How to Size a Receiver Tank and Improve your Compressed Air System

Receiver Tank: Model 9500-60

My colleague, Lee Evans, wrote a blog about calculating the size of primary receiver tanks within a compressed air system.  (You can read it here: Receiver Tank Principle and Calculations).  I would like to expand a bit more about secondary receiver tanks.  They can be strategically placed throughout the plant to improve your compressed air system.  The primary receiver tanks help to protect the supply side when demands are high, and the secondary receiver tanks help systems on the demand side to optimize performance.

Circuit Board

I like to compare the pneumatic system to an electrical system.  The receiver tanks are like capacitors.  They store energy produced by an air compressor like a capacitor stores energy from an electrical source.  If you have ever seen an electrical circuit board, you notice many capacitors with different sizes throughout the circuit board (reference photo above).  The reason is to have a ready source of energy to increase efficiency and speed for the ebbs and flows of electrical signals.  The same can be said for the secondary receiver tanks in a pneumatic system.

To tie this to a compressed air system, if you have an area that requires a high volume of compressed air intermittently, a secondary receiver tank would benefit this system.  There are valves, cylinders, actuators, and pneumatic controls which turn on and off.  And in most situations, very quickly.  To maximize speed and efficiency, it is important to have a ready source of air nearby to supply the necessary amount quickly.

For calculating a minimum volume size for your secondary receiver tank, we can use Equation 1 below.  It is the same as sizing a primary receiver tank, but the scalars are slightly different.  The secondary receivers are located to run a certain machine or area.  The supply line to this tank will typically come from a header pipe that supplies the entire facility.  Generally, it is smaller in diameter; so, we have to look at the air supply that it can feed into the tank.  For example, a 1” NPT Schedule 40 Pipe at 100 PSIG can supply a maximum of 150 SCFM of air flow.  This value is used for Cap below.  C is the largest air demand for the machine or targeted area that will be using the tank.  If the C value is less than the Cap value, then a secondary tank is not needed.  If the Cap is below the C value, then we can calculate the smallest volume that would be needed.  The other value is the minimum tank pressure.  In most cases, a regulator is used to set the air pressure for the machine or area.  If the specification is 80 PSIG, then you would use this value as P2.  P1 is the header pressure that will be coming into the secondary tank.  With this collection of information, you can use Equation 1 to calculate the minimum tank volume.  So, any larger volume would fit the requirement as a secondary receiver tank.

Secondary Receiver tank capacity formula (Equation 1)

V = T * (C – Cap) * (Pa) / (P1-P2)

Where:

V – Volume of receiver tank (cubic feet)

T – Time interval (minutes)

C – Air demand for system (cubic feet per minute)

Cap – Supply value of inlet pipe (cubic feet per minute)

Pa – Absolute atmospheric pressure (PSIA)

P1 – Header Pressure (PSIG)

P2 – Regulated Pressure (PSIG)

If you find that your pneumatic devices are lacking in performance because the air pressure seems to drop during operation, you may need to add a secondary receiver to that system.  For any intermittent design, the tank can store that energy like a capacitor to optimize the performance.  EXAIR stocks 60 Gallon tanks, model 9500-60 to add to those specific locations, If you have any questions about using a receiver tank in your application, primary or secondary, you can contact an EXAIR Application Engineer.  We can restore that efficiency and speed back into your application.

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

 

Photo: Circuit Board courtesy from T_Tide under Pixabay License

Video Blog: EXAIR’s Efficiency Lab

If you’d like to know how efficient (or not,) quiet (or not,) and effective (or not) your current compressed air devices are, the EXAIR Efficiency Lab can help.  For more details, we hope you’ll enjoy this short video.

If you’d like to talk about getting the most out of your compressed air system, we’d love to hear from you.

Russ Bowman
Application Engineer
EXAIR Corporation
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Super Ion Air Knife Removes Foil Dots In Lid Cutting Operation

I recently received an inquiry from a food manufacturer about a packaging line they were having issues with.  The plant fills continuous rows of thermo-formed cups which is then sealed with a single foil lid. Once sealed, a machine cuts the row to separate the cups, which creates small scrap pieces of foil. After the cutting operation, they try to collect as much of the waste trim as possible but some small pieces of foil, they call “dots”, cling to the surface of the cup and cutter due to static charge.  The company installed a vacuum collection hood in this area, to try and help keep the foil pieces or any dust from falling onto the cup during the process. While this did help somewhat, some dots would remain and eventually fall off further down the line, making small piles that needed to be manually cleaned to avoid potential jams, which slowed down their production cycle.

The cups are filled and separated on a 44″ wide, mesh-screen conveyor with individual lanes to process multiple rows of cups. After being cut, the cups are moved to the inspection area and then packaged for shipment.  I recommended they mount a 48″ Super Ion Air Knife above and below the cups and direct the airflow to the end where the vacuum collection hood is located. The idea is, as the ions eliminate the charge, the small foil dots will release and the laminar airflow would keep the parts moving toward the vacuum hood, thus removing all foil trim and preventing any piling of trim further down the production line.

The Super Ion Air Knife produces a sheet of ionized air capable of dissipating 5 kV in just a fraction of a second!

EXAIR offers a wide selection of Static Eliminators for use in a variety of industrial processes. If you are experiencing static concerns in a particular area or to discuss a specific process, please contact an application engineer for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Stainless Steel Line Vac Conveys Egg Shells from Harvester to Waste Bin

IMG_0787

Our customer has a process where they de-cap eggs which are used in a variety of processes ranging from large scale bakery uses to medical uses for developing vaccines. The problem is they are left with a reasonable amount of egg shell waste that needs to be cleaned up after each cycle in the de-capping process. The previous method relied simply on friction and gravity to get the egg shell to go into the direction the customer wanted.

The problem with this method is that reliability was quite low. Egg shell would remain inside the egg, inside the tooling and pretty much everywhere around the de-capping process. The customer wanted to clean things up in the process a bit and increase the reliability that the shells go where they want them to which is a waste container about 5 meters away from the de-capper. The rate of shell flow was about 20 kilos per hour.

The customer made a search on the Internet for Air Vacuum conveyors and found EXAIR Corporation. After a short discussion to find out the specifics concerning rate of flow, distance, density of the product and available air pressure, we were able to make a suitable recommendation.

We ended up recommending EXAIR Model 6963 (1-1/2” Stainless Steel Line Vac kit). Having the full kit available allows the customer to install the Line Vac using included bracket for mounting as well as the air filter/separator and compressed air regulator with gauge to allow for accurate tuning of the air pressure to get just the right amount of suction from the Line Vac unit.

The customer purchased the recommended kit and installed on their machine. They have claimed the reliability has gotten to the point where the problem has nearly gone away. They still had some issues with the blades used, which they intend to sort out as a next step in their process of continuous improvement.

Neal Raker
Application Engineer
nealraker@exair.com

Continuous Improvement

I’m sure I have blogged about similar topics before but I’m going ahead with this anyway.   Have you ever bought something and after using it a few times say to yourself, I really wish they would have done this or I wish this had this feature.  I do that quite often, more often that my wife really cares for.  Normally it ends up with me being in the garage or the basement working on whatever it is for several hours and possibly even breaking whatever it was I was working on.  Well, I don’t just do that at home.

Two of our newest Industrial Housekeeping products were created from our own employees using them and seeing something that could make it better.   The easiest to see this with is our Chip Trapper System.

RDVFamily_300pxCT

Our Reversible Drum Vac Systems were around for a couple decades when someone decided to figure out a (patented) way to filter all the chips and solids out of the coolant we were processing.  So now, instead of just sucking the coolant out, we are able to filter the coolant and reuse it up to four times longer in our machines.

It is continuous improvements and being willing to listen to recommendations that make things like the Chip Trapper possible.  If you have one of our products and see a better idea, feel free to let us know, it may even be something that we could do on a custom basis for you.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF