Trick to lowing the drum temp after first batch of the day?
I just began roasting on a Ambex Ym-2. In order to keep the smoke down i need to limit batches to 3lbs or less. I've noticed getting a bean turn temp closer to 150 degrees makes for a better roast. The problem I am running into is that after the first roast is done and i drop the fresh roasted beans into the cooling tray, the roaster is still too hot for me to drop the next batch. Do i just shut the heat off and let it slowly cool or am i pretty much hosed because of the batch size? Thanks.
02-03-2013 11:40 PM
I'm sure you'll be able to continuous roast once the routine gets comfortable. Not familiar with the ym2 but in order for members to help some more details would be helpful. What temp. Are you dropping in, drying time, ramp to 1c, roast development time, roast finish temp and time. Ive heard some Ambex users leave the air on the same setting without change; what are your air settings?
What temp is it climbing to after you finish your roast? What temp do you have your watlow set at to kill the burner?
"Wine is for aging, not coffee."
Ken Hutchinson, Starsky and Hutch
The Lovely & Talented Roast Mistress suggests:
~Kill the burner the second you drop the beans into the cooling tray
~Open your air control valve to 100% open
~Leave the hopper door (the opening where you drop the beans into the drum) open
~Prop the door on the drum where the hot beans come out into the cooling tray ALL THE WAY open
Your temp will come down pretty quick.
Wrinkles only go where the smiles have been -- Jimmy Buffett (via Mark Twain)
Expact is close. To cool the roaster down to your desired pre heat temperature quickly after the previous batch has been dropped into the cooling bin you will need to immediately turn the burner off by simply re adjusting your setpoint temperature on the Watlow controller to your desired pre heat temperature.
There is not an air adjustment on the Ambex ym-2 except for the damper to divert the air through the cooling bin. You will obviously need to have that damper in the cooling position if you just dropped your roast into the cooling bin so that will hinder your internal drum temperature decent slightly. Keep all of your green drop doors and roasting drum drop door CLOSED. To cool the inside of the drum fastest you need to pull cool atmospheric air through the roaster. If you open these doors you are literally pulling air into that door and directly into the exhaust system and out the stack. You will not pull air through the drum and surrounding mass.
When you open these doors tricks you by dropping your temperature read out rapidly. But as soon as you close the door, the temperature climbs back up.
Once your coffee in the cooling bin is cool divert your air back to the drum.
Also, if this is an older ambex roaster and there is a fighter jet looking switch labeled 'manual' make sure it is off at all times. It manually overides the setpoint controller and will leave the burner on with no high limit until you shut it off. I would only use the setpoint controller to control the burner.
Last edited by Lumberjack; 02-08-2013 at 12:29 PM.