Superheating  degrees  F

Alisolute  exhaust  pressure

Effective  [X)wer

Steam  per  horse- jiower  f)er  hour,  ex-
clusion of  air-pump


40

SO

35

180

2184

2i8x

2190

2101

176. 1

175. 1

170-5

168.4

5-2

9

14.8

20

44.7

63.9

95-4

"99

32.6

32.2

20.9

18.9

1.29

1-33        I  51

1.64

172

257

417

53 «

IQ.O

17.6

»5-7

15.6

30

2200

181. 1

14.6

143 -7
17. 1
1.89
634

15-2


The  accompanying  table  gives  results  of  tests  on  a  Rateau
turbine  by  Professor  Stodola.  To  compare  with  results  from
steam-engines,  these  latter  should  be  referred  to  brake  horse-
power, with  a  mechanical  efficiency  of  0.85  to  0,90.
This  tyi)e  of  turbine  has  been  applied  successfully  to  use
exhaust  steam  from  reciprocating  engines  which  for  some  purpose
exhaust  at  atmospheric  pressure  or  into  a  poor  vacuum.  Such
application  can,  however,  be  but  local  or  accidental.
Steam  Friction  of  Rotating  Disks.  —  The  resistance  which  a
turbine  wheel  exi)eriences  while  rotating  in  steam  can  be  divided
into  two  parts:  first,  that  due  to  the  friction  of  the  smooth  disk,
and  second,  that  due  to  the  action  of  the  vanes,  which  have  an
effect  comparable  to  that  of  a  centrifugal  pump.
From  a  consideration  of  tests  made  by  Odell  f  on  cardboard
disks,  and  by  Lcwccki  {  on  a  de  Laval  turbine  wheel  driven  in

♦  SUam  TurbineSy  trans.  Dr.  L.  C.  Lowenstcin.
t  Engineerings  Januar>',  1904.         t  Zeiischr.  d.  V,  deutsch  Ing.,  1903.
eeis  and  to  drive  wheels  with       ^*^^  r-J^^or
Smooth  Wheels  ^'^^  ""^^^^    f   ^^i^ec

HP   ^  ^^■^ard

^-'« -^-th  vanes  ""'^^^  «*  ^-'^  f     1^   V

These  .or.,.   ''^   ^    a-x^'  ^^^  ^^"^  ^^--L^

^"^bines  Which  h!.^*^    i^   a.  V       ^^^*^^»e  turbiix^        *

''^^^'nesucha^tn  7^  Oxxw\^^^^um  ^vhon  idle.
