1. Aerosol & Particulate Research Lab109/22/2008 Fabric Filters Filtration Fabric Selection Fabric Cleaning Air/Cloth Ratio, Filtration Velocity Pressure Drop and Design Consideration Nanofiber Filter Filtration Mechanisms Reading: Chap. 6 http://exportdeck.com

2. Aerosol & Particulate Research Lab209/22/2008 Types of Filter Fibrous filter Felted filter

3. Aerosol & Particulate Research Lab309/22/2008 Types of Filter Packing density/solidity For fiber filter,  < 0.1 For woven filter,  ~ 0.3 Do filters function simply as sieves (to collect particles larger than the sieve spacing)?

4. Aerosol & Particulate Research Lab409/22/2008 Theodore & Buonicore, Air Pollution Control Equipment, CRC Press, 1988.

5. Aerosol & Particulate Research Lab509/22/2008 Shaker Baghouse Theodore & Buonicore, Air Pollution Control Equipment, CRC Press, 1988. Shaker Cleaning Parameters What are the common problems encountered?

6. Aerosol & Particulate Research Lab609/22/2008 Reverse-Air

7. Aerosol & Particulate Research Lab709/22/2008 Reverse-Air Cleaning Parameters Cleaning dust on baghouse walls by traditional sledge-hammering Pros and Cons?

8. Aerosol & Particulate Research Lab809/22/2008 Pulse-Jet How can the blown-away particles by the on-line cleaning process be collected? Felted fabric or woven fabric?

9. Aerosol & Particulate Research Lab909/22/2008 Air/Cloth Ratio Filtration velocity (average velocity) If thicker fabric is needed to sustain the high force, is its operating cost higher?

10. Aerosol & Particulate Research Lab1009/22/2008 Parallel Flow Operation How do you determine when to clean?

11. Aerosol & Particulate Research Lab1109/22/2008 Pressure Drop (Filter Drag Model) Areal Dust Density Filter drag K2K2 K1K1 K 1 & K 2 to be determined empirically (resistance factor)  P f : fabric pressure drop  P f : particle layer pressure drop  P s : structure pressure drop Time (min)  P, Pa 0150 5380 10505 20610 30690 60990 What is the pressure drop after 100 minutes of operation? L = 5 g/m 3 and V = 0.9 m/min.

12. Aerosol & Particulate Research Lab1209/22/2008 trtr tctc tftf tjtj Time Pressure pmpm Time to clean Flow rate Filtering velocity What are the parameters that affect our decision on the number of compartments to be used?

13. Aerosol & Particulate Research Lab1309/22/2008 Areal dust density Filter drag Actual filtering velocity Pressure drop

14. Aerosol & Particulate Research Lab1409/22/2008 Ex. Calculate the max pressure drop that must be supplied for the following baghouse for a filtration time of 60 minutes: K 1 = 1 inch H 2 O-min/ft, K 2 = 0.003 inch H 2 O- min-ft/grain, t c = 4 min, 5 compartments, L = 10 grain/ft 3, Q = 40000 ft 3 /min, A c = 4000 ft 2 /compartment. Nanofiber Filter Nano-alumina on microglass Argonide E-spun PAN nanofiber Dr. Wolfgang Sigmund, MSE. UF

15. Aerosol & Particulate Research Lab1509/22/2008 Filtration Mechanisms Diffusion (Lee & Liu, 1982) Lee, K.W. & Liu, B.Y.H., Aerosol Sci. Technol., 1:47-61, 1982 http://aerosol.ees.ufl.edu/respiratory/section04.html How does efficiency change wrt d p ? How to increase efficiency by diffusion?

16. Aerosol & Particulate Research Lab1609/22/2008 Impaction (Yeh & Liu, 1974) Yeh. H.C. & Liu, B.Y.H., J. Aerosol Sci., 5:191-217, 1974 (J = 2 for R > 0.4) How to increase impaction efficiency? How does efficiency change wrt dp?

17. Aerosol & Particulate Research Lab1709/22/2008 Interception (Krish & Stechkina, 1978) Krish, A. A. & Stechkina, I. B., “The theory of Aerosol Filtration with Fibrous Filters”, in Fundamentals of Aerosol Science, Ed. Shaw, D. T., Wiley, 1978. Fat Man’s Misery, Mammoth Cave NP How to increase interception efficiency?

18. Aerosol & Particulate Research Lab1809/22/2008 Gravitational Settling Total Single Fiber Efficiency Total Filter Efficiency S f : Solidarity factor How does the filter efficiency change wrt particle size?

19. Aerosol & Particulate Research Lab1909/22/2008 H = 1mm  = 0.05 d f = 2  m U 0 =10 cm/s Should we increase or decrease flow velocity in order to increase collection efficiency for (a) tobacco smoke, (b) cement dust?

20. Aerosol & Particulate Research Lab2009/22/2008 Minimum Efficiency Reporting Value (MERV) for HVAC (Heating, Ventilating and Air Conditioning) Filters http://www.mechreps.com/P DF/Merv_Rating_Chart.pdf

21. Aerosol & Particulate Research Lab2109/22/2008 Quick Reflection