No abstract

Bag houses are often used to control particulate matters and recover valuable resources in various industries. A bag filter is the most important component in a bag house system, and thus it is important to develop the best-quality filter media and determine the optimum operating conditions of a bag house system. This study focused on particle penetrations under an operating condition of a bag house system, and investigated the relationship between dust clogging and dust penetration as a function of pressure drops across the filter medium. The results showed a minimum collection efficiency of 80% for 0.45 μm particles at the initial stage of filtration, although this quickly recovered and remained over 99.99% with a pressure drop greater than 20 mmH 2 O with a newly developed porous filter (air permeability = 5.78 × 10 −11 m 2 ). Furthermore, the recovery time depended strongly on particle size. While it was inversely proportional to the particle size at the initial stage of filtration, it showed no difference for particles larger than 0.725 μm due to its uniform dust cake as filter cleaning proceeded.

A pleated filter bag is often used to treat exhaust gas in many industrial applications, due to its fairly high dust collection efficiency and relatively low pressure drop. This work deals with the optimum pleating geometries of a pleated filter made with a newly developed PTFE/glass composite filter. It was found that pleating geometries, including pleat height and pleat pitch, directly affect the cleaning efficiency. The design index, a, which stands for the ratio of pleat height to pleat pitch, is 1.48 for optimum operation. When the a value was higher than 1.48, the pressure drop across the pleated filter medium increased, resulting in a decreased cleaning interval due to the difficulty of filter cleaning. Therefore, it is necessary that the optimum pleating geometry should be determined by employing the dimensionless parameter, a, in the design of cartridge filters.Implications: A pleated filter bag is often used to treat exhaust gas in many industrial applications due to its fairly high dust collection efficiency and relatively low pressure drop. The present paper introduces an optimum design configuration to make a pleated filter with newly developed PTFE/glass composite filter media. A dimensionless parameter that is the ratio of pleat height to pleat pitch should be considered to make the best quality pleated filter.

The high costs of ceramic and Teflon filter media for hot gas cleaning has limited their industrial applications. This paper presents a foam coating technology that can be used to produce an inexpensive and highly efficient filter for industrial applications. A new apparatus was designed and built that coats porous glass mats with liquid-phase polytetrafluoroethylene (PTFE). The machine generates bubbles, enables the formation of uniform micropores less than 45 m in diameter, and produces a product with air permeability greater than 5.5 cm 3 /cm 2