A Perfect Fit for Primary Metal Manufacturing

Primary metal manufacturing and processing plants tend to have a variety of applications using compressed air, some of which can be quite large.  Our Finnish distributor found just such an application, using a high volume of compressed air under unsafe conditions.

20151111_122132

Homemade air gun at a metal manufacturing plant in Finland

In the photo above you can see a homemade air gun used to provide a high force blow off.  This unit has a welded cone on the end of a metal pipe using a ¼ turn ball valve to control the compressed air.  When the ball valve is turned the airflow remains constant until the operator returns the valve to the closed position.  This means that if the operator were to let go of the unit for any reason, the air gun would continue to blow, creating a safety hazard.

In addition to this concern, the welded cone at the end of the pipe provides no protection for high dead end pressures, creating a potential source of an air embolism if contacting human skin.  This can lead to difficulty breathing, chest pain, low blood pressure, or even a stroke (Source: MedScape; Venous Air Embolism; Updated December 8th, 2015).

The end user had accepted the risks associated with this homemade device because they were unaware of anything in the market capable of meeting the volume and force necessary to meet their application needs.  That is, until they were shown the EXAIR Super Blast Safety Air Gun model 1218.

Feeding the compressed air through an automatically closing ball valve, the 1218 removed the threat of unwanted flow from such a high force air gun.  The model 1218 also provides more than enough force and flow – the existing setup uses a 1-1/4” diameter orifice with a flow rate of 1986 SCFM (56,233 SLPM) with an unknown entrainment ratio; the 1218 has a flow rate of 460 SCFM (13,026 SLPM) with an entrainment ratio of 25:1, making the total directed flow equal to 11,500 SCFM (325,650 SLPM)!  This means the application can produce better or equal performance at a fraction of the compressed air consumption, thanks to the engineered design of EXAIR nozzles.  (See below for operational cost comparison.)

By converting to an EXAIR Super Blast Safety Air Gun this customer was able to add safety, increase performance, and lower operating costs.  If you have an application you think could benefit from better safety, performance, or operating cost, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

 

Compressed air costs are calculated as follows:

Previous setup:

1,986 SCFM compressed air consumption.  At a cost of $0.25/1000 SCF this equates to:

1,986 * ($0.25/1000) = $0.4965 for every minute of use

EXAIR model 1218:

460 SCFM compressed air consumption.  At the same cost of $0.25/1000 SCF this equates to:

460 * ($0.25/1000) = $0.115 for every minute of use

When comparing the two, the EXAIR model 1218 will provide an operational cost savings of almost 77%!

And, if you’re wondering how we determined the airflow through the existing setup, we used the charts below.

air calcs

Air calcs for the flow through a 1-1/4″ orifice

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