Walk, Haydel Approach to Process Heat Recovery

Abstract

Walk, Haydel has developed a two phase approach to optimize the recovery of process heat in energy intensive operations. While the approach can be used on 'grassroots' designs, it has been used primarily for revamps. The capital investment for adding heat exchange to processes economically justified when energy cost were low, is paid back in less than 3 years before taxes. Computer models of process operation are first used to improve process efficiencies and to increase the level of available process heat. Using in-house computer software based on the Nishida, Liu and Lapidus approach (AICHE Journal, 1977, Vol. 23, No.1); Walk, Haydel develops the theoretical optimum heat exchanger train arrangement for the process. Existing exchangers are reused and integrated into a practical design based on the theoretical arrangement. This paper will discuss briefly the Walk, Haydel procedure and will provide an example problem to demonstrate its use. Then, case histories will be reviewed to indicate the potential for heat recovery in a variety of processing units.