Java Master 2002 Coffee Roaster
Description
This is a Java Master 2002 fluid bed coffee roaster, capable of roasting up to 3.5 lbs green beans per batch.
Roast Profile
Roasting is determined by two parameters: hot air temperature and bean temperature. Hot air temperature is set on the left PID controller. It is a function of the bean weight, and is the temperature of the air entering the roast chamber. Target bean temperature is set on the right PID controller, and corresponds to the temperature of the air exiting the chamber. When this temperature is reached, the machine begins its cool down cycle.
Hot air temperature range is 530-575 F on the controller. For 1-2 lbs, it should be set close to 530 F. For 2-3.5 lbs, it should be set between 540-560.
Target bean temperature can be set between 370-445 F. This parameter determines the darkness of the roast.
Suggested roasting parameters will be listed here as more data is gathered.
List of Currently Authorized Users
Qualified Member | Trained By | Date |
---|---|---|
Theo Tetzlaff | Owner | |
Ryan Pierce | Danger Committee | |
Carl Karsten | Danger Committee |
Green Coffee Bean Suppliers
- JavaMaster - Sells in 3.5, 10, and 40 lbs quantities
- Sweet Maria’s - Sells in 1, 2, 5, 10, and 20 lbs quantities
Maintenance
Task | Date | Done by | Notes |
---|---|---|---|
Clean two exhaust thermocouples | 10/26/23 | Ryan | |
Clean glass chamber | 10/24/22 | Theo and Ryan | Spot cleaning only |
Clean upper duct | 10/24/22 | Theo and Ryan | Spot cleaning only |
Vacuum clean air intake filter | 10/26/22 | Ryan | |
Clean lower dump valve | 10/24/22 | Theo and Ryan | Spot cleaning only |
Clean hot air thermocouple | 10/26/22 | Ryan |
Technical Details
The roaster uses a Watlow PID controller (on the left) to control air temperature. It outputs a process value (4-20 mA), which an Avatar Instruments power controller uses to change the power to the heater via SCR phase dimming. The Avatar supports 240 V but the heater itself only can handle 208 V. This machine was designed to operate on 208 V but JavaMaster confirms it can operate on 240 V with an adjustment. Originally, JavaMaster suggested we limit the PID to 70% max output power. But that resulted in unexplained oscillations in temperature typically +/- 30 F. The Avatar includes an optional feature to limit output voltage via the V-LIM trim pot. This was adjusted so 100% on the PID corresponds to 208 V as measured by a true RMS voltmeter. Moving this back to 208 V will require re-adjustment of this trim pot.