Filters comparison

Fig. 44. Multichannel dynamic ash model. Simulation of additive ash accumulation at the end of the filter. Comparison with X-ray images of Blanchard et al. (2004) (see Plate 17 in Color Plate Section at the end of this book).

Figure 11.19— Visual colorimetry. To the left, a rotating filter comparison system. By using two cells, one of which contains the sample and the other the blank, it is possible to take into account the normal coloration of the two lubes. Observation is made by comparing the transparency for a specific filter against white light. To the right, a portable reflectomeler that allows comparisons to be made without the human eye. (Reproduced by permission of Merck.)...

These factors combine to make impactors less precise and accurate than filters. Very few comparisons have been made between sizing impactors and those that have provided mixed results. The 1977 Environmental Protection Agency-Department of Energy Sampler Intercomparison included the Multi-Day Sampler, which performed well ( 15%) for fine aerosols such as sulfur, lead, and zinc (15). The 1986 Carbonaceous Species tests at Glendora, California, included the DRUM sampler. It performed well for sulfur ( 18%), as compared to the fine filter sampler (PM-2.5), but no other sizing impactor was available for comparison and no element other than sulfur was reported. DRUM versus filter comparisons were reported as part of the Southern California Air Quality Study of 1987 (2). Again, no other impactor was available for comparison, and the comparisons with filters were only fair (r2 0.7 r, linear correlation coefficient). 

Wilson, EC. B. Haas, J. C. (1994) Granular-bed and ceramic candle filter comparison for advanced power systems. In Proceedings Eleventh International Pittsburgh Coal Conference, Vol, 1, pp. 131-136, Pittsburgh, PA. 

Hekmat M, Latawiec A, Smith R. 1994. Determination of coal tar pitch volatile materials on air sampling filters Comparison of gravimetric and spectroscopic methods. J Am Ind Hyg Assoc 55(10) 942-945. 

Although this technique is widely used to characterise pore size, other techniques are also used, not least amongst which are challenge tests (see Rideal, 2005) in which the filter medium is challenged by a quantity of calibrated micro-spheres, which are fluidised, typically by sonic means, to assist in their passage through the filter. Comparison is then made of the particle size distribution of the micro-spheres before and after filtration. 

Comparison of the measurements with the microdensitometers and the algorithms of calculation inclusive the filter function and the accuracy of measurement of all project partners. 

McCormack D A, Kroes G J and Neuhauser D 1998 Resonance affected scattering Comparison of two hybrid methods involving filter diagonalization and the Lanczos method J. Chem. Phys. 109 5177... 

The Flat-bed pressure filter (Hydromation Engineering Co. Ltd.) (19) is based on the above principle. The pressure compartment consists of two halves, top and bottom. The bottom half is stationary while the top half can be raised to allow the belt and the cake to pass out of the compartment, and can be lowered onto the belt during the filtration and dewatering stage. The filter can be considered as a horizontal filter press with an indexing cloth in comparison with a conventional filter press, however, this filter allows only the lower face of the chamber to be used for filtration. 

Fig. 5. Effect of polymer dosage on different observed properties of flocculated slurry (40). Comparison of five parameters in a flocculation system (8%fluorite suspension + polyacrylamide Cyanamer P250). A, Rate of settling of floe boundary, in cm/s B, height of settled bed, cm C, height of consoHdated filter-cake, cm D, refiltration rate, arbitrary units and E, clarification, % optical transmission of 1 cm of supernatant Hquid after 3 min settling...

Fig. 27. Scanning electron micrograph (a) and cross-sectional comparison (b) of screen and depth filters both having a nominal particulate cut-off of 0.4 flm. The screen filter (a Nuclepore radiation track membrane) captures particulates at the surface. The phase-inversion ceUulosic membrane traps the...

Fig. 6. Comparison of xenon arc, sunshine carbon arc, and Miami average 45°S daylight, where (-) represents xenon with Type S high borate filters, 0.35...

Comparisons are available on the relative performance and costs for dewatering municipal sludges (2). The relative performance of different filters and conditioners on waste sludges is shown in Table 3. The same sludge was treated on two belt-filter presses, two different centrifuges, and rotary vacuum filter (75). In another study, a variable chamber filter press, fixed-volume filter press, continuous belt-filter press, and rotary vacuum filter were compared for performance, capacity, and capital and operating costs (69). 

Table 3. Comparison of Filters on Aerobically Digested Sludges ...

TABLE 17-11 Comparison of Air Filters by Percent Removal Efficiency for Various Particle Sizes ... 

Slurry Reactors with Mechanical Agitation The catalyst may be retained in the vessel or it may flow out with the fluid and be separated from the fluid downstream. In comparison with trickle beds, high heat transfer is feasible, and the residence time can be made veiy great. Pressure drop is due to sparger friction and hydrostatic head. Filtering cost is a major item. 

In this work hybrid method is suggested to determine cationic surfactants in water. It is based on preconcentration of cationic surfactants in the some of ion associates with acidic dyes on the paper filter and measurement of color intensity by solid-phase specdophotomenic method or visual comparison. 

Fig. 2.44. Chemical-bond mapping (a) comparison of EEL spectra recorded from matrix and SiC-fibre with the window for energy filtering shown (b) map of oxidic-bound Si.

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