DE2342398A1 - COMPRESSED AIR OPERATED ATOMIZED BURNER SYSTEM - Google Patents

Description

25 187

WALLACE W. VELIE
Upland, California (V. St. ", A.)

Compressed air operated atomizing burner system

There is growing interest in air powered atomizer burners because of these work with a very high combustion efficiency and with a very high level of cleanliness · in particular There is a growing interest in compressed air-operated atomizer burners, which also work with low Combustion speeds work properly · In these compressed air powered atomizer burners are generally a device for supplying the primary air to the compressed air operated atomizer nozzle, means for supplying fuel from a remotely located fuel source to the Fuel tank and means for supplying fuel from the fuel tank to the compressed air-operated one Nozzle, preferably in a properly controlled amount per unit of time, is required.

The object of the invention is therefore to provide a compressed air-operated burner system which fulfills the aforementioned requirements and works perfectly even at low combustion speeds.

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Another object of the invention is to provide a compressed air powered atomizer burner system, in which the means for supplying the primary air also for supplying fuel to the compressed air-operated The atomizer nozzle is used

It is also an object of the invention to provide a compressed air powered atomizer burner system in which the device for supplying primary air also serves to supply fuel to the fuel container from a remotely located fuel source.

It is also an object of the invention to provide a compressed air powered burner system in which the compressed air operated atomizer nozzle combined with a flame spreader to stabilize and shape the flame is.

It is also an object of the invention to provide a compressed air powered burner system in which the position and the diameter of the flame spreader are chosen so that optimum combustion is achieved.

Further objects and advantages of the invention emerge from the following description and the claims based on the attached drawings

The compressed air operated atomizing burner system according to the invention comprises an air compressor, a Fuel tank and a compressed air-powered atomizer nozzle The pressure side of the compressor is connected to the atomizer nozzle and to the fuel tank. the The suction side of the air compressor is alternately connected to the ambient air and to the fuel tank.

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In the suction line of the air compressor, a valve is arranged, which is the suction side of the air compressor during the combustion process with the ambient air and during the refilling process with the fuel container connects · The valve works depending on the fuel level in the fuel container · In a preferred embodiment will be for this purpose Solenoid valve used} which is controlled by a float switch, which is operated by means of an in the Fuel tank arranged float is operated mechanically ο

In the pressure line and the suction line connecting the air compressor to the fuel tank connect are throttling devices, e.g. B. Orifice plates arranged that the positive or negative pressure control the air in the fuel tank. Possibly is in the pressure line of the air compressor a device for regulating the pressure of the primary air supplied to the atomizing nozzle is provided.

The fuel container is connected to a remotely located fuel source. In the to that A non-return valve and a filter are arranged which have a refill line leading to the fuel tank Prevent backflow of fuel to the fuel source or filter the incoming fuel. The fuel container is also connected to the atomizing nozzle. The fuel supply line contains a Device for regulating the amount of fuel supplied, e.g. B. a throttle or an adjustable Throttle valve · The fuel supply line is also

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provided with a check valve that prevents a backflow of fuel to the fuel container · The Air-powered atomizing nozzle is a common type and uses compressed air to atomize fuel its burning.

The operation of the burner system is briefly described below. The suction line is during the combustion of the air compressor is connected to the ambient air. The air compressor sends primary air to the compressed air-driven atomizer nozzle so that the fuel is atomized into fine particles as it exits the nozzle opening. Secondary air becomes the compressed air-operated atomizer nozzle supplied in the usual manner, e.g. B. by natural suction. The air pressure in the The air compressor's pressure line is controlled by the air pressure regulator. Part of the compressed air in the pressure line of the air compressor is drawn off and returned to the fuel tank. The air pressure in the fuel tank is pushing Fuel from the fuel tank to the air powered one Atomizing nozzle. The amount of fuel fed to the nozzle is determined by the air pressure in the fuel tank and influenced by the throttle device in the fuel supply line.

If, after a predetermined operating time of the atomizer nozzle, the fuel level has reached a predetermined lower limit reached, the float in the fuel tank actuates the float switch so that the Solenoid valve connects the suction side of the air compressor to the fuel tank. Now fuel is from the remotely located fuel source via the refill line sucked in and the fuel tank refilled until the fuel level is a predetermined upper level Has reached the limit. At this point the

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Float the float switch in such a way that the solenoid valve the suction side of the air compressor reconnects with the ambient air and the combustion process is initiated again will.

According to a second feature of the invention is that
Compressed air operated atomizer nozzle combined with a flame spreader to stabilize and shape the flame. The position and diameter of the flame spreader are chosen so that optimum combustion is achieved and the accumulation of soot and carbon on the spreader is avoided. In general, it has been found that in most applications optimum combustion is achieved when the ratio of the The diameter of the flame spreader to the axial distance between the flame spreader and the compressed air-operated atomizer nozzle is approximately equal to 1.

In the drawings shows

Figure 1 shows the primary air and fuel supply system of the burner according to the invention and

2 shows the atomizer nozzle operated by compressed air and the flame spreader of the invention combined with the nozzle Burner

According to Fig. 1, the burner system includes a
Air compressor 10. This is of the usual type and consists, for. B. from a reciprocating membrane pressure
and suction pump and has three separate ones in the overall system
Tasks. Firstly, it leads primary air to the compressed air operated atomizing nozzle 1A for atomizing the fuel

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to. Second, it acts on the fuel container with air pressure so that fuel is fed to the nozzle. Third, the air compressor acts as a vacuum pump, when the fuel level in the container has reached a predetermined lower limit and the fuel container 12 is replenished from a remotely located fuel source 16.

The burner system also includes a fuel tank 12, also of conventional type. The fuel tank is sized to provide a suitable duration of combustion, e.g. B. from 10-15 min, and that, given the characteristics of the air compressor, it is quite fast, e.g. B. in 5-10 seconds, can be refilled. During the combustion process, the fuel container 12 is connected to the pressure side of the air compressor 10 and to the fuel inlet of the atomizer nozzle Ik.During refilling with fuel, the container 12 is connected to the suction side of the air compressor 10 and to the remotely located fuel source 16

The third main component of the burner system is the compressed air-operated atomizer nozzle Ik. This can be of any type and, for example, as shown in FIG. In the nozzle shown there, the air does not come into contact with the fuel until the fuel emerges from the nozzle outlet opening. But you can also use a nozzle in which the primary air is already in contact with the fuel

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before he leaves the nozzle. In this case, fuel is fed under a low pressure of e.g. B. 0.07 - 0.28 atm through an inner channel of the nozzle and primary air under a relatively low pressure of e.g. B. 0.07 - 1.05 atmospheric pressure passed through an outer channel · In any case, the air is used to remove the air from the nozzle outlet opening to atomize escaping fuel into small particles. The compressed air operated atomizer nozzle is preferably self-priming, i.e. This means that the secondary air is not pressed into the combustion zone, but rather when the system is in operation it is supplied to it by natural suction «

The pressure side of the air compressor 10 is through the compressed air line 18 with the atomizing nozzle l4 and through the compressed air line 20 with the fuel tank 12 connected. If necessary, you can regulate the pressure under which the primary air of the atomizer nozzle 14, provide an air pressure regulator. The air pressure regulator 22 is, for example from a pressure-regulating throttle which is connected upstream to the compressed air line 18 and downstream to the ambient air connected is.

The suction side of the compressor OK is alternately connected to the ambient air and to the fuel tank 12. A solenoid valve 2k is arranged in the suction line 26 and connects the suction side of the air compressor 10 with the ambient air during the combustion process and with the fuel container 12 during the refilling process. The illustrated valve 2.k is a two-way magnetic slide,

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however, other conventional valves can also be used. The valve 2k is connected to the suction line 26 through the air outlet line "^ k . It can be seen that the valve 2k in its normal, open position is connected to the ambient air through the air supply line 30. In the air supply line 30 there is a filter 32 for filtering the In the normal open position of the valve 2k , the electromagnet that controls it is de-energized. After the electromagnet is switched on, the valve 2k moves into its closed position in which the air supply line 3k is closed and the suction side of the air compressor 10 therefore with the fuel tank 12. The suction line 26 is connected here to the compressed air line 20, but can also be connected directly to the fuel container 12.

In the compressed air line 20 a throttle device 36 is arranged, which consists, for example, of a throttle orifice and throttles the flow of the air supplied to the fuel tank 12 by the compressed air line 18. The throttle device 36 should be as small as possible so that as much primary air as possible is supplied to the nozzle Ik , but it should be so large that the fuel container 12 is subjected to an air pressure that allows fuel to be fed to the nozzle Ik under the desired pressure and can effect in the desired amount.

In the suction line 26, a throttle direction is arranged, which here also consists of a throttle orifice and the flow of the fuel tank 12 to the air compressor 10 supplied air throttles. The throttle device

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should generally be as large as possible, so that the Fuel tank relatively quickly, e.g. B. in 5 - 10 seconds, should be refilled, but so small that the fuel container 12 can be pressurized with an air pressure, a supply of fuel to the nozzle effected under the desired pressure and in the desired amount.

The fuel tank 12 is through the refill line 40 with the remotely located Fuel source 16 connected, for example, an underground or above-ground fuel container · The refill line 4o contains a check valve 42 that only allows fuel to flow from fuel source 16 to fuel container 12 allows fuel to flow back on the other hand prevented from the fuel container 12 · The refill line 40 also contains a fuel filter to filter the fed fuel »You can use any liquid fuel, the usual is burned in compressed air operated atomizer burners, for example heating oil, especially heating oil No. or 2

The fuel container 12 is connected to the atomizer nozzle 14 through the fuel supply line 46 tied together. The fuel supply line 46 contains a throttle device 48 which is of any conventional type be and for example consist of a throttle or an adjustable throttle valve can. The throttle device 48 is dimensioned so

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that at the selected primary air pressure the fuel of the nozzle at the desired pressure and in the desired Amount is supplied. The fuel supply line 46 includes a check valve 50 that restricts a flow of fuel from the fuel container 12 to the atomizing nozzle 14 allows fuel to flow back to the fuel container prevented.

The servo-controlled solenoid valve 24 connects the suction side of the air compressor 10 during the combustion process with the ambient air and during the refilling process with the fuel container 12. The solenoid valve 24 is controlled by a float 52 and a float switch 54 · The weight and buoyancy of the float 52 are the functional properties of the float switch 54 adjusted so that the fuel level between switch actuations is considerable changes. This change is shown in FIG. 1 by the upper limit 56 and the lower limit 58 of the fuel level shown. The float switch 54, for example a snap switch, is closed by float 52 when the fuel level is reached reaches the lower limit 58, and is through the float 52 is only opened when the fuel level reaches the upper limit 56. By closing of the float switch 54 is the electromagnet of the Valve 24 switched on, so that the suction side of the air compressor IO with the fuel tank 12 is connected.

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The arrangement shown in Fig. 1 with the magnetic slide, the float switch and the float FIG. 10 illustrates just one example of an arrangement that can be used to alternate the air compressor 10 with the ambient air and the fuel tank 12 to connect. For example, you can get the same result with a Achieve valve that is operated directly by a float

The mode of operation of the burner system is described in more detail below: During the combustion process, the suction line 26 of the air compressor 10 is connected to the ambient air and the air compressor delivers primary air to the atomizer nozzle 14 via the compressed air line 18 The pressure regulator 22 regulates the pressure in the compressed air line 18 Part of the compressed air flowing in the compressed air line 18 is drawn off and fed to the fuel tank 12 via the compressed air line 26. At the beginning of the combustion process, the fuel level in the fuel container 12 is at the upper limit 56, the float 52 in its uppermost position and the float switch 5k open and connects the solenoid valve 24 on the suction side of the air compressor 10 to the ambient air. The air pressure in the fuel tank 12 now pushes the fuel through the supply line 46 into the atomizer nozzle Ik. The amount of fuel supplied is regulated by the throttle device 48. At the nozzle Ik , the fuel supplied via the supply line 46 is brought in by the primary air coming from the compressed air line l8 small particles atomized, ignited in the usual way and burned in the presence of secondary air

As the fuel burns at the atomizing nozzle 14, the fuel level in the fuel container will decrease 12 gradually down to the lower limit 58. If the fuel level reaches this lower limit, the float 52 closes the float switch 54, so that the The solenoid of the valve 24 is switched on and the suction side of the air compressor 10 with the fuel container · At a given suction pressure of the air compressor, the negative pressure is in the fuel tank 12 depends on the diameter ratio between the orifices 38 and 36 · During During the refilling process, fuel is fed from the fuel source 16 via the refill line 40 into the fuel container 12 sucked and filtered through the filter 44. When the fuel level is in the fuel tank 12 reaches the upper limit 56, the float 52 opens the float switch 54, which is now the The solenoid of the valve 24 turns off, so that the suction side of the air compressor 10 again with the ambient air connected and the combustion process is re-initiated.

The present compressed air-operated atomizer burner system can be used with particular advantage when combustion of less than 1.9 l / h is required, e.g. B ₀ for hot water heaters. For example, one can work with the burner system according to the invention with a combustion rate in the range of 0.76-1.7 l / h if one chooses a primary air pressure of about 0.56-1.27 atmospheres. The air pressure in the fuel tank 12 is determined by the choice of the throttle devices 36 and 38

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limit to a maximum of about 0.11 atm when the diameter ratio of the orifice 38 to the Throttle orifice 36 is about 1.75. By increasing this diameter ratio, the Air pressure in the fuel tank 12 is reduced »At a fixed diameter ratio between the amount of fuel supplied to the atomizer nozzle 14 takes the throttle orifices as the primary air pressure decreases ab influence·

Another feature of the invention will now be explained. FIG. 2 shows the combination according to the invention a compressed air operated atomizer nozzle with a flame spreader. The combination shown in Figure 2 a compressed air operated atomizer nozzle and a flame spreader is particularly advantageous in the compressed air-operated atomizer burner system shown in FIG usable and is therefore described as part of this system. It is understood, however, that the invention Combination of the compressed air operated atomizer nozzle and the flame spreader also together with other systems for the supply of primary air and des Fuel Can Be Used · The air powered atomizing nozzle 14 is of a conventional type a nozzle head 60 with an air outlet opening 62. The nozzle head 60 is surrounded by a fuel pot 64, the is open to the atmosphere and a spray of fuel from the atomizer nozzle 46 · The fuel pot is charged with fuel via the fuel supply line 46 * The fuel level in the fuel pot 64 is kept so high during the combustion process, that above the nozzle head 60 and the air outlet opening 62 there is a thin film of fuel · Through

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the compressed air line 18 is charged, the nozzle head 60 Rait compressed air * In connection with this feature of the invention, it is desirable if the spray nozzle Ik a spray cone with a relatively small cone angle of z. B. generated about 30.

The flame spreader 66 has the usual shape for gas burners and can be made of any conventional material made of stainless steel or ceramic, for example. The flame spreader 66 is general disk-shaped and has a flat or convex surface on which the flame hits «Die Form und der However, the material of the flame spreader 66 does not constitute part of the present invention ο It has been shown that that the flame spreader can be used with particular advantage in burner systems which have a low combustion rate work in the range of 0-1.9 l / h

You can use the flame spreader 66 of the

Assign compressed air-operated atomizer nozzle Ik in the usual way. According to FIG. 2, the atomizer nozzle Ik is carried by a support body 68. Vertical supports 70, which are connected to a support ring 72, are attached to the support body 68. This carries a flame guide 74. The flame spreader 66 is held by supports 76 which are fastened to the flame guide 7k. An ignition device 78 of the usual type, for example a high-voltage spark ignition device, is attached to the support body 68.

During operation, the primary air expands through the air outlet opening 62 of the nozzle head 60 and atomizes

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doing the fuel in fine particles. These fine particles are mixed with secondary air entering through natural suction between the supports 70 in the system · The atomized fuel is ignited by the igniter 78 The flame thus formed is supplied to the flame spreader 66 by means of the flame guide Jk. The flame is stabilized and shaped at the flame spreader 66, the upper surface of the flame guide 7k acting as a radiation shield.

The flame spreader 66 should be arranged at right angles to the axis of the compressed air-operated atomizer nozzle 14 and approximately centered with respect to the nozzle (with a tolerance of about 6.4 mm) In order to obtain optimum combustion, the flame spreader 66 should be in the gaseous or hydrolyl combustion zone This zone is located downstream of the droplet evaporation zone and upstream of the yellow zone of the flame or carbon combustion zone.If the flame spreader 66 is located too far in the droplet evaporation zone, substances will be deposited on it which are caused by the evaporation of the liquid and If the flame spreader 66 is too large or too far in the yellow zone of the flame or carbon burning zone, however, carbon will accumulate on the surface of the flame spreader ·

Since the length of the flame also increases with the amount of fuel sprayed, the flame spreader 66 must be further removed from the atomizer nozzle Ik when this amount is increased. For example, it has been shown that

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Sufficient combustion is achieved when the axial distance (X) between the nozzle head 60 and the Flame spreader 66 at low burn rates from about 0.19-1 »9 l / h is about 38-127 mm. In most cases it has been found that optimum combustion is obtained when the ratio the diameter (D) of the flame spreader to the Axial distance (X) is about 1. The arrangement of the ignition device 78 is not critical; however, it should be in the most cases at the edge of the spray cone and about 19 - 38 mm downstream of the atomizing nozzle.

The compressed air operated atomizing burner system shown in FIG. 1 was used together with the combination of a compressed air operated atomizing nozzle and a flame spreader shown in FIG the flame spreader 66 89 mm. The flame spreader 66 was made of ceramic and had the usual shape of a disk with a flat surface on which the flame impinged. The flame spreader was arranged at right angles to the axis of the atomizer nozzle 14 so that the center of the flame spreader was at most 6.4 now from the center line of the spray cone emitted by the atomizer nozzle 14. The air outlet opening 62 of the atomizer nozzle 14 had a diameter of 0.46 mm. The air pressure generated by the air compressor 10 in the compressed air line 18 was during the combustion process a 1.05 ^u * and atu during the refilling 0.07. The diameter of the orifice plate 36 was 0.51 mm and that of the

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Throttle orifice 38 0.76 now * The pressure in the suction line 26 was 0 atm during the combustion process and - 0.7 atm during the refilling process. The air pressure in the compressed air line 20 was 0.11 atm during the combustion process and -0.7 atm during the refilling process. Of the The pressure in the fuel container 12 during the combustion process was 0.11 atmospheres and caused a discharge of Fuel via line 46 to the compressed air operated atomizer nozzle 14. The combustion rate was 1.36 l / h fuel. The system was operated trouble-free for 420 hours, with the combustion process in each case Lasted 10 minutes and then interrupted for 10 seconds each time. This control was through the float 52, the float switch 54 and the solenoid valve 24 carried out automatically.

The invention is not limited to details of the illustrated and described exemplary embodiment within the scope of the inventive concept and while respecting the most important Advantages of the subject invention can be modified.

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Claims (1)

Claims t Compressed air operated atomizing burner system, characterized by a compressed air operated atomizing nozzle for atomizing liquid fuel with the aid of compressed air, an air compressor, a device for supplying of compressed air from the pressure compressor to the atomizing nozzle, a fuel container for receiving liquid fuel, a device for supplying liquid fuel from a remote location Fuel source to the fuel container, a device for supplying liquid fuel from the fuel container to the atomizing nozzle, means for supplying part of the from the air compressor discharged compressed air to the fuel tank and means for connecting the suction side of the air compressor with the ambient air during a combustion process carried out on the compressed air-operated atomizer nozzle and with the fuel container while refilling the fuel container 2. Atomizer burner system according to claim 1, characterized in that the means for feeding a portion of the compressed air delivered by the air compressor to the fuel tank, a throttle device for throttling the flow of the compressed air supplied to the fuel tank. 3. atomizer burner system according to claim 1, characterized in that the means for feeding of liquid fuel from the fuel container to the compressed air operated atomizer nozzle, a throttle device for restricting the flow of fuel to the atomizing nozzle. 409809/0566 4o atomizer burner system according to claim 3, characterized in that the throttle device is off a throttle orifice. 5 · Atomizer burner system according to claim 1, characterized in that the device for connecting the suction side of the air compressor with the fuel tank a throttle device for throttling the flow of the air drawn in from the fuel container contains 6 · Atomizer burner system according to claim 1, characterized in that the device for connecting the suction side of the air compressor with the fuel container one of the fuel level in the fuel container dependent device and a servo-operated valve by means of this device 7 · Atomizer burner system according to claim 6, characterized in that the fuel level in the fuel container responsive device has a float and a switch mechanically operated by this having· 8. atomizer burner system according to claim 1, characterized in that the means for supplying compressed air from the air compressor to the atomizing nozzle has a device for regulating the pressure of the compressed air supplied to the atomizing nozzle 9 · Compressed air operated atomizing burner system, characterized by a compressed air operated atomizing nozzle for atomizing liquid fuel with the help of A O 9 8 C 9 / O 5 6 6 Compressed air, a device for supplying compressed air to the atomizing nozzle, means for supplying liquid fuel to the atomizing nozzle, a Device for igniting the liquid fuel in the presence of combustion air to form a Combustion flame and one downstream of the Ignition device arranged flame spreader to stabilize and shape the flame 10. atomizer burner system according to claim 9, characterized in that the ratio of the diameter of the flame spreader to the distance between the flame spreader and the atomizer nozzle is approximately 1. 11. Atomizer burner system according to claim 9 » characterized in that the flame spreader in the gaseous or hydrolyl combustion zone the combustion flame is arranged » 12. atomizer burner system according to claim 9 »characterized in that the arrangement of the flame spreader relative to the atomizing nozzle with the burn rate of the fuel is related. 13 «atomizer burner system according to claim 12, characterized in that the flame spreader at a higher Combustion rate is arranged further downstream from the atomizing nozzle. 409809/0566 l4. Atomizer burner system according to claim 9 »characterized in that the flame spreader 38 is arranged 127 mm downstream of the atomizer nozzle. 98 0 9/0566