HomeRoast Digest


Topic: Drum roaster fan (8 msgs / 185 lines)
1) From: Irene and Lubos Palounek
This may reveal my ignorance related to coffee roaster design -- but I need
to ask: which way should a drum-roaster fan blow the air?  Should it suck
fresh cool air inside the roaster, or blow out the hot air from the roaster?
I can think about arguments supporting either possibility. There is a filter
on the right side of the HotTop; is it there to filter out the smoke from
the air being blown out, or to prevent some insects or dust to be sucked
into the unit?
I would consider our HotTop drum roaster to be one of the "hot running"
units.
This evening, I roasted 302.4g of green SM Monkey Blend beans and ended with
242.3g of beans with oil on the surface; that is almost 20% loss of weight.
From my previous experience, I expected that some of the oil will get suck
back into the beans. The beans are now in a vacuum canister, in the "Tilia"
vacuum.
I put a candle next to the fan on the right side of the roaster. When the
unit turned its fan on, I watched the flame; it seems that the fan sucks the
cold air into the unit. Is that what it was designed to do, or is it wired
the wrong way? How do I tell for sure whether the fan works as intended? I
am afraid that the "candle flame" method is not very reliable when used
outside; I am not sure which way the fan blows the air.
Here are some times of that roasting session, outside in a "Texas cool"
evening, 69F at seven o'clock in the evening, about 50% R.H.
The roaster preheated for four minutes and thirty seconds; that's when I put
302.4g of green beans into the HotTop and measured time from that moment.
HotTop TEMPerature Level 5
00:00	Beans in, fan on
00:50 fan off
07:00 "bread-like" smell, extremely light tan color
11:30 fan on
14:30 light brown
16:00 First Crack
17:00 unit beeps
      - pushed the "PLUS" five times total
18:00 rolling Second Crack
18:30 manually eject - oily beans come out into the cooling tray
I am afraid that this time I roasted the Monkey Blend a little more into the
Second Crack that I wanted. I will know the taste in couple of days.
Regards, Lubos
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

2) From: Dan Bollinger
Lubos,  I haven't seen a HT, but I'm going to take an educated guess and say
the fan blows air into the chamber and the 'filter' is really a chaff
collector.
Which ever way the fan is blowing is the right way. Fan motors on roasters
are AC devices and not polarized.  Switch the wiring and the fan still runs
in the same way! Therefore, it is impossible to wire them wrong.  Dan
<Snip>
need
<Snip>
roaster?
<Snip>
filter
<Snip>
with
<Snip>
weight.
<Snip>
"Tilia"
<Snip>
the
<Snip>
put
<Snip>
the
<Snip>
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

3) From: AlChemist John
Sometime around 05:58 10/10/02, Dan Bollinger typed:
<Snip>
And here I thought I got really lucky when I re-wired my WBI and couldn't 
remember which wire went on which pole.  Oh well.
Never send a chemist to do an electrian's job.
--
John Nanci 
AlChemist at large
Roasting and Blending by Gestalt
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

4) From: EuropaChris
On the HT, the fan sucks air OUT of the roaster.  The filter is a joke of an attempt at smoke control.  The chaff falls into a tray below the drum.  
That's one strike against the HT vs. the Alp.  The Alp directs smoke quite well out of the 'chute' on the end, allowing easy venting.  The HT leaks smoke like a tire fire, and really stinks up the joint if you try to roast inside.
Chris
"Dan Bollinger"  wrote:
<Snip>
The NEW Netscape 7.0 browser is now available. Upgrade now!http://channels.netscape.com/ns/browsers/download.jsp
Get your own FREE, personal Netscape Mail account today athttp://lists.sweetmarias.com/mailman/listinfo/homeroast">http://webmail.netscape.com/homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

5) From: John
Lubos,
My HotTop exhaust fan kicks on with enough force that there is no
mistaking its direction. The fan does not run all of the time, but is
very much in evidence at the peak of the roast.  The air flows from the
grill in the top of the unit through the drum and out the back (or right
side)  I roasted 250g of Tom's Monkey Blend when I first got the unit
and ran it on level 6. I had light oil on the beans that remained. The
coffee made a great shot.
On Wed, 2002-10-09 at 21:26, Irene and Lubos Palounek wrote:
<Snip>
ed
<Snip>
er?
<Snip>
ter
<Snip>
ith
<Snip>
t.
<Snip>
ck
<Snip>
a"
<Snip>
the
<Snip>
d
<Snip>
I
<Snip>
put
<Snip>
the
<Snip>
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

6) From: Dan Bollinger
Chris and Lubos, I stand corrected!  Good thing I quailifed my statement.
What a poor design running smoke over a fan blades.  Cleaning them will be a
maintenance item. Dan
<Snip>
say
<Snip>
roasters
<Snip>
runs
<Snip>http://webmail.netscape.com/<Snip>">http://channels.netscape.com/ns/browsers/download.jsp<Snip>http://webmail.netscape.com/<Snip>
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

7) From: EuropaChris
Well, yeah, it's a maintenance item, but no different than a commercial roaster.  They all have fans that pull the smoke out of the drum and out the vent.  Cleaning all the 'gook' is a regular task unless you want a roaster fire.
Chris
"Dan Bollinger"  wrote:
<Snip>
<Snip>
The NEW Netscape 7.0 browser is now available. Upgrade now!http://channels.netscape.com/ns/browsers/download.jsp
Get your own FREE, personal Netscape Mail account today athttp://lists.sweetmarias.com/mailman/listinfo/homeroast">http://webmail.netscape.com/homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

8) From: Rick Farris
Lubos wrote:
<Snip>
In general, in electronic equipment, fans are oriented to exhaust hot air.
If the fan was used on the intake, it would add it's own heat to the air
going into the equipment; a bad thing.  Fans are somewhat easy to replace
while electronic innards, aren't.
But in a roaster, where heat is a good thing and where the exhaust air is
*extremely* hot, the fan is placed on the intake, where the incoming cool
air can keep the fan cool - extending its life - and the heat from the fan
motor adds to the roasting heat.
-- Rick
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast


HomeRoast Digest