JPS5939647B2 - Combustion safety device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustion safety device that is effective not only when fuel is extinguished, but also particularly when the air in a room is contaminated and is in a so-called oxygen-deficient state.

Configuration of conventional example and its problems Figure 1 shows a thermocouple type combustion safety device which is also commonly used in the past. Primary air port 4 on the end peripheral wall
5 is a gas supply pipe, and 6 is a thermocouple, which is electrically connected to a solenoid valve (not shown) provided in the middle of the waste supply pipe 5.

In the above device, the scum enters from the scum supply pipe 5 and is ejected into the burner body 1 through the nozzle 3, and the ejector action accompanying the ejection causes primary air to be sucked through the primary air port 4, and The mixture is mixed, and is combusted by receiving secondary air at the burner port 2 to form a flame 7.

The above combustion method is generally called the Bunsen method.
The inner flame a and the outer flame form a flame 7.

The thermocouple 6 is heated by this flame and generates a thermoelectromotive force that can keep the solenoid valve open. Therefore, when the combustion flame 7 is extinguished due to wind, etc., the solenoid valve is closed for safe operation. It is something.

In addition, the flame 7 is blown away when the oxygen concentration in the combustion air decreases, even in a so-called oxygen-deficient state, and therefore the thermoelectromotive force of the thermocouple 6 decreases, closing the solenoid valve.
A kind of oxygen deficiency safety operation can be expected.

However, expecting a completely safe operation due to lack of oxygen from the above-mentioned device, which was originally intended as a countermeasure against blowouts caused by wind, etc., had the following major problems.

That is, the first point is that the blow-off of the flame 7 is 2.
This phenomenon is caused by the mode of air flow and causes large variations in the oxygen concentration value in the air that causes the above-mentioned blow-off, the so-called "blown-off oxygen concentration value," which makes it unreliable as an oxygen deficiency safety measure. .

The second problem is that even if the flame 7 is once blown away, it can be easily re-ignited by the combustion heat of the main burner, making it susceptible to the influence of surrounding conditions.

A third point is that the blown-off oxygen concentration value varies depending on the type of debris.

In other words, when comparing methane-based scum (natural scum) and hydrogen-based scum (urban scum), the former gas is much more likely to blow off than the latter gas, and especially the latter, hydrogen-based scum, is more susceptible to primary flames. Even if the flame tries to blow off, the secondary flame remains at the flame mouth, resulting in stable combustion with a low oxygen concentration.

For this reason, the blown-off oxygen concentration values of the two types of dregs differ greatly.

In addition to this, even for the same waste type, the concentration of blown oxygen differs due to seasonal component fluctuations and supply pressure fluctuations.

OBJECT OF THE INVENTION The present invention solves such conventional problems, and is capable of detecting oxygen deficiency without being affected by external influences, and in particular, with respect to hydrogen-based scum, even when the composition of these scum changes depending on the season. The purpose is to blow out the flames so that the fire can be blown out.

Structure of the Invention The present invention comprises a burner so as to form a primary flame and a secondary flame that burn by limited secondary air at a certain distance, and a heater such as a thermocouple in the heating area of the primary flame. A secondary flame detection element is provided, this primary flame detection element is connected to a valve, and an auxiliary air hole is provided to supply controlled secondary air to the outer cylinder near the primary flame opening. When the oxygen concentration decreases, the primary flame is blown out, the output of the primary flame detection element changes, and the fuel control valve is closed.

Description of examples An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2, reference numeral 11 denotes a burner body for ignition, etc., provided in the vicinity of the main burner, and is composed of an inner cylinder 12 and an outer cylinder 13.

The outer cylinder 13 has a secondary flame port 14 at the upper end, and the opening degree is controlled by a damper 29 on the lower peripheral wall, and an auxiliary air port 30 for supplying limited secondary air is further provided at the lower end opening edge. Inwardly flange portions 15 are respectively formed thereon.

Reference numeral 16 denotes a mounting cylinder that is diagonally connected to the outer cylinder 14.

On the other hand, the inner cylinder 12 has a primary burner port 17 at its upper end that faces into the outer cylinder 13 and is located a certain distance below the secondary burner port 14, and further has a primary air port 1B formed in the lower peripheral wall. be.

The inner cylinder 12 has a flange 19 provided in the middle thereof.
After contacting the upper surface of the flange portion 15 of the outer cylinder 13, the inner cylinder 1
The nut 21 to be screwed onto the threaded part 20 of No. 2 is inserted into the banking 22.
It is removably attached to the outer cylinder 13 by being pressed against the lower surface of the flange portion 15 via.

23 is a gas nozzle attached to the lower opening of the inner cylinder 12; 24;
1 installed near the primary flame port 17 via the mounting tube 16
Next, a flame detection element (hereinafter represented by a thermocouple) is electrically connected to a solenoid valve (not shown) in the gas supply path.

In the above configuration, the gas ejected from the gas nozzle 23 and the primary air sucked from the primary air port 18 are
2, the secondary air is sufficiently mixed in the auxiliary air port 30, and the secondary air is combusted at the primary flame port 17 to form one flame A consisting of an inner flame A' and an outer flame A. Form.

Further, this combustion gas is ejected from the secondary flame inlet 14 of the outer cylinder 13, obtains air from the surroundings, that is, secondary air, and burns to form the secondary flame B.

The thermocouple 24 is located in contact with or near the highest temperature flame surface of the flame A, and therefore
When the flame A is formed, its heating generates a thermoelectromotive force capable of opening and holding the solenoid valve.

By the way, since the amount of secondary air in the independent flame A is regulated, it is under unstable combustion and is very sensitive to oxygen concentration.

Therefore, when the oxygen concentration in the air flowing in from the primary and auxiliary air ports falls below a certain level, the first flame A will be blown away, the thermoelectromotive force of the thermocouple 24 will disappear, the solenoid valve will close, and the subsequent gas supply will be cut off. It is.

This one flame A is stabilized by a diffusion flame that can be arbitrarily defined by the inner flame A', which is premixed with coal and is sensitive to changes in oxygen concentration, as described above, and the auxiliary air port 30.

Since it is composed of external flame A, combustion is stable during normal combustion even if the gas components change slightly.

The size of this auxiliary air port 30 and the primary air port 18
By appropriately setting the size of the gas, it becomes possible to blow off the gas with the same oxygen concentration using the primary flame in the event of oxygen deficiency, even if the gas type is changed, such as natural gas, LP gas, or hydrogen-based gas.

It goes without saying that when changing the gas type, the nozzle diameter and gas pressure settings, which are commonly carried out, are carried out at the same time.

On the other hand, secondary flame B is not as sensitive to oxygen concentration as primary flame A,
Even after 1 flame A is blown away, 2 flames B remain.

Note that hydrogen-based gas has a much higher combustion speed than other gases, so it is necessary to devise a configuration that will easily cause blow-off at the primary flame port 17.

For example, the primary flame opening 17 may be shaped like a knife as shown in FIG. 3, or shaped like an orifice as shown in FIG. 4.

Next, the two flames B formed at the secondary flame port 14 are replaced by the one flame A.
It is preferable to leave it for a very short time of 30 to 60 seconds after it is blown away.

That is, by holding the secondary flame B, even if gas is ejected from the main burner until the first flame A is blown away and the thermocouple 24 closes the solenoid valve, it will be ignited by the second flame B, and the raw gas will be ignited. It can prevent poisoning and explosion due to spillage.

In FIG. 5, the secondary flame port 14 is made step-shaped for this purpose, and the holding ability of the two flames A is improved at the stepped portion, and in FIG. A flame impingement body 26 is provided oppositely to the secondary flame port 14 via a plurality of elastic legs 25 to prevent the two flames B from blowing away.

Furthermore, in FIGS. 7 and 8, a cooling means is provided in the outer cylinder 13 in order to prevent the inside of the outer cylinder 13 from being overheated due to the influence of the combustion heat of the main burner and deteriorating the blow-off characteristics of one flame A. Figure 7 shows a wind cylinder 27 installed outside the outer cylinder 13 to allow convection air to flow through the gap t between the two, and Figure 8 shows the outside of the outer cylinder 13 in the area where the combustion heat of the main burner does not reach. A heat radiation fin 28 is provided from the inside.

It is also conceivable that the outer cylinder 13 be made of a heat insulating material such as porcelain as shown in FIG.

In the above example, a thermocouple was used for primary flame detection, but other heat-sensitive devices such as an ion current element such as a flame rod, a temperature-resistance element such as a thermistor, a bimetal element, and a liquid-expanded heat-sensitive element may also be used. Any effect can be expected even if an oxygen sensor such as a photoresponsive element or a photosensitive element made of tin oxide that responds to the light generated from the flame of a CDS element is employed.

Furthermore, in the above embodiment, the inner cylinder 12 is made into a cylindrical shape, and the primary air port 18 is opened in the lower part at a right angle to the inner cylinder 12, and the gas nozzle 23 is exposed. 2 so that the flame has a diffusion flame that burns with a little auxiliary air.
As long as it has an outer cylinder 13 that can restrict secondary air, it is possible to use not only the above embodiment but also a burner configuration having a general mixing pipe for premixing a predetermined primary air, and use it as a pilot burner. The same effect can be obtained even if it is configured not only as a main burner but also as a main burner.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention includes an inner cylinder having a primary flame port;
a burner body consisting of an outer cylinder that is separated from the primary flame port to form a secondary flame port, and an auxiliary air port that supplies secondary air limited to the primary flame formed in the primary flame port; By providing the outer cylinder near the primary flame port, the flame can be separated from the primary flame.
This system separates and forms secondary flames, detects unstable primary flames, and performs safe operations, and has the following effects.

(1) Accurate and safe operation can be performed not only when combustion fades out, but also when the oxygen temperature in the air is low, so-called oxygen-deficient conditions.

(2) Since controlled secondary air is supplied to the primary flame, the combustion is stable even when the combustion speed of the fuel gas changes due to variations in gas components caused by seasonal fluctuations, and In the event of an abnormality, it is possible to detect the blow-off of the primary flame, and its industrial value is extremely high.

(3) Since the flame 1 is covered with an outer cylinder, it is not thermally affected by the main burner when the present invention is used as a pilot burner.

(4) By making the inner cylinder freely removable, gas conversion can be easily performed for many gas types.

(5) Furthermore, by forming the shape of one flame port into an acute angle shape or a constricted shape, one flame can be blown out more quickly when the oxygen concentration decreases.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a conventional combustion safety device, FIG. 2 is a cross-sectional view of a combustion safety device showing an embodiment of the present invention, and FIG.
Figures 4 and 4 are primary cutaway front views showing other embodiments of the inner cylinder, Figures 5 and 6 are partially cutaway front views showing other embodiments of the outer cylinder, and Figure 7 is a further cut away front view of the outer cylinder. A sectional view showing another embodiment,
FIGS. 8 and 9 are front views showing still other embodiments of the outer cylinder. 11...Burner body, 12...Inner cylinder,
13...Outer cylinder, 14...2 flame port, 1
7...1 flame port, 18...primary air port, 23...gas nozzle, 24...primary flame detection element (thermo couple), 26 ...Flame shield, 28...Radiation fin, 30...Auxiliary air port.

Claims (1)

[Scope of Claims] 1. An inner cylinder having one flame port on one side and a waste nozzle facing on the other side, and having a primary air port, and an outer cylinder having two flame ports separated from the first flame port. a burner body consisting of; an auxiliary air hole formed in the outer cylinder near the first flame port and supplying controlled secondary air; and a primary flame detector for detecting the first flame formed in the first flame port. A combustion safety device comprising an element and a valve for controlling fuel supplied to a gas nozzle by the primary flame detection element. 2. The combustion safety device according to claim 1, wherein the inner cylinder is configured to be detachable. 31. The combustion safety device according to claim 1, wherein the edge of the flame port has an acute angle. 41. The combustion safety device according to claim 1, wherein the flame port is formed in a constricted shape. 5. The combustion safety device according to claim 1, wherein the outer cylinder is made of a heat insulating material.