A few months ago, my counterpart Brian Bergmann wrote a blog providing a detailed explanation of ROI or Return on Investment. Today, I would like to take this information and apply it to a common situation we deal with regularly here at EXAIR – replacing drilled pipe with our Super Air Knife.
Sections of pipe with drilled holes across the length are very common as they are made of relatively inexpensive materials and simple to make. Where the cost begins to add up is on the operation side as these types of homemade blowoffs waste a ton of compressed air, making them expensive to operate.
For comparison, lets look at a 12″ section of pipe with (23) 1/16″ diameter drilled holes. According to the chart below, each hole will flow 3.8 SCFM @ 80 PSIG for a total of 87.4 SCFM.
With an average cost of $ 0.25 per every 1,000 SCF used (based on $ 0.08/kWh), it would cost $ 1.31 to operate this blowoff for 1 hour. (87.4 SCFM x 60 minutes x $ 0.25 / 1,000)
Now let’s take a look at replacing the drilled pipe with our 12″ Super Air Knife. A 12″ Super Air Knife will consume 34.8 SCFM (2.9 SCFM per inch) when operated at 80 PSIG. Using the same figure of $ 0.25 per every 1,000 SCF used, it would cost $ 0.52 / hr. to operate this knife. (34.8 SCFM x 60 minutes x $ 0.25 / 1,000)
Now that we know the operating costs, we can make a better comparison between the 2 products.
Drilled pipe operating costs:
$ 1.31 per hour
$ 10.48 per day (8 hours)
12″ Super Air Knife costs:
$ 0.52 per hour
$ 4.16 per day (8 hours)
$ 10.48 per day (drilled pipe) – $ 4.16 per day (Super Air Knife) = $ 6.32 savings per day
A 12″ aluminum Super Air Knife carries a LIST price of $ 297.00. If we take $ 297.00 divided by $ 6.32 (saving per day), we get a ROI of only 47 days.
As you can see, it is quite beneficial to consider ALL of the parameters when looking at a process or application, rather than just the “upfront” details. What seems like a simple and easy fix, can actually be quite wasteful when it comes to the true cost of ownership.
If you are using similar devices in your plant and would like to see how an EXAIR Intelligent Compressed Air Product can help make the process operate more efficiently, contact an application engineer for assistance.