| 摘要 |
<p>1,010,663. Heating air by exhaust gases. J. PRAT. May 4, 1962 [May 5, 1961], No. 17187/62. Headings F4K and F4S. The exhaust gases emerging intermittently from a converter or arc furnace are cooled to a temperature suitable for removing the dust therefrom in filters, e.g. cloth filters by connecting the outlet from the furnace to a heat exchanger 1 comprising vertical, straight fireresistant tubes 6 through which the exhaust gases are passed downwardly during a blowing period at a speed of more than 14 metres per sec., the heat exchanger being maintained in a condition to cool the exhaust gases to the required temperature by passing cooling air in the opposite direction to the exhaust gases. In Fig. 1, cooling air supplied by a blower 11 passes through a connecting pipe 13 into an annular chamber 13 whence slots 14 lead to a conduit of grate-like cross-section surrounding the tubes 6. The outlet from the latter conduit is through slots 17 into a further annular chamber 18 whence a connecting pipe 20 leads the heated air to a point of use. The heat exchanger is maintained at a uniform temperature by a thermostatically controlled valve 21. The exhaust gases are led off through a connecting pipe 9 to a cloth filter and dust collects in a bunker 7. In a modification valves are provided in the pipes leading the air and exhaust gases away from the heat exchanger and also in a further pipe connecting these pipes and the valves are controlled so that between blowing periods cooling air is passed upwardly through the tubes 6 by reversing a suction fan at the outlet of the connecting pipe 20. In Fig. 4 the dust bunker 7 has gates 28 and acts as a mixing chamber for exhaust gases which have passed down the tubes 6 and cooling air admitted at one side of the dust bunker. Between blowing periods valves 21, 27 at the bottom of the heat exchanger are controlled so that cooling air passes upwardly through the tubes 6 and out through a then open crest valve 30 to a point of use.</p> |
