| 摘要 |
<p>When using high-speed burners, the time during which the burners are "on" is sometimes so short that the circulating hot gases do not have time to carry the heat equally to all parts of the charge. This situation is improved by reducing the temperature of the hot gases by admitting an excess of air up to a ratio of about 1.2. When the burner is switched "on", it works with excess air for a certain time before being switched back to the stoichiometric proportion. Then, when the burner is switched "off", it switches instead to working with excess air. It is thus possible to ensure even temperature for long periods, even when working with a partly loaded furnace.</p> |
