What are the industrial oil-water separation equipment?

Industrial oil-water separation equipment is mainly used to treat oily wastewater and separate oil from water to meet environmental emission standards or reuse requirements. The following are common industrial oil-water separation equipment classifications and their characteristics:

1. Gravity oil-water separator

- Principle: Utilize the density difference between oil and water to separate naturally by gravity.

- Common types:

- API separator (American Petroleum Institute standard): Applicable to the petroleum and chemical industries to treat large-flow oily wastewater.

- Horizontal oil separator: Simple structure, requires regular cleaning of floating oil and sludge.

- Inclined plate separator (PPI/CPI): Increase separation area through inclined plates, higher efficiency, and a small footprint.

- Applicable scenarios: Wastewater with high oil content in oil fields, refineries, machine repair workshops, etc.

2. Centrifugal oil-water separator

- Principle: Accelerate oil-water separation through centrifugal force generated by high-speed rotation.

- Features:

- Fast separation speed, suitable for high-concentration oily wastewater.

- High equipment cost and complex maintenance (regular cleaning of the drum is required).

- Application: Ship oily wastewater, food processing (such as oil and fat factories).

3. Adsorption filtration separation equipment

- Principle: Use lipophilic and hydrophobic materials (such as activated carbon, polypropylene fiber) to adsorb oil.

- Common equipment:

- Fiber coalescer: Use multi-layer fiber filter elements to coalesce tiny oil droplets, form large oil droplets and then separate.

- Activated carbon filter: Deeply treats low-concentration oily wastewater (such as COD discharge that meets standards).

- Advantages: Suitable for fine separation of emulsified oil (particle size <20μm).

4. Flotation separation equipment

- Principle: Introduce microbubbles into the water to make the oil droplets adhere to the bubbles and float up for separation.

- Types:

- Dissolved air flotation (DAF): Good effect in treating emulsified oil, widely used in food and electroplating industries.

- Cavitation air flotation (CAF): Low energy consumption, suitable for small and medium-sized wastewater treatment.

- Features: Can be combined with chemical agents (demulsifiers) to improve efficiency.

5. Membrane separation equipment

- Principle: Oil is intercepted by membrane technologies such as ultrafiltration (UF) and reverse osmosis (RO).

- Advantages:

- High separation accuracy (can handle nano-scale emulsified oil).

- Good effluent quality, can be directly reused.

- Disadvantages: The membrane is easily contaminated, needs frequent cleaning, and is costly.

- Application: High-standard wastewater treatment in the electronics and pharmaceutical industries.

6. Electrochemical separation equipment

- Principle: Demulsification by electrolysis, so that oil droplets are agglomerated and separated.

- Features:

- No need to add chemical agents, good environmental protection.

- Suitable for highly difficult emulsified oil wastewater (such as metalworking fluids).

7. Biological treatment method

- Principle: Degradation of organic oil matter by microorganisms.

- Equipment:

- Biological contact oxidation tank: with an aeration device, used for low-concentration oily wastewater.

- MBR membrane bioreactor: Combined with membrane filtration, the effluent water quality is stable.

Selection basis

1. Oil properties: free oil (gravity separation), emulsified oil (flotation/membrane separation), dissolved oil (biological/adsorption).

2. Flow rate and concentration: API/centrifugal for large flow, flotation/centrifugal for high concentration.

3. Emission standards: strict standards require combined processes (such as gravity + flotation + filtration).

Industry application examples

- Catering industry: grease trap (gravity) + activated carbon adsorption.

- Mechanical processing: centrifugal separation + membrane treatment.

- Ship: oil-water separator (in compliance with IMO international standards).