PRINCIPLES OF NAVAL ENGINEERING 



CIRCULATING 

 PUMP 



LEGEND 



1. ECONOMIZER INLET HEADER 



1. ECONOMIZER OUTLET HEADER 



3. SIDE WALL AND FLOOR CIRCUIT INLET HEADER 



4- SIDE WALL AND FLOOR CIRCUIT OUTLET HEADER 



5. PRIMARY EVAPORATOR AND REAR WALL CIRCUIT INLET HEADER 



6. PRIMARY EVAPORATOR AND REAR WALL CIRCUIT OUTLET HEADER 



7. LOWER SECONDARY EVAPORATOR CIRCUIT INLET HEADER 



8. UPPER SECONDARY EVAPORATOR CIRCUIT INLET HEADER 



9. SECONDARY EVAPORATOR OUTLET HEADER 



10. SUPERHEATER INLET HEADER 



11. SUPERHEATER OUTLET HEADEft 



147.85 



Figure 10-24.— Schematic diagram of controlled circulation boiler. 



of the pressurized furnace, firing downward into 

 the furnace. 



The burners, specially designed for the 

 pressurized-furnace boiler, are quite unlike any 

 we have thus far considered. The burners are 

 designed to burn distillate fuel rather than Navy 

 Special fuel oil. There are no air register doors. 

 There are three burners per boiler, and each 

 burner includes a special type of straight me- 

 chanical atomizer (not return-flow) which uti- 

 lizes three sprayer plates at the same time. All 

 three burners are operated simultaneously, and 

 all three sprayer plates remain in place in each 

 atomizer. The sprayer plates operate in se- 

 quence to meet changing conditions of load. The 

 design of these burners allows an enormously 

 wide range of operation without cutting burners 



in or out and without even changing sprayer 

 plates. 



The generating tubes run vertically inside 

 the pressurized furnace. The superheater is an 

 annular pancake arrangement inserted into the 

 bottom of the pressure vessel. The superheater 

 is designed to be removed without disturbing the 

 main components of the boiler. 



The air compressor which supplies the com- 

 bustion air under pressure is driven by a gas 

 turbine. The air compressor and the gas turbine 

 together are referred to as the supercharger . 

 Part of the energy needed for driving the gas 

 turbine is obtained from the combustion gases 

 leaving the boiler furnace. The combustion gases 

 expand through the gas turbine, and some of the 

 heat is converted into work. This is the same 



258 



