Flow sensor furnace control

Patent · Tue Nov 24 04:00:00 EST 1987

OSTI ID:5569089

Johnson, R G

In a heating system having a combustion changer with a fuel burner, an induced draft air blower, a control system including an electrically controlled fuel valve for controlling a supply of fuel to the burner, and an exhaust tack for exhausting combustion products, the improvement is described comprising: means enabling a dynamic flow between the interior of the exhaust stack and the external ambient atmosphere including a flowmeter housing connected between an opening provided in the wall of the exhaust stack and the external ambient atmospheres; an electronic flowmeter disposed in the chamber for directly sensing the rate and direction of flow through the chamber and producing electrical output signals indicative thereof, and the flowmeter comprising: a thin film heater suspended in air; and a pair of thin film heat sensor suspended in air and disposed on opposite sides of the heater; and means connecting the electronic flowmeter output signals with the fuel valve, wherein the signals are used to control the fuel valve when predetermined conditions are indicated.

• Assignee: Honeywell Inc., Minneapolis, MN
• Patent Number(s): US 4708636
• OSTI ID: 5569089
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
421000* -- Engineering-- Combustion Systems
BLOWERS
BURNERS
COMBUSTION CHAMBERS
COMBUSTORS
CONTROL EQUIPMENT
DESIGN
ELECTRONIC EQUIPMENT
EQUIPMENT
EXHAUST SYSTEMS
FLOW REGULATORS
FLOWMETERS
FUEL FEEDING SYSTEMS
FUEL SYSTEMS
FURNACES
HEATERS
MEASURING INSTRUMENTS
METERS
MONITORING
TEMPERATURE MONITORING
VALVES