Pressure tube side, heat exchanger

Equipment Failure pumps, tubes in heat exchangers and furnaces, turbine drivers and governor, compressor cylinder valves are examples of equipment which might fail and cause overpressure in the process. If an exchanger tube splits or develops a leak, high pressure fluid will enter the low side, overpressuring either the shell or the channels and associated system as the case may be. 

Pressure drop in heat exchangers Tube-side... 

Process (12). The reactor is a horizontal pressure vessel called Contactor and containing an inner circulation tube, a heat exchanger tube bundle to remove the heat of reaction, and a mixing impeller in one end. The hydrocarbon feed and recycle acid enter on the suction side of the impeller inside the circulation tube. This design ensures the formation of a fine acid-continuous emulsion. The high circulation rate prevents significant temperature differences within the reactor. The reactor is shown schematically in Fig. 11. 

Neeraas, B.O. Condensation of hydrocarbon mixtures in coil-wound LNG heat exchangers, tube-side heat transfer and pressure drop , Dr.ing. thesis, NTH, 1993... 

Ammonia Vaporizer A shell and tube-type heat exchanger with two passes per shell on the tube side. This unit should contain internal baffles. Operating pressure is 1240 kPa, with a design pressure of approximately 1400 kPa. This exchanger is made from mild steel. 

The simplest unit employing vacuum fractionation is that designed by Canadian Badger for Dominion Tar and Chemical Company (now Rttgers VFT Inc.) at Hamilton, Ontario (13). In this plant, the tar is dehydrated in the usual manner by heat exchange and injection into a dehydrator. The dry tar is then heated under pressure in an oil-fired hehcal-tube heater and injected directly into the vacuum fractionating column from which a benzole fraction, overhead fraction, various oil fractions as side streams, and a pitch base product are taken. Some alterations were made to the plant in 1991, which allows some pitch properties to be controlled because pitch is the only product the distillate oils are used as fuel. 

For an all-steel heat exchanger AAith mixed design pressures the total extra for pressure is 0.7 X pressure extra on shell side plus 0.3 X pressure extra tube side. 

The shape of the coohng and warming curves in coiled-tube heat exchangers is affected by the pressure drop in both the tube and shell-sides of the heat exchanger. This is particularly important for two-phase flows of multicomponent systems. For example, an increase in pressure drop on the shellside causes boiling to occur at a higher temperature, while an increase in pressure drop on the tubeside will cause condensation to occur at a lower temperature. The net result is both a decrease in the effective temperature difference between the two streams and a requirement for additional heat transfer area to compensate for these losses. 

Damage will be confined to the bubble-collapse region, usually immediately downstream of the low-pressure zone. Components exposed to high velocity or turbulent flow, such as pump impellers and valves, are subject. The suction side of pumps (Case History 12.3) and the discharge side of regulating valves (Fig. 12.6 and Case History 12.4) are frequently affected. Tube ends, tube sheets, and shell outlets in heat exchanger equipment have been affected, as have cylinder liners in diesel engines (Case History 12.1). 

Common to all air cooled heat exchangers is the tube, through which the process fluid flows. To compensate for the poor heat transfer properties of air, which flows across the outside of the tube, and to reduce the overall dimensions of the heat exchanger, external fins are added to the outside of the tube. A wide variety of finned tube types are available for use in air cooled exchangers. These vary in geometry, materials, and methods of construction, which affect both air side thermal performance and air side pressure drop. In addition, particular... 

There are many text books that describe the fundamental heat transfer relationships, but few discuss the complicated shell side characteristics. On the shell side of a shell and tube heat exchanger, the fluid flows across the outside of the tubes in complex patterns. Baffles are utilized to direct the fluid through the tube bundle and are designed and strategically placed to optimize heat transfer and minimize pressure drop. 

The shell and tube sides of heat exchangers can be designed to contain the maximum attainable pressure on either side, eliminating reliance on pressure relief to protect the exchanger shell in case of tube rupture. 

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