Tag: drilled pipe

What’s So Awful About A Drilled Pipe For A Conveyor Blowoff?

Published on by Russ BowmanLeave a comment

A technician from a company that performs comprehensive audits of compressed air systems called me with a sad, sad story. A client had just installed a brand-new state-of-the-art rotary scroll compressor with a variable speed drive…they were going all-out on efficiency, which is great. During the technician’s walk-through, however, he noticed a blowoff on a conveyor belt — they actually heard it before they could see it — a black iron pipe with a series of holes drilled along the length, plumbed with compressed air being supplied, unregulated, from a 100psig header.

The pipe was 18″ long and had 30 holes, 1/8″ diameter each, drilled along the length. From the table below, we can presume that this drilled pipe was consuming as much as 475.8 SCFM:

I say “as much as 475.8 SCFM” because the technician noted the holes were simply drilled through, they weren’t rounded, so I calculated the flow from a 1/8″ orifice at 100psig (26.0 CFM) with a 0.61 multiplier for sharp edges orifices. Also, the inlet pressure of the drilled pipe is not known. With a 1″ pipe supplying it, the flow could be limited to around 350 SCFM, due to line loss in the pipe.

The technician first asked about installing Air Nozzles in the drilled pipe. That’d mean drilling those holes out and tapping them individually. This COULD be done, and the drilled pipe could be fitted with 30 Model 1110-PEEK Nano Super Air Nozzles, with an air consumption of 8.3 SCFM @80psig each, for a total of 249 SCFM. That’s a significant reduction, but also a lot of work on the drilled pipe. I recommended replacing it entirely with a Super Air Knife.

A Model 110018 18″ Aluminum Super Air Knife consumes only 52.2 SCFM @80psig — almost an order of magnitude reduction! Let’s do the math on the costs:

First, the drilled pipe: Let’s give all the benefit of the doubt here and assume that the line loss had indeed limited the air consumption to 350 SCFM. Operating 8 hours a day, 5 days a week, 52 weeks a year, and using the US Department of Energy’s estimate that compressed air costs $0.25 per 1,000 Standard Cubic Feet used, the annual operating cost of the drilled pipe was $10,920.00:

350 SCFM X 60 min/hr X 8 hrs/day X 5 days/week X 52 weeks/year X $0.25/1,000 SCF = $10,920.00

Drilling & tapping those holes for EXAIR Nano Super Air Nozzles (8.3 SCFM ea X 30 = 249 SCFM total) would result in an annual operating cost of $7,768.80:

249 SCFM X 60 min/hr X 8 hrs/day X 5 days/week X 52 weeks/year X $0.25/1,000 SCF = $7,768.80

Replacing the drilled pipe with an EXAIR 18″ Super Air Knife (52.2 SCFM) drops the annual operating cost even further, to $1,628.64:

52.2 SCFM X 60 min/hr X 8 hrs/day X 5 days/week X 52 weeks/year X $0.25/1,000 SCF = $1,628.64

To put that further into perspective, the 2025 List Price for an 18″ Aluminum Super Air Knife is $533.00. It costs almost $9,300.00 per year LESS to operate than the drilled pipe. That means the Air Knife will have paid for itself in operating costs in just under 21 days.

To put that even FURTHER into perspective, the ~300 SCFM reduction in compressed air consumption is approximately 75HP worth of a typical industrial air compressor load. It’s not uncommon for a mid-to-large sized company to have more than one air compressor, and 50HP is a common size for a backup compressor. If that was the case in the facility that my technician caller was auditing, he’d be letting them know that this $533.00 investment that’s going to save them over $9,000.00 a year is ALSO going to allow them to shut down one of their air compressors. Completely.

So, THAT’S what’s so awful about a drilled pipe. If you have any in your facility, we should talk.

Russ Bowman, CCASS

Application Engineer
Visit us on the Web
Follow me on Twitter
Like us on Facebook

ROI: Super Air Knife vs. Drilled Pipe

Published on by John BallLeave a comment
Super Air Knife Drilled Pipe

Return on Investment, or ROI, is the ratio of profit over total investment.  Many people use it to check investment stocks, financial markets, capital equipment, etc.  It is a quantitative way in determining the validity for an investment or project.   You can use this ROI value to give a measurable rate in looking at your investment, no matter how big or small.  In this blog, I will compare the ROI between an EXAIR Super Air Knife to a home-made drilled pipe.  Let’s start by looking at Equation 1 to calculate the Return on Investment.  For a positive ROI value, the project will pay for itself in less than one year.  Any negative values would represent a high-risk investment. 

Equation 1:  ROI = (Total Annual Savings – Total Project Cost) / Total Project Cost * 100

The Total Project Cost is the cost of the product with the labor to install.  In our example, we will use a 36” (914mm) blow-off device to cover the width of a conveyor.  One device will be an inexpensive drilled pipe and the other will be a high-efficiency EXAIR Super Air Knife.  The drilled pipe had (72) 1/16” (1.6mm) diameter holes spaced ½” (13mm) apart.  EXAIR manufactures the model 110036 36” Aluminum Super Air Knife with a .002” (.05mm) shim along the entire length.  The model 110036 has a retail price of $802.00 each.  The cost of the home-made drilled pipe was around $70.00 for material and labor.  What a difference in price!  It seems like the ROI should be in the negative, but is it?

Let’s continue on with the Return on Investment.  The amount of time required to install the Super Air Knife across the conveyor only took a maintenance staff about one hour to mount.  The labor rate that I will use in this example is $80.00 per hour (you can change this to your current labor rate).  The labor cost to install the knife is $80.00.   The Total Project Cost can be calculated as follows: $802 + $80.00 = $882.00.  The next part of the equation, Total Annual Savings, is a bit more in-depth, but the calculation is below.

To calculate the Total Annual Savings, the amount of compressed air used by the drilled pipe is around 261 SCFM (7,389 SLPM) at 60 PSIG (4.1 Bar).  The model 110036 Super Air Knife has an air consumption of 82.8 SCFM (2,344 SLPM) at 60 PSIG (4.1 Bar).  With an electrical rate of $0.08 per Kilowatt-hour, the electrical cost is near $0.25 per 1000 standard cubic feet or compressed air, or $0.25/1000SCF.  To calculate an annual savings, let’s use a blow-off operation of 8 hours/day for 250 days a year.   Replacing the drilled pipe with the model 110036 Super Air Knife, it will save you (261 SCFM – 82.8 SCFM) = 178.2 SCFM of compressed air.  To put this into a monetary value, the annual savings will be 178.2 SCFM *$0.25/1000SCF * 60 Min/hr * 8hr/day * 250 day/yr = $5,346.00 per year.

With the Total Annual Cost and the Project Cost known, we can insert these values into Equation 1 to calculate the ROI:

ROI = (Total annual savings – Total Project Cost) / Project Cost * 100

ROI = ($5,346.00 – $882.00) / $882.00 * 100

ROI = 506%

With a percentage value that high, we are looking at a payback period of only 40 days.  You may look at the initial cost and be discouraged; but in a little over a month, the model 110036 will have paid for itself.  And after using it for one year, it will save your company $5,346.00. 

In my experience, a loud blowing noise from your equipment is generally coming from an inefficient and safety-concerned product.  With these “cheap” ways to blow compressed air, it will cost your company a lot of money to use as shown in the example above.  EXAIR has an Air Savings Calculator on our website to calculate the savings by replacing your inefficient blow-off devices. And, if you would like to team up with EXAIR to find ways to increase savings, improve productivity, and promote safety, you can contact an Application Engineer.  We can help you get started by defining your Return on Investment with EXAIR products.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

EXAIR Super Air Knife Promotion

Engineered Compressed Air Products = Less Noise & Money Saved

Published on by codybiehleLeave a comment

Everyone dislikes loud noises for the most part. Here in Ohio we just got done surviving the constant buzz and swarming of cicadas. We all deal with noise on a daily basis, some of it enjoyable and some of it not so much. Noise is an inescapable fact of life and all we can do is try to reduce noise level to save our sanity. But, did you know that cutting down on the noise produced by compressed air blow offs can actually save you money? Your loud homemade blow off system is not only way too loud, but it is most likely also costing you more money than you need to spend.

EXAIR’s engineered compressed air products are designed to operate quietly and efficiently. The reduction in noise they produce is only one of the benefits – another is the reduction in money by reducing compressed air use.

EXAIR Super Air Knife Promotion
EXAIR’s SUPER AIR KNIFE

But how does one calculate out the ROI? It is very simple to calculate out your potential savings of using one of EXAIR’s Intelligent Engineered Compressed Air Products. If you would rather not do the calculations out yourself then we can do it for you by sending the item in question to our Efficiency Lab Testing. The Efficiency Lab Testing is a free service that we offer to show you the possible savings by switching to one of our products.

The following is a typical ROI preformed and replaced with a corresponding EXAIR Super Air Nozzle:

  • ¼” drilled pipe with (3) 3/32” Holes which uses 9.4 SCFM per hole at 80 psig (denoted as DP)
  • A Model 110003 3” Super Air Knife can be used to replace and only uses 8.7 SCFM at 80 psig (denoted below as SAK)

Calculation:

(DP air consumption) * (60 min/hr) * (8 hr/day) * (5 days/week) * (52 weeks/year) = SCF used per year for Copper Pipe 

(28.2) * (60) * (8) * (5) * (52) = 3,519,360 SCF

(SAK air consumption) * (60 min/hr) * (8 hr/day) * (5 days/week) * (52 weeks/year) = SCF used per year for EXAIR Product 

 (8.7) * (60) * (8) * (5) * (52) = 1,085,760 SCF

Air Savings:

SCF used per year for DP – SCF used per year for SAK = SCF Savings

               3,519,360 SCF – 1,085,760 SCF = 2,433,600 SCF in savings

If you know the facilities cost to generate 1,000 SCF of compressed air you can calculate out how much this will cost you would save. If not, you can us $0.25 to generate 1,000 SCF which is the value used by the U.S. Department of Energy to estimate costs.

Yearly Savings:

                (SCF Saved) * (Cost / 1000 SCF) = Yearly Savings

                                (2,433,600 SCF) * ($0.25 */ 1000 SCF) = $608.40 annual Savings

With the simple investment of $216 (as of date published) you can calculate out the time it will take to pay off the unit.

Time Until payoff:

                (Yearly Savings) / (5 days/week * 52 weeks/year) = Daily Savings

                                ($608.40/year) / (5 days/week * 52 weeks/year) = $2.34 per day

                (Cost of EXAIR Unit) / (Daily Savings) = Days until unit has been paid off

                                ($216) / ($2.34/day) = 92.3 days 

As you can see it doesn’t take long for the air knife to pay for itself. You also get better overall performance as the Super Air Knife will provide a solid curtain of air. In the end you get to breathe a sigh of relief as no more jump scares and a loud hiss when you turn your air on. Who doesn’t like to save a little money and sanity, especially in these crazy times?

If you have any questions or want more information on EXAIR’s Air Knifes or like products. Give us a call, we have a team of application engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook

Compressed Air Vs. Blower Air Knife & Other Alternatives

Published on by 2 Comments

An often debated subject is whether it makes more sense to use a compressed air powered Air Knife or a blower powered Air Knife.  Initially, one might think that the blower option might be a more economical solution due to its slightly lower electrical consumption when compared to an air compressor.  However, a blower powered Air Knife is an expensive capital expenditure that requires frequent downtime, costly maintenance of filters, belts, bearings and electricity!  They also take up a lot of space and can produce sound levels that exceed OSHA noise level requirements.  EXAIR’s Super Air Knife even when operated at 80 PSIG (5.5 BAR), is surprisingly quiet at 69 dBA!

OSHA Chart

Another drawback for the blower powered Air Knives is the air volume and velocity can be difficult to control since these are adjusted mechanically.

Some other important maintenance considerations are:

  • Filters must be replaced every 1 – 3 months.
  • Belts must be replaced every 3 – 6 months.
  • Blower bearings wear out quickly due to the high rpm requirements.
  • The Seals wear and can allow dirt and moisture to enter, couple that with high temperature environments and the bearing life will be reduced.
  • Blowers typically add heat to the air flow, making it unsuitable for cooling applications.

In contrast the award winning and highly efficient EXAIR Super Air Knife represents our latest generation of innovation that dramatically reduces compressed air usage and noise, with no moving parts!

The EXAIR Super Air Knife is a great way to clean, dry or cool parts because they deliver a uniform sheet of laminar air flow across it’s entire length with force that can range from a gentle breeze to extreme hard-fitting force!

EXAIR Super Air Knives highly engineered design entrains ambient air at a ratio of 40:1.  This simply means that for every (1) part of compressed air supplied (40) parts of ambient air are pulled into the compressed air stream exiting the nozzle.

How Air Knife Works

1). Compressed air flows into the plenum of the Super Air Knife.  The flow is directed to a precision slotted orifice.

2). As the air-flow exits the air gap it follows a flat surface that directs the air flow in a perfectly straight line.  This creates a uniform sheet of air across the entire length of the Super Air Knife.

3).  Velocity loss is minimized and force is maximized as the room air is entrained into the primary air-stream at a 40:1 ratio.  This all results in a well defined sheet of laminar air-flow with hard hitting force.

Advantages of the Super Air Knife

  • Very Quiet, typically 69 dBA for most applications
  • Minimal Compressed air consumption
  • 40:1 air amplification
  • Uniform air flow across the entire length
  • Force and flow are variable
  • No moving parts – therefore maintenance free
  • Easy mounting – compressed air inlets are conveniently located on each end and the bottom
  • Compact design, rugged design and very easy to install
  • Recessed hardware
  • Stock lengths up to 108″ in Aluminum (max temperature of 180°F/82°C), 303SS or 316SS (max temperature 800°F/427°C)
  • PVDF is available up to 54″ long for superior corrosion resistance (max temperature 275°F/135°C)

EXAIR’s Super Air Knife is also a great replacement for other commonly used, but highly inefficient and noisy compressed air operated devices.

As an example, two commonly used blow-offs are the drilled pipe and flat air nozzles installed into a pipe.  EXAIR performed a head to head test employing the EXAIR Super Air Knife, Blower Powered Air Knife, Drilled Pipe & Plastic Flat Nozzles mounted in a pipe.

Below are the results of that test from a very common application, blowing water off bottles.  As shown in the First Year Cost Column it becomes clear that the true cost of ownership needs to be considered.  Many plants are surprised at how efficient the EXAIR Super Air Knife is compared to other alternatives.

AirKnifeComparisons

Another important consideration is how effective these other blow-off methods are.  The drilled pipe and flat air nozzles have “dead spots” where the air flow is non existent leaving some of your product wet and/or dirty.

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook