Patent ID: 7610951

Claim:
A process to cool hot gas from a partial oxidation reactor that is fluidly connected at its lower end to a horizontal duct, which horizontal duct is fluidly connected to a tube having a main tubular part which is positioned in a vessel and is arranged vertically therein, and an upstream tubular part which is positioned in said horizontal duct and is arranged horizontally therein, said upstream tubular part being sealingly connected to a tube sheet that is also positioned in said horizontal duct and which is arranged vertically therein, said process comprising passing the hot gas through said tube, (i) cooling the exterior of said main tubular part by an evaporating liquid cooling medium flowing freely inside said vessel and around said tube, (ii) cooling the upstream tubular part and said tube sheet by passing a mixture of fresh liquid cooling medium and a defined part of the liquid cooling medium of activity (i) along the exterior of the upstream tubular part and a side of said tube sheet, and (iii) using as cooling medium in activity (i) the mixture of fresh liquid cooling medium and the defined part of the liquid cooling medium after being used to cool the upstream tubular part and tube sheet.