Tag: homemade

Super Air Knife to the Rescue in Machining

Published on by johnball2014Leave a comment
Home-made blow-off device

As machined parts require tighter tolerances, the surface has to stay clear during turning operations.  A customer that had a CNC machine needed to make a metal tube with a specific diameter.  The metal tube was 17 ½” (445mm) long.  They made their own blow-off “tree” to keep the surface clean from shavings.  They used five open ports to blow at the part surface (reference photo above).  When they started using their home-made device, they were not getting a consistent cleaning during operation.  They wanted to speak to an expert in this type of area, and they contacted EXAIR to see if we could improve their process.

With a series of open nozzles, it is very difficult to get a consistent force along a linear line.  The air becomes very turbulent, which has changing directions of air flow.  It creates a hazardous noise exposure to the operators, and it also wastes compressed air which costs the company a large amount of money to use.  With laminar air, the path flows in the same direction.  This creates a very consistent force with less noise.  Since air is invisible, I like to use water to show the difference.  The photo below shows turbulent and laminar flows. 

Turbulent to Laminar Water

For linear blow-offs, EXAIR offers a wide range of Super Air Knives.  They give a laminar flow pattern along the entire length.  We have stocked lengths from 3” (76mm) up to 108” (2.74 meters) in different materials.  A benefit of the Super Air Knife is the high amplification ratio of 40:1.  This means that for every 1 part of compressed air, it will entrain 40 parts of ambient air.  So, they are very efficient, safe, and effective.  For the application above, I recommended the model 110218 18” Super Air Knife Kit to cover the length of the metal tube.  It has an 18” (457mm) wide air stream that is very powerful to remove chips during the turning operation.  The kit includes a filter, regulator, and shim set.  The filter will remove contaminants from the compressed air system to keep the surface clean.  The shim set and regulator provide the ability to adjust the air to the ideal force level to remove the debris from the surface of the tube. 

Super Air Knife Kits include a Shim Set, Filter Separator, and Pressure Regulator.

One of the biggest attributes that the EXAIR Super Air Knives can offer is that they use much less compressed air than a series of open nozzles. With the engineered design, it can entrain large amounts of ambient air which means that less compressed air is required.  For the nozzle tree, it was using 105 SCFM of air at 80 PSIG.  The model 110218 only requires 52.2 SCFM at 80 PSIG. That is a difference of 52.8 SCFM; half the amount of compressed air as the home-made nozzles. 

Once they installed the Super Air Knife, the first thing that they noticed was the reduction of noise. The model 110218 Super Air Knife only has a noise level of 69 dBA at 80 PSIG, compared to a noise level of an open port which was over 100 dBA. By replacing the nozzle tree with the Super Air Knife, this company…

1. reduced air consumption

2. saved money

3. reduced noise levels

4. increased the effective blowing force

If you find yourself using a home-made blow-off device, you can be creating a hazardous, costly, ineffective method to “do a job”.  Since precision was needed for the company above, they were delighted to contact an expert in this area.  You can also improve your blow-off device by contacting an Application Engineer at EXAIR for assistance.  We would be glad to help. 

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

Super Air Knife Saves Money Compared to Drilled Pipe

Published on by exaircorpLeave a comment

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.

Drilled pipe – easy to make but extremely wasteful

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)

Super Air Knife – Available from 3″ up to 108″ in aluminum, 303ss and 316ss

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)

Cost Savings:
$ 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.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Replacing Home Made Blow Offs

Published on by Dave WoernerLeave a comment

Yesterday, I took a call from a customer, who had successful replaced a low cost blow off station with (2) of 6″ Super Air Knife.  The low cost blow off station was made up of two flexible lines with plastic liquid coolant nozzles to dry two surfaces after a roll forming process.  At the beginning of every production run, the nozzles would have to be positioned to hit the surface of the part because the flexible line would not hold its position.  On top of that even though these nozzles were blowing 74 SCFM of compressed air at 80 PSIG, the blow off was ineffective and left moisture on the parts after the run, which lead to corrosion on the parts during storage.

Before

  image

The (2) six inch Air Knives improved this process in three ways.  First, he never needed to reposition the nozzles after a production run.  Using the 1/4-20 threads in the bottom of the air knife, the customer was able to mount the air knife directly to the machine, which was a more robust system than the flexible liquid coolant hose. Second, the knives only consumed 35 SCFM of compressed air reducing his air consumption by half.  By utilizing the 40:1 amplification ration of the air knife, the customer had a much lower demand on the compressed air system, while getting the job done.  Finally, he left his customers happy with no corrosion marks on the parts after they had been stacked and delivered.  With no complaints about the quality at his customer, our customer will be able to improve his relationship with his customers and improve his business.

AFTER

after

Dave Woerner
Application Engineer
davewoerner@exair.com
@EXAIR_DW