Project Background & Pain Points
A large fine chemical enterprise in Chinese Mainland operates multiple synthetic reaction production lines. The total treatment flow rate of the factory-wide circulating cooling water system reaches 2000m³/h. The cooling water provides constant-temperature cooling for core production equipment including reaction kettles, large compressors and plate heat exchangers, serving as the lifeline for continuous operation of the complete chemical plant.
The enterprise’s original filtration system combined traditional quartz sand filters with manually disassembled filter screens, which brought multiple critical defects during long-term operation and severely restricted plant production capacity and operation & maintenance efficiency.
Raw water is sourced from surface water inside the plant, containing massive sediment, colloidal suspended solids and pipeline rust impurities. The maximum influent suspended solid concentration hits 200mg/L with particle sizes ranging from 0 to 500μm. Conventional sand filters have limited interception capacity, allowing fine impurities to easily penetrate the filter layer and enter the rear pipe network. Over time, this causes blockage of heat exchanger flow channels and scaling on heat exchange tubes, drastically cutting heat exchange efficiency.
According to the plant’s operation data, the rear heat exchangers must be shut down, disassembled and cleaned once a month, with each shutdown lasting over 6 hours. This forces interruption of chemical production lines, resulting in huge production losses. Frequent start-stop cycles also accelerate wear and tear of reaction equipment. In addition, manual screen cleaning involves heavy labor; the factory must assign two full-time maintenance staff to conduct daily inspections, disassembly and screen cleaning, leading to high labor costs. Traditional equipment features complicated backwashing procedures and high water consumption, causing severe water waste that conflicts with current industrial water conservation and emission reduction standards.
Furthermore, the outdated filtration equipment lacks an automatic control system with no real-time water quality fluctuation monitoring. Sudden surges in impurities will directly endanger the safe operation of high-precision reaction equipment. The client urgently required an intelligent filtration solution enabling zero-shutdown operation, full automatic control and 1:1 replacement of old equipment to fundamentally resolve three major issues: cooling water blockage, frequent production halts and high maintenance costs.
Customized LEFILTER Solution
Taking into account the plant’s 2000m³/h high-flow working conditions, water quality characteristics and three core demands – non-stop production, automatic operation & maintenance and easy renovation compatibility, the technical team of Liferlt completed on-site surveys and hydraulic simulation calculations. We finally configured 2 sets of LFZS series brush-type fully automatic self-cleaning filters installed in parallel on the main circulating cooling water pipeline. The equipment is fully compatible with the original pipeline layout, realizing 1:1 in-situ replacement of old facilities without large-scale reconstruction of civil engineering and pipe networks.
The entire equipment shell is forged from 304 food-grade stainless steel, featuring outstanding acid & alkali resistance and corrosion resistance to adapt to complex water quality and humid working conditions in chemical plants. The shell pressure resistance meets the rated pressure standard of the plant pipe network, ensuring zero leakage and deformation during long-term operation. The core filter component adopts 100μm high-precision wedge-shaped filter screens formed by integrated stamping, boasting high mechanical strength and strong pressure difference resistance, free from damage caused by impact of large-particle impurities. It can stably intercept most suspended solids and solid particles in water to guarantee stable and qualified effluent quality.
Equipped with self-developed high-precision differential pressure sensing system, intelligent electronic control unit and mechanical brushing mechanism, the equipment triggers self-cleaning based on differential pressure changes and runs fully automatically without manual intervention. Meanwhile, the equipment reserves standard Modbus communication interfaces for seamless connection with the plant’s original DCS central control system. Operation staff can check real-time equipment operating status, inlet & outlet pressure, cleaning frequency, water quality data in the central control room, and complete remote start-stop, parameter adjustment, fault alarm and other operations to build a full-process intelligent management system.
The core cleaning structure integrates built-in rotary brushes and a bottom blowdown valve. When impurities accumulated on the filter screen raise the differential pressure between inlet and outlet to the preset threshold, the electronic control system automatically activates the drive motor. The brushes rotate 360° along the inner wall of the filter screen to thoroughly strip sediment, colloids, rust and other impurities attached to the screen, while the blowdown valve opens synchronously for sewage discharge. The whole cleaning process takes only around 30 seconds, and water supply remains uninterrupted during cleaning and blowdown, perfectly matching the 24-hour non-stop continuous production requirements of chemical enterprises.
To meet the client’s demand for rapid commissioning, relying on large-scale production bases and 24-hour full-load production capacity, Liferlt finished the whole process including technical solution confirmation, equipment manufacturing, factory inspection and logistics delivery within only 8 days, delivering products ahead of schedule to help the plant complete cooling system upgrading rapidly.
Operating Effects & Client Benefits
The equipment has run stably for more than 12 months after formal commissioning, with all operating indicators meeting or even exceeding project expectations and completely eliminating all defects of the original system. In terms of filtration performance, raw water with influent suspended solids ≤200mg/L is treated by the self-cleaning filter, with effluent suspended solids steadily controlled below 10mg/L and particle interception rate ≥95%. Blockage frequency of rear heat exchangers, spray pipelines and precision valves is reduced by over 92%. The heat exchanger cleaning cycle is extended from once per month to once per quarter, greatly cutting workload of equipment disassembly and maintenance.
Production Continuity: The equipment supports online cleaning and non-stop blowdown, completely eliminating production line shutdown caused by screen cleaning and equipment maintenance. It reduces production loss of over 500,000 RMB for the plant every year.Operation & Maintenance Cost: Fully automatic operation eliminates manual disassembly and screen cleaning work. Full-time maintenance staff is reduced to one person, cutting manual maintenance workload by 80% and saving around 250,000 RMB labor costs annually. The equipment features ultra-low blowdown water consumption, with total blowdown volume reduced by 60% compared with traditional sand filters, saving about 70,000 tons of water in the plant per year with remarkable water-saving effects.
Energy Consumption & Equipment Protection: Unobstructed pipe networks and heat exchangers restore stable heat exchange efficiency, cutting steam energy consumption of the whole circulating water system by 10% and saving 800,000 RMB fuel costs every year. The stainless steel shell and high-strength filter screens are highly durable with no easily worn spare parts, requiring only regular routine inspections and boasting a service life of over 10 years.
The LFZS series brush-type fully automatic self-cleaning filter integrates four core advantages: high-efficiency filtration, intelligent control, water & cost saving and continuous production. It fully fulfills the client’s comprehensive goals of quality improvement, cost reduction, efficiency enhancement and stable production, serving as a benchmark renovation solution for circulating cooling water systems of chemical enterprises in Chinese Mainland.
