Method of protecting heat exchange coils in a fluid catalytic cracking unit
AssigneePhillips Petroleum Company
InventorWilliam C. Rahlwes
Life of this patent
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Abstract
In a steam generator for recovering heat in a hot fluidized bed of solid particles, wherein coils of the steam generator make a 180.degree. U-bend, the U-bend portion of the coils are protected from overheating by installing an open top insulating box around the U-bend portion of the coil. In use solid particles from the circulating fluidized bed accumulate in the insulating box thus providing a non-moving layer of solid particles surrounding the U-bend which thermally insulates the U-bend portion of the coil from the higher temperature encountered in the moving fluidized bed.
Claims7
A method of protecting a U-bend portion of a horizontally oriented heat exchanger coil immersed in a hot fluidized bed of solid particles, which comprises the step of:
- forming a non-moving layer of solid particles around said U-bend portion of said heat exchanger coil immersed in said hot fluidized bed, wherein said non-moving layer is sufficient for insulating said U-bend portion from said hot fluidized bed;
- and
- wherein solid particles from said fluidized bed form said non-moving layer by accumulating in an apparatus attached to said U-bend portion, said apparatus comprising:
- (a) an insulating box for receiving said U-bend portion of said heat exchanger coil, said insulating box having an open top;
- and
- (b) means for attaching said insulating box to said heat exchanger coil for centrally containing said U-bend portion of said heat exchanger coil.
Dependencies are inferred from the claim text.