| 摘要 |
<p>The open fireplace structure comprises a hearth, a cowl and a smoke tube connected to the chimney. The hearth (2) and cowl (3) have double walls which are impermeable to water, being pref. of metal. The totally-enclosed chamber (4) formed by the walls has water supply and return unions (5, 6), these being connected by pipes to a central-heating system etc. The supply union can be at the top of the cowl and the return one at the bottom of the hearth. The fireplace is designed to give a comparatively high heating efficiency.</p> |
