CHAPTER V. 

 THE DELIVERY MEMBERS 



WIND STACKERS 



The use of an air blast for stacking the straw has 

 become common. The air, straw and chaff are blown 

 from the interior of the machine by a suitable fan 

 through a pipe, the object being to direct the blast 

 so that a stack may be easily formed. 



When the pneumatic stacker was first introduced 

 the item of power was an important one. The first 

 fans used had large wings running at a high rate of 

 speed, and it is safe to say that it required as much 

 power to operate the stacker as it did to run the 

 rest of the separator. At first the fans were belted 

 to run from 1,000 to 1,700 revolutions per minute; 

 the enormous power required to do this either stalled 

 the engine or slipped the belt so that in fact the fans 

 were driven at much slower speed. 



In present practice the fan is driven at from 300 to 

 500 revolutions per minute and the blades of the fans 

 have been reduced, so that the power required is 

 greatly lessened. The work performed by the fan 

 of the wind stacker is setting the air and straw in 

 motion and forcing it through the straw pipe. The 

 more air set in motion and the greater speed given it, 

 the more power required. The weight of air passing 



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