6) has many advantages, and
is probably the best of all. In smaller installations choice must be made
first between the automatic and the non-automatic principle--the
advantages most frequently lying with the latter. If a non-automatic
generator is decided upon, the hand carbide-feed or the flooded-
compartment apparatus is almost equally good; and if automatism is
desired, either a flooded-compartment machine or one of the most
trustworthy types of carbide-feed apparatus may be taken. There are
contact apparatus on the markets which appear never to have given
trouble, and those are worthy of attention. Some builders advocate their
own apparatus because the residue is solid and not a cream. If there is
any advantage in this arising from greater ease in cleaning and
recharging the generator and in disposing of the waste, that advantage is
usually neutralised by the fear that the carbide may not have been wholly
decomposed within the apparatus; and whereas any danger arising from
imperfectly spent carbide being thrown into a closed drain may be
prevented by flooding the residue with plenty of water in an open vessel,
imperfect decomposition in the generator means a deficiency in the amount
of gas evolved from a unit weight of solid taken or purchased.
Pages:
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261