TRANSACTIONS OF SECTION G. gS3 



7. On the Reheating of Compressed Air. 

 By William George Walker, A.M.I.C.E., M.I.M.E. 



Considerable economy can be obtained by reheating compressed air before 

 admitting it to the engine. 



Reheating is accomplished by two methods : — 



1. By passing the air through hot pipes heated by a furnace fire. 



2. By passing the compressed air through water in a boiler at a temperature 

 depending on the pressure in the boiler. 



The author and Mr. P. Y. Alexander have investigated these methods 

 Generally speaking, the results show that an additional horse-power can be 

 obtained with an expenditure of one pound of coal, which is more efficient than 

 the most economical engine and boiler using steam. 



The experiments show that in many cases it would prove advantageous to use 

 compressed air in conjunction with steam in an ordinary engine. 



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