Heat Exchanger Tube Plates

The tube-plates (tube-sheets) in shell and tube heat exchangers support the tubes, and separate the shell and tube side fluids (see Chapter 12). One side is subject to the shell-side pressure and the other the tube-side pressure. The plates must be designed to support the maximum differential pressure that is likely to occur. Radial and tangential bending stresses will be induced in the plate by the pressure load and, for fixed-head exchangers, by the load due to the differential expansion of the shell and tubes. 

The ligament is the material between the holes (that which holds the holes together). In a tube-plate the presence of the tubes strengthens the plate, and this is taken into account when calculating the ligament efficiency by using the inside diameter of the tubes in place of the hole diameter in equation 13.111. 

Design procedures for tube-plates are given in BS PD 5500, and in the TEMA heat exchanger standards (see Chapter 12). The tube-plate must be thick enough to resist the bending and shear stresses caused by the pressure load and any differential expansion of the shell and tubes. The minimum plate thickness to resist bending can be estimated using an equation of similar form to that for plate end closures (Section 13.5.3). 

The value of the design factor Cpi, will depend on the type of head, the edge support (clamped or simply supported), the plate dimensions, and the elastic constants for the plate and tube material. 

The tube-sheet design pressure AP depends on the type of exchanger. For an exchanger with confined heads or U-tubes it is taken as the maximum difference between the shell-side and tube-side operating pressures with due consideration being given to the possible loss of pressure on either side. For exchangers with unconfined heads (plates fixed to the shell) the load on the tube-sheets due to differential expansion of the shell and tubes must be added to that due to the differential pressure. 

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Use Condenser, evaporator, and heat exchanger tubes, plates, and ferrules. 

Normally, heat exchanger tubes are arranged in a staggered manner. The continuous plate is considered as being built up of regular hexagons, with a hole in the center for the pipes. This arrangement is shown in Fig. 9.9. 

Heat exchanger tube expanded into tube plate... 

Any of various types of heat transfer equipment, whereby relatively cold water flowing over a surface will, by conduction and convection means, transfer heat away from a process. The most common types of heat exchangers are plate and frame and shell and tube designs. A boiler is also a type of heat exchanger. 

Internals. Commercial fluidized beds are often equipped with internals, eg., baffle plates and heat exchanger tubes. Due to their interaction with the rising bubbles they will certainly cause particle attrition. Unfortunately, no systematic investigations are available in the open literature which could serve as practical guidelines. 

Note that it is okay to heat softened or demineralized water to 160°F. You should not, however, do this with raw water. Calcium carbonate salts will plate out and foul the heat-exchanger tubes. 

Diameter of the ports in the plates of a plate heat exchanger Tube outside diameter... 

When the heat exchanger tubes are oriented vertically, the bubbles produced by boiling rise and carry liquid with them. Tubes are typically 1 or 2 inches in diameter and 12 to 32 feet in length. The liquid entrained in the vapor coming out of the HX is richer in solute than that entering the HX. Vapor and fine liquid droplets are separated in the vapor head by placing a baffle plate in the path of the two-phase fluid coming out of the HXer. 

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