Flood load

Refer to Flooding, Loading and Pressure Drop Chart, Figure 9-21D. 

Operating load as percentage of maximum flood load... 

Figure 9-49. Estimated pressure drop referenced to percentage of maximum flood load for structured woven/knitted wire mesh X-100 and S-100. Referenced to liquid of 60 Ib/ft. To correct other liquids, multiply AP from figure by ratio of actual liquid density to 60. Used by permission of ACS Industries, Inc., Separation Technology Division, Bull. 8-129(1992).

Salles C, Toumoud MG, Chu Y (2008) Estimating nutrient and sediment flood loads in a small Mediterranean river. Hydrol Process 22(2) 242-253... 

Adjust the downcomer flood approximately equal to the tray active area flood. With these two flood values equal or nearly equal, the tray is considered to have a balance of loading between the downcomer loading and the active tray area loading. This balance ensures that the tray will operate efficiently even if it has less than 50% flood loadings. Review these two flood values (downcomer and active area flood values) carefully and make adjustments, especially in new tray design, ensuring that these flood values are close to equal. 

Since both flood numbers are equal, no selection is necessary. Normally you should select the greater flood loading for the controlling number. 

Both are close loadings with the raffinate phase slightly larger. This is mainly due to the fact that the continuous phase floods at a lower Vc. The flood numbers are truly too close to call for any significant difference. Thus a diameter of 2.25 ft is required for the desired 80% flood loading. 

Membrane contactors are membrane systems usually based on microporous membranes that keep two phases in contact. The presence of the membrane and the right choice of the operating pressures avoid the mixing of the phases. This implies that the flow rates of the phases can be varied independently over a wide range without any problem of flooding, loading, channeling. 

The transfer step may also be conducted via gravity transfer via a single or bifurcated chute (Fig. 2), depending on the press configuration. Since these chutes are often operated in a flood-loaded manner (full cross section) and may consist of converging sections where the cross-sectional area of the chute is reduced, they often need to be designed for reliable flow in a similar manner as the IBCs. 

Once the final blend has been transferred to the press hopper reliably, it is important to ensure that press hopper also provides reliable flow. Most modem presses consist of a small press hopper that is, in essence, a miniature IBC designed to provide a small amount of surge capacity. The press hopper often consists of a cylinder section and a hopper section similar to a larger IBC, but the hopper section may be asymmetric (Fig. 3) as opposed to the symmetric hopper designs commonly used for IBCs. The press hopper is typically flood-loaded from the IBC/chute above via gravity feed. However, in some instances, the material level in the press hopper may be controlled via a feeder at the IBC... 

For converging sections that are flood loaded and have a full cross section (i.e., hoppers), use the same design criteria used for mass flow bins discussed above. 

A conservative design would be to take 90% of the Glitsch value as the flooding load with Sin. bubble caps, and 70% of the valve-tray flooding load for a tray wifh 6 in. caps (Fractionation Research, Tulsa, Oklahoma, U.S.A., private communication). 

Figure 15.14 Power curves at constant gas rate for Rushton turbines for the flooding-loading transition. With ring spargers,...

Ncd agitator speed to just completely disperse the gas (rev s ) flooding-loading transition speed (revs ) agitator speed at which gross recirculation starts (rev s ) Nusselt number (hD/k) pressure (N/m )... 

Packing Nominal fliza, in Characteristics Flood Load... 

Nienow, A.W., Warmoeskerken, M.M.C.G., Smith, J.M., and Konno, M. (1985), On the flooding/loading transition and the complete dispersal condition in aerated vessels agitated by a Rushton-turbine, in Fifth European Conference on Mixing, Wuerzburg, West Germany, BHRA, Cranfield, England 143-154. 

For the design (Sauter diameter, droplet velocity, pressure profile, residence time distribution, flooding load, etc.) see [6.71, 6.73-6.75]. Extractor selection and operating parameters have to be determined exper-... 

An air-assisted discharger is designed to aerate only a thin layer of bulk solid above the permeable membrane. For such a system to work properly the air must be able to easily exit the bin through its outlet when solids are discharged. This usually means that discharge cannot be restrained, such as is the case with a flood-loaded feeder. Instead, a full port ball or dome valve is used to discharge slugs of bulk solid from the bin. 

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