Combustion membrane for a gas burner

Abstract

A combustion membrane for a gas burner including a fabric having two opposite fabric surfaces, which form a combustion surface exposed on the outer side and an inner surface facing towards an inner side respectively, where the fabric forms an interlacing of metal wires having warp threads and weft threads transverse to the warp threads, and where both fabric surfaces form ribs in high relief alternating with valleys in low relief and that both the ribs and the valleys have an extension, in at least one direction in the plane of the fabric, greater than the space occupied by at least three consecutive warp threads in the weft direction and greater than the space occupied by at least three consecutive weft threads in the warp direction.

1 . A combustion membrane for a gas burner, comprising:
 an inner side to which a combustible gas is conveyed and an outer side on which combustion of the combustible gas occurs after it has crossed through the combustion membrane,   a fabric having two opposite fabric surfaces, which respectively form a combustion surface exposed on the outer side and an inner surface facing towards the inner side,   wherein the fabric forms an interlacing of metal wires comprising warp threads and weft threads transverse relative to the warp threads,   wherein both fabric surfaces form ribs in high relief alternating with valleys in low relief and that both the ribs and the valleys have an extension, in at least one direction in the plane of the fabric, greater than the space occupied by at least three consecutive warp threads in the weft direction and greater than the space occupied by at least three consecutive weft threads in the warp direction.   
     
     
         2 . A combustion membrane according to  claim 1 , wherein
 at the ribs at least one of the fabric surfaces forms one or more floats,   at the valleys at least one of the fabric surfaces forms areas free from floats or with floats shorter than the floats in the ribs of the same fabric surface.   
     
     
         3 . A combustion membrane according to  claim 1 , wherein the fabric has localized first areas with reduced gas permeability, alternated with localized second areas with higher gas permeability with respect to the first areas. 
     
     
         4 . A combustion membrane according to  claim 3 , wherein both the first areas and the second areas have an extension, in at least one direction in the plane of the fabric, greater than the space occupied by at least three consecutive warp threads in the weft direction and greater than the space occupied by at least three consecutive weft threads in the warp direction. 
     
     
         5 . A combustion membrane according to  claim 3 , wherein:
 in the first areas the fabric forms one or more floats,   in the second areas the fabric forms areas free from floats or with floats shorter than the floats in the first areas.   
     
     
         6 . A combustion membrane according to  claim 5 , wherein at the floats of the first areas the metal wires forming said floats are locally enlarged with respect to a width of the metal wires at the second areas. 
     
     
         7 . A combustion membrane according to  claim 1 , wherein the fabric forms a plurality of clusters of floats, said clusters being spaced apart from each other and distributed in two transverse directions in the plane of the fabric, each of said clusters comprising:
 on one of the fabric surfaces at least three or more parallel first floats, one directly next to the other,   on the other of the fabric surfaces at least two or more parallel second floats, one directly next to the other, the second floats being oriented transversely relative to the orientation of the first floats and superimposed on the first floats with at least six intersection points between the individual first floats and the individual second floats of the cluster,   between two consecutive clusters, respectively, the fabric forms extra-cluster areas free from floats.   
     
     
         8 . A combustion membrane according to  claim 3 , wherein the clusters form the first localized areas with reduced permeability and the extra-cluster areas form the second localized areas with higher permeability. 
     
     
         9 . A combustion membrane according to  claim 7 , wherein:
 the first floats of the cluster have a first central float and two first lateral floats on two opposite sides of the first central float and having a length shorter than the length of the first central float,   the second floats of the cluster have a second central float and two second lateral floats on two opposite sides of the second central float and having a length shorter than the length of the second central float,   the first floats are positioned and oriented mirror-symmetrical to the symmetry line formed by the second central float of the same cluster,   the second floats are positioned and oriented mirror-symmetrical to the symmetry line formed by the first central float of the same cluster.   
     
     
         10 . A combustion membrane according to  claim 7 , wherein:
 the first floats of the cluster all have the same length, but are positioned in a mutually staggered manner or in an alternating staggered manner,   the second floats of the cluster all have the same length but are positioned in a mutually staggered manner.   
     
     
         11 . A combustion membrane according to  claim 7 , wherein:
 the first floats of the cluster all have the same length but are positioned in a mutually staggered manner or an alternated staggered manner,   the second floats of the cluster have different lengths and are positioned symmetrically relative to asymmetry line formed by a first central float of the first floats of the cluster,   the fabric comprises a plurality of simple intersections of floats, said intersections comprising:   on one of the fabric surfaces exactly one primary float,   on the other of the fabric surfaces exactly one secondary float oriented transversely relative to the orientation of the primary float and superimposed on the primary float with exactly only one intersection point.   
     
     
         12 . A combustion membrane according to  claim 7 , wherein:
 the first floats of the cluster are arranged in a staggered step-like manner, defining as a whole a first strip which is oblique relative to the orientation of the individual first floats,   the second floats of the cluster are arranged in a staggered step-like manner defining as a whole a second strip oblique to the orientation of the single second floats and superimposed on the first oblique strip.   
     
     
         13 . A combustion membrane according to  claim 12 , wherein:
 in addition to the clusters which form first clusters, the fabric forms second clusters of a different shape and position than the first clusters,   the first floats of the second cluster are arranged to form a further first strip oblique relative to the orientation of the individual first floats but of a different shape from the shape of the first strip of the first cluster,   the second floats of the second cluster are arranged to form a further second strip oblique relative to the orientation of the individual second floats, but of a different shape from the shape of the second strip of the first cluster and superimposed on the further first oblique strip.   
     
     
         14 . A combustion membrane according to  claim 11 , wherein:
 the first clusters and/or second clusters are arranged to define a plurality of sequences of clusters extended in the weft or warp direction of the fabric in the form of strips oblique relative to the warp and weft directions.   
     
     
         15 . A combustion membrane according to  claim 7 , wherein, in the same cluster, the length of the longest float on the inner surface  20  is greater than the length of the longest float on the combustion surface. 
     
     
         16 . A combustion membrane according to  claim 1 , wherein:
 the fabric has a mass per area equal to or greater than 1.3 kg/m 2  or in the range from 1.3 kg/m 2  to 1.6 kg/m 2 ,   the metal wire is a yarn of mass per length in the range from 0.8 g/m to 1.4 g/m,   or in the range from 0.9 g/m to 1.1 g/m,   the metal wire is composed of fibers with diameters in the range from 30 micrometers to 50 micrometers or 40 micrometers.   
     
     
         17 . A combustion membrane according to  claim 1 , wherein the fabric is supported by and in contact with a support layer arranged on the inner side of the combustion membrane. 
     
     
         18 . A gas burner comprising a combustion membrane according to  claim 1 .