Corrosion resistant tubular air preheater
US4034803A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1975 |
| Grant date | Jul 12, 1977 |
| Priority date | — |
| Expiry date | Jul 24, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S165/901
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A corrosion resistant tubular air preheater in which combustion air is heated by heat transfer from flue gases from a furnace. The heat exchanger is of a longitudinal type having a central enclosure of rectangular cross-section in which a plurality of tubular heat transfer elements are mounted. Surrounding the central enclosure is an outer plenum. Cold combustion air enters at the bottom of the outer plenum and circulates around and up the plenum to a series of openings on top of the heat transfer elements. The partially heated combustion air then passes downwardly through metal tubes in the heat transfer elements and then passes outwardly to the furnace. The minimum temperature in metal structure enclosing the combustion gases is controlled by two means. One is the use of insulation in selected areas to limit heat transfer rate to cold air impinging upon metal surfaces. The second method is by control of cold air flow incidence on or along heat transfer surfaces so as to minimize rapid heat transfer from any metal surface, which might chill the surface below the dew point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.