Modern Dense Phase Conveying Methods

Dense phase conveying (DPF) is slow conveying, which is operated close to the respective conveying limit and with which, in general, only a limited amount of bulk materials can be conveyed stably. In order to increase operational reliability and to expand the application range of conventional dense phase conveying, DPF processes have been developed that use various additional control and action principles to support conveying. Conventional DPF is understood here as conveying in the form of highly loaded strands or as a sequence of dunes, conglobations, and/or plugs through smooth pipes without special additional devices. The most suitable bulk materials for this are located in the two hatched areas of the extended Geldart diagram. Plant designs must be very precisely adapted to the specific properties of the bulk material to be conveyed. In order to meet the requirements of plant operators for largely trouble-free conveying operation and trouble-free restarting after possible disturbances/plugs, and on the other hand, to be able to transport bulk materials that are not conventionally conveyable in dense phase, various new pneumatic conveying methods have been developed and offered on the market. Some of these are described based on their action principles, advantages and disadvantages, and recommended application areas. Subsequently, a relatively new pneumatic conveying method, the so-called FLUIDCON conveying, is presented in more detail.