Updated: July 2002

1. Purpose

The DC-21 system is an exhaust gas treatment system which highly efficiently removes soot and dust, and harmful gases (hydrogen chloride, sulfur oxides, etc.), and in addition, dioxin contained in exhaust gas discharged from waste incinerators, urban refuse incinerators, metal melting furnaces, boilers of various kinds, etc. Hence, it is foundational equipment that prevents environmental air pollution, thereby improving the environment and protecting the health of inhabitants.

2. Characteristics

1. Dioxin restraint effect by use of a quenching tower
2. Chemical agent storage and supply device (slaked lime and activated charcoal), inclusion of caking prevention mechanism based on fine particle engineering, realization of stable supply, and uniform dispersion system
3. The bag filter clears the control value completely.
Measures to prevent dew condensation (corrosion) by using a heater, etc.
With the most suitable filter selected, a long life is realized.
4. With the adoption of a high-efficiency fan, the exhauster provides an energy-saving effect and meets the requirement for use at high temperatures.

3. Performance

1. Soot and dust
- Removal rate: 99.9% or more
- Discharge concentration: 0.05 g/m³ or less
2. Harmful gases: Removal rate 95% or more
3. Heavy metals: Removal rate 95% or more
4. Dioxins
- Removal rate: 90% or more
- Discharge concentration: Control standard or below

Fig. 1 shows the flow of the system.

4. Applicable fields and objects to be treated

1. Urban refuse incineration facilities
2. Industrial waste incineration facilities
3. Medical waste incineration facilities
4. Boilers of various kinds

5. Others

The DC-21 system can be used with the following as peripheral equipment.
1. Activated charcoal adsorption tower
2. Catalytic reaction tower
3. Device for rendering ashes harmless
4. Measuring equipment (CO-O2 analyzer and HCl analyzer)
5. The DC-21 system can be retrofitted to existing furnaces, and preparations are being made for the system to be used with furnaces to be installed newly.