FR2738327A3 - Hyperstoichiometric mixing atmospheric gas burner - Google Patents

Abstract

The atmospheric gas burner is provided so that the mixture emerges from several primary slits (5) formed on the surface of the burner. These primary slits are generally disposed in one or more rows which run parallel to the axis of the burner. The auxiliary slits (4) are provided at intervals in the rows of primary slits. The auxiliary slits are situated parallel to the primary slits, and straddle two adjacent rows to extend between two adjacent primary slits. There are ancillary slits within a row of primary slits, disposed aligned with the auxiliary slits between two primary slits. The ratio of primary slits to auxiliary slits is between ten to one and four to one.

Description

The present invention relates to an atmospheric gas burner of the type

  said to hyperstechiometric mixture, of the kind in which the mixture exits through a series of slots made in the oaroi of the tubular body of the burner, which slots are arranged in one or more rows oriented parallel to the axis of the body. These burners, well known in practice, are capable of operating with a so-called hyperstechiometric combustion which makes it possible to obtain a

  drastic reduction of the emission of nitrogen oxides.

  In some of these known burners, cooling is provided.

  the wall which has the combustion slots. This cool-

  sement, for example obtained using water from the boiler associated with the burner, makes it possible to considerably reduce the content of

NOX from combustion products.

  In burners which do not have such cooling, it is really difficult to obtain modulation of the heating power since such adjustment can give rise to an increase in the temperature of the perforated wall of the burner body in provoking

  then dilations likely to determine perforations

of this wall.

  However, certain official regulations require the use of modulating burners, in particular in order to contribute to savings

of energy now in effect.

  Under these conditions, the present invention has set itself the aim of producing a burner of the aforementioned type which is able to avoid the drawbacks of thermal expansion, thus being capable of

  operate at temperatures significantly higher than those tolerated

  similar devices of the same kind.

  To this end, the invention mainly consists in providing, at regular intervals along the rows of combustion slots, auxiliary slots oriented parallel to the main slots in

  overlapping two contiguous rows thereof and extending sub-

  until reaching the midpoint of each of the two

affected rows.

  Tests have shown that these auxiliary slots play clean-

  ment the role of compensating members with regard to deformations which inevitably appear in the areas without slots in the wall of the body, that is to say in fact between two adjacent rows. The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing: FIG. 1 is a longitudinal section of an established burner

  in accordance with the present invention.

  Fig. 2 is the plan view from above.

  Fig. 3 is an end view of the same burner.

  Fig. 4, 5 and 6 illustrate in the same way another form

of achievement.

  Fig. 7 and 8 show on a larger scale the upper wall

  perforated lower burner according to either of the two forms of

envisaged realization.

  In either case, the burner is constituted by a body 1 of tubular shape. The combustible gas enters this body 1 through a nozzle (not shown) and mixes with the combustion air inside a Venturi 2 provided inside the body 1, below the upper wall 1 'of this one. In this wall 1 'is formed a series of slots 5 oriented parallel to each other in rows themselves oriented parallel to the axis of the body 1; there are two of these rows in fig. 1 to 3, three in the

case of fig. 4 to 6.

  It is at these slots 5 that the combustion of the mixture takes place which is brought into the upper part of the body 1 after having

  passed through a distributor 3 provided downstream of the Venturi 2.

  In accordance with the present invention and as particularly

  well illustrated in fig. 7 and 8, provision has been made in the wall 1 ′, at intervals

  regular valleys along the rows of slots 5, auxiliary slots 4 which are oriented parallel to the main slots 5 and which extend astride two contiguous rows until reaching the

  midpoint of each of these rows.

  These auxiliary slots 4 essentially function as organs

  compensation allowing thermal deformation of the burner body.

  In the manner shown in fig. 7 and 8, it is advantageous to provide secondary slots 6 in each of the rows of main slots 5, these secondary slots 6 being provided along the axis of the

  auxiliary slots 4. Such secondary slots 6 work identically

  main slots 5 and their purpose is to avoid any

  discontinuity in the flame from the burner in operation.

  It should also be understood that the above description has not

  given as an example and does not limit the area

  ne of the invention which we would not leave by replacing the details

  of execution described by all other equivalents.

Claims (2)

R E V E N D I C A T I ONS   1. Atmospheric gas burner of the so-called hyperstechio-mixture type   metric, of the kind in which the combustible mixture exits through a series of parallel slots (5) formed in the upper wall (1 ') of a tubular body (1) and arranged in at least two oriented rows   parallel to the axis of said body, characterized in that at intervals   the regulars along each of the rows, the wall (1 ') has auxiliary slots (4) which are oriented parallel to the latter   overlapping two adjoining rows that extend to reach   dre substantially the midpoint of each of these.   2. Burner according to claim 1, characterized in that the wall (1 ') has secondary slots (6) provided in each of   rows of main slots (5) aligned with the auxiliary slots binders (4).