Pilot gas bypass system for fuel-fired furnaces
US4926840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1989 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Sep 28, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF24H9/0036
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
To inhibit internal heat exchanger corrosion, the products of combustion from a standing pilot flame in an induced draft, fuel-fired furnace are prevented from migrating through the heat exchanger during idle periods of the furnace by flowing the products of combustion upwardly through a small vent tube into the outlet section of the draft inducer fan, and then into an external exhaust stack, thereby bypassing the heat exchanger. During operation of the draft inducer fan a negative pressure is maintained within the vent tube, to prevent combustion gas outflow therethrough which might otherwise snuff out the pilot flame, by a venturi structure positioned within the draft inducer fan outlet section adjacent its juncture with the vent tube.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.