Recovery of aroma gases

Apparatus for recovering aroma constituents from an aroma-containing gas given off during the processing of a beverage, which comprises

• a cryogenic collector having a sidewall with gas inlet means, a topwall with gas outlet means, and a bottom wall having a particle discharge opening extending therethrough,
• at least one porous cylindrical filter means mounted in said chamber intermediate the gas inlet means and the gas outlet means,
• means for introducing an aroma-containing gas through said gas inlet into said collector toward the vertical midline of said collector,
• means for introducing a liquefied gas into said aroma containing gas in the collector to cool the aroma gas to a temperature at which aroma frost particles are condensed from the aroma gas and the liquefied gas is volatilized to form a suspension of aroma frost particles in the gas,
• means for moving the suspension through said filter means whereby the aroma frost particles are retained on the surface of said filter means and said volatilized gas passes through the filter means and is discharged from the cryogenic collector through said gas outlet means,
• back pulsing means associated with the filter means for generating pulses of backflushing gas to dislodge aroma frost particles from said filter means, and
• means for recovering the aroma frost particles.