topbanner.gif
Login
Username

Password




Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Shoutbox
You must login to post a message.

05/12/2021 12:52 AM
jrccole0112, Welcome !

05/11/2021 2:53 AM
Welcome, Frisky turkey & Robb77 !

05/08/2021 6:42 PM
Quidgybo Welcome! beach

05/08/2021 8:02 AM
Welcome, wcdyson !

05/02/2021 3:05 PM
Welcome espresoman

Community Spotlight
Brainiac
Join Date:July 27, 2007
Location:New Zealand
Posts Count:89
Rank:1/4 Pounder

Halogen Radiant Roaster
Hybrid Air Roaster
In Memory Of Ginny
Donations

Latest Donations
JackH - 25.00
snwcmpr - 10.00
Anonymous - 2.00
Anonymous - 5.00
Anonymous - 5.00
Users Online
Guests Online: 7

Members Online: 0

Total Members: 7,179
Newest Member: jrccole0112

View Thread

Who is here? 1 guest(s)
 Print Thread
Sucking and Blowing
Unta
Were talking air here people.. Anyone out there sucking? the RRob designs are exclusivly a push air through to loft the beans. I had started down that path, long before I had ever found this fine group of people here , with similar addictions and lofty aspirations (pun intended).With no scientific backing and just enough ignorance to start putting things together and tinkering around with parts i had in my basement. Though from my initial research into hot air fluid bed roasters, predominatnly the Sivetz site and the generous quantity of information that he provides. Along with the various patents and spin offs of his design. all of his roasters, aside from the very small heat gun roaster, all use Suction. Until I had discovered that suction helps with lofting, I had always just written its use off to smoke/ chaffe removal. Know after the success of the addition of suction to my Reddi Roaster I'm beginning to feel like the holy grail has been uncovered..My question to anyone out there who thinks about roasters is, are you using suction and why not if your not? This isn't meant to be told ya so commentary, I just would like to hear from other builders and roaster users, why they may or may have not considered it, and why they may or may not have chosen to head in that direction. also any of the engineers who might be abel to speak to the benefits or not of drawing air through a collection of beans versus trying to push air through.I look forward to hearing your comments.. My BEST to everyone.Warm regards..
Sean B)
Sean Harrington
educate.
seedlings
Sean, I hadn't considered suction as propulsion, although I had wanted to complete a roaster that recycles the hot air. You say Sivetz uses suction? I could've misread, but I was pretty sure any suction is just for the cyclone. From illustrations and videos it looks as if Sivetz burners fire into the blower inlets, but the air blows up through the bean mass.

So you're using two air sources, one blowing across heat, into the beans, the other source taking in exhausted hot air (and chaff)?

Sounds like innovation to me!

CHAD
Edited by seedlings on 04/13/2010 11:22 AM
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
Unta
You might be right, but its not one or other other with the reddi roaster its both in conjunction. I think if not on pourpose then by default mr sivetz is using the same principal.. ill have to go reread the patent...
Sean Harrington
educate.
endlesscycles
It's pressure differential that causes movement. Doesn't matter what the two pressures are, it's the difference that matters.
-Marshall Hance
Asheville, NC
Unta
Marshall, Great point..I guess the question really lay in what is most effcient use. greater pressure on the underside of the beans or greater pressure on the top side. I don think that one or the other is the best solution(my expirience/opinion). its a combination of both. I had read an article on the utilization of suction or blowing air for use in cooling of components in a small electrical device. the question was what was going to be better means to cool the device. There is no clear victor though some great conversation comes up..you can visit it herehttp://www.214m.c...10441.html .
atmosheric pressure comes up in this conversation as being = to 37feet of water. holy guacamole batman.. seems like anything we can do to lessn that is going to amount to a more efficient roast and use of BTU. BEST!Sean
Sean Harrington
educate.
endlesscycles
Pressure below minus pressure above is going to be equal for a given bean agitation no matter if you decrease pressure from above or increase pressure from below. This is simple Newtonian physics.

How the motor deals with heat is the main concern, IMO.
-Marshall Hance
Asheville, NC
Unta
for a given bean agitation? please explain..And i assume your refering to the minus pressure motor? sorry for being such a simpleton..;)

Sean Harrington
educate.
seedlings
I think Marshall might be trying to say that blowing 37f pressure OR sucking 37f pressure would produce the same result for a given amount of beans. However, you're doing both.

Sean, do you notice a "smoother" or "better" bean circulation?

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
Unta
yeah hes saying that moving beans would mean that presure has equalized on either side of the fluid bed... which is true in a perfectly balanced setup..its similar to what they try to do with a building HVAC system perfect balance. though they never get that either. though back toreddi roaster and the beloved empirical evidence, i dont believe the perfect balance to be evident with my current set up.. I think that it IS the eventual goal .. though i dont believe any of these machines are perfect.Which i think leads to his heating of the suction motor because its under restriction when its not functioning in its perfecct enviroment of very little restiction. I have noticed motor temps that heaqt up a bit, but im producing so much per roast that i havent run the unit more than 3 times consecutively.. though with the plans of expansion i think im going to be opening things up enough to get a little less top end pressure(suction with in the roasting chamber..) Ill see if i cant figure out a way to demonstrate what Im talking about with that .. anyone have any ideas how i migh be able to measure it..Water in the old inch tube hmmmm.. and please Marshal feel free to chime in.. i appreciate yours and anyone elses opinion on these matters. It great for the learning and growth end of this hobby..the reason i even bother to tinker in the first place..Thanks Chad..Best! sean

BTW Chad yes its a different type of movement, very active.As the beans expand they jam up inthe RC space and it becomes a very fluid consistent movement. im not sure again if its any different then RRobs unit. That has a very efficient/fluid movement also.But as you know with the blower that im pushing with im at an 18-1 pressure disadvatange..I believe. :)
Sean Harrington
educate.
Hamilton
you could just test it with coffee beans. If you can loft X coffee beans max with just a blower, but you can loft more than X coffee beans with a blower and a vacuum that should prove it.

I'm not sure exactly what Marshall was getting at, but I don't know that pressure differential is what you need to look at when lofting beans. Airflow and force are what lofts coffee. If you have a motor blowing air through the bottom of the bean bed, and another motor sucking air from the top, there will not be much pressure differential, but beans are going to move.

The other issue, is that reducing pressure inside the roasting chamber will make your roaster much less efficient with heat. I actually added a damper to my Rob roaster to help retain heat in the chamber. I have to turn the motor up slightly higher, but heat is the limiting factor in my roaster, not lofting power.
Tim
Unta
hamilton, I had a similar idea earlier about just doing a test with my exisiting blown air and adding the suction air to the bottom and see what the outcome is . My only problem is with my current set up i cant keep the fire going and move that quantity of air. I would need to update the burner and at this stage in my game it isnt an option. Thanks for the thoughts.Cheers!
Sean
Sean Harrington
educate.
seedlings
Sean, could you test without the heat on?

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
Unta
yeah definately,planning on it. Just the heat or the firing of the burner, does something to the air which enhances the loft.. not being a physicist I'm at a loss to tell you why. All I can say is that there is evidence supporting "the heat helps"theory, aside from the obivious change in the beans.. which is goal..HEHE.Grin..rain friday, ill probably get some time to play with the roaster a bit then. Ill be sure to let you know the results..Cheers!SeanB)
Sean Harrington
educate.
endlesscycles
It doesn't matter where you put pressure. It's the same either as a positive or a negative. It's simple physics, math, whatever. You get the same result either way. Can I say 1=1 twice? 0=1-1. There, I did it.

Newton: Three rules to rule them all.
-Marshall Hance
Asheville, NC
JETROASTER
The increased lofting is due to energy released during combustion. sucking or blowing.
Unta
thanks fresh..
Sean Harrington
educate.
Buildit
I hate to bring back an old thread, but it is the only one I could find with regard to lowering the pressure in the roast chamber. This is for a fluid bed / sprouted roaster.

Sean ( or anyone else) did you ever do anything with a suction fan after the roast chamber?

My reasons to ask.
it will reduce the pressure in the roast chamber = faster drying? but slower roasting because of fewer air molecules/ mm^3?
it would make my dump easier = from bottom rather than sucking them up a tube.
it will increase the temp in my cyclone = may or may not reduce smoke particles?
it may reduce the size of the chaf = finer dust +/-

But it is on the high temperature side = (high temperature fan mod)
it could foul more = coated (more than normal due to pressure change in fan)?
lastly I have never seen it done this way? so I would ask if any one has tried?
My biggest fear is that, due to the lower pressure, I could loose volatiles (flavors) in the roasting.
coffeeroastersclub
Hello. I hope everyone is well. I haven't posted here in quite a bit, been very busy with things. In any rate maybe an old thread I posted a while back can help you with your negative air pressure question. I designed and used a roaster that incorporated such a design a few years ago. Here is my thread on it, and it has some links to videos I made of the roaster:

https://forum.hom...post_63206

Len
Edited by coffeeroastersclub on 04/07/2020 8:47 AM
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
JackH
Hi Len, thanks for posting the link.
I am glad you are OK.
---Jack

KKTO Roaster.
coffeeroastersclub
Thanks. Just been flat out busy for quite a while. My wife and I started a new venture of soap manufacturing, and it along with our coffee roaster making business had gobbled up our time. Things are a bit slower on the coffee roaster making business right now due to the corona virus thing, however soap making is steady.

In any rate, I have no new roaster designs to report. I essentially now just roast outdoors in my grill with one of my 2 lb drums overfilled to 3 pounds. I use a 2 burner charbroil with a 6rpm-9rpm old char broil rotisserie. I get perfect roasts all the time with such a simple setup. I put 3 pounds of beans in my 2 lb capacity drum (drum is 8" long, 7.5" cage diameter). I then put the drum in the grill (not preheated), light the burners and turn them both to the highest setting. After I hear 1st crack I let it go for another 20 seconds then turn burners to medium low. I then let it continue till completion. Usually around the very start of 2nd crack.

Len rockon
Edited by coffeeroastersclub on 04/07/2020 2:24 PM
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
Jump to Forum:

Similar Threads

Thread Forum Replies Last Post
MCP3424 on TC4 blowing Dataloggers/Controllers/Rate of Rise Meters 9 05/07/2021 7:27 AM
Sucking the Smoke -- BM/HG indoors?! Building a Coffee Roaster 8 12/21/2010 7:51 PM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion Copyright © 2021 PHP-Fusion Inc
Released as free software without warranties under GNU Affero GPL v3
Designed with by NetriX