Technological Solution
The specific feature of this technological procedure compared to the existing units consists in the use of simple hydrodynamic phenomena, namely both concerning the preparation of a fine dispersion of the sorbent in the carrying air flow (as early as before the entry in a combustion products pipe reactor) and as for the controlled flow and instantaneous homogenization of this mixture with combustion products without mechanical movable parts. A perfect homogenization of the whole volume of combustion products with the sorbent (2 million particles of the sorbent in 1 m3 of combustion products) is realized in a period shorter than 0.1 s. These changes in the technological solution result in a signifiant efficiency in removal of contaminating substances from combustion products.
Description of a Unit
The sorbent is batched into a gear mill by means of a screw feeder. In the gear mill the particles are treated to reach the required grain size their dispersion into transport air being provided for at the same time. Then, the mixture enters the homogenizing equipment of a combustion products pipe reactor, namely with the speed above 5 m/s. As a consequence of turbulent flow of the mixture in the pipe reactor it is possible to reach a high mutual velocity, a high number of collisions of particles as well as a large interfacial interface for the contact of gas with the sorbent. The result of these optimal sorption conditions is a high purification efficiency being close to the theoretical degree, moreover, in a relatively small volume of the pipe reactor.
The sorbent is separated from the purified combustion products in filtration diaphragms of cloth filters. The speed of flow gets significantly lower in the entrance part. Particles of the sorbent group, they agglomerate in larger groups. A new porous structure originates, into which the contaminating components are bonded irreversibly. The mass of agglomerates is low, with a wide porous structure. These characteristics enable to create an even and a strong filtrating sorption layer on the filtration diaphragm. Subsequently, in the filtration layer there are removed the last residues of contaminating substances from combustion products.
The obtained efficiency of the sorbent CHEZACARB® EKO used in a reference unit is presented with the help of the graph – the content of PCDD/F at the entrance in the sorption degree of the boiler K2 – and of the graph – the content of PCDD/F at the exit from the sorption degree of the boiler K2.
The consumption of the sorbent CHEZACARB®EKO amounts to 0.054 kg/1000 m3 of combustion products.
Machine Solution
The machine solution of the unit is conceived as a brick box, i.e. on the grounds of a set of basic machine modules. Then, it is supplied to the client as a complete set, i.e. as a packaged unit with inputs and outputs (a linkage) for the connection in corresponding waste incinerating plants.
The innovated procedure of combustion products purification can be applied practically in all types of waste incinerating plants, i.e of those applying the wet, semi-dry as well as dry technology of combustion products purification.
In dependence on the incineration process technology as well as on the technology of combustion products purification the selected brick-box system enables to choose a machine-technology set being in compliance with the technology applied in a concrete waste incinerating plant.