GB1226246A - - Google Patents

Abstract

1,226,246. Continuous nitration of cellulose. ETAT FRANCAIS. 24 March, 1969 [27 March, 1968], No. 15343/69. Heading C3A. Nitrocellulose is produced continuously by a process wherein cellulose is continuously passed into a first reaction zone in which it is impregnated with a sulphuric acid / nitric acid mixture with vigorous agitation and then the reaction mixture is passed to a second nitration zone in which nitration is completed with a degree of agitation which minimizes modification of the physical structure of the cellulose, the residence time of the cellulose in the first reaction zone (e.g. 1¢ to 2¢ minutes) being less than in the second reaction zone (e.g. 15 to 40 minutes). An apparatus for the above process comprises an impregnation vessel 1 and a reaction vessel 2 connected in series, the impregnation vessel comprising first 1a and second 1b tanks intercommunicating at the bottom of each tank via a connecting pipe 1c, the first tank being provided with inlets for the cellulose 1e to be nitrated and for the acid mixture 1g, the upper part of the second tank being provided with an outlet 1h connected to the reaction vessel, at least one stirring device 5, 6 located in each tank and an impeller 3 located at the bottom of the first tank opposite the connecting pipe leading to the second tank and arranged to convey the reacting mixture from the first to the second tank via the connecting pipe. The reaction vessel may be a rotating cylindrical, horizontally disposed, reactor having an internal helical band which serves to divide the reacting mixture into independent portions which are moved forward at a uniform speed while the particles are gently agitated in a plane perpendicular to the direction of movement.