Feeding assembly for feeding a fuel gas containing hydrogen to a burner of a boiler and boiler comprising said feeding assembly

Abstract

A feeding assembly for feeding at least one fuel gas to a burner of a boiler has a feeding duct configured to feed to the burner a feeding flow of fuel gas in a feeding direction; and a safety device, which is arranged in the feeding duct and is shaped so as to define a stagnation zone configured to contain a return flow of gas from the burner in the feeding duct in a return direction substantially opposite to the feeding direction.

1 - 16 . (canceled) 
     
     
         17 . A feeding assembly for feeding at least one fuel gas to a burner of a boiler, the feeding assembly comprising:
 a feeding duct configured to feed to the burner a feeding flow of fuel gas in a feeding direction; and   a safety device, which is arranged in the feeding duct and is shaped to define a stagnation zone configured to contain a return flow of gas from the burner in the feeding duct in a return direction substantially opposite to the feeding direction.   
     
     
         18 . The feeding assembly as claimed in  claim 17 , wherein the safety device is arranged in the feeding duct so as to define at least one passage restriction for the feeding flow of the fuel gas. 
     
     
         19 . The feeding assembly as claimed in  claim 18 , wherein the safety device comprises at least one flow rectifier element, which is arranged in the at least one passage restriction and is configured to determine a laminar feeding flow of the fuel gas in the respective at least one passage restriction. 
     
     
         20 . The feeding assembly as claimed in  claim 19 , wherein the at least one flow rectifier element is configured to dissipate heat transmitted by the gases of the return flow to the safety device. 
     
     
         21 . The feeding assembly as claimed in  claim 17 , wherein the safety device comprises a stagnation chamber, which delimits the stagnation zone and is provided with an inlet opening directed toward the burner defining an access to the stagnation chamber. 
     
     
         22 . The feeding assembly as claimed in  claim 21 , wherein the inlet opening defines the only access to the stagnation chamber. 
     
     
         23 . The feeding assembly as claimed in  claim 17 , wherein the safety device comprises a blocking wall, which delimits, at least in part, the stagnation chamber and extends transversely with respect to the feeding direction. 
     
     
         24 . The feeding assembly as claimed in  claim 23 , wherein the blocking wall has an aerodynamic profile in the feeding direction. 
     
     
         25 . The feeding assembly as claimed in  claim 23 , wherein the blocking wall comprises a first portion having a first face of impact with the feeding flow of the fuel gas in the feeding direction, and a second portion having a second face of impact with the feeding flow of the fuel gas in the feeding direction; the first and second faces being oriented so as to determine between them a leading edge for the feeding flow of fuel gas in the feeding direction. 
     
     
         26 . The feeding assembly as claimed in  claim 25 , wherein the first and second faces are oriented so as to determine between them a leading angle comprised between 10° and 120°. 
     
     
         27 . The feeding assembly as claimed in  claim 23 , wherein the safety device comprises a first lateral wall and a second lateral wall, each of which is arranged at a respective end of the blocking wall so as to define the stagnation chamber together with the blocking wall; the first lateral wall and the second lateral wall extending transversely with respect to the blocking wall. 
     
     
         28 . The feeding assembly as claimed in  claim 27 , wherein the portion of the feeding duct in which the safety device is housed extends along a first longitudinal axis; the first lateral wall and the second lateral wall being substantially parallel to the first longitudinal axis. 
     
     
         29 . The feeding assembly as claimed in  claim 27 , wherein the blocking wall and/or the first lateral wall and/or the second lateral wall are made of a heat conducting material. 
     
     
         30 . The feeding assembly as claimed in  claim 17 , wherein the safety device comprises at least one fixing flap configured to allow the safety device to be secured to a wall of the feeding duct. 
     
     
         31 . A burner assembly comprising the feeding assembly as claimed in  claim 17  and a burner configured to burn fuel gas fed by the feeding assembly. 
     
     
         32 . A boiler comprising the burner assembly as claimed in  claim 31 .