Basket type evaporator

Basket Type Evaporators - the first basket - type evaporator was built in 1877 and an example of this type is shown in Figure 10. In this evaporator the liquid is inside the tubes, the steam is outside the tubes, but the downstage instead of being eentral is annular. In this eonstruetion the entire heating element is a single unit whieh may be removed bodily for repairs. The evaporator has a eonieal bottom, but flat bottoms are also eommon in this type. 

The tube proportions in the basket evaporator are about the same as in the standard vertieal. One important feature of the basket-type evaporator is the ease with which a deflector may be added in order to reduce entrainment from spouting. The boiling in the vertical-tube evaporator is quite violent, and this tends to cause entrainment losses. This condition is accentuated if the liquor level in the evaporator is low. A baffle such as shown in Figure 9 largely prevents these losses and is much more easily added to the basket type than to the standard type. Other differences between the standard and the basket type are largely details of construction. 

The mixture of two liquid phases is cooled in water cooler E-103 and then separated in brine decanter V-103. From that vessel the lighter phenol phase proceeds (P-108) to a basket type evaporator D-101 that is heated with steam. Overhead vapor from... 

In the basket type evaporator (Figure 11-8), construction and operation is much the same as a standard evaporator except that the downcomer is annular. This construction often is more economical and permits the evaporator to be removed for cleaning and repair. An important feature is the easily installed... 

Figure 11>8 Crosseectlonal diagram of basket-type evaporator. (Swenson Evaporator Co.)...

Vertical-type natural circulation evaporator. In this type of evaporator, vertical rather than horizontal tubes are used, and the liquid is inside the tubes and the steam condenses outside the tubes. Because of boiling and decreases in density, the liquid rises in the tubes by natural circulation as shown in Fig. 8.2-lb and flows downward through a large central open space or downcomer. This natural circulation increases the heat-transfer coefficient. It is not used with viscous liquids. This type is often called the short-tube evaporator. A variation of this is the basket type, where vertical tubes are used, but the heating element is held suspended in the body so there is an annular open space as the downcomer. The basket type differs from the vertical natural circulation evaporator, which has a central instead of annular open space as the downcomer. This type is widely used in the sugar, salt, and caustic soda industries. 

The continuous centrifuge is fed with salt slurry from the evaporators. Figure 5 shows the main components and operating principles for this type of unit. The salt slurry from the evaporators is continuously fed from the top inlet where it falls between the helicoidal blades of the extractor and the conical basket. The basket... 

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