Sustainable combustion of the waste is provided by the fact that in the conditions of developed design of furnace volume the flammable part of waste is continuously passing the stages of stirring, drying, partial gasification with formation of liquid, gaseous product of dissimilation and burning with sufficient amount of air.
Stability of waste conversion provides with the high ecological index of the thermal waste utilization in the developed units.
Owing to the fact that the prepared waste goes through combustion and in consequence of the effective ash discharge the more perfect combustion of the waste is taking place with formation of low toxic components. The downward stream of outgoing gases through ash remover and after-burner stimulates the effective after combustion and discharge of ash dust, so that its amount in the outgoing gases is considerably lower of the maximum allowed, regulated by the most strict ecological standards Directive 2000/76/ЕС.
The usage of the method of selective uncatalyzed remediation of nitrogen oxides NOx by injection of carbamide (urea (NH2) 2CO) to the outgoing gases
N2O3 + (NH2) 2CO = СО2 + 2Н2О + 2 N2
provides with the content of nitrogen oxides in the outgoing gases less than maximum allowed values of the most strict ecological standards Directive 2000/76/ЕС. Reducing reaction takes place in the gas phase without formation of solid and liquid resultant products. The used method is top-priority according to Geneva Convention on Persistent Organic Pollutants.
When considering the ecological aspects of the thermal processing of solid domestic waste the the specialists take special attention to the issues of persistent organic pollutant – dioxins and furfuranes (polychlorinated dibenso-p-dioxins and polychlorinated dibenzofurans – PCDD/ PCDF). The leading experts in this field consider that the formation of PCDD/ PCDF are due to incomplete combustion of halogenated waste with the temperature of 300-650ºС and the oxygen content in outlet gas is less than 5%. The high temperatures and rational content of oxygen in the products of combustion eliminate the formation of PCDD/ PCDF.
The effective aftercombustion of conversion waste product, realized in the unit developed by our Company, stimulates the independent temperature maintenance 1000-1200ºС in the combustion zone and balanced amount of oxygen within 8-11% in the aftercombustion zone of discharging line of combustion products within not less than 2 seconds that excludes the occurrence and recurrent formation of dioxins and furfurans.