Thermal hydrolysis pretreatment device and process for high solids sludge based on anaerobic digestion

Abstract

The invention provides a thermal hydrolysis pretreatment process device for sludge with high solid content based on anaerobic digestion. The device comprises a preheating kettle, a reaction kettle and a pressure-relief kettle which are each provided with a stirring unit, and a steam supply system used for supplying steam. The device is characterized in that steam inlets (8, 15) of the preheating kettle and the reaction kettle are arranged close to the lower of side walls, wherein steam distributors in the kettles are annular wall-adhered tubes with holes which are provided with a high-temperature resistant filtering layer for preventing blockage; the pressure-relief kettle is a flash evaporation kettle with a tank body provided with a water-cooling interlayer, wherein opening time and flow rate of water in the water-cooling interlayer are controlled through a temperature-detection and flow-control interlocking unit, and a reflux-steam pipeline of the pressure-relief kettle and a straight-through pipeline of the steam supply system are in parallel connection and maintains a communication state; and stirring blades of the stirring units in the preheating kettle and the reaction kettle are of a screw coiled shape consistent with rotating direction. The thermal hydrolysis pretreatment process device provided by the invention can improve gas productivity and treatment capacity of anaerobic digestion for the sludge to the greatest extent, and reduces construction cost and operation cost; meanwhile, solid content of treatable sludge is high (12% to 15%), and content range of organic matters is broad (60% to 35%).

Description

technical field [0001] The invention relates to a thermal hydrolysis pretreatment device for high-solid sludge based on anaerobic digestion. The invention also relates to the thermal hydrolysis pretreatment process of high-solid sludge based on anaerobic digestion by using the device. Background technique [0002] The main sludge disposal methods at home and abroad include landfill, incineration, composting, and anaerobic digestion. Due to the poor shear strength of sludge, high moisture content and organic matter content, landfill not only occupies a large amount of land resources, but also causes leachate problems, and is being gradually restricted and banned; Due to the problem of secondary pollution, its large-scale promotion and application is very difficult; anaerobic digestion has become the first mainstream technology in the world because of its dual functions of recovering potential energy and reducing environmental hazards. [0003] Due to the common shortcomings...

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Problems solved by technology

[0003] Due to the common shortcomings of traditional anaerobic digestion, such as low digestion rate, long residence time (20~30d), low treatment efficiency (volatile solids (VS) removal rate of 30%~40%), etc., in order to improve this situation, in recent years A lot of research has been done on the process of anaerobic digestion of sludge

[0004] Studies have shown that the sludge anaerobic digestion reaction process is divided into three steps: hydrolysis, acidification and methanation. Among them, the hydrolysis process takes the longest time and is the rate-limiting step of anaerobic digestion. There are disadvantages such as long residence time and low degradation efficiency in the anaerobic digestion process

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