Project Background & Pain Points

A land-based recirculating aquaculture farm for Atlantic salmon in Norway adopts fully enclosed breeding mode with over 10,000 cubic meters of aquaculture water, and its water circulation and temperature control system runs 24/7 all year round. As cold-water fish, salmon rely on plate heat exchangers to keep water temperature steady at 8–14°C, making heat exchange equipment the core facility to guarantee normal growth of fish schools.

The aquaculture water contains massive fish excreta, leftover feed, organic colloids and suspended particles. The original pretreatment solution combining sedimentation tanks and ordinary filter screens has insufficient filtration capacity. Tiny viscous impurities continuously flow into cold water pipelines and attach to the inner walls of heat exchanger channels within days, forming dirt and biological slime that cause pipeline blockage and reduced heat exchange efficiency, resulting in frequent water temperature fluctuations. Consequently, salmon suffer stress responses with reduced feed intake, slow growth and higher fry mortality. The farm has to shut down equipment for over 7 hours every week to disassemble and clean heat exchangers, which sharply raises energy consumption of temporary temperature control devices, and repeated start-stop cycles accelerate equipment aging.

In addition, traditional filter screens require frequent manual disassembly and flushing every day, bringing heavy operation burdens due to high local labor costs. Manual cleaning is delayed, and sludge in sedimentation tanks easily leads to secondary water pollution, creating a vicious cycle of blockage, shutdown and repeated maintenance. Therefore, the client urgently needed in-situ replaceable, online non-stop self-cleaning equipment with full automation and corrosion resistance to fundamentally solve heat exchanger blockage.

Customized LEFILTER Solution

In view of the on-site circulating flow of 1600m³/h, high organic content and slightly saline water environment, we equipped 3 sets of LFZS series brush-type fully automatic self-cleaning filters installed in parallel on the main cold water pipeline. No reconstruction of original pipelines and civil works is required to realize seamless replacement of old equipment.

The equipment shell is made of 316L food-grade stainless steel, which resists seawater corrosion and microbial adhesion, suitable for complex water environments in aquaculture. The core 80μm high-precision wedge filter screen features high structural strength and anti-fouling surface to intercept various organic impurities effectively. The cleaning cycle is triggered by high-precision differential pressure sensors. When pressure difference reaches the preset value due to dirt accumulation on screens, built-in brushes rotate 360° to sweep dirt, and the blowdown valve opens synchronously for sewage discharge. A single cleaning cycle only takes 28 seconds with uninterrupted water supply, matching the continuous operation demand of aquaculture systems.

Equipped with an intelligent electronic control system and reserved Modbus communication interface, the equipment can connect with the farm’s central control platform to realize remote monitoring, parameter adjustment and fault early warning. Seals are made of food-grade rubber without harmful substance precipitation. Sewage is delivered to tail water treatment areas through independent pipelines to avoid secondary pollution. Supported by overseas warehouses for fast supply, product delivery, installation, commissioning and operation training were completed within 9 days.

Operating Effects & Client Benefits

The equipment has operated stably for 20 months with remarkable comprehensive benefits. The frequency of heat exchanger blockage and scaling is reduced by 91%, and the cleaning cycle is extended from once a week to once every four months, greatly cutting downtime and maintaining stable water temperature. Smooth pipelines lower the energy consumption of the whole cold water system by 12%, saving electricity costs effectively.

Fully automatic operation eliminates frequent manual screen cleaning, cutting labor O&M costs by 70%. The stainless steel filter screen has a service life of more than 10 years with almost no consumable expenses. Continuous filtration of water impurities greatly improves aquaculture water quality, reduces fry mortality by 14% and fish diseases, thus cutting the dosage of aquaculture medicine. Aquatic products meet local food safety standards.

The intelligent monitoring system provides early warning of potential risks for safer and more reliable operation of the water circulation system. This self-cleaning filter fits salmon farming working conditions perfectly and solves heat exchanger blockage efficiently, acting as a practical benchmark solution for local aquaculture water treatment renovation.