공급공기 제어를 적용한 도염식 가스가마의 특성에 관한 연구

Abstract

Gas kiln is broadly being used in industry because it is easy to control the kiln temperature changing heat load temporally. And it is also low-emission equipment for the gas fuel. Gas-firing down draft kiln is designed of round inner roof and chimney which is located below the kiln in order to achieve easily homogeneous temperature distribution by natural convection. But the weak point is that the maximum temperature in kiln is low comparing with oil kiln. In order to increase the maximum temperature, it is needed to investigate the fuel and air flow characteristics and combustion phenomena near gas burner. The purpose of this study is to guarantee the homogeneity of temperature in furnace in furnace and to improve the performance of Gas-firing down draft kiln. In this paper the temperature increase in kiln by heating time, the temperature and concentrations of chemical species change near bunsen burner, and some numerical calculation of flow field in kiln were investigated by induced air change. The results were as follows ; 1. The maximum temperature in kiln was increased a little bit by increasing fuel flow rate and by opening damper, but it was not changed too much to increase the heating time. Because the kiln temperature was governed by thermal radiation after one or two hour later. 2. The combustion was stable by increasing fuel and air flow rate in this experimental conditions, and the flame length was also shorter. 3. Maximum temperature of burner downstream was about 200℃ low comparing with the experiment located out of the kiln. 4. Considering homogeneous heating in kiln, the fuel flow rate of 6ℓ/min was suitable in this experimental conditions.