Metal finishing Q&As since 1989

-----

Fan Curves Needed

We are looking for fan curves for Beverly Pacific FRP scrubber fans. We would like to increase the speed, however we do not want to exceed the fans tip speed. The Model number is "PS30HC", Serial number "F-566", we also have a CB-49 unit of the same manufacture. They are currently performing at 36,510 CFM @ 5.89" TP with a fan RPM of 956. If you can point me in the right direction it would be greatly appreciate.

We are a Test and Balance firm and do not install or sell equipment, we are looking for the above information to help service our customers. Terry J. Flood

Terry J, Flood
Q.C. Analytical Services - Peoria, Arizona
2000

---

2000

Terry, you should be able to get the data you want from that Beverly Pacific fan Company.

Anyhow, the data you gave lacked the all important wheel diameter. 'tis a question of tip speed that determines the max. safe rpm, eh? Further, wide wheels may give the CFM but will do poorly on SP.

Using the old COBRA data,(COBRA was the trade name for the Grandview Industries Div. of Noranda that ceased business in l982 but whose fan designer, Gert Jungblut, still makes this super design at Alfa Plastics in Brampton, Ontario)for that airflow of 38,000 odd CFM one could have used a 78" dia or, my choice, an 86" dia wheel. Both capable of 8" SP at around max. l0,000 fpm. Mind you, a heavier constructed COBRA wheel with a slightly different blade curve would go to over l6" SP @ l4,000 fpm tip speed. ALLANCO in the Vancouver area, who were given this design some years ago by friendly Noranda, say that they have gone way past l6" SP.

Not knowing the design, not knowing the 'integrity' of manufacture, not knowing the current wheel 'condition', I suggest you be careful and not go over a tip speed of 8,000 fpm.

I further presume that it is after a scrubber which probably counts for most of the SP draw. Let's just hope that the scrubber does a good job of protecting the fan !

I hope this might be of some help. Cheers !

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

---

Dear Sirs,

I greet you courteously to make you a question: Because I'd like testing performance in some centrifugal fans, I'm looking for formulas relating: Cap (CFM), outlet velocity (FPM), static pressure, velocity RPM, BHP, etc. I'm worry because I can't find any information about that, so I'd be very grateful if you kindly gave me any reference for that.

Thanks in advance,

Zenith Vivas
- WNY, New Jersey
2002