JPS6069425A - Kerosene burner - Google Patents

Abstract

PURPOSE:To prevent the occurrence of poor ignition and failure in ignition when temperature is low, by a method wherein an element, which is for correcting an ambient temperature and has temperature dependence, is mounted to a flame rod circuit. CONSTITUTION:The value of a resistor 28 is slightly increased, a series circuit of a thermistor 31 and the resistors 28 and 32 are selected so that the same resistance value as previous one is produced at about the normal temperature, i.e., 25 deg.C. Thus, since the resistance value of the thermistor 31 is increased when temperature is decreased, a resistance value is also increased on the whole and discharge is decreased to replenish a decrease in an electric charge in a capacitor 29. Even if, conversely, the temperature is decreased to 25 deg.C or less, the resistor 32 enables prevention of a decrease in the resistance of the thermistor 31. This enables reliable detection of combustion and prevention of the occurrence of poor ignition and failure in ignition even when temperature is low.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to oil burners such as oil fan heaters.

Structure of the conventional example and its problems A conventional oil burner, for example, an oil fan heater, is equipped with an external device as shown in Fig. 1. An oil tank 3 and a burner 4 are installed in the 0 interior, and combustion gas A comes out from the top of the burner 4.
is sent as warm air C into the room from the front louver 7 together with indoor air B by a blower motor 5 and a blower fan 6 attached to the rear surface of the exterior. In addition, the combustion part of the bar 4 is as shown in the second figure, and there is a mesh-like jet port 9 at the top of the bar, and the premixed vaporized part is spouted from this mesh, and from the ignition electrode 10. Sparks are generated in the mesh and ignited, creating a combustion flame 11. A flame rod 12 is installed so as to hit this flame and monitor the combustion flame.

FIG. 3 shows an example of a conventional control circuit. AC power supply 1
3 constitutes a closed circuit with 8 points - relay contact 14 - burner heater 15 - point b - operation switch 16. a-b
Between the points, a second relay contact 17 - a parallel circuit of the blower motor 5 and the burner motor 8 is connected, and a third contact 19 - point 0 - the ura bomb 20 is connected. A high voltage igniter 21 is connected between points c and b, and a control circuit 22 including a relay control and safety device is connected between points a and b. In addition, from the DC constant voltage source 23 generated by this matching a control circuit, 6
It forms a closed loop with point-resistance 24-point e-resistance 25-point f. The other AC power supply 26 has one end protected by a resistor 27-g.
Point - Parallel contact of resistor 28 and capacitor 29 - Point f - F L
A closed loop is formed with the unit 12 and the burner 4. Note that the output of the operational amplifier 30 having positive and negative inputs at points g and e sends a signal to the control circuit 22.

To explain the operation of this device, when the power switch 16 is closed, the heater 15 is turned on to the burner 4 by the action of the control circuit 22.
The vaporizer inside is raised to a constant temperature and maintained. For this purpose, the oil sent by the pump 20 is vaporized by the vaporizer, and is appropriately mixed with the air sent by the burner motor 18.
It gushes out from the gushing mesh 9. At this time, Nupark jumps between the ignition electrode 10 and the mesh and is ignited by the igniter 21. This flame causes a rectified current to flow through the flame rod 12 and the burner. Therefore, a charge detection voltage is generated across the capacitor 29 in FIG. 3, and is determined to a certain value by the resistor 28. - Although the resistance division point e is fixed at a constant value by the power running voltage power supply 23, the flame rod current changes depending on the combustion state. To explain this situation, Figure 4 shows the states at points e and g. In other words, the potential at point e is always constant, but the potential at point g is 0 when there is no combustion, but it is at point 01 during combustion. and the output point becomes high. When there is a lack of oxygen or oil, the potential becomes lower than the reference potential e point, and the output point becomes low to give a signal to the control circuit 22.

There is no problem under normal conditions like this, but when the outside temperature is low, especially from 0 to -200G, the oil flow rate cannot be raised much due to the relationship between the air density increasing and the oil vaporization. As the combustion progresses, there will be excess air. Follow 'C
The combustion flame tends to lift, the flame lot current decreases, and the potential at point g sometimes falls below point e, as shown by g'C.
come. In particular, when the normal oxygen deficiency level is defined as e, when the temperature gets low, it falls below this level and becomes stable at around 02 points. In this way, there are cases where even a normal sequence does not work. In reality, the position of g point is well determined at e in normal conditions, oxygen deficiency, ignition, misfire, etc., but when the temperature gets low like this, the value of g point becomes the limit. As shown in the figure, there was a problem in that the overall temperature decreased and the point e did not change, so combustion could not be detected at low temperatures, resulting in poor ignition.

Purpose of the Invention The present invention was made in view of the problems mentioned in 2.It is an object of the present invention to correct the decrease in flame lot current due to ambient temperature to prevent ignition failures from occurring at low temperatures. It is.

DESCRIPTION OF THE INVENTION In order to achieve the above object, the present invention includes a gold-plated element C that is temperature-dependent for circumference correction in a frame lot circuit.

DESCRIPTION OF EMBODIMENTS One embodiment will be explained below using FIGS. 5, 6, and 7.
To explain, Fig. 5 is the illumination (fi11 times V each figure, especially the one showing the frame loft circuit part). be.

In FIG. 5, a series circuit consisting of a therminutor 31 and a new resistor 32 is connected in parallel to the resistor 28 of the circuit of the embodiment shown in FIG. Further, a second operational amplifier 34 is provided, in which a resistor 33 is connected in series with the resistor 25, and its connection points l and g serve as positive and negative inputs.

Next, the operation of this circuit will be explained. The DC power supply 23 and the resistor 24 - point e, the resistor 25 - 1 point, and the resistor 33 - point f form a closed loop, and a constant voltage is generated at points e and 1. Then'C1 AC power supply 26-d point-resistance 27-
Point g - capacitor 29 - point f - flame rotor 12 - burner 4 fl/I loop. Therefore, the potential at point C8 is charged only by the direct current due to the rectifying action of the flame rod, and if the combustion state is properly stabilized, the charging voltage becomes high. In this case, the four charges are appropriately discharged by the resistor 28, so the g-point potential is a certain value, for example, GQVC in FIG.
;hru. However, when the ambient temperature bottoms out, the amount of air required for combustion increases, so the charging force decreases, and the characteristic G
As shown in □, the level of oxygen deficiency increases and the GL begins to drop.

Therefore, in this embodiment, the value of the conventional resistor 28 is increased slightly, and a series circuit of the thermistor 31 and the resistor 32 is connected to it, so that the thermistor 31 has the same resistance value as the conventional one at around room temperature (25 degrees Celsius). , resistors 28.32 are chosen. However, according to the conventional configuration, when the temperature drops, the resistance value of the thermistor 31 increases, so the female resistance value increases as a whole, and the amount of C discharge slightly compensates for the decrease in the charge charged to the capacitor. cormorant. As a result, the characteristics will not deteriorate as much as in G1. On the other hand, when the outside temperature drops below 25°C, the resistance 32 can prevent the decrease in the resistance of the thermistor 31, resulting in a resistance of 5g.

can be stabilized.

In addition, in FIG. 5, the operational amplifier 30 whose negative input is at point e determines the oxygen deficiency detection level g1, and that at one point determines the misfire detection level /L/g2. The value g□ when relatively stable, such as level/l/g 1
This is related to control of parts close to .

Further, FIG. 7 shows another embodiment in which one to several diodes 35 are connected in series with the resistor 28 of FIG. 5, and even with such a configuration, sufficient temperature compensation may be achieved in some cases.

Effects of the Invention As described above, the present invention corrects the reduced part of the flame loft current using a temperature-dependent element such as a thermistor, thereby reducing the influence of temperature characteristics as a whole.

Therefore, combustion can be reliably detected even at low temperatures, and stable combustion control can be achieved without any errors that may cause ignition failures.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional oil combustor, FIG. 2 is a sectional view of the burner, FIG. 3 is a circuit diagram thereof, and FIG. 4 is an explanatory diagram showing the operating voltage. Fig. 5 is a circuit diagram of an oil combustor in an embodiment of the present invention, Fig. 6...capacitor, 2
8...Resistor, 31...Temperature dependent element (thermistor), 35...Temperature dependent element (diode). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure ! Fig. 2 Fig. 4 Noku α Sunshi 1 No ζ 11 Ken, Fig. 5 d Fig. 6 1? θ −ρ o 10 2030 Temperature Figure 7

Claims (1)

[Claims] In a burner that vaporizes and burns kerosene, and in an oil combustor that detects the combustion state using the flame-low phenomenon, a signal is generated by comparing the reference voltage determined by the C1 constant voltage device and the capacitor voltage charged by the rectification phenomenon. lr: constitutes a circuit that emits light, and iiJ capacitor voltage is changed by 4 degrees by a temperature-dependent element connected in parallel to reduce the flame loss (flame loss) and current due to changes in the combustion state depending on the ambient temperature. Oil burner with correction.