Kowshik Kumar Saha
Scientific Officer
Farm Machinery and Postharvest Process Engineering Division,
Bangladesh Agricultural Research Institute, Gazipur-1701.
M Ayub Hossain
Principle Scientific Officer
Farm Machinery and Postharvest Process Engineering Division,
Bangladesh Agricultural Research Institute, Gazipur-1701.
M Arshadul Hoque
Senior Scientific Officer
Farm Machinery and Postharvest Process Engineering Division,
Bangladesh Agricultural Research Institute, Gazipur-1701.
M Mohabbat Ullah
Principle Scientific Officer
Hill Agricultural Research Station,
Bangladesh Agricultural Research Institute, Khagrachari.
The transformation of the coffee cherry to a quality brew is complex and one of the most crucial transformations that takes place in the coffee grinding process. A power operated disc type coffee grinder was developed at Farm Machinery and Postharvest Process Engineering Division (FMPE) of Bangladesh Agricultural Research Institute (BARI) during 2010-2011. One of the major modification was the grinding disc was replaced by larger one. An electric motor of 0.37 kW was used to operate the machine. The speed of the rotating disc was 280 rev/min. The clearance between the static and rotating discs was 1-2 mm and it is adjustable with a knob so that it can grind the coffee to the desired fineness. The grinder was tested for grinding of roasted coffee in FMP Engineering Division, BARI, Gazipur and Hill Agricultural Research Station, Khagrachari during 2011-2012. The average capacity of the grinder was 13.5 kg/h which was 17.4% more than previous. The local and urban consumers were satisfied with the flavour and fineness of the ground coffee. The grinder should be demonstrated at farm level for its refinement and publicity.
Capacity, Coffee, coffee grinder, disc, hopper
Gazipur, Khagrachari
Farm Mechanization
(i) To design and fabricate a power operated coffee grinder
(ii) To test the performance of the grinder in laboratory and in the field
(iii) To Make an economic analysis of the coffee grinder
A power operated disc type coffee grinder was developed in Farm Machinery and Postharvest Process Engineering Division of Bangladesh Agricultural Research Institute (BARI) during 2010-2011. A few modifications were done to increase its efficiency according to the users demand during 2011-2012. Dimensions of some parts were reviewed and manufacturing faults were also identified. To increase the capacity of the grinder the larger grinding disc and auger were used without increasing the operating power. Diameters of the grinding disc and auger were 140 and 50 mm where previous were 120 and 38 mm, respectively. SS sheet was used as hopper material in case of plastic. The machine weighed about 25 kg. 10 kilograms of freshly harvested green coffee beans were collected from the coffee garden of Hill Agricultural Research Station, Khagrachari. Green coffee beans were roasted in a coffee roaster. Depending on roasting time and temperature, they were processed in three different degrees (light, medium and full roasted). After roasting the grinder was tested for grinding of coffee. To measure the moisture content of roasted coffee beans samples were collected. Three samples of 20 g of each type were placed in an oven at 105 °C for 24 hours. After 24 hours they were weighed and the moisture content were determined in dry basis. Several runs for grinding of coffee were carried out during April to June, 2012 at Farm Machinery and Postharvest Process Engineering Divisional laboratory and Hill Agricultural Research Station, Khagrachari of Bangladesh Agricultural Research Institute (BARI). Grinding data were collected for all three types of roast degree (light, medium and full roasted). The machine was tested with 2 kg of sample for each type of roasting and capacity was determined. Fineness of the ground product also observed during testing. The performance was also compared with the traditional method.
Research Report
(i) A coffee grinder was developed for grinding of coffee bean in household or small scale industry level.
(ii) The grinder was fabricated with locally available materials.
(iii) The maximum grinding capacity of the grinder was found 15.8 kg/h.
(iv) Cost of grinding of coffee by the coffee grinder was Taka 3.50 per kg.
(v) The use of the grinder would reduce the cost of grinding by 84.21%.
(vi) The performance of the grinder was satisfactory over the traditional grinding method.
Report/Proceedings, Booklet/Leaflet