Historical Context and Modern Technology

• Evolution from simple pans over hot coals/open fire to sophisticated automated machines
• Modern roasters: large, fully automated with built-in gas burners heating air for bean roasting
• Features: programmable and manually adjustable via touch panel
• Roast Master controls: temperature, roasting time to influence flavor, acidity, other characteristics

Roast Chamber Construction

• Material: stainless steel sheets fed through sheet metal roll
• Process: weld rolled sheet into cylinder → grind and polish welds until flat, smooth, shiny
• Function: drum where beans roast by convection heat

Cooling Tray Manufacturing

• Similar construction to roast chamber with support band welded to top
• Function: drum receiving hot beans from roast chamber
• Features: stirring arms circulate beans, fan draws air through tray for cooling

Stainless Steel Component Fabrication

• Material choice: stylish, durable, corrosion resistant
• Computer-guided laser cutter: slices safety components (heat shield)
• Heat shield: prevents roast master burns
• Precision forming: press brake creates angles and curves
• All parts require very precise shaping

Trier Component Construction

• Function: draws bean samples during roasting
• Construction: welding smaller parts to stainless steel tube
• Finishing: meticulous grinding and polishing of welds until smooth

Flight System Manufacturing

• Pressure water jet cutter: cuts 6 flights from stainless steel sheets
• Flights: part of paddle lifting and mixing beans in roast chamber
• Forming: individual curving in press
• Assembly: specialized fixture positions components correctly
  • Align spokes to paddle shaft
  • Weld parts in place
  • Clamp and weld flights securely

Paddle Assembly and Precision

• Inner and outer flights: lift beans into airflow for even roasting
• Custom grinding machine: hones flights for ~0.1 inch clearance between paddle edge and roast chamber wall
• Design ensures: paddle wide enough to pick up every coffee bean

Chamber Assembly

• Face plate installation: closes roast chamber with alignment pins
• Paddle shaft: protrudes through bearing in face plate
• Hoist system: lifts heavy chamber onto stainless steel support frame
• Heat shield installation: laser-cut and press brake-shaped component

Hopper and Feeding System

• Funnel-shaped hopper: feeds unroasted coffee beans
• Vacuum system: lid tube connects to vacuum drawing beans through plastic hose
• Hinged discharge door: front-mounted with viewing window

Temperature Monitoring System

• 4 total temperature sensors sending data to computer:
  • Bean temperature in roasting chamber
  • Air temperature entering roast chamber
  • Air temperature exiting roast chamber
  • Clean air temperature after burner incinerates smoke

Cooling System Installation

• Cooling tray: beneath discharge door on support frame
• Motor: turns stirring arms inside tray
• Cooling fan and cage: measures air pressure mixing with gas to burner

Air Circulation System

• Circulation fan: withstands high heat, moves air efficiently
• Vacuum motor: bottom of stainless steel tube
• Connection: top end to feed hopper lid tube
• Process: vacuum sucks raw green beans into hopper → drops into chamber

Chaff Separation System

• Cyclone separator: connects to circulation fan
• Process: fan blows hot air from roasting chamber into cyclone at high velocity
• Air circulation: downward spiral past burner at cyclone base
• Functions: incinerates smoke, draws chaff into barrel
• Safety: water nozzles spray chaff preventing fire (common hazard in traditional roasters)
• Clean air return: regulation fan forces clean hot air through S-shaped insulated duct back to roasting chamber

Electrical Control System

• Control panel assembly: factory electrical department
• 6 electric motors controlling:
  • Bean drawing vacuum motor
  • Circulation fan
  • Cooling tray fan
  • Roasting chamber paddle
  • Cooling tray stirring arms
• Installation: control panel in side cabinet, computer adjacent to cabinet
• Wiring: complete connection of all electrical components

Cooling Tray System Operation

• Motor drives stirring arms under tray
• Hot beans sit on stainless steel screen
• Cooling fan: pulls ambient air through beans → down through screen openings → out exhaust pipe outdoors
• Stirring arms: move beans for quick, even cooling preventing continued roasting

Quality Testing Process

• Multiple test roasts on every finished roaster
• Operator process:
  • Heat roast chamber to specific temperature
  • Use touchscreen to release beans into chamber
  • Hot air circulation: cyclone → roast chamber → return pipe → cyclone (cleaned) → back to chamber
• Manual monitoring: operator views, smells, listens to beans
• Bean indicators: crackling noises as beans expand and shed chaff
• Automatic option: machine ends roast cycle when beans reach target temperature
• Cooling process: trapdoor opens for ambient air → pushes smoke to cyclone for incineration
• Discharge: automatic or manual door opening → beans drop to cooling tray → stirring arms and cooling fan auto-start
• Quality check: perfectly roasted beans indicate machine ready for shipment