TABLE OF CONTENTS Condensers are used in a variety of operations in chemical and petroleum processing, including distillation, refrigeration, and power generation. Virtually, every distillation column employs either a partial or total condenser to liquefy some, or all, of the overhead vapor stream, thereby providing reflux for the column and (often) a liquid product stream. In refrigeration operations, condensers are used to liquefy the high-pressure refrigerant vapor leaving the compressor. Heat exchangers referred to as surface condensers are used to condense the exhaust from steam turbines that generate in-house power for plant operations.
Condensation is the reverse of boiling, and the condensing curve is the same as the boiling curve. Thus, many of the computational difficulties encountered in the analysis of reboilers are present in condensers as well. For wide-boiling mixtures, in particular, the nonlinearity of the condensing curve and the variation of liquid and vapor properties over the condensing range mean that a zone or incremental analysis is required for rigorous calculations. Mass-transfer effects may also be significant in the condensation of mixtures, as they are in nucleate boiling of mixtures.
On the other hand, condensing and boiling differ in important respects. In particular, condensation is more amenable to fundamental analysis, and useful heat-transfer correlations can be derived from first principles.
Most condensers used in the chemical process industries are shell-and-tube exchangers or air-cooled exchangers. In the latter, the condensing vapor flows inside a bank of finned tubes and ambient air blown across the tubes by...
