Abstract: A boiler control system for boilers fired by solid fuels wherein the fuels are carried through the combustion zone of the boiler on a traveling grate and wherein the air flow for combustion as supplied to the undergrate region utilizes a control of the fuel rate from a deviation of the outlet pressure from the desired value with the control of the air flow to the undergrate region maintained generally in proportion to the steam flow from the boiler with the proportionality being biased from the deviation of the outlet pressure from its desired value.

Abstract: Apparatus and method for changing the calibrated linkage relationship between two flow control devices of combustion apparatus without impeding the normal operation of the associated process. Means are provided, responsive to remote, manual or automatic control, to calibrate a jackshaft linkage type of control apparatus in order to provide for range changes and zero adjustment.

Abstract: An electronically controlled space heater includes a ceramic block heating element fed by a metering pump with fixed volume charges of liquid fuel at a rate dependent on temperature requirements. The heating element is located within a combustion chamber. Exhaust gases vented from the combustion chamber are applied directly to a thermocouple whose voltage output is utilized to vary or maintain the frequency of a pulse circuit driving the metering pump. An operator-adjustable potentiometer functions as a thermostat to establish a desired temperature reference value to which the thermocouple output is continuously compared. Start-up and shutdown circuitry precludes the development of unsafe operating conditions.

Abstract: A method and apparatus for controlling combustion in a process heater provides for efficient control of the combustion with a minimum of components. The apparatus includes means for generating a signal from a condition of a process, such as temperature, or pressure in the case of a boiler. The signal, which may be a pressure signal, is presented in parallel to a needle valve, to a first fluid-responsive relay, and to a second fluid-responsive relay. A volume tank is connected in series to the needle valve and in parallel to the first relay and to the second relay. The first relay communicates with means for controlling the flow of combustion air. The second relay communicates with means for controlling the flow of fuel. When the signal of the process condition is below the point at which a controller is set, then the signal is an increasing pressure signal. When the signal of the process condition is above the point at which the controller is set, then the signal is a decreasing pressure signal.

Abstract: Apparatus is provided for constructing an induced draft 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, fuel and combustion products into, through and out of the combustion chamber. A flow-limiting orifice in the exhaust stack in proximity to the blower causes a region of higher pressure to exist upstream from the orifice, with a region of lower pressure downstream from the orifice. A pressure signal representative of the flow rate of exhaust stack gases is sensed on one side of the orifice and is fed back to a modulating gas valve which controls the outlet gas flow from the valve to be proportional to the magnitude of the pressure signal representing exhaust stack flow rate. By selecting blower speeds and flow capacities, various firing rates for the furnace can be selected, from the design maximum of the furnace down to various derated levels.

Abstract: Furnace performance is controlled during start-up or very low load operation at a time when the minimum air flow required to be supplied to the furnace is significantly greater than that required to burn the fuel being supplied to the furnace. Decreased furnace heat absorption is accomplished by supplying a larger quantity of the air immediately adjacent the fuel input location for the purpose of diluting the combustion gases and immediately decreasing their temperature level. Increased furnace heat absorption is obtained by introducing a greater portion of the air flow into the furnace at a location remote from the fuel being burned so that the gases at the fuel location remain at a high temperature, and transfer heat to the walls, before being diluted by the incoming air.

Abstract: In a power plant, a solid state sequence is provided for starting an FD or ID fan, or for changing the fan speed in response to the position of the fan inlet vanes. The sequential process is self-calibrated since process events control the stepping operation of the sequencer. At the operating fan speed, boiler air flow and pressure are controlled by fan inlet vane position in accordance with plant load demand. When the fan speed is changed, a multiplier circuit causes the fan inlet vanes to reposition so as to minimize air flow changes as the fan speed changes. When one of multiple FD fans or multiple ID fans has its speed changed at a time a fan balancer control, which normally equalizes air flow, is biased to permit different fan flows through the different speed FD or ID fans.

Abstract: A system for heating a furnace having a heating chamber defined by furnace walls is provided with a plurality of individual burner assemblies mounted on a furnace wall to direct heating gas streams into the heating chamber, each of the burner assemblies including a diffusion chamber, a burner arranged to direct products of combustion through the diffusion chamber into a furnace heating chamber and means for directing the flow of diffusion gases into the diffusion chamber to admix with the burner products of combustion so that the gas stream entering the furnace heating chamber has a greater mass velocity than the burner products of combustion, there being provided a diffusion gas supply means connected to the heating chamber of the furnace for delivering hot gases from the furnace heating chamber to the diffusion chambers of each of the burner assemblies.

Abstract: This metal heating method includes burning an air-gas fuel mixture as it flows into a furnace, flowing hot exhaust gases out of the furnace to an exhaust stack after it has impinged on or been brought into association with the metal in the furnace for heating the same, and thereafter measuring the temperature of gases in the stack. This gas temperature is used for controlling the pressure of the air and also of the gas fuel supplied to the furnace for combustion and with the pressure supplied being reduced when temperatures excessive to predetermined temperatures exist in the stack, but at the same time, a desired high fuel-to-air ratio is maintained to provide a reducing atmosphere in the furnace.

Abstract: A device for the setting and automatic regulation of the mixture ratio of a gas/air mixture for industrial furnaces comprises two coaxially-arranged diaphragm pressure gauges, connected in opposition, via a ratio setting mechanism, for the gas and the air, and a throttle member, controlled by the diaphragm displacement, in the gas or the air feed pipe. The two diaphragm pressure meters each are oppositely acted upon on only one side by the gas pressure or the air pressure respectively. The throttle member is controlled directly by the diaphragms. The diaphragm pressure gauges and the ratio setting mechanism together with the throttle member are designed as a structural unit.

Abstract: A gas mixer and reactor is provided which includes an elongated gas flow chamber with a nozzle arrangement at its inlet end for passing a first gaseous reactant into the interior of the chamber, toward the outlet of the chamber from points uniformly about the inner periphery of the chamber, and an annular nozzle arrangement near the outlet of the gas flow chamber for directing another gaseous reactant, or reactants, through the outlet of the gas flow chamber and into a thermal reaction chamber which communicates with the outlet of the gas flow chamber. In this manner controlled amounts of gaseous reactants may be thoroughly admixed and reacted to produce an atmosphere of desired composition. Atmospheres for kilns having controlled amounts of free hydrogen, carbon monoxide, oxygen, or carbon for example, are produced by burning controlled ratios of fuel, air and in some cases an inert gas, mixed by the reactor.

Abstract: A cyclonic, multiple vortex type fuel burner having a combustion chamber with a closed curved end, with the main fuel and auxiliary fuel and air being tangentially injected into the chamber adjacent to the curved end creating a circular oriented combustion of the fuel, with the air being injected at varying quantities along the length of the combustion chamber, all to provide a controlled temperature in the burner chamber that burns all the combustible materials in the fuel and turns the non-combustible materials into dry slag or wet slag without burning the refractory materials forming the combustion chamber. The burner feeds a volume of air and fuel through fixed openings into the combustion chamber to provide a preset fuel/air ratio disribution along the length of the combustion chamber. This fuel/air ratio is subject to change with changes in the amount or density of fuel fed to the burner.