GB298214A - Improvement in process of refining rosin - Google Patents

Abstract

298,214. Hercules Powder Co.., (Assignees of Langmeier, A.). Oct. 6, 1927, [Convention date]. Resins.-Resin is refined by flowing molten resin over a heating surface while flowing a heating medium in an opposite direction relatively to the surface, whereby the resin is subjected to an increasing degree of heat. The resin is melted at a temperature sufficient to vaporize its component of low volatility in a predistiller, the resin being finally vaporized in a vaporizer and the vapours condensed to provide high grade resin and resin oil. The process is preferably effect-ed under reduced pressure and in the presence of superheated steam. In an apparatus suitable for carrying out the process, low grade resin is melted in a pot 2 by a steam coil and the molten resin is forced by a pump 10 into the inner tube 14 of a pre-distiller. Herein the resin is heated by oil entering and leaving by the pipes 18 and 20 respectively, to a temperature between 464- 500‹ F. to vaporize any low-boiling colouring matters. Vapours and unvaporized resin leave by a pipe 22 and enter a separator 24, where the vapours are separated and leave by a pipe 26 to a condenser 28. A vacuum pump 30 maintains the separator, condenser, and pre-distiller under a reduced pressure such as “-5 inches of mercury. The unvaporized resin passes through a pump or feed-cock 34 to the inner tube 36 of a vaporizer 38, similar to the pre-distiller and heated by oil entering its outer packet at 40 and leaving at 42. That part of the resin which can be distilled without decomposition is here vaporized, preferably at about 500-575‹ F. The mixture of resin vapour, unvaporized material, dark low volatiles, &c. pass into a separator 46, where the liquid material is .separated from the vapours, a low grade resin being recovered from the outlet 56. The vapours pass into a condenser 50 or series of such condensers maintained at decreasing temperatures. High grade resin condensed is drawn off through an outlet 54, and uncondensed vapours pass off through outlet 52 to a condenser and scrubber, which may include a circulating stream of solvent to dissolve resin and resin oil. The scrubber is connected to a vacuum pump to maintain a pressure of about “-2 inches of mercury throughout the vaporizer system. Steam, superheated at 60, by oil returning from the pre-distiller and vaporizer, passes into the pre-distiller and vaporizer through pipes 66 and 68. High-pressure steam, mercury. fused salts, or alloys may be used instead of oil for heating purposes. The Specification as open to inspection under Sect. 91 (3) (a) describes also the use of direct. heat for heating purposes. This subject-matter does not appear in the Specification as accepted.