Application of Horizontal Natural-Circulation Evaporator in High Pressure CDQ Waste-Heat Boiler

Evaporator is a very important steam generator in the coke dry quenching (CDQ) waste-heat boiler. The safety of it is a crucial target to evaluate the performance of the boiler. This article introduces the function and the characteristics of the horizontal serpentine pipe evaporator, which works in a specific condition. The evaporator is installed in the down pass of the CDQ waste-heat boiler. The article also introduces the characteristics of the natural circulation boiler, which works at high temperature and high pressure. In addition, the characteristics of the evaporator have been researched, as well as the influence of the diameters of downcomer and riser on the flow rate. According to the calculating results, it is suggested that we use separators with lower resistance instead of cyclone separator with higher resistance, ensuring the steam-water separating effect. Furthermore, a compact heat exchanger, the parallel rootnumber of the horizontal serpentine tubes, is suggested to reduce the circulation resistance pressure.