JPS6250727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves safety by detecting a decrease in oxygen concentration (hereinafter referred to as oxygen deficiency) in a liquid fuel combustion device such as an kerosene stove in which the wick is moved up and down. Generally, liquid fuel combustion devices equipped with an oxygen deficiency sensor are designed to stop combustion when the oxygen concentration reaches, for example, 16%. In contrast, the present invention prevents the combustion from stopping due to lack of oxygen by notifying the user before stopping the combustion for such a fixed amount of combustion, and extinguishes the fire only in the final case.

An embodiment of the present invention will be described below based on the accompanying drawings.

FIG. 1 shows an embodiment of the present invention.
is a cylindrical lamp wick, which can be raised and lowered by arm 2'. The left end of this arm 2' is attracted by a magnet 3' when it is lowered. When ignited with the lamp wick 1' raised, the lamp wick 1' burns, and at that point the blower motor 4 is operated and the fan F is rotated. Wind A from the fan F enters from the intake port B and flows between the cylindrical guide plates 5 and 6, so that the combustion gas C is sucked in from between the disc-shaped guide plate 6 and the cylindrical guide plate 7. The mixture is mixed and turned into hot air, which is discharged in the direction of D. An intake thermistor 8' is provided at the intake port B, which is the air passage, and an exhaust thermistor 9' is provided at the exhaust port. In this way, the temperature difference caused by combustion can be detected by thermistors 8' and 9', and if combustion deteriorates due to lack of oxygen or tar adhesion, the temperature difference disappears, so this can be used. It detects it. When this value reaches a certain level, the alarm device 10' is activated to issue an alarm. When there is a lack of oxygen, the windows are opened to ventilate the tank, and when tar is generated, air firing is performed to remove the tar. If the alarm is not noticed and the combustion worsens, the current to the magnet 3' is stopped, the left end of the arm 2' is unattached, and the wick 1' is lowered to extinguish the fire. In this way, the kerosene stove provides comfort, ensures safety, and allows long-term use. Incidentally, when dry-firing, it is sufficient to carry out dry-firing until the alarm 10' no longer issues an alarm, and therefore it can also be used to check the dry-firing state.

Figure 2 shows a circuit, in which 1 is a power supply, 2 is a switch, 3' is the magnet shown in Figure 1, and 4 is a transistor that operates it.These constitute a closed loop, and switch 2 and magnet 3′,
Connect each connection point of transistor 4 and power supply 1 to a
Point and point b. Between points a and b, there is a suction thermistor 8' and a resistor 5, an exhaust thermistor 9' and a resistor 6,
The series circuits of resistors 15 and 16 and resistors 19 and 20 are connected in parallel, and their connection points are c,
Let d, h, and j. Also, differential amplifiers 14, 17, and 21 are connected between points a and b. A point c is connected to the positive input point e of the first differential amplifier 14 through a resistor 11, and a point d is connected to a negative input point f through a resistor 7. Further, a resistor 13 is connected to the output point g from the negative point, and a resistor 12 is connected between the points e and b. The + side input of the second differential amplifier 17 is connected to g, the - side input is connected to point h, and the series circuit of the resistor 18 and alarm 10' is connected from the output point i to point b. The + side input of the third differential amplifier 21 is connected to point j, the - side input is connected to point g, and the output k connects a series circuit of resistors 22 and 23 to point b. Further, a connection point l between the resistors 22 and 23 is connected to the base of the transistor 4. Finally, connect the timer 25 to points a and b, and make its output l
After the voltage is applied, the transistor 4 operates for a while. A diode 24 is connected in parallel to the magnet 3' with the point a as its cathode.

The operation of such a circuit will be explained. First, in FIG. 1, when the arm 2' is set, a switch 2 is closed.The operation will be explained below with reference to FIGS. 2 and 3. The supplied voltage remains applied to each circuit and combustion begins.
First, timer 25 operates, so transistor 4
operates, and the magnet 3' attracts the arm 2'. At this time, the temperature of the exhaust thermistor 9' is still low, and therefore point d has approximately the same potential as point c. After a while, the temperature of the exhaust gas increases, and as a result, the potential at point d becomes higher than that at point c.
Therefore, the potential at point f also becomes higher than that at point e, but since the high temperature side potential is on the negative side of the differential amplifier 14, the potential at output point g is (potential at point C) - (d The potential at point d) is multiplied by a certain factor, so as the exhaust temperature rises, the potential at point d also rises,
The potential at point g (hereinafter referred to as V _p ) is decreasing.
Figure 3 shows this situation, where the exhaust temperature and V _p
This is what is shown. When the intake temperature is constant, the higher the exhaust temperature, the lower V _p becomes. Further, when the exhaust gas temperature is constant, the lower the intake temperature, the lower V _p becomes. In other words, if the temperature difference is constant, the output V
_p is constant, and as the temperature difference increases, V _p decreases. In this way, at the beginning of combustion, the exhaust temperature is low, so the output V _p is high, but when steady combustion occurs, V _p becomes low, and each resistance is set so that it becomes 0. Therefore, at the beginning of combustion, V _p is large, so in the differential amplifier 17, the potential at point g is higher than at point h, and therefore the output at point i is in a high state, and a lamp is activated as an alarm 10'. This lights up when using
Issue an alarm. Similarly, since the point g is higher than the point j, the output k of the third differential amplifier 21 is in a low state, and no signal is output to the transistor 4, but a signal is output from the timer 25. Magnet 3' is operating. Next, as the exhaust temperature gradually rises, V _p becomes lower in Figure 3, and finally
When Vo becomes substantially 0, the i point becomes low and if a lamp is used as the alarm 10', it goes out, and similarly the k point becomes high and a signal enters the base of the transistor 4 and the magnet 3 ' will now work. Nowadays, it's timer 2
Eliminate the output from 5. In other words, under normal conditions, magnet 3' operates because the temperature difference is high,
When a lamp is used as the alarm 10', it is not lit. Next, regarding the case of oxygen deficiency, if the oxygen concentration in the room decreases to P ₁ as shown in Figure 4, the combustion of the lamp wick 1' will deteriorate and the exhaust temperature will gradually decrease, so it will be just like the normal condition. It will be the same as the initial stage, and V _p will not become so low. When the oxygen concentration is normal, combustion occurs normally, so V _p is almost 0.
However, as the oxygen concentration decreases, V _p gradually increases and becomes constant at a certain point. However, if the maximum output V _p is set to 10 [V], and if it rises to 6 [V] first, then if the h point is set to 6 [V] in Figure 2, the alarm will be activated.
If you use a lamp as 0', it will light up. Assume that if the device is used as it is, the oxygen concentration in the room will further decrease, and V _p will increase to 8V. When point j in Fig. 2 is set to 8V, the output point k becomes low and transistor 4 turns OFF, magnet 3' releases lever 2', lever 2' returns to its original position, and lamp wick 1' lower to stop combustion. Since the oxygen concentration varies linearly with the oxygen concentration, the alarm and the operation of the magnet 3' will be performed correctly.

Next, when tar adheres to the lamp wick 1', the amount of combustion decreases and the state becomes exactly the same as the decrease in oxygen concentration, and an operation equivalent to the oxygen-deficient operation described above is performed. In this way, it operates normally both when oxygen is lacking and when tar is present.

As described above, in the present invention, an alarm is first issued when there is a lack of oxygen or poor combustion, so combustion can continue if ventilation or air combustion of the wick is performed, and if this is not done, the fire will be extinguished, so it is not recommended for use. It is safe and has a long lifespan since air combustion is performed at the right time.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a circuit diagram, and FIGS. 3 and 4 are characteristic diagrams. 1'...Light wick, 10'...Alarm, F...Fan.

Claims (1)

[Claims] 1. A self-thermal vaporization combustion section that heats and vaporizes the liquid fuel sucked up by the lamp wick using combustion heat itself and burns it, and a combustion gas from this autothermal vaporization combustion section that mixes air sucked from inside the room. A first temperature detection element provided in a passageway for indoor air to be sucked in by the blower fan to be discharged into the room, and a second temperature detection element provided in a passageway for warm air in which the indoor air and combustion gas are mixed. a temperature detection element; a comparison detection unit such as a comparator that detects a temperature difference between the two temperature detection elements;
A combustion control section that issues an alarm when the temperature difference between the two temperature detection elements becomes less than a certain value based on the output from the comparison detection section, and stops combustion in the combustion section when the temperature difference becomes even less than the certain value. A liquid fuel combustion device.