A kind of pulping continuous cooking method and device

Abstract

The invention discloses a pulping continuous cooking method applicable to non-wood fiber raw materials, which includes extrusion, pre-soaking and cooking, liquid extraction, concentration, thermal spraying and other steps; the feeder of the pulping continuous cooking device passes through T The type pipe is connected to the pretreatment pot, and the pre-soaked cooking sieve plate is connected to the flash tank in the pot, and the circulation pump of the pretreatment pot and the first heater are connected back to the pretreatment pot, and the bottom dilution discharge pipe is connected to the cooking pot through the discharge pump; The cooking filter sieve plate in the pot is connected to the T-shaped pipe and is connected to the cooking pot through the cooking pot circulation pump and the second heater, and the heat sprayer is connected to the replacement washing pot; the replacement sieve plate in the replacement washing pot is connected to the flash tank through the heat exchanger , T-shaped pipe, connected to the cooking pot and the dilution discharge pipe through the liquid pump; the replacement washing pot is connected to the spray pot through the cold spray device; the invention has a compact structure, improves cooking uniformity and pulp quality, and improves pulp hardness And bleachability, reuse black liquor, reduce alkali consumption, low energy consumption, realize "zero" emission of waste gas, energy saving and environmental protection; meet the upgrading and transformation of traditional equipment.

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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