Tag: math

When You Get To Asheville

Published on by Brian FarnoLeave a comment
1 – Steve Martin & Edie Brickell – “When You Get To Asheville”

Over the past week, my amazing wife and I traveled to Asheville, NC for a long weekend away. This is our second year going down, and I can most certainly say that we will be going back. Our days consisted of going to a small mom-and-pop type diner for breakfast, loading the cooler with water, and then picking a hike to hit up. This time we hiked mostly in the Pisgah National Forest and while we did not hit the same elevation as last year, we still managed to double the first hike of the week on the second day and felt great once we reached the end. I also chose to make the hikes hard on myself by carrying my trusted GO-RUCK GR1 to carry our water, first aid kit, and a 30 lb. steel plate, because you should always choose the harder thing.

  • Gallery Image
  • Gallery Image
  • Gallery Image
  • Gallery Image
  • Gallery Image

While we weren’t at elevations like Pikes Peak in Colorado, we still felt the difference in the air between being in Cincinnati and being in the mountains. Maybe it was just the fact it was cleaner. When we crested a hill on the trail and stopped to take a quick break, we looked around and realized that after all the switchbacks we had just gone through, we looked over the valley we had just climbed out of and were at the tree tops of the valley and still nowhere near the top of the mountain. This got me to thinking about how I was working harder because I had a steel plate, walking too many lunches where I just sit for 30 minutes instead of walking and that is immediately connected to the ACFM calculations for an air compressor and just how a compressor will have to work harder to produce the same volume of air when elevated because the air is thinner. This is going to change the air density, which results in a lower atmospheric pressure due to higher altitude.

Altitude is just one of the factors that matters in the calculation to determine a compressor’s output at different locations. The other factors include relative humidity, which was way better in the mountains than here in Cincinnati, and the actual temperature, again better in Asheville than Cincinnati.

If you are wondering about the equations I am referencing, we’ve blogged about them many times and even have a Webinar that touches on the math and reasoning behind these different values. Check the equation below and the links above.

In case you were wondering, the post-Ruck/Hike hydration is always better after events, it also always helps to have a good partner in crime to enjoy all the experiences with you. Thankful for the ability to connect all these hobbies and my knowledge of compressed air on top of sharing it with others. If you want to discuss how to calculate some ACFM or SCFM consumption and outputs of your compressor or application, or if you want to talk about rucking, hiking, or any of your favorite trails, give me a call, chat, or tweet.

Brian Farno, MBA – CCASS
National Business Development Manager

BrianFarno@EXAIR.com
@EXAIR_BF

1 – Steve Martin & Edie Brickell – “When You Get To Asheville” – CBS, Retrieved from https://www.youtube.com/watch?v=4RzhTN9zW3w

Acronyms & Horses On the Hill

Published on by Brian FarnoLeave a comment

I’ve discussed how I volunteer in previous blogs. Sometimes it is during work hours, others, it is outside and on the weekends. The men’s group that I am part of at church has a smaller offshoot that goes out into our community and helps however possible. The name of our group is B4. It stands for Barbecue, Beer, Bible and Brotherhood. Four things most men appreciate, and again we call it B4 for short. My nerd-self argues it should be B 4. One of the projects we just wrapped up in our local community was for an organization called BLOC at their HOH facility. More acronyms. The HOH stands for Horses On the Hill and is a horse farm that is in an urban setting. This has working gardens that they sell fruit and vegetables to the community from, as well as a working horse farm where members learn how to care for the animals and ride, as well as work on some of their own items. While this blog isn’t about horse farms, it is about acronyms and how they can easily get thrown around when dealing with compressed air and air compressors. The picture is from our last day working there when we were wrapping up some trim work and watching a storm roll in. (Now tell me you’re from the MidWest with a single picture. )

Acronyms are something that comes with almost any field of study or professional position. Professionals everywhere love to use them and many even use them with redundant words. In my previous life, I took care of MSDS for the shop I worked in. What is MSDS? Material Safety Data Sheet is what it stands for, and any chemical should have one of these to accompany it in order to know how to handle the chemical safely. Even something like a window cleaner has one. It’s very easy to ask for an MSDS Sheet on a chemical, see that redundant word there? Times have changed, and now they are known as SDS, Safety Data Sheets. Still the same premise and still just as valuable when trying to be safe. When it comes to efficiency, though, acronyms used with redundant words are just not as efficient. You know that EXAIR is all about efficiency, and we deal with quite a few acronyms, so let’s talk about how we can ensure efficiency and lack of redundancy can be used when dealing with some of our acronyms.

CFM is the most basic one out of the bunch. It stands for Cubic Feet per Minute, and it is a unit of flow over time. This flow rate is generally used when dealing with gases, hence why we use it when talking about airflow, and really plays into many aspects of our products as well as the compressed air system in a facility. The metric equivalent is often M3/min. which, for an engineer-minded person, is easier to decipher, which doesn’t help a lot. It stands for Cubic Meters per Minute and is used by everyone else in the world outside the US. Both of these units of measure are thrown around a lot in the industry though, when a different unit is actually needed in order to meet the information needed.

CFM (M3/min.) is often stated when someone may actually be looking for SCFM, which is Standard Cubic Feet per Minute. This can also be a confusing unit, as the unit revolves around a reference point in order to be able to adapt it to your point of use conditions. We use a “Standard” condition that is accepted in the industry and that is 14.5 PSIA at 69° F and 0% RH. The Ideal Gas Law is used quite a bit to help determine how the RH, temperature, and pressure all affect the volume of the gas in question.

The least used version is ACFM, which is Actual Cubic Feet per Minute and is the ACTUAL flow rate under the conditions at the point of use. If we look at the horse farm mentioned above, on that day our relative humidity was through the roof while the temperature was low, so our volume would be impacted. While you believe this may be what you need more, generally it all has to be taken to standard conditions in order to calculate across different items anyway.

The newest of the acronyms is ICFM which is based around the Inlet Cubic Feet per Minute for the air’s conditions prior to entering the compressor at all. This, again, has to do with ACFM because it is at a specific pressure, relative humidity, and temperature.

The largest benefit to discussing consumption or flow rates with any Application Engineer at EXAIR is that we know the math behind converting each of these units of measure and can often get you the information you need right then and there as you talk with us. If you have some acronym fatigue from not knowing which to use, or you are trying to determine what the “Actual” output of your compressor is, contact one of our team members today.

Brian Farno, MBA – CCASS
National Business Development Manager

BrianFarno@EXAIR.com
@EXAIR_BF

BELIEVE

Published on by Brian FarnoLeave a comment

Okay, in case you haven’t been around the past year or two, and you have no clue where that simple word/statement comes from, then let me be the first to tell you that Ted Lasso is a great show, and you should check it out. So what does that have to do with EXAIR? Well, I like to think that sometimes the Application Engineers here are a lot like the coaching staff on the show. Sometimes we are strategic, we want to assert our experience and knowledge, and others, we are like Ted where we just ensure the thoughts and ideas you have already had.

That’s the fun part of being an Application Engineer here at EXAIR. I get to speak, chat, or email with both existing customers and potential new customers, resellers, and even catalog houses who all are trying to do one thing, improve a process or help someone out. Recently I was working with a manufacturing company trying to determine how fast they can cool a slab of steel with a Super Air Knife. Now, I by no means have a background in thermo like Russ Bowman, but he was busy preparing for our Spring Webinar to share some knowledge on Compressed Air System Storage. (If you haven’t checked a webinar out, most are available on our website in our knowledge base. ) So, I took the time to try and remember some of the tools I learned while at the University of Cincinnati. Thermodynamics was by far one of the hardest classes for me, The Algebra was always easy, I just always looked at the problems sideways I guess, and worried about too many variables. The truth of it is, if you keep it simple you can generally get somewhere close. so I took that approach. First I looked at what heat load would be generated by the steel slab.

\K.I.S.S. – Keep It Simple Stupid – Not always my forte!

I looked at the basic Heat Transfer equation – Q=c x m x ΔT where:

Q = Heat
c = specific heat capacity
m = mass
ΔT = Change in temperature

I was able to locate the mass of the carbon steel plate with 1/2″ thickness. So I calculated the mass of the sheet. Then looked up the specific heat of the same plate, and took the change in temperature from what the customer stated the plate started at and finished at.

This resulted in a heat load. Then to calculate how much cooling a Super Air Knife could provide I utilized another calculation that gives the BTU constant of a cubic foot of air moving and I did decrease the efficiency of the knife due to some assumptions on space and temperature constraints. The resulting factor was the customer would need 6 Super Air Knives to blow the sheet down as it travels 5 feet per minute on a 60′ long conveyor.

This again had several assumptions and I made that very clear to the customer. To convert the amount of air a Super Air Knife puts out and how much cooling it can use, I did make some clear assumptions on the temperature of their atmosphere and the amount of entrainment then I used a calculation that we adapt for Vortex Tubes and Cabinet coolers to determine what cooling load will be achieved if the air pressure or temperature is less than optimal on one of those products.

In the end, the customer received an educated estimation or calculated answer with listed assumptions, to solve their issue with cooling a steel slab before it is stacked together. I really only used two calculations and manipulated some variables to try and make sense of what I knew and what the customer needed. The best part is, this whole process is backed by our 30-day guarantee on stock products which our 48″ Super Air Knife is. So this customer can take my basic math, use my suggestions, place an order, and test it out in their facility for a factual performance test to then proceed with a permanent solution.

If you would like to discuss any point of use or potential application for compressed air in your facility, please contact an Application Engineer today!

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

So Many Holes

Published on by Brian FarnoLeave a comment

I remember the book and movie about a young teenager who gets sent to a prison/ work camp that all they do is dig holes. Yeah, there’s a much deeper story line there and that isn’t the point of this blog. The point is, that movie is all I thought of when I encountered this customer’s nozzle solution. Their ejector nozzle on a recycling conveyor was using too much air and was too noisy.

Upon receiving the nozzle to do a free EXAIR Efficiency Lab, we were absolutely amazed at the level of care taken to make something like this. The nozzle was purpose built and definitely got the job done, it also drained their compressed air system at times and made a lot of noise while it did the work. So what did this nozzle look like, now keep in mind, this was not the customer’s design, it was a solution from the machine manufacturer.

For an idea, the customer nozzle was a 3″ overall length, and had a total of 162 holes in it. There were two inlets for 3/8″ push to connect tubing. The holes were very cleanly drilled and we used a discharge through orifice chart to estimate the consumption before testing. Operating pressure were tested at 80 psig inlet pressure.

Discharge through an orifice table.

Our estimations were taken from the table above. We used a pin gauge to determine the hole size and it came close to a 1/32″ diameter. With the table below we selected the 1.34 CFM per hole and used a 0.61 multiplier as the holes appeared to have crisp edges.

Estimation Calculation

Then, we went to our lab and tested. The volumetric flow came out to be measured at 130.71 SCFM. This reassured us that our level of estimation is correct. We then measured the noise level at 95.3 dBA from 3′ away. Lastly, we tested what could replace the nozzle and came up with a 3″ Super Air Knife with a .004″ thick shim installed. To reach this solution we actually tested in a similar setup to the customer’s for functionality as they sent us some of their material.

Now for the savings, since this customer was focused on air savings, that’s what we focused on. The 3″ Super Air Knife w/ .004″ thick shim installed utilizes 5.8 SCFM per inch of knife length when operated at 80 psig inlet pressure. So the consumption looks like below

That’s an astounding amount of air saved for each nozzle that is replaced on this line. The line has 4 nozzles that they want to immediately change out. For a single nozzle, the savings and simple ROI looks like the table below.

Air Savings / Simple ROI

That’s right, they will save 115.02 SCFM per minute of operation. These units operate for seconds at a time so the amount of actual savings is still to be determined after a time study. In videos shared, there was not many seconds out of a minute where one of the four nozzles was not activated. Once the final operation per minute is received we can rework our calculations and see how many hours of line operation it will take to pay back each knife purchase.

If you have any point of use blowoff or part ejection and even have a “nice looking” blowoff in place, don’t hesitate to reach out. These are still very different from our Engineered Solutions. We will help you as much as we can and provide test data, pictures, and even video of testing when possible.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF