Method for Heating an Industrial Furnace, and Apparatus Suitable for Carrying Out the Method

Abstract

In a known method for heating an industrial furnace by pulsating combustion, gaseous or liquid reactants, comprising an oxidizing agent and fuel, are fed to a burner ( 3 ), with the volumetric flow of at least one of the reactants which emerges from the burner mouth ( 7 ) being changed over the course of time. On this basis, to provide a method which allows a simple and flexible change to the flow during pulsating combustion, according to the invention it is proposed that the change in the volumetric flow of the reactant over the course of time is generated by electrical actuation imparting deflections to at least one membrane ( 14 ) in a membrane space ( 13 ) which is connected upstream of the burner mouth ( 3 ) and is accessible to the reactant, which deflections cause changes to the volume of the membrane space. A low maintenance apparatus of simple design which is suitable for carrying out the method is distinguished by the fact that the device for varying the volumetric flow over the course of time comprises at least one membrane ( 14 ), which is arranged in a membrane space ( 13 ) that is connected upstream of the burner ( 3 ) and is accessible to the reactant, and on which deflections can be imposed by means of an electrical actuation, which deflections cause a change in the volume of the membrane space ( 13 ).

1 - 18 . (canceled) 
   
   
       19 . A method for heating an industrial furnace by pulsating combustion, in which gaseous or liquid reactants, comprising an oxidizing agent and fuel, are fed to a burner, the volumetric flow of at least one of the reactants which emerges from the burner mouth being changed over the course of time, characterized in that the change in the volumetric flow of the reactant over the course of time is generated by electrical actuation imparting deflections to at least one membrane in a membrane space which is connected upstream of the burner mouth and is accessible to the reactant, which deflections cause changes to the volume of the membrane space. 
   
   
       20 . The method of  claim 19 , wherein the electrical actuation is effected by means of an electromagnet by the latter acting on the membrane or on a ferromagnetic body connected to the membrane. 
   
   
       21 . The method of  claim 20 , wherein the electrical actuation of the membrane comprises a control unit. 
   
   
       22 . The method of  claim 19 , wherein the back-flow of the reactant out of the membrane space is avoided or reduced by means of a restricting device provided in the reactant feed. 
   
   
       23 . The method of  claim 22 , wherein the restricting device is designed as a throttle or a diaphragm. 
   
   
       24 . The method of  claim 22 , wherein the volumetric flow of the reactant is constant upstream of the restricting device. 
   
   
       25 . The method of  claim 19 , wherein a minimum level for the volumetric flow of the reactant, which the volumetric flow does not drop below at any time even when the volumetric flow is changing, is predetermined. 
   
   
       26 . The method of  claim 19 , wherein at least two burners are provided fur heating the industrial furnace, with the volumetric flow of the reactant to one burner being changed in the opposite phase to the volumetric flow of the reactant to the other burner. 
   
   
       27 . The method of  claim 26 , wherein the membrane spaces of both burners are arranged adjacent to one another and are separated from one another by a common membrane. 
   
   
       28 . The method of  claim 19 , wherein the volumetric flow of the fuel at the burner mouth is changed. 
   
   
       29 . An apparatus for carrying out the method of  claim 19 , having a burner, which includes feed lines for streams of gaseous or liquid reactants leading to a burner mouth, and having a device for varying the volumetric flow of at least one of the reactants over the course of time, wherein the device for varying the volumetric flow over the course of time comprises at least one membrane, which is arranged in a membrane space that is connected upstream of the burner and is accessible to the reactant, and on which deflections can be imposed by means of an electrical actuation, which deflections cause a change in the volume of the membrane space. 
   
   
       30 . The apparatus of  claim 29 , wherein the electrical actuation comprises an electromagnet, which acts on the membrane or on a ferromagnetic body connected to the membrane. 
   
   
       31 . The apparatus of  claim 29 , wherein the feed line for the reactant leading to the membrane space is provided with a restricting device for avoiding or reducing a back-flow of the reactant. 
   
   
       32 . The apparatus of  claim 31 , wherein the restricting device is designed as a throttle or a diaphragm. 
   
   
       33 . The apparatus of  claim 29 , wherein at least two burners are provided for heating the industrial furnace, it being possible for the volumetric flow of the reactant to one burner to be changed in the opposite phase to the volumetric flow of the reactant to the other burner. 
   
   
       34 . The apparatus of  claim 33 , wherein the membrane spaces of the two burners are arranged adjacent to one another and are separated from one another by a common membrane. 
   
   
       35 . The apparatus of  claim 29 , wherein the membrane space is provided in the feed line for feeding the reactant to the burner. 
   
   
       36 . The apparatus of  claim 35 , wherein the membrane space is provided in the feed line for the fuel.