Issue link: https://read.dmtmag.com/i/491356
36 STiR tea & coffee industry international coffee storage and blending; grinders for any particle size; ground coffee stor- age and degassing with feeding system to the packaging machines. At company headquarters near Ferrara, Petroncini offers clients a state- of-the-art Technological Coffee Competence Centre. There, company engi- neers share knowledge and advice with established customers and too, new investors seeking to improve product standard or conduct new product trials. Learn more: www.petroncini.com STA Impianti What began as a startup venture in a Bologna garage in the 1980s has grown to an internationally known roasting equipment manufacturer. STA Impianti specializes in customized industrial coffee roasting plants controlled by semi- automatic, automatic and/or fully computerized systems. Its traditional roast- ers and patented STA clean-air roasting system machines operate worldwide. Capacities range from 2 kg/hour up to 3,000 kg/hour with a throughput of 4 to 6 cycles/hour. STA roasters employ user-friendly technologies for a simple turnaround in the roast profile. Temperatures can be fine-tuned to produce a range from the dark roast of southern Italian espresso to a German style roast and with a short change-over time. The company is currently highlighting its Millennium M.3 roaster, de- signed to maximize heat dispersion. The burner is separated from the roasting drum allowing hot air to enter the perforated roasting drum evenly from top The STA Impianti Millennium M.3 roaster. Types of Coffee Roasters There are the five major types of commer- cial coffee roasting equipment. Drum Roasters Most roasters consist of a horizontal rotat- ing drum with internal vanes or paddles that tumble the coffee. The coffee is heated indirectly from a source beneath the perforated or solid drum. Air Roasters Hot air roasters force a stream of heated air through a screen or perforated plate, suspending the beans mid-air in a vertical roasting chamber as they tumble in the heat. Also known as fluidized bed roasters. Packed Roasters Coffee is introduced to a vertical cone shaped spinning drum with paddles at the base. Beans bounce within the roasting chamber absorbing heat from the chamber walls and heated air. Centrifugal Roasters Coffee beans flow into a fast spinning bowl to form a vortex around a central column of hot air. Roasting time is under six minutes. Commercial versions roast 8,000 lbs. per hour. Tangential Roasters A high capacity vertical roasting chamber that remains stationary as rotating blades tumble coffee within. Roasting time is under eight minutes. Commercial versions roast 11,000 lbs. per hour. Heat Sources include natural gas, liquid petroleum gas, elec- tricity and wood. Green beans initially absorb heat but around 347 degrees the process become exothermic and the beans give off heat requiring rapid cooling. Beans are heated by one or more means: Convection Beans are surrounded by hot air Conduction Beans contact a hot surface Radiation Beans absorb infrared heat