Seawater filters are widely used in seawater systems such as offshore floating production storage and offloading devices, offshore drilling platforms and marine vessels, and are mainly used to filter impurities in seawater in long-term offshore production operations.
The problems exposed by existing seawater filters are:
1. Due to the strong corrosiveness of seawater, the seawater filter itself is corroded and damaged, and the filter element is corroded and fractured, and the filter element is washed away by seawater to reduce the filtering effect of the seawater filter.
2. The sea creature adheres to the inner raft and the filter element of the filter, which causes bio-corrosion and greatly reduces the effective filtration area of the filter.
3. Due to the decrease of the filtration effect of the seawater filter, the downstream equipment of the seawater filter is faulty, and the production is shut down when the situation is severe, which greatly affects the normal production of the offshore oilfield.
4. In view of the above problems, an anti-sea biotechnology based on ultrasonic cavitation effect was adopted, and an ultrasonic seawater filter device was developed.
Ultrasonic seawater filter
Ultrasonic anti-sea is based on the cavitation effect of ultrasonic waves (when the tiny bubble nuclei in the liquid are activated by ultrasonic waves, it is represented by a series of dynamic processes such as oscillation, growth, contraction and collapse of the bubbles). At the moment of rupture, the bubbles in the liquid generate a high temperature of more than several hundred atmospheres and thousands of degrees Celsius, which can cause the attachment of sea creatures to rapidly peel off and crush the epidermal cells of sea creatures, thereby achieving the purpose of preventing sea creatures.
After the ultrasonic test tank biological living body test, the ultrasonic frequency of effectively killing marine organisms is 22 kHz, and the ultrasonic power intensity critical point is 0.3-0.5 W/cm 2 when the ultrasonic intensity is 22 kHz.
Field Application
The ultrasonic seawater filter has been installed on the offshore FPSO and tested in the field. After field application test, it is proved that the filter element and the ultrasonic vibration plate after ultrasonic use have no sea creature adhesion, and the removal effect is very satisfactory.
According to the problems exposed by the seawater filter in the actual production, the ultrasonic seawater filter was developed and passed through the actual application on site.