nozzle angle when you increase pressure

burnerman_2

well the droplets decrease in size but the angle stays the same patterern royboy

marcel l greene

nozzle angles

what happens to the angle of a nozzle when you increase pressure at the pump?

J.C.A._3

I disagree royboy.

When the pressure increases, the spray pattern will follow suit. If an 80° nozzle is speced. at 100psi, why would almost all manufacturers suggest going to either a 70 or even a 60° nozzle when increasing the pressure at the fuel unit?

Spread that fuel out at a higher pressure if YOU'D like to. Me, I'll follow what the makers say and be home having dinner while you go out on fouled head and coked retention ring calls. Chris

rjm

huh

I thought with an increase in pressure the fire gets elongated, skewed from the original angle. ex. 80 degree becomes more like a 60 degree at a higher pressure.

Steve_35

Not true according to Delavan, JMC

http://www.delavaninc.com/pdf/Fuel_Nozzles_for_Burners.PDF

From page 4, "After a true divergent spray is established, any increase in the pressure does not change the basic spray angle. In the above photographs it will be noted that the spray angle
measured at the orifice is the same at 300 psi as it is at 10 psi."

An interesting read.

Unknown

Agreed...

Good read

Mitch_4

They spec a different

nozzle (as told to me) because, while the angle does not change, the distance it is thrown will. The angle change is require to prevent the flame impingement

jp_2

pressure increase, angle increase

i would tend to agree with that too. higher pressure will create higher turbulence which will fan out the spray pattern more.

BUT that might not really happen with relatively small pressure changes. happens but not really noticeable.

Steve_35

Check the article linked above

It's by Delavan's engineers accompanied with photos of the same nozzle under varying pressures. According to them and the pictures, there's no significant angle change with pressure change "after a true divergent spray is established". The information shows no angle change from 10-300psi.

Pretty interesting article that I'd recommend reading.

[Deleted User]

Higher fuel

unit pressures will not change the pattern close to the nozzle. However, the angle of spray further away from the nozzle starts to pull in. From NORA Tech Guide Chapter 5 Page 83.

Many contend that results in a shorter flame.

Unknown

Yes,

The Delavan article also mentions differences in pattern at higher pressures as the fuel spray gets farther away from the nozzle and the droplets begin to lose their momentum.