| 摘要 |
PURPOSE:To preheat hydrocarbons without decrease in utilization factor of flue gas heat content for miscellaneous hydrocarbon raw stocks by arranging an atomizer in a hydrocarbon passage together with an equipment for switching a supply point of steam. CONSTITUTION:A hydrocarbon feed stock such as naphtha, heavy condensate, etc., is mixed with steam at a confluent point 12, heated again in a convection section 1 and then introduced through a mixing nozzle 14 to an atomizer 20, wherein it is mixed with steam if necessary and atomized again. On the other hand, a steam source has its temperature controlled by adding water so as to make the (hydrocarbon raw stock)/(steam) ratio and the temperature optimum for a radiant section 2, taking into account varieties of hydrocarbon raw stocks, conditions of thermal cracking, etc. Valves 13 and 17 are used for selections of steam supply points, i.e., the steam is supplied to naphtha etc. by opening valve 13 and to heavy oil etc., by opening valve 17. The hydrocarbons are thus preheated before the thermal cracking takes place. |
