Oil-based cutting waste liquid treatment and separation system and working method thereof

Abstract

The invention discloses an oil-based cutting waste liquid treatment and separation system and a working method thereof, and belongs to the field of sewage treatment by a supercritical water oxidationtechnology. According to the oil-based cutting waste liquid treatment and separation system and the working method thereof, the system comprises an oil-based cutting waste liquid pretreatment subsystem, an oil-based cutting waste liquid reaction subsystem, a cooling and pressure reduction subsystem, a nitrous oxide purification subsystem and an alkali liquor preparation and conveying subsystem, inorder to solve the problem that a traditional sewage treatment system is low in treatment efficiency, the system is more suitable for treatment of oil-based cutting waste liquid and has the functionof efficiently degrading organic matter, treated sewage can meet the water inlet requirement of the municipal sewage plant and nitrous oxide can be generated.

Description

technical field [0001] The invention relates to the field of sewage treatment by supercritical water oxidation technology, in particular to a treatment and separation system for oil-based cutting waste fluid and a working method thereof. Background technique [0002] Oil-based cutting fluid is widely used in high-end CNC lathes, milling machines, and planers because of its good lubricating properties, cooling, cleaning, anti-rust, and good stability. The performance of oil-based cutting fluid degrades after repeated use, and it needs to be replaced to form cutting fluid waste. Oil-based cutting fluid is milky white, odorless, with high concentration of organic matter (the peak can sometimes reach 200,000 mg / L), good chemical stability, and complex components, mainly containing oily additives, extrusion additives, anti-rust additives, anti-mildew additives, and anti-foam additives , metal powder and suspended solids, etc. If not treated, it will cause serious pollution to wa...

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Problems solved by technology

[0004] The waste liquid containing chlorine and sulfur will produce hydrogen chloride and sulfur dioxide gas when adopting supercritical water oxidation technology, which will cause corrosion to the equipment and affect the service life of the equipment; the waste liquid will produce salting out in the supercritical water oxidation technology, and the salt will block Equipment and pipelines affect the long-term stable operation of the system, which limits the application of this technology in industrialization

[0005] At present, the processing of cutting waste liquid is mainly carried out by the method of precipitation-demulsification-advanced oxidation, wherein the advanced oxidation mainly adopts Fenton's method (such as CN 201610503235.1), the demulsifier in the process and the hydrochloric acid in the Fenton reaction It is easy to volatilize irritating gas, causing secondary pollution to the operating environment and seriously affecting the health of operators; there are also filter residue crushing-drying-thermal analysis-oil and gas condensation-oil-water conditioning-centrifugal separation-water treatment-gas purification-residue Cooling-residue solidification treatment of cutting waste liquid (such as CN201920185291.4), this process uses distillation to decompose the organic matter in the cutting waste liquid, which requires a lot of energy and the process is long; there is also the use of demulsification -Photocatalytic oxidation-anaerobic-MBR treatment of cutting waste liquid (such as CN201610243102.5), the disadvantage of this method is that the degradation efficiency of two-stage photocatalytic oxidation is not high, anaerobic treatment is used after photocatalytic oxidation, and the anaerobic residence time is long. Due to the incomplete degradation of organic matter in the cutting fluid, the pollution of the MBR membrane will be accelerated in the final MBR process, resulting in a decrease in the membrane flux and affecting the treatment capacity of the cutting waste fluid.

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