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Heat Gun...Max Capability?
JETROASTER
A few short videos;
1) Turned on the heat, I was a bit surprised by the increase in back-pressure. I expected some, but it caught me off guard a bit. I may drill a few more holes.
[video]http://www.youtube.com/watch?v=CLdzDMXhY7E[/video]

2) 1lb beanflow test...cold.
[video]http://www.youtube.com/watch?v=S4mcPKL0glk[/video]

3) 2lb beanflow test...cold.
[video]http://www.youtube.com/watch?v=ZsWSgt2M0IY[/video]
I don't intend to roast 2 lbs., but I was curious if it would sustain a plume. It did.

I don't have any plans to automate this thing, but how would the thermal expansion effect control systems when it comes time to control heat and airflow together? -Scott
 
seedlings
Did the heat increase pressure by 15%? Wow.

How much chamber is above the bean bed? It looks like the top of your chamber gets smaller, which increases pressure - possibly enough pressure, combined with the height of expanded beans, to start launching them out. Have you tried bean flow with 1.75# of roasted coffee?

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
JETROASTER
Chad,
With a 1# load, I've 9" of space above the beans. The 3rd video is a 2# load(green)...(that was just to check the blower ability). That leaves no room. I might be able to pull off a 1.5#, but I think expansion will likely kill that option too.
1lb of beans creates 2" pressure, adding another 1" for every .5 lb after that. I tested all the way up to the 2lb load. All the other pressure you see is created below the distributor/perf plate.
I haven't hooked up an exhaust system yet, so that pressure has to be contended with as well.

Hopefully in the next 2 days, I'll actually roast some coffee!! -Scott
 
allenb
Your rig is looking like it's getting ready to start making some smoke!


The plume is nice and I don't see much in the way of bounce. I can't wait to see this guy or gal in action cooking coffee.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
JETROASTER
Prepped for transport to the launch-pad. T minus 48hrs. -Scott
JETROASTER attached the following image:
max_pak.jpg

Edited by JETROASTER on 03/04/2011 10:40 AM
 
Ringo
I just see in a thousand year, somebody will dig this up. It will still be shiny and they will wonder what it was? Maybe they will turn it into a lamp for there spaceship. Really nice work!!!
Ringo
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
jkoll42
Don't get too close to a border crossing or airport... TSA might get really "friendly" with you if they saw that!!!
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
seedlings
Maybe you posted this somewhere, but did you have the 'fittings' custom contoured, or are they off-the-shelf items?

The entire setup is off all of the following:
The chain
The hook
The charts

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
JETROASTER
The whole build will get broken down on the 'Max Heatgun, HRO' thread, but for starters...the housings are cocktail shakers. 1 right-side up, the other, upside-down. No custom fab work at all. Lowes, Target, Grainger. That's it. 1 drill press, 1 dremel.
...More to come -Scott
Edited by JETROASTER on 03/04/2011 1:00 PM
 
greencardigan

Quote

freshbeans wrote:No custom fab work at all. Lowes, Target, Grainger. That's it. 1 drill press, 1 dremel.
...More to come -Scott

That sounds like me. I'm loving it!! ThumbsUp
 
DavidG
Way to go, Scott!! She (he?) is GORGEOUS!!


DG
europiccola | yama + coryrod | chemex | AP | clever
wbp1 | wepp1 | bm/hg | co hybrid (still coming soon...)
 
JETROASTER
You're all very kind!!
....Sadly, not enough heat. Back to the lab.
Hopefully, a couple snips will do the trick, then back to testing. Cheers,-Scott
 
JETROASTER
Well, before I start snipping nichrome, I'm taking a step back. The heating coil is designed to deliver 650f at 40 cfm. If I'm not getting my temp, it's probably just too much airflow.
It fluidized 2 lbs, so i think that's a bit excessive. I only intended a 1 lb machine.
I've already added restriction to the distributor/perf, now I'm going to add adjustable restriction to the blower intake port. Naturally, that will recieve a gauge to go with it!!
With a bit of luck, that should tune this motor down to 40 cfm at a respectable pressure.

Any good (read cheap and easy) way to measure CFM? Thanks,-Scott
 
Unta
whats the diameter of the shaker?
sean
Sean Harrington
educate.
 
seedlings

Quote

freshbeans wrote:
Any good (read cheap and easy) way to measure CFM? Thanks,-Scott


ecx.images-amazon.com/images/I/413FNP8CS2L._SL500_AA300_.jpg

With this you'd know the speed of the air flow, then multiply the speed by the area of your opening:
http://www.amazon...amp;sr=8-1

SCFM = V*A
where V is average velocity (feet per minute) and A is cross sectional area of duct (square feet)


CHAD
Edited by seedlings on 03/07/2011 11:01 AM
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
JETROASTER
Barely 5" This looks like the same one. 29.99ea @ Target.
I found nno US made sub:|
http://www.google...DcQ8wIwAg# -Scott

....Thanks Chad!!
Edited by JETROASTER on 03/07/2011 11:06 AM
 
JETROASTER
From the 'Max Heatgun HRO' thread;

Quote

allenb wrote:

Were you successful with gaining more heat from your element?

Allen


Allen, the heat; I've tuned the motor in at 18" lift on the intake side, leaving me with 10" of pressure @ the plate. (11.5" with heat). It's just above minimum fluidization velocity. I've got 375f throughout the RC (no beans).
.....So that's it, after this test, I'll have to snip to get more heat. I really am shooting for things to be as 'off the shelf'
as possible. So I'll tinker a bit more before snipping.
On the topic of my goof-ups, I'll try to keep all the experiments on this thread, leaving the other a bit cleaner.
Tomorrow ....beans. -Scott
Edited by JETROASTER on 03/08/2011 8:14 AM
 
JETROASTER
Is it possible that pressure drop is killing my temps?
I'm going from roughly 12" column below the distributor, to 2" column above the distributor.
Boyles Law? Thanks, -Scott
 
jm82792

Quote

greencardigan wrote:

Quote

freshbeans wrote:No custom fab work at all. Lowes, Target, Grainger. That's it. 1 drill press, 1 dremel.
...More to come -Scott

That sounds like me. I'm loving it!! ThumbsUp

My kind of simplicity !
 
Unta
could you explain how you understand boyles law to apply to this machine...
sean
Sean Harrington
educate.
 
JETROASTER
Hi Sean,
Air below the perf is being heated under pressurized conditions. As the air passes thru the perf, it enters a lower pressure zone. If I understand correctly, as the pressure drops, so drops the temp.
I think that's how refridgeration works.
Certainly, those pressures are more dramatic, but I think the principle applies.

I am planning on reducing the differential between the upper and lower chambers, then add some restriction above the beans to tune the airflow back down.

We'll see..... -Scott
 
Unta
a fun visual rep of boyles law here http://www.grc.na...boyle.html

I agree with your idea, more pressure = more heat. I think Chad and David both have air restriction added to the tops of their machines.

Learn learn learn...
sean
Sean Harrington
educate.
 
seedlings

Quote

Unta wrote:
a fun visual rep of boyles law here http://www.grc.na...boyle.html

I agree with your idea, more pressure = more heat. I think Chad and David both have air restriction added to the tops of their machines.

Learn learn learn...
sean


I do put a plate on top of the hopper, but it doesnt' seem to further restrict air flow It keeps the air above the beans warmer.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Unta

Quote

seedlings wrote:


I do put a plate on top of the hopper, but it doesnt' seem to further restrict air flow It keeps the air above the beans warmer.

CHAD

no air restriction? isnt that what the plate is doing? Plate on top is restricting air, which is building pressure below and increasing temp of the air above the beans? I'm running on limited shut eye so I might have missed some thing here..
sean
Edited by Unta on 03/09/2011 4:14 PM
Sean Harrington
educate.
 
coffeeroastersclub

Quote

freshbeans wrote:
Hi Sean,
Air below the perf is being heated under pressurized conditions. As the air passes thru the perf, it enters a lower pressure zone. If I understand correctly, as the pressure drops, so drops the temp.
I think that's how refridgeration works.
Certainly, those pressures are more dramatic, but I think the principle applies.

I am planning on reducing the differential between the upper and lower chambers, then add some restriction above the beans to tune the airflow back down.

We'll see..... -Scott


Scott,

Another variable to add to the equation is that the air is losing temp as it passes through the perorated plate due to the fact that the plates mass is sucking heat from the air. B)

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
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