The section filtration discussed general laws and mechanisms applicable to filtration together with the problems encountered in connection with filter washing. In turn, this chapter is devoted to the technology applicable to the various degremont® filters.
The widely differing conditions applicable to the use of granular filter media have led to the creation of an extensive range of filters that can be classified on the basis of their hydraulic operating conditions and of their washing conditions (table 1) or even according to their operating modes (see section filter control and regulation) :
- constant rate, variable head filter;
- constant rate compensated-clogging filter with partialised siphon or valve;
- declining rate filter.