Abstract: A burner for burning a combustible gas comprising fuel gas and air that has been mixed before being supplied to the burner. The burner has a flame holder concavely recessed into a flame outlet. The concave configuration of the flame holder focuses the individual flames on the combustion surface toward a central location where the individual flames interact with and reinforce one another in a direction axial to the burner. Thus very little heat is transmitted directly from the burner in a direction normal to the burner axis. This characteristic of the burner allows it to be used to fire a flue type heat exchangers where the walls of the heat exchanger are very close to the burner without excessive temperatures being produced in the heat exchanger walls adjacent the burner.

Abstract: A refrigerant recovery system is operated to withdraw compressible refrigerant from a refrigeration system by first withdrawing liquid refrigerant from the system being serviced through a suitable conduit and delivering the withdrawn refrigerant directly to a refrigerant storage means. In the refrigerant storage means at least a portion of the refrigerant so withdrawn exists in gaseous form and a portion of this is withdrawn from the storage means and passed serially through a compressor, a condenser, and a refrigerant expansion device before being delivered back to the refrigerant storage means where is evaporates and absorbs heat from the refrigerant within the storage means thereby cooling the storage means and lowering the pressure therein to thereby increase the withdrawal of the liquid refrigerant from the refrigeration system through the conduit. The system controlled parameters including temperature of the refrigerant and the storage means, and compressor suction and discharge pressure are sensed.

Abstract: A refrigerant recovery device for recovering compressible refrigerant from refrigeration system. The system includes in serial fluid communication, a compressor, a condensor, and a means for storing refrigerant. An expansion device is provided in the fluid line interconnecting the condensor and the storage means. A four way valve is provided which has one port interconnected with the refrigeration system being serviced, another port interconnected with the suction side of the compressor and two additional ports in fluid communication with the means for storing refrigerant. The four way valve may be actuated to recover liquid refrigerant from the refrigeration system being serviced by establishing a first path from the system being serviced directly to the means for storing refrigerant.

Abstract: A method and apparatus for sampling the purity of refrigerant flowing through a refrigeration system is provided. A refrigerant sampling chamber is operably connected and parralel fluid flow communication with a compressor of the refrigeration system. Operation of the compressor to establish the flow of refrigerant through the system results in withdrawal of a quantity of refrigerant from the high pressure side of the system. The withdrawn refrigerant passes through the refrigerant sampling chamber and a refrigerant quality testing tube contained therein. Following passage through the test chamber the withdrawn refrigerant is returned to the low pressure side of the refrigeration system.

Abstract: A method and apparatus for recovering and purifying refrigerant contained in a refrigeration system has a first mode of operation wherein refrigerant is withdrawn from the system being serviced, compressed, condensed and delivered in liquid form to a refrigerant storage means. The pressure ratio across the recovery compressor is monitored, and, when the pressure ratio exceeds a value above which the compressor may be adversely affected withdrawal of the refrigerant from the refrigeration system is terminated. The system is then operated in a closed, cooling mode wherein refrigerant recovered from the system and stored in the storage means is withdrawn therefrom by the compressor, compressed condensed, and expanded and returned to the storage means to thereby lower the temperature and pressure of the storage means and the refrigerant contained therein.

Abstract: In a heating appliance employing a radiant burner, a method and apparatus for setting the ratio of gaseous fuel to air supplied to the burner to a desired value. With the gaseous fuel flow rate held constant, the air flow rate is controlled to maintain the fuel-to-air ratio at the desired value. The invention uses a sensor that measures the intensity of radiation emitted by the burner. A control device compares the measured intensity to a reference intensity and regulates the air flow rate such that the measured intensity is equal to the reference intensity. The burner emits radiation equal to the reference radiation intensity when it is burning a combustible gas supply containing the desired fuel-to-air ratio, so that by regulating the air flow rate to cause the burner to emit the reference radiant intensity, the fuel-to-air ratio will be at the desired value.

Abstract: An integrated system for both space and water heating. Heating is accomplished in a condensing heating module having a small hot water storage reservoir to reduce burner cycling during periods of low demand. The space heating system includes a fluid flow loop with a fluid circulating pump for circulating a heat transfer fluid in the loop from the heating module to a remote space heating heat exchanger. The heating module can also supply hot water for service use. The system may be configured either as an open loop system, in which the space heating and water heating subsystem are combined and share common lines, or a closed loop system, in which the space heating subsystem fluid flow loop is isolated from the water heating subsystem.

Abstract: A space heating appliance employing a radiant burner that burns a gaseous fuel and a plurality of heat pipes to transfer heat produced by the burner to the air to be heated. The appliance is adaptable for use in outdoor "packaged" units, together with an air conditioning system, for heating ventilation and air conditioning (HVAC) systems in commercial buildings, and is also adaptable for use in indoor residential or commercial applications.

Abstract: A closed refrigeration system is provided with a mass flow limiting device located upstream of the suction inlet of a compressor. The device limits the mass flow supplied to the compressor during pulldown and startup to prevent overloading the motor or engine driving the compressor but has minimal influence on the refrigeration system under equilibrium conditions since it is designed for the specific system parameters.

Abstract: A water heating module. The module is adapted for heating water for general residential and commercial use and as a supply for a hydronic heating system. The module is capable of supplying a large volume of hot water near instantaneously on demand without exhaustion. There is a small hot water tank in the module, to supply small demands and to reduce ambient losses while module is in standby. Condensing combustion gases are used to preheat incoming cold water; both features combining to produce high fuel efficiency in the module. A radiant infrared burner may be used in the module to eliminate combustion roar and also to substantially reduce NO.sub.x emission, thus enabling sale of the module in jurisdictions having strict NO.sub.x emission standards.

Abstract: An induced draft warm air furnace employing a radiant infrared burner. The use of a radiant burner results in a very low concentration of oxides of nitrogen (NO.sub.X), in the combustion gases produced. In addition, the use of a radiant burner eliminates the combustion roar produced by other types of burners found in similar furnaces. Further, the invention allows the attainment of the advantages of a radiant burner in a furnace of otherwise standard design with only minor modification. The scope of the invention includes the use of the radiant burner within a combustion chamber which is either within the heat exchanger enclosure and joined to the heat exchanger or within a burner box mounted external to the heat exchanger enclosure but having means for the free passage of combustion gases from the combustion chamber to the heat exchanger. The use of induced draft eliminates the possibility of combustion gases leaking out of the combustion chamber or heat exchanger.

Abstract: An apparatus and method for use in a combustion system of a gas-fired furnace to inhibit formation of oxides of nitrogen (NO.sub.x) by the combustion system thereby reducing NO.sub.x emissions from the combustion system. The apparatus is made of a material which is positioned at the interface of the primary zone and the secondary zone of a combustion flame produced by a two-zone burner which is part of the combustion system, to temper the combustion flame by absorbing thermal energy from the combustion flame. The device sufficiently tempers the combustion flame to limit peak combustion flame temperatures and residence times at these peak combustion flame temperatures to levels which inhibit formation of oxides of nitrogen.

Abstract: A method and control system are disclosed for operating an integrated heating system for space heating and tankless domestic hot water heating utilizing an infrared burner module and heat exchanger coil. When the system is below 100% capacity, the burner is pulsed using a constant pulse period and varying the on-pulse width to vary capacity, or where a minimum on-pulse width is maintained the off-pulse width is varied to vary capacity.

Abstract: A gas-fired condensing furnace with a corrosion resistant condensing heat exchanger. The condensing heat exchanger is formed from a perforated flat sheet of engineering metal with a layer of polymer sheet material laminated thereto. Each condensing heat exchanger has a condensing flow passage of serpentine shape formed in the laminated flat perforated sheet of engineering metal such that the polymer layer is permeated by water condensed from the flue gases, and the permeated water flows through the perforated sheet metal and is not allowed to accumulate at the interface between the engineering metal and the polymer sheet.

Abstract: A liquid-backed gas-fired heating system is disclosed which utilizes an infrared burner module having a helical coil wrapped concentrically thereabout. The helical coil located in the radiant zone and convective zone of the module receives heat from the hot products of combustion and transfers the heat to a circulating fluid, which in turn transfers the heat through a fan coil to the space to be heated.

Abstract: A device is disclosed for use in a combustion system to inhibit formation of oxides of nitrogen (NO.sub.x) by the combustion system thereby reducing NO.sub.x emissions from the combustion system. The device is made of a material, such as stainless steel, which is positioned at the periphery of a combustion flame produced by a burner which is part of the combustion system, to temper the combustion flame by absorbing thermal energy from the combustion flame. The device sufficiently tempers the combustion flame to limit peak combustion flame temperatures and residence times at these peak combustion flame temperatures to levels which inhibit formation of oxides of nitrogen while allowing substantially complete combustion of the fuel supplied to the burner.

Abstract: Domestic tankless water heating is incorporated into a space heating system. The space heating system includes a fluid flow loop with a fluid pump for circulating the fluid in the loop and a remote fan coil for transferring heat to the air in the space to be heated. The heat source is an infrared burner and the heating of the domestic water may be either directly by the burner through radiative and convective heat exchange in an open loop system or by heat exchange in a tube-in-tube heat exchanger which is in series with the fan coil in a closed loop system.

Abstract: A method and apparatus for recovering heat from the combustion gas discharged from a submerged horizontal burner. The burner is at atmospheric pressure while an induction fan reduces the pressure inside the heat exchanger and draws the ignited combustion gas through a submerged combustion chamber and through the liquid to a flue. The liquid flows in counterflow arrangement with the combustion gas which further enhances the heat transfer between the combustion gas and the liquid.

Abstract: A high efficiency induced draft clamshell type heat exchanger for use in a hot air furnace. The geometry of the heat exchanger is such that the various segments are compactly arranged to transfer heat from the fuel to the air passing over the heat exchanger surface while maintaining the discharged products of combustion at a temperature sufficiently high to prevent condensation from forming or collecting within the heat exchanger during steady state operation.

Abstract: A burner for burning a combustible gas comprising fuel gas and air that has been mixed before being supplied to the burner. The burner has a flame holder .[.concavely.]. .Iadd.axially and radially .Iaddend.recessed into a flame outlet. The .[.concave.]. configuration of the flame holder focuses the individual flames on the combustion surface toward a central location where the individual flames interact with and reinforce one another in a direction axial to the burner. Thus very little heat is transmitted directly from the burner in a direction normal to the burner axis. This characteristic of the burner allows it to be used to fire a flue type heat exchangers where the walls of the heat exchanger are very close to the burner without excessive temperatures being produced in the heat exchanger walls adjacent the burner.