Pulping continuous cooking method and device

Abstract

The invention discloses a pulping continuous cooking method applicable to non-wood fiber raw materials. The pulping continuous cooking method comprises the steps of extrusion, presoaking cooking, liquid extraction, concentration, hot spraying and the like. A feeder of a pulping continuous cooking device is connected with a pretreatment pot through a T-shaped pipe, a presoaking cooking sieve plateis arranged in the pot, connected with a flash tank and connected back with the pretreatment pot through a pretreatment pot circulating pump and a first heater, and a bottom dilution discharging pipeis connected with a cooking pot through a discharging pump. A cooking filter sieve plate in the pot is connected with the T-shaped pipe and is connected back to the cooking pot through the cooking potcirculating pump and a second heater, and a hot spraying device is connected with a replacement washing pot; a replacement sieve plate in the replacement washing pot is connected with the flash tankand the T-shaped pipe through a heat exchanger, and is connected with the cooking pot and the dilution discharge pipe through an infusion pump; the replacement washing pot is connected to a spraying pot through a cold spraying device. The pulping continuous cooking device is compact in structure, improves cooking uniformity and paper pulp quality, improves pulping hardness and bleachability, recycles black liquor, reduces alkali consumption, is low in energy consumption, achieves zero emission of waste gas, saves energy and protects the environment. And upgrading and reconstruction of traditional equipment are met.

Description

technical field [0001] The invention relates to the field of chemical and environmental protection, in particular to the field of papermaking industry, in particular to a continuous cooking method and device for pulping. Background technique [0002] Alkali method and kraft method are the current mainstream pulping and cooking methods. In the late 1970s, the deep delignification theory proposed by Swedish scholars Hartler and Teder further improved the displacement cooking technology based on wood fiber raw materials, and made significant progress, such as Camille vertical continuous cooking Modified Continuous Cooking (MCC), Extended Improved Continuous Cooking (EMCC), Low Solids Cooking (LSC) and Rapid Displacement Cooking (RDH) in Vertical Pot Batch Cooking, Super Cooking and Displacement Cooking (DDS), etc. Most of the existing displacing cooking pot systems usually adopt a replacement form in which liquid enters from the bottom of the cooking pot and liquid exits from ...

AI Technical Summary

Problems solved by technology

The flakes of grass raw materials are small, and they soften prematurely during the cooking and heating process, resulting in increased bulk density and increased filtration resistance, making it difficult to achieve uniform replacement and heating. Moreover, due to the uneven density of the pot, during the replacement process, The cooking liquid will short-circuit at the lower density, resulting in uneven temperature of the raw materials and affecting the quality of the final displacement cooking

Recently, some scholars have used the RDH batch cooking technology and super cooking method in the batch displacement cooking system to conduct small-scale experiments on rice straw and wheat straw fibers with a large liquid ratio cooking process. Although this method can improve the quality of pulp and reduce the hardness of pulp, During the steaming process, the black liquor can be reused many times, and it can save energy, reduce sewage discharge and be beneficial to environmental protection. Continuous production

[0004] At the same time, although displacement cooking technologies based on wood fiber raw materials such as Camille vertical continuous cooking and DDS cooking have been applied in the production of bamboo pulp and wood pulp, they have poor adaptability to raw materials and high investment costs. , complex automation control and subsequent high maintenance costs, etc., make it impossible for small and medium-sized pulping enterprises to consider, so they have to choose traditional intermittent cooking methods such as steaming balls and steamers with high energy consumption and open exhaust gas discharge, or horizontal tube continuous cooking. method, seriously restricting the development of enterprises

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