METHOD OF PREPARING TAR SUITABLE FOR MEDICAL PURPOSES Russian patent published in 2000 - IPC

FIELD: medical industry. SUBSTANCE: birchbark raw tar is poured into airtight distillation container which is heated through walls. Decomposition products are cooled and liquid fractions are separated. Distillation is carried out by gradual heating from 70 to 280 C. Average heating rate is 0.7 deg/min at temperatures varying from 70 to 170 C, and is 1 dwg/min at temperatures varying from 170 to 280 C. Volume of raw tar being poured into container does not exceed 50% of volume of container. Temperature of decomposition is controlled both in distillation container and drain pipe. EFFECT: preparation of conditioned medical tar and greater reliability and safety of the process. 1 ex