# New Electric Build



## Jonok (Sep 14, 2020)

I scored an open-bottom insulated propane-fired Peking duck oven (roughly sheet pan internal size by 60” vertical internal dimensions above the burners.

Removed the propane and sealed the bottom, installed 2 3600W elements (top and bottom, switchable to allow broiling, and both on a PID.  (240, of course) 
Initial runs show easy control from ambient to 500 degrees. 

Have constructed an initial separate smoke generator based on my MES generator design. This one is PID controlled and vents directly to the smoker. Smok production is independent of smoker temp.

Will provide pictures presently, but I think it’s the cats pajamas!


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## Sowsage (Sep 14, 2020)

Nice . would love to see it in action! With that kind of temp control and seperate smoke generator the stuff you can do is limitless.


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## Jonok (Sep 14, 2020)

I’m fairly stoked, because I can make all the thin blue smoke I want and trickle it through the cook chamber as I need it.  Nothing bitter, and presumably I can make all the nitric oxide I want so I’ll get a pretty smoke ring too.....


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## Jonok (Sep 14, 2020)




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## Sowsage (Sep 14, 2020)

Jonok said:


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Looks good! Cant wait to see what you cook in it!


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## Jonok (Sep 14, 2020)

Still working on the top vent hole.  Needs to get through 2 layers of galvanized 16 ga and one layer of stainless that’s thicker.  Burned up the bimetal 2.5” hole saw on the first layer of soft stuff, so I’m looking at carbide or plasma to finish the job...


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## Sowsage (Sep 14, 2020)

Jonok said:


> Still working on the top vent hole.  Needs to get through 2 layers of galvanized 16 ga and one layer of stainless that’s thicker.  Burned up the bimetal 2.5” hole saw on the first layer of soft stuff, so I’m looking at carbide or plasma to finish the job...


That stainless will tear up some stuff. Get the carbide and use a little oil. Take it slow. Heat is your worst enemy....im sure you know this already....keep us posted!


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## Jonok (Oct 11, 2020)

So it’s working with  a PID controlled top and bottom element (3500W each, 250v with a contactor to turn them on and off, elements are also individually switched, so if I don’t want broiling action from the top I can shut it down.  Hits 250 from ambient with both elements in about 5 min.  External PID controlled smoke generator with 120v element in sealed container with aquarium pump for positive pressure.  Catches fire and goes out on command.  Refractory cement in bottom of generator to prevent burnouts.

more pictures soon.


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## Jonok (Dec 12, 2020)

It works


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## Jonok (Dec 12, 2020)

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Mods please delete, duplicate post


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## bill1 (Jan 7, 2021)

Very nice!  If you've got the power, it's hard to beat electric heat, as long as you can separately generate enough (good) smoke .  

But I'm not fully understanding your smoke generator.  You have a small 120VAC element surrounded by pellets?  It's controlled by a PID that's informed/controlled by what?  A temperature probe?  Where is that probe located with respect to the element and wood?  Pictures of this smoke generator would be appreciated!  

Sounds great that you remove pellet heat upon flames (as determined by high temp on a probe someplace?) but I assume your wood still burns up to char at that point...so do you have a gravity-feed or other auto-feed mechanism for replenishing your smoke "fuel"?   Is there any control on the air supply to the pellets/chips?  How does that whole smoker mechanism "breathe"?


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## Jonok (Jan 8, 2021)

Basically, there is a wood hopper in a sealed container that has a 500w element under it.  The PID control cuts out at a temp that indicates that the wood has caught fire.  When  that occurs the element shuts off and the air intake solenoid to the generator closes and the fire goes out.  This repeats so that we don’t just destructively distill the wood, so we actually get blue smoke and a smoke ring.  The wood hopper holds about a gallon of chunks and seems to make good smoke for about 12 hrs.


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## Jonok (Jan 8, 2021)

So this is the current test bed iteration of the generator.  It seems to do everything we need.  When we’re convinced we’ve got all the bugs worked out, we’ll fabricate a stainless version that is attached to the smoker.

I’d show the inside of the generator, but I’ve got butts in the smoker now and it’s running great, so I don’t want to open it and screw anything up.


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## Coreymacc (Jan 8, 2021)

Jonok said:


> View attachment 479205
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> So this is the current test bed iteration of the generator.  It seems to do everything we need.  When we’re convinced we’ve got all the bugs worked out, we’ll fabricate a stainless version that is attached to the smoker.
> ...


Waiting for the pics of the inside. I'm designing a large smoker now and if your willing I may "borrow"  some ideas from you on your generator.  The smoker design is locked in but my generator ideas are a little thin right now. 

Corey


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## bill1 (Jan 8, 2021)

Thanks Jonok!  It sounds like the controller turns off BOTH inlet airflow _and _electric  power to the wood chip heater when the temp exceeds a Hi set point corresponding to burning.  
And then the controller turns them both on again as the temperature decreases below a Lo set point.  
Could I ask what you're using for Hi and Lo temp set points?


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## Jonok (Jan 8, 2021)

Currently 220 C hi and 170 low., but it’s sort of irrelevant as the element alone won’t increase the temp in the generator much above 100c even without convective losses, so when it gets higher than that it’s because somethings burning and creating additional heat.


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## forktender (Jan 9, 2021)

Are you going to wire wheel it to get the swirl finish on it? I think that would look sharp.


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## Jonok (Jan 9, 2021)

This is what was left after a 10 hr cook with the generator filled at the beginning with cherry chunks (dry orchard prunings from last year)


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## Jonok (Jan 9, 2021)

You are looking down into the  wood hopper which is still in the generator sitting on top of the element.


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## Jonok (Jan 9, 2021)

This is the inside with the bucket removed and the whole thing open.


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## Jonok (Jan 9, 2021)

Really just leaves a little ash.  Was still making smoke when i shut it down yesterday.


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## Jonok (Jan 9, 2021)

The probe for the PID is obviously mounted in the lid of the housing as you can see in the previous picture with it closed.


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## bill1 (Jan 9, 2021)

Jonok said:


> This is what was left after a 10 hr cook...


Ah, so there's an inner bucket that holds the smoking wood.  Holes in the bottom of this inner hopper/pail?  Or air enters that inner region from the top only?  
Is the temp probe located in the top, close to the smoke exhaust?  
Thanks for sharing!  Hard to beat pictures!


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## Jonok (Jan 9, 2021)

If you look at the empty generator pic, the pipe terminates above the element.  The way I load it is to put the empty bucket in the generator and onto the pipe (hole in side of bucket accommodates intake 1/2” pipe) and then load bucket with closely stacked chunks. That way, air intake is at bottom of wood.


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## bill1 (Jan 9, 2021)

Jonok said:


> ...put the empty bucket in the generator and onto the pipe (*hole in side of bucket* accommodates intake 1/2” pipe) and then load ...


Genius idea.   This also minimizes air flow in the space between inner and outer buckets so outer wall stays cooler, reducing wasted heat and power draw.


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## Jonok (Jan 9, 2021)

Temp probe (generic K type) is located on top diametrically opposed to outflow.  That way, presumably, it is measuring ambient as opposed to flue gas temp.  Regardless, when it hits 100c or better than the max achievable ambient temp without combustion,  something is on fire.  I’m pretty sure once I optimize the burn time vs off time to continue to produce excellent smoke, I can substantially reduce the amount of time with “complete” combustion, but keep the temps high enough that NOX etc production remains very high. 
My phone died yesterday afternoon and I was unable to take food porn pix, but I had about a 3/4” medium pink ring on all three butts, and the total wood input was probably 2 pounds of chunks.  Bark was really tasty, but it was actually thick enough that I will consider turning off the top element for the latter portion of the smoke in the future.


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## Jonok (Jan 9, 2021)

Pretty sure the world will get better when I weld up an insulated stainless combustion box rather than doing all of this in a $10 garbage can with a few bucks worth of refractory cement in the bottom


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## Jonok (Jan 9, 2021)

If anyone has a source for a couple of 1-1.5’ 250w linear heating elements which I could incorporate into a future firebox, I’d be appreciative.  The way power is distributed in the beast at this point, 120v would be optimal, but it’s not the end of the world if I need to re-engineer a bit.


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## bill1 (Jan 9, 2021)

Jonok said:


> If anyone has a source for a couple of 1-1.5’ 250w linear heating elements which I could incorporate into a future firebox, I’d be appreciative.  The way power is distributed in the beast at this point, 120v would be optimal, but it’s not the end of the world if I need to re-engineer a bit.


The $10 charcoal starter products in your pics seem hard to beat.  But another option might be 240V water heater elements used at 120V.  At their intended voltage/power, only water will wick away the sort of watts-per-sq.inch  involved without the units quickly failing.  But at half voltage, the power goes down by 4X.  They still have a tendency to get a bit too red in ambient air so that their lifetime is limited to months, not years.  But add a high-current diode in the 120Vac line and you knock power down another 2X.  Then they're pretty usable.  Just a suggestion.  Like I said the charcoal starter ring looks great and are available everywhere.   

Another cheap trick you might find useful is that light dimmer switches work well to adjust power density for elements <600W, their typical rating.


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