Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 42 users online :: 4 registered, 0 hidden and 38 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Exabot [Bot], Google [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Pnematic Venting Idea

Post questions and info about combustion (flammable vapor) powered cannons here. This includes discussion about fuels, ratios, ignition systems, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Pnematic Venting Idea

Unread postAuthor: jjjd » Fri Mar 16, 2007 11:28 am

I wave a new idea to vent combustions without having to open an end cap and such, have a smaller chamber next to your combustion chamber and have it hooked up to an oxygen canister. after your shot open the ball valve from the smaller chamber and the pressure will push out the exhaust. this will also provide a better burn rate for the next shot.

I would still have a chamber fan inside but make sure it is behind the opening for the oxygen chamber.

Do you guys think this would work out good, or be unsafe from the oxygen mix with propane? I am using all sch 40 parts for this, all 250psi +.

Thanks, Andrew
  • 0

User avatar
jjjd
Staff Sergeant
Staff Sergeant
 
Posts: 117
Joined: Wed Nov 29, 2006 12:39 pm
Reputation: 0

Unread postAuthor: spudkilla » Fri Mar 16, 2007 11:32 am

Why not just a simple canister/tank of compressed air instead of oxygen.
  • 0

User avatar
spudkilla
Master Sergeant
Master Sergeant
 
Posts: 163
Joined: Sun Jan 21, 2007 10:33 am
Reputation: 0

Unread postAuthor: risto » Fri Mar 16, 2007 12:03 pm

jjjd! ah! i had an idea so similar to this but i was keeping it secret so i could use it for the contest!

grrr!

haha, well, i have plans drawn up on how i was going to get it to work and all and from what i can tell, it will work, but i'm going to do a few experiments tomorrow to see if it actually does.

haha, great minds think alike, no?

EDIT: i just finished reading all your post:

DO NOT USE PURE OXYGEN! THAT IS DISASTROUS! My plan was to use a compressed air tank. NEVER- UNDER ANY CIRCUMSTANCE -HAVE PURE OXYGEN IN A COMBUSTION CHAMBER!!!! (if you value your life at least)
  • 0

User avatar
risto
Sergeant First Class
Sergeant First Class
 
Posts: 144
Joined: Sat Feb 24, 2007 8:07 pm
Location: Citrus County, FL, USA
Reputation: 0

Unread postAuthor: jjjd » Fri Mar 16, 2007 12:17 pm

I wanted to use oxygen for the simplicity of having it with me in a backpack or strapped to the gun, i just don't want to have to use a bike pump or air compressor all the time. I was thinking of taking an old propane canister and refiling it with air in order to vent, but I am not sure if attaching an air compressor to the valve head would fill it. what do you think?
  • 0

User avatar
jjjd
Staff Sergeant
Staff Sergeant
 
Posts: 117
Joined: Wed Nov 29, 2006 12:39 pm
Reputation: 0

Unread postAuthor: The_Engineer » Fri Mar 16, 2007 12:53 pm

the problem That I see is that in order to push out all the combustion by-products you will have to add a lot of oxygen after each shot. If you plan on adding enough propane to have a complete reaction be carful the force will be about five times bidder and much faster. The other alternative is just refill the chamber with some oxygen to regain the oxygen to inert gas ratio previously present in air. If you do that you could have normal power shots.
  • 0


The_Engineer
Private
Private
 
Posts: 5
Joined: Thu Mar 15, 2007 2:37 pm
Reputation: 0

Unread postAuthor: The_Engineer » Fri Mar 16, 2007 12:56 pm

Also I am not sure about refilling a propane tank with compressed air. Propane is a liquid when compressed and thus does not require nearly as much pressure as you would need with air.
  • 0


The_Engineer
Private
Private
 
Posts: 5
Joined: Thu Mar 15, 2007 2:37 pm
Reputation: 0

Unread postAuthor: The_Engineer » Fri Mar 16, 2007 12:59 pm

PS I looked it up and vapor pressure of propane is up to 170 psi when at 100 deg F. So I guess\ you could refill a propane tank, just be carful they ar not designed for that use.
  • 0


The_Engineer
Private
Private
 
Posts: 5
Joined: Thu Mar 15, 2007 2:37 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: A-98 » Fri Mar 16, 2007 1:13 pm

arg! theres an edit button you know....(im not angry, just annoyed...hard to tell the difference when in text)
  • 0

Last edited by A-98 on Fri Mar 16, 2007 5:27 pm, edited 1 time in total.
There are rules, and then there are hundred dollar bills.
User avatar
A-98
Brigadier General
Brigadier General
 
Posts: 921
Joined: Thu Apr 27, 2006 7:41 pm
Location: Santa Barbara, CA
Reputation: 0

Unread postAuthor: MrCrowley » Fri Mar 16, 2007 5:04 pm

Why have the second chamber at all? Apart from the oxygen boost for next shot. Just use a big ball valve like 1.5" to vent the chamber and turn your chamber fan on.
  • 0

User avatar
MrCrowley
Moderator
Moderator
 
Posts: 10207
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Country: New Zealand (nz)
Reputation: 4

Unread postAuthor: benstern » Fri Mar 16, 2007 7:07 pm

Extra oxygen won't friggen matter if you have a fuel meter, you will already be attaining the best possible mix!!!!!! :evil: :evil:

pure oxygen is not explosive or combustible in any way.... it is simply an oxidizer.

Either use a fan, run around with your spudgun above your head like a retard, or use a compressor and quick connect.
  • 0

User avatar
benstern
Donating Member
Donating Member
 
Posts: 909
Joined: Wed Sep 21, 2005 8:24 pm
Reputation: 0

Unread postAuthor: jjjd » Fri Mar 16, 2007 7:08 pm

This would just have a solenoid, this way it would be faster/ easier , no opening the ball valve
  • 0

User avatar
jjjd
Staff Sergeant
Staff Sergeant
 
Posts: 117
Joined: Wed Nov 29, 2006 12:39 pm
Reputation: 0

Unread postAuthor: chaos » Fri Mar 16, 2007 7:36 pm

risto:: DO NOT USE PURE OXYGEN! THAT IS DISASTROUS! My plan was to use a compressed air tank. NEVER- UNDER ANY CIRCUMSTANCE -HAVE PURE OXYGEN IN A COMBUSTION CHAMBER!!!! (if you value your life at least)


i find that hard to comply with, i have known somebody with nearly exact same cannon as mine and they used pure oxygen, it was a lot more powerful, but it did no harm.

peace
chaos
  • 0

User avatar
chaos
Brigadier General
Brigadier General
 
Posts: 1205
Joined: Wed Jan 17, 2007 8:31 am
Reputation: 0

Unread postAuthor: benstern » Fri Mar 16, 2007 8:20 pm

Have you people even read my post, or am I going to have to beat the ignorance out of you myself!?!?!?

This would just have a solenoid, this way it would be faster/ easier , no opening the ball valve

Solenoid valves need pressure to work!! Atmospheric pressure plus the infinitesimally small vacuum created by a fan won't work.
  • 0

User avatar
benstern
Donating Member
Donating Member
 
Posts: 909
Joined: Wed Sep 21, 2005 8:24 pm
Reputation: 0

Unread postAuthor: medievalman » Fri Mar 16, 2007 8:57 pm

benstern wrote:pure oxygen is not explosive or combustible in any way.... it is simply an oxidizer.


You are right, pure oxygen is not combustible, but as soon as it is added to something that is(in this case, propane) it becomes extremely volatile, increasing the power of the combustion(or at least the speed) significantly.
  • 0

Join the AirAssault Army!

Welcome to Minnesota, Land of 10,000 Lakes, and 10,000,000,000 Mosquitoes.
User avatar
medievalman
Captain
Captain
 
Posts: 319
Joined: Tue Dec 05, 2006 5:52 pm
Location: Central Minnesota
Reputation: 0

Unread postAuthor: benstern » Fri Mar 16, 2007 10:57 pm

WRONG WRONG WRONG WRONG!!!!!!

Oxygen cannot become "extremely volatile." An oxidizer does not become volatile. The saltpeter in gunpowder does not become volatile... the charcoal does.

Propane needs a certain percentage of oxygen to burn correctly.

In typical atmospheric air the best propane ratio to air is 4.18952% (I memorized that)

Using the chart below... which I made a few (eight to be exact) months ago and dug up just to teach you sorry butt.... we can see how this works.

<img src="http://img459.imageshack.us/img459/2274/concentrationpx5.gif">

If you increase the oxygen content in the gases but into the chamber you must also increase the amount of propane put in the chamber. However now it is considered a hybrid, now isn't it?
  • 0

User avatar
benstern
Donating Member
Donating Member
 
Posts: 909
Joined: Wed Sep 21, 2005 8:24 pm
Reputation: 0

Next

Return to Combustion Cannon Discussion

Who is online

Registered users: Bing [Bot], Exabot [Bot], Google [Bot], Yahoo [Bot]

Reputation System ©'