| 摘要 |
<p>A hot water cylinder (10) having upper and lower horizontally extending immersion heaters (13, 12) is provided with a pair of spaced parallel upright baffle plates (14) positioned one on each side of the lower heating element (12) to cause a column of heated water to rise centrally within the cylinder (10) and to circulate downwardly outside the baffles thus to create substantially complete circulation by convection of heated water within at least the lower part of the cylinder to ensure a substantially uniform water temperature therein. In an alternative arrangement of a helical upright heating coil (23) the baffle plate is formed as a cylindrical sleeve (24) within the coil such that heated water rises outside the sleeve (24) and circulates downwardly inside the latter. The provision of the baffle avoids the creation of pockets of cooler water in the base of the cylinder (10) in which bacteria may breed.</p> |
