Mechanical draft controller with vent damper
US4437454A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1982 |
| Grant date | Mar 20, 1984 |
| Priority date | — |
| Expiry date | Mar 22, 2002 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23N2235/04
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A mechanical draft controller integrated in the draft hood of a furnace and coupled to a flue damper is responsive to the draft in the flue for controlling exhaust stack heat loss and eliminating heated room air loss via the draft hood under normal operating conditions. The pressure-sensitive controller is variably positioned as a face damper on a surface of the draft hood and is coupled to the flue damper by means of mechanical linkage. Increasing pressure in the draft hood caused by a reduction in the draft value due to partial flue blockage, large down draft, etc., displaces the pivoted controller resulting in a corresponding opening of the flue damper to re-establish the desired draft value. Similarly, excessive draft causes the displacement of the controller in an opposite direction resulting in flue damper displacement so as to reduce the draft value and exhaust stack heat loss. Between these two operating conditions the controller is variably positioned in the surface of the draft hood so as to block the escape of heated room air via the exhaust stack. A completely blocked flue resulting in an abnormal increase in pressure in the draft hood causes the controller to be furthe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.