Heat exchange equipment

Impervious graphite heat-exchanger equipment is made in a variety of forms, including outside-packed-head shell-and-tube exchangers. They are fabricated with impervious graphite tubes and... 

Installation of heat-exchange equipment to precool and dehumidify the feed gas to an absorber also deserves consideration in order to take advantage of the cooling effects created by vaporization of solvent in the lower sections of the tower. 

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). 

Hardness Calcium, magnesium, barium and strontium salts expressed as CaCOa Chief source of scale in heat exchange equipment, boilers, pipe lines, etc. forms curds with soap interferes wKh dyeing, etc. Softening, distillation, internal boiler water treatment, surface active agents, reverse osmosis, electrodialysis... 

Oxygen O2 Corrosion of water lines, heat exchange equipment, boilers, return lines, etc. Deaeration, sodium sulflte, corrosion inhibitors, hydrazine or suitable substitutes... 

Suspended Solids None Suspended Solids is the measure of undissolved matter, determined gravimetrically suspended solids plug lines, cause deposits in heat exchange equipment, boilers, etc. Subsidence, filtration, usually preceded by coagulation and settling... 

Effects of Water Hammer. Water hammer has a tremendous and dangerous force that can collapse floats and thermostatic elements, overstress gauges, bend mechanisms, crack trap bodies, rupture fittings and heat exchange equipment, and even expand piping. Over a period of time, this repeated stress on the pipe will weaken it to the point of rupture. 

Water hammer can also occur in steam mains, condensate return lines, and heat exchange equipment where steam entrapment can take place (Fig. I). A coil constructed and installed as shown here, except with just a steam trap at the outlet, permits steam from the control valve to be directed through the center tube(s) first. Steam then gets into the return header before the top and bottom tubes are filled with steam. Consequently, these top and bottom tubes are fed with steam from both ends. Waves of condensate are moved toward each other from both ends, and steam can be trapped between the waves. 

Damaging water hammer similar to that Just described is experienced also when elevated heat exchange equipment is drained with a long vertical drop to a trap. 

These historical and fundamental concepts form the foundation for the design, applications, and operations of a major class of equipment that are used throughout the chemical process industries - heat exchange equipment, or heat exchangers. There are many variations of these equipment and a multitude, of... 

Singh, K. P. and K. K. Niyogi - editors, Heat Exchange Equipment and Valve Design and Operability Improvement, International Joint Power Generation Conference, Pheonix, AZ, 1994. 

Hardness Calcium and magnesium salts in the forms of CaCOj, Ca, Mg. This is the primary source of scaling in heat exchange equipment, boilers, pipelines/transfer lines, etc. Tends to form curds with soap and interferes with dyeing applications as well. 

The process engineer identifies heat exchange equipment in a process by the operation or function it serves at a particular location in the flow cycle. For example, the bottom vaporizer on a product finishing distillation column is usually termed Finishing Column ReboUer E-16, or Reboiler E-16 the overhead vapor condenser on this column is termed Condenser E-17 etc. The usual operations involved in developing a process flowsheet are described in Table 10-11, or Chapter 1, Volume 1. 

In condensers where heat loss is desired, insulation often is omitted from piping carrying hot fluids to take advantage of the heat loss to the atmosphere. In any heat exchange equipment the heat released or lost by one fluid must be accounted for in an equivalent gain by a second fluid, provided that heat losses are negligible or otherwise considered. 

In most process systems, the evaporation of the refrigerant is carried out in shell and tube heat exchange equipment, and allowance must he made for a reasonable temperature approach between the process fluid and the evaporating refrigerant. The process fluid always leaves the evaporator at a higher temperature (by 3°-15°F) than the refrigerant. 

Prepare inquiry specifications for compressors and heat exchange equipment following the forms suggested. 

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