초록 ▼

A method and apparatus are disclosed which reduce smoke emissions in an asphalt drum mixer. A drum mixer heats virgin aggregate to a relatively high temperature in a first drying zone. Virgin asphalt and, in some cases, recycled pavement material containing asphalt, are added in a second zone. Mixin

A method and apparatus are disclosed which reduce smoke emissions in an asphalt drum mixer. A drum mixer heats virgin aggregate to a relatively high temperature in a first drying zone. Virgin asphalt and, in some cases, recycled pavement material containing asphalt, are added in a second zone. Mixing and discharge of the materials occur in a third zone. The invention provides for air or water cooling of the gases in the drum mixer upstream of the point of entry of the asphalt. This cooling reduces the formation of smoke which would otherwise be generated by excessive heating of the asphalt. The apparatus, according to a preferred embodiment, employs an axially positioned air duct, the outlet end of which discharges cooling air into the drum just upstream of the area of entry of the recycled material.

대표청구항 ▼

A method of controlling smoke emissions from a drum mixer of the type having an inlet end and an outlet end and adapted for making paving material, such method comprising the steps of: (a) introducing aggregate into said drum adjacent the inlet end thereof; (b) heating said aggregate in a first heat

A method of controlling smoke emissions from a drum mixer of the type having an inlet end and an outlet end and adapted for making paving material, such method comprising the steps of: (a) introducing aggregate into said drum adjacent the inlet end thereof; (b) heating said aggregate in a first heating zone by a heating means located in the drum adjacent the inlet end thereof; (c) conveying said aggregate downstream from the inlet end of the drum to the outlet end thereof; (d) introducing asphaltic material into said drum at a second zone therein which adjoins the first zone downstream of the latter; (e) cooling the hot gases in the drum by controllably contacting such gases with a non-liquid cooling medium which is introduced in the drum in a substantially uniform pattern transversely thereof and in an area adjacent to and upstream of the second zone; (f) mixing the aggregate and the asphaltic material in the drum in a third mixing zone which adjoins the second zone downstream of the latter; and, (g) discharging the resulting mixture from the outlet end of the drum.