Observations on the Resistance to Vertical Airflow of Green and Parchment Coffees

Abstract

Resistance to airflow data for seedlike products is necessary if drying and conditioning units based on the flow of air through the material are to be rationally designed. No such data were available for parchment coffee and green coffee beans. Suitable equipment for determining such data was constructed and the necessary data from a representative batch of each material were collected. Mathematical expressions relating the variables were determined using standard statistical methods. While a number of factors are known to cause a considerable variation in airflow through a given material, this has in no way reduced the value of airflow data in relation to installations for other grainlike products. It is therefore felt that the data obtained may be useful as a guide for those concerned with the design and operation of dryers and conditioners for parchment coffee and green coffee.