Microscreening is an acknowledged technique for collecting particles efficiently and at low cost from any type of liquid. The DynaDisc is a microscreen consisting of a number of discs with the filter fabric comprising either stainless steel or synthetic material having small openings – down to 10 microns. Depending on the application, the space available and the capacity, the filter elements of the DynaDisc can be fitted either to both sides and the periphery of the discs, or to the sides only. The direction of flow through the filter elements is from the inside out, although filters with reverse direction of flow can also be supplied.
The DynaDisc consists of one or several rotating filter discs (1) permanently mounted on a central shaft. The drive system is on the opposite side to the pipe connections. The liquid is admitted into the filter through the inlet (2) and flows into the filter discs through openings in the shaft. The liquid flow is induced by the hydrostatic pressure due to the fact that the water surface of the incoming liquid inside the filter rotor is higher than the surface of the filtrate outside the rotor. If required, the filtrate discharged can be divided by means of a patented device into two phases, i.e. the pre-filtrate (3) and the final filtrate (4).
During the filtration process, a filter cake is built up on the inside
of the filter element. It is the filter cake and not the filter fabric
that serves as the filter medium for the final filtrate, which is the
reason for the high efficiency. The DynaDisc can achieve filtration
efficiencies of up to 98%. Spray pipes and nozzles (5) are provided to
remove the filter cake, which then drops down into the coarse reject
outlet trough (6) and is discharged from the filter through the reject
outlet (7). Operation of both the filter disc drive and the spraying
process can be either continuous or controlled by automatic level