Collection efficiency experimental

For smaller particles, the theory indicates that efficiency decreases according to the dotted line of Figure 7. Experimental data (134) (sofld line of Eig. 7) for a cyclone of Eig. 9 dimensions show that equation 15 tends to overstate collection efficiency for moderately coarse particles and understate efficiency for the finer fraction. The concept of particle cut-size, defined as the size of particle collected with 50% mass efficiency, determined by equation 16 has been proposed (134). 

FIG. 14-115 Experimental collection efficiencies of rectangular impactors. C is the Stokes-Ciinningbam correction factor Pp, particle density, g/ond U, superficial gas velocity, approaching the impactor openings, cm/s and ig, gas viscosity, P. Calveri, Yung, and Leung, NTIS Puhl. PB-24S050 based on Mercer and Chow, J. Coll. Interface Sci., 27, 75 (1.96S).]... 

FIG. 14-117 Experimental collection efficiency. Vs-in Intalox saddles. To convert feet per second to meters per second, multiply by 0.3048 to convert centimeters to inches, multiply by 0.394 and to convert grams per cubic centimeter to pounds per cubic foot, multiply by 62.43. [Jackson and Calvett, Am. Inst. Cbem. Eng. J., 12,1975 (1968).]... 

A series of theoretical analyses of the fluid and particle collection efficiency of cyclones were performed in the 1970s by Bloor and Ingham " and they have been found to be in good agreement with the experimental data. 

The above predictions will now be compared with the experimental results. The high probability volume agrees well with the movable slit observations above. The predicted low collection efficiency for electrons is also observed. Figure 5 (bottom) shows the ratio of negative to positive ion current collected on the blanked-off conical electrode for different gases. For the rare gases this ratio is small especially at low pressures while... 

For the separation of gas-solid mixtures, preliminary design of inertial separators, cyclones, electrostatic precipitators, scrubbers and some types of filters can be carried out on the basis of collection efficiency curves derived from experimental performance. 

Because variables in models are often highly correlated, when experimental data are collected, the xrx matrix in Equation 2.9 can be badly conditioned (see Appendix A), and thus the estimates of the values of the coefficients in a model can have considerable associated uncertainty. The method of factorial experimental design forces the data to be orthogonal and avoids this problem. This method allows you to determine the relative importance of each input variable and thus to develop a parsimonious model, one that includes only the most important variables and effects. Factorial experiments also represent efficient experimentation. You systematically plan and conduct experiments in which all of the variables are changed simultaneously rather than one at a time, thus reducing the number of experiments needed. 

The various venturi-scrubber models embody a variety of assumptions and approximations. The solutions of the equations for particulate collection must in general be determined numerically, although Calvert et al. [J. Air Pottut. Control Assoc., 22, 529 (1972)] obtained an explicit equation by making some simplifying assumptions and incorporating an empirical constant that must be evaluated experimentally the constant may absorb some of the deficiencies in the model. Although other models avoid direct incorporation of empirical constants, use of empirical relationships is necessary to obtain specific estimates of scrubber collection efficiency. One of the areas of greatest uncertainty is the estimation of droplet size. 

Data Treatment. The experimental design of sample collection did not permit statistical comparison of the collection efficiencies of filter combinations versus concentrated HNO3 impingement. The laboratory chamber was designed to simulate field conditions and not provide a "closed" system in which the concentrations of Plictran could be controlled. 

The experimental collection efficiencies for H202 (estimated Graham s law diffusion coefficient is 0.18 cm2/s) for an aqueous scrubber Nafion (per-fluorinated ionomer) membrane DS (L = 40 cm, d0 = 0.5 cm, and d = 0.06 cm) have been experimentally determined by two independent ap-... 

The efficient sink criteria cannot be overemphasized, however. When the experimental data for formaldehyde for either of the two different membrane scrubbers are considered, the theoretical predictions significantly exceed the experimental collection efficiencies. The uptake of formaldehyde at an aqueous interface is controlled by its rate of hydration to methylene glycol, a process that is acid- or base-catalyzed. The collection efficiency significantly increases in going from pure water to 0.1 M H2S04 as a scrubber liquid (55), but the uptake probability still remains a controlling factor in determining the collection efficiency. Obviously, in such cases theoretical predictions merely establish an upper limit. 

Experimental work has been published on a ring—disc electrode which is intermediate in geometry between the wall-jet and wall-tube configurations. Consequently, and as expected, intermediate collection efficiency values were measured [51]. 

N being the collection efficiency of the RRDE. For the latter, the theoretical value was used, as it follows from the characteristic dimensions of the RRDE. In one case (nGaP/Fe(CN) ) where, from independent measurements, the conditions are known under which s = 1, we were able to check that the experimental N value is in good agreement with the calculated one. 

Figure 3. Experimental collection efficiency vs. wavelength with fit to data using Gartner model (measured values of t and N, and L = 1 pm were used to fit data)...

When fibers are packed together in a filter bed, the velocity will be increased and the flow pattern will be changed, which increases the collection efficiency from impaction and interception. Chen (1955) has determined fiber interference effects experimentally and suggests... 

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