We illustrate one of the largest Corliss engines ever constructed. It is
of the single cylinder, horizontal, condensing type, with one cylinder
40 inches diameter, and 10 feet stroke, and makes forty-five revolutions
per minute, corresponding to a piston speed of 900 feet per minute. At
mid stroke the velocity of the piston is 1,402 feet per minute nearly,
and its energy in foot pounds amounts to about 8.6 times its weight.
The cylinder is steam jacketed on the body and ends, and is fitted with
Corliss valves and Inglis & Spencer's automatic Corliss valve expansion
gear. Referring to the general drawing of the engine, it will be seen
that the cylinder is bolted directly to the end of the massive cast iron
frame, and the piston coupled direct to the crank by the steel piston
rod and crosshead and the connecting rod. The connecting rod is 28
feet long center to center, and 12 inches diameter at the middle. The
crankshaft is made of forged Bolton steel, and is 21 inches diameter at
the part where the fly-wheel is carried. The fly driving wheel is 35
feet in diameter, and grooved for twenty-seven ropes, which transmit the
power direct to the various line shafts in the mill. The rope grooves
are made on Hick, Hargreaves & Co.'s standard pattern of deep groove,
and the wheel, which is built up, is constructed on their improved plan
with separate arms and boss, and twelve segments in the rim with joints
planed to the true angle by a special machine designed and made by
themselves. The weight of the fly-wheel is about 60 tons. The condensing
apparatus is arranged below, so that there is complete drainage from the
cylinder to the condenser. The air pump, which is 36 inches diameter and
2 feet 6 inches stroke, is a vertical pump worked by wrought iron
plate levers and two side links, shown by dotted lines, from the main
crosshead. The engine is fenced off by neat railing, and a platform with
access from one side is fitted round the top of the cylinder for getting
conveniently to the valve spindles and lubricators. The above engraving,
which is a side elevation of the cylinder, shows the valve gear
complete. There are two central disk plates worked by separate
eccentrics, which give separate motion to the steam and exhaust valves.
The eccentrics are mounted on a small cross shaft, which is driven by a
line shaft and gear wheels. The piston rod passes out at the back end of
the cylinder and is carried by a shoe slide and guide bar, as shown more
fully in the detailed sectional elevation through the cylinder, showing
also the covers and jackets in section. The cylinder, made in four
pieces, is built up on Mr. W. Inglis's patent arrangement, with separate
liner and steam jacket casing and separate end valve chambers. This
arrangement simplifies the castings and secures good and sound ones. The
liner has face joints, which are carefully scraped up to bed truly to
the end valve chambers. The crosshead slides are each 3 feet 3 inches
long and I foot 3 inches wide. The engine was started last year, and
has worked beautifully from the first, without heating of bearings or
trouble of any kind, and it gives most uniform and steady turning. It is
worked now at forty-one revolutions per minute, or only 820 feet piston
speed, but will be worked regularly at the intended 900 feet piston
speed per minute when the spinning machinery is adapted for the increase
which the four extra revolutions per minute of the engine will give; the
load driven is over 1,000 horsepower, the steam pressure being 50 lb.
to 55 lb., which, however, will be increased when the existing boilers,
which are old, come to be replaced by new. Indicator diagrams from the
engines are given on page 309. The engine is very economical in steam
consumption, but no special trials or tests have been made with it. An
exactly similar engine, but of smaller size, with a cylinder 30 inches
diameter and 8 feet stroke, working at forty-five revolutions per
minute, made by Messrs. Hick, Hargreaves & Co. for Sir Titus Salt,
Sons & Co.'s mill at Saltaire, was tested about two years ago by Mr.
Fletcher, chief engineer of the Manchester Steam Users' Association, and
the results which are given below pretty fairly represent the results
obtained from this class of engine. Messrs. Hick, Hargreaves & Co. are
now constructing a single engine of the same type for 1,800 indicated
horse-power for a cotton mill at Bolton; and they have an order for a
pair of horizontal compound Corliss engines intended to indicate 3,000
horse-power. These engines will be the largest cotton mill engines in
the world.--_The Engineer_.
[Illustration: 1000 HORSE POWER CORLISS ENGINE.--BY HICK. HARGREAVES &
CO.]
_Result of Trials with Saltaire Horizontal Engine on February 14th and
15th, 1878. Trials made by Mr. L.E. Fletcher, Chief Engineer Steam
Users' Association, Manchester._
Engine single-cylinder, with Corliss valves. Inglis and Spencer's valve
gear. Diameter of cylinder. 30in.; stroke, 8ft.; 45 revolutions per
minute.
No. of trials
Total 1.H.P.
[MB] Mean boiler pressure.
[MP] Mean pressure on piston at beginning of stroke.
[ML] Mean loss between boiler pressure and cylinder.
[MA] Mean average pressure on piston.
[W] Water Per I.H.P. per hour.
[C] Coal per I.H.P. per hour.
No. of trials Total MB MP ML MA W C
I.H.P. lb lb lb lb lb lb
Trial No. 1. 301.89 46.6 44.11 2.53 21.23 18.373 2.699
Trial No. 2. 309.66 47.63 44.45 3.18 21.67 17.599 2.561
Means. 305.775 47.115 44.28 2.855 21.45 17.986 2.630
[Illustration: 1000 HORSE POWER CORLISS ENGINE.--BY HICK, HARGREAVES
& CO.] [Illustration: 1000 HORSE POWER CORLISS ENGINE.--BY HICK,
HARGREAVES & CO.]
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