Supercritical dissolved air cavitation device for reinforcing sludge reduction

Abstract

The invention provides a supercritical dissolved air cavitation device for reinforcing sludge reduction, belonging to the technical field of municipal sewage sludge treatment. The device is characterized in that when sludge flows through a shrinking spray pipe at a high speed, air is injected into a dissolved air cavitation cavity from an air suction pipe to be mixed with the sludge, then the air and the sludge enter a primary diffusion pipe and a secondary diffusion pipe in sequence and then are sprayed into an oxidation reaction kettle from cavitation nozzles, and finally the sludge subjected to dissolved air cavitation treatment is discharged from a sludge output pipe. The supercritical dissolved air cavitation device can operate in combination with a biochemical reaction tank, a reflux and excess sludge tank or a sludge homogenization tank. The device has the beneficial effects that as a target vortex cavitation generator is combined with the oxidation reaction kettle, the conditions of supercritical wet oxidation reaction are achieved, the refractory organics in the sludge are directly decomposed into CO2, H2O and the like, and refractory organic macromolecular chains are broken into micromolecular chains and are further oxidized into fatty acids, so that the BOD (biochemical oxygen demand) / COD (chemical oxygen demand) ratio is increased, and favorable conditions are created for subsequent biochemical reaction, thus reducing the sludge; and after the device and a method are used by sewage plants, the sludge yield is reduced by 60-70%.

Description

technical field [0001] The invention relates to a supercritical dissolved air cavitation device for strengthening sludge reduction, and belongs to the technical field of urban sewage sludge treatment equipment. Background technique [0002] Urban sewage treatment plant, every 10000m 3 After sewage treatment, the amount of sludge produced (water content 80%) is about 5-10T. The sludge contains harmful substances such as pathogens, heavy metals and persistent organic substances, which need to be treated. At present, the main sludge treatment unit technologies at home and abroad, such as concentration, dehydration, incineration, landfill, anaerobic digestion, aerobic fermentation, thermal drying lime stabilization, sludge pyrolysis, hydrothermal treatment and other treatment technologies, are all sludge generation. The process technology for post-processing it, and these processing methods bring huge equipment investment and high operating costs. At the same time, secondary ...

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Problems solved by technology

At present, the main sludge treatment unit technologies at home and abroad, such as concentration, dehydration, incineration, landfill, anaerobic digestion, aerobic fermentation, heat-dried lime stabilization, sludge pyrolysis, hydrothermal treatment, etc., all belong to sludge generation. The process technology for post-treatment, and these treatment methods bring huge equipment investment and high operating costs. At the same time, secondary pollution and safety risks are unavoidable

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