Removal of dust, COV and vapour from rice production
Location: Italy. Capacity: 36.000 m3/h.
Parboiled rice processing produces air that is discharged with a high content of dust, far above the allowed discharge limits.
For an important Italian customer TECNOIMPIANTI realized a dust removal system, that allow the compliance with the environmental regulation.
The suctioned air is first conveyed to a wet quencher system to reduce and solubilise the organic fraction, husk residues and larger dust, using nozzles that spray water on the gaseous flow. Then, the gaseous effluent passes through a Venturi-scrubber, optimised for high efficiency and with devices to reduce fouling and the accumulation of material made sticky by the presence of starch, where the final removal and separation of the remaining fine dust (consisting mainly of silicates) takes place. The washing tower is made of thermoplastic material, vertical axis type, with a floating filling in which the washing liquids flow against the suctioned vapours, the vapour path is ascending. The sizing was evaluated considering the contact times suitable for the physical process and the quantities of dust present. The inlet concentration of dust is 750 mg/Nm3 and the outlet concentration is less than 5 mg/Nm3.