198 KANSAS UNIVERSITY QUARTERLY. 
Substituting this value for c and A! for A in (19) we have for the 
normal pressure on a moving strip of mill 
1 ¢ © » 
P,,=0.00169A1(V c?-++-v*—vcotBcosa?)V sina (en) 
; Vv tw 
" < V : 
From Fag. 3 tan @ VecE Mosh ole! = and cosa = = = 
iS Vc? +ve V c*--v" 
Substituting these in (21) we have 
(c?--v®—cvcotB)* Vy 
| 
P} 
He Or COLOOAt 
Big.) 6, 
This normal pressure P,, on a strip is shown in Fig. 5. Resolv- 
ing it into two components, one in the plane of the wheel, the other 
i i * { i 
at right angles to it, we have for Py the component which produces 
: { 1 ae ayn ae 
rotation P, ==P,,cos@. This tangential pressure multiplied by v and 
divided by 550 the number of ft. lbs. per sec. in a horse power. 
73 
2 
0.00169A sisal 
hs 
>) 1 Pde Loreal hpi’ 
Chie} re Ry cvcotf) (c? 
l-v2)4 (23) 
Equation (23) gives the horse power of a strip of one fan. To 
find the horse power of the mill we must divide a fan into such a 
number of strips that v may be considered the same for all points 
of it, apply (23) to each one of these, add these and multiply the 
result by the number of fans in the wheel. 
Equation (23) contains three variables, horse power, wind ve- 
locity and velocity of strip. If any relation between v and c be 
known by substituting this in (23) the resulting equation is a rela- 
tion between horse power and wind velocity. This general equa- 
tion then includes all the equations that can be gottten by varying 
the load on the mill. The two lb. curve, CR, for example, since 
the load is constant for it, is the relation between v and c, as well 
as the horse power for the useful load. By substituting this rela- 
