The Horizontal Steam Turbine For Stationary Plants 1920
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to insure quiet running. It is made of
forged, open hearth Steel perfectly ground
and finished.
It is carried in two bearings: (aFz) of the
ring-oiled type and (bF8) a ring-oiled thrust
bearing designed to prevent endwise move-
ment and to hold the bucket wheels (aF6
and bF6) in the correct position relative to
the vertical plane of the nozzles (H, Fig.
3) and the stationary guide vanes (Ai).
The wheels (aF6 and bF6, Fig. 2) keyed to
the shaft are forged Steel circular disks. A
separate wheel is provided for each row of
buckets.
The buckets are made of nickei bronze and
are securely fixed to the rim of the wheel.
Metallic ring packing (A3, Fig. 2) is fitted
to the shaft to prevent leakage of steam from
the wheel case (A, Fig. 3) outward, or of air
inward.
In the multi-stage construction of the im-
pulse type turbine, the steam leakage from
stage to stage is prevented by the use of a
labyrinth packing (Fig. 6). Carbon pack-
ing (Fig. 5) is also employed.
The Turbine Casing
Fig. 3 illustrates a view from above of an
impulse type turbine with the top half of the
Fig. 2. Two disk rotor, bearings and go vernor
wheel case (A) lifted off and the rotating
parts and bearings (shown in Fig. 2) re-
moved.
The individual steam nozzles (H, Fig. 3)
by which the steam is directed upon the first
row of moving buckets on the wheel (aF6,
Fig. 2) are also shown.
Inasmuch as full steam expansion takes
place in the nozzles, the only parts of the
turbine which come in contact with steam at
boiler pressure and temperature are the
governor val ve (Hy, Fig. 3), the steam chest
Fig. 3. Interiör of lower half of casing
(H2) and the inlet ends (not shown) of the
nozzles (H).
No internal parts (Fig. 2) are subjected to
temperature of steam higher than that cor-
responding to the pressure of the expanded
steam from the nozzles (H, Fig. 3).
The intermediate guide vanes (Ai, Fig. 3)
re-direct the steam from the moving buckets
of the first wheel (aF6, Fig. 2) to the moving
buckets of the second wheel (bF6).
The bearing brackets (F2, F8, Fig. 3) are
supported directly upon the turbine casing
and are quite separate from the stuffing boxes
(H3), which prevent the leakage of steam or
water from the casing (A) into the bearings
or oil reservoirs (F2, F8).
The Reaction Type Turbine (Fig. 4)
The Turbine Casing
The turbine casing (A) is built of cast iron
in two parts, bolted together in the hori-
zontal plane of the center of the turbine
shaft. It is a steam-tight cylinder in which
are fixed the stationary blades (Az) used for
re-directing the steam from one set to the
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