Abstract:
Coffee is one of the world’s most popular beverages and its processing involves distinct
operations: planting, harvesting,sorting,drying, roasting, grinding and packing. Among these
processes the roasting process is extremely crucial for the quality of the final coffee aroma.
Roasting presents the key step in coffee processing to develop the characteristic flavor
properties for which coffee is appreciated. In addition, roasting induces major physical
changes within the coffee beans and determines their behavior in storage, grinding, and
brewing. The impact of the roasting parameters roasting time, roasting temperature,
moisture content, quenching method, and roaster design, on aroma formation, aroma
stability, and grinding properties of roasted coffee were a very important things to
investigate for better economical and customer satisfaction. Since the existing roasting
machines are not fully capable of obtaining the desired quality and depending on their
source of energy, therefore in order to obtain the mentioned merits to fulfil the demands
satisfaction it is needed to design the rotating drum type coffee roasting machine to keep in
touch the specific desires of this thesis accordingly. The beans are roasted for a period of
time ranging from a few minutes to about 30 minutes and the roasted coffee would be packed
in order to keep its aroma and quality The general objectives is design and modelling of
rotating drum type coffee roasting machine using LPG as a source of energy and the system
uses atmospheric burner which is placed outside underneath of rotating drum. The
methodology of working is, the drum type coffee roasting machine is typically horizontal
rotating drums that tumble the green coffee beans in a current of hot burner flame and very
important roaster that it keeps the uniformity and homogeneity of roasting. At the end of the
roasting cycle, water sprays, fan and air are used to "quench" the beans. In conclusion, the
study would yields economical, easily operated and maintainable roasting machine to obtain
the crucial and valuable flavor of coffee aroma with high quality.
