Mass flow control system and method for asphalt plant
US5887583A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1996 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Jul 31, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/0363
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
As electronic programmable valve positioning linkage for a burner used in a hot mix asphalt plant is associated with fuel, air and optionally flue gas recirculation valve motors. To avoid an undesired rich condition which might result in an explosive condition, the linkage employs a program logic which changes a valve position, depending on increase or decrease of the burner output, in response to a temperature controller and thereby maintain an acceptable lean condition. The air valve motor is controlled by the temperature controller when burner output is to be increased with the fuel valve motor following the air valve motor, and the fuel valve motor is controlled when the burner output is to be decreased with the air valve motor following the fuel valve motor. In conjunction with the linkage, a mass flow system can be provided to calculate fuel/air and/or flue gas recirculation ratios based upon measurement of air flow, fuel flow and flue gas flow. In such a mass flow system, the linkage acts as a backup for maintenance purposes and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.