CHEMICAL COMPOSITION OF MAIZE GRAIN 637 



ducted " live 

 grain passes 

 grinders. The pro- 

 cess is diagrammati- 

 cally shown in Fig. 

 215. 



5 9 l ■ Grinding. 

 — The grain is now 

 in a fit state for 

 grinding. This 

 operation is per- 

 formed either by 

 stones or rollers, or 

 by a combination of 

 both. 



For grinding 

 maize and other 

 cereals or mill-pro- 

 ducts, which require 

 to be ground into a 

 fine meal.a millstone 

 has been put on the 

 market in recent 

 years, constructed 



' steam to toughen the bran-skin just before the 

 to the 



Maize 



\ Zigzag Separator 

 ' & Aspirator 



CHAP. 

 XIII. 



Magnetic 



ScourerSf 



Steaming 



% 



Stone Mill 



Kibbling Rolls 



Sifted 

 _JMaize 



Fig. 215.- 



High Grade 

 Meal MaizeMeal 



-Diagram of maize-meal plant. 



Bran 



of emery, or carborundum of a hard grain which, when dressed, 

 has a fine, sharp, cutting face. 



592. The Millstone Process. — The popular form of machine 

 consists of two stones placed vertically, one stationary and the 

 other or "runner stone" fixed to a disk-plate on a horizontal 

 shaft turning at the rate of 400 to 500 revolutions per minute, 

 according to the size of the stones. These stones are en- 

 closed in a suitable cast-iron case, with feed-hopper and inlet, 

 and two outlets to suit the position of the discharge spout. 

 The shaft has automatic self-oiling bearings with ball-bearing 

 thrust collar, and adjustable safety springs to prevent break- 

 age, allowing the stone to give, in case any hard substance 

 gets in. Better work is done if the maize is passed through 

 " kibblers " or a pair of " kibbling rolls," with the feed-regulat- 

 ing roll specially fluted for treating maize, before it is passed 



