EXAMPLES 629 



Also (c) for the same pump when fitted with a suction pipe 36 feet long 

 and when running at sixty revolutions per minute against a head of 

 11-5 feet. 



Answer, (a) . . 1*15. 



(b) . . 1-01. 



(c) . . 1-10. 



(5) A double-acting pump, cylinder diameter 10 inches, stroke 

 18 inches, is fitted with an air vessel on the suction side 15 inches 

 diameter, and 4 feet 6 inches long measured from its point of junction 

 with the suction chamber. The length of suction pipe is 150 feet, its 

 diameter is 5 inches, the suction lift, measured to the level of the suction 

 chamber, is 10 feet, and air is admitted to the vessel until the mean 

 working level is 4 feet from the top, the fluctuation in level being 

 2 inches. Determine the acceleration in the suction column at the 

 beginning of the out-stroke ratio of connecting rod to crank length 

 being 4 : 1 when running at eighty revolutions per minute. 



h a = 23-5 feet. 



Answer , 



a, = -32 f.s.s. 



