TESTS OF DRAINAGE PUMPIXG PLAXIS. 



9 



The results given in Table 1 are very satisfactory, as they show an 

 efficiency of engine, transmission gears, and pump in every case 

 exceeding 38 per cent and in two cases considerably above that figure, 

 while the actual lift of the pump varied from 2.4 feet to 2.86 feet. 

 During the last observation the paddles dipped into the water to a 

 depth of approximately 1 foot, and the slip or backward flow was 

 quite large. The clearance on the side of paddles was about three- 

 fourths inch. 



Table 1. — Engine and pump test, South Side Planting Co.'s drainage wheel. 



Boiler 

 pressure. 



Indicated 

 horse- 

 power. 



Speed of Speed of 

 engine. wheel. 



• 1 

 ^r j discharge. 



Useful 

 water 

 horse- 

 power. 



Effi- 

 ciency. 



Lbs. per 

 sq. in. 

 40 

 40 

 3S 

 36 

 37 



13.43 

 12.61 

 10.37 

 8.80 

 6.95 



R. p. m. ; R. p. m. 

 61 2. 00 

 66 i 2. 17 

 68 2. 24 

 67.5 2.22 

 68 2. 24 



Feet. 



Sec.-ft. 



O. p. m. 





Per cent. 



2.4 

 2.8 

 2.7 

 2.86 



20.71 

 17.20 

 11.23 

 8.21 



9,299 

 7,723 

 5,042 

 3,686 



5. 59 

 5.41 

 3.41 

 2.66 



44.3 

 52.2 

 38.8 

 38.3 



i 38. 2 i 9. 68 



166.1 12. 22 j 12.69 



i 14. 34 



16,437 



14.27 



i 43. 4 



1 Mean. 



Duration of test, 1 hour. 



These results are confirmed by a test of a similar drainage wheel in 

 the old London Avenue pumping station in New Orleans, made in 

 August, 1900, by W. M. White. In this test between 50 and 60 

 cubic feet per second were pumped through a height varying from 4 

 to 5 feet. The efficiency of engine, gearing, and pump ranged from 

 45 to 50 per cent. The duty per 100 pounds of coal was approxi- 

 mately 13,000,000 foot-pounds. The water rate of the engine was 

 50.5 pounds per indicated horsepower-hour. The engine was of the 

 type used in Mississippi River steamboats; diameter of cylinder 18 

 inches; length of stroke 54 inches. During the test the engine made 

 about 35 revolutions per minute. 



I . vr OF CHAMBER-WHEEL PUMP ON WILLSWOOD PLANTATION, WAGGAMAN, LA. 



In a drainage pumping plant composed of large units such as arc 

 required ordinarily in drainage work, the pumps lift the water higher 

 than )- necessary, and while they arc efficient if credited with the 



higher lift, they lose their efficiency on low lifts when the actual 

 differeDCe Mi level is considered. 



This point is well illustrated by the test made at the drainage 

 pumping plant <>( Willswood plantation. At the time there were 

 three pumping units on tin- plantation, steam being furnished by t \\ 'o 

 water-tube boilers and one horizontal return tubular boiler. The 

 fuel was crude od and a feed-water beater was used. Following i 

 descripl ion of t he t hree units: 



!2 Bull I'".' 



