The Sidney herald., 1958-10-15
THE PLANT

THE PLANT
The plant has a 200-foot con-
crete stack adjacent to the main
structure. The new Montana-Da-
kota Utility Co. addition is the
most modern addition to its cleo
trio production system.
Nearly 5000 cubic yards of con-
crete was used in building forms
and excavations to support the
building, boiler fuel bunkers and
other complex and heavy equip
ment that is capable of converting
lisp tons of Eastern Montana lig-
mite to 100000 kilowatt hours of
electricity every day. The maxi
mum electrical rate of capability
of the station is $4,000 kilowatt,
a rate sufficient to supply the peak
electric demand of a modern city
of 100000 population.
A boiler capable of supplying
425,000 pounds of steam per hour,
at a pressure of 1850 pounds per
square inch and a temperature
of $50 degrees F. was selected.
The specifications required that
this steam delivery be attained
by burning either eastern Mon
tana Ignite or natural gas, sin
ely or in combination. The lig-
mite will be burned in finely pull
verified form, such preparation
taking place in three coal pull
verizers or mills. Whether gas or
coal is burned, it will be fired
"tangentially" into the corners of
the "waterwalled" furnace, which
is 90 feet in height, 20 feet wide
and 10 feet deep. The combus-
ton space will thus accommodate
a swirling cyclone of flame. The
boiler, or more properly, the
"steam generator" together with
the burners and coal mills are
manufactured by Combustion En-
cheering, Inc.
A 600 HIP. fan supplies air to
the furnace and a 1850 HIP. fan
induces or pulls" the spent flue
gases from the boiler enclosure,
iischarging them to the 200-foot
stack. Before the flue gases are
discharged, however, all disable
heat is reclaimed by an air heat
or which preheats the air being
supplied to the furnace. Also, the
flue gases are scrubbed" clean
Of fly ash particles in a massive
device known as a dust c%ollec-
Steam from the boiler is taken
through heavily insulated special
alloy steel pipe to the General
Electric turbine = generator set,
the thermal energy of the
high pressure, high temperature
steam is converted to rotating en-
ergy, driving the generator at
$500 RPM to provide electric cur
rent at 1890 volts.
Spent steam, at pressures with
in II pound per square inch of a
perfect vacuum and at about
room, temperature, is exhausted
from the turbine to the condenser
where it is cooled and condensed
to water for pumping back to the
boiler through one of two 1850
HIP. boiler feed pumps and an
other trip through the cycle.
To condense the spent steam,
%, 000 gallons of water per min
ute will be pumped from and re-
turned to the Yellowstone River.
Except for a very slight tempera-
ture increase, this water is re-
turned to the river unchanged
and uncontaminated.
The heavy natural silt loading
of the Yellowstone River and its
wide and violent variations in
level required that special de-
sign features be Incorporated in
the intake" structure, a separate
building located Immediately adj
jacent to the river.
Two specially designed pumps,
with parts made of abrasion re-
sistant alloys, will each supply
1900 gallons of water per min
ute to plant cooling services. The