Apparatus and Method for Burning a Fuel

Abstract

A novel device is described for combusting a liquid or powdered fuel having an atomizer nozzle ( 2 ), which has a valve configuration ( 41 ) for the control of the supply of the fuel, a compressed air connection ( 4 ), a mixing chamber ( 38 ) for mixing the fuel with compressed air, and a nozzle opening ( 23 ) for atomizing a mist of fuel in compressed air. A supply line ( 28 ) for the fuel and a preheating apparatus ( 5 ) are provided, which are attached in a nozzle assembly surrounding the nozzle ( 2 ). Furthermore, air channels in a sheath ( 3 ) enclosing the preheating apparatus ( 5 ) and a fastening sleeve ( 13 ) having connection channels adjoining the air channels are provided, the sheath ( 3 ) forming a ring gap ( 21 ) for the supply and heating of the compressed air with the nozzle assembly ( 12 ) of the atomizer nozzle ( 2 ). Air supply lines ( 50 ) are provided in the nozzle body ( 20 ) originating from the ring gap ( 21 ) in such a way that the valve configuration ( 41 ) is activatable by the compressed air.

1 . A device for combusting a liquid or powdered fuel having an atomizer nozzle ( 2 ), which has a valve configuration ( 41 ) for controlling the supply of the fuel, a compressed air connection ( 4 ), a mixing chamber ( 38 ) for mixing the fuel with compressed air, and a nozzle opening ( 23 ) for atomizing a mist of fuel in compressed air, having a supply line ( 28 ) for the fuel and having an apparatus ( 5 ) for preheating the fuel to a predetermined temperature, which is provided in a nozzle assembly surrounding the nozzle ( 2 ), characterized in that air channels are provided in a sheath ( 3 ) enclosing the preheating apparatus ( 5 ) and a fastening sleeve ( 13 ) having connection channels adjoining the air channels, the sheath ( 3 ) forming a ring gap ( 21 ) for the supply and heating of the compressed air with the nozzle assembly ( 12 ) of the atomizer nozzle ( 2 ), and the air supply lines ( 50 ) originating from the ring gap ( 21 ) being provided in the nozzle body ( 20 ) in such a way that the valve configuration ( 41 ) is activatable by the compressed air. 
   
   
       2 . The device according to  claim 1 , characterized in that the valve configuration is formed by a clamped diaphragm ( 41 ) or by a compression disk ( 84 ), and the nozzle ( 2 ) has an axial fuel channel ( 36 ) terminated by the diaphragm, and the air supply lines ( 50 ) radially enclose the fuel channel and encounter the diaphragm or the compression disk. 
   
   
       3 . The device according to  claim 2 , characterized in that at least two air supply lines ( 50 ) are provided, which are situated at an equal distance diametrically opposite to the fuel channel. 
   
   
       4 . The device according to  claim 2 , characterized in that the mixing chamber is formed by a ring groove ( 38 ) enclosing the fuel channel ( 36 ), into which the air supply lines ( 50 ) open. 
   
   
       5 . The device according to  claim 1 , characterized in that the nozzle assembly is formed by a connection sleeve ( 12 ) having a throttle ( 14 ) for decreasing the flow rate and the fuel pressure. 
   
   
       6 . The device according to  claim 5 , characterized in that the connection sleeve ( 12 ) is fastened liquid-tight to the transition sleeve ( 13 ) and the transition sleeve ( 13 ) is fastened liquid-tight to the nozzle body ( 2 ). 
   
   
       7 . The device according to  claim 6 , characterized in that the connection sleeve ( 12 ) is fastened to the transition sleeve ( 13 ) using a screw connection and the transition sleeve ( 13 ) is fastened to the nozzle body ( 20 ) using a screw connection. 
   
   
       8 . The device according to  claim 1 , characterized in that a flame pipe ( 55 ), preferably made of a ceramic or internally lined with ceramic fibers, is provided at the outlet of the atomizing nozzle ( 2 ), which is essentially tapered at the rear end facing toward the atomizing nozzle ( 2 ), so that a recirculation gap is formed between a fastening pipe and the flame pipe ( 55 ). 
   
   
       9 . The device according to  claim 1 , characterized in that the solenoid valve ( 73 ) is provided before the compressed air connection ( 4 ), which is switched using a time delay relay ( 64 ) via a burner controller, to heat the fuel during a predetermined time and, after passage of this time, to open the valve configuration ( 41 ) and start the burning procedure. 
   
   
       10 . A method for combusting a fuel using a device according to  claim 1 , characterized in that a liquid or powdered fuel is preheated in a supply line ( 28 ) using a preheating apparatus ( 5 ) and supplied to a valve configuration ( 41 ), compressed air is preheated in direct proximity to the preheating apparatus ( 5 ) and supplied via air supply lines ( 50 ) in the nozzle body ( 20 ) to the valve configuration ( 41 ) in such a way that the compressed air activates the valve configuration ( 41 ). 
   
   
       11 . The method according to  claim 10 , characterized in that the compressed air opens the valve configuration ( 41 ) after a time delay to preheat the fuel during a predetermined time using the preheating apparatus ( 5 ) and to start the burning procedure after passage of this predetermined time.