Steam generator arrangement

A steam flow path arrangement for covering the walls of the rear gas pass of a steam generator. The entire flow passes down the sidewalls with a minor portion then passing up through the rear wall to a superheater inlet header at an intermediate elevation. The major portion of the flow passes up the front wall and through hanger tubes to a roof header. From there the major portion passes across the roof and down the rear wall to the superheater inlet header at the intermediate elevation.

What is claimed is:

1. A steam flow path arrangement for a vertical gas flow pass of a steam generator; said vertical gas flow pass having a rectangular cross section and an opening in a front wall at an upper elevation for the ingress of flue gas, an opening at the bottom for egress of flue gas, and a tubular superheater located within said gas pass, comprising: a first plurality of parallel tubes lining the roof of said gas pass; a second plurality of parallel tubes lining the rear wall of said gas pass from the roof elevation to an intermediate elevation; a third plurality of parallel tubes lining the side walls of said gas pass from the roof elevation to a lower elevation; a fourth plurality of parallel tubes lining the front wall of said gas pass from the top of said front wall to said lower elevation, said tubes also passing through the front wall opening; a fifth plurality of parallel tubes lining the rear wall of said gas pass from said intermediate elevation to said lower elevation; first header means attached to the upper end of said third plurality of tubes for conveying substantially all of the steam flow therethrough; a second header means connected to the bottom end of said third plurality of parallel tubes for receiving substantially all the steam flow; a third header means connected to the bottom of said fifth plurality of tubes; a first conveying means for conveying a minor portion of the steam flow from said second header means to said third header means; fourth header means connected to the bottom of said fourth plurality of parallel tubes; a second conveying means for conveying a major portion of the steam flow from said second header means to said fourth header means; a fifth header means connected to the bottom of said second plurality of parallel tubes and to the top of said fifth plurality of parallel tubes; said fourth, first, and second plurality of parallel tubes connected for serial flow therethrough; and supply tubes connecting said fifth header to said tubular superheater.

2. A steam flow path arrangement as in claim 1 wherein said second headers of each sidewall and said fourth header of the front wall are joined by 90.degree. elbows to form a U-shaped header.

3. The steam flow path arrangement as in claim 2 wherein said third header of the rear wall is joined by 90.degree. elbows to said second headers of the sidewall, thereby forming a ring header of said second, third, and fourth headers.

4. A steam flow path arrangement as in claim 3 including also partition plates and each of said second headers for dividing the steam flow through said third plurality of parallel tubes into a minor portion for transmittal to said third header and a major portion for transmittal to said fourth header.

5. An apparatus as in any one of claims 1 through 4 having also a sixth header connected to the top of said fourth plurality of parallel tubes and to the inlet end of said first plurality of parallel tubes.

6. An apparatus as in claim 1 or 4 wherein said fifth header is comprised of a plurality of stub headers.

7. An apparatus as in claim 1 or 4 wherein said first header is comprised of a plurality of stub headers.