벽면 캐비티를 적용한 습식 사이클론의 집진특성

Abstract

The cyclone, one of the conventional air pollution prevention facility, has lots of advantages such as the simple structure, easy to remove high inlet concentration and dealing with the particles in high-temperature gas. However, the cyclone is largely used for pre-treatment due to the low dust collection efficiency and it is difficult to eliminate the fine particles. The cyclone scrubber can handle large-capacity gas and is the excellent performance in dust collection efficiency and provide gas adsorption and dust collection in a single unit. But the cyclone scrubber has the matter as liquid entrainment and large power consumption because of lots of pressure drop. Although this problem can be prevented by installing the demister in the conventional wet scrubber, the demister should be substituted because it could be closed by particle-phase pollutant. Therefore, we need the development of wet type cyclone which has no demand in demister installation and replacement and can reduce pressure drop, the volume of waste water treatment and power consumption by using less liquid and cutting down liquid-gas ratio. We designed the wet type cyclone with wall cavity to utilize the advantages to minimize liquid entrainment and re-scattering of particles, introducing the concept of the 'black box of multi-layer multi-stage porous plate system'. The main purpose of this study is to investigate a system which can provide high collection and long-term efficiency for fine particles without a demister. The experiment is carried out to analyze the characteristics of pressure drop and collection efficiency for present system with the experimental parameters such as inlet velocity, water quantity, spray type, particle type. As a result of studies, it was shown that the pressure of the system was 33 mmH2O (dry type), and 35 mmH2O (water spray 200 mL/min) at inlet velocity 21 m/s. There was little increase of pressure drop according to spray water, but it was a very small pressure drop compared to the existing cyclone scrubber (over 100 mmH2O). The collection efficiencies of fly ash was 96.1% (spray water 100 mL/min), 96.8% (spray water 200 mL/min) at inlet velocity 21 m/s. And the removal efficiencies of SO2 was 62.5% (water spray 100 mL/min), 75% (water spray 200 mL/min) at inlet velocity 6 m/s. This system has high collection efficiency and it was able to collect dust and remove gaseous pollutants at the same time without installing a demister at low pressure drop and liquid-gas ratio.