JPS60122819A - Liquid fuel combustion apparatus - Google Patents

Abstract

PURPOSE:To enable to stabilize ignition by properly maintaining the ratio of combustion air and liquid fuel during the time in low temperature, by providing a means to change the piping resistance of an oil feed pipe in accordance with the change in temperature in combustion air, to the oil feed pipe to feed fuel. CONSTITUTION:A needle 8 as a variable means 6 to vary the piping resistance of an oil feed pipe 2 is movably provided in the piping resistance variable part 7 of a pipe 2. The needle 8 is fixed to a thermally responding element 9, a shape memory alloy for example, in the shape of a spring, provided exposed in an air passage 5. In the normal time when the temperature in combustion air passing through the air passage 5 is higher than a set value, the thermally responding element 9 is contracted. Accompanied with the contraction, the needle 8 is moved and is inserted longer into the piping resistance variable part 7, so that the piping resistance is increased. While at the time when temperature is lower than the set value, the thermally responding element 9 exposed to the air passage 5 is lengthened. The needle 8 is moved being accompanied with the elongation, and the inserted part of the needle 8 into the piping resistance variable part 7 becomes shorter, so that the piping resistance is decreased. The rate of feed oil is increased by the decrease of piping resistance. The moving distance of a neelde 8 is designed so that the feed liquid fuel and the combustion air can get the optimum ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a combustion device using kerosene or the like as fuel.

Structure of the conventional example and its problems A conventional liquid fuel combustion device, for example, a hot air heater that uses kerosene as fuel, has a vaporization combustion section A and fuel is supplied to the vaporization combustion section A, as shown in Fig. 1. Oil pipe B and this oil pipe B
a combustion blower supplying combustion air to the vaporization and combustion section A; a blower path E from the blower to the vaporization and combustion section A; Pressurized chamber F
It consists of a pressurizing pipe G that connects and communicates with. According to this configuration, fuel is supplied in proportion to the amount of combustion air sent to the vaporization combustion section A, and there is an advantage that the air-fuel ratio can be maintained substantially constant. In other words, a part of the air supplied from the blower is added to the leveling device C and pushes out the oil in the leveling device C, so if the amount of air blown increases, the oil will also increase, and if the amount of air blown decreases, the oil will also increase. The ratio decreases and remains almost constant. However, in the case of low temperatures, the kerosene supply amount decreases due to an increase in the viscous resistance of kerosene in the oil pipe B, and the density of combustion air passing through the air passage E increases, causing the air-fuel ratio to become unbalanced. However, there was a problem in that too much air resulted in poor ignition and poor combustion.

OBJECTS OF THE INVENTION The present invention was made in view of the above-mentioned problems, and an object of the present invention is to ensure stability of ignition and combustion in a liquid fuel combustion device.

Structure of the Invention In order to achieve the above object, the present invention provides an oil supply pipe that supplies fuel with a variable means for varying the piping resistance of the oil pipe according to the temperature of combustion air, thereby increasing the viscous resistance of kerosene at low temperatures. The system is designed to reduce the piping resistance of the oil transmission pipe when the kerosene is used, and to increase the piping resistance of the oil transmission pipe when the viscous resistance of kerosene is low under normal conditions. If the temperature of the combustion air drops below the temperature that causes the problem, the piping resistance of the oil pipe decreases, which increases the amount of oil sent and balances it with the air amount, preventing ignition failure and combustion failure. It looks like this.

Description of examples An example of this will be described below with reference to FIGS. 2 and 3.

In FIG. 2, 1 is a vaporization combustion section that vaporizes and burns liquid fuel, 2 is an oil pipe that supplies fuel to the vaporization and combustion section 1, and 3
4 is a combustion blower that supplies combustion air to the vaporization and combustion section 1; and 5 is a blower that guides combustion air from the blower 4 to the vaporization and combustion section 1. A pipe 6 is a variable means for varying the piping resistance of the oil feed pipe 2.

FIG. 3 is an enlarged view of the main part of the variable means 6. As shown in FIG.

7 is a pipe resistance variable portion in the oil pipe 2; 8
is a needle installed movably within the piping resistance variable portion 7 of the oil feed pipe 2, and the needle 8 is installed in the air flow path 5.
A spring-shaped thermally responsive element, such as a shape memory alloy 9, provided exposed therein is fixed.

In the above configuration, under normal conditions when the temperature of the combustion air passing through the air passage 5 is higher than a predetermined temperature, the thermally responsive element 9 contracts, and as a result, 5. As the needle 8 moves, the insertion distance of the needle 8 in the piping resistance variable portion 7 becomes longer, and the piping resistance increases.

The shape and dimensions of the piping resistance variable portion 7 and needle 8 are as follows:
At room temperature, the ratio between the amount of liquid fuel supplied and the amount of combustion air blown is set to be the optimum ratio, and normally the ratio between fuel and air is adjusted in the same way as described in the conventional example. In other words, the air-fuel ratio is kept constant, resulting in good combustion.

On the other hand, when the temperature is lower than a predetermined temperature, the thermally responsive element 9 exposed in the air passage 5 expands, and the needle 8
moves, the insertion distance of the needle 8 in the piping resistance variable portion 7 becomes shorter, and the piping resistance becomes smaller. This increases the amount of oil sent, but the distance the needle 8 moves even at low temperatures. The ratio between the amount of liquid fuel supplied and the amount of combustion air blown is set to be optimal.

Therefore, the air-fuel ratio in the vaporization combustion section 1 does not change significantly even at low temperatures, and there is an effect that stable ignition and combustion can always be ensured.

In the above embodiment, a thermally responsive element is used as the variable means, but a solenoid operated by the output from the temperature detection element may also be used. Examples in this case are shown in FIGS. 4 and 5. Explain using.

In FIG. 4, as in FIG. 3, 5 is an air passage, 7 is a piping resistance variable portion in the oil pipe, and 8 is a needle.

Reference numeral 10 denotes a solenoid that moves the needle 8. When the temperature of the combustion air is below a predetermined temperature, the solenoid 10 moves the needle 8, reducing the piping resistance in the piping resistance variable portion 7. It is set to be. FIG. 5 shows a control circuit for driving the solenoid 10, which is the same as FIG. 15 is a relay coil, and 16 is a contact point of the relay.

In the above configuration, when the switch 11 is turned on, the ignition circuit 12 and the combustion circuit 13 are activated, and at the same time, the temperature detection circuit 14 detects that the solenoid 10 to move the needle 8 to reduce the piping resistance in the piping resistance variable portion 7 and increase the amount of oil fed. Also, when the temperature is higher than a predetermined temperature, the solenoid 10 moves the needle 8. It is set so that the position is moved, the pipe resistance in the pipe resistance variable portion 7 is increased, and the amount of oil fed is decreased.

Therefore, in this embodiment as well, as in the case where a thermally responsive element is used as the movable means, the air-fuel ratio in the vaporization combustion section does not change significantly even at low temperatures, and stable ignition and combustion can always be ensured.

Note that a thermistor or the like is normally used as the temperature detection element, and it is best to install it in the air passage or at the intake port of the combustion blower, but it is best to install it in the air passage or at the inlet of the combustion blower. If the temperature difference between the atmosphere and the combustion air is small, the atmosphere may be detected directly.

Effects of the Invention As described above, according to the present invention, the ratio between the amount of combustion air and the amount of liquid fuel can be maintained at an appropriate level at low temperatures, making stable ignition possible and preventing abnormal combustion, etc. This has a great effect on improving combustion stability.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration in a conventional example, FIG. 2 is an explanatory diagram of a schematic configuration in an embodiment of the present invention, FIG. 3 is an enlarged view of the main part of the movable means in the embodiment of FIG. 2, and FIG. 5 is an enlarged view of the main part of the movable means in another embodiment, and FIG. 5 shows the control circuit 7 in the embodiment of FIG. 4. 1. Gasification combustion section, 2. Oil pipe, 4. Combustion blower, 6. Variable means for varying piping resistance of the oil pipe, 9. Thermal response element as variable means, 10. Variable. Solenoid as a means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure〃 Figure 4

Claims (3)

[Claims] (1) Consisting of a vaporization combustion section that vaporizes and burns liquid fuel, an oil pipe that supplies fuel to this vaporization combustion section, and a combustion blower that supplies combustion air to the combustion section, A liquid fuel combustion device equipped with a variable means that changes the piping resistance of the oil pipe according to the temperature of the air. (2) The liquid fuel combustion device according to claim 1, wherein the variable means uses a thermally responsive element. (3) The liquid fuel combustion device according to claim 1, wherein the variable means is a solenoid operated by an output from a temperature detection element.