PROCEDIMIENTO DE EXTRACCION DE BITRARTRATO DE POTASIO A PAR-TIR DE UNA SOLUCION CALIENTE PROCEDENTE DE ORUJO O MOSTO DE UVAS

摘要

A process and an installation for the extn. of potassium bitartrate from hot grape must, pressed marc extract, secondary wines etc. The process is of the type in which the soln. is cooled to crystalise the bitartrate. A crystalliser vessel is used in which a reduced pressure is maintained above the level of liq. in the vessel. Hot soln. injected into the vessel is subjected to adiabatic expansion leading to partial evapn. of solvents, cooling of the remaining soln. and crystallisation of bitartrate. The crystals settle in the bottom of the vessel from which they are extracted for washing and drying. Evaporated solvents from the head of the vessel are pref. condensed in an indirect heat exchanger if they contain alcohol and in a spray condenser if they do not. Incoming hot soln. is pref. mixed with cooled liquor drawn from the central zone of the vessel. The mixt. is recycled into the vessel at a level just below the surface of liq. in the vessel. Previous crystallisers for this type of work have suffered loss of thermal efficiency as encrustation of crystals have built up on heat transfer surfaces. This has previously been overcome by scrapers and stirring blades but this troublesome soln. has now been superseded.