# US 5,344,229 A · Angle and velocity adjustment of a hot mix asphalt drum when output gas temperatures are uneven

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- Number: US 5,344,229 A
- Document ID: US5344229A
- Status: Granted
- Kind: A
- Application number: 07/949,564
- Filed: 1992-09-23
- Granted: 1994-09-06
- Earliest claimed: 1989-07-31
- Assignees: Cyclean, Inc.
- Inventors: Robert H. Nath; John Wiley; Robert Erickson; Carl R. Hutchison; Mike Miles
- Web page: https://patentgrep.com/patent/US5344229A

## CPC

- E01C 19/1004: {Reconditioning or reprocessing bituminous mixtures, e.g. salvaged paving, fresh patching mixtures grown unserviceable; Recycling salvaged bituminous mixtures; Apparatus for the in-plant recycling thereof (E01C19/1036 takes precedence)}
- E01C 19/1036: {for in-plant recycling or for reprocessing, e.g. adapted to receive and reprocess an addition of salvaged material, adapted to reheat and remix cooled-down batches}
- E01C 19/1063: {Controlling the operations (E01C19/1068 takes precedence)}
- F26B 11/028: {Arrangements for the supply or exhaust of gaseous drying medium for direct heat transfer, e.g. perforated tubes, annular passages, burner arrangements, dust separation, combined direct and indirect heating}
- F26B 23/02: using combustion heating ({F26B3/305, F26B13/186, F26B21/001, } F26B23/10 take precedence)
- F26B 25/005: {Treatment of dryer exhaust gases (incineration of volatiles F26B23/022)}
- F26B 25/007: {Dust filtering; Exhaust dust filters}
- E01C 2019/109: {Mixing containers having a counter flow drum, i.e. the flow of material is opposite to the gas flow}
- E01C 2019/1095: {Mixing containers having a parallel flow drum, i.e. the flow of material is parallel to the gas flow}
- E01C: CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR (forming roads or like surfaces by compacting or grading snow or ice E01H)
- F26B: DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM (drying devices for combines A01D41/133; racks for drying fruit or vegetables A01F25/12; drying foodstuffs A23; drying hair A45D20/00; body-drying implements A47K10/00; drying household articles A47L; drying gases or vapours B01D; chemical or physical processes for dewatering or like separating liquids from solids B01D43/00; centrifugal apparatus B04; drying ceramics C04B33/30; drying yarns or fabrics in association with some other form of treatment D06C; drying frames for laundry without heating or positive air circulation, domestic laundry-or spin-driers, wringing or hot pressing laundry D06F; furnaces, kilns, ovens F27)

## Abstract

An apparatus for controlling the angular velocity and slope angle of a hot mix asphalt drum as a function of the temperature gradient across the drum outlet. Uneven gas outlet temperature indicates that the veil of RAP (Recycled Asphalt Pavement) in the drum is insufficient. The veil is increased by increasing drum speed. The complete recycled asphalt pavement hot mix asphalt plant uses uneven gas outlet temperatures to change drum operating parameters.

## Claims

### Claim 1

A counterflow drum mixer for production of hot mixed asphalt (HMA) comprising in combination:
said drum mixer having a hot gas inlet and means for generating hot gas;
said drum mixer having a gas outlet;
said drum mixer having a veil of falling HMA within said drum mixer;
an array of gas temperature sensing means located at said outlet for detecting gas temperature; and
means responsive to a gas outlet temperature rise, not detected on all of said sensing means, for changing at least one drum operating parameter of said drum which changes said veil of falling HMA.

### Claim 2 (depends on 1)

The apparatus in accordance with claim 1 wherein said parameter is drum angular velocity.

### Claim 3 (depends on 1)

The apparatus in accordance with claim 1 wherein said drum parameter is slope angle.

### Claim 4 (depends on 1)

The apparatus in accordance with claim 1 wherein said gas temperature sensing means is an array of thermocouples.

### Claim 5 (depends on 4)

The apparatus in accordance with claim 4 wherein said thermocouples are aligned across the gas outlet.