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Gas + Air = Fire

At the ship illutron, I have been doing some experiments with mixing air and propane using the venturi effect - like a bunsen burner. 
This little guide should show you one way to make it work - What size nozzle to use etc.

Venturi / Bunsen Burner - How to mix propane & air for perfect burning

Basic principle of a venturi to mix air & propane (gas): 


  • Gas flows out of a small nozzle ( ~ Ø 0.83 mm )  
  • Small nozzle => High flow velocity (Makes sense)
  • High flow velocity => Pressure drop (Makes sense, if you do the math 
    • Tip: Think of energy conservation - Higher speed = Higher Kinetic energy. Lower Potential energy = Lower pressure )
  • Pressure drop => Sucks in air
To get the mix right, and the burn good, there is a close relationship between nozzle hole size and pipe size. 
I will go into details about this in another post. 

Nozzle size & Mixing Tube sizes that work - simple and quick

Nozzles come in different sizes

Materials

  • Propane nozzle. Diameter 0.83 mm. 
    • Can be found inside the burner of gas stoves 
  • Mixing tube. Diameter: 15 mm. ( 1/2 inch pipe ) Length: 4-5 cm is fine 
  • Fittings - to fit it all together  
  • LPG (Commercial gas like propane)
  • Gas Pressure Regulator (Regulating to +30 mBar - Standard kitchen pressure) 

Notice how moving the mixing tube influences the flame. An air gap gives a better, hotter flame


Notice how disrupting the gas flow with your finger, will make the flame bite you... 
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