Journal . nsure that the fogwhich is to be extracted is present in the gas beforeit reaches the scrubber. The extraction tempera-ture in this section would be from 70 to 80° to carbonising conditions. From thispoint the gas is treated in normal direct recoverymanner. For instance it is first freed fromammonia in the direct recovery saturator, L, andthen naphthalene removed in, say, an Ottowater spray naphthalene extractor, M. The gasis then forced by the exhausters through the usualcreosote scrubbers for the recovery of light the gas was required for town lighting, however,
Journal . nsure that the fogwhich is to be extracted is present in the gas beforeit reaches the scrubber. The extraction tempera-ture in this section would be from 70 to 80° to carbonising conditions. From thispoint the gas is treated in normal direct recoverymanner. For instance it is first freed fromammonia in the direct recovery saturator, L, andthen naphthalene removed in, say, an Ottowater spray naphthalene extractor, M. The gasis then forced by the exhausters through the usualcreosote scrubbers for the recovery of light the gas was required for town lighting, however,purifiers would take the place of the creosotescrubbers. In this particular case it is to be remembered that the gas would be saturated withnaphthalene vapour and any fall of temperaturewould cause a (leposition. Tlie content of naph-thalene lould he reduced by anthracene oil in theIollowin.: on the lines of tbe Youngand .Vitken process and using the plant indicateddiagrammatically in Pig. Anthracene Oil Fio. Washer. The cooled gas or a proportion of the total bulkafter being heated to 80° C. passes into the bottomchamber of a washer similar in principle to theYoung and Aitken analyser. Exhaust steam, orthe sensible heat of the recovered tar fractions,or both could be used for this heating. This is not;indicated in the diagram, but a heat exchanger Lsshown in which the washing oil is cooled from itsrecovery temperature to the temperature of thegas, the gas being itself partly heated. Thecooled anthracene oil fills each of the trays up tothe level of the overflow and runs through thewasher in a continuous stream. In the bottom ofthe washer by means of a steam coil the oil ismaintained at 80° C, at which temperature itleaves the washer. At 80° C. the anthracene oilcannot dissolve benzene and in fact, so far asexamination of direct recovery tar extracted atthis temperature indicates, very little solventnaphtha even is removed from the gas. This i
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
