Hot mix asphalt plant with catalytic reactor
US5478530A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 22, 1994 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Sep 22, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A50/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An HMA plant has a catalytic reactor which can effectively and reliably reduce VOC and NO.sub.x emissions produced during plant operation. The reactor effectiveness is enhanced by exhausting the gas stream from a primary dryer of the plant at a sufficiently high temperature for effective catalytic reaction. Since withdrawal of gases from the dryer at these elevated temperatures necessarily reduces the effectiveness of the dryer, overall plant efficiency is maintained by using the treated gas stream from the catalytic reactor to heat further the aggregate in a secondary dryer, which is preferably a finishing dryer/mixer such as a fixed sleeve dryer drum coater. Poisoning of the catalyst is avoided by removing at least a large portion of the dust in the gas stream via a high efficiency cyclone prior to introducing the gas stream into the catalytic reactor. Ammonia or urea may if desired also be injected into the gas stream prior to its introduction into the catalytic reactor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.