[Learning from Others’ Experiences] Hainan Refining & Chemicals introduces new manhole cover sealing systems, reducing odor concentrations to below 3 parts per million

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Hainan Refining & Chemicals Installs New Type of Manhole Cover Sealing Device April 16, 2025 According to Sinochem News, Hainan Refining & Chemicals has recently introduced a newly designed sealing device for oil-containing wastewater manhole covers at its aromatic compounds processing facility, which effectively improves the ability of these manhole covers to prevent the leakage of unpleasant odors. After its installation, the concentration of unpleasant odors dropped below 3 parts per million, which is well below the **standard. 　　To continue to build a green model factory free from waste and odors, Hainan Refining & Chemicals strives for an even higher goal of having no odors on site, with all its monitoring indicators far exceeding national standards. Since the beginning of this year, they have implemented a grid-based management system for odors, and during inspections it was found that there was room for improvement in the manhole covers for oily wastewater in the tank areas of the aromatic hydrocarbon processing units. 　　The company established a team dedicated to addressing odor issues. By taking into account the actual operating conditions of the equipment, and considering the characteristics of aromatic materials such as their low quantities and high degree of diffusion, it developed an innovative \"four-stage method for preventing odors from manhole covers.\" This method involves using leftover anti-corrosion and insulating aluminum sheets to create the outer layer of the manhole covers, while inside these covers, waterproof membranes, sand, and fire-resistant fabrics are used to prevent odors from escaping. This approach creates an efficient and durable sealing system for oil-containing wastewater manhole covers, effectively blocking the pathways through which odors can spread, thereby providing a solid foundation for improving the on-site environment and ensuring safe operations. Furthermore, by using waste insulation materials as raw materials, this facility saves approximately 50% in costs compared to the integrated exhaust gas treatment manholes commonly used in the industry.