Results 1 to 7 of 7
Thread: Fan flow
-
16-02-2006, 11:41 AM #1
Fan flow
Hi guys.
I was running a few tests today and was just wondering what your speculations would be
Constants. Fan motor, pwr supply, air baffle, refrigerated space, ambient, test equiptment.
I start with a 20inch fan and matching cowl and measure Watts, Amps, M3/Hr and Rpm.
What will happen to these values if I increse firstly the blade and cowl diameter by 1 inch?
Then increase the pitch.
And decrease the pitch.
I have results but would like your speculation.
-
28-02-2006, 10:00 AM #2
Re: Fan flow
If you increase the diameter of the fan, the result depends on fan motor characteristics. If the motor didn't work on its limits, the m3/h, watts and amps will increase. If the motor had optimal load before increasing the fan diameter, the m3/h stay constant or decrease, the Watts and Amps stay constant or increase.
-
28-02-2006, 11:10 AM #3
Re: Fan flow
Originally Posted by hybridjunction
speaking from a speculative point of view, i think your fan may speed up or slow down. there is also the possibility that the volume of air moved by the fan may increase or decrease. further speculation leads me to believe that if you reverse the direction of the motor it may blow air in the other direction to the first direction in which it was directed.Takes a licking, keeps on ticking.
-
01-03-2006, 09:28 PM #4
Re: Fan flow
It's simple , using the same fan but changing a parameter and see how this affects the other parameters, can be done by using the "Rateau" simulation (similitude) formulas (if you consider that the air density is unchangable between the inlet and the outlet of the fan).
If you need more information please let me knowEngineering, sciences, math, physics and my brain will generate "not responding " soon
-
05-03-2006, 01:04 PM #5
Re: Fan flow
Originally Posted by slingblade
That is very speculative slingbade thanks.
-
05-03-2006, 01:08 PM #6
Re: Fan flow
Originally Posted by botrous
If you could elaborate, it would be appreciated.
I'm new to Refrigeration, yet to do second block of training. So These formulas would give great insight.
Regards
Hybridjunction
-
05-03-2006, 01:14 PM #7
Re: Fan flow
Anyway, It was found that increasing dia by 1 inch gave less air flow, slower revs, same amps and higher wattage; but when the pitch was increased 8 deg, wattage acually was lower than the former and air flow was greater.
When it came to a load test though, the larger fan with greater pitch failed.
It was put down to the air distribution characteristics.
?????????????????????????????????????????
Similar Threads
-
flow switch connection
By afeef in forum The Trail of TearsReplies: 18Last Post: 23-12-2009, 06:55 PM -
capillary tubes and mass flow when fed with liquid/gas
By DaBit in forum FundamentalsReplies: 15Last Post: 24-10-2002, 06:52 PM -
Not enough air flow
By coolsights2000 in forum Technical DiscussionsReplies: 1Last Post: 22-07-2002, 06:35 PM -
Accidental Release Flow Rates
By mbeychok in forum IndustrialReplies: 0Last Post: 20-11-2001, 12:53 AM -
Accidental Release Flow Rates
By mbeychok in forum Tools and CalculatorsReplies: 0Last Post: 20-11-2001, 12:45 AM