Duct Pressure Loss Calcs - HELP
Duct Pressure Loss Calcs - HELP
(OP)
Hi!
Am currently struggling with a calculating the static pressure loss thru a dust collection fitting ... none of the books I am referencing give a clear step-by-step procedure.
The fitting is a "Tapered Hood" type approx 8"x4" (32 sq. in.) inlet with a shallow transition to a 4" (12.6 sq. in.)diameter fitting. Airflow is 350CFM.
What is the most straight forward way of going about this?
Thanks in advance.
pkendall
Am currently struggling with a calculating the static pressure loss thru a dust collection fitting ... none of the books I am referencing give a clear step-by-step procedure.
The fitting is a "Tapered Hood" type approx 8"x4" (32 sq. in.) inlet with a shallow transition to a 4" (12.6 sq. in.)diameter fitting. Airflow is 350CFM.
What is the most straight forward way of going about this?
Thanks in advance.
pkendall





RE: Duct Pressure Loss Calcs - HELP
You are getting about 7.5"/100ft.
Get your hands on the ductsizer, a nice little program from Mcquay.
htt
Regards,
RE: Duct Pressure Loss Calcs - HELP
Will check out the McQuay software.
Have a nice day!
pkendall
RE: Duct Pressure Loss Calcs - HELP
"Industrial Ventilation", published by ACGIH, gives hood entry loss factors for various tapers. This publication is one of the best resources when it comes to designing dust collection systems.
Cheers,
CanuckMiner
RE: Duct Pressure Loss Calcs - HELP
RE: Duct Pressure Loss Calcs - HELP
I have the 22nd edition here...1995. Not too recent either, but it does have a Hood Entry Loss factors table/figure dated 1 - 95 (presumably, January 1995).
The table illustrates entry losses (in terms of velocity pressure) for round and rectangular ducts for various included angles, and has a graph illustrating the loss for a transition from rectangular to round.
Cheers,
CanuckMiner
RE: Duct Pressure Loss Calcs - HELP
SPh = VPd + (Fh x VPd) VPd = (4000fpm/4005)2 = 0.9975
SPh = 0.9975 + (0.45 x 0.9975)
SPh = 0.9975 + 0.448
SPh = 1.45" (361 Pa)
Thanks again everyone!
RE: Duct Pressure Loss Calcs - HELP
RE: Duct Pressure Loss Calcs - HELP