Ultrasonic Cleaning: Mineral Recovery, Flotation Cells
Flotation Cells have a history of scale and soluble buildup issues on any device that are installed in the Pulp/Slurry, Froth areas. This degree of buildup and scaling, largely depends on the makeup of the ore body and for that reason is site specific.
Displacement Floats (used with level transmitters), Pressure transmitters and Conductivity probes that are immersed in the Pulp/Slurry and Froth are “passive” technologies that do not prevent these forms of soluble and insoluble buildup and so they will be adversely affected over time.
The FloLevel™ Array transducers use “active” Ultrasonic Cleaning to remove soluble and insoluble scaling and build-up.
The Ultrasonic Cleaning power produced from the Array transducers when compared to typical sonar ultrasonics is 20 – 50 times more powerful and has been designed to create a phenomenon called RAREFACTION in front of the transducer diaphragm.
When a sound wave is produced, half of the sound wave is a pressure compression component and the other half is a reduced decompression component, which is referred to as a Rarefaction effect.
Rarefaction causes the liquid to fracture in front of the diaphragm which creates microscopic bubbles called cavitation. These bubbles form and collapse which cause high powered implosions, commonly associated with Ultrasonic Cleaning. The cleaning power for the low frequency transducers used are sufficient to remove scale, grease which are both insoluble and soil, calcium, salts, etc which are soluble in nature.
If the FloLevel™ Array was turned off and build-up was to occur on the diaphragms of the transducers, the system would self-clean and remove the build-up, without the necessity of removing the Array hardware from the Flotation Cell.
Sizing the transducer frequency for the mining environment is critical. Cavitation implosion intensity for the cleaning affect in Flotation Cells needs to take into consideration, scaling and other soluble buildup issues. The cavitation intensity (bubble size) increases as the transducer operating frequency decreases. The larger the cavitation implosion intensity, the greater the power cleaning capability.
Inversely, the higher the transducer operating frequency, the smaller the cavitation intensity and therefore can only be considered for service applications that are less arduous.