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 65 users online :: 2 registered, 0 hidden and 63 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Flow Regulators for Metering Propane

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

Flow Regulators for Metering Propane

Unread postAuthor: mark.f » Thu Jul 19, 2007 10:07 am

I simply ask this because I've seen flow regulators everywhere, and their cheap. There are both the fixed kind, and the adjustable kind like you find at Home Depot next to the regular pressure regulators.

Anyways, I was thinking something like this.

You have a fixed flow regulator. It delivers a flow-rate of 0.1 gallons per minute.

So, that's 378.5 mL per minute, or 6.3 mL per second.

So, if you have a 2L combustion chamber, then for a 4.2% propane to air mixture, you would simply open the valve before the flow regulator for 13-1/3 seconds.

Makes sense?
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: JDP12 » Thu Jul 19, 2007 10:20 am

yea it makes sense......but the tricky part is timing it right.... i mean how do you time 13-1/3 sec?
  • 0

"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: mark.f » Thu Jul 19, 2007 11:21 am

Counting. I can count pretty accurately in my head. I used to use a little propane stove regulator and count a little over seven seconds when fueling one of my old launchers.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: homedepotpro » Thu Jul 19, 2007 12:27 pm

yes but the flow is also going to change with the pressure in the tank right, so when your fuel is running low on pressure you won't get as much fuel it your 13 sec fill
  • 0

User avatar
homedepotpro
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 443
Joined: Sun Nov 26, 2006 1:00 am
Reputation: 0

Unread postAuthor: mark.f » Thu Jul 19, 2007 2:57 pm

Good point. Then you'd need some sort of primary regulator to bring it down to a lower fueling pressure...

So nevermind.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: noname » Thu Jul 19, 2007 5:34 pm

I found that funny. Also, the only flow regulators I can find are $20, the same as pressure regulators. Instead of getting a flow regulator, you can always use 1 ball valve as a "meter" and time the seconds.
  • 0

User avatar
noname
Lieutenant General
Lieutenant General
 
Posts: 2699
Joined: Mon Apr 10, 2006 9:19 pm
Location: Bay Area, CA
Country: United States (us)
Reputation: 9

Unread postAuthor: paaiyan » Thu Jul 19, 2007 5:36 pm

I don't know about y'all but the propane tanks i get for my gas grill have a 10 PSI flow regulator on them... Just an idea.
  • 0

"Who ever said the pen was mightier than the sword, obviously, never encountered automatic weapons."
-General Douglass MacArthur

Read my dog's blog - Life of Kilo
User avatar
paaiyan
Major General
Major General
 
Posts: 2140
Joined: Wed Dec 27, 2006 10:03 pm
Location: Central Oklahoma
Country: United States (us)
Reputation: 1

Sponsored

Sponsor
 


Unread postAuthor: jimmy101 » Fri Jul 20, 2007 6:24 pm

The simplest "flow regulator" is just the standard benzomatic torch head. Unscrew the burner/mixer assembly (not the pipe to valve junction). You'll see a tiny hole. Not exactly sure how small the hole is but a piece of 30G wire won't fit into it so it is less than 0.01 inch in diameter.
Image
(Ignore the syringe etc., just look at the "unscrew".)

Rough measurment of the flow into a syringe puts the flow rate at 5~10cc/second. WAG estimate for a 100in<sup>3</sup> chamber would be 5~10 seconds.

As folks have pointed out, the flow will change with the ambient temperature. So, if 4 seconds works at 90F it will take longer at 50F.

A flow regulator should never be used with high pressure gases (like CO2) or in a situation where the chamber being filled is actually being pressurized in the process. A flow regulator between two closed chambers will eventually equilibrate the pressure in the two chambers.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3128
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Return to Combustion Cannon Discussion

Who is online

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

Reputation System ©'