TECH BUZZ // FLUID HANDLING
DOES YOUR PLANT HAVE
Hunting for High Quality Gears?
11715 Main Street, Roscoe, IL 61073
US Navy MH-60S Seahawk helicopters patrolling for mines out ahead
of surface vessels use a powerful and precise Carriage Stream Tow and
Recovery System (CSTRS) to quickly raise and lower mine-hunting and
destruction equipment. Very high-precision gears from Forest City Gear
help to ensure that the mission goes as planned.
Don’t let gear challenges go undetected.
1 A large tissue mill in the Midwest upgraded its packaging operations,
adding a new high speed casepacker.
Overnight utilities needed a fourth 500
hp centrifugal compressor, the stand-by
unit, to ensure the casepacker would
Our investigation four months later
discovered 150 feet of ¾-inch steel air
line supplying the machine (and half-inch
valves and pipe nipples at the 1-inch size
air supply regulator on the casepacker
unit). The construction crew simply
located the nearest blanked-off air line
connection on the 2-inch header in the
bay to supply the new equipment.
The reason given was that the mill did
not want to take a total air system down to
install a 1-inch connection on the 2-inch
air line above the machine. At 6 cents a
k Wh, the fourth compressor and air dryer
were costing an additional $600 per day. It
took about 15 minutes to convince the mill
manager to schedule a two-hour shutdown (at the end of second shift) for an air
header connection above the new machine
and larger fittings at the regulator station.
2 A steel fabrication plant had a 300 hp rotary compressor supplying air for
two large production bays. Two new bays
were added next to the original two, and a
second 300 hp compressor was installed
in the compressor room next to bay 1.
It seemed to be a straightforward and
logical plant expansion. But that was
The compressors had to be operated at
125-128 psig to provide enough pressure in bays 3 and 4. The process team
considered that they had underestimated
air demand in the new bays. They were
planning a third compressor.
Our analysis discovered that the main
SOMETHING AS COMMON AS AMBIENT AIR CAN RUN INTO A LOT
of money when you need to compress it for use in driving a process.
At 10 cents per kilowatt-hour, operating an industrial motor continuously for three shifts costs about $2 a day for every 1 hp. Two 300 hp
compressors, for example, would cost about $1,200 per day for power.
Operating and maintenance costs would add another $250 per day.
That equates to over $500,000 per year of total operating cost.
In 30 years of evaluating industrial plant compressed air systems,
my company has come across a number of cases where money was
literally being thrown away because of an oversight or a bad decision.
Here are a few cases in point: