A method for producing nitrocellulose and a production line for its implementation

Claims

1. A method for producing nitrocellulose from cellulose-containing raw materials, including placing the raw material in a reactor, preparing the raw material by cleaning it from impurities to obtain purified cellulose by exposing it to solutions of chemical reagents in the form of acids, alkalis and water, mechanically processing the raw material, pressing, drying, preparing a nitrating solution, esterifying cellulose with a nitrating solution, stabilizing the nitrated cellulose with solutions of acids, alkalis and water, drying the nitrocellulose by alcohol pressing, characterized in that for loading into the reactor, the cellulose-containing raw material is mixed with water and placed in a wash between two layers of filter cloth to form a raw material cake, when cleaning the raw material from impurities to obtain pure cellulose, solutions of chemical reagents are passed through layers of filter cloth and the raw material cake along the shortest path, drying the cellulose is performed with compressed dried air, passing it through layers of filter cloth and the cake of purified cellulose along the shortest path,cellulose esterification is carried out by passing a nitrating solution through layers of filter cloth and a cake of purified cellulose along the shortest path, nitrocellulose stabilization with water, acid and alkali solutions is carried out by passing them through layers of filter cloth and a cake of nitrated cellulose along the shortest path, after each stage of processing the cake with liquids, it is subjected to mechanical squeezing under pressure to reduce the remaining liquid in the cake, the solutions of chemical reagents that have passed through the cake are monitored for depletion of reagents and brought to the original concentration of reagents and immediately sent for a repeated cycle, alcohol extraction is carried out in two stages by passing alcohol through layers of filter cloth and a cake of raw materials along the shortest path, with the first stage of alcohol extraction being carried out with the alcohol used in the second stage, and the second stage being carried out with strong alcohol.

2. The method according to paragraph 1, characterized in that before the chemical treatment, the raw material containing cellulose is crushed, in order to remove sand particles and other dense inorganic impurities, the crushed raw material containing cellulose, when mixed with water, is subjected to processing in a cyclone with the pulp of the cellulose raw material being discharged through the central pipe of the cyclone, and sand and dense inorganic impurities are discharged through the lower outlet of the cyclone.

3. The method according to paragraph 1, characterized in that after squeezing the cake is blown with compressed air to remove residual liquid from the cake, the air intake from the blowing is directed to the appropriate regeneration devices through cyclones.

4. A process line for obtaining nitrocellulose, including equipment for drying raw materials, reactors for cleaning cellulose from impurities with tanks for reaction solutions of alkalis, acids and water, equipment for mechanical processing of raw materials, equipment for esterification in the form of a reactor with a tank for a nitrating solution, equipment for squeezing out reaction solutions, equipment for stabilizing nitrocellulose in the form of a reactor, equipment for drying nitrocellulose with a tank for alcohol, characterized in that the reactor for all processes of chemical processing of cellulose and nitrocellulose is made in the form of a membrane filter press having an input for raw materials and an input and output for reaction solutions, filter plates and filter cloths made of filter fabric, wherein the input for filling the filter press with raw materials is made in the form of a central channel connecting the volumes between the filter cloths,and the inlet for the reaction solutions is connected to the volumes between the filter cloths and the filter plates on one side of the filter cloths, and the outlet for the reaction solutions is connected to the volumes between the cloths and the filter plates opposite to the filter cloths, the equipment for squeezing out the reaction solutions and water is made in the form of movable membranes that are an integral part of the filter plates, the equipment for mechanical processing of the raw materials is made in the form of a mill and is installed at the beginning of the process line, after the mill a tank for preparing pulp from ground cellulose-containing raw materials and water is installed, the filter press is connected by pipelines through shut-off valves to the tank equipment, and the inlet of the central channel of the filter press is connected to the tank for preparing the pulp, the inlet for the reaction solutions of the filter press is connected through shut-off valves to tanks for reaction solutions, alcohol and compressed air,and the outlet for the reaction solutions is connected by outlet pipelines to equipment for regenerating the reaction solutions, and sensors for determining the depletion of the reaction solutions are installed on the pipelines for removing the reaction solutions, the equipment for drying the raw materials is made in the form of compressed air supplied to the inlet for the reaction solutions through shut-off valves and pipes from the compressed air collector, a second container for alcohol is installed, connected through pipelines and shut-off valves with each of the cavities formed by the filter plates and filter cloth.

5. The process line according to paragraph 4, characterized in that after the container for preparing pulp of cellulose-containing raw materials, a cyclone is installed, the tangential inlet of which is connected to the pulp container through a pump, the central pipe of the cyclone is connected to the central pipe of the filter press, and the lower outlet of the cyclone is connected to a sand dump.

6. The process line according to paragraph 4, characterized in that between the reagent discharge pipelines and the equipment for regenerating reaction solutions, air cyclones are installed, the tangential inlet of which is each connected to its own discharge pipeline, the outlet from the lower branch pipe of the conical part is each connected to its own equipment for regenerating reaction solutions, and the central pipe of each cyclone is connected to the atmosphere.