AT391188B - DEVICE FOR DEDUSTING THE PRIMARY AIR FROM A PRE-MIXED GAS BURNER - Google Patents

Description

No. 391188

The present invention relates to a device for dedusting the primary air which flows to a premix gas burner, in particular a pilot burner, via a mixing tube

A gas burner has become known from GB-OS 2 090 961, in which a gas-air mixture is blown into a first chamber and is passed on to a settling chamber via a mixture line provided with a throttle point. The mixture undergoes an additional intensive mixing.

Contamination of a pilot gas burner arises on the one hand from the deposition of the dust on a gas sieve provided in the mixture guide and on the other hand through dust particles which penetrate this sieve or the gaps forming in its holder and settle in the mixture guide or on the burner nozzle.

The object of the present invention is to ensure that this problem is prevented by dedusting the primary air.

According to the invention it is proposed to achieve the object that a multiple deflection is provided in the flow path of the primary air to the inlet of the mixing tube. This multiple deflection enables dust to be separated in a simple manner and on account of the centrifugal force.

In an embodiment of the invention it is proposed that the multiple deflection is formed from a pipe socket, which surrounds the inlet area of the mixing tube at a distance and wherein a coil spring or labyrinthine baffles, e.g. B. ring flanges are arranged. This configuration results in a particularly simple arrangement, which is also particularly easy to replace for cleaning purposes due to the formation of an assembly.

In a further embodiment of the invention it is proposed that the multiple deflection be arranged in a calming chamber, the wall of which is closed by a removable cover. This makes it particularly easy to open the calming chamber and clean it.

Finally, it is particularly expedient that the ring flanges or the like baffles are arranged partly inwardly projecting on the cover, partly inwardly projecting on the outside of the mixture-guiding pipe emanating from the calming chamber. This configuration enables a particularly simple arrangement of the design of the baffles.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. In the drawings, FIGS. 1 to 4 each show a pilot gas burner in a side view or in a partial section through the pilot gas supply nozzle and a calming chamber arranged upstream of the inlet of the mixing tube.

The ignition gas nozzle (2) connected to the pilot gas supply line (1) opens into a mixing tube (4) in which very large openings are made which allow primary air to enter the mixing tube (4).

The pilot flame forms in the outlet (6) of the mixing tube (4). The mixing tube (4) is held together with a thermocouple (7) by a holder (8) on a gas burner (not shown) in a desired position with respect to its mixture outlet openings. The pilot gas nozzle (2) feeds the mixing tube (4) with gas and at the same time draws in primary air. Both components are mixed from the opening level (5) and passed through the mixing tube (4) to the outlet (6) of the pilot burner.

The primary air flows to the calming chamber (3) in the embodiment according to FIG. 1 via the annular gap (10), which is formed between the outside of the mixing tube (4) and the wall (9) of the calming chamber (3). If the primary air enters the chamber (3) via this throttling annular gap (10), its flow slows down and calms down within the chamber (3) and the substantially larger cross section of the inlet (5) of the mixture-guiding pipe (4). As a result of this slowdown, the dust particles contained in the primary air settle within the calming chamber (3) and can be removed from there temporarily during maintenance of the gas burner as soon as the wall (9) of the chamber (3) detachably attached to the holder (16) is released from this holder (16).

In the embodiment according to FIG. 2, instead of the annular gap (10), radial recesses (11) are provided in the wall (9) of the chamber (3), which serve the same purpose as the annular gap (10).

In the embodiment according to FIG. 3, a pipe socket (12) attached to the calming chamber (3) surrounds the inlet (5) of the mixing pipe (4) at a distance. A helical spring (13) is accommodated in the annular space (10), which forces the primary air flowing through to enter the calming chamber (3) in a circular motion. The centrifugal forces acting on the dust particles cause the dust particles to settle in this chamber (3), preferably at the bottom thereof.

In the embodiment according to FIG. 4, several deflections are provided for separating the dust particles in the primary air flow path, which are embodied by ring flanges (14) forming baffles. These ring flanges (14) are partially projecting outwards at the inlet (5) of the mixture-guiding pipe (4), partly projecting inwardly on a cover (15) which can be screwed onto the wall (9) of the chamber (3) and form a labyrinth for the primary air flow , in which the dust particles largely settle. The coil spring and the labyrinth form a multiple deflection (17).

All embodiments of the subject matter of the invention have in common that throttle elements determining the primary air throughput, that is to say for example the annular gap (10) or the recesses (11), are arranged at the beginning of the area of the primary air duct which serves for dedusting. On the other hand, the inlet (5) of the mixing tube (4) must be dimensioned as large as possible so that the primary air can be drawn in through the pilot gas nozzle (2) at a low flow rate in this area. To settle the dust particles -2-

Claims (4)

No. 391 188 also contributes significantly to the solution according to FIGS. 1 to 4 in that the initially downward-directed primary air flow within the calming chamber (3) is deflected when it enters the inlet (5) of the mixing tube (4). In the solution according to FIGS. 1 to 4, the fact that the initially downward-directed primary air flow inside the calming chamber (3) undergoes a deflection when it enters the inlet (5) of the mixing tube (4) also helps to settle the dust particles. 1. The device for dedusting the primary air, which flows into a premix gas burner, in particular pilot burner, via a mixing tube, characterized in that a multiple deflecting device (17) is provided in the flow path of the primary air to the inlet of the mixing tube (4). 2. Device according to claim 1, characterized in that the multiple deflection (17) is formed from a pipe socket (12) which surrounds the inlet region of the mixing tube (4) at a distance and in the annular space thus formed, a coil spring (13) or labyrinthine Baffles, for example ring flanges (14), are arranged. 3. Apparatus according to claim 1 or 2, characterized in that the multiple deflection device (17) is arranged in a calming chamber (3), the wall (9) of which is closed by a removable cover (15) (Figure 4). 4. The device according to claim 3, characterized in that the annular flanges (14) or the like baffles are partially inwardly projecting on the cover (15), partially outwardly projecting on the outside of the mixture chamber (3) outgoing mixture-guiding tube (4) are arranged ( Figure 4). Add 2 sheets of drawings -3-