The rotary kiln incinerator device designed by our unit is used for activated carbon recovery, saturated activated carbon regeneration and activation and tail gas treatment. It adopts a combination of semi-dry, dry and wet methods to recycle finished products. The tail gas emission index reaches or exceeds the relevant national standards.
Activation regeneration and tail gas treatment:
Before the ignition burner is ignited, the fan is turned on and the furnace is purged for five minutes to remove the residual gas and other flammable and explosive gases in the furnace to prevent explosion after ignition; the combustion-supporting fuel natural gas is transported through the pipeline and ignited by the automatic ignition burner. The heat released by the combustion of natural gas causes the temperature of the activated rotary kiln and the secondary chamber to rise slowly; when the furnace reaches the set temperature, the pre-treated waste activated carbon is sent to the activated rotary kiln for combustion through the automatic feeding device. The waste material burns slowly in the activated rotary kiln. Using the rotation of the activated rotary kiln and the inclination of the kiln body itself, the waste slag enters the tail of the kiln while burning and is automatically discharged by the water-cooled screw conveyor.
The flue gas generated by the activated rotary kiln is collected and enters the secondary combustion system. The temperature of the secondary chamber increases to above 1100℃ under the combustion of natural gas, making the combustion more complete and achieving the effect of smokeless, odorless and no secondary pollution. The flue gas stays in the secondary combustion chamber for 2 seconds, so that the trace organic matter and dioxins in the flue gas can be fully decomposed, and the decomposition efficiency exceeds 99.99%, ensuring that the undecomposed organic components and carbon particles in the flue gas are completely decomposed at a temperature above 1100℃. The particle activation furnace is connected to a cyclone dust collector, and the powder activation furnace is connected to a multi-tube dust collector. Both flue gases enter the denitrification system through the dust collector. The urea solution with a concentration of 10% is pumped into the furnace body. In the temperature range of 800-1100℃, the NH3 produced by the thermal decomposition of urea can react and absorb with NOx to generate N2 and H20. Effectively reduce the NOx content in the flue gas. Then the flue gas enters the membrane wall boiler to recover saturated steam for use by the demander.
Then the flue gas enters the spray quenching tower, and the tap water is transported by the pressure pump and sent into the reaction tower through the double-fluid nozzle at the top of the reaction tower. The tap water is atomized into fine droplets by the double-fluid nozzle. The atomized droplets are affected by the upward hot flue gas, forming a high-density area of droplet suspension near the nozzle. By adjusting the amount of tap water, the temperature is quickly reduced to about 200℃ within 1s, thereby effectively inhibiting the regeneration of dioxins.
A dry reaction is added to the flue from the spray quenching tower to the deacidification tower, and slaked lime is sprayed into the flue to neutralize the acidic substances in the flue gas. The flue gas coming out enters the deacidification tower to remove condensed water and dust in the flue gas; a dry reaction is added to the flue from the deacidification tower to the bag dust removal, and activated carbon is sprayed into the flue to adsorb dioxins in the flue gas. Then it enters the bag filter. When the flue gas passes through the filter bag from the outside, the dust in the flue gas is trapped on the outer surface of the filter bag, thus being purified, and then enters the upper box through the venturi tube in the dust collector and is discharged from the outlet. The PLC control triggers the opening of each control valve in sequence regularly, so that the compressed air in the air bag is ejected from the hole of the blowing pipe (called primary air), and through the venturi tube, it induces the surrounding air (called secondary air) several times the primary air to enter the filter bag, so that the filter bag expands rapidly in an instant, and accompanied by the reverse action of the airflow, the dust is shaken off. The shaken dust falls into the ash hopper and is discharged through the ash discharge mechanism.
The flue gas coming out of the bag filter first passes through the G-G heat exchanger, and the flue gas outlet is heated by the waste heat of the flue gas, reducing the white fog at the chimney outlet. After the waste heat is utilized, the flue gas that has been cooled down is sprayed on the absorption tower, and the alkaline solution atomization spray is directly in contact with the flue gas, which can effectively remove the toxic and harmful substances in the flue gas. Ensure that the flue gas achieves the effect of complete combustion, non-toxic, smokeless, harmless and odorless; the flue gas heated by heat exchange is introduced into the chimney through the induced draft fan and discharged into the atmosphere.
