Water and gas are thus removed from the emulsion in the preheating zones prior to direct heating of the emulsion in the direct heating zone to reduce heat loss and fouling of the emulsion heating means in the direct heating zone, and {HEAD ~ additional separation} of the emulsion phases occurs in {TAIL ~ the post heating zone} prior to final phase separation in the settling zone to improve the settling action 
Water and gas are thus removed from the emulsion in the preheating zones prior to direct heating of the emulsion in the direct heating zone to reduce heat loss and fouling of the emulsion heating means in the direct heating zone , and { HEAD ~ additional separation } of the emulsion phases occurs in { TAIL ~ the post heating zone } prior to final phase separation in the settling zone to improve the settling action
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