| 摘要 |
<p>The heating system is installed in an oil- or gas-fire flue in order to improve the efficiency. One or more heater coils (3) are mounted in the outlet (1) from a boiler, or in the flue itself (2), water flowing through them with or without the aid of a pump (7). The coils can be cylindrical or tapering, mounted one inside the other and also in a row one after the other. Their union nipples (4) can be welded, soldered, hard-soldered or clamped into place, in bores in the flue or the boiler outlet, and have screw-threads for pipe connections.</p> |
