1042 



TURBINE 



mechanical impurities in the water ; and lastly, the lubrication of the foot spindle of 

 the vertical wheel, revolving at very great velocity, is attended with considerable dif- 

 ficulty and inconvenience, especially where the engine-room is at a considerable distance 

 below the surface of the earth, and it is requisite, as in the case of pumping wheels, 

 to keep the machinery in action continuously for long periods of time. The 

 form of wheel of which a notice is here appended, was introduced into the Saxon 

 mines about the year 1849 by Herr Schwamkrug, inspector of machinery at the 

 Royal Mines and Smelting Works at Freiberg, and since that time several have been 

 introduced for pumping, winding, driving stamp-heads, &c. The example selected for 

 illustration was built to take the place of two overshot water-wheels, employed in 

 pumping water at the mine ' Churprinz Friedrich August ' : it differs from the usual 

 form of turbine in having the wheel placed vertically, and in having the water sup- 

 plied through a small number of guide-curves near the lowest part. In this latter 

 respect it resembles the tangential turbine of General Poncelet, with this difference that 

 the water flows from the inner to the outer circumference, instead of the reverse way, as 

 is the case in Poncelet's wheel, The construction of the wheel is as follows : a, fig. 

 2062, is the tubular axle of cast iron which carries the seating for the arms, s, which is 

 similar to that usually used for large water-wheels ; to the ends of the arms is attached 

 the wheel w, which is formed of two brags or shroudings of sheet iron, each 13 inches 

 deep, measured radially, and of a total height of 10 feet 2 inches ; these two rings are 

 maintained at a distance of 6 inches apart, by means of 44 sheet-iron buckets of the 

 form shown in the smaller detailed figure, Jig. 2063 ; the driving water is admitted 



through the pressure pipe, p, in which is placed the 

 admission throttle, t, and turned through a pipe of 

 rectangular section (shown in the smaller figure) 

 into the sluice box, s, which contains the two guide- 

 curves, v, 1/, which are moveable about the centres, 

 c, c'. by means of the levers, /, I'; by means of these 

 guide-curves when fully opened, as shown in the 

 figure, the water is admitted into the buckets in two 

 parallel streams or jets of 5^ inches in breadth, and 

 l^ths in. in thickness ; the power is transmitted from 

 the axle of the wheel by a pinion with 28 teeth, 

 which draws the large toothed wheel, x, which acts 

 on a third shaft carrying the pump-cranks. The 

 wheel is constructed to work under a head of 147 feet, 

 and makes about 130 revolutions per minute, with a maximum quantity of 550 cubic 

 feet of water, equal to nearly 175 horse-power. A series of dynamometrical experi- 

 ments on a wheel of similar construction of 7 feet 9 inches in diameter, with a discharge 

 varying from 39 to 134 cubic feet, with a head of 103 feet, gave an available duty of 

 from 58 to 70 per cent., the number of revolutions varying from 112 to 148 per minute. 

 In conclusion, it may be remarked that the vertical turbine may b employed with 

 advantage where the available fall of water is too great to be employed on a single 

 overshot water-wheel ; and although a less perfect machine than the water-pressure 

 engine, it is of simpler construction, and may be preferred where, from the hardness 

 or yielding nature of the rock, it becomes difficult to construct large machine-rooms 

 or wheel-pits underground. In practice it is found necessary to surround the wheel 

 with a casing of wood, in order to prevent the affluent water from being projected to a 

 distance- by centrifugal action. 



A fine model of one of these turbines, with two sets of buckets, constructed for the 

 purpose of winding (Turbinengopel), may be seen at the Museum of Practical Geology, 

 Jennyn Street. 



For further information on this subject, we may refer to the PolytechniscJies Central- 

 blatt, Nos. 8, 9, for 1845, and No. 3 for 1850 ; to the Jahrbuch fur den Berg- mid 

 Hiittenmann, for 1850 and 1853. The subject of turbines is treated in great detail in 

 Weisbach's 'Mechanics of Machinery and Engineering.' Redlenbache's Theorie und 

 Bau der Turkmen und Ventilatoren, Mannheim, 1844, is the best and most complete 

 work on the subject. Notices of Fourneyron's, Jouval's, and Fontaine's turbines are to 

 be found in Glyn's ' Rudimentary Treatise on Water-Power,' in Weale's Series. The 

 original notice of Fourneyron's turbine is published in the Bulletin de la Societe 

 d 1 Encouragement, for 1834, and several new forms are noticed in the various volumes 

 of Armengaud's Publication Industritlle. 



The name of Vortex Wheel has been given to a modification of the turbine by Mr. 

 James Thomson of Belfast. In this machine the moving wheel is placed within a 

 chamber of a nearly circular form. The water is injected into the chamber tangen- 

 tially at the circumference, and thus it receives a rapid motion of rotation. Retaining 

 this motion, it passes towards the centre, where alone it is free to make its exit. The 



