Tag: engineering

Tools Of The Trade: The Rotameter

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EXAIR’s Free Efficiency Lab

One of the free services we offer to customers here at EXAIR is our Efficiency Lab. In case you are not familiar here is a brief synopsis. Speak with an Application Engineer about your existing compressed air blowoff/point of use product and that you would like to know how much air it consumes. Fill out the brief survey and send the product you use in to our facility. Let us perform tests on calibrated test equipment to determine the force, flow, and noise level. We will then issue you a report that states what the EXAIR model would best be suited (if applicable) as well as how much compressed air you will be able to save. Order the recommendation and start saving money.

To do these evaluations, we have to have calibrated equipment that is reliable and capable of handling vast range of products we may receive in. For this, we could use a Digital Flowmeter, in some cases that is what has to be done due to large flow rates. For the majority of these though we go old school. We utilize a piece of equipment called a rotameter.

A rotameter pairs nicely with a calibrated pressure gauge as well.
The float can be seen with graduated marks for readings. The taper of the chamber is not easily seen with the naked eye.

This is a device that is designed to measure the flow rate of a fluid within a closed tube. The inside diameter of the tube is varied which causes the float within the meter to raise or lower.  They are calibrated for a specific gas at a given pressure and temperature, most are calibrated for atmospheric conditions, 14.7 psi (1.014 Bar). The meter must be mounted vertically and this is not always best suited for industrial environments.

When testing products the compressed air within the meter is pressurized which means we have to correct the reading for the given pressure, if the temperature is outside of the calibration temp then we must also perform that correction. We do this using a table provided by the manufacturer of the meter or by using the calculations shown to get exact values that may be in between the pressures in the table.

Pressure Correction Table

 

This will allow us to then multiply the Correction Factor by the meter reading and calculate our corrected flow for the point of use device at a given operating pressure and temperature.

Temperature correction table

Knowing where the values that are measured and calculated come from add validity to the reports and understanding all of the variables that go into reading like this helps to better validate the cost savings that can be seen.

In a pinch, for a field estimation, we can also use these Correction Factors and determine an approximate consumption rate of a device that has been measured at a pressure such as our cataloged 80 psig (5.5 Bar). This can often be done on the fly to help determine the flowrates currently on a system. This can be helpful when troubleshooting, giving estimated simple ROIs, and help justify results and reasons for future purchases of engineered solutions.

If you want to discuss the Efficiency Lab or any of the math behind our calculations, contact any Application Engineer, we can all help out.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Battling Heat Transfer

Published on by Brian FarnoLeave a comment

If you haven’t read many of my blogs then this may be a surprise. I like to use videos to embellish the typed word. I find this is an effective way and often gives better understanding when available.  Today’s discussion is nothing short of benefiting from a video.

We’ve shared before that there are three types of heat transfer, more if you go into sub-categories of each. These types are Convection,  Conduction, and Radiation. If you want a better understanding of those, feel free to check out Russ Bowman’s blog here.  Thanks to the US Navy’s nuclear power school, he is definitely one of the heat transfer experts at EXAIR.  If you are a visual learner like myself, check out the video below.

The Application Engineering team at EXAIR handles any call where customers may not understand what EXAIR product is best suited for their application. A good number of these applications revolve around cooling down a part, area, electrical cabinet, or preventing heat from entering those areas.  Understanding what type of heat transfer we are going to be combating is often helpful for us to best select an engineered solution for your needs.

Other variables that are helpful to know are:

Part / cabinet dimensions
Material of construction
External ambient temperature
If a cabinet, the internal air temperature
Maximum ambient temperature
Desired temperature
Amount of time available
Area to work with / installation area

Understanding several of these variables will often help us determine if we need to look more towards a spot cooler that is based on the vortex tube or if we can use the entrained ambient air to help mitigate the heat transfer you are seeing.

If you would like to discuss cooling your part, electrical cabinet, or processes, EXAIR is available. Or if you want help trying to determine the best product for your process contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Video Source: Heat Transfer: Crash Course Engineering #14, Aug 23, 2018 – via CrashCourse – Youtube – https://www.youtube.com/watch?v=YK7G6l_K6sA

Back To The Basics: Process Improvement Basics

Published on by Brian FarnoLeave a comment

We understand that it is more important than ever to realize savings within manufacturing processes. EXAIR can reduce compressed air consumption and provide simple ROI in a matter of weeks in MANY cases.

In the hustle and bustle of the daily grind wherever you are, there are certain processes that become muscle memory for you and certain processes that just work and don’t need any attention. Whether it be a login process for your computer network, the number of steps it takes to fill your coffee cup, or the compressed air applications in your facility.

You know what I am talking about, these items begin to get glanced over and often become overlooked. When going through process improvements or troubleshooting, it is easy to overlook processes which are not causing trouble or that have become “acceptable” because they are producing. EXAIR firmly believes compressed air applications are ripe for improvement, and our product lines are built to replace inefficient compressed air products with engineered and efficient solutions.

When evaluating a process for improvement creating a baseline is the necessary start. With this, we can then start to draw a realistic target of where the process needs to be in order to be optimized and document the changes from our starting baseline.

Much like the 6 Steps to Compressed Air Optimization, which starts with measuring compressed air consumption to provide a baseline.  Sometimes, this may require the installation of a Digital Flowmeter, others it may include taking advantage of our Efficiency Lab service for us to get a baseline of what air consumption and other key performance indicators are for your application.

Looking to “go green?” We can help.

Once we have the baseline and a target, we can then begin to design an improvement process. Whether this is implementing better controls for the air, such as pressure regulators, or implementing controllers such as the Electronic Flow Control, it may even be simply installing an engineered solution.  Once an improvement has been implemented we can then go on to the next testing phase to again gather data to see how much air was saved from the baseline.

EXAIR’s Free Efficiency Lab

Once the performance of the new process is determined then we can take the new cost of ownership numbers and give a simple return on investment back to determine what the actual savings by implementing these process improvements have amounted to.

The below example is from a customer who had already improved their static elimination application by using our Super Ion Air Knife instead of a homemade pipe with drilled holes. They further optimized the application with our Electronic Flow Control.

If you would like to talk through methods for process improvement or how we can help you determine these costs, please reach out.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Pressure Gauges – Why You Need Them & How They Work

Published on by Brian FarnoLeave a comment

There is hardly a day I work that I am not talking about the importance of properly installed pressure gauges.  These small devices can often get overlooked or thought of as not necessary on an installation.  When troubleshooting or evaluating the compressed air consumption of an application, this is one of the first items I look for in the installation.

As Russ Bowman shows in the above video discussing proper piping sizes, you can see the importance of properly placed pressure gauges.  This shows the worst-case scenario where the pressure drop due to improper line sizes gives the false sense to the operator that they are achieving full line pressure when in fact they are not.  In order to accurately measure consumption rates, pressure AT THE INLET (within a few feet) to any compressed air product is necessary, rather than upstream at a point where there may be restrictions or pressure drops between the inlet and the gauge. So how exactly do these analog gauges measure the pressure of the compressed air at the installed locations?

Pressure Gauge Model 9011

The video below shows a great example of pressure increasing and decreasing moving the Bourdon tube that is connected to the indicating needle.  The description that follows goes more in-depth with how these internals function.

Most mechanical gauges utilize a Bourdon-tube. The Bourdon-tube was invented in 1849 by a French watchmaker, Eugéne Bourdon.  The movable end of the Bourdon-tube is connected via a pivot pin/link to the lever.  The lever is an extension of the sector gear and movement of the lever results in rotation of the sector gear. The sector gear meshes with spur gear (not visible) on the indicator needle axle which passes through the gauge face and holds the indicator needle.  Lastly, there is a small hairspring in place to put tension on the gear system to eliminate gear lash and hysteresis.

When the pressure inside the Bourdon-tube increases, the Bourdon-tube will straighten. The amount of straightening that occurs is proportional to the pressure inside the tube. As the tube straightens, the movement engages the link, lever, and gear system that results in the indicator needle sweeping across the gauge.

If you would like to discuss pressure gauges, the best locations to install them, or how much compressed air an application is using at a given pressure, give us a call, email, or chat.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF