Effect of coupled heat transfer on temperature distribution of a packed bed with rotary intake and exhaust

Abstract

As an effective technique dealing with low calorific volatile organic compounds emissions, the rotary flow reversal reactor (RFRR) has the high heat recovery ability and combustion efficiency. The temperature distribution uniformity of the preheated packed bed, the main component of the RFRR, is of great importance to the combustion stability during operation. The effect of coupled heat transfer on the temperature distribution of the packed bed of a RFRR during preheating process is investigated experimentally. There are four heating forms including pure radiation and coupled forms of radiation and convective heat transfer. The temperature rising rate is obviously higher and the high temperature zone (over 800 °C)is clearly wider for the coupled heat transfer with top intake. However, the top intake leads to a temperature drop over the height of 0.6 m and the high temperature over 200 °C at the bottom end. Fortunately, the bottom intake decreases the temperature level by about 100 °C of the bottom part obviously so as to reduce the exhaust heat loss. In addition, the most uniform temperature distribution along the entire the height occurs when the top and the bottom intakes are imported together. Finally, two reasonable segmented heating forms with variable intake forms or flow rates are proposed under comprehensive consideration.