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Class 236/15C - Furnace controlled responsive to pressure


Subclass of Class 236 - Automatic temperature and humidity regulation
No. of patents: 31
Last issue date: 08/28/2007


NumberTitleIssue Date
7261243Thermostat responsive to inputs from external devices
A thermostat is provided that receives one or more inputs from at least one heating system of a climate control system, and initiates an appropriate action in response to the input. The thermostat can turn off a heat pump providing substandard heat and responsively ...
08/28/2007
6754541Control system apparatus for loading a value of a system parameter and preventing change thereto after a period of time
A control system for controlling an operating system stores a system parameter such as an ultimate pressure value, for an operating system. The control system allows operation of the operating system only after an initial value of the system parameter has been loade...
06/22/2004
6321744Modulating furnace having a low stage with an improved fuel utilization efficiency
An improved, induced-draft, gas-fired furnace which is adapted to operate at any of a high, medium and low firing rate. A pressure sensing assembly generates differential pressure signals that vary in accordance with the pressure across a heat exchanger a...
11/27/2001
6175207Power up communication interface system
A controller for a system has two or more operating modes. The controller operates according to a different control algorithm in each operating mode. A manually operable switch typically used for sending a reset signal to the controller, may also be used ...
01/16/2001
5522541Method for proving furnace high-heat pressure switch
In a two-stage furnace system, including a thermostat, at least one gas burner with a low and high-fire operating capability, an inducer fan having low and high speed operating settings, and a high-fire pressure switch, a method for handling the high-fire...
06/04/1996
5456597Intelligen transient eliminator for an ignition system
The present invention relates to an intelligent transient eliminator which allows a gas ignition system to prevent gas valves from being turned off by a pressure switch in response to a transient pressure wave. The transient eliminator is preferably provi...
10/10/1995
5249739Apparatus and method for monitoring the operating condition of a burner system
Apparatus and method for sensing the operating condition of a burner temperature as the indicating variable. When the operating status is stable, the flue temperature should be nearly identical to that when the system was known to be in proper condition. ...
10/05/1993
5244147Furnace pressure control method
A method of controlling the pressure in an incinerator for incinerating municipal refuse, industrial waste, etc. Exhaust gas from an incinerator typically passes through an exhaust gas cooler and an exhaust gas treating device and then discharged into the...
09/14/1993
5211331Control in combination with thermostatically responsive assembly
A control assembly in combination with a thermostatically responsive apparatus. In a preferred mode the principles of the present invention are applied to an infra-red heating system of the type including burner assemblies (12, 12') connected in series by...
05/18/1993
5027789Fan control arrangement for a two stage furnace
The present invention involves a two stage furnace and a method of controlling the fans. In the furnace, a high pressure switch indicates whether sufficient air is present to support high combustion. Normally the furnace operates at one of the combustion ...
07/02/1991
4925093Forced draft direct vent system for a water heater
A forced draft direct vent system is provided for an indoor domestic type gas water heater having an atmospheric burner. The forced draft system permits adaptation of the water heater as a combined water heater and space heater in a compact continuous upr...
05/15/1990
4708636Flow sensor furnace control
Disclosed is a heating system having a combustion air blower, a fuel valve for providing fuel to a burner, and an exhaust stack for exhausting combustion products. Also disclosed is flow sensor apparatus operatively associated with the stack for providing...
11/24/1987
4706881Self-correcting microprocessor control system and method for a furnace
A self-correcting control system and method is provided for a furnace to correct certain operating conditions that exceed normal limits. Upon sensing insufficient air flow as a function of the pressure drop across the heat exchangers, the control system a...
11/17/1987
4703747Excess air control
Method and apparatus for maintaining excess air control in a gas furnace. A pressure switch is placed across a heat exchanger to indicate when, while accelerating the inducer motor speed during purging operation, the pressure drop reaches a predetermined ...
11/03/1987
4547144Fuel gas control
Disclosed is a fuel gas control for controlling the delivery of fuel gas. The present gas control comprises an inlet chamber having an inlet for receiving a supply of gas and an outlet chamber having an outlet for providing a supply of gas. The inlet and ...
10/15/1985
4483672Gas burner control system
A burner control system for gas fired apparatus of the powered blower vent type wherein a diaphagm valve for controlling the supply of gas to the main burner of the apparatus is operated by a gas bleed line which is subject to pressure regulation by a ser...
11/20/1984
4427374Recirculation device
A recirculation device for recirculating a selected volume of preheated gas exhausted from a heating chamber in a mixture with fresh air back to the heating chamber. The device comprises a first passageway having an entrance and a pair of exits; a second ...
01/24/1984
4403942Self-checking safety switch control circuit
The present invention relates to a self-checking safety switch control circuit for a power combustion system. The circuit comprises a safety switch, a combustion blower relay, a thermal pilot switch, and a fuel supply system. The safety switch operates to...
09/13/1983
4402303Fan flow control device
A flow control device is provided for use with a fan to prevent pressure excursions in a furnace or any other hardware equipment to which the fan is connected. The control device is connected in parallel relation with respect to the fan so that a recircul...
09/06/1983
4373897Open draft hood furnace control using induced draft blower and exhaust stack flow rate sensing
Apparatus is provided for modifying an open draft hood furnace and its control system, to produce an induced draft furnace having increased efficiency. A blower located in the furnace exhaust stack is used to induce movement of air and combustion products...
02/15/1983
4347869Hydraulic valve position control system for regulating smokestack exhaust pressure
A control system for regulating exhaust gas pressure in a furnace smokestack by means of three power cylinder actuated butterfly valves in the smokestack opening. An electronic control circuit provides digital output signals, which operate spool valve dev...
09/07/1982
4334855Furnace control using induced draft blower and exhaust gas differential pressure sensing
A heating system of the type having a combustion chamber with a fuel burner, an inlet for combustion air and an exhaust stack is improved by adding a variable-speed induced draft blower, a flow-restricting stack orifice and a fuel valve sensitive to the e...
06/15/1982
4262843Method of and apparatus for controlling the feed amount of air for combustion in a natural draft-type heating furnace
A method of and apparatus for controlling the feed amount of air for combustion in a natural draft type heating furnace is disclosed, in which the draft pressure, the oxygen concentration in a combustion gas, the opening degree of a damper for controlling...
04/21/1981
4249890Production of heated bituminous mixes
A process for the production of heated aggregate mix, such as bituminous mix, and a reactor for carrying out the process. In one aspect, the process entails the control of gas flow through a tumbler drum, preferably by controlling exhaust from the drum, i...
02/10/1981
4239477Furnace ignition system with draft control and loss-of-draft protection
A furnace ignition and draft control system includes a damper plate movable under control between a closed and an open position. When a call for heat signal is generated, a holding relay is actuated to energize a damper motor to open the damper provided t...
12/16/1980
4205631Pressure limiting control for an inlet draft fan in an electric power plant
The inlet vanes for an induced draft (ID) fan in a power plant boiler are position controlled in accordance with the furnace pressure to limit the potential destructive power developed by the fan. The ID inlet suction temperature is sensed and a control s...
06/03/1980
4102627Draft tell-tale for fired furnaces
In a fired furnace system having a convection section, and in which control a furnace draft is vital to both fuel conservation and avoidance of furnace damage, apparatus for monitoring the pressure conditions (draft) inside the furnace comprises a first p...
07/25/1978
4096038Method and apparatus for operating a calciner under a pressure differential
Method and apparatus for the heat treatment of volatile containing materials in a rotary hearth type furnace wherein the flue gases emanating from the calciner are employed to create either a positive or negative pressure within the calciner hearth as wel...
06/20/1978
4004730Furnace draft control for a steam generator
A furnace draft control for a fossil fuel fired steam generator wherein the rates of flow of fuel, air and flue gas are adjusted in parallel in accordance with changes in power demand and the forced and induced drafts are adjusted in opposite directions a...
01/25/1977
3985294Furnace pressure control
There has been provided a control for regulating the pressure excursions in a furnace having forced draft and induced draft fans. A pressure detector responsive to pressure in the furnace delivers an output indicative thereof. Circuit means, responsive to...
10/12/1976
3964675Appartus for limiting vacuum and pressure in a furnace
A furnace system having a combustion chamber, and heat transfer surfaces, forced and induced draft fans for moving gas through the burner, chamber, and heattransfer surfaces, first controls for maintaining predetermined gas flows and furnace pressure or d...
06/22/1976
 
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