Why is a rotary drum filter necessary in recirculating aquaculture systems?
Why is a rotary drum filter necessary in recirculating aquaculture systems?
In factory-based aquaculture, a water treatment system is commonly used to maintain water quality. In the process of recirculating aquaculture, most of the waste water from the farming system contains excess feed remnants and fish excrement, which are mostly in the form of suspended large particles. The excretion of aquatic organisms and leftover feed will increase the organic content in the culture water. Excessive organic matter can trigger the proliferation of organic matter-decomposing bacteria, which then compete with ammonia-oxidizing bacteria in the biofilm for space, dissolved oxygen, and nutrients.
Therefore, in some recirculating aquaculture system designs, a rotary drum filter is used first to filter and capture larger particulate pollutants, thereby reducing the biological treatment load and preventing clogging of other equipment.
Introduction and Working Principle of rotary drum filter:
The rotary drum filter, also known as the fully automatic rotary drum filter, is a drum-type screen filtration device. It is an environmentally friendly equipment designed for the solid-liquid separation of raw water, recirculated water, and wastewater treatment systems in aquaculture. It can capture fine suspended particles in the water and is also used for purposes such as raw water filtration, algae removal, and the removal of plankton in drinking water systems.
Working Principle:
The rotary drum filter works by utilizing a rotating drum for filtration. The outer surface of the drum is covered with a dense mesh screen, and all automatic devices are controlled by an external control electrical box. During operation, 2/5 of the filter mesh is submerged in water. The wastewater to be treated enters the drum axially and flows out through the mesh screen. The impurities in the water (such as fine suspended particles, solids, fibers, pulp, etc.) are trapped on the inside surface of the drum's filter mesh. When the trapped impurities are brought to the upper part of the drum, they are flushed off by backwash water on the outside of the screen, which flows into the sewage discharge channel, thus achieving the separation of solids and liquids.
When the water level drops to the position of the water level controller, the controller transmits an electrical signal to the control center. The control center then activates the drum motor and the high-pressure water pump. The drum starts rotating slowly, while the high-pressure pump ejects water through the nozzles. The high-pressure water cleans off the dirt adhered to the screen, and the impurities are collected in the sludge collection tank inside the drum. These impurities are then discharged through the sewage outlet pipe, completing the solid-liquid separation and automatic cleaning process.
Product Features of the rotary drum filter:
The rotary drum filter has a small footprint and a large filtration area, which not only saves space in the machine room but also improves filtration efficiency. It is flexible and easy to install. The micro-porous filter mesh has small pores, low resistance, and high water flow capacity, which enhances the filtration effect. The filter mesh is made of 316L stainless steel, which has strong corrosion resistance, extending the service life and making it more durable.
The rotary drum filter has a high degree of automation and can run continuously. The liquid level sensor automatically controls the backwashing process, significantly reducing the need for manual management. With a simple structure, stable operation, low energy consumption, high efficiency, and ease of operation and maintenance, the rotary drum filter is highly favored in aquaculture water treatment. It is widely used in aquaculture systems for mechanical filtration of algae and suspended solids in raw water treatment, as well as in wastewater treatment in aquaculture farms and other farming water environments.
