A treatise on waterworks for the supply of cities and towns : with a description of the principal geological formations of England as influencing supplies of water / by Samuel Hughes.

  • Hughes, Samuel
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on waterworks for the supply of cities and towns : with a description of the principal geological formations of England as influencing supplies of water / by Samuel Hughes. Source: Wellcome Collection.

    411/484 page 393
    Table VI. Horse-Power of Cornish Steam-Enoines. Bxj Mr. John Darlington. The following Tal>le has been compiled with the object of furnishing an approximate value of the power in horses rendered by Cornish Pump- ing Engines having cylinders from 15 to 100 inches diameter. The elements employed for the calculations are those most usual with Cornish engineers; and the effective horse-power per stroke is given, that the in- quirer may ascertain the total value of horse-power resulting from work- ing any given number of strokes per minute. The steam in most of the Cornish Pumping Engines is only permitted to act on one side of the pis. ton; hence such mode of working is technically termed single acting. Recently however it has been considered that equal economy is obtained by introducing the steam on both sides of the piston, and a few engines are in operation on this principle. The horse-power of such (double- acting) engines may he found by doubling the results given in the Table. Horse-Power, Load in Pounds, and Speed per Minute of Cornish Single Acting Exjmnsive Steam Pumping Engines, having Cylinders from 15 inches to 100 inches diameter. Initial Pressure of Steam, 30 lbs. per sq. inch. Temp. 251 -6°. Full Pressure of Steam, l-4th of stroke.—Mean Pressure of Steam, 17-8 lbs. less l-5th friction = 14-24 lbs. c ■ ... In. 15 16 17 18 19 20 21 22 23 24 25 2G Ft. 8 9 9 9 9 9 9-5 9'5| O — ►J Strokes per Minute. In. 176-71 201-06 226-98 254-46 283-52 31416 346-36 380-13 415-47 452-39 490-87 530-93 lbs. 2,516 2,863 3,232 3,623 4,037 4,173 4,932 5,413 5,916 6,442 6,989 7,560 5 5 5 5 5 a a n Speed per Minute in Feet. 14 14 14 14 1 i 12 12 12 12 12 II! 1(1 Ft. 80 80 80 80 80 81 81 81 81 81 85 A 85A to Ft. 224 224 224 224 224 216 21G 216 216 216 200 200 Horse Power. s-s 304 3-47 3- 91 4- 39 4- 89 5- 48 6- 05 6- 62 7- 26 7-90 9-05 9-79 9 10 12 13 1 1 16 17 1!) 21 21 22 s 8 •53 71 96 •1'.) •70 ■63 1 1 71 36 OS 17 90 IB 'n > v to s Ho •609 •691 •783 •878 •978 1-219 1-345 1-476 1-613 1- 756 2012 2- 176
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