초록 ▼

A drum mixer is useful in the continuous production of asphalt paving composition, and has provision for the accurate control of the final temperature of the composition being produced. The drum mixer comprises a fixedly mounted cylindrical sleeve disposed in a generally horizontal orientation, and

A drum mixer is useful in the continuous production of asphalt paving composition, and has provision for the accurate control of the final temperature of the composition being produced. The drum mixer comprises a fixedly mounted cylindrical sleeve disposed in a generally horizontal orientation, and rotating blades for conveying the heated aggregate longitudinally through the interior of the sleeve. An opening is provided in the side wall portion of the sleeve, and a box-like enclosure covers the opening and mounts a plurality of sensor mounting tubes, so as to permit one or more sensors to be positioned at a location within the enclosure. The enclosure is located where the blades or mixing action in the sleeve will supply a regular flow of the aggregate into the enclosure, and so that the aggregate then slides over the sensors. The sensors are thus subjected to a representative portion of the aggregate, and they are protected from both the radiant heat of the burner and the physical abuse of the mixing action.

대표청구항 ▼

1. A drum mixer adapted for heating and drying an aggregate, and comprising a fixedly mounted cylindrical sleeve disposed in a generally horizontal orientation and defining opposite side wall portions, means for conveying heated aggregate longitudinally through the interior of said sleeve, and

1. A drum mixer adapted for heating and drying an aggregate, and comprising a fixedly mounted cylindrical sleeve disposed in a generally horizontal orientation and defining opposite side wall portions, means for conveying heated aggregate longitudinally through the interior of said sleeve, and means for sensing the temperature of the heated aggregate as it is conveyed through the interior of said sleeve, said sensing means comprising (a) an opening in one of said side wall portions of said sleeve, (b) a box-like enclosure mounted on the outside of said sleeve so as to cover said opening, with said enclosure including an outer wall, a top wall, and opposite side walls, and with said outer wall disposed generally along a tangent to said one side wall portion of said sleeve when viewed in vertical cross section and so that a portion of the heated aggregate which is being conveyed through said sleeve is adapted to be conveyed into said enclosure through said opening and then fall by gravity along said outer wall and back through said opening and into the interior of said sleeve, (c) a temperature sensor for sensing the temperature of the aggregate which is conveyed into and then falls from said enclosure, and (d) sensor mounting means for mounting said temperature sensor within said enclosure. 2. The drum mixer as defined in claim 1 wherein said sensor mounting means comprises at least one mounting tube extending through one of said walls of said enclosure so as to permit said temperature sensor to extend through said tube and into said enclosure. 3. The drum mixer as defined in claim 1 further comprising means for heating said aggregate and means for delivering said aggregate into the interior of said sleeve. 4. The drum mixer as defined in claim 3 further comprising means for controlling said heating means in response to the temperature sensed by said sensor to permit the temperature of the aggregate to be closely controlled. 5. The drum mixer as defined in claim 4 further comprising means for introducing liquid asphalt into the interior of said sleeve at a location downstream of said opening and so that the liquid asphalt is mixed with the heated aggregate being conveyed therethrough. 6. A drum mixer useful in the continuous production of asphalt paving composition, and comprising an elongate hollow drum defining a central axis, means mounting said drum for rotation about said central axis and with said central axis being inclined with respect to the horizontal so as to define an upper end and a lower end of said drum, aggregate inlet means positioned adjacent said upper end of said drum for introducing aggregate into the interior of said drum, aggregate outlet means positioned adjacent said lower end of said drum for withdrawing aggregate from the interior of said drum, means for rotating said drum about said central axis so as to cause the aggregate which is introduced at said inlet means to cascade through the interior of said drum and move to said outlet means, heating means positioned adjacent said lower end of said drum for introducing heated gas into the interior of said drum, exhaust duct means positioned adjacent said upper end of said drum for exhausting the heated gas therefrom and so that the heated gas flows through said drum and through the cascading aggregate, a fixed sleeve mounted coaxially about a portion of the length of said drum adjacent said lower end thereof and so as to define an annular chamber between said drum and said sleeve, said sleeve having a lower end overlying said outlet means of said drum and an upper end positioned intermediate said ends of said drum with said outlet means of said drum opening into said annular chamber so as to receive the heated and dried aggregate therein, and with said sleeve further including opposite side wall portions and a discharge opening adjacent said upper end thereof, mixing vane means mounted to the exterior of said drum so as to be positioned within said annular chamber for mixing the aggregate received therein upon rotation of said drum and moving the aggregate toward said discharge opening of said sleeve, means for sensing the temperature of the heated aggregate as it is conveyed through said annular chamber, said sensing means comprising (a) an opening in one of said side wall portions of said sleeve, (b) a box-like enclosure mounted on the outside of said sleeve so as to cover said opening, with said enclosure including an outer wall, a top wall, and opposite side walls, and with said outer wall disposed generally along a tangent to said one side wall portion of said sleeve when viewed in vertical cross section and so that a portion of the heated aggregate which is being conveyed through said annular chamber is adapted to be conveyed into said enclosure through said opening and then fall by gravity along said outer wall and back through said opening and into the interior of said annular chamber, (c) a temperature sensor for sensing the temperature of the aggregate which is conveyed into and then falls from said enclosure, and (d) sensor mounting means for mounting said temperature sensor within said enclosure. 7. The drum mixer as defined in claim 6 further comprising means for controlling said heating means in response to the temperature sensed by said sensor to permit the temperature of the aggregate to be closely controlled. 8. The drum mixer as defined in claim 7 further comprising means for introducing liquid asphalt into said annular chamber at a location downstream of said opening and so that the liquid asphalt is mixed with the heated aggregate being conveyed therethrough. 9. The drum mixer as defined in claim 8 further comprising means positioned adjacent said lower end of said sleeve for introducing an additive into said annular chamber so as to be mixed with the aggregate and the liquid asphalt therein. 10. The drum mixer as defined in claim 8 wherein said top wall of said enclosure is hingedly mounted to said sleeve to facilitate access to the interior of the enclosure. 11. The drum mixer as defined in claim 8 wherein said sensor mounting means includes a plurality of sensor mounting tubes which extend through one of said walls of said enclosure to permit a plurality of said temperature sensors to be positioned in said enclosure. 12. The drum mixer as defined in claim 8 wherein said top wall of said enclosure lies in a plane which includes said central axis, and said opposite side walls of said enclosure lie in parallel planes which are each inclined at an angle of about 60 degrees from said central axis when viewed in side elevation.