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**Minor renovation completed on the oil residue extraction unit for coal-to-oil production at **Energy Group’s Chemical Company**. Author/Source: **Energy Group**; Date: 2020-08-07; Clicks: 13. On July 29, the filter at the inlet of the circulating water pump in the asphalt tank of the oil residue extraction unit at **Energy Group’s Chemical Company** was renovated, marking another step forward toward the stable, efficient, and optimal operation of this unit. The oil residue extraction unit takes the liquid asphalt from the bottom of the vacuum tower in the flash unit; it is cooled first by an asphalt pre-cooler and then by a slurry film cooler, and after entering the asphalt shaping head, it is directly cooled and shaped in water. The asphalt forming unit is the component of the oil residue extraction system that produces three different grades of asphalt products. It features three asphalt circulation tanks for low-grade, medium-grade, and high-grade asphalt respectively. The water in these tanks is pumped to a cooling tower by circulation pumps for cooling before being returned to the tanks for reuse. During the equipment commissioning, issues such as a large amount of asphalt particles in the cooling tower trays, clogging of the filter at the inlet of the circulation water pump, and damaged filter screens were identified. On one hand, this led to the cessation of circulation in the asphalt tank; insufficient cooling capacity resulted in poor formation of asphalt in the water, forcing a reduction in the feed rate. Additionally, it generated large amounts of harmful asphalt fumes that polluted the workplace environment and posed a risk to the health of the workers ； On the other hand, asphalt particles enter the pump and the cooling tower, causing wear on the impeller and blockage of the cooling tower fillers, thereby damaging the equipment. To completely resolve the aforementioned issues, the company’s technical staff took effective measures such as adjusting the slope of the inlet filter’s mesh, reducing the mesh density, upgrading the material used for the filters, changing the way the filters are fixed, and adding backwash functions to the inlet filters. These actions were taken to address the design flaws and ensure the long-term stable operation of the pump used in the asphalt tank, thereby providing a solid foundation for high-load operations and sustainable production in the future.