420 



ENGINEERING ON THE FARM 



After University of Minnesota 



Fig. 322. Round, center -connected boiler 

 with water arms 



sectional boiler may be 

 lengthened by the ad- 

 dition of sections and 

 the size of the fire box 

 be thereby increased (Fig. 

 320). In round hot- 

 water boilers two styles 

 are offered, one with a 

 flat-top fire box (Fig. 

 321), and one with water 

 arms, as shown in 

 Figures 322 and 323. 

 The one with the flat 

 top is much more easily 

 cleaned than the one 

 having water arms, and 

 the heating coil is more 

 easily installed. The 

 latter style is intended 

 to give more heating sur- 

 face in the fire box. 



Figures 321 and 322 

 show two methods of 

 connecting the water 

 plates or sections. Figure 



321 has a single opening between 

 sections at the back. Some have 

 smaller openings on each side. 

 Figure 322 shows a center- 

 connected heater. Figure 325 

 shows a good type of hot-air fire 

 box. It is made of boiler iron 

 and is riveted tight. This fire 

 chamber will last as long as the 

 rest of the furnace, but not so 

 long as the cast-iron sections. 



After University of Minnesota 



Fig. 323. Fire-box section of 



hot-water or steam boiler with 



water arms 



