JPH01131806A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To enable an automatic cleaning of an injection nozzle to be carried out in case of operations other than an ignition or an extinction by a method wherein as tar is adhered to the injection nozzle to decrease a flame during combustion, this is detected by a flame sensing rod and a needle is operated. CONSTITUTION:As a tar is adhered to a nozzle hole to cause a flame current value to be gradually decreased and shows a state before it is dropped down to such a level as an automatic extinction level not capable of keeping an ignited condition, a flame sensing rod 10 may detect this state to cause the combustion to be stopped at once. For example, a full-wave rectification voltage of 100V is intermittently applied to an electromagnetic solenoid 5, a needle 4 is reciprocated within the injection nozzle 2 and then the nozzle hole is cleaned with an extremity end of the needle 4. In this way, the tar is removed, so that a cleaning such as after non-fuel burning is not required and thus a normal combustion state can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid fuel combustion device that burns liquid fuel.

[Prior Art] This type of liquid fuel combustion apparatus is shown in FIG. FIG. 1 is a partial cross-sectional view showing the outline of the configuration of this type of liquid fuel combustion device, in which (1) is a vaporization pipe, (
2) is a jet nozzle, (3) is a thermistor, (4) is a needle, (5) is an electromagnetic solenoid, (6) is a fuel pipe, (
7) is a pump, (8) is a burner, (9) is a spark plug, and (10) is a flame detection rod.

The vaporization tube (1) has a cylindrical outer tube (1a) made of heat-resistant stainless steel, etc., and a vaporization stabilizing member (1b) made of a metal mesh etc. installed in order to increase heating efficiency.
sandwiched between them to form a vaporization chamber, and both ends are welded to the sheathed heater (1c). Further, a jet nozzle (2) is provided at one end of the vaporizing tube (1), and a thermistor (3) installed here constantly detects the temperature of the vaporizing tube (1). The needle (4) is a member that opens and closes the jet nozzle (2), and is controlled by an electromagnetic solenoid (5).

Further, a fuel pipe (6) is connected to the discharge side of the pump (7), and this fuel pipe (6) is connected to one end of the vaporizing pipe (1) on the opposite side from the jet nozzle (2). There is.

A burner (8) is installed opposite the ejection nozzle (2), and vaporized gas ejected from the ejection nozzle (2) during combustion flows into the burner to form a mixture with air. In addition, ignition is performed by a spark generated by the spark plug (9),
The combustion state is electrically detected by a flame detection frame (10) to check combustion safety.

Next, the operation of the conventional liquid fuel combustion device will be explained. To carry out combustion, first turn on the power to the sheathed heater (LC), make the sheathed heater (1c) generate heat, and gradually heat the vaporization tube (1) with the heat generated by the sheathed heater (1c) until it reaches a predetermined temperature. raise.

When the vaporizer pipe (1) heats up, the thermistor (3) detects this and drives the pump (7) to pump liquid fuel into the fuel pipe (
6) into the vaporization chamber, that is, between the outer cylinder (1) and the sheathed heater (1c).

The liquid fuel sent into the inside of the vaporizer tube (1) is transferred to the outer tube (
It is vaporized by contacting the inner wall surface of la), the outer wall surface of the sheathed heater (1c), and the vaporization stabilizing member (1b), and becomes vaporized gas. Next, the electromagnetic solenoid (5) is energized and the needle (4) is attracted toward the solenoid (5). The nozzle hole (hereinafter referred to as the nozzle hole) is opened and vaporized gas is ejected into the burner (8). At this time, the vaporized gas ejected from the ejection nozzle (2) is supplied to the burner (8) as a mixture by suctioning air by the ejector effect. When the spark plug (9) generates a spark, the air-fuel mixture supplied into the burner (8) ignites and becomes a flame. This flame is detected by the flame detection frame (10) during combustion.
It is monitored by the system to monitor for abnormal combustion, extinction, etc.

Next, when stopping combustion, the operation of the pump (7) is stopped, the supply of liquid fuel is stopped, and the needle (4) is returned to its original position by de-energizing the electromagnetic solenoid (5). Return to position and close the nozzle hole with the tip.

Next, the operation of the needle (4) in the conventional device will be explained as follows.
This will be explained with a diagram. Figure 4 shows the needle (
4) is a diagram showing the voltage control applied to the electromagnetic solenoid (5) that controls the operation of the solenoid (5), and in FIG. 4, the voltage is oV until ignition, and the needle (4) closes the nozzle hole. . At the time of ignition, a voltage of 1 oov is applied, and the solenoid (5) is energized to the maximum and attracts the needle (4). Further, during combustion, a voltage of 24 V is applied, and during the ninth extinguishing period in which the needle (4) is held in the suction position, the voltage is set to 0■, so that the needle (4) closes the nozzle hole.

By moving the needle (4) in parallel inside the jet nozzle (2) in this way, the nozzle hole opens and closes, and the heavy content (hereinafter referred to as tar) in the fuel gas vaporized into the nozzle hole Cleaning off any buildup.

[Problems to be Solved by the Invention] The conventional liquid fuel combustion device as described above operates as described above, so that the needle moves during ignition and extinguishing to clean tar attached to the nozzle hole. However, if a liquid fuel with a high heavy content is used, a large amount of tar will be generated and the tar will not be removed smoothly, and the tar will end up adhering to the nozzle hole. Normal use is often impossible. As a countermeasure in this case, there is a method of dry-firing the jet nozzle and cleaning it, but the operation is complicated, and if the jet nozzle is made of material such as aluminum,
There was a problem in that it was not effective because it could not be baked at a high temperature.

This invention was made to solve this problem, and aims to provide a liquid fuel combustion device in which tar is less likely to adhere to the jet nozzle.

[Means for Solving the Problems] In the liquid fuel combustion device according to the present invention, tar adheres to the jet nozzle and the nozzle hole becomes clogged, resulting in poor combustion efficiency and a decrease in the size of the flame during combustion. When the flame becomes small, the flame detection frame detects this and automatically operates the needle to clean the nozzle hole.

[Function] In this invention, when tar adheres to the jet nozzle and the nozzle hole becomes blocked, the combustion efficiency deteriorates and the size of the flame during combustion becomes small, this is detected by the flame detection rod, Since the needle is automatically operated to clean the nozzle hole, the ejection nozzle can be cleaned automatically even when the fire is ignited or extinguished.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

The structure of the liquid fuel combustion apparatus according to the present invention is the same as the conventional apparatus shown in FIG. 1, and the explanation thereof will be omitted here. Further, the basic operations from ignition to combustion and extinguishing are the same as those of the conventional device, and the explanation will be omitted here.Hereinafter, the features of this invention that are different from the conventional device will be explained.

FIG. 2 is a diagram showing a comparison between the electrically measured value of the flame size (hereinafter referred to as flame current value) using the flame detection rod (10) shown in FIG. 1, and the combustion pattern. So, the second
In the figure, for example, when normal kerosene with a normal tar content is used, approximately 15 μA is measured in strong combustion and approximately 10 μA in weak combustion. However, when inferior kerosene with a high tar content is used, the tar adheres to the nozzle hole, reducing combustion efficiency and causing the flame current value to gradually drop as shown in FIG.

In this invention, as tar adheres to the nozzle hole, the flame current value gradually decreases and reaches the automatic extinguishing level (4 μA in the example in Figure 2) where the flame current value can no longer be maintained.
) (6 μA in the example in Figure 2), -
For example, the combustion is stopped for 100 seconds as shown in Figure 3.
A full-wave rectified voltage of 1 is intermittently applied to the electromagnetic solenoid (5), and the needle (4) is reciprocated within the jet nozzle (2) to clean the nozzle hole with the tip of the needle (4).

That is, in this invention, when tar adheres to the jet nozzle (2) and combustion is not performed normally, the needle (4) automatically moves back and forth to remove the tar, so cleaning such as dry firing is not necessary. It is not necessary and the combustion state is always maintained normally.

In the above embodiment, the electromagnetic solenoid is caused to reciprocate during combustion, but the same effect can be achieved by operating it for a certain period of time during preheating or after extinguishing the fire.

Also, when operating the electromagnetic solenoid, the heater is simultaneously energized to maintain the nozzle at a high temperature.
The tar solidifies and becomes easier to clean.

[Effects of the Invention] As explained above, when tar adheres to the jet nozzle and the nozzle hole becomes blocked, combustion efficiency deteriorates and the size of the flame during combustion becomes small, the flame detection rod Since we decided to detect this and automatically operate the needle to clean the nozzle hole, it is possible to automatically clean the jet nozzle even when igniting or extinguishing the fire, thereby preventing problems such as dry firing. There is no need for cleaning, and the combustion state can always be maintained in a normal state.

[Brief explanation of the drawing]

Figure 1 is a partial sectional view showing the outline of the configuration of a liquid fuel combustion device, Figure 2 is a diagram showing a comparison between flame current values and combustion patterns, and Figure 3 is a full-wave rectifier that controls the electromagnetic solenoid in this invention. FIG. 4 is a diagram showing a control voltage applied to a conventional electromagnetic solenoid. (2) is a jet nozzle, (3) is a thermistor, <4) is a needle, (5) is an electromagnetic solenoid, and (10) is a flame detection rod. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] An ejection nozzle that ejects vaporized gas obtained by vaporizing liquid fuel from a nozzle hole, a needle that moves back and forth within the ejection nozzle to open and close the nozzle hole, and a needle that controls the size of the flame during combustion. In a liquid fuel combustion device equipped with an electrically detected flame detection rod and an electromagnetic solenoid that controls the needle according to the size of the flame detected by the flame detection rod, the size of the flame during combustion is less than a standard value. When the flame has become hot, the flame detection rod detects this and intermittents the current flowing through the electromagnetic solenoid multiple times, causing the needle to reciprocate multiple times to remove the tar attached to the jet nozzle. A liquid fuel combustion device characterized by comprising means for removing by reciprocating movement of a needle.