tailieunhanh - AIR POLLUTION CONTROL EQUIPMENT SELECTION GUIDE - CHAPTER 15

Việc kiểm soát của các oxit nitơ (NOx) bằng cách sử dụng các phương pháp nhiệt bao gồm một loạt các thiết bị. Chương này tập trung vào NOx và kiểm soát sử dụng thay đổi quá trình cháy, postcombustion phương pháp nhiệt và xúc tác, và sự kết hợp của chúng. Điển hình ứng dụng và sử dụng đốt cháy nguồn Nguồn đốt khác nhau sản xuất NOx. Nồi hơi sử dụng một ổ ghi để đốt cháy nhiên liệu và nhiệt phát hành. Nước sôi nhiệt và tạo ra hơi nước. Nồi hơi lớn hơn thường có chứa nước và hơi. | chapter 15 Nitrogen oxide NOx control Device type The control of nitrogen oxides NOx using thermal methods encompasses a variety of devices. This chapter focuses on NOx and its control using combustion modifications postcombustion thermal and catalytic methods and combinations thereof. Typical applications and uses Combustion sources Various combustion sources produce NOx. Boilers use a burner to combust the fuel and release heat. The heat boils water and generates steam. Larger boilers usually contain the water and steam inside tubes water-tube boilers surrounding a fire box. Some smaller boilers have a combustion tunnel surrounded by water fire-tube boilers . The water-tube boiler has an analog in the petroleum refinery the process heater. The process heater is used to heat or transform a process fluid for example crude oil. Analogous to the water-tube boiler the process fluid is pumped through tubes surrounding a fire box. Most boilers are heated with burners in the horizontal direction. Process heaters are often fired with the burners in the floor. However some process heaters are wall-fired and some specialty reactors such as reformers are down-fired from the roof. Process heaters may be tall round floor-fired units known as vertical cylindrical VC heaters or rectangular units known as cabin-type which are often floor fired but may also be wall-fired. Some specialty heaters such as ethylene cracking furnaces and reformers use heat to chemically transform the process fluid. This chapter is contributed by Joseph Colannino John Zink Company LLC Tulsa Oklahoma. 2002 by CRC Press LLC Gas turbines and reciprocating engines transform heat into mechanical motion. Hazardous waste incinerators use high temperatures to destroy waste products. All conventional combustion processes form NOx. Operating principles Nitrogen oxides NOx are a criteria pollutant as classified by the Environmental Protection Agency EPA . Accordingly the EPA has established National Ambient Air .