Legislation Disc Cracker Waste Tire Pyrolysis Process Heat And Mass Transfer Model

After the investigation of twenty years, thermal pyrolysis technology is considered as one of the perfect methods of recycling used tires. But it is only limited in a laboratory scale up to date and industrial trials are relatively new due to the great difficulty in the design of large-scale pyrolysis reactor. A new erect cracking furnace as the pyrolysis reactor is developed in this paper. Based on the pyrolytic mechanism of used tires and experimental results of industrial-scale equipment, a mathematical model for the heat and mass transfer in this type of pyrolysis plant is presented, and the design and optimization procedures of several operation parameters are obtained as well. The main research contents are following as:A trial on a laboratorial scale and a pilot unit on the industrial scale (3000 tons per year) have been constructed, and the industrial trial has been performed successfully. The main problem during the experiment is given along with their solving measures. Many test data, which are very important to validate the following mathematic model, are also provided.A mathematical model for the heat-mass transfer in the pyrolysis plant is presented. The formulas for several important parameters, such as height, volume of each granular heap and retention time, are provided along with several assumptions. According to the penetration model of particle heat transfer and kinetic model of tire pyrolysis reaction, the leaving temperature(Tout) and rubber remnant content(Xout) in granular heaps are effectively predicted by a straightforward stepwise calculation procedure. According to the model, The optimization of this equipment should aim at the maximizing of the effective covering ratio( μ )and the total area-averaged heat transfer coefficient( α ), and the special design and optimization procedures of several crucial operation parameters are given. The model and equations were applied in the industrial experimental plant. In the result, the theoretical predictions are shown to be in satisfactory agreement with experimental data. The calculation formulas for the similar structure ?the continuous plate dryer are also obtained.The innovations of this paper can be concluded as following: a new model of mass transfer in the cracking furnace is developed. The calculation formulas for several important operation parameters are provided; secondly, the mathematic model of the heat transfer is also provided along with the three simplifying hypothesis. The iterative calculation formulas for each granular heaps are obtained; thirdly, the application of this new model and formulas to the continuous plate dryer are studied. The result of calculation example shows that the model can simulate the drying process with an error less than 20%.