JPS6039922B2 - How to prevent lift in gas burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing flame lift in a gas burner, which utilizes the action of an electric field applied to a flame to prevent flame lifting and misfire, thereby enabling stable combustion.

Generally, fuel gas or a mixed gas of fuel gas and air is used in a gas burner (hereinafter simply referred to as a burner).

) When the gas is ejected from a burner boat to generate fuel, if the ejection speed of the gas exceeds a certain limit, the flame will be released from the burner boat and cause so-called lifting, and in severe cases, a misfire will occur. Now, as a flame stabilization method, a method is conventionally known in which positive and negative electrodes are provided in the flame, and a high box pressure is applied to the electrodes to cause a discharge to give energy to the flame, thereby stabilizing the flame. However, in this case, the characteristic is that dielectric breakdown occurs between the two poles, and the resulting spark increases the temperature of the flame itself and accelerates the fuel flow. Not only does this require a high voltage and increase the dielectric strength of the equipment, but it also has drawbacks such as inducing gas explosions due to discharge and electric shock to humans.

Note that in a flame rod type flame monitoring device, a technique is known in which a rod is placed in the flame and a voltage of around 200 V AC is applied to the rod, but this only detects the presence of a flame. This type of flame detector uses the difference in ion distribution between the inner and outer flames as well as the difference in the ion absorption state due to the difference in electrode shape to give a rectifying effect to the flame. The voltage is applied to the flame, so the limiting condition is that the monitoring electrode be located within the outer flame of the flame.

The present invention provides a flame lift that prevents flame lifting and misfires and stabilizes the flame by simply applying a DC or AC voltage between the flame and the burner base within a range that does not cause dielectric breakdown. This provides a method of prevention.

That is, the applicant proposes a DC voltage of 2000 V or less or 300 to 2000 V that does not cause gas dielectric breakdown between the electrode inserted at any position within the flame and the burner base.
It was discovered that by applying an alternating current voltage of V, it was possible to very effectively forcefully hold the lifting surface of the flame within the burner base and prevent the lifting phenomenon of the flame.
This fact was confirmed through experiments.

It has been found that, especially in a continuous flame produced by a multi-hole burner, by applying such a voltage to a part of the flame, the lifting phenomenon of the entire continuous flame can be prevented. The present invention is based on this discovery and provides a method for stabilizing or preventing lift of a flame generated from a gas burner. Next, an embodiment of the present invention using a DC power source will be described with reference to the drawings.

First, the structure will be explained with reference to Fig. 1. In the figure, 1 is the base of the gas burner (hereinafter simply referred to as the base), 2 is the flame hole of the base, 3 is the flame, and 4 is the flame 3 that is heated by an appropriate means. This is an electrode (hereinafter referred to as a rod) held in the rod. Reference numeral 5 denotes a power supply terminal box, which includes an anode terminal 6 and a cathode terminal 7.

However, as mentioned above. The head 4 and the anode terminal 6 are connected to each other, and the base and the cathode terminal 7 are connected to each other.
A voltage within a range that does not cause dielectric breakdown (arc discharge) between the rods 4, for example a voltage of 2000 V or less, is applied between the anode terminal 6 and the cathode terminal 7. Next, the operation and effects of the above embodiment will be explained with reference to FIGS. 2 and 3.

Generally, in a flame, cations and anions exist in a heated state due to chemical ionization, and the concentration of these ions is maximum near the primary reaction zone, that is, in a region adjacent to the base 1.

By applying a positive DC voltage to the rod 4 inserted into the flame 3 and a negative DC voltage to the base 1, intestinal ions existing near the base 1 are attracted to the base 1 by Coulomb force. That is, in FIG. 2, when no voltage is applied between the base 1 and the rod 4, the flame 3 is maintained in the state shown by the solid line, and when the electricity is applied, the ionized positive in the flame 3 increases. A Coulomb force acts between the ions and the base, and the intestinal ions in the portion where the Coulomb force acts more strongly, that is, the portion closer to the base 1, are more strongly attracted to the base 1. As a result, as will be described later in connection with FIG. 3, the lifting boundary of the lifting flame is also drawn to the vicinity of the flame hole 2 provided in the burner base 1 by Coulomb force and is forcibly held there. Due to the thermal energy as a group of cations in the flame attracted to the base as described above, the base of the flame increases in thickness near the base and is heated at that position, producing an effect that promotes and maintains the fuel, that is, a flame holding effect. The Coulomb force also acts in the outer circumferential direction as shown by the arrows P and P in the figure, and the base of the flame becomes thicker as shown by the chain line 3A and the broken line 3B. Therefore, the thickened flame base synergistically promotes the fuel in the gas near the flame hole 2, and the synergistic effect of the pulling and holding effect of the lift boundary and the flame holding effect due to this Coulomb force causes the flame to increase. Stabilization is demonstrated. Further, in FIG. 3, a general view of the lifting flame is shown. Generally, a lifting flame has a stable fuel portion 3L and unstable fuel portions 3L, 3L, and lift boundary portions 3C, 30 exist between them. As a result, the stable fuel portion 3L of the lifting flame shown by the solid line expels the unstable fuel portion 3L shown by the chain line and the unstable fuel portion 3L2 shown by the broken line due to the above synergistic effect, and is gradually attracted to the base 1 and becomes stable fuel. will be held. That is, due to the Coulomb force generated by the electric field in the flame, the intestinal ion group acting as a spark moves toward base 1, and as a result, the lift boundary descends from 3C to 3D in the same figure, and finally It is confirmed that the flame is maintained stably at the flame hole. Moreover, the above-mentioned effects shown in FIGS. 2 and 3 are further enhanced by increasing the area of the metal portion of the base 1 that contacts the flame and by inserting the rod 4 deeply into the flame 3.

However, the voltage applied between the base 1 and the rod 4 is limited to a range that does not cause dielectric breakdown, and since the resistance of the flame is extremely large at several megaohms, the power consumption for applying the voltage is high. The amount is extremely small. Next, a multi-flame gas burner shown in FIG. 4 will be described with reference to another embodiment of the present invention in which a DC power source is used. .

), 12-12 are each flame 13-12 along the line base.
Flame holes 13 are arranged in a row at intervals such that they contact each other, and the flames 13 are emitted by the fuel of the fuel gas ejected from the flame holes 12 to 12. Well, 1
Reference numeral 4 denotes an electrode (hereinafter referred to as a rod) held by an appropriate means in an appropriate one of the flames 13 to 13 (the figure exemplifies the case of the rightmost flame), and is held by a heat-resistant and insulating material. protected. Reference numeral 15 denotes a power terminal box, which includes an anode terminal 1.6 and a cathode terminal 17. Therefore, the rod 14, the anode terminal 16, and the line base 11
and a cathode terminal 17 respectively, and a voltage within a range that does not cause dielectric breakdown between the base 11 and the rod 14, for example, a voltage of 2000 V or less, is applied to the anode terminal 161.
A voltage is applied between cathode terminals 1 and 7. In the case of this embodiment, the flame 13 at the right end of the figure has the same function and effect as in the first embodiment described above, and fuels in a stable state, and the flames 13 to 13 can contact each other. Since this flame itself has conductivity, if a voltage is applied to the rod 14, a voltage is applied to the entire flame, and the same action and effect as in the first embodiment are exhibited. At the same time, the thermal energy of the flame 13 at the right end
influences the adjacent flame 13, and the adjacent flame 13
is stabilized, and the thermal energy of the stabilized flame 13 is sequentially transferred to adjacent flames 13, thereby stabilizing all flames.

In both of the embodiments described above, a DC power source is used, but the present invention is not limited to this, and an AC power source may also be used.

The AC power supply uses a step-up transformer, etc., and has a voltage of 300 V to 2
000V AC voltage to the base 1 and line base 11
is applied to the rods 4 and 11.

The AC voltage was set at 300 V or higher because the voltage at which the effect of attracting and retaining intestinal ions to the base 1 and line base 11, that is, the Coulomb force, can be effectively exerted is at 300 V or higher, and the reason why the AC voltage was set at 2000 V or lower is as mentioned above. The voltage at which dielectric breakdown (arc discharge) does not occur between the line base 11 and the rods 4 and 14 is 2000 V.
This is because the following. Even when AC voltage is applied to the base 1, line base 11, and rods 4, 11, flames 3, 13 between the base 1, line base 11, and rods 4, 14
Since the concentrations of positive and negative ions inside are equal, the flame 3.1
3 is stabilized, and as mentioned above, the concentration of intestinal ions is maximum in the region adjacent to base 1 and line base 11, and the cations existing near base 1 and line base 11 are concentrated in base 1 and line base 11. Even if a positive voltage is periodically applied to the line base 11, it does not move to the rods 4, 11 side, but remains on the base 1, which has a large metal area heated by the flames 3, 13, and the line base 11, and then 1
When a negative voltage is applied to the line base 11, the positive ions are attracted to the base 1 and the line base 11, and the intestinal ions as a whole are attracted to the base 1 and the line base 11, so in the case of the DC voltage described above. The same action and effect will be achieved. The rest of the structure is the same as that of the previous embodiment. Now, in the claimed invention, as a result of inducing a flame holding effect by attracting cations present in the flame to the burner base by Coulomb force, the lift boundary group 3C due to the flame holding effect and the Coulomb force, The synergistic effect with the 3D attracting and holding effect makes it possible to stabilize the flame and prevent lifting and misfires, so the ejection speed of the fuel gas is de-added and the gas with a high fuel speed is changed from a gas with a high fuel speed to a low speed in the same burner. Not only is it possible to stably supply fuel up to gas, but also the amount of fuel gas per unit time can be increased.

Incidentally, when the method of the present invention is applied to methane gas fuel, it is possible to increase the amount of fuel to a large or medium extent, as is clear from the comparative experimental measurement values shown in FIG. 5, for example. That is, FIG. 5 is a characteristic diagram plotting the boundary points from the flame lift suppression state to the lift generation state when the primary combustion air amount and gas ejection speed are varied. When DC voltage is applied to the flame, the boundary point shifts to the right side compared to when no DC voltage is applied, which clearly confirms the lifting prevention effect, and the gas ejection speed, that is, the combustion amount, decreases when the flame is stable. This shows that it is possible to relatively increase the In addition, unlike secondary equipment, the applied voltage in the present invention can be within a range that does not cause dielectric breakdown, and the effect can be achieved with a small amount of power consumption, so there is no need to increase the dielectric strength of the equipment, and there is no need to increase the dielectric strength of the equipment. There is almost no need to worry about inducing gas emissions or electric shock to the human body.

This is also confirmed by an experiment shown in FIG. 6, which shows the relationship between the applied voltage and the maximum stable fuel amount in methane gas fuel. FIG. 6 is a characteristic diagram plotting the boundary points at which the lift suppression state changes to the lift generation state when the voltage applied to the flame and the amount of gas supplied and burned in the burner are changed.

In the same characteristic diagram, the ratio of primary air volume to theoretical air force (
That is, the applied voltage-combustion amount characteristics are shown when DC voltage and AC voltage are applied with a constant AP value (25%) and when DC voltage is applied at different AP values (40%). That is, judging from each characteristic curve, it is clearly confirmed that a lift suppressing effect exists when a voltage is applied to the flame, compared to the state where the applied voltage is 0 [V], and The lift suppression effect is approximately 500 ~
It is also confirmed that saturation begins at an applied voltage of 800 volts. In particular, when applying a DC voltage, the lift suppression effect is more remarkable than when applying an AC voltage. This can be understood from the fact that, as already mentioned, this is effective only when the electrode 4 is at a positive potential with respect to the burner base 1. can. Note that the method of the present invention is not limited to burners having shapes such as the single-flame hole burner and multi-flame hole burner shown in the above embodiments, and can also be used for combustion methods such as diffusion flame burners and submixed flame burners. It can be used in a wide range of applications.

As described above, according to the method of the present invention, the lifting boundary of the lifting flame is constantly drawn and held near the flame hole of the burner base by the Coulomb force generated by the DC electric field, and gas combustion is promoted in the pupil to this extent. Intestinal ions attracted to the burner base or line base make the base of the flame thicker, and the thermal energy of the cations synergistically creates a so-called flame-holding effect, which lifts the flame. Not only can it be extremely effectively prevented and suppressed, but it is also possible to increase and adjust the amount of combustion.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of an embodiment in which a device used for carrying out the method of the present invention is applied to a single-flame hole burner, Figs. 2 and 3 are explanatory diagrams of its operation, and Fig. 4 is a diagram of the method of the present invention. A schematic explanatory diagram of an example in which the device used for the implementation is applied to a multi-flame burner, FIG. 5 is a diagram of measured values in a comparison experiment of methane gas fuel amount,
FIG. 6 is an applied voltage-maximum stable combustion amount diagram. 1,11...burner base, 3,13...flame, 4,
14... Fin pole, 5, 15... Anode terminal for power supply, 6, 16... Cathode terminal for power supply. Figure 1 Figure 4 Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] 1. Insert the electrode at any position within the flame away from the burner base, and set the electrode to 2,000 degrees within the range that does not cause dielectric breakdown.
A DC voltage of V or less or an AC voltage of 300 to 2000 V is applied between the electrode and the burner base to generate an electric field within the flame, chemically ionizing the cations present in the flame by Coulomb force. By drawing the flame to the burner base, the lift boundary of the flame is forcibly drawn to the flame hole provided in the burner base, and the base of the flame is forcefully drawn and held to the burner base. The base is heated by the thermal energy of the flame to generate a flame holding effect, and the lifting of the flame is suppressed by the synergistic effect of the pulling and holding effect of the lifting boundary part by the Coulomb force and the flame holding effect. 1. A lift prevention method in a gas burner, characterized in that the lift prevention method is made possible.