Batch asphalt plant having RAP weigh hopper and pugmill scavenging system
US5423606A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 7, 1993 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Dec 7, 2013 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE01C2019/1095
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A designated amount of recycled asphalt product (RAP) is fed to the pugmill of a batch asphalt plant during the production of hot mix asphalt (HMA) at a controlled rate so as not to overload the pugmill scavenging system. The designated amount of RAP is metered in a RAP weigh hopper, stored temporarily in a RAP holding hopper, and is then fed from the RAP holding hopper to the pugmill at a controlled rate. The feed of RAP to the pugmill, though electronically initiated, is preferably manually or automatically adjustable so as to avoid overloading the pugmill scavenging system while at the same time assuring adequate mixing of the RAP with the virgin aggregate and liquid asphalt. The scavenging system directs vapors removed from the pugmill to the dryer and preferably includes electronically operated dampers connecting the combustion air inlet of the dryer to the pugmill only during the mixing operation and otherwise connecting the combustion air inlet to the ambient atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.