THE IERIGAT10N AGE. 



151 



SUN POWER PLANT IN EGYPT. 

 - By Frank C. Perkins. 



The new sun power pumping installation in 

 Egypt as designed by Mr. Frank Shuman, an 

 American engineer, may be noted in the accom- 

 panying illustration. The reflectors and gener- 

 ators of sun power plant in Egypt differ from the 

 Philadelphia steam generators, in which plane mir- 

 rors are used. In the Egyptian plant the reflectors 

 are parabolical and the power is said to be much 

 greater, or one hundred as against about thirty. 



The Egyptian plant is located at Meadi, a 

 suburb of Cairo, on the road to Helouan, and the 

 steam generator part of the installation covers a 

 great deal of ground, as there are five reflectors, 

 each 204 feet long, the cross section being in the 

 form of a parabola with the generator units at the 

 focus. 



They are made of zinc, of rectangular section, 

 14 inches wide, with sides only fy% inch apart, and 

 is painted with a special black paint of high heat 

 absorbing qualities. The glass plates and the in- 

 sulators used in the original plan have been dis- 

 carded and at the upper edge the generator is en- 

 larged into a steam collector 4 inches in diameter, 

 and it has a fall of 6 inches in its length of 204 

 feet, the collector being connected to the main steam 

 pipe at the upper end and the feed water introduced 

 at the lower end. 



The sides of the reflector are lined with silvered 

 glass mirrors ranging in size from about a square 

 foot at the mouth to a quarter that size near the 

 vertex. The reflector and boiler are carried on high 

 braced steel cradles, the outer circumference of 

 which is in the form of a segment of a circle and has 

 a rack attached, gearing with a pinion which serves 

 to rotate the reflector so that it may always face 

 the sun. The main engine furnishes the power for 

 this operation through a pair of friction pulleys, 

 which are put in gear by a special regulator, of 

 which a thermostat is an important part. 



The reflectors follow the sun automatically 

 through the day. There are only five banks of 

 heaters in this entire plant, instead of the twenty- 

 six used in America, and they have been put widely 

 apart so that no one shall shade another, an extra 

 hour of sunshine at each end of the day being thus 

 saved. 



Dust is a troublesome matter in Egypt, and 

 with it in view, provision has been made for tilting 

 the whole generators to one side and washing them 

 off with a hose. It has been found best to work 

 with a pressure slightly below that of the atmos- 

 phere and corresponding to a temperature about 

 200 degrees Fahr. In order to use this low pressure 

 steam efficiently the inventor has designed an en- 

 gine which has given exceedingly good results 

 under test. 



A surface condenser is used, the vacuum being 

 obtained before starting the plant by running the 

 air pump with a small petrol motor, which is 

 stopped as soon as the vacuum is obtained and the 

 main engine is operating. In reference to the gen- 

 eration of mechanical power by the absorption of 

 the sun's rays, Mr. Frank Shuman points out the 

 fact that the direct utilization of the natural forces 

 in the development of power suitable for human 



activities has been for centuries a matter of con- 

 tinued scientific research. While to a limited ex- 

 tent these forces have been used from the dawn 

 of civilization in the common forms of the windmill 

 and various types of water driven motors. 



It has not been hitherto possible to practically 

 utilize the central dominating forces of nature the 

 sun heat in any direct manner, though obviously 

 all power generators are dependent upon this great 

 source for their existence. Although for many years 

 engineers and physicists have been occupied with 

 this problem, notably Johni Ericson, Ferry, Millo- 

 chan, Mouchat and Tellier, in France ; Guntner and 

 Althaus, in Germany, and Langley and Willsie, in 

 America. 



They based their efforts either upon the use 

 of lenses or mirror to concentrate the sun's rays 

 upon a small surface, or upon the heating of fluids 

 of a low-boiling point, with subsequent power gen- 

 eration from the vapor under pressure. It has 

 always been attempted to create vapor at high 

 pressure, and then utilize this in the ordinary 

 engine, with the high temperatures involved, the 

 losses by conduction and conviction are so great 



Sun Plant in Operation in Egypt. 



that the power produced was of no commercial 

 value. 



Where lenses or mirrors are used, the primary 

 cost of the lenses and the apparatus necessary to 

 continuously present them toward the sun, have 

 rendered them impracticable. Where fluids of low- 

 boiling point, such as ether, sulphurous acid, and 

 liquid ammonia, were used, the results were of little 

 value by reason of the inherent inefficiency of these 

 fluids as power generators. Mr. Shuman holds that 

 a sun-power plant, in order to be practicable, must 

 possess, first, high efficiency, low cost of installa- 

 tion and maintenance, well marked length of serv- 

 ice, and should not require specially trained me- 

 chanics for its operation. In order to be efficient, 

 it is not necessary that the plant generate continu- 

 ously, inasmuch as the great value of such a plant 

 lies in its use as an irrigation apparatus ; it is only 

 necessary that the plant run about eight hours 

 daily. 



It must, however, consist of units which may 

 be assembled to produce a power plant of any re- 

 quired size, the larger the plant the greater the 

 efficiency. It is entirely practicable to produce a 

 sun power plant in this manner up to 10,000 horse- 



