Combustion gas control in Clayton generator

Specific construction od Clayton
Specyficzna konstrukcja generatora pary Claytona pozwala optymalnie wykorzystać powierzchnię grzewczą i energię spalin

The  Clayton  Steam  Generator  design  provides  a high  degree  of  heat  transfer  capability  because  of the spirally wound pancakes of boiler tubing.

Combustion  gases  are  passed  upward  from  the combustion  chamber  assisted  by  the  forced  draft blower. The tube itself serves as a baffle by virtue of the  turns  of  tubing  staggered  with  respect  to  the adjacent pancakes. Gas velocities are controlled by changing the tube spacing of adjacent pancakes.

As  the  hot  combustion  gases  release  their  heat  to the circulating feedwater the gas volume decreases. The spacing between the tubes is decreased as the gas volume declines, maintaining the constant high velocity  throughout  the  upward  path  of  the  flue gases, yielding maximized, controlled heat transfer.

Initial combustion gas temperatures are in the range of  1300  to  1650˚C.  At  the  flue  outlet  the  gas temperature  will  have  dropped  to  approximately 180˚C, and to about one-third of its original volume.

Because of the carefully calculated spacing between the  tubing  turns,  the  heat  transfer  rate  is  greatly increased.  This  design  allows  the  Clayton  Steam Generator to maintain a ratio of heating surface per boiler horsepower that is less than one half that of a conventional fire-tube boiler.

Flue gas economizing is accomplished with the tube spacing,  thus  eliminating  the  need  for  bulky, expensive stack economizers.