, ammonia and
sulphuretted hydrogen, in the generating chamber itself. To prevent the
loss of acetylene by dissolution, carbide-to-water generators are
occasionally fitted with a reaction grid placed only just below the
water-level, so that the acetylene has no more than 1 inch or so of
liquid to bubble through. The principle is wrong, because hot water being
lighter than cold, the upper layers may be raised to the boiling-point,
and even converted into steam, while the bulk of the liquid still remains
cold; and if the water actually surrounding the carbide is changed into
vapour, nearly all control over the temperature attending the reaction is
lost.
The hand-fed carbide-to-water generator is very simple and, as already
indicated, has proved itself perhaps the best type of all for the
construction of very large installations; but the very simplicity of the
generator has caused it more than once to be built in a manner that has
not given entire satisfaction. As shown at L in Fig. 6, p. 84, the
generator essentially consists of a closed cylindrical vessel
communicating at its top with a separate rising holder. At one side as
drawn, or disposed concentrically if so preferred, is an open-mouthed
pipe or shoot (American "shute") having its lower open extremity below
the water-level.
Pages:
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172