October, 2003
|
Volume 2,
Issue 10 |
Download Printable
Version (pdf)
Upgrade Your Compressed Air Blow-Off
System
for Energy Savings
Are you considering upgrading your
existing compressed air blow-off system?
Need more power or shorter cycle times?
High-efficiency centrifugal blowers can
provide energy savings as well as a
performance upgrade to your existing
compressed air blow-off system for
substantially less than your current
system’s operating costs.
What
is your air blow-off system wish list?
• More power?
• Faster conveyor line speed?
• Better drying rate?
• Lower electrical cost?
In today’s competitive business
environment, both large and small
manufacturers are striving towards
reducing their cost base. Making a fresh
appraisal of compressed air as well as
inefficient blower-driven air blow-off
systems can make real economic sense.
Re-engineering is not just a trendy
buzzword, but a practice that has proven
beneficial in modernization or upgrading
of existing industrial processes which
are using compressed air. Enhanced
capital allowances (ECA) are the carrot
that the Government has extended to
encourage investment in new
energy-efficient products.
Data gathered from case studies* of
programs by the
United States Department of Energy’s
Office of Industrial Technology
suggests excellent paybacks based on
energy savings alone:
| Type of Plant |
Annual Cost Savings ($US) |
Payback (years) |
Savings** |
| Strand Board |
$85,100 |
1.0 |
50% |
| Municipal
Sewage |
$2,960 |
5.4 |
17% |
| Beer Brewing |
$19,000 |
0.1 |
52% |
| Metal
Fabrication |
$68,000 |
1.5 |
38% |
**As percent of
initial electricity usage*Data
Gathered from the U.S. Department of
Energy's "Motor Challenge Program."
Savings is relative to energy
consumption prior to the downsizing of
air compressor motors.
Blower driven blow-off technology is
simply more efficient than compressed
air; it can provide staggering savings.
Depending on your conditions, the
savings may be up to 90%, meaning
that an investment in a blower driven
solution pays for itself in a very short
period—four or five months is not
uncommon.
A second payback is productivity
increase—more widgets-per-hour
processed. This increase in productivity
can be considerable and by itself could
justify the investment in upgrading.
Whether your requirements have
changed in terms of the quantity or
quality of your blow-off system
requirements, upgrading is a
cost-effective and reliable solution.
Air
Blow-Off System Selection & Plant
Productivity
Selection of a high efficiency
industrial blower will mean higher flow
or pressure allowing for more
widgets-per-hour to be processed. How
much is a five or ten percent
productivity increase worth?
Compressed Air Systems vs. High
Efficiency Blowers
The bottom line to a manufacturing
plant owner/operator is the cost of
blow-off air per SCF. The cost per SCF
of air is dependent upon the efficiency
of the compressed air system or blower
system used to produce the air.
When comparing compressed air
blow-off systems to high efficiency
blower systems, one needs to compare
annual electrical cost and return on
investment (ROI) for various air
blow-off systems available. Too often
only the initial cost is considered, not
the day-to-day operating costs.
For comparison we will consider three
typical compressed air delivery systems:
the homemade drilled pipe; single bore
or flat fan nozzles mounted on a pipe;
and the bar type air knife. When
operating at 60 psig, the 18-inch pipe
systems will each flow approximately 290
SCFM and the bar air knife with a 0.003”
gap will flow 130 SCFM. Approximately 72
compressor horsepower are required to
produce a flow of 290 SCFM. Similar
blow-off results can be achieved with a
75% efficiency blower, requiring only 5
horsepower to flow 324 SCFM.
At the US average electrical cost of
$0.083 per kW-hr, the power cost for the
5-HP blower equals $1,358. For the 72-HP
compressor, the power cost is $21,399.
The power cost represents approximately
65% of the total cost of the compressor
over a 7-year period. In addition to
power cost, annual maintenance expenses
add an additional 20% to overall cost.
Upgrading from a 72-HP compressor to
an
AirPower™ blower yields an annual
savings of $20,000 in electrical costs.
This is not a one-time savings; it is
year-after-year. For a 7-year
period the savings would be $140,000.