DE2362815A1 - BURNER FAN - Google Patents

Description

DlPL-ING. GRAMKOW DR. MÜLLER-BORE

DlPL-PHYS. DR. MANITZ DIPL-OHEM, DR. DEUFEL DIPL-ING. DARK FOREST

PATENT LAWYERS
7 STUTTGART 50 (BAD CANNSTATT) SEELBERGSTRASSE 23/25 December 12, 1975

Gr / Bt 5/5

Applicant:

Soclete pour 1'installation du Chauffage Automatique (S.I.C.M.A), 55, rue Danton, 923ΟΟ Levallois Perret / France

"Burner fan"

The invention relates to a burner fan with a housing, an action turbine, which is in an approximately cylindrical Chamber in the form of a spiral or volute with forced circulation of a sucked air stream in Hotati on is displaced and in or on a side wall of the having an inlet opening to said chamber Housing is arranged, as well as with a conveyor suction channel, which opens tangentially into the chamber and to the "burner head of the burner.

Most burners designed for smaller heating systems or medium power are provided, consist essentially of a piece of pipe that is in the grate of the Furnace opens, a combustion head at the entrance of the pipe section with injection of fuel under pressure and a fan with turbine to supply the fuel with air.

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Most frequently, fans of the type mentioned are used. In the heating systems that use a burner of the aforementioned type, there are often considerable pressure disturbances, especially during the ignition process, at the level of the burner head, these disturbances being characterized by an unstable flame area reproduced and produced a characteristic sounding beating (BF) that was very difficult to calm down is.

These pressure disturbances in the grate are mainly noticeable in the combustion, but mainly in the Ignition by a very short pressure peak, but a relatively strong intensity peak, for example of the order of magnitude of 80 mm water column. In general, such a pressure peak results from dynamic charging losses, which arise at the outlet of the pipe section in the formation of the furnace gas circuit, where you can get around the To reduce interference, trying to get maximum heat exchange by reducing the speed and the turbulence of the combustion gases increases.

This creates pressure waves, which tend to affect the flow of air at the level of the burner head to oppose. However, with fans of the type mentioned above, the increase in air pressure at the outlet of the remains Fan very weak, not to say zero,

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when the fan output tends to zero. So it was necessary to back up the flame in to avoid the burner, to provide a strong charge loss (perte de charge) especially at the burner head, while on the other hand the loss of charge when sucking in the Fan must be weak enough to ensure the necessary air output when the burner is working properly .

Nonetheless, causing a strong Loss of charge at the burner head of the burner has the appearance of a large flame velocity and, accordingly, one rushing work of the burner. Moreover, this loss of charge does not allow a good damping of the pressure wave to achieve and due to this causes the above-mentioned sounding flames (BF) as soon as the ignition comes into operation.

Understandably, one could think of reducing such a charge loss in an attempt to remedy this disadvantage to fix. However, such a reduction makes it necessary to reduce the charge loss in the opposite sense Suction of the fan to intensify what again when If you look at the power / pressure curves of this type of fan, the air pressure at the outlet of the latter is based on a power Zero or very poor performance decreased.

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As a result, such a solution is not possible when working in the area of fans with weak Disorder wants to remain.

Another solution to the problem of limiting flame noise and regulating work; is to use fans equipped with so-called reaction turbines, their Blades have a concavity facing the rotation of the turbine. With such fans it is possible to effectively obtain a substantial outlet air pressure for zero performance, but on the condition that that the turbine is given a very high peripheral speed. However, this condition requires its use of turbines of very large dimensions and high peripheral speed, which means great effort and increase in the manufacturing price means. In practice, such fans with reaction turbines are only used in industrial applications Used equipment of great strength.

The invention proposes to use a fan equipped with a simple action turbine, to ensure that the burner head is working properly. Such a fan only needs one relatively weak force and holds within the framework of a relatively low effort. Accordingly, the inventive Fan characterized in that it has a passage for a Wiai swirl through which a part

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the air conveyed through the turbine back into the turbine is injected in such a way that the dynamic energy of the air mass re-swirled in this way is normally The energy supplied by the turbine is amplified accordingly.

Such re-turbulence makes it possible to control the flow rate and accordingly also the air pressure at the outlet of the fan despite the reduction in fan output to keep as high a value as possible, i.e. a sharply decreasing power / pressure curve at maximum and practical constant air pressure and zero power, whatever the change in charge loss in the intake line of the fan.

Based on such a power / pressure curve for the air flow conveyed through the burner head of the burner it becomes possible that a relatively small charge loss is obtained if, as explained above, the relatively significant load loss caused when the fan is sucked in, with practically no effect on the size of the Air pressure at the power is zero. You can see the good work of the burner head in spite of the strong Ensure pressure disturbances on the grate caused by the flame during combustion and mainly during the ignition process be evoked. The size of the disturbances remains "below the pressure value at power zero

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of the fan, so that the flashback of the flame under the effect of the pressure wave and the accompanying noisy turbulence thanks to the weak charge loss of the Burner head is avoided and dampened quickly.

According to a preferred embodiment of the invention The ventilator is the front chamber wall, which contains the confluence of the intake duct, to a certain extent Arranged at a distance from the inlet opening of the turbine. This creates the passage for the aforementioned re-turbulence on the one hand together with a neck ring firmly connected to the housing and surrounding the suction channel and on the other hand formed together with a locking plate interposed between said front wall and the turbine is arranged in the area of a projection or beak, which in turn passes through the opening of the suction channel in said chamber is formed. The outer diameter of the free annular edge of the neck ring is here smaller than the diameter of the inlet opening of the turbine, so that part of the air flow that is near the neck ring circulates between said front wall and the turbine, into the inlet opening of the latter at the beginning the spiral is returned in front of the locking plate.

Preferably, the hairing can be annular on its outer Flushes exposed to the air flow circulating in the chamber are frustoconical

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so that part of the air flow is returned to the inlet opening of the turbine at a certain angle is, wherein the neck ring is preferably arranged eccentrically with respect to the turbine axis, around the To increase the cross section of the re-swirl passage of the turbine accordingly.

For a better understanding, the invention is described with reference to the following drawing, which is only an example represents an embodiment of the invention. Show in detail

Fig. 1 is a perspective view of a burner according to the invention with partially disassembled Share,

FIG. 2 is a schematic cross section, seen from the drive side of the burner valve fan of FIG. 1,

Fig · Ί> a section along line 1II-III of Fig. 2 and

4 shows a comparative representation for various Loss of charge during suction, namely power or pressure curves during use or after use of a fan according to the invention.

In Fig. 1, 10 denotes a burner for liquid or gaseous fuel, which is a (not shown) boiler for a heating system of medium strength is intended to be delivered.

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The burner 10 consists in herkömmlichei ¹ species in eljiem. Burning head 12 ,. the one at the entry of a pipe section _? l4. ahge _r . · is arranged, and a turbine fan 16 rttr the. Supply of the combustion head 12 with air.

In the form shown, the combustion head is centered in the housing 22 of the fan 1β by means of a customary broad-point suspension at the end of the suction channel 20. This housing is preferably designed with two symmetrical walls and designed so that it can be attached to the pipe section 14 on the (not shown) slab support plate of the boiler by means of angled attachment (not shown) and with the interposition of an insulating compound made of asbestos 24 , ■ that the pipe section 14 is not in därges deriva- (allocated j rest of the vessel extends a certain distance.

The burner head 12 essentially has a nozzle (not shown) which is supplied with fuel through a delivery pipe 26 ^ two electrodes 28, which are mounted on an insulating support 29. High voltage transformer to be connected; and an annular Stäbilisätiöhsäggregät on which a ring 50 and an annular disc t ^ 2 tr%, the expedient in the axis of the Breiinfcopfes by a Drelpurikt-centering 34 is gehal-- _r th.

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The stabilization unit -30 to j52 is designed in such a way that it allows the control of the charge loss (perte de charge) at the combustion head 12 of the suction channel 20 to the pipe section 14. ^:

The supply pipe ~ 2β penetrates the housing 22 for the purpose Connection to an external supply line 44 by means of a Connection 36, which in the usual way on a controllable Unit of two end plates 38 and 40 attached which is screwed onto an opening 42 of the housing 22 are. The latter is powered by a pressurized fuel suitable (not shown) fuel pump with interposition a (not shown) regulating locking device, which supplies the from the pump to the nozzle of the burner head 12 regulates the amount of fuel delivered. Such a regulating device generally works in systems with a lower output on full or nothing.

The fan 16 consists of a turbine 46, which on the output shaft 48 of an electric motor 50 is mounted and is set in rotation by this. Can be beneficial the engine, moreover, also has the above-mentioned fuel pump drive.

The '46 turbine is designed to rotate freely in a cylindrical Chamber arranged in the "form" of a spiral or volute 52, which between the two end walls of the housing 22

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is formed in such a way that a strong circulation of the air flow is caused during rotation, namely at the frontal inlet opening 54 which is formed on one of the side walls of the housing to the above-mentioned suction channel 20. This opens tangentially into the aforementioned spiral chamber 52 by means of a funnel-shaped intermediate ^; Piece 56 a. A neck ring 58, the particular shape and object is described below in conjunction with FIGS. 2 and J> is the housing 22 is fixedly connected to the edges of the front opening 54 by writing to this by means of a set screw 60 together with a cylindrical pipe piece 62 is attached> which forms a suction pipe piece opening into the opening 71 of the neck ring 58.

The line 64 is provided with a conventional control device 66 , which allows the charge loss to be changed when the turbine is sucked in. According to the embodiment shown, the regulating device 66 consists of a wing 68, which is pivotably mounted on an axis 70 diametrically penetrating the pipe section 62 and is connected to a conventional manual operation ^{:. r} ■ '* · ^l -'"' ^;

The through line 64 and the central opening 71 The suction line formed by the neck ring 58 opens into the chamber 52 in front of the inlet opening 72 of the turbine 46, so that it ends at the blades 74 of the latter. The turbine is of the so-called action type, in which the concavity of the blades 74 is rotated in the direction of rotation of the turbine.

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that ate axial, Lj ^^.

§Piräie _: Bä bigger, -is alip; ^ the ,, g ^ ial · ^ fear, _t the ^ turbine: and that last ^ ztere iin üBrig-eii ip _; riä] ^ like ^ glicft ^ p the ,, front wall desiOjeh ^ uses 2ä _b arranged; 1st, weieiieypii d ^ r iielie 48 desl on. dXe ^ ir Waiid Be fortified gh Uo.% qr &. 50, ' äurcMä # tzt; _: wif'd ,. It results in a 4äratis ^ öii. End wall 7,5 d # r Känimer _52: #eipiiera in the KnsäügeX & itüng, -0 ^ - einmühäetj Jl ^1, a certain axialen.Abstand, νρϊΐ dei Eini ^ ittsÖffrtüng 72 / turbine 46 has Därübör fiihäüs ^ ye extended dfr collar - 58 the K.äriai 64. against the Käftiniei 52 zii; in order to let the seri ^ as-close as possible aia the entrance opening 72 of the Turbiriö 46 flow out.

_; ih- Fig. 2 därgeÄtelit; .is, the ^ flaisrlhg ^ 8, related. on you, axis, x- of the turbine offset eccentrically, with the outside dürciMeäsör _; of the ring-shaped free. Edge 7 $ of the neck ring 58 kleiji ^ r äjLö the one. Who;. Entrance fee 72 is such that an essential jet 1 S./äleaerr^ffhüng pdt _: dei.Jammer 5,2 communicates in the dömjehlgen part of the latter, -, an which the formation of the spiral (volute) begins.

In addition, the annular outer surface 78 of the neck ring 58, which is exposed to the air flow inside the chamber: 52. zirinillerihd'eri - ". Is frustoconical in shape with a certain conical vortex. Finally, the free sand 76'des Neck ring -V · .--; ■.: ■ =: ^ -. ■ · ■ ::, ■ · / ■ ·;.: -V · "ORIGINAL INSPECTED

4ÖS828L / Ö2.91. ......

provided with an annular rim 8o which extends radially inward. Such a board increases, as can easily be seen, the loss of charge of the through the conduit 64 and the central opening 71 of the neck ring formed access channel.

The fan according to the invention is provided with a blocking plate 82 which is located between the end wall 75 and the turbine 46 is arranged, to the side of the nose-like projection 84, which forms the opening of the suction channel 20-56 into the chamber 52.

The blocking plate 82 thus forms the downstream end of a vortex channel which is formed around the neck ring 58 between the front wall 75 of the chamber 52 and the inlet opening 72 of the turbine 46. If one takes into account the position of the opening of this vortex canal in the inlet opening 72 and to the surface S of this mouth on the one hand and at the same time the frustoconical surface of the neck ring 58 on the other hand, it is understandable that such a vortex canal allows part of the flow through the turbine into the chamber 52 entering air again into the turbine 46, the blowing in of the air mass swirled in this way takes place according to a process according to which the energy of this air mass is added to that energy which is normally supplied by the turbine _{or the like}

■■ 3 I

With such a method of operation, it will be understood that it is possible to keep the flow velocity Vg of the individual air flows with respect to the turbine at the highest possible value, namely, at the inlet of the suction opening, from which the resulting suction velocity Vg, which is derived from this flow velocity V “And the circumferential speed V _{c of} the turbine results (see FIG. 3) * just as the output of the fan is reduced.

The power / pressure curves that are obtained by the fan according to the invention for various values of the charge loss in the intake line are shown with B- ^ B ₂ and B, in FIG. Likewise, in this figure with A ₁ , Ap and Α- the curves power / pressure are shown, which are achieved with a conventional fan with the same suction charge losses.

The examination of the curves B shows that a reduction in the power, which results for example from the cover of the suction channel 20 or as a result of a stronger pressure wave immediately downstream of the burner head 12, results in a strong increase in the air pressure in the suction line, with the pressure on Maximum P _{Q reached} at zero power.

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It appears that this pressure P _{Q is} independent of the size of the intake / charge loss of the fan, so that it is possible, by modifying this charge loss, to adapt the performance of the fan to the puncture of the burner use without the additional advantage of increased air pressure during intake to lose.

In addition to this possibility, I add the further, in respect on the burner head of the burner a relatively weak charge loss with the in the introduction of the present application to achieve the advantages explained. Indeed, the high value of the air pressure results in zero power in itself a pushing back of the flame in the burner head with all the disadvantages that result from the fact that, under certain circumstances, downstream of the latter a pressure wave, in particular from the ignition process, emanates, and this despite a loss of charge on Combustion head, which can be kept relatively weak at will, in order to dampen the possible pressure vortex to allow.

It should also be noted that the essence of the modification of the power / pressure curves B of a fan according to the invention is obtained thanks to the vortex canal that surrounds the neck ring 58 formed between the wall 75 and the turbine 46 and is limited by the blocking plate 82, which maintains the maximum pressure in the region of the beak 84. the

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Eccentricity of the neck ring 58 with respect to the turbine 46 and the frustoconical shape of its annular outer surface 78 allows it by the Area S of the re-entanglement cross-section is enlarged and the entangled stream filaments in a suitable manner the turbine is oriented towards improving the results obtained thanks to such re-fluidization.

The bent edge 80 of the neck ring 58 has substantially the purpose of an additional charge loss when sucking in the fan, as explained above was to bring about. This allows, albeit to a lesser extent, the results obtained thanks to the above Features to be further improved.

On the other hand, also for the same purpose, the formation of the spiral chamber 52 has one first sector, from the beak 84 at a constant, relatively gentle slope up to approximately a point Y. which runs the spiral, as well as a second sector that runs from this point Y extends to the mouth of the intake channel 20-56 and its slope is progressive grows. The first sector ensures the re-entangling performance and the overloading of the second sector, which in turn allows the increased suction pressure level.

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Of course, the invention is not limited to the embodiment described and illustrated. Numerous modifications, in particular with regard to the shape of the suction channel 20-56, the arrangement of the combustion head 12 in this channel, the shape of the neck ring and the construction of the device 66 for regulating the suction / charge loss can be made without the core of the To leave the invention characterized claims.

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Claims (1)

Expectations: (l-Λ burner fan unit with a housing, a Action turbine in an approximately cylindrical chamber in the form of a spiral or volute when forced Circulation of a sucked air stream is set in rotation and in or on a side wall having an inlet opening to said chamber of the housing is arranged, as well as with a conveyor suction channel which opens tangentially into the chamber and leads to the combustion head of the burner, characterized by a re-fluidization passage through which a part the air conveyed by the turbine is blown back into the turbine in such a way that the dynamic Energy of the air mass re-whirled in this way amplifies the energy normally supplied by the turbine accordingly. 2. Fan according to claim 1, characterized in that the wall of the chamber into which the suction channel opens, has a certain distance from the inlet opening of the turbine, wherein the re-swirl passage is formed in that it is on the one hand connected to a fixedly connected to the housing, the intake duct surrounding neck ring and on the other hand with a locking plate, which between said wall and 409828/0291 of the turbine in the area of a beak-like projection cooperates, which is formed by the opening of the suction channel in said chamber, and that the outer diameter of the free annular edge of the neck ring is smaller than the diameter of the inlet opening of the turbine is such that part of the circulating in the vicinity of the neck ring Air flow between said wall and the turbine again in the inlet opening of the latter accordingly the formation of the spiral or volute can be blown in again in front of the locking plate. J5. Fan according to claim 2, characterized in that the annular outer surface of the neck ring is frustoconical Has shape and is exposed to the circulating flow in the chamber such that part of the Air flow is blown back into the inlet opening of the turbine at a certain angle. 4. Fan according to claim 2 or ~ 5, characterized in that the neck ring with respect to the axis of the turbine is arranged eccentrically from the re-entanglement, such that the / cross-section formed zone of re-injection into the inlet opening of the turbine is enlarged. 4098 28/02 91 5. Fan according to one of claims 2 to 4, characterized characterized in that the free edge of the neck ring is provided with an annular rim, which extends radially inward to increase the charge loss of the suction port. 6. Fan according to one of claims 1 to 5> characterized in that the course of the spiral wall of the chamber consists of a first sector with a constant relatively weak slope and a second sector, the slope of which increases progressively. 409828/02 9 1 Blank page