FR2478266A1 - INFRARED RADIATION GAS BURNER RETURNS TO THE BASE - Google Patents

Abstract

A. BURNER WITH DOWNWARD RADIATION. B. CHARACTERIZED BY A METAL BODY 5 CONTAINING A VERTICAL VENTURI 2 TUBE WHOSE LOWER OPENING IS CLOSED BY A DOUBLE CYLINDRICAL SIEVE 13, 14, A SERIES OF PERFORATED SHEETS 8, 9, 10 FORMING A COMBUSTION CHAMBER COVERED AT THE TOP A THERMALLY INSULATING MATERIAL 12, WHICH IRRADIES THE HEAT BY RADIATION AND CONVECTION, DOWNWARDS, THROUGH A PERFORATED BOTTOM CLOSING SHEET 10. C. BURNER APPLICABLE TO HEATING THE ASPHALT SIDING IN ROAD CONSTRUCTION.

Description

i 2478266

  The invention relates to a gas burner, particularly

  adapted to the production of infrared radiation which is

returned to the base.

  It is known in road construction and maintenance engineering that paved pavement with a layer of asphalt must be softened by means of

  a large battery of burners that produce a

  infrared element sent down.

  The main disadvantages of the battery of

  br mounted on mobile supports, operating on the

  the interior, as is customary for the reheating of the pavement, with a forward speed of two or three meters per minute are the following: - possibility of lifting the bitumen,

  - significant temperature differences on the over-

face of the road,

  - interaction between the various burners of the bat-

  with the risk of rising gas inside them, - influence of climatic conditions and wind, - difficulty of maintaining a constant speed of advance, - frequent interruptions, due to the limited life of some burner organs subjected to high temperatures which cause

  dilation effects with permanent deformation

  nent. The present invention aims to achieve a

  burner for gas flame, for the production of infrared rays

  red, which is used to avoid the incon-

  mentioned above, and which produces a quantity

  important calories at high temperatures.

  The burner according to the invention is characterized

  in that it essentially comprises a metallic central body

  wherein a venturi tube is provided for mixing the fuel gas with the primary combustion air, said tube terminating at a lower outlet mouth having a double gate which opposes a return of the flame towards the inside of the burner, mouth which communicates with the

  closed combustion chamber, through horizontal slats

  Perforated plates with at least one intermediate strip which subdivides the flame so as to produce a uniform action without heat reflection towards the outlet mouth of the fuel mixture which may cause a return of the flame

  towards the inside of the Venturi tube.

  This results in a burner body that can withstand the bright red temperature producing rays

  infra-red which propagate downwards, normally over-

face to warm up.

  The description below relates to a mode of

  embodiment of the invention, given by way of non-limiting example

  tif, and explained with reference to the accompanying drawings in which: - Figure 1 is an axial vertical sectional view of the burner represented by half, the other half being symmetrical. FIG. 2 is a perspective view of the

  external grid for flame protection.

  FIG. 3 is a perspective view of the

internal grid.

  FIG. 4 is a perspective view of the double head flange whose function is to equalize the distribution

of the flame.

  As shown in Figure 1, the burner of the in-

  invention comprises an injector 1 for feeding the fuel

  a venturi tube 2 with an inlet mouth 3 for the primary combustion air, for its mixing with the combustible gas, an outer cover plate 4 connected to the cylindrical body 5 which supports the Venturi tube 2, and The body is connected to the bottom wall 6 and the flange 7. All these elements are made of a robust, heat-resistant metal sheet, for example of steel, or of non-metallic refractory material. They constitute the actual body of the burner. At the outer edge of the cover plate 4 are fixed by staples the perforated plates 8, 9

  and 10, advantageously by means of an annular retaining collar

11.

  The space between the upper outer cover plate 4 and the first perforated plate 8 is filled with a thermally insulating material 12 having a large

resistance to heat.

  On the flange, or lower counter-wall 7, is

  fixed a cylindrical sleeve 13 with fine mesh, externally

  metal sieve 14 with large mesh, possibly

  of perforated perforated sheet metal which is closed at its end.

  lower unit, by a coil 15, consisting of two parallel horizontal plates provided with holes of larger diameter in the upper plate, and lower in the lower plate, the whole is closed at the bottom by a

  grill cover 17 arranged downwards.

  The perforated intermediate plate 9 is suspended in the space between the two sheets 8 and 10 and is separated from the outer grid 14 by an annular space 16, which avoids direct contact between the sheet 9

and the grid 14.

  The fuel mixture passes through the grids

  13 and 14 outwards in the direction of the arrows 18, in

  radiated flame, which fills the space

  below the perforated plate 8, transmitting the heat down through the perforated plates 9 and 10, while upward the heat is transmitted to the material.

insulating filling 12.

  Advantageously, the perforated plates 8, 9 and 10 are made of heat resistant metal, being otherwise

  partly with annular ribs, in particular

  bind the lower plates 8 and 9 which must be the most robust. In particular, the inner plate 8 can be made by means of a thin sheet of steel which, even without perforation due to its reduced heat capacity, is

  rapidly heated to high temperature by the flame, and

  immediately puts the heat downward.

  An important feature is the presence of the transverse annular bore 16, which allows the intermediate perforated plate 9 to expand freely due to the large temperature variations, thereby eliminating the risk of heat transfer to the Venturi tube 2, which must

  stay cool during the operation of the br.

  Flame returns from the combustion chamber to the Venturi tube are avoided, thanks to the presence of the cylindrical sleeves 13 and 14, thanks to the conformation of the

  perforated grids 8, 9 and 10, which define the chamber of communication

  and therefore are raised to high temperatures during operation of the burner. The thermally insulating material 12 prevents the dispersion of heat towards the outer wall surface,

  above all, and opposes an inde-

  sirable heat that would be dangerous both for the

  only for the device itself.

  The perforated plates 8, 9 and 10 accumulate the

  temperature, and the heat is transmitted downwards, for example

  pavement pavement, primarily by irradiation

  tion, but also by convection, by means of the products of combustion coming out through the holes

of head 10.

  In summary, the main characteristics of the device according to the invention are as follows: a) The Venturi tube for mixing the combustible gas with the primary combustion air, cooled by the

passage of this mixture itself.

  b) The Venturi tube rises vertically and axially with symmetry with respect to the burner, so as to

form a symmetrical set.

  (c) The combustion chamber with horizontal direction

  in which at least one perforated metal sheet is provided

  mediate to make the flame more uniform.

  d) The double cylindrical sieve disposed at the outlet of the fuel mixture, which opposes any backfire of

  the combustion chamber towards the inside of the Venturi tube.

  c) The thermal invention above the combustion chamber that protects the upper and lower external environment

the Venturi tube.

  The use of a series of burners, carried out in accordance

  According to the invention, it is particularly advantageous to irradiate the heat downwards, for example in order to soften an asphalt coating, without exposing itself to the serious disadvantages which generally accompany the burners when they are returned with the flame directed towards the bottom. down, and without

  the individual burners interfere with one another when

that they are arranged in battery.

Claims (2)

A gas burner with infrared radiation turned downwards, characterized in that it comprises a metal body (5) in which is inserted a vertical axis Venturi tube (2) having a cylindrical exit head directed downwards with a wide lateral opening, closed by a double metal screen (13, 14) which opposes the return of the flame, a series of perforated sheets (8, 9, 10) extending horizontally forming a combustion chamber, covered at its upper part by a thermally insulating material (12), said chamber radiating above all its heat by radiation, but also by convection, downwards, through a lower perforated perforated sheet (10); ). Gas burner according to Claim 1, characterized in that the Venturi tube (2) in which the mixture of combustible gas and primary combustion air is produced has a vertical axis which constitutes an axis of symmetry. for the entire interior of the burner. Gas burner according to one of the claims   1 and 2, characterized in that, inside the combustion chamber, at the outlet of the mouth of the Venturi tube (2), and insulated upwards by a thickness of heat-insulating material (12), is inserted a perforated plate (9), horizontal,   sufficiently spaced from the outlet of the burner, protect   a pair of two cylindrical sieves (13 and 14)   to standardize the combustion of the flame in the combustion chamber, and to oppose the return of the flame in the Venturi tube.   ) Gas burner according to any one of   Claims 1 to 3, characterized by a pair of sleeves   cylindrical screens (13 and 14) arranged opposite the outlet mouth of the Venturi tube (2), allowing the mixture of combustible gas and primary combustion air to pass towards the combustion chamber but preventing a return flame   towards the inside of the Venturi tube.   ) Gas burner according to any one of   Claims 1 to 4, characterized by a large thickness   of thermally insulating material (12) disposed above the combustion chamber, opposing the upward transmission of heat, dangerous for personnel and equipment, of 6 2478266   the heat prevailing over the burner, and further opposing the heat transfer to the Venturi tube (2) which is kept cool by the passage of the fuel mixture to the during the operation of the br br.