FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 


Reverse flow build questions-- KAM or Alien??
Goto page 1, 2, 3  Next
 
Post new topic   Reply to topic    The Smoke Ring Forum Index -> Cookers
View previous topic :: View next topic  
Author Message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Sun Oct 03 10 6:34 am    Post subject: Reverse flow build questions-- KAM or Alien?? Reply with quote

I am in the process of a 115 Gallon propane tank build. I followed the Calculator in the sticky.

The propane tank is 24" X 60". I came up with a commercial water heater tank (reasonably thick compared to a residential). It is 18" round and I cut it down to 32" long, inside. It is uses a Vogelzang door (salvaged from my double barrel build), on the end of it. The Top of the fire box is about 2" below the center line of the propane tank.

I have used two 20-odd inch (can't remember what they are exactly at the moment) inch pieces of 4" ID steam pipe for stacks (per the calculator). One is set at the lower grate level, the other is at the upper grate level. both with dampers. The firebox to cook tank hole is about 7 by 11. I made the opening bigger than the calculator said and added a damper so it could be tweeked.

Intake is just an oval hand hole (it was a clean out hole for the water heater), slightly under the slide out basket, aimed up at a 45* angle. I have a 25 cfm aluminum bodied scroll fan for induction with a Watlow.

WHEeWW .. that's a mouth full. Now my question. Very Happy

How much RF Plate gap do i need at the opposite end of the firebox? I saw something about the area of the gap should be the area of your stack diameter. I'm not certain that makes sense (maybe it does) because it doesn't take in account of stack volume.

Any help appreciated. I called on KAM and Alien as they seem to have a great handle on this.
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
k.a.m.
BBQ Mega Star


Joined: 12 Dec 2007
Posts: 26012
Location: Southeast Texas.

PostPosted: Sun Oct 03 10 8:02 am    Post subject: Reply with quote

Rob, I always have the opening at the R/F plate end the same Sq.in. as the opening from the firebox to the cooking chamber. In your case you have a slightly larger hole than needed at 77 Sq.in. Your tank is 24'' in diam. and your dome end reduces in depth to the edges I am not sure how much. So figure the Sq.in. needed and that would be my gap. I am thinking about 2.5'' back from the weld line will bring you into specs. But I am guessing because I do not know the depth of the end of the tank dome. I hope this helps. Smile
_________________
Always remember slow and steady wins the race.

Hybrid Cooker
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Sun Oct 03 10 11:55 am    Post subject: Reply with quote

It does... I'll go out and take some measurements of the dome tomarrow and report back.

Thanks!
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
Alien BBQ
BBQ All Star


Joined: 12 Jul 2005
Posts: 5426
Location: Roswell, New Mexico

PostPosted: Sun Oct 03 10 12:41 pm    Post subject: Reply with quote

KAM is on the money with this one, the gap at the turnaround end should never be smaller than your cooker section inlet. The stack deals with negative pressures and velocity while the turnaround is more concerned with flow. The easier you can make the turnaround, the better. in fact, if you could put a 2 inch lip, bent at a 45 degree angle at the turnaround on the plate you could increase your flow by lessening the turbulence at that point.
_________________
https://www.linkedin.com/in/michaeloberry
Back to top
View user's profile Send private message Send e-mail Visit poster's website Yahoo Messenger
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Sun Oct 03 10 9:55 pm    Post subject: Reply with quote

as soon as the ol lady gets around I'll get to work! I May have to make another trip out for some 2" strap, depending on what is left of the plate, once I fit it to the tank.

I'll take some pics a little later so you guys can see what I have goin' on. I know the round tank is not optimal with the way I set it up with the lip at the top(just above the square damper), but it's a budget build based on what I can reasonably get my hands on. I would have rather build a square box from plate and made the top of the fire box part of the RF Plate, like you all do.

Any Preference to how high off the bottom of propane tank The plate should be? Or is it critical? The way I am looking now It can be as little as 7 or 8 inches off the bottom and as high as the bottom of the bottom of the door at 12". In other words, i could fit the rf plate around the fire box at the level of the very top of the firebox opening, or put it completly above the fire box.

I'm sure this is confusing without the pics!

Thanks again guys.

I have HOURS into reading this forum and see KAM and Alien, Providing good information to anyone who needs it. You are great model for the community.
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Sun Oct 03 10 11:08 pm    Post subject: Reply with quote

Well... Never mid for now.... Just went out the suburban and the flex plate is trashed. Evil or Very Mad no smoker stuff today. 4wd + tri y headers + 3/4 ton = lots of fun for me all day long. Evil or Very Mad

Sorry.... I'll update in a couple days.
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
k.a.m.
BBQ Mega Star


Joined: 12 Dec 2007
Posts: 26012
Location: Southeast Texas.

PostPosted: Mon Oct 04 10 8:03 am    Post subject: Reply with quote

Rob, sorry to here about the Suburban. On your plate height you can run the same plane as your opening and be just fine. A Lang is right at the grates on the firebox side with about a 3'' fall to the opposite end. The one I built is 4'' from the grate on the firebox end and 5'' on the opposite.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Mon Oct 04 10 11:45 am    Post subject: Reply with quote

I am too...LOL! Well I went about as far as I could on the 'burban and parts will be here friday. The tri y headers are the worst. Gale Banks make some nice stuff, but it's still a pain to get out of the way.

Decided to get back to the smoker in the mean time. I was wondering how much fall... that was one of my questions. I'll do that.

I take it you mean 2.5" from the weld, toward the dome? I went out and took some measurements, and found the peak of the dome is about 6" from the weld. the dome starts turning in about 3" - 3 1/2" away from the weld. In other words the dome is about 2 1/2" deep.

I was going to post pictures but it looks like need a photo bucket account. I'll get on that. A picture tells a thousand words.

And thanks again for your help KAM.
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Mon Oct 04 10 12:11 pm    Post subject: Reply with quote

Let me try a couple

Here is the where the fire box meats the cook chamber with a not so fancy damper ( I am trying to keep this simple as possible for money and time).


_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Mon Oct 04 10 12:22 pm    Post subject: Reply with quote

Damper closed...



A shortened Industrial water heater tank used as a fire box meets the proane tank.



A so/so job on the stacks due to my sloppy hole cutting.



Th smoker so far...



Here is a view of the end cap measurement. the angle of the camera makes it look like the tape is past the end of the peak of the dome but it isn't.



Vogelzang door from previous build



The start of the pull out basket

_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Mon Oct 04 10 12:41 pm    Post subject: Reply with quote

Stack at upper and lower grate level (there will be a middle also -- all removable). Alien said something somewhere about balancing upper and lower grates with duals and dampers. I thought I would give it a shot.



The doors worked out well. I noticed how KAM cut out most of the door, welded hinges, then cut the rest out. I tried it and it works very well. If your wondering how I am going to seal that with those hinges, I plan on using 1" strap steel to the inside of the doorways. I know this will cost me some grate width, having to move the tracks inward but I'd rather deal with that than welding the strap to the outside of the doors and possibly warping them. That An I am used to welding while standing on my head! LOL!

I Noticed a buddy's smoker that camelbacked from the single long door. So I decided on two doors so I would have a band of tank left in the middle of the doors.



The common shaft Exhaust damper handles I have yet to weld on with the cover style dampers.


_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
k.a.m.
BBQ Mega Star


Joined: 12 Dec 2007
Posts: 26012
Location: Southeast Texas.

PostPosted: Mon Oct 04 10 7:22 pm    Post subject: Reply with quote

Rob, the way your doors are cut you can end your plate at the dome weld. I believe that will give you plenty of turn around for your heat/smoke. You can make a template and draw a Sq.in grid on the pattern to check if you like.
Your damper looks great, as does the rest of your build. Very Happy Your doing some nice work, I will be watching for more pics and updates. Very Happy
_________________
Always remember slow and steady wins the race.

Hybrid Cooker
Back to top
View user's profile Send private message
Hell Fire Grill
BBQ Super Pro


Joined: 17 Mar 2007
Posts: 3921
Location: Pickler's Puragatory!!

PostPosted: Mon Oct 04 10 11:00 pm    Post subject: Reply with quote

Looks like you'll be cookin in no time. Keep up the good work, take lots of pics and drink pleny of beer.
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Tue Oct 05 10 6:07 am    Post subject: Reply with quote

thanks guys.

I think i will go right along with the beer idea.... it is 5....
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
slowpokey
Newbie


Joined: 12 Sep 2010
Posts: 40
Location: Newark, Tx.

PostPosted: Tue Oct 05 10 8:43 am    Post subject: Reply with quote

looks awsome i will be following you as well, being i am about to get started on one myself. i may have more questions to ask on my firebox.
i have also been pondering on the double stack.
what about a single stack in between the top and bottom rack on the end of the smoke chamber above the firebox.
i noticed the langs have one stack toward the top
_________________
loving life
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Tue Oct 05 10 10:05 am    Post subject: Reply with quote

I don't know... we'll see how it works (the stacks). so far it drafts great without the RF plate just burning it out good and proper. got it really hot tonight nothing really moved around. I just aimed the 25 cfm fan in the intake hole... nothing sealed and let it loose with the controller. Really heats up fast like that. I burned an entire skid in nothing flat. Now I'll hose it out and start work until the flex plate gets here. I am surprised none of the paint burned off. It was push'n 600 out the top chimney...Rolling Eyes


_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
Alien BBQ
BBQ All Star


Joined: 12 Jul 2005
Posts: 5426
Location: Roswell, New Mexico

PostPosted: Tue Oct 05 10 11:36 am    Post subject: Reply with quote

This was not a glass lined tank was it?
_________________
https://www.linkedin.com/in/michaeloberry
Back to top
View user's profile Send private message Send e-mail Visit poster's website Yahoo Messenger
kickassbbq
BBQ Pro


Joined: 06 Jan 2006
Posts: 664
Location: mn

PostPosted: Thu Oct 07 10 1:44 am    Post subject: Good Question!!!! Reply with quote

Now THAT is a GREAT question!!!!

Hey Alien BBQ Man!!! Hope all is well with you and yours.
Ed
_________________
Smoke On!!!!!!
www.kickassbbq.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Thu Oct 07 10 11:45 am    Post subject: Reply with quote

Alien BBQ wrote:
This was not a glass lined tank was it?


Nope... that would be along the lines of a residential unit. I think those even have some kind of spiral line in them now too. This one was and industrial unit and is fairly old. Probably early to mid eighties. It held (3) 2400w elements and ran on 240. It's probably pretty rare to come across a tank like this. this one was used to heat water for several film and plate processors in a huge dark room(old technology). The only problem with this one was a leak and the clean out door. I saw it and my Lead said i could have it. Too bad the insulation wasn't worthy of the fire box temps.... i would have kept it.
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
evil16v
BBQ Fan


Joined: 25 Sep 2009
Posts: 154
Location: Kansas

PostPosted: Thu Oct 07 10 11:50 am    Post subject: Reply with quote

I'll get back on this shortly. the flexplate for the 'burban got here early. I got it bolted up... now everything has to go back together. I suspect it will be done tomorrow night and i will back on the smoker Friday night. I have the reverse flow plate steel, the flattened expanded, box, angle, and strap steel now.
_________________
Rob
115 Gal. Reverse Flow Build, water heater fire box, forced induction/ PID controller
Kory's 305 Gal. build
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    The Smoke Ring Forum Index -> Cookers All times are GMT + 8 Hours
Goto page 1, 2, 3  Next
Page 1 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2002 phpBB Group