Secondary reaction quench device and method of use

A method to remove carbon deposits comprising

• (a) providing a reaction vessel having an inner wall, wherein said reaction vessel is configured to receive reactants and export products and byproducts;
• (b) reacting said reactants to form said products and byproducts, wherein said byproducts comprise carbon, at least a portion of which becomes deposited on the inner wall of said reaction vessel;
• (c) providing a primary quench device (PQD) configured to receive a fluid and disperse said fluid into said reaction vessel, wherein said PQD comprises an array of spray nozzles fixed on the inner wall of said reaction vessel at a first axial position with respect to the reaction vessel;
• (d) providing a secondary quench device (SQD) configured to receive a fluid and disperse said fluid into said reaction vessel, wherein said SQD comprises
• a pipe movable axially with respect to the reaction vessel, the pipe having a coolant entry end and a nozzle end, wherein said pipe is configured to be removably fixed inside said reaction vessel;
• and
• a spray nozzle that is fluidly connected to said pipe at its nozzle end via a fluid tight seal connection;
• (e) introducing a first coolant to the array of nozzles of said PQD at a first flow rate and dispersing said first coolant through said array of nozzles of said PQD to quench the reaction of said reactants in said reaction vessel;
• (f) introducing a second coolant to the pipe of said SQD at a second flow rate;
• and
• (g) dispersing the second coolant through the spray nozzle of said SQD onto the inner wall of said reaction vessel in an upstream direction with respect to the reaction to remove carbon deposits or to quench the reaction of said reactants or to accomplish both.