Adjustable orifice plate for exhaust ducts
US6772753B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 2002 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | Aug 10, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF26B25/009
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust duct orifice adjustment device for a gas-fired heater used to indirectly heat an oven communicating with a heat exchanger, wherein the exhaust duct includes a fixed annular orifice plate and a switch having a pressure sensor on opposed sides of the fixed orifice plate, turning off the burner if the pressure drop falls below a predetermined minimum. The orifice adjustment mechanism includes a moveable plate upstream of the fixed orifice plate having an opening communicating with the opening in the fixed orifice plate and an adjustment mechanism moving the orifice adjustment plate from a retracted position, wherein the opening through the fixed orifice plate is substantially unobstructed, to an extended position which restricts the opening through the fixed orifice plate, thereby adjusting the pressure drop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.