A process for cracking liquid hydrocarbon feed to produce cracked gaseous hydrocarbons, the process comprising the steps of: (a) feeding a liquid hydrocarbon feed stream to an olefins furnace; (b) cracking the liquid hydrocarbon feed stream in the olefins furnace to produce a hot gaseous cracked effluent stream having a temperature of 760 °C (1400 °F) to 899 °C (1650° F); (c) feeding the hot gaseous cracked effluent stream from the olefins furnace to the first section of a primary transfer line heat exchanger, which first section of said primary TLE comprises a shell-and-tube heat exchanger where the hot gaseous cracked effluent stream is indirectly cooled on the tube side while generating high-pressure steam from saturated steam on the shell side; (d) feeding the gaseous cracked effluent exiting the first section of the primary TLE to the tube side of a second section of the primary TLE, where a flow obstruction means is positioned in said tube side of the second section to create a low-pressure zone in said gaseous cracked effluent stream immediately downstream of said flow obstruction means, and where the gaseous cracked effluent stream is indirectly cooled on the tube side while generating saturated steam from boiler feed water on the shell side; (e) injecting a wetting fluid tangentially into said gaseous cracked effluent stream at said low-pressure zone at a momentum sufficient to cause said wetting fluid to flow circumferentially around the inside surface of said tube side; providing a sharp interface between said gaseous cracked effluent stream and said first wetting fluid; and causing said first wetting fluid to contact and wet the downstream face of said flow obstruction means; (f) wherein the weight ratio of wetting fluid to the hot gaseous feed stream entering the tube side of a second section of the primary TLE is 0.5 to 2.0, the exit temperature of the gaseous effluent stream from the first section of said primary TLE is 593 °C (1100 ° F) to 649 ° C (1200° F) and the exit temperature of the gaseous effluent stream from the second section of the primary TLE is approximately 10 °C (50° F) above the temperature of the steam being generated; (g) feeding the gaseous cracked effluent stream exiting from the second section of said primary TLE to a separator; and (h) separating in the separator, a separator bottoms stream comprising tar and heavier hydrocarbons and a separator product stream comprising an olefin product. (a) feeding a liquid hydrocarbon feed stream to an olefins furnace; (b) cracking the liquid hydrocarbon feed stream in the olefins furnace to produce a hot gaseous cracked effluent stream having a temperature of 760 °C (1400 °F) to 899 °C (1650° F); (c) feeding the hot gaseous cracked effluent stream from the olefins furnace to the first section of a primary transfer line heat exchanger, which first section of said primary TLE comprises a shell-and-tube heat exchanger where the hot gaseous cracked effluent stream is indirectly cooled on the tube side while generating high-pressure steam from saturated steam on the shell side; (d) feeding the gaseous cracked effluent exiting the first section of the primary TLE to the tube side of a second section of the primary TLE, where a flow obstruction means is positioned in said tube side of the second section to create a low-pressure zone in said gaseous cracked effluent stream immediately downstream of said flow obstruction means, and where the gaseous cracked effluent stream is indirectly cooled on the tube side while generating saturated steam from boiler feed water on the shell side; (e) injecting a wetting fluid tangentially into said gaseous cracked effluent stream at said low-pressure zone at a momentum sufficient to cause said wetting fluid to flow circumferentially around the inside surface of said tube side; providing a sharp interface between said gaseous cracked effluent stream and said first wetting fluid; and causing said first wetting fluid to contact and wet the downstream face of said flow obstruction means; (f) wherein the weight ratio of wetting fluid to the hot gaseous feed stream entering the tube side of a second section of the primary TLE is 0.5 to 2.0, the exit temperature of the gaseous effluent stream from the first section of said primary TLE is 593 °C (1100 ° F) to 649 ° C (1200° F) and the exit temperature of the gaseous effluent stream from the second section of the primary TLE is approximately 10 °C (50° F) above the temperature of the steam being generated; (g) feeding the gaseous cracked effluent stream exiting from the second section of said primary TLE to a separator; and (h) separating in the separator, a separator bottoms stream comprising tar and heavier hydrocarbons and a separator product stream comprising an olefin product.