1392

THE COLLIERY GUARDIAN.

June 19 1914.

MATHER & PLATT, LTD.

Messrs. Mather and Platt Limited show a variety of
turbine and centrifugal pumps. These include an axial-
flow turbine pump direct coupled to a Zoelly steam
turbine. The pump is capable of delivering 3,600 gallons
per minute against a total head of 60 ft. when running at
3,000 revs, per minute. This type of pump is of a new
design, and constructed to deal with large quantities of
water against low heads at comparatively high speeds.
The high speed compared with the normal type of
centrifugal pump enables this type to be direct driven

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Fro. 1.—Axial-flow Turbine Pump coupled to Zoelly Turbine.

Fig. 2.—Multi-stage High-lift Turbine Mine Pump.
(Mather and Platt Limited.)





Fig. 3.—’Section through Multi-stage High-
lift Turbine Pump.

Fig. 4.—Diagram of Connections of Turbine
Boiler Feed Pump.

(Mathex and Platt Limited.)

by high speed motors and steam turbines with a con-
sequent reduction in first cost and space occupied. The
pump is designed as a two-chamber pump, each
chamber being fitted with a propeller of special design,
and working in parallel. The water enters in a central
suction chamber, and is then distributed equally to the
right and left hand pump chamber, from whence it is
delivered through a breeches pipe into the common
delivery main. Guide passages of special design at the
entrance and exit of the propellers ensure the correct

flow of the water through the channels of the propellers.
It is characteristic of this type of pump that the load
becomes larger when the output for which they are
designed is reduced, and this load is a maximum when
the delivery is stopped altogether. A by-pass arrange-
ment is therefore fitted to the pump between delivery
branch and suction chamber, so as to short circuit the
water in proportion as its delivery through the delivery
main is restricted. The by-pass arrangement also
enables the plant to be started up with the minimum
load, a feature which is of great advantage when the

pump is driven by squirrel cage A.C. motor. This
type of pump is also arranged to be fitted with an air
extracting pump, gear driven from the main shaft to
exhaust the air from the suction pipe and pump casing
on starting up. The small pump is automatic, so that
in the event of the main pump losing its water it imme-
diately comes into action and reprimes the latter.



Fig. 5.—Centrifugal Sludge Pump.

(Mather andJPlatt Limited.)

There is also multi-stage high lift turbine pump
for mine work capable of delivering 700 gallons per
minute against a total head of 720 ft. at 1,160 revs, per
minute. This pump absorbs 210-b.h.p., and is arranged
to be driven by a three-phase high-tension motor. The
pump is divided into vertical sections securely held
together by external bolts of ample strength, this con-
struction giving the greatest ease of dismantling, and
allowing the addition of an extra section should it be
desired to increase the head at any time. Feet are
provided on each middle body of the larger sizes, rest-
ing on the planed surface of the bed, and allowing each
body to be drawn clear of the shaft without damaging
the latter. The whole of the working parts of the pump,
both rotary and stationary, can be constructed of gun

metal, and are easily renewed. The axial thrust is
balanced by an improved automatic compound differen-
tial balancing arrangement. This consists of a balance
disc with two active throttling surfaces floating between
two fixed seatings with minimum clearance. Both the
working faces are arranged vertically so as to be inde-
pendent of all possible vibration of the rotary system.
The high pressure water, escaping from the rim of the
last impeller, passes through the holes H into the pres-
sure chamber M, from whence it escapes along the
larger throttling surface of the balance valve into the
regulating pressure chamber K, and from there past
the smaller throttling surface into the escape pipe P,
leading back into the suction chamber of the pump. A
multiplication of the balancing effect is obtained by the
closing up of the larger throttling face causing an open-
ing out of the smaller one, and a movement of a few
thousandths of an inch only is required to balance the
most extreme and sudden changes of the hydrostatic
equilibrium of the pump. The other, and most impor-
tant feature of this auto-plate balance is that it main-
tains the central position of the impellers, even if the
throttling surfaces have become worn, as may be the
case when pumps are working on gritty water. A
multi-stage turbine pump for boiler feed coupled direct
to 15-b.h.p. direct current motor is capable of supplying
2,400 gallons per hour to high pressure boilers at a
pressure of 1601b. per sq. in., and simultaneously 3,600
gallons per hour to low pressure boilers at 80 lb. per
sq. in. when running at 1,700 revs, per minute. Both
discharges can be taken through the economisers or
direct to the boilers. Alternatively the whole quantity of
6,000 gallons per hour can be delivered to either the low
or high pressure boilers. The outstanding feature of
the boiler feed pump is the possibility of arranging three
separate circuits for the water delivery. One circuit is
taken from the suction through the valve A, part of the
turbine pump B, valve C, through the economisers D,
valve E, to the low pressure boilers. Part of the
delivery from the same circuit is taken through valve F
into the remaining portion of the pump, and through
valves H and J, and delivered into the high pressure
boilers. Should it, however, be necessary to shut the
economisers down, or should a breakage occur in the
pipe line from the pump to the economisers it is pos-
sible by closing valves C and F and opening valves G,
to pump from the suction through valves A, B, G, H,
and J direct into the high pressure boilers. A feature
of this arrangement is that any of the valve connections
might be closed or opened at any time, thus changing
the circuits without stopping the plant. The motor is
of the latest design and fitted with a sliding cover at the
commutator end, so as to enable the brush gear to be
inspected when necessary. A standard centrifugal pump
is shown coupled to induction motor for dealing with
1,700 gallons per minute against 60 ft. head at 1,150 revs,
per minute. There is also a 6 in. belt driven centrifugal
pump of special design to deal with sludge, sewage and
the like. The capacity is 600 gallons per minute against
30 ft. head at 1,000 revs, per minute—the features of
interest on this pump are the swing cover on the suction
side to facilitate inspection and the open type of
impeller.

TILGHMAN’S PATENT SAND BLAST CO. LTD.

This firm show one of their vertical high-speed
enclosed air compressors, fitted with patent multiple
plate valves. The compressor is direct driven from
motor shaft, and has a capacity of 400 cu. ft. of air per

Vertical High-speed Compressor.

(Tilghman’s Patent Sand Blast Company Limited.)

minute. This type of machine is arranged to compress
the air in two stages, each stage being complete in a
separate double-acting cylinder. The machine is
entirely automatic both as regards oiling and air pres-
sure, any required pressure of air being maintained in
the air receiver, irrespective of the quantity of air being
used. The design allows of every portion of the motion
work and valves being readily inspected and taken
apart. The air cylinder valves run quietly at all