Heat exchangers tube inserts

Smooth high alloy tubes Low-finned tubes Sintered metal tubes Spiral heat exchanger Tube inserts Twisted tubes Helical tube support baffles... 

The term erosion-corrosion is used to describe the increased rate of attack caused by a combination of erosion and corrosion. If a fluid stream contains suspended particles, or where there is high velocity or turbulence, erosion will tend to remove the products of corrosion and any protective film, and the rate of attack will be markedly increased. If erosion is likely to occur, more resistant materials must be specified, or the material surface protected in some way. For example, plastics inserts are used to prevent erosion-corrosion at the inlet to heat-exchanger tubes. 

Heat exchanger tube leak moisture ingress, reactivity insertion... 

The heat transfer coefficient can be enhanced in the concentric tube heat exchanger by inserting a wire spacer or turbulator in the annular space as shown in Fig. 5.2c. The resulting increase in turbulence increases the Reynolds number, which in turn favorably affects the heat transfer coefficient. The heat transfer can be further improved by soldering the wire spacer to the outside surface of the inner pipe since this increases the effective heat-transfer area for the low-pressure side of the exchanger. 

The cod wound heat exchanger consists of multiple tubes heHcally wound on a mandrel, usually with spacers between each tube layer. The tubes are inserted into tube sheets at both ends of the tube bundle, with separate tube sheets to accommodate each tube circuit. The tube bundle is enclosed ia a sheU with inlet and outlet no22les for the sheUside fluid. This type of heat exchanger is usually constmcted of aluminum or stainless steel. Large aluminum... 

The tube-in-tube or multitube-in-tube heat exchangers are useful in small Linde lique-fiers or in the final Joule-Thomson stage of any liquefier. The performance of Linde-type exchangers is easy to calculate, and their realization is simple. In the examples shown in Fig. 5.12 (a)-(c), the tubes are concentric and the outer wall contributes appreciably to the pressure drop in the outer stream without contributing to the heat transfer. Usually, the smaller inner tube is used for the high-pressure stream and the low-pressure stream flows through the outer annular space. The tubes in Fig. 5.12 (d) and (e) are solder bonded while that in (f) is flattened and twisted before insertion into an outer tube. 

The generalization of such problems by introducing easily peneuable layers within the tube or duct, i.e. layers with disUibuted force (1.7), is oriented to a number of applications and brings also a light to main mechanisms associated with such flows. The applications include the water purification by porous inserts into pipelines, flows in vibrators, in journals and bearings with fibrous insets or brushes, in heat exchangers,... 

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