3190 



Chapter 26 



AIR LOCK 



GREEN FUEL IN 



COMBUSTION AIR IN 



FUEL HOPPER 



FUEL FEED SCREW 



COMBUSTION AIR 

 PREHEATER 



HOT GAS 



COMBUSTION 

 ZONE 



DRY FUEL TO 

 COMBUSTION ZONE 



AUXILIARY BURNER 



TUYERES 



REFRACTORY 



Figure 26-21. — Cross sectional view of the prototype of the Jasper-Koch burner. 



STEAM AND ELECTRICAL GENERATION 



Steam delivery from boilers can be expressed as kilo Btu's per hour, boiler 

 horsepower, or pounds per hour (Miller 1976). Kilo Btu means 1 ,000 Btu and is 

 a term commonly used by engineers. 



Operators of small steam generating units sometimes express steam delivery 

 in boiler horsepower (BoHP) a unit that bears no relationshiop to engine 

 horsepower. Boiler horsepower was more commonly used in past decades when 

 small steam plants were used to drive machinery. Boiler horsepower is the 

 energy required for the evaporation of 34.5 lb of water per hour to saturated 

 steam at 212°F at atmospheric pressure. The equivalent amount of heat energy in 

 Btu's is 33,480 Btu/hr. 



The amount of wood required to generate 1 BoHP can be calculated if boiler 

 efficiency and fuel moisture content are known. The average green pine-site 

 hardwood with 42 percent moisture content has an available heat of 4,540 Btu/lb 



