| 摘要 |
430,989. Distilling wash oils. HOLMES & CO., Ltd., W. C., COOPER, C., and HENSHAW, D. M., Whitestone Iron Works, Huddersfield. Dec. 27, 1933, No. 36321. [Class 32] [See also Group XII] All the volatile hydrocarbons such as benzene, and a substantial proportion of carbon bisulphide are removed from combustible gases by scrubbing with a volume of wash oil unsaturated with respect to naphthalene of the order of 30 gallons per 1000 cubic feet and a proportion of the hydrocarbons are afterwards returned to the gases. The used wash oil may be only partly stripped and returned into contact with the gases while containing a substantial proportion of the absorbed substances, or some of the benzene recovered by a complete stripping is revaporized into the scrubbed gas. Wash oil passes from a washer 1 through a heat exchanger 3 in which it is cooled by indirect contact with stripped oil returned to a cooler 2. The warmed oil traverses a preheater 12 and the greater part then enters a still 7 through sprayer 21, some however passing to sprayer 20, which may alternatively be supplied through a byepass 38, and this quantity is controlled by a valve 41 in dependence on the temperature of the vapours passing to a condenser 24. Steam may be admitted to the still from a high pressure main 37 or from a source of exhaust steam, and the still maintained at 100‹ C., by condensation of the steam. Alternatively inert gases or a partial vacuum may be employed. Vapours are also drawn off from the still by a pipe 29 and condensed in a condenser 30. A small quantity of oil is withdrawn through a pipe 43 to a naphthalene recovering plant comprising a preheater 45, a still 47 in which it is completely stripped by live steam and vapour fractionating condensers 53, 54 in which naphthalene and like difficultly volatile bodies are recovered. Specifications 283,028, 293,702, 300,964, [all in Class 55 (ii)], 357,712, 366,646, [both in Group XII], and 393,041 are referred to.
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