Oily sludge treatment equipment

Oily sludge refers to a mixture of oil, water, solid particles and other pollutants generated during the process of oil extraction, refining, storage, transportation and use. It is very challenging to handle due to its high oil content, high toxicity and high viscosity. Oily sludge treatment equipment is specially designed to treat this type of special sludge to achieve the goals of reduction, harmlessness and resource utilization. The following are several common oily sludge treatment equipment and their working principles: 1. Horizontal screw centrifuge The horizontal screw centrifuge uses the centrifugal force generated by high-speed rotation to achieve solid-liquid separation. After the oily sludge enters the centrifuge, the solid particles (including oil sands) with a larger specific gravity are thrown to the inner wall of the drum under the action of centrifugal force to form a solid phase layer, while the oil-water mixture with a smaller specific gravity forms a liquid phase layer. The screw conveyor rotates coaxially with the drum, but at a slightly faster speed, pushing the solid phase layer to the small end of the drum, while applying a squeezing effect to further dehydrate. The liquid phase is discharged through the overflow port at the large end of the drum. Centrifuges can achieve continuous feeding and continuous separation, with high processing efficiency, and are often used for the preliminary separation of oily sludge. 2. Pyrolysis equipment Pyrolysis technology is to heat the oily sludge at high temperature in an oxygen-free or anoxic environment to cause the organic matter to undergo thermal cracking reaction and convert it into oil, gas, combustible gas, tar and solid residue (semi-coke or biochar). Pyrolysis equipment includes components such as pyrolysis furnace, oil and gas condensation separation system, and flue gas purification system. The pyrolysis process can not only greatly reduce the volume of sludge, but also recover valuable energy, while converting harmful organic matter into relatively harmless solid residue, realizing resource utilization and harmlessness. 3. Hot washing equipment The hot washing process usually uses high-temperature steam to directly contact the oily sludge, and uses the heat energy of the steam to distill the oil from the sludge. At the same time, chemical agents (such as surfactants) are added to improve the oil-water separation effect. The washed oil-water mixture is then separated from the oil and water by an oil-water separator (such as gravity sedimentation, centrifugal separation or membrane separation equipment). Hot washing equipment is suitable for treating oily sludge with high oil content, high viscosity and severe emulsification. 4. Bioreactor Bioreactor (such as anaerobic digester, aerobic bioreactor) uses the biodegradation of microorganisms to treat oily sludge. Under anaerobic conditions, microorganisms convert organic matter into biogas (mainly methane and carbon dioxide) and stable sludge residues; under aerobic conditions, microorganisms convert organic matter into carbon dioxide, water and microbial cells through oxidation. Biological treatment is suitable for oily sludge with high organic content and low toxicity, and can also produce clean energy (biogas) and biofertilizer. 5. Chemical demulsifier treatment system Chemical demulsifier treatment system uses chemical agents to destroy the emulsified structure in oily sludge and improve the oil-water separation effect. After the demulsifier is mixed with the oily sludge, it promotes the aggregation and growth of oil droplets through stirring, heating and other means, and then separates the oil, water and solid phases through gravity sedimentation, centrifugal separation and other equipment. This method is suitable for treating oily sludge with serious oil-water emulsification, but the cost of using chemical agents and the disposal of waste liquid after treatment need to be considered. 6. Mechanical dehydration equipment such as belt filter press, plate and frame filter press, screw dehydrator, etc. are used to deeply dehydrate the oily sludge after preliminary treatment. Most of the water in the sludge is removed by physical pressure or centrifugal force to reduce the water content and form a mud cake that is convenient for subsequent treatment or disposal. Mechanical dehydration is usually the last link in the oily sludge treatment process to ensure that the sludge meets the water content standards required for subsequent disposal such as landfill, incineration, and resource utilization. 7. Incinerator For oily sludge containing high concentrations of harmful substances or not suitable for resource utilization, an incinerator can be used for high-temperature incineration. During the incineration process, organic matter is completely oxidized into carbon dioxide and water, inorganic matter is retained in the form of ash, and harmful substances are destroyed by high temperature to achieve maximum reduction and harmlessness. The heat generated by incineration can be recycled, but a complete flue gas purification system is required to ensure that emissions meet the standards. In summary, there are various types of oily sludge treatment equipment, including physical separation equipment (such as centrifuges, filter presses), thermal treatment equipment (such as pyrolysis furnaces, hot washing equipment), biological treatment equipment (such as bioreactors) and chemical treatment equipment (such as demulsifier treatment systems). In practical applications, it is often necessary to select or combine different equipment and technologies according to the specific properties, treatment objectives and environmental protection requirements of oily sludge to build an efficient, economical and environmentally friendly oily sludge treatment system.