Baffles, types plate

For counterflow plates, the curves of Fig. 14-25 may be used for open areas of 20 percent or greater. Plates with 15 percent open areas have about 85 percent of the cui ve values, and open areas or less than 15 percent are not recommended. For counterflow-plate columns of the segmental-baffle type, 50 percent cut, allowable values are about 15 percent greater than tnose shown in Fig. 14-25, when vertical spacings of the baffles are equal to the trav spacings shown. 

There are many baffle type impingement separators. The efficiency of operation for entrainment is entirely a function of the contacting action inside the particular unit. There are no general performance equations which will predict performance for this type of unit therefore manufacturers performance data and recommendations should be used. A few of the many available units are shown in Figures 4-28 to 4-31. Many use the Chevron-style verdcal plates as shown in Figures 4-17A and 4-30. 

FIGURE 17.4 Plate baffle types (a) single-segmental baffle, (ft) double-segmental baffle, (c) triple-segmental baffle, (d) no-tubes-in-window segmental baffle, and (e) disc-and-doughnut baffle. 

Acccs. tor/cs Kiiockback coil, spiral baffle, entrainment plate, safety valve Materials of construction stainless steel, type 304... 

Baffles, distribution plates, and dry-type overspray collectors shall conform to OSHA standards. Overspray filters (where used) shall be installed and maintained in accordance with OSHA standards. 

The vane type mist eliminator consists of a series of baffles or plates, and the gas flows between them, as shown in Figure 3.3. The droplet that is impinged on the surface has a free fall downward. The space between the baffles varies from as low as 5 mm to 75 mm, and the depth in the direction of the flow varies from between 150 to 300 mm. 

A plate-type ESP is similar in principle to the tubular type except that the air flows across the wires horizontally, at right angles to them. The particles are collected on vertical plates, which usually have fins or baffles to strengthen them and prevent dust reentrainment. Figure 29-5 illustrates a large plate-type precipitator. These precipitators are usually used to control and collect dry dusts. 

Quench tower The type shown in Fig. 23-56, with a superimposed baffle plate section, is often used when complete condensation of the incoming vapors is not required. The exiting vapors are usually cooled to 150 to 200°F in the baffle plate section. This type is often used in petroleum refineries. 

When this type of impeller is used, typically four vertical baffle plates, each one-tenth of the tank diameter in width and the total liquid depth in length, are fixed perpendicular to the tank wall so as to prevent any circular flow of liquid and the formation of a concave vortex at the free liquid surface. 

A skim pile is a type of disposal pile. As shown in Fig. 9, flow through a scries of baffle plates creates quiescent wines that reduce the distance which a given oil droplet must rise to be separated from the main flow. Once in the quiescent zone, there is ample time for coalescence and gravity separation. Larger droplets then migrate up the underside of the baffle to an oil collection system... 

FIGURE 3 Sectional view of a typical fixed tubesheet shell-and-tube heat exchanger (A) tubes (B) tubesheets (C) shell (D) tube-side channel and nozzles (E) channel cover (F) pass divider plate (G) stationary rear head (bonnet type) (H) tube support plates (or baffles). 

In 1935, Van Dijck proposed that the extraction efficiency of a perforated-plate column could be improved by either pulsing the liquid contents of the column or by reciprocating the plates. The latter idea was relatively little exploited until the late 1950s, when Karr reported data on a 3-in.-diameter, open-type, perforated reciprocating-plate column. The column was further developed by Karr and Lo by employing baffles. 

The open-type perforated reciprocating-plate column (Fig. 13f) developed by Karr and Lo consists of a stack of perforated plates and baffle plates which have a free area of about 58%. The central shaft which supports the plates is reciprocated by means of a reciprocating drive mechanism located at the top of the column. These columns have gained increasing industrial application in the pharmaceutical, petrochemical, and wastewater-treatment industries, and columns up to 60 in. in diameter are in service. 

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