Can Gas Flow Backwards and Reach Inside a Cylinder in an LPG System?

  • Thread starter Thread starter sgvaibhav
  • Start date Start date
  • Tags Tags
    Flow
AI Thread Summary
In an LPG system with a rubber pipe connected to a cylinder, the flame at the open end of the pipe will not travel back into the cylinder due to the lack of oxygen inside the tank and hose. The high velocity of gas flow also prevents flame propagation towards the cylinder. Although the flame can burn the rubber hose, it will not cause a safety hazard by reaching the cylinder. The pressure regulator is set at 1.2 bar, but with the pipe open to the atmosphere, the gauge reads zero. Overall, the setup is considered safe as the flame cannot backtrack to the gas cylinder.
sgvaibhav
Messages
65
Reaction score
0
Consider this case.

An LPG cylinder is used to provide LPG to a rubber pipe (3/8" diameter).
If a regulator is attached to the cylinder, and the rubber pipe is just left open on the other side to let gas out, and a match is kept at the open end.
Will the flame that is created at the open end of rubber pipe move all the way inside the rubber pipe and reached inside the cylinder? Or will the gas flowing at high velocity just not let the flame move back inside?
The pressure regulator is set at 1.2 bar gage pressure, however the pressure gauge after the valve shows 0 reading, since the pipe is just left open to the atmosphere.

The rubber pipe is about 2m long.

A gate valve is used to let the gas out in somewhat controlled quantities.

Schematic attached - i primarily wanted to know if the flame will move backwards and reach the cylinder or not (to know the safety issues)
 

Attachments

  • schmatic.png
    schmatic.png
    32.6 KB · Views: 499
Engineering news on Phys.org
As far as I know, it's the lack of oxygen in the tank and hose that prevents flame propagation. Don't take my word for it, though.
 
It will not travel back inside the rubber hose. However, it could burn the rubber hose off and continue to make it shorter and shorter...
 
oh that's okay :P...

all i didnt want is the flame going back towards the gas cylinder and blasting the cylinder!
 
How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...
Back
Top