THE MECHANICAL HANDLING OF MATERIALS 341 h.p. in such a case is increased by 13 per cent, above that required for driving a similar conveyor which has no change of direction.
If this treatment is applied to the examples already considered in connection with the first senes of formulæ given it will be noted that the horse-power required works out at a higher figure. The difference between the examples represents, thereiore, the additional horse-power absorbed by the new factors which have been mtroduced. For example :—■
Horizontal conveyor, capacity, etc., as in previous example (p 339) •__ HP __ 1’4 L (25 S + 37 C)
33,000
= 1-4 X 100 (25 x 40 + 37 x 20)
33, 000 ~
__ 140(1000 + 740)
33;(W)
= 7-38
Partially indined conveyor, rising at 30° with. the horizontal
H .P. required to lift material up incline of 30° to height of, sav 10 feet
37 CA 37 x 20 x 10
33,000 33,000
Total H.P. = 7’38 + 0'22 = 7’6
Increase of h.p. = 13 per cent.
13 per cent, of 7-6 — 0-988
Total h.p. required = (7-6 + 0-988)
= 8-58
• the t.examPIes for similar conveyors (worked out on p. 338) it will be
noted that the otter treatment gave results of 6’44 and 671 h.p. respectively.
, lhe f°llowmg table (Simmer) gives a comparison between the relative power h S°J S. Various tyPes of conveyors. la each case the conveyor is assumed to øe ot öO tons per liour capacity, and to liave an effective length of 100 feet
H.P. Required for Convbyoks Band conveyor for light materials .... Band conveyor for coal Swinging conveyor Push-plate conveyor Worin conveyor Tubulär worin conveyor
5-0 to 8-0 „
• 12-8 „ . 18-38 „ . 25-0 ..