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ENCYCLOPEDIA OF ENVIRONMENTAL SCIENCE AND ENGINEERING - PARTICULATE REMOVAL

CÁC LOẠI VÀ ĐẶC ĐIỂM CỦA VỆ SINH cân nhắc thiết bị chính ba tham gia vào việc lựa chọn thiết bị loại bỏ hạt. Làm sạch hiệu quả phải được đủ để đáp ứng các mức độ phát thải hạt mong muốn, nhưng nhiều hiệu quả vượt ra ngoài giới hạn này thấp hơn thường là không có cơ sở. Thiết bị đặc điểm điều hành, chẳng hạn như hạn chế giảm nhiệt độ và áp suất, phải có tương thích với các ứng dụng quá trình cụ thể. Yếu tố kinh tế như mua và chi phí điều. | PARTICULATE REMOVAL TYPES AND CHARACTERISTICS OF CLEANING EQUIPMENT Three principal considerations enter into the selection of particulate removal equipment. Cleaning efficiency must be sufficient to meet the desired particulate emission levels but efficiency much beyond this lower limit is usually unwarranted. Equipment operating characteristics such as temperature and pressure drop limitations must be compatible with the specific process application. Economic factors such as purchase and operating cost delivery time and reliability must also be considered. Cleaning performance of specific particulate removal equipment is perhaps most usefully expressed in the form of a grade efficiency curve. This is the relationship of dust particle size or a related property such as free-fall velocity versus corresponding collection efficiency for that size particle. Overall collection efficiency is obtained by integrating the product of weight fraction increment times collection efficiency at that particle size over the cumulative weight fraction from 0 to 1. Since collection efficiency is highly dependent on particle size this approach permits calculation of overall efficiency for any particle size distribution of dust entering the device. This is a more useful way of expressing performance than is the use of adjectives such as high efficiency or low efficiency. Representative grade efficiency curves are shown in Figure 1. The figure should not be used for design purposes because for a given type of equipment the exact placement of a curve depends on design characteristics and operating conditions. The figure is useful for preliminary screening and evaluation of relative merit of different types of collectors. Extensive coverage of operating principles and design methodology is given by Stern 1 Brauer and Varma 2 Theodore and Buonicore 3 and Licht.4 More recent comprehensive treatments have included those by Cooper and Alley5 Heumann6 and Schneller7. Manufacturers literature