A self cleaning pipe system, comprising a main pipe having a pipe wall which defines a pipe interior, and has a pipe circumference. The main pipe normally carries liquid or semi-liquid substances in a flow direction. A plurality of nozzle arrays are located along the main pipe. Each nozzle array comprises at least one, and preferably three or more nozzle assemblies. Each nozzle assembly includes a nozzle point which is directed through the pipe wall toward the pipe interior. A high pressure water supply is connected to the nozzle points to selectively create high pressure water jets in the flow direction, the jets all aimed at a convergence point. The nozzle arrays are selectively activated and deactivated to create a high pressure wave which clear the pipe of debris, and cleans the pipe.
A method is provided to inject steam into a hydrocarbon effluent passing through a transfer line exchanger (TLE) of a hydrocarbon cracking furnace to reduce the formation of a coke material on the TLE tubesheet. The apparatus that injects the steam is also provided to deliver a distributed steam flow in the low resonance area of the TLE cone.
