Coffee beans contain components that are soluble in water and others that are not. Instant coffee is produced by dissolving the soluble portion in boiling water(i.e by making coffee) in large percolators, then feeding the coffee to a spray dryer in which the water is evaporated, leaving the soluble coffee to as dry powder. The insoluble portion of the coffee beans (the spent grounds) passes through several drying operations, and the dried grounds are either burned or used as a landfill. The solution removed from the grounds in the first stage of the drying operation is fed to the spray dryer to join the effluent from percolators. A flow chart of this process is shown below. The symbols S and L denote the soluble and insoluble components of the coffee beans, W is water, and C is solution containing 35 % S and 65 % W by mass.
(a) calculate the flow rate (kg/hr) of each stream 1 to 8.
(b) If the liquid effluent from the press could be fed to the spray dryer without afffecting the tasteof the product, by what percentage would the production rate of instant coffee be increased?