Abstract:
A device for the preparation of coated products, particularly, but not exclusively, for the construction and maintenance of highways, from aggregate, finely divided material and a binder, comprising a cylindrical drum having an inlet end and an outlet end and rotatably mounted on a platform so that the inlet end is higher than the outlet end, a mechanism for feeding aggregate and finely divided material to the inlet end of the drum, a burner projecting into the inlet end of the drum, and a fixed chamber at the outlet end of the drum for receiving coated products and for discharge of gases circulating in the drum. The drum comprises three zones including a first zone which receives aggregate and finely divided material from the feeding means and conveys it to a second zone substantially without mixing, the second zone serving for homogenizing the mixture of aggregate and finely divided material and optionally for preheating and predrying the mixture and containing lifting devices for lifting the aggregate and finely divided material, the lifting capability of the devices increasing from the inlet to the outlet end of the second zone, and a third zone for mixing the aggregate and finely divided material mixture with binder and optionally for heating and drying the mixture, the binder being supplied to the inlet of the third zone. The third zone includes lifting devices having a high lifting capability such that the products form a substantially continuous curtain across the drum.
Abstract:
The device includes in a rotary cylindrical drum (1) a zone for transfer and heating (11) where the inner surface of the drum (1) is fitted with sections of blades (17) wound in a spiral across the drum (1). These blades (17) arranged projecting with respect to the inner surface of the drum (1), by their edges remote from the drum support baffleplates (18) in a longitudinal direction. The drum (1) likewise exhibits an isolation and drying zone (12) where the inner surface of the drum (1) is fitted with lifter devices (20-21) having a high retention capacity for lifting materials (25) up to the upper portion of the drum (1) and the formation by falling back of these materials (25) of a continuous screen isolating the flame (5) of the burner (4) from the next zone of the drum (1).