Thermodynamic analysis of the burning of organic waste liquid in a fluidized bed incinerator

With coal serving as an auxiliary fuel heat balance equations were established for the burning of organic waste liquid in the dense-phase zone and rare-phase zone of a fluidized-bed incinerator. By solving for these equations determined were the following: 1. The ratio of waste liquid being incinerated in the dense-phase zone as calculated against the total incinerated quantity; 2. Characteristics curves showing the effect of the incineration temperature in the dense-phase zone, excess air factor at the furnace outlet and the preheating air temperature on the consumption of the auxiliary fuel and the furnace outlet temperature. The results of calculation indicate that with the ratio of the waste liquid incinerated in the dense-phase zone being kept at 70% of the total incinerated quantity the temperature in the dense-phase zone can be roughly maintained at the same level as that at the furnace outlet. Moreover, it is highly desirable to control the dense-phase zone temperature at 850 - 900°C in order to reduce the consumption of auxiliary fuel and to limit the excess air factor at less than 1.7 in order to maximize the preheating air temperature. The above findings can serve as a theoretical basis for the design and operation of fluidized bed-based waste liquid incinerators.