Waste heat boiler and steam superheater system

In a system comprising a waste heat boiler, a steam drum, a steam superheater, means for passing water through said waste heat boiler to produce steam, means for passing the steam to said steam drum, means for passing steam from said steam drum through said steam superheater to produce superheated steam and means for passing a process stream through the shell of said waste heat boiler, the improvement which comprises:

• a waste heat boiler comprising
• a shell having at the lower end a portion of reduced cross-section containing an expansion joint,
• a tube bundle within said shell, the top of said bundle affixed to said shell and the bottom being a hollow floating head,
• a head at the upper end of said shell having a plurality of steam outlets,
• pipe means attached to said floating head, said pipe means extending through said lower end portion of reduced cross-section of said shell and attached to said shell below said expansion joint for introducing water to said tubes of said tube bundle,
• inlet means in said shell for passing a process stream in indirect cocurrent exchange with the water in said tubes, and
• outlet means in said shell for removal of said process stream.