Abstract: An oxy-combustion firing configuration, process, and apparatus can reduce the consumption of oxygen and fuel in an oxy-fuel combustion processes. Processes in accordance with the present invention include operation of an automated logic control device which controls an oscillating valve and controller. The valve and controller are used to oscillate the fuel and/or oxygen supplied to individual burners in a furnace. The oscillating parameters, such as frequency, amplitude, duty cycle, and phase difference between individual burners and their stoichiometry ratio are set to initiate preferable oxy-combustion in that furnace. Selective burner placement in the furnace enables the formation of deflagration zones which can provide very intense heating and complete combustion.

Abstract: A thermal protection system for a chemical vapor deposition machine (CVD). The system of the present invention includes a thermal sensor for providing a temperature signal corresponding to a CVD chamber temperature, a heating component for heating the CVD chamber, and a controller for regulating the CVD chamber temperature. The controller is coupled to receive the temperature signal and to control the heating component in response thereto. An interlock circuit is coupled between the heating component and the controller. The interlock circuit has an open state and a closed state. A comparison circuit is coupled to receive the temperature signal and coupled to control the interlock circuit, wherein the comparison circuit effects a comparison between the temperature signal and a reference and commands the interlock to the open state when the temperature signal exceeds the reference.

Abstract: A process and apparatus for oxygen-enriched combustion of a fuel in an industrial furnace in which a preheated primary oxidant from a heat exchanger and a fuel to be combusted are introduced into a combustion chamber and ignited, a secondary oxidant having an oxygen concentration in excess of the concentration of oxygen in air is introduced into the combustion chamber downstream of the flame, and the resulting combustion products are exhausted. In accordance with one embodiment, the secondary oxidant comprises preheated oxidant aspirated from the heat exchanger using industrial-grade oxygen, resulting in an oxygen-enriched mixture being injected into the combustion chamber downstream of the flame. As a result, NO.sub.x emissions are reduced without adverse effects on the overall furnace operation.

Abstract: An air heating apparatus for air that is to be supplied to a blast furnace. The apparatus includes a number of separate air heater devices connected together in series flow relation so that the total temperature increase is the sum of the heating actions produced in the individual devices. Each device includes a tube-shell heat exchanger and a plurality of burner units oriented around the shell to direct flames against outer surfaces of the tubes.

Abstract: An apparatus such as a crucible furnace for heating a vessel such as a crucible comprises an enclosure surrounding the vessel so that a flow path exists between the enclosure and the vessel which has an outer surface forming the inner boundary of the flow path. The flow path extends all around the vessel. First and second gas fired burners open into the flow path to discharge their hot combustion product gases into the path. Associated with each burner is a respective heat regenerator. When the first burner is in firing mode its emitted hot combustion product gases circulate around the flow path and leave through the second burner, which is in flueing mode, and heat the associated regenerator. Then when the second burner is in firing mode that heated regenerator heats the combustion air used by the second burner.

Abstract: A system for preheating air being fed to a continuous fired furnace by means of high temperature waste gases exhausted from the furnace. The system includes two pairs of interconnected regenerators. The regenerators of one pair are alternately connected by means of a reversing valve to an ambient air inlet and a waste gas exhaust stack, and the regenerators of the other pair are alternately connected by means of a second reversing valve to the furnace's waste gas outlet duct and combustion air inlet duct.

Abstract: A method and system is provided for controlling a selected zone in a fuel fired furnace of the type used for heating work as it moves through the zone from an entrant end to an exit end. The method and system includes providing a fuel fired burner at the exit end for propelling a flame toward the entrant end of the zone, controlling the firing rate or capacity of this flame in accordance with the temperature of the work adjacent the exit end of the zone, continuously establishing a gas temperature for the entrant end of the zone corresponding to the firing rate of the flame and then continuously controlling the length of the flame to obtain the established gas temperature at the entrant end of the zone. The combined adjustment of capacity and flame length in accordance with the measured temperature at the entrant end of the zone controls the heating profile through the zone and increases the efficiency of the heating zone.

Abstract: A method and system is provided for controlling a reheating furnace having entrance and discharge ends, a preheating zone at the entrance end, and heating and soaking zones sequentially adjacent the preheating zone in the direction toward the discharge end, and an exhaust gas flue at the entrance end. The method and control system provides for obtaining an optimum temperature profile through the preheating and heating zones with minimum fuel consumption in connection with operation of the preheating zone by controlling the fuel supply to the preheating zone in accordance with the rate or quantity of fuel flow to the heating zone and the temperature of the exhaust gas from the furnace.

Abstract: A method of controlling steel strip temperature in a process of continuously heating steel strip in heating equipment having a preheating zone and a rapid-heating zone. The preheating zone has a number of gas-injecting preheating units that can be individually put into and taken out of operation. In normal operation, the in-operation length of the preheating zone is prefixed irrespective of strip thickness, and the temperature of the rapid-heating zone is preset depending on the strip thickness so that the strip acquires the desired temperature at the exit end thereof. In such operation, the strip is preheated in the preheating zone of the prefixed in-operation length and rapidly heated in the rapid-heating zone at the preset temperature. In irregular operation, such as treating a following strip the thickness of which has changed, the temperature of the rapid-heating zone is changed from the preset one to a second one optimum for the following strip.

Abstract: Separate intake air and exhaust gas manifolds along each long checker-brick regenerator, each of which manifolds have separate adjustable sideports, valves, or gates in each branch duct that do not have to be readjusted each regeneration cycle, and which gates may be preadjusted and/or at-will adjusted from a common and even remote location.