A Research And Design Of A New Tunnel Kiln For Silica Bricks

The results of analysis and research on the tunnel kiln of Luoyang Refractory Group Cooperation, which is long for 202.5m,have been used in the design of the new tunnel kiln. In the design,the following advanced experiences for the tunnel kiln from all the world were adopted: structure form and lining material selecting, selecting of burning system in sintering zone, decreasing the temperature difference in preheating zone between the top and bottom of kiln, internal pressure balance and using of lower heat storage kiln car. By these measures the new tunnel kiln ,which is long for 164.7m,have been put into operation for nearly one year.It has been proved that various performances meet the requirement of sintering for silica bricks. The ratio of qualified products is over 97 percent, which achieves the expected goal of of the design.The research on tunnel kiln indicates that through the widening of the section of the kiln,temperature difference between top and bottom of the kiln, especially in the preheating zone, can effectively be shorted down, so that the laminating in the heating flow can be radically put down. The service life of the kiln may be increased by the right selection of internal lining materials. It is critical for decreasing the temperature difference by setting up the recycle gas curtain. Efficient burners used in the sintering zone have distinctive effects on the uniforming temperature in kiln and on the energy saving. The high-speed air sprayed by the burners bring out a strong stirring and heat convection. Pressure-balance system installed on the bottom of the kiln stabilizes the temperature condition and pressure condition. The using of lower heat-storage kiln car has effects on saving energy. Air-ducts setting up at the bottom of setting bricks have positive effect on improving internal air flow and temperature distribution.Conclusions can be drawn from the whole design that large section area, lower chamber and high-speed burning spout should be applied to modern tunnel kiln. It is indispensable to install gas-recycling system in preheating zone,to set a pressure-balance system at the bottom of the kiln and to lower the heat storage of the kiln car as well as to set up an air ducts at the bottom of setting brick.