Solids quench boiler and process

Claim 1

In a TRC process wherein hydrocarbon feed of hydrosulfurization residual oil, together with entrained inert solids and diluent gas, are passed through a cracking zone within a thermal cracking reactor for a residence time of 0.05 to 2 seconds to produce a stream of reactor effluent, wherein the temperature in said cracking zone is between 1300° F. and 2500° F., and after which said reactor effluent is quench cooled, the improvement comprising a process for sequentially quenching the reactor effluent including the steps of: a. introducing particulate solids into the effluent stream in the first quenching zone to partially quench the effluent; b. passing the composite stream of partially quenched effluent and particulate solids in indirect heat exchange relationship with a coolant in the second quenching zone to further cool the composite stream of effluent and particulate solids; c. separating the quenched and cooled gas from the particulate solids after the effluent and particulate solids have passed in indirect heat exchange relationship with the coolant; and d. returning the separated particulate solids for reintroduction to the effluent stream leaving the reactor.