The development of technology and the progress of skill require the diversification of the quality of the sodium sulfide. Enterprises must produce different types of sodium sulfide according to different users. Taihua Industry is high-tech chemical enterprise. Its main products are pure benzene, toluene, p-tert-butyl benzoic acid, industrial sodium sulfide, anhydrous crystalline sodium sulfide and nine-hydrate crystalline sodium sulfide. The production of sodium sulfide requires high temperature and stable steam. Therefore, Taihua Industry has conducted an inspection of the same industry manufacturers and combined with actual conditions of the unit to transform the caustic soda production system in the evaporation section. At first, Taihua purchased a 2.4 million thermal oil heater at ZOZEN(YY(Q)W-2800Q) to improve utilization rate of heat energy. Later, in order to increase the coal utilization rate, Taihua purchased a 2.4million kcal thermal oil heater(YLL-2800MA(w)) at ZOZEN
