Heat exchanger for hot water system has a double bottom connected to the hot water primary circuit and with an enhanced heat transfer to destroy legionnaires bacteria

摘要

A heat exchanger for a hot water system free of legionnaires bacteria has an insulated tank (6) with a double bottom (1, 7) to form an inlet mixing chamber (4) for the hot water inlet (5) for the primary heating circuit. The inlet is via a shaped groove in the lower bottom for improved mixing. The primary circuit is ducted through a heat exchange spiral (2) to an outlet (13) near to the top of the heat exchanger. The secondary heating circuit has a lower inlet (9) and an upper outlet (10) in the tank. The flow pattern in the mixing chamber ensures that the bottom of the tank is sufficiently heated to kill the bacteria.