiler. Here the steam is stored up until the crank of the larger cylinder, which is at right-angles to that of the smaller one, has brought its piston to the end of the stroke, when the slide valve of the large cylinder opens and admits the steam from the above mentioned reservoir, and, as in the smaller cylinder, it is again cut off at half stroke, expanded through the remainder of the stroke, and exhausted into the condenser, which may either be a surface condenser, as in the case of the engine exhibited, or an ordinary one, according to the circumstances of each particular case. The air pump, which is placed vertically, as being preferable to horizontally, is worked by a connecting rod from the end of the crosshead of the large cylinder.
The nearest approach that it is possible to obtain to perfectly uniform rotative power is arrived at by constructing from calculation, the indicator figure, that would be produced by each cylinder, and deducing therefrom the requisite proportions that should exist between their two diameters, and the points at which the steam should be cut off, in each respectively.
In connexion with the above described engine, is exhibited PERKIN'S PATENT SURFACE EVAPORATOR CONDENSER the advantages of which may be summed lip as follows, viz:—The supply of perfectly pure water to the boiler, which infallibly prevents all incrustation and priming. The more regular supply of water to the boiler. The condensers are cheap and very portable. Dirty or salt water is capable of being used for condensation and existing high-pressure engines, may, by its use be converted at a moderate cost into condensing engines, and a very considerable increase of power obtained, without any additional consumption of fuel.