1981 Volume 7 Issue 1 Pages 13-18
Although submerged combustion apparatus has a very high thermal efficiency, the pressure drop is not small. To reduce this disadvantage, a heat exchanger with direct contact of combustion gas and liquid using dual flow has been developed. It was found to be possible to maintain a very high thermal efficiency, even if the pressure drop was suppressed to less than 1/10 of the usual value. The thermal efficiency was dependent not on hole diameter, but on the ratio of total hole area to column area on the perforated plate. A heat transfer model without mass transfer was devised to obtain an empirical equation for the volumetric heat transfer coefficient, and this model was compared with heat-and-mass transfer model. In this system, condensation occurred in the range of low liquid temperature. The effect of condensation may be ignored due to the small amount of condensation.
