Verfahren zur elektrischen Abtrennung von Staub

摘要

Dust particles in an electrostatic separator are coated by treating them with phosphoric acid to improve their electrical conductivity and thus enable the gas ions from the emission electrode to pass through the dust on the precipitation electrode p and avoid a corona-effect on that electrode. A component of phosphoric acid, at a higher temperature than that of the dust particles, can be added to the gas-stream in a wide range of concentrations and in different ways. One way is to burn yellow phosphorus at the entrance to the separator to produce phosphorus pentoxide which condenses on the particles and in the gas-stream to form phosphoric acid or form droplets of pentoxide coated with phosphoric acid; the combustion of the phosphorus can be modified by varying the air supply and adding varying amounts of water vapour. The phosphorus can also be burned purely with water vapour whereby phosphoric acid plus phosphine are formed.