Separator mist eliminator

Figure 4-17A. Separation/Impingement action of Chevron-style mist eliminators. Flow Is up the V-shaped plates assembly. Courtesy of Bulletin KME - 12, Koch Engineering Co.

Figure 4-27B. Fiber-pack mist eliminator pack separators. By permission, Koch Engineering Co., Inc. Note that other manufacturers have basically the same concept however, the identification of types are peculiar to each.

The four stage exhaust box Includes the oil box separator, the demister pad, the oil mist eliminator, and the synthetic oil baffle. Additional features include ein automotive type spin-on oil filter, a built-in inlet anti-suckback valve that prevents oil from being drawn into the system when the pump is stopped, eind a built-in gas ballast, available on the RA version, which permits pumping with high water vapor loads. 

After the throat section, the mixture decelerates, and further impacts occur causing the droplets to agglomerate. Once the particles have been captured by the liquid, the wetted PM and excess liquid droplets are separated from the gas stream by an entrainment section, which usually consists of a cyclonic separator or a mist eliminator. 

Centrifugal mist eliminators separate liquid dropi by centrifugal force. These can be more efficient than either wire mesh or mist eliminators, and are the least susceptible to plugging. However, they are not in common use in production operations because removal efficiencies are sensitive to small changes in flow. In addition, they require relatively large pressure drops to create the centrifugal force. 

Drop Size. The purpose of the vessel s gas separation section is to condition gas for final polishing by the mist eliminator. From field experience, it appears that if 100-micron drops are removed in this section, the mist eliminator will not become flooded and will be able to remove those drops between 10 and 100-micron diameter. 

As shown in Fig. 11, allowance must be made for the gas separation section, mist eliminator and for any space below the liquid outlet. For screening purposes the following approximation has been proven useful ... 

Follow the procedure outlined in Table 6.10. Assume that a vertical separator with a mist eliminator will be used. From Equation 6.9.3, ky = 0.35 ft/s (0.107 m/s). 

Let us try to reduce the size of the horizontal separator. If we move the mist eliminator to outside of the separator shell, as shown in Figure 6.3.1, the diameter... 

Figure 6.3.1 A horizontal gas-liquid separator with an external mist eliminator. 

The vertical separator is 1.625 ft (0.494 m) in diameter and 8.5 ft (2.59 m) long. At this point, it appears that the vertical separator is the best choice because of its smaller diameter and wall thickness. Also, locating the mist eliminator outside of the separator shell will add to the cost of the horizontal separator. 

Entrainment separators, or catchalls , and mist eliminator pads can be installed where the vapor is removed from the vessel by the vacuum system the recovered product can be returned to the process at an appropriate point. 

The tower absorber section is separated from the cyclonic mist eliminator by a plate containing a conical hat. This arrangement allows the flue gas to leave the cyclonic mist eliminator but prevents the slurry leaving the packed absorption tower from combining with the slurry stream leaving the FDS. Hence, most of the fly ash entering the system is isolated from the absorption tower and is conflned to the FDS slurry stream. 

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