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Cooling problems on a clean machine?

PostPosted: Fri Jul 02, 2010 7:25 am
by Oliver
I've been a little confused about the consistent problems of cooling our coffees in the cooling tray after we go through major cleaning, which happens once a month.
Shouldn't the coffee cool quicker?
It adds maybe two more minutes to cooling on our Diedrich IR-12, after about 3 days of roasting it goes back to normal.

Can anyone explain this to me or experienced the same thing?

Re: Cooling problems on a clean machine?

PostPosted: Fri Jul 02, 2010 10:00 am
by PatrickSmith
I am on a 12K as well, though it is a "U.S. Roaster" & has an independent cooling fan & exhaust pipe. My experience is more consistent with intuition, that is, I cool about 30 seconds to a minute faster after a thorough cleaning. I know from working on a Diedrich that the 80/20 airflow damper can accumulate a good amount of buildup in a month. Could it be that the buildup actually changes that ratio....say 90/10 such that more air is being pulled down through the cooling tray when the damper is "dirty"? That's a genuine question--not a statement. Interesting observation.

Re: Cooling problems on a clean machine?

PostPosted: Fri Jul 02, 2010 10:21 am
by Oliver
Could it be that the buildup actually changes that ratio....say 90/10 such that more air is being pulled down through the cooling tray when the damper is "dirty"?
That's what my thoughts are too, but we clean the damper every week. This issue is happens when we take the exhaust system apart and scrape from every pipe on towards the afterburner. The air flow damper is always kept very clean.

Re: Cooling problems on a clean machine?

PostPosted: Tue Jul 13, 2010 1:17 pm
by Jason Haeger
Oliver wrote:
Could it be that the buildup actually changes that ratio....say 90/10 such that more air is being pulled down through the cooling tray when the damper is "dirty"?
That's what my thoughts are too, but we clean the damper every week. This issue is happens when we take the exhaust system apart and scrape from every pipe on towards the afterburner. The air flow damper is always kept very clean.

Too big of an exhaust pipe can create back-pressure, interestingly enough.

Too small, and it's too restrictive. There is an ideal range of diameters for exhaust ducting keeping maximum airflow efficiency in mind.

It's also possible that there are air flow leaks that are sealed with the bits collected in the first couple of weeks.

Just a couple of thoughts that remind me of my days on car forums.