IMPROVEMENTS OF HEAT EXCHANGERS ASSOCIATED WITH STEEL SLAB FURNACES
A reheating furnace feeding a steel mill consumes 40,000 to 50,000 toe of fuel a year. This can be decreased by improving the efficiency of the heat exchangers which preheat combustion air using the exhaust gases of the furnace (at 1000 degrees C). The aim of the present work is to examine ways in which the existing heat exchangers can be improved by simple modifications which have a short pay-back time. The work carried out consists of simulating the heat exchanger with a computer model. This was based on experiments carried out on a 1/5 scale model and on measurements carried out in an industrial plant. Several construction improvements to the current heat exchangers have been identified, consisting of the introduction of metallic pieces which increase heat exchange, e.g. radiative panels increasing the radiative heat flux; and "turbulors", i.e. devices increasing the convective heat flux. Practical solutions are also proposed to avoid the errors of air preheater feed identified during the industrial trials. The proposed actions each lead to yearly energy savings calculated to be approximately 400 toe per furnace and are additive. Investment costs are moderate and give a pay back period of 6 months.
Bibliographic Reference: EUR 8859 FR (1984) MF, 42 P., BFR 120, BLOW-UP COPY BFR 210, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989123117200 / Last updated on: 1987-01-01
Available languages: fr