952

THE COLLIERY GUARDIAN.

November 17, 1916.

or more of these valves is automatic in action, the others
being arranged to be opened or closed by hand. As all
the steam used by the turbine has to pass the throttle
valve, all the nozzle valves are under the control of the
regulating governor.

In all parts of the turbine where the relative surface
speeds are high, and the clearance comparatively small,
such as at the periphery of the blades or of the dummy
strips, the tips are made thinner than the body of the
blades, so that, should the metal surfaces come into
contact from any cause—such as, for instance, water being

running. There is also an emergency governor which
acts when the speed is increased to 10 per cent, above
normal, by releasing a trigger which permits the
emergency valves to close.

A rotary oil pump, driven from the turbine shaft by
helical gearing, draws oil through a strainer from the
reservoir in the bed, and forces a copious and continuous
supply, under pressure, through a multitubular cooler
to the bearings, and thence back to the reservoir. The
discharge from each bearing is led into an independent
trough, so that by lifting a light aluminium cover on

elevator, both delivering the dirt into the scraper, which
conveys it to the bunker. The washed coal is then
screened on the vibrating screens into nuts and fine
coal, the nuts passing down a spiral into the bunker.

The fine coal with the washing water collects in the
pump sump, the smudge elevator delivering the coal
into the fine coal washer box, the dirt being elevated by
the dirt elevator into the dirt bunker. The washed
fine coal then flows to the drain sieves, over which it
passes into the bunkers.

The water and slurry drained from the fine coal on

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carried over with the steam from the boilers in large
quantities—the tips will quickly clear themselves without
risk of damage.

The end thrust exerted by the steam on the reaction
blades is balanced by dummy pistons, one for each step
of the rotor. Any slight unbalanced end thrust is taken
by a thrust block of ample bearing area, whose chief
function, however, is to fix the position of the rotor
endwise in the cylinder.

A spring controlled centrifugal governor regulates
the speed, so that the rise or fall, when full load is
thrown off or on, shall not exceed per cent., and at all
loads the governor is free from hunting. The speed can
be varied by hand 5 per cent, while the turbine is

the bed, the quantity of oil flowing from each bearing
can be readily observed.

Washery Plant.

The washery, which has a capacity of 80 ignis per
hour, is of the Baum type, and was erected by the
Simon-Carves Company Limited. No combustible
material is used in the construction of the washery
building itself, the materials being iron, brick and
cement.

The small coal is taken from the tables to the feed
hopper, a distance of 97 ft., by a belt conveyor 18 in.
wide, and then into the washer box. The heavy dirt is
drained in the dirt elevator and the light dirt in another

the sieves, collect in the pump sump, and are delivered
by a centrifugal pump into the settling tank, the slurry
returning to the slurry refiner, where it is drained and
then mixed with the fine coal in the bunker. All the
washed products are then loaded in the railway wagons
from their respective bunkers.

The special features of the Baum washery are : (1)
Actuating washing water with compressed air; (2) the
automatic recovery of all slurries, mixing and draining
same continuously along with the fine coal, by means of
the “slurry refiner"; (3) clarification of all washing
water in the elevated settling tanks. Any coal below
3£ in. mesh is washed by the Valleyfield washer.

The water is actuated by compressed air, at about