This is an idea for a way to manufacture soluble coffee
powder (aka instant coffee) faster, and possibly more
cost-effectively. By reducing the dwell-time of the
coffee in the machine, production can be faster, or the
floor space required by the machine reduced.
First, brewed coffee is frozen
in a manner which
produces appropriately sized granules.
The frozen coffee particles are transferred to the
bottom of a vibratory-type fluidized bed, which in turn
is inside of a pressure vessel (vacuum chamber).
Gas (mostly steam, but some air) is removed from the
bottom of the bed, via a gas compressor, into a heat
exchanger. The output from the heat exchanger goes
into a gas/liquid separator, with the water being
removed via condensate pump, and the gas removed
via a vacuum pump.
A separate flow of gas, also taken from the bottom of
the bed, is moved via blower through the heat
exchanger, and is introduced to the top of the fluidized
bed. The gas now heats the frozen coffee particles,
causing sublimation of the water within those particles.
The vibration keeps coffee particles separated from one
another, and sorted by density, which is determined by
how much water each particle has. Lighter, dryer
particles, naturally rise to the top.
Dry coffee granules are removed from the top of the
fluidized bed, moved to atmospheric pressure, and sent
I realize that gas flow is the opposite direction of what
it would be in a normal fluidized bed. However, gas
flow should be low enough that the vibrator will keep
the frozen coffee bits fluidized in spite of it.