| 摘要 |
<p>Apparatus is disclosed for preparing a hot mix comprising aggregate and bitumen. The apparatus comprises a cylindrical vessel [16] incorporating a mixing chamber [42] provided with a rotating paddle assembly [SO] for mixing aggregate and bitumen loaded into the mixing chamber. The vessel also incorporates a heating chamber [44] located below, and separated from, the mixing chamber by a dome shaped separating element [46a, 46b], the centre of which is located at a higher level than its periphery. The heating chamber has a lower part [72] with a diameter that is less than that of its upper part [102]. A blower [93] is provided to force air into the lower part through a horizontally disposed passage [92] in which an oil [90] or gas burner is located for heating the air. The axis [X'] of the passage is offset from the vertical axis [X] of the heating chamber. The arrangement causes the heated air to spiral upwardly and outwardly [98] as it passes, first through the lower part [72] and then through the upper [102] of the heating chamber, traversing the separating element before exiting through apertures [56] disposed about the periphery of the separating element. The mix of aggregate and bitumen in the mixing chamber is heated by the heat transferred from the air as it passes over the separating element The rotary motion of the air is beneficial in distributing the heat uniformly over the separating element.</p> |
