A process for producing olefins, the process comprising: during a cracking cycle, passing a hydrocarbon feed and optionally steam through a heat exchange tube in a radiant heating chamber of a heater at conditions to crack at least a portion of the hydrocarbon to form an effluent comprising olefins and byproducts including heavier hydrocarbons and coke; during a decoking cycle, passing at least one of nitrogen, steam, air, and oxygen through the heat exchange tube in the radiant heating chamber of the heater at conditions to decoke at least a portion of the heat exchange tube to form a decoke effluent; cooling the effluent or the decoke effluent in a primary transfer line exchanger to form a cooled effluent comprising a gaseous fraction and a foulant fraction; transferring the cooled effluent through a flow conduit to a secondary transfer line exchanger, wherein the flow conduit branches, causing (i) the flow of the gaseous fraction to change direction before entering the secondary transfer line exchanger, during at least the cracking cycle, and (ii) the flow of the foulant fraction to continue into a coke catcher; accumulating an amount of the foulant fraction in the coke catcher or a first portion thereof; and emptying accumulated foulant fraction from the coke catcher or a second portion thereof without shutting down the heater, wherein the accumulating step comprises accumulating an amount of the foulant fraction in a first portion of the coke catcher, the process further comprising: transporting the accumulated foulant to a second portion of the foulant collection device; isolating the first portion of the coke catcher from the second portion of the coke catcher prior to the emptying step, wherein the transporting the accumulated foulant from the first portion to the second portion is initiated when transitioning from the coking cycle to the decoking cycle, and wherein, during the decoking cycle, the decoke effluent passes through at least the first portion of the coke catcher. during a cracking cycle, passing a hydrocarbon feed and optionally steam through a heat exchange tube in a radiant heating chamber of a heater at conditions to crack at least a portion of the hydrocarbon to form an effluent comprising olefins and byproducts including heavier hydrocarbons and coke; during a decoking cycle, passing at least one of nitrogen, steam, air, and oxygen through the heat exchange tube in the radiant heating chamber of the heater at conditions to decoke at least a portion of the heat exchange tube to form a decoke effluent; cooling the effluent or the decoke effluent in a primary transfer line exchanger to form a cooled effluent comprising a gaseous fraction and a foulant fraction; transferring the cooled effluent through a flow conduit to a secondary transfer line exchanger, wherein the flow conduit branches, causing (i) the flow of the gaseous fraction to change direction before entering the secondary transfer line exchanger, during at least the cracking cycle, and (ii) the flow of the foulant fraction to continue into a coke catcher; accumulating an amount of the foulant fraction in the coke catcher or a first portion thereof; and emptying accumulated foulant fraction from the coke catcher or a second portion thereof without shutting down the heater, wherein the accumulating step comprises accumulating an amount of the foulant fraction in a first portion of the coke catcher, the process further comprising: transporting the accumulated foulant to a second portion of the foulant collection device; isolating the first portion of the coke catcher from the second portion of the coke catcher prior to the emptying step, transporting the accumulated foulant to a second portion of the foulant collection device; isolating the first portion of the coke catcher from the second portion of the coke catcher prior to the emptying step, wherein the transporting the accumulated foulant from the first portion to the second portion is initiated when transitioning from the coking cycle to the decoking cycle, and wherein, during the decoking cycle, the decoke effluent passes through at least the first portion of the coke catcher.