Document 2G6K7Jvy2j23vOvMLOj5ZJRN

summer . POWERFAX 19 3 2 vacuum 0)LstillatLori {Editor's Note--This article is abridged from articles on Wet and Dry Distillation Processes written by Mr. Fomcrook for Refiner and Natural Gasoline Manufacturer, andprinted in their February, 1982, Process number. Reprints of the original articles are acailable and will gladly be sent to anyone inter ested upon request. A combination vacuum distillation (wet process) and atmospheric rerun unit for lubricating oil, manufacturedfor a prominent midcontinent refinery. Alt ' of the equipment in Ibis installation including stills, towers, vaporcondensers,' steam jet ejectors, etc., was built by Ike Elliott Company. By L. M. FORNCROOK, Manager, a ll vacuum processes for the t\ distillation of petroleum -LA. products fall into one of two genera] classifications, commonly referred to as either wet or dry distillation. Wet Process The accompanying flow sheet and installation photograph illus trate one of the most successful wet distillation vacuum units now in operation in this country. Charging stock passes through two overhead condensers in series, then enters the pipe still, where it is heated and sent to the vaporizer section of the vacuum tower above HEAT TRANSFER DEPARTMENT Elliott Company, Jeannette, Penna. the point at which tower steam is admitted. In the reflux condenser, a sufficient portion of the vapors are condensed to supply the prop er amount of reflux to the tower to facilitate top temperature con trol. Uncondensed vaporsthen pass through a crude-cooled wax distil late condenser in which the wax distillate is recovered. The steam, together with light ends or gas oil, then passes into the final tubular condenser in which nearly all of the gas oil is condensed and re- covered. The steam is compressed by a booster ejector to a discharge pressure at which the steam is readily condensed at prevailing water temperatures. Non-conden sable gases are removed from the barometric condenser by a small two-stage air ejector. It is very important to keep the difference in pressure between the' suction of the booster ejector and' the vaporizer section of the tower at a minimum. It is further im portant to make sure that the wa- [21] CRIMDEBN00000380