US1628549A - Process for the manufacture of granular cellulose - Google Patents

Description

raemeemay 10, 1927.

NT QFFICE.

noonn. meonnnnux, or rams, rnnncn.

PROCESS FOR THE MANUFACTURE OF GRANULAR CELLU 'LOSE.

No Drawing. Application filed November 18, 1924, Serial No. 750,716, and in France November 20, 1928.

It is known that compressed or dissolved explosive or inflammable gases and explosive or inflammable liquids, can ,0 be stored without danger when absorbed in a porous 5 material with which the container is faced.

Under these conditions, there may be a certain pressure within the container which yet is safe for transport.

This is especially the case with dissolved acetylene.

Various porous materials have been proposed for this purpose; their function has become particularly onerous when flasks of dissolved gas are placed on motorvehicles where the facing is subject to shock, to vibration, and also to difierences of temperav ture; so much is this the case that minute regulations have been drawn up respecting them, especially as regards the percentage of porosity" which the material should possess, andas regards the capacity of the material of becoming rammed, which ca pacity must not be exceeded in spite of most violent blows.

Among the materials proposed are sawdust, the pith of the elder tree, etc., but in the form of; these two varieties, cellulose does not" fulfill the conditions of porosity and unalterableness.

so This invention relates to a process for v- 4 treating sawdust which transforms and gives to it the required qualities; the invention relates also:to the new commercial prod 'uctresulting from the treatment, which product really consists of calibrated porous granules of cellulose. Sawdust is first sieved through two sieves, the larger mesh sieve excluding too large pieces such aschips or pieces, while the fine 40 mesh .sieve excludes'dust'in a too fine state- 'ofdivisionf' J g It is themsu'bject to a treatment with soda lye, for exam le, having for its object, and should have or result, to remove incrusting matters such as lignines and ii onesv ofQthe wood, and to leave only hgnoeellulose; is really the first operationin the manumaterial employed.

facture of paper pulp. It should therefore be understood that the treatment may be any one of the known treatments with soda, bisulphite, etc., in a boiler or autoclave,according to the conditions of working andthe Pure cellulose in the form of light porous homogeneous granules, not attacked by ace- 5 tone, is the result of such operation.

The cellulose granules are treated in a centrifugal machme and dried, after which they are in a state suitable for storing dissolved gases. The porosity of the granules e approaches or rather less, and they are very light; v

They can be placed in containers under direct ramming, and by tampin in give an absolutely equal distributionwithout .heap- 6: ing. A kilogram may fill a3 litre vessel, and receive 500 litres of dissolved gas, leaving all freedom of exapnsion, but preventing spitting which is very dangerous, not only by the restraint it brmgs to the outlet 70 of the gas, but above all, by the" diminution of volume and the pockets resulting therefrom.- i

Thecellulose granules may be employed for other purposes than facing flasks of disi solved acetylene which is given by way of illustration only.

Having now particularly described and ascertained the nature of my said invention and in what nianner the same is to'be per- '80 formed, I declare that what I claim is i- The process, for the object specified, of treatinglsawdust, which consists in passing the same through sieyes of predetermin mesh to obtain a particular uniform size of granule dependingnhpon the purpose fdrl'- which it is desired, and sifting such aded;

sawdust to remove dust, then subjecting *granules to treatment in .an alkalinesolution, and finally centrifuging and drying the 00 .granular product lastly obtained. p

Intestimony whereof I aflixmy signatujige.

nos-En MAGONDEAUX.