DUCT DIAMETER SELECTION 2

[seatrendgokhan]

I WOULD LIKE TO KNOW,IF THERE IS A FREE TECHINCAL DATA IN SOMEWHERE ABOUT HOW TO CALCULATE THE DUCT DIAMETER OR CROSS SECTIONAL AREA WHILE CONSIDERING THE FLOW RATE AND THE PRESSURE. FOR INSTANCE, IN A VESSEL WE HAVE 2 ELECTRIC DRIVEN FANS WHICH SUPPLY 92,000 cbm/h AIR @ ATMOSPHERIC CONDITION AND WE HAVE TO CALCULATE THE MAIN DUCT(s) TO THE MAIN ENGINE. WHAT SHOULD BE CONSIDERED ? THE OPENINGS ON THE DUCT ? THE EXHAUST OPENINGS FROM THE FUNNEL ? THANKS IN ADVANCE

GOKHAN

 

[stanlsimon]

It sounds like you need a certain volume flow rate of air, that is a given. Now you trying to design a duct to get the air to the engines. The size of the duct is determined by several factors.

1 Available Space
2 Pressure capability of the fan.

ASHRAE has published pressure drop tables for round duct.

Also the Trane Corporation has a nomographic device called a ductilator which will tell you the static pressure drop of the duct. I suggest you contact them. They can also help you size the fan if you need that also.

Sincerely,
Stan Simon

 

[imok2]

IT's free go here :

http://www.connel.com/freeware/airduct.shtml