Nitro-cotton cotton pulp dewatering method

Abstract

The invention discloses a nitro-cotton cotton pulp dewatering method, relates to the technical field of nitro-cotton production, and provides a nitro-cotton cotton pulp dewatering method in which the nitro-cotton loss amount is little during dewatering. The nitro-cotton cotton pulp dewatering method comprises the following steps that 1, heavy impurities and iron chips in cotton pulp are removed; 2, the cotton pulp concentration is adjusted by adopting a concentrator to enable the concentration of cotton materials in the cotton pulp to be increased to 8%-15%; 3, the cotton pulp is conveyed to a horizontal sedimentation centrifuge; 4, the horizontal sedimentation centrifuge is started to perform solid-liquid separation on the nitro-cotton cotton pulp, and the working parameters of the horizontal sedimentation centrifuge are as followed: the rotating speed of a main engine ranges from 2000 r/min to 2500 r/min, the differential speed is 20 r/min, and the internal circle diameter of a water fender is 179 mm. According to the nitro-cotton cotton pulp dewatering method, it can be guaranteed that the wastewater solid content of a nitro-cotton product with the very small particle size is smaller than or equal to 2%o after dewatering is performed, and compared with an existing dewatering technology, the wastewater solid content is significantly decreased, and the product yield is increased.

Description

technical field [0001] The invention relates to the technical field of nitrocellulose production, in particular to a method for dehydrating nitrocellulose pulp. Background technique [0002] Nitrocellulose (nitrocellulose) is a nitrated product of cellulose, which has a wide range of uses. In the military field, nitrocellulose is the main raw material for propellant and propellant manufacturing. In the civilian field, nitrocellulose is an important raw material for paint, ink, and celluloid. Commercial nitrocellulose must contain more than 25% of water or alcohol as a phlegmatizer. Whether it is alcohol-containing or water-containing nitrocellulose products, a dehydration process is required in the production process, that is, the nitrocellulose pulp is dehydrated to a moisture content of 25%-40%. This is the dehydration process in the production of nitrocellulose. [0003] Common dehydration methods include centrifugation, pressurization and filtration. In factory produ...

AI Technical Summary

Problems solved by technology

However, because the gap between the sieve plates needs to meet the water content requirements of the dehydrated nitrocellulose, the gap between the sieve plates is generally 15-30 wires. For some special nitrocellulose products, especially products with small particle sizes, there is a large loss of product The problem is that the solid content of the wastewater after dehydration is more than 1%. Generally, 1 ton of nitrocellulose produced by dehydration produces about 10 tons of dehydrated wastewater. Every time 1 ton of fine powder products are produced, about 100kg of normal products will be lost with the wastewater, and the product yield is low.

After the dehydration wastewater settles in the recycling tank, it can only be used for the price reduction treatment of recycled cotton, which reduces the economic benefits. Moreover, because the suspended solids in the wastewater have a low specific gravity, the COD content of the incompletely settled wastewater is high, which increases the difficulty of the operation of the reclaimed water treatment station.

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