26 



BULLETIN 1067, IT. S. DEPARTMENT OF AGRICULTURE. 



TEST OF PUMPING PLANT NO. 3, AVOCA DRAINAGE DISTRICT, ST. MARY PARISH, LA. 



DESCRIPTION OP PLANT. 



This plant is of especial interest, inasmuch as it is the only steam 

 pumping plant in this section in which superheated steam is used. 

 The equipment consists of a cross-compound Lentz engine, a water- 

 tube boiler with 2,487 square feet of heating surface, a 72-inch centrif- 

 ugal drainage pump with two 48-inch suction pipes, a superheater 

 composed of 2-inch elements about 6 feet 2 inches long (amount of 

 surface unknown), a condenser, a duplex service pump which sup- 

 plies water to the open heater and to the water seal of the centrifugal 

 pump, and a duplex pump which takes the water from the heater and 

 forces it into the boiler. 



The engine cylinder dimensions are 18| and 31 inches with a 21- 

 inch stroke; the rods are each 4 inches in diameter. The valves are 



90 r— t— r— t— t— r— t— i— — i— i ° f ^ e P°PP et t JP e ' °P" 



erated by eccentrics 



and cams from a lay 

 shaft with axis parallel 

 to that of the cylinder. 

 The conditions for op- 

 erating the engine called 

 for a pressure of 175 

 pounds at the throttle, 

 200 degrees of super- 

 heat, and 26 inches of 

 vacuum. The super- 

 heater was not erected 

 in the direct path of 

 the hot gases, and there- 

 fore the superheat is 

 less than 200 degrees. 

 The condenser is of the 

 jet type. The boiler 

 walls are lagged with 

 cork, which is in turn covered with cement mortar. The suction and 

 discharge pipes of the pump are greatly increased in cross-section at 

 their outer ends. 



The test was begun in the morning and continued through the day, 

 but as there was no provision for lighting the plant except by oil 

 lanterns it was discontinued when night came on and resumed the 

 next day. 



The oil used during the test was Oklahoma crude oil with a specific 

 gravity of 0.885 at 92° F. The quantity used was weighed in a bucket 

 on a spring balance. The feed water was pumped through a hot- 

 water meter. At the close of the test an attempt was made to cali- 



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Fig. 2. — Efficiency of pumping plant No. 3,Avoca drainage dis- 

 trict, as indicated by test of Sept. 13 and 14, 1914. 



