Method and apparatus for processing mixed asphalt material utilizing broken-up used asphalt

• US 4,705,404 A
• Filed: 07/11/1986
• Issued: 11/10/1987
• Est. Priority Date: 11/13/1984
• Status: Expired due to Fees

• Current Assignee: Deutsche Asphalt GmbH (Strabag Se)
• Original Assignee: Deutsche Asphalt GmbH (Strabag Se)
• Inventors: Bruggemann, Horst
• Primary Examiner(s): Coe, Philip R.
• Application Number:
  US06/887,092
• Time in Patent Office: 487 Days
• Field of Search: 366/4, 366/7, 366/14, 366/25, 432/105, 432/106, 432/111, 106/281 R, 404/80
• US Class Current: 366/7
• CPC Class Codes: 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
• CPC Class Codes: 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
• CPC Class Codes: E01C 19/105 Mixing or coating by a combination of methods covered by E01C19/1018 - E01C19/104, excluding E01C19/1036
• CPC Class Codes: E01C 19/1063 Controlling the operations E01C19/1068 takes precedence
• CPC Class Codes: E01C 2019/109 Mixing containers having a counter flow drum, i.e. the flow of material is opposite to the gas flow
• CPC Class Codes: E01C 2019/1095 Mixing containers having a parallel flow drum, i.e. the flow of material is parallel to the gas flow

Abstract

A method as well as an apparatus for processing asphalt mixtures is provided in which broken-up used asphalt is employed and new material is added, utilizing a plurality of burner-heated drum devices, with the used asphalt component and the new material for the asphalt mixture to be processed or produced being processed, i.e. heated in particular, in respectively differently configured drum devices. The used asphalt component is heated separately in a drum mixer operated with parallel flow and the new material component is heated in a drying drum operated with counterflow. After leaving their respective drum devices, the components are conducted into at least one further connected mixer and are further treated there with fresh bitumen and possibly with filler material being added in the mixer. Furthermore, the exhaust gases of the drum mixer are introduced directly into the drying drum and are further heated there, thus combusting the CH_x and CO component contained therein.

In this process, the exhaust gases of the drum mixer are introduced into the interior of the drying drum in the immediate vicinity of the burner flame through flow channels in the form of nozzles via a feed device formed at the frontal face of the drying drum in which the burner is disposed, with the direction of the nozzles being adjustable as a function of the size of the burner flame.

Claims

1. In a method for processing mixed asphalt material utilizing broken-up used asphalt and new material utilizing a plurality of burner-heated drums, comprising heating used asphalt in a parallel-flow drum mixer under conditions substantially avoiding damage to the used asphalt, and heating the new material to a temperature higher than the temperature of the asphalt in a counter-flow drying drum, mixing the used asphalt and the new material in a connected mixer while adding bitumen and filler to obtain an asphalt mixture, the improvement comprising

introducing exhaust gases comprising CH_x and CO from the parallel-flow drum mixer directly into the drying drum;

heating the gases to a temperature sufficient to allow the combustion or decomposition of CH_x and CO in the drying drum; and

allowing for the heating gases to further heat the new material in the drying drum to a temperature higher than that of the used asphalt.

2. The method of claim 1 wherein

the gases in the drying drum are heated with a flame.

3. The method of claim 2, wherein

the exhaust gases exiting from the parallel-flow drum are fed into the interior of the drying drum in the immediate vicinity of the flame.

4. The method of claim 3, where

the exhaust gases exiting from the parallel-flow drum are conducted directly into the flame.

5. The method of claim 3, wherein

the exhaust gases exiting from the parallel-flow drum are passed directly by the flame.

6. The method of claim 3, wherein

the exhaust gases exiting from the parallel-flow drum are conducted around the flame in the form of at least a partial jacket stream.

7. The method of claim 1, wherein

the used asphalt is heating in the parallel-flow drum up to about 170°

C.; and

the new material is heated in the drying drum to a temperature between about 180°

C. and 350°

C.

8. The method of claim 1, wherein

the mixing ratio of the used asphalt to the new material is adjustabley regulatable.

9. The method of claim 1 wherein

the amount of used asphalt component is in a considerable majority of the asphalt mixture.

10. The method of claim 1, further comprising

heating the asphalt mixture in the connected mixer to maintain a desired temperature.

11. The method of claim 1, wherein

the ratio of bitumen and filler added into the mixer is adjustaby regulatable.

12. The method of claim 1, further comprising

mixing the asphalt mixture exiting from the connected mixer in a further mixer in communication with said connected mixer.

13. In an apparatus for processing asphalt material utilizing broken-up used asphalt and adding new material, comprising

first and second parallel drum devices, wherein said first device is a parallel-flow mixer for processing the used asphalt, and said second device is a counter-current drying drum for processing the new material;

said first and second devices having material discharge points and said second device having a frontal face provided with apertures and a burner;

at least one mixer;

means for transferring exhaust gas containing CH_x and CO connected said first and said second devices;

means connecting the material discharge points of said first and second devices with said at least one mixer;

the improvement wherein

said means for transferring is connected to said first device at the material discharge point and ends in the form of a feed channel in the frontal face of the second device, said channel being connected through the apertures to the inside of the second device.

14. The apparatus of claim 13, wherein the at least one mixer is a heatable mixer.

15. The apparatus of claim 13, wherein the apertures of the second devices are flow channels.

16. The apparatus of claim 15, wherein the flow channels are nozzles.

17. The apparatus of claim 15, wherein

the flow channels concentrically surround the aperture of the burner.

18. The apparatus of claim 15, wherein

the direction of flow of the channels can be varied as a function of the direction of a flame in the burner.

19. The apparatus of claim 18, wherein all flow channels are coupled with one another.

20. The apparatus of claim 19, wherein all flow channels are controlled in synchronism.

21. The apparatus of claim 20, wherein

the flow channels can be adjusted as a function of flame size.

22. The apparatus of claim 13, further comprising

one other mixer connected to said at least one mixer, said one mixer and said one other mixer being double-shaft positive-flow flow-through mixers.

23. The apparatus of claim 22, wherein the one other mixer is a heatable mixer.

24. The apparatus of claim 22, further comprising

means for feeding bitumen and filler to said one mixer and said one other mixer.