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


Automatic draft control "flapper"

 
Post new topic   Reply to topic    The Smoke Ring Forum Index -> Tech-Talk
View previous topic :: View next topic  
Author Message
smootz
BBQ Super Fan


Joined: 12 Nov 2011
Posts: 444
Location: Kitts Hill, Ohio

PostPosted: Wed Nov 30 16 9:33 am    Post subject: Automatic draft control "flapper" Reply with quote

A few years ago I saw a very simple but very effective automatic draft control on a large propane tank based stick burner. Unfortunately it was at a bbq restaurant and I could not see or obtain much information.

The whole setup was homemade. It consisted of some sort of oven thermometer wired to a solenoid actuator. The actuator pulled a wire that opened and closed a "flap" style vent on the fire box.

It was super simple but worked very well. I watched it open and close several times. BTW - the BBQ was great!

It would be easily fabricated if i could find a thermostat that would work within smoker temp ranges to send a signal to the solenoid.

Is there a reason why blowers are typically used instead of automatic dampers?
_________________
150 gallon vertical
propane pig
180 RF
Back to top
View user's profile Send private message
biker.chef
BBQ Pro


Joined: 28 Jun 2010
Posts: 558
Location: Burnsville Minnesota

PostPosted: Wed Nov 30 16 9:47 am    Post subject: Re: Automatic draft control "flapper" Reply with quote

smootz wrote:

Is there a reason why blowers are typically used instead of automatic dampers?


Blowers are simple to use and they are easy to couple to PID controller.
A PID is either fan on or fan off. No fan speed adjustments or
partially opening a damper.
I guess that an advantage of the mechanical system.
_________________
-------
Every Day, Thousands Of Innocent Plants Are Killed By Vegetarians.
Help End The Violence.
EAT BACON
Back to top
View user's profile Send private message
k.a.m.
BBQ Mega Star


Joined: 12 Dec 2007
Posts: 25980
Location: Southeast Texas.

PostPosted: Wed Nov 30 16 7:36 pm    Post subject: Reply with quote

On typical draft controllers blowers are used on the intake to force air into the firebox or stop the flow completely. The flapper you're describing sounds like what J&R Oylers use to control the temps in their rotisseries.
_________________
Always remember slow and steady wins the race.

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


Joined: 12 Nov 2011
Posts: 444
Location: Kitts Hill, Ohio

PostPosted: Thu Dec 01 16 3:39 am    Post subject: Reply with quote

I briefly looked into this a few years back. The system is super simple and could be easily fabricated if I could find the right kind of thermostat control. It may be as simple as the thermostat from an old kitchen oven. All I need is something that will trip a solenoid actuator. Just "on-off". Trap door is either open or closed, nothing variable or progressive.
_________________
150 gallon vertical
propane pig
180 RF
Back to top
View user's profile Send private message
animal
BBQ Pro


Joined: 05 Nov 2007
Posts: 934
Location: Wisconsin

PostPosted: Thu Dec 01 16 5:03 am    Post subject: Reply with quote

Something like this

http://www.maverickhousewares.com/ttt-01-tip-top-temp/
_________________
New Braunfels Offset
Smoke Hollow #5
Lang 48 D
Acorn Komado
And a couple of Weber kettles
Back to top
View user's profile Send private message
smootz
BBQ Super Fan


Joined: 12 Nov 2011
Posts: 444
Location: Kitts Hill, Ohio

PostPosted: Thu Dec 01 16 7:20 am    Post subject: Reply with quote

animal wrote:
Something like this

http://www.maverickhousewares.com/ttt-01-tip-top-temp/


That is a cute little unit but not exactly what I am looking for. I need something that will react to the temperature in the cooking chamber and give me an electric impulse (preferably 12 volt) that would open or close a simple solenoid actuator. The actuator is connected by a wire or lever to open and close the flapper door on the firebox.
_________________
150 gallon vertical
propane pig
180 RF
Back to top
View user's profile Send private message
biker.chef
BBQ Pro


Joined: 28 Jun 2010
Posts: 558
Location: Burnsville Minnesota

PostPosted: Thu Dec 01 16 7:26 am    Post subject: Reply with quote

A BBQ Guru or a PID off Ebay would do the job nicely.
More bucks it would give you a set it and forget it controler.
_________________
-------
Every Day, Thousands Of Innocent Plants Are Killed By Vegetarians.
Help End The Violence.
EAT BACON
Back to top
View user's profile Send private message
smootz
BBQ Super Fan


Joined: 12 Nov 2011
Posts: 444
Location: Kitts Hill, Ohio

PostPosted: Thu Dec 01 16 8:49 am    Post subject: Reply with quote

If everyone is using blowers instead of flappers there must be a reason. I need to lurk for a while and get educated on PID. (Not sure what that stands for).
_________________
150 gallon vertical
propane pig
180 RF
Back to top
View user's profile Send private message
jess
BBQ Super Pro


Joined: 26 Sep 2007
Posts: 1743
Location: Fl.

PostPosted: Thu Dec 01 16 6:38 pm    Post subject: Reply with quote

proportional-integral - derivative controller..
And with that said I bet most people still do not
know what that means... Smile
Back to top
View user's profile Send private message
smootz
BBQ Super Fan


Joined: 12 Nov 2011
Posts: 444
Location: Kitts Hill, Ohio

PostPosted: Fri Dec 02 16 1:56 am    Post subject: Reply with quote

jess wrote:
proportional-integral - derivative controller..
And with that said I bet most people still do not
know what that means... Smile


It sounds like it is more than "on-off". I am guessing the blowers like Stoker and Guru are variable speed depending on need? Sorry for the total ignorance. No one I know has anything like that for me to see.
_________________
150 gallon vertical
propane pig
180 RF
Back to top
View user's profile Send private message
k.a.m.
BBQ Mega Star


Joined: 12 Dec 2007
Posts: 25980
Location: Southeast Texas.

PostPosted: Fri Dec 02 16 3:52 am    Post subject: Reply with quote

This one has been getting some good reviews on the competition trail. I watched this business grow from a go fund me account.
http://theperfectdraft.com/
_________________
Always remember slow and steady wins the race.

Hybrid Cooker
Back to top
View user's profile Send private message
biker.chef
BBQ Pro


Joined: 28 Jun 2010
Posts: 558
Location: Burnsville Minnesota

PostPosted: Fri Dec 02 16 4:03 am    Post subject: Reply with quote

I've not used a guru but I don't think it is variable speed.
My controller will pulse the fan. Short bursts of on/off.

I did a posting a few years ago about a DYI PID. I can try to
find it. But if your not familiar with wiring your best sticking
with with a commercial solution.
The advantage of an electronic controller is that that homes in on the
desired temperature. As the smoker gets to set temperature the controller
will start pulsing the fan so it doesn't over shoot the temp.
As it senses the smoker is cooling off it will start the fan again.
It "learns" over time and keeps the smoker at constant temperature.

A mechanical thermostat will keep the air flow open until the
smoker is at temperature. The fire is still hot so the temp will rise well
past the desired temperature. It will close down until the smoker has
cooled past the turn on temperature.
So the problem is you will get spikes and dips in temperatures
_________________
-------
Every Day, Thousands Of Innocent Plants Are Killed By Vegetarians.
Help End The Violence.
EAT BACON
Back to top
View user's profile Send private message
PaleAle
BBQ Fan


Joined: 17 Apr 2011
Posts: 206
Location: Colonial Heights, VA

PostPosted: Fri Dec 02 16 6:45 am    Post subject: Reply with quote

Depends on your DIY skills you can look into heater meter. I love mine!!!!
Back to top
View user's profile Send private message
RodinBangkok
BBQ Super Fan


Joined: 30 Dec 2006
Posts: 486
Location: Bangkok Thailand

PostPosted: Fri Dec 02 16 7:29 pm    Post subject: Reply with quote

Take a look at using an Arduino controller with a servo to control a butterfly valve on your exhaust, it can also easily control the intake fan via PID software. Probably won't cost you more than $50 bucks if you have some tinkering skills.
_________________
Rod
Back to top
View user's profile Send private message
mbellot
BBQ Super Fan


Joined: 16 Aug 2010
Posts: 421
Location: Illinois

PostPosted: Fri Dec 02 16 11:07 pm    Post subject: Reply with quote

I've used one from Auber with good success on a couple different smokers/grills. I even played with it and some homebrew electronics (SSR) to make a crockpot sous vide setup.

The one thing I found with the Auber (maybe all PID controllers, not sure) is that you are better off getting close to your target temperature (50F or so) before engaging the control, otherwise the blower will tend to ramp the fire up too high and you end up with an overshoot that risks snuffing your fire when it's trying to bring the temperature back down.
Back to top
View user's profile Send private message
biker.chef
BBQ Pro


Joined: 28 Jun 2010
Posts: 558
Location: Burnsville Minnesota

PostPosted: Fri Dec 02 16 11:35 pm    Post subject: Reply with quote

mbellot wrote:

The one thing I found with the Auber (maybe all PID controllers, not sure) is that you are better off getting close to your target temperature (50F or so) before engaging the control, otherwise the blower will tend to ramp the fire up too high and you end up with an overshoot that risks snuffing your fire when it's trying to bring the temperature back down.

I don't have that problem. I think it maybe it's a function of the smoker.
Mine is a small vertical smoker so the fire is small too.
_________________
-------
Every Day, Thousands Of Innocent Plants Are Killed By Vegetarians.
Help End The Violence.
EAT BACON
Back to top
View user's profile Send private message
smootz
BBQ Super Fan


Joined: 12 Nov 2011
Posts: 444
Location: Kitts Hill, Ohio

PostPosted: Sat Dec 03 16 11:31 pm    Post subject: Reply with quote

biker.chef wrote:

A mechanical thermostat will keep the air flow open until the
smoker is at temperature. The fire is still hot so the temp will rise well
past the desired temperature. It will close down until the smoker has
cooled past the turn on temperature.
So the problem is you will get spikes and dips in temperatures



Best explaination I have heard. Thanks. This is a winter project so I will start researching DIY blower setups. The one KAM mentioned looks pretty good too.
_________________
150 gallon vertical
propane pig
180 RF
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 -> Tech-Talk All times are GMT + 8 Hours
Page 1 of 1

 
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