Crude gas torch comprising an adjustable opening cross-section for flaring combustible gases and method for burning crude gases

Abstract

A device for flaring combustible gases, having an adjustable opening cross-section, and three tubes arranged about a common longitudinal axis. The tubes are arranged at least in some sections in a common cross-sectional plane an inner tube is designed as a gas introduction tube and has an opening that ends at the top in the vertical direction a diaphragm that can be adjusted in the cross section, through which the gas stream can be closed or regulated and which is fitted with an automatable mechanism for adjusting the opening cross-section. The device typically contains also at least one air guiding plate, feed devices for an inert gas and an ignition mechanism, thereby ensuring a high reliability for flaring the gas and a low emission of nitrogen oxides and soot. A method for operating the device which is suitable for flaring crude gases which are to be combusted is also disclosed.

1 . An apparatus of a variable opening cross-section for bleeding off/flaring combustible gases, consisting of
 a gas feed tube provided with an opening that ends upwards in vertical direction,   a mixing tube of a larger inner cross-section than the largest outer cross-section of the gas feed tube such that an area is left free between these tubes, the mixing tube consisting of a concentric tube, a diffuser with a cross-section increasing upwards and a confuser with a cross-section increasing downwards,   an inner tube which is arranged around the gas feed tube and is of a larger inner cross-section than the largest outer cross-section of the gas feed tube, and of a smaller outer cross-section than the smallest inner cross-section of the mixing tube,   at least one air guide plate located between the inner tube and the mixing tube,   
       wherein
 a baffle of variable cross-section is arranged at the opening that ends upwards in vertical direction, said diaphragm being used to close or control the gas flow and being equipped with an automatable mechanism for adjusting the opening cross-section. 
 
     
     
         2 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein the baffle consists of plates which are closable concentrically, tangentially and circularly in horizontal direction towards the gas feed tube centre. 
     
     
         3 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein the baffle consists of plates which are closable concentrically, secantially and directly horizontally in direction of the gas feed tube centre. 
     
     
         4 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein the baffle consists of plates which are tilted upwards or downwards in vertical direction for opening. 
     
     
         5 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein the baffle can be adjusted by an electric actuator. 
     
     
         6 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein the baffle can be adjusted by a pneumatic actuator. 
     
     
         7 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein at least one nozzle for feeding an inert gas is located at least one point inside the gas feed tube, the inner tube or the mixing tube. 
     
     
         8 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein at least two ignition lances arranged at an angle of 80° to 100° are arranged inside the cross-section of the inner tube or the mixing tube and with the aid which an electric arc or ignition spark can be generated by electric voltage. 
     
     
         9 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 1 , wherein the gas feed tube can be shut off by means of a bleeder/flare valve which is located below the inner tube and the mixing tube. 
     
     
         10 . The apparatus of a variable opening cross-section for bleeding off/flaring combustible gases according to  claim 9 , wherein the bleeder/flare valve comprises at least one float cup consisting of two compartments, with said compartments to be opened, controlled and closed independently of each other. 
     
     
         11 . A method for the combustion of crude gases by means of a contrivance according to  claim 1 , wherein the inlet pressure and/or the discharge velocity of the gas to be bled off is adjusted by a baffle of variable cross-section. 
     
     
         12 . The method for the combustion of crude gases according to  claim 11 , wherein the ratios of the cross-sections of the gas feed tube and the inner tube as well as of the inner tube and the mixing tube are selected in such a way that the reduced air feed rate to the inner tube leads to a sub stoichiometric combustion air ratio in the inner tube and the proportionately increased air feed rate via the annular gap between the mixing tube and the inner tube to the mixing tube leads to a hyperstoichiometric combustion air ratio above the inner tube. 
     
     
         13 . The method for the combustion of crude gases according  claim 11 , wherein the discharge velocity of the escaping gas to be bled off/flared remains constant during bleeding off/flaring. 
     
     
         14 . The method for the combustion of crude gases according to  claim 11 , wherein an inert gas is fed into the gas feed tube, the inner tube or the mixing tube. 
     
     
         15 . The method for the combustion of crude gases according to  claim 14 , wherein the inert gas is water vapour. 
     
     
         16 . The method for the combustion of crude gases according to  claim 14 , wherein the inert gas is a mixture of water vapour and gas to be bled off/flared. 
     
     
         17 . The method for the combustion of crude gases according to  claim 14 , wherein the inert gas is supplied at a pressure of 7 to 15 bar. 
     
     
         18 . The method for the combustion of crude gases according to  claim 11 , wherein the two compartments of the float cup of the bleeder/flare valve can synchronously be opened, controlled or closed by a pneumatic cylinder.