Manual of chemical technology by unknow

Author:unknow
Language: eng
Format: epub
Tags: Chemistry, Technical
Publisher: New York D. Appleton & co
Published: 1900-03-25T05:00:00+00:00

are employed, these constituting a group, or battery as it is termed. A sectional view of such a vessel is exhibited in Fig. 379 ; it is made of stout oaken staves, the vat being from 2 to 4 metres in height, and from i to i"3 in width; at a height of from 20 to 30 centimetres from the bottom of the vessel are bored, at equal distances from each other, six holes—air-holes—of about 3 centimetres ^n diameter, so cut that the inner mouth of the hole is situated a little deeper than the outer; that is to say, the holes are bored towards the bottom in a slightly sloping direction. About one-third of a metre above the real lower bottom a false bottom is placed, similar in construction to a sieve, and at a height of a centimetre above the air-holes; upon the false bottom is a layer of beech-wood shavings extending upwards to about from 15 to 20 centimetres below the upper edge of the vat. The false bottom is sometimes constructed of laths of wood, forming a kind of gridiron-like network. Before their application the wood shavings are thoroughly washed with hot water and afterwards dried. The tub

is then nearly filled with the dr}'^ wood shavings, which are next " soured." For this purpose warm vinegar is poured over them, and allowed to remain in contact with the wood for twenty-four hours, so as to cause the acetic acid to soak into the wood. At from 18 to 24 centimetres below the upper edge of the vat is fixed a perforated wooden disc, the holes of which are as large as a goose-quill, and are bored from 3 to 5 centimetres apart from each other. In order that the liquid intended to be converted into acetic add may trickle slowly, and in fine spray as it were, over the wood shavings or thin chips of wood, through the holes, strings of twine or loosely spun cotton yarn are passed so as to penetrate downwards for a length of 3 centimetres, while at the top a knot is tied which prevents the strings slipping through the holes; by the action of the liquid, dilute spirits of wine usually, which is poinded into the vessel, the twine becomes more or less swollen, and thereby obstructs the passage of the fluid so as to divide it into constantly trickling drops. The sieve bottom is fitted with from five to eight larger holes, each about 3 to 6 centimetres wide, which by means of glass tubes, each of from 10 to 15 centimetres in length, inserted and firmly fastened therein, act as draught tubes, so placed that no liquid can pass through them. The vat is covered at the top with a tightly-fitting wooden lid, in the centre of which a circular hole is cut, which serves as well for the purpose of pouring the liquid into the vessel as for the outlet of the air which enters the vessel from below.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.