Underneath each drum is either a set of (3) 500 Watt halogen heat lamps, or gas burners, providing the equivalent of 5,500 BTU's per drum.
The drum temperature is regulated by a digital thermostat. The rate of temperature change can be altered by adjusting, the individual air and gas flow controls.
AIR FLOW CONTROLS
The cyclone (SINGLE DRUM CYCLONE LEFT) removes chaff from the roasted beans as they are emptied on to the cooling tray, along with exhaust gases, from underneath the drum area, during roasting. It is important to leave the cyclone on during roasting, because the vacuum it creates, affects the temperature settings.
IMPORTANT INFORMATION IN SELECTING A SAMPLE ROASTER-
COFFEE PRO SAMPLE ROASTERS ARE AVAILABLE WITH GAS OR ELECTRIC, AS A HEAT SOURCE,
NATURAL GAS OPERATES AT A LOWER PRESSURE THAN PROPANE GAS, AND WILL REQUIRE AN ADJUSTMENT TO THE GAS SUPPLY ORIFICE, IN ORDER TO PROVIDE THE CORRECT FLAME. A LICENSED GAS FITTER OR PLUMBER WILL BE ABLE TO DETERMINE THE CORRECT ORIFICE SIZE, BASED ON YOUR DELIVERY PRESSURE, THE BTU OUTPUT (5,500 PER BURNER) AND ALTITUDE. CHECK LOCAL CODES FOR PERMIT RESTRICTIONS, AS WELL AS PROPER VENTILATION REQUIREMENTS.
PROPANE OPERATES AT A HIGHER PRESSURE, AND THE EXHAUST IS NON TOXIC. HOWEVER, AN EXTERNAL PROPANE TANK MAY BE REQUIRED. CHECK LOCAL AND STATE REGULATIONS.
ELECTRIC HEAT IS PROVIDED USING 500 WATT HALOGEN HEAT LAMPS, READILY AVAILABLE AT A HARDWARE STORE. BECAUSE OF THE AMOUNT OF CURRENT DRAW, THEY REQUIRE 220 VOLT SERVICE.
The heavy steel alloy drums provide
even heating, and simulate roasting conditions in large scale roasters.
A damper valve may be used to help regulate the air flow.
Some beans produce more chaff than others, and may collect too quickly at the drum exhaust ports, restricting the exhaust flow, and causing over heating. Care must be taken to provide the right vacuum pressure, so that chaff is removed, but not too strong to interfere with the flame.
KEEP EXHAUST PORTS FREE OF DEBRIS
NATURAL GAS VS PROPANE
The gas supply orifices unscrew from the burner.
They are calibrated at the factory for propane gas.
For natural gas, which operates at a lower pressure, the orifices should be calibrated on site, by a licensed gas fitter/plumber, or contact Coffee Laboratory for replacement orifices. Be sure to have your gas pressure information handy
EXAMPLE: At 7" WC, and 5,500 BTU, AT SEA LEVEL,
THE DRILL SIZE USED TO CALIBRATE THE ORIFICE WOULD BE A #60
(SMALL DIFFERENCES CAN HAVE BIG RESULTS, SO BE SURE TO HAVE
A LICENSED GAS FITTER CALIBRATE THE BURNER ORIFICES)
"We have found the Coffee Pro to be a great sample/lab roaster. We have the twin drum propane unit and have found the samples we have put through the Coffee Pro to be very consistent giving us quite an accurate indication of the quality and characteristics of our samples. We shopped around before deciding on the Coffee Pro. The deciding factors were price/affordability, quality workmanship and simplicity of use. We are extremely happy with our Coffee Pro. Gavin Wilkinson - The Aussie Bean, Orange CA USA"