Refinery circulating water is an irreplaceable process medium in refining and chemical production; its stable quality is directly related to the safe operation of the entire plant's units. However, in complex production environments, circulating water is highly susceptible to contamination by reactants, lubricating oil and leaked crude oil. Unlike conventional oily wastewater, the pollutants in refinery circulating water often showhigh emulsification, multi-component and strong fluctuationcharacteristics: the use of surfactants makes oil-water separation difficult, and high-temperature high-pressure environments make pollutants more stable.

This complexity poses a huge challenge to traditional physical oil-removal processes - not only high chemical consumption, but also difficulty in coping with instantaneous shock loads. Once treatment fails, circulating water carrying oil will backfire on production equipment, causing incalculable economic losses. Therefore, seeking a high-efficiency oil-removal technology that breaks the emulsification barrier has become an industry consensus.

Application of Coalescing Oil Separators

The coalescing oil separator uses specially designed coalescing media and the principle of coalescence to achieve oil-water separation. Its working principle: as oily wastewater passes through special polyester-fiber material, tiny oil droplets are captured and adsorbed by the fibers, move along the fibers toward intersections under fluid push and enrich, then collide and coalesce into large oil droplets, finally achieving oil-water separation.

To ensure separation efficiency, the equipment uses a bi-directional flow design combined with CFD flow-field optimization, keeping the internal flow regime stable and effectively avoiding short-circuit and circulating flows.

Technical Features and Advantages

The equipment uses high-efficiency coalescing inclined plates to enlarge oil droplet size and shorten droplet residence time, achieving efficient oil-water separation while making the vessel structure more compact. A specially designed inlet cyclone device quickly separates dispersed oil by centrifugal force, reducing the load on downstream coalescing media and preventing internal fouling.

The coalescing media uses super-hydrophilic modification technology; atomic layer deposition modifies the material surface at the molecular level, giving the media high density and high conformality. This design enables the equipment to effectively remove oil droplets with size >=20 microns, with strong anti-clogging and high stability.

Actual Application Case

The true value of a technology is ultimately tested in practice. In a circulating-water oil-removal project at a large refinery, the coalescing oil separator demonstrated excellent large-scale treatment capacity of 17,000 m3/d, showing outstanding large-scale handling capability. The equipment operated stably, and the effluent quality met design requirements, providing reliable technical assurance for the refinery circulating-water system.

Conclusion

The coalescing oil separator shows multiple advantages in refinery circulating-water treatment: a fully automatic control system ensures stable and reliable operation; a closed pressurized oil-removal design adapts to various complex conditions; a special sand-flushing system promptly removes deposits and prevents equipment clogging. These features make it an ideal choice for refinery circulating-water treatment.

As the state's requirements for industrial water discharge and recycling rates become increasingly strict, coalescing oil-removal technology, with itshigh efficiency, low energy consumption and maintenance-freecharacteristics, is reshaping the refinery water-treatment landscape. This is not only an equipment upgrade, but a key step for the petrochemical industry toward a green and sustainable future.