Why does a flamethrower not explode?

  • Context: Undergrad 
  • Thread starter Thread starter lokifenrir96
  • Start date Start date
Click For Summary
SUMMARY

The discussion clarifies why flamethrowers do not explode despite the presence of flammable gas or liquid. The primary reason is that the fuel does not contain an oxidizer, which is necessary for combustion; thus, it cannot ignite until expelled. Additionally, the velocity of the fuel stream exceeds the rate at which flames can propagate, ensuring that the ignition point moves away from the operator, preventing backfire into the fuel container.

PREREQUISITES
  • Understanding of combustion principles
  • Knowledge of oxidizers and their role in fire
  • Familiarity with fluid dynamics, particularly in high-pressure systems
  • Basic knowledge of flamethrower mechanics
NEXT STEPS
  • Research the role of oxidizers in combustion reactions
  • Study fluid dynamics related to high-pressure gas flows
  • Explore safety mechanisms in flamethrower design
  • Learn about the physics of flame propagation
USEFUL FOR

This discussion is beneficial for safety engineers, pyrotechnics enthusiasts, and individuals interested in the mechanics of combustion and fluid dynamics.

lokifenrir96
Messages
21
Reaction score
0
To be more specific, why is it that when the flammable gas or liquid is pumped through the barrel and ignited at the end of the barrel, the flame does not spread backwards along the stream of liquid/gas into the fuel container and cause an explosion?

Is it simply because of the high pressure at which the fuel is pumped out? Or is there another reason, or a safety mechanism to prevent this from occurring?

Thanks!
 
Science news on Phys.org
Two factors. Most important is that fuel in flame thrower doesn't contain oxidizer. It needs oxygen in air to burn. So it can't burn until it is expelled.

Second is that the stream typically travels faster than flame can propagate along the stream. So the ignition point is actually carried away from the operator.
 
Well-explained, thanks!
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
Replies
2
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 8 ·
Replies
8
Views
9K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 3 ·
Replies
3
Views
94K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K