Process heater

• Main Authors: O'SULLIVAN, THOMAS F, POLLOCK, WILLIAM H
• Format: Patent
• Language: English
• Published: 25.12.1979
• Subjects: AIR; BLASTING; CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FORCOMBUSTION CHAMBERS, e.g. FIREBRIDGES; CHEMISTRY; COMBUSTION APPARATUS; COMBUSTION PROCESSES; CRACKING HYDROCARBON OILS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDEDFOR; DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OFGENERAL APPLICATION; DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS,IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KINDOF FURNACE; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS INCOMBUSTION CHAMBERS; FLUES; FUELS; FURNACES; HEAT EXCHANGE IN GENERAL; HEATING; KILNS; LIGHTING; LUBRICANTS; MECHANICAL ENGINEERING; METALLURGY; METHODS OF STEAM GENERATION; METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL; METHODSOR APPARATUS FOR COMBUSTION USING FLUID FUELOR SOLID FUEL SUSPENDED IN; MINERAL WAXES; OVENS; PEAT; PETROLEUM, GAS OR COKE INDUSTRIES; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVEHYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, ORGASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTIONRESIDUES; RETORTS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTIONAPPARATUS; STEAM BOILERS; STEAM GENERATION; TECHNICAL GASES CONTAINING CARBON MONOXIDE; WEAPONS

A process heater which is fired by an ash containing fuel, generally coal, has a housing which includes a front radiant section and a rear convection section. The radiant section is provided with vertically extending process tubes against the walls thereof, arranged in a single row, and horizontal process tubes arranged in a single row across the roof. The horizontal and vertical tubes contain longitudinal fins over the length thereof, with adjacent fins being in contact with each other to provide a fin tube wall which prevents a build-up of ash behind the tubes. The bottom of the radiant section is downwardly and inwardly sloped and terminates in an ash collecting hopper. The process tubes extend along the downwardly and inwardly sloped portion to provide cooling which prevents ash melting whereby ash enters the hopper in solid form for removal. The vertical and horizontal process tubes are interconnected to provide for at least two passes of process fluid through the radiant section.