Updated: July 2002
High-Performance Dioxin Removal Device (Activated Carbon Packed Column)1. Outline of this device
The object of this device is dioxin included in the exhaust gas, which is mainly discharged from waste incinerators. The outline of this device is as follows: such dioxin is sucked into the activated carbon charge layers on two floors in a vertical tower and so the dioxin density can be lowered in a stable condition even if the dioxin production quantity is sharply changed.
Two floors are provided. Each floor consists of several pieces, is reversible and ventilated. Particle activated carbon is uniformly put in layers on each floor.
Exhaust gas flows into the suction tower from its bottom or top. While the exhaust gas has been passing through the activated carbon layers on two floors, the harmful gas components including dioxin are sucked and removed.
Activated carbon is supplied to the suction tower as follows: activated carbon is carried by the supply conveyor from receiving hopper to the top of suction tower and is supplied to the upper floor by the throwing seal valve. While the activated carbon is being dropped into the upper floor, the dispersing device arranges it in a uniform thickness. When the supply to the upper floor has just been completed, the upper floor is reversed to move the activated carbon into the lower floor. The upper floor is made horizontal again and activated carbon is supplied into it again. This sequence is executed without blowing gas.
A safety system is provided to prevent the activated carbon from ignition. This system always monitors the temperature in the suction tower inlet gas and in the activated carbon layers. If the temperature at one of these places is abnormal, the emergency cutoff/nitrogen gas fire extinguishing system is actuated.
2. Features
(1) Because the fixed layer type is employed, dust, which is generated by breaking the activated carbon while gas is being blown, is reduced.
(2) Because of the vertical gas flow, the installation area can be reduced.
(3) Stable removal efficiency can be obtained even if the dioxin density at the inlet is changed.
(4) This device can easily be installed after an existing dust collector.
(5) There is no operating unit while gas is being blow and so mechanical trouble is reduced.
(6) An emergency fire extinguishing system, which supplies nitrogen gas, is provided against an ignition trouble of activated carbon.
3. Performance
Dioxin density at the outlet is kept within 0.1ng-TEQ/m3N level even if the density at the inlet is changed. It means that this device meets the strictest exhaust standard correctly. Moreover, it is already confirmed that this suction removal device is effective for another harmful component, mercury.
(1) Dioxin removal rate: 95% or more
Performance data
Inlet [ng-TEQ/m3N] Outlet [ng-TEQ/m3N]
0.19 0.0035
1.6 0.037
97.0 0.071
(2) Mercury removal rate: 85% or more
Performance data
Inlet [mg/m3N] Outlet [mg/m3N]
157.0 19.0
112.0 11.5
4. Application and object
(1) General waste incinerator
(2) Industrial waste incinerator
(3) Sintering furnace (metal refining)
(4) Electric furnace (metal refining)
(5) Calcinating furnace (metal refining)
(6) Blast furnace (metal refining)
(7) Melting furnace (metal refining)
