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Successful commissioning of the plate and frame filter press at Longyu Coal Chemical’s Second Gasification Plant. Author/Source: Longyu Coal Chemical. Date: 2022-03-01. Clicks: 9. In enterprise production, environmental protection comes first! After three months of effort, to date, all three plate and frame filter presses at Longyu Coal Chemical’s Second Gasification Plant have been successfully commissioned and are now in normal operation. The plate and frame filter press is an important component of the black water treatment system in the five-ring gasification unit of the Second Gasification Plant. Its function is to remove sludge from the ash-containing wastewater from upstream processes, achieving separation of sludge and water, so as to obtain recyclable filter cakes and clear liquid. “The system was originally designed to use horizontal screw centrifuges, but as the system load changed, the separation efficiency of these devices declined and they could no longer meet the production requirements. After discussion, the company decided to replace them with filter presses. ”Song Qiang, the director of Gasification Plant No. 2, explained. It turns out that as the two five-ring furnaces operate for long periods under high loads, the solid content in the ash water increases. Since the ash water contains flocculants, the sludge remaining after separation is slippery and sticky, which reduces the efficiency of the horizontal screw centrifuge in removing this sludge. This leads to more frequent blockages, as well as issues such as intense vibrations and high current levels. If not handled properly, it can result in wastewater spreading around, posing a constant threat to the environmental safety of the facility! Faced with this serious situation regarding safety and environmental protection, Plant 2 for gasification shifted from a reactive to a proactive approach, actively seeking better methods for treating ash water. After thorough research, it was found that plate and frame filters could serve as a substitute for horizontal screw centrifuges. Without delay, and once approved, Plant 2 for gasification reversed its schedule, adopted a systematic approach to work, and actively contacted Dazhang Filtration Equipment Co., Ltd. As part of this effort, team members, manufacturers, and maintenance personnel were brought together to carry out thorough preparations; the foundations and pipelines of the gasification system were redesigned, new operating procedures were developed, and staff training was completed in advance. To date, all 3 filter presses have been successfully installed and commissioned. It is understood that a plate and frame filter press is mainly composed of a thrust plate (fixed filter plate), a pressing plate (movable filter plate), filter plates and filter frames, crossbeams (flat iron frames), a filtering medium (such as filter cloth or filter paper), a pressing device, and liquid collection tank components. The gray water flows through the filter medium (filter cloth); the solids remain on the filter cloth and gradually accumulate there to form a filter cake. The filtrate portion passes through the filter cloth to become a solid-free clear liquid. “Compared to horizontal screw centrifuges, after filtration through a filter press, the separation of sludge from water is more thorough and stable. ”That’s what Song Qiang said.