Explosives . 11). After fastening downthe man-hole the stirringmechanism is started and theretort is gradually heated Ixiiiir taken to avoid over-heating as far as possible, as itcauses the formation of tar andcoke, and a corresponding di-minution of the yield of i> not practicable to dry thewhole of the moisture out of theacetate before charging it intothe retort, as acetone begins tobe given off even at a moderate temperature. Consequently the first run-nings of the retort consist of water with only a little acetone. The decom-position of the acetate doe- not become act
Explosives . 11). After fastening downthe man-hole the stirringmechanism is started and theretort is gradually heated Ixiiiir taken to avoid over-heating as far as possible, as itcauses the formation of tar andcoke, and a corresponding di-minution of the yield of i> not practicable to dry thewhole of the moisture out of theacetate before charging it intothe retort, as acetone begins tobe given off even at a moderate temperature. Consequently the first run-nings of the retort consist of water with only a little acetone. The decom-position of the acetate doe- not become active until the temperaturereaches about 380c c. ; the bulk of the distillate come- over between 380and 400 C. At the end of the distillation steam ia blown through to remove the last portion of the distillate, and to render the residue in the retort non-inflammable. Attempts have been made to heat the retort- in a bath of lead in order to make the heating more uniform and so improve the yield, but trouble was. Fig. 67. Acetate of Lime Still, SOLVENTS 343 caused by the oxidation of the lead, with the consequence that heat was lost,and the special object of the bath was not attained. Heating in a streamof superheated steam has also been tried : a better yield is thus obtained,but the consumption of fuel by this process is considerably greater ; more-over, it is only possible to work sifted, dust-free acetate, which makes itvery expensive. Anotherprocess, that has beentried and abandoned, wasthe conversion of theacetic acid of the crudepyroligneous acid directlyinto acetone without thepreliminary formation ofacetate. This was doneby passing the acid overheated baryta or plant was erected onthis principle in WoolwichArsenal, but it did notprove successful, and wassoon abandoned. Theyields by this process werevery poor ; the crudeacetone was mixed with much unchanged acetic acid, which had to be recovered and worked overagain. Recently an improvement has been effected by heati
Size: 1451px × 1722px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidexp, booksubjectexplosives
