Cost Saving Example 1

$2,045.22 Annual Air Savings On A Flat Panel Display Blowoff

A flat panel display manufacturer runs 3 shifts. It takes a 40 second cycle to produce one fully assembled display. Prior to packaging, they use EXAIR’s 12″ (305mm) Super Ion Air Knife at 40 PSIG (2.8 BAR) to blow across the display to remove any static electricity, dust, debris and plastic flash from the panel surface. The air ran constantly. The displays are under the airflow only 10 seconds. Thirty seconds pass until the next display is in position. They manufacture 675 displays per shift (7.5 hrs.) for a total of 2,025 displays manufactured per day.

The timer was set to the “interval” setting when detecting the flat panel displays. The sensor was mounted 25mm (1”) prior to the Super Ion Air Knife blowoff station. When it detected the flat panel, it turned the air on immediately and started the 10 second timing sequence for closing the valve (shutting the air off). In the event the conveyor stopped, the air would no longer cycle on again until the next flat panel was detected.

Old Method

EXAIR’s 12″ (305mm) Super Ion Air Knife was supplied at 40 PSIG to clean the displays.
At 40 PSIG, EXAIR’s 12″ (305mm) Super Ion Air Knife consumes 20.4 SCFM (577 SLPM).
Non-stop blowing of 1,440 minutes (24 hours) per day X 20.4 SCFM = 29,376 SCF (831,341 SL) air usage per day.

EFC Solution

The EFC was installed to shut off the compressed air for 30 seconds of the 40 second cycle. (Turns air off for 75% of the cycle.)

Cost Difference

Most large plants know their air cost. If the actual cost is unknown, $0.25 per 1,000 SCF (28,329 SL) is reasonable.

Before the EFC installation:
29,376 SCF/1,000 = 29.38 X $0.25 = $7.34 air cost per day.

With the EFC installed:
The EFC shut the air off during the three 30-minute shift changes. Upon sensing the display, the timer turned on the compressed air for only 10 seconds of each 40 second cycle (25% of the time).

1,440 minutes per day – 90 minutes between shifts = 1,350 minutes of operation per day
1,350 minutes x 25% = 337.5 minutes of air per day
337.5 minutes x 20.4 SCFM = 6,885 SCF (194,846 SL) air usage per day
6,885 SCF/1,000 = 6.89 x $0.25 = $1.72 air cost per day
$7.34 (old air cost) – $1.72 (new air cost)
= $5.62 savings per day x 7 days per week
= $39.33 savings per week x 52 weeks per year
= $2,045.22 savings per year