Lower olefins - ethylene and propylene - occupy a leading position in the feedstock base of domestic and foreign petrochemistry. Thermal pyrolysis of hydrocarbons in tube furnaces, which ensures the almost maximum yield of target products, is the basic production process. This is due to continuous improvement of the basic equipment in the process units. In pyrolysis furnace block structures, it was directed toward making the process conditions more severe to attain the maximum yield of target products.