Efficient deinking is primarily about two things: how to maximize brightness while minimizing the loss of fibers. SelectaFlot does both.
SelectaFlot flotation inline arrangement
SelectaFlot flotation - open
The pulp suspension is pumped through the multi-injectors into the flotation cells. These newly developed multi-injectors of the next generation minimize the pressure drop in the injector, hence reducing the energy demand. Inside the patented injectors, the pressure energy is used to suck air into the feed stock. The right amount of air, together with the optimized injector geometry lead to optimum bubble size distribution − the key to excellent deinking performance. Superior flow conditions inside the cell enable best results in dirt speck removal and increased brightness at lowest fiber loss.
The foam generated in the primary cells is collected in the foam trays and discharged into the foam tank. The FoamEx foam breaker is located on top of the foam tank and destroys the foam mechanically by creating a partial vacuum through rotation of the conically shaped rotor. The liquefied foam, which is heavily load-ed with ink and dirt, is discharged at the top of the cone. The FoamEx offers robust operation with the lowest energy consumption on the market.
In the secondary stage, the design of the multi-injectors differ significantly from that of the primary cells in order to account for the higher ash content as well as higher ink and dirt concentrations.
SelectaFlot flotation combines both primary and secondary flotation in one compact unit, resulting in advantages for inspection and maintenance. In order to save floor space, different configurations and cell arrangements are available, such as double-decker or piggy-back.
The output from the flotation system is controlled by the level in the foam tank, which provides the most accurate and reliable measurements. A constant level of de-aerated liquid eliminates the risk of malfunctions by the level transmitter. Precise control of the feed flows to the flotation cells and the accept flow from the secondary stage allows stable operation without any undesirable variations in performance.
