CAUSES OF COKE DEPOSITION IN FURNACE COILS OF DELAYED COKING UNITS AND VISBREAKING UNITS

The study of the coking process of reaction furnaces radiant coil tubes of delayed coking units (DCU), visbreaking was conducted. The objects of research were operating DCU of Russia and neighboring countries. In order to clarify the causes of furnace coil tubes accelerated coking, a comprehensive analysis of the delayed coking process technology was carried out at the unit. Laboratory studies of primary and secondary raw materials, coking products, the quality of the resulting coke, coke deposit composition were carried out, an analysis of the process flow diagram, hardware design of the process was carried out, the change dynamics in the furnace operating mode parameters between stops for «decoking» was studied. It was shown that the main reason for coil rapid coking at one of the surveyed units is the increased residence time of the product in the high-temperature zone of radiant coil chemical reactions. Based on the obtained research results, technical measures are proposed to reduce the radiant tube coking rate.