METHOD FOR PURIFYING DIFFUSION JUICE Russian patent published in 1997 - IPC

FIELD: sugar production. SUBSTANCE: proposed method for purifying diffusion juice employs semipermeable microfiltration membranes. Membrane microfiltration process is carried out after second carbonization, before evaporation, in closed circulation circuit, without access of air to juice. Microfiltration membranes let pass into filtrate all substances, molecular weight of which is less than that of saccharose or equal to it. In this manner, saccharose is accumulated in filtrate, while in concentrate remain all substances, molecular weight of which is greater than that of saccharose, i. e. in concentrate remain high-molecular colloidal substances, microorganisms, suspended matter and dyeing substances. After membrane filtration diffusion juice has high-yellow color; it is transparent and sterile. Membranes are regenerated without stopping operation of membrane units. Use of microfiltration membranes for purifying diffusion juice offers number of advantages: juice is purified from suspended matter and microorganisms by 100%, from high-molecular compounds and colloidal substances by 86-100%, including dyeing substances which belong to high-molecular and colloidal substances, purification from dark-coloring dyeing substances being 100%. EFFECT: juice quality is improved, on an average, by 1.7-2.1 units. 1 tbl