114 



THE IRRIGATION AGE. 



HIGH EFFICIENCY PUMPING PLANTS 



Although the question of efficiency does not re- 

 ceive much consideration when installing inde- 

 pendent pumping plants for small farms, it is a very 

 important feature when selecting pumping ma- 

 chinery for a large central plant. This is especially 

 true when the pumps are required to operate against 

 high heads. In such cases the excess cost of power 

 resulting from a difference of 5 or 10 per cent in 

 the efficiency of the pumping machinery is a de- 

 ciding factor in the ultimate success of the irriga- 

 tion system. 



There are a number of points to bear in mind 

 when designing a pumping plant for irrigation serv- 

 ice. The most important are the following: 



1. The location of the plant should be as close 

 as possible to source of supply. 



2. The number and size of units should be 

 selected to give the best results throughout the en- 

 tire range of pumping conditions. 



3. The arrangement and size of pipe lines 

 should be such that loss of head (which means in- 

 creased power) is avoided as much as possible. 



4. Last, but not least, the different sources of 



WORTHINGTON PUMP. 



power should be very carefully studied before se- 

 lecting the type of prime mover for driving the 

 pumps. 



The location of the pumping plant and the 

 type of pumping machinery depend, of course, upon 

 the nature of the source of supply. If the supply is 

 taken from a river or lake of nearly constant water 

 level, the horizontal shaft pump is the most suitable 

 selection. If possible, the pumping plant should be 

 located over the water with a suction lift not ex- 

 ceeding ten (10) feet. This arrangement eliminates 

 bends in the suction line and results in increased 

 efficiency. 



If the level of water at the source of supply 

 varies to such an extent that the suction lift at low 

 water is excessive, the vertical shaft pump will 

 g.ive the best results. The pump should be placed 

 ih a watertight pit within easy suction lift at low 

 tyater, and the prime mover located above the high 

 water level. 



The variation in both capacity and pumping 

 head should be carefully determined before select- 

 ing the number and size of pumping units. For a 

 wide fluctuation in capacity, the units should be of 

 such size that the maximum efficiency can, be ob- 

 tained at all conditions. It is sometimes advisable 

 to install large units to take care of the maximum 

 flow and pumps of smaller size to operate during the 



periods of lesser consumption. In other words, the 

 smaller unit operating at maximum load will give 

 a better over-all efficiency than the large unit pump- 

 ing at greatly reduced capacity. 



If the lay of the land is such that there is a 

 wide variation in levels, much better results can 

 be obtained by dividing the system into groups ; 

 and designing the pumps to best meet the condi- 

 tions of each section, rather than attempt to irri- 

 gate the whole tract by pumping all the water to the 

 highest level. 



It must be remembered that the ultimate effi- 

 ciency of a pumping plant depends not alone on the 

 selection of high grade machinery. The friction 

 loss through pipe lines is a very considerable fac- 

 tor, and in many plants considerable power is con- 

 sumed to overcome friction which might better have 

 been expended in pumping water. While the first 

 cost of a large pipe line may appear excessive, the 

 difference in the cost of operation should be care- 

 fully calculated before a final selection is made. The 

 connections from the pumps to the suction and dis- 

 charge mains should be as direct as possible and all 

 useless valves and fittings eliminated. It is much 

 cheaper in many cases to purchase a pump with 

 special suction and discharge nozzles rather than 

 attempt to meet the condition with a standard 

 stock pump. 



The great development of electrical energy 

 from the vast natural sources of power has resulted 

 in the extensive use of motor driven machinery not 

 only for pumping water, but many other purposes 

 around the farm. This condition naturally leads 

 to the selection of the electric motor as the most 

 popular prime mover for driving irrigation pumps. 

 It must not be forgotten, however, that the com- 

 bustion engine has now been developed to a very 

 high degree of efficiency and reliability, and this 

 type of prime mover makes a very satisfactory in- 

 stallation, and in many cases will show a saving 

 in the cost of fuel over electrically driven pumps. 

 Except for very large units such as are used for 

 irrigation on the rice and sugar plantations of 

 Louisiana and Texas, the steam engine with its 

 necessary boiler plant and stand by losses is a 

 rather expensive source of power. 



The illustrations accompanying this article 

 represent types of high efficiency centrifugal pumps, 

 manufactured by Henry R. Worthington, 115 

 Broadway, New York. This concern has made a 

 careful study of the irrigation problem and is pre- 

 pared to make estimates and furnish complete data 

 on the subject. 



$20,000,000 FOR MIDDLE WEST 



An appropriation of $20,000,000 for the con- 

 struction of reservoirs and lakes to impound flood 

 waters in western Kansas, Oklahoma, Nebraska, 

 eastern Colorado and New Mexico is asked in a bill 

 which Senator Bristow has introduced in the sen- 

 ate. An additional appropriation of $1,000,000 for 

 investigation of the feasibility of such projects is 

 also asked. This latter appropriation, if granted, 

 will permit the continuance of similar work begun 

 in western Kansas and Oklahoma under an appro- 

 priation granted in 1912. 



