, 90.8 deg. C. [Footnote: Let x = the number of large
calories absorbed by the water; then 28 - x = those taken up by the gas.
Then--
1000x / 302 = 1000 (28 - x) / (26 X 0.25)
whence x = 27.41; and 28 - x = 0.59.
Therefore, for water, the rise in temperature is--
27.41 X 1000 / 302 = 90.8 deg. C.;
and for acetylene the rise is--
0.59 X 1000 / 26 / 0.25 = 90.8 deg. C.]
If the generator were designed on lines to satisfy the United States Fire
Underwriters, it would contain 8.33 lb. of water to every 1 lb. of
carbide attacked; identical calculations then showing that the original
temperature of the water and gas would be raised through 53.7 deg. C.
Provided the carbide is not charged into such an apparatus in lumps of
too large a size, nor at too high a rate, there will be no appreciable
amount of local overheating developed; and nowhere, therefore, will the
rise in temperature exceed 91 deg. in the first instance, or 54 deg. C. in
the second. Indeed it will be considerably smaller than this, because a
large proportion of the heat evolved will be lost by radiation through the
generator walls, while another portion will be converted from sensible
into latent heat by causing part of the water to pass off as vapour with
the acetylene.
Pages:
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126