This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1891 edition. Excerpt: ...16 in. diam. Twin safety valves, each with clear passage of area = 1200 of heating surface, .. diam. ins. = 08 heating surface, sq. ft. Chimney, 13 ft. 3 ins. from rail level to top, smallest diam. ins. = 4 Varea grate, sq. ft. Steam pipe = area of piston. Air space through bars = of grate area. Fire-bars, centre depth = length; thickness, top = 3V length; thickness, bottom =-j length; end depth = f middle depth.--' Bailway Press.' SECTION XI. THE STEAM ENGINE. 377. Horse-power. Actual H.P. = 33, 000 ft.-lbs. per min. in all calculations, but the actual work of a horse is about 22, 000 ft.-lbs. per minute. Watt's nominal H.P. for low pressure engine (pressure 7 lbs. per sq. in. above atmosphere), = area sq. ins. X 7 X 128 x ty stroke ft.- -33, 000 = d in ins.2 X stroke ft. 4-47. Boulton and Watt's N.H.P. for high pressure engines, = d2-r-14 (.-. 11 sq. ins. piston per N.H.P.) Do. do. for condensing engines, = d2- -28 (.-. 22 sq. ins. piston per N.H.P.) Bourne's N.H.P. three times that of Watt, viz. for a pressure of 21 lbs. above atmosphere. In all machinery actuated by fluid pressure, the square inch, which is the standard unit, introduces a needless complication. James Watt lost a good opportunity in not establishing the circular inch as the standard.-Circ. ins. x-7854 = sq. ins. Sq. ins. x 1-27324 = circ. ins. At the present time N.H.P. is a useless commercial term, generally depending upon size of cylinder, and irrespective Sometimes N.H.P. for non-condensing engines was (i2 X y' stroke ft.--20, for simple condensing engines d2-f. 30, and for compound engines (D2-j-d?).4-33 or 30. Admiralty N.H.P. was formerly used in classifying the power of marine engines, = area sq. ins. x speed ft. per min. X 7-r 33, 000. = d ins. X speed ft...This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1891 edition. Excerpt: ...16 in. diam.
|Title||:||Handbook for Mechanical Engineers|
|Publisher||:||Theclassics.Us - 2013-09|