JPH08159447A - Combustion device - Google Patents

Abstract

PURPOSE: To increase the degree of mixing of fuel and air by a method wherein an opening unit is formed so as to have a slot shape while an angle for increasing the whirling force of whirling air is provided between the extension line in the lengthwise direction of the opening unit and the center line of a circular hole. CONSTITUTION: A flame-stabilizing cylinder 52 is constituted of a circular hole 54, formed around the imaginary extension line of the center line of a fuel spray nozzle 31 and the lower end opening of an inner cylinder lower part 51 is inserted thereinto, a plurality of cut-and-raised vanes 55, formed around the circular hole 54 to allow flame-stabilizing air to swirl, a flame stabilizing plate 53, having slot-shaped opening units 56 formed of the cut-and-raised vanes 55, and a flame-stabilizing cylinder peripheral wall 57, provided around the outer periphery of the flame-stabilizing plate 53. On the other hand, an angle θ for increasing the swirling force of the swirling air is provided between an extension line (a) in the lengthwise direction of slot-shaped openings 56 formed around the circular hole 54 formed on the flame-stabilizing plate 53 by the cut-and-raised vanes 55 and the center line (b) of the circular hole 54. Primary air, secondary air and whirling air, formed by the cut-and-raised vanes 55, are ventilated into the inner cylinder 5 to effect excellent combustion in the combustion device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device such as a petroleum water heater.

[0002]

2. Description of the Related Art Conventionally, there is an oil type water heater having a heat exchanger inside a casing, a combustion apparatus X connected to the upper end of the heat exchanger, and an exhaust duct connected to the lower end of the heat exchanger.

As shown in FIG. 6, the combustion apparatus X of the water heater has an inner cylinder portion 100 surrounding a combustion flame of atomized fuel.

The inner cylinder portion 100 is a substantially cylindrical inner cylinder body 11 that concentrically surrounds the fuel spray nozzles 300 at regular intervals.
0 and an inner cylinder lower part 120 that is continuously connected to the lower end of the inner cylinder main body 110 and has a diameter that gradually decreases downward, and at the lower end of the inner cylinder lower part 120, a cylindrical flame holding cylinder 130 is formed. It is configured by connecting them.

The flame holding cylinder 130 has a circular hole 140 formed around the virtual extension line of the central axis of the fuel spray nozzle 300 by inserting the lower end opening of the inner cylinder lower part 120, as shown in FIG. A flame holding plate 170 having an opening 160 formed by a plurality of cut-and-raised blades 150 formed radially from the periphery of the hole 140 toward the outside, and a flame holding plate 170 hung vertically from the outer circumference of the flame holding plate 170 to generate secondary air. The flame holding cylinder peripheral wall 180 is formed with a hole 400.

When the combustion apparatus X having the above-mentioned structure is operated to burn the primary air, the primary air is introduced into the flame holding cylinder 130 through the circular hole 140, and the primary air is maintained through the opening 160 provided near the fuel spray nozzle 300. Let it flow into the flame tube 130 and
Swirling air is generated by the cut-and-raised blades 150 when passing through 160, and the swirling force promotes mixing of fuel and air.

In FIG. 6, reference numeral 200 denotes a fuel stirring plate, which temporarily retains the fuel that cannot be sufficiently mixed by the secondary air from the secondary air hole 400 to promote the mixing of oil and air. It is for the purpose of planning.

[0008]

However, the structure of the combustion apparatus X having the above structure still has the following problems.

That is, if the amount of secondary air is increased to increase the degree of mixing of air in order to improve the combustion performance in the case of combustion with a small amount of oil, it leads to cooling of the flame and an effective means. Therefore, as described above, it was considered to increase swirling air by the cut-and-raised blades 150 formed near the fuel spray nozzle 300 and to promote mixing of fuel and air by the swirling force.

For that purpose, since the fuel spray nozzle 300 is located at the center of the flame holding plate 170, it is necessary to make the circular hole 140 as small as possible to bring the swirling air closer to the spray fuel. There is a limit to the size of the circular hole 140 due to the balance of the injection angle and the disposition position of the spark plug and the like.

In addition, in the opening 160 formed as shown in FIG. 8, the opening base 190 (shaded portion) that influences the swirling force of the air flowing in from the circular hole 140 is small, and the swirling air is prevented from flowing through the circular hole 140. It was difficult to get closer to the center. Therefore, the degree of mixing of fuel and air was naturally limited.

According to the present invention, there is provided a combustion device capable of spreading the swirling air to the center of the circular hole 140 without increasing the size of the circular hole 140 and increasing the degree of mixing of fuel and air. It is intended to be provided.

[0013]

According to the present invention, a flame holding plate installed in front of a fuel spray nozzle is provided with a circular hole around a virtual extension line of a central axis of the fuel spray nozzle, and a peripheral edge of the circular hole. In the combustion device in which a plurality of cut-and-raised blades are radially formed from the outer side to the outside, and air is made to flow out from an opening formed by the cut-and-raised blades to generate swirling air, the opening is formed in a long hole shape. In addition, the present invention relates to a combustion device characterized in that an angle for strengthening the swirling force of the swirling air is provided between the extension line in the longitudinal direction of the opening and the center line of the circular hole.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an overall explanatory view of a petroleum water heater having a combustion device according to this embodiment, and FIG. 2 is an explanatory view of the combustion device in a sectional view.

As shown in FIG. 1, a petroleum water heater A according to this embodiment has a heat exchanger 1, a combustion device B connected to the upper end of the heat exchanger 1, and a lower end of the heat exchanger 1. The connected exhaust duct 2 is housed and arranged inside the casing C.

As shown in FIG. 2, the combustion apparatus B includes a combustion section 3 and a blower section 4, and the blower section 4 has a fan (not shown) driven by a motor 40 in a fan casing 41. The air outlet of the fan casing 41 is communicatively connected to the combustion unit 3. Moreover, the structure of the combustion part 3 is as follows.

That is, the combustion section 3 includes a fuel spray nozzle 31 for injecting fuel downward, an ignition plug 32 and a flame detector 33 arranged in parallel with the nozzle 31, an inner cylinder section 5 surrounding them. A primary outer cylinder 6 that surrounds the inner cylinder portion 5 at a constant distance and surrounds it; a fuel stirring plate 7 disposed below the inner cylinder portion 5; and the inner cylinder portion 5 and the primary outer cylinder 6. It is provided with an air chamber 8 formed between them and having an opening formed at the upper end in communication with the fan casing 41, and a blower control unit 9 arranged in the air chamber 8.

The inner cylinder portion 5 is connected to an inner cylinder body 50 that concentrically surrounds the fuel spray nozzle 31 at a constant interval and a lower end of the inner cylinder body 50, and the inner cylinder body 5 is gradually contracted downward. It is composed of a diametrically lower inner cylinder lower portion 51 and a cylindrical flame holding cylinder 52 which is connected to the lower end of the inner cylinder lower portion 51.

Further, an air hole 50a is formed in the inner cylinder body 50, and the air chamber 8 and the inner cylinder body 50 are inserted through the air hole 50a.
To communicate with the inside of the to form a primary air flow path.

The flame holding cylinder 52 is the gist of the present invention, and the lower end opening of the inner cylinder lower portion 51 is inserted, and the fuel spray nozzle 31
A circular hole 54 formed around the virtual extension line of the central axis of the cut-and-raised blade 55 for swirling flame-holding air formed around the circular hole 54, and an opening formed by the cut-and-raised blade 55
The flame holding plate 53 having 56 and a flame holding cylinder peripheral wall 57 extending from the outer circumference of the flame holding plate 53.

Then, as shown in FIG. 3, the air flowing through the primary air flow path is made to flow into the flame holding cylinder 52 through the opening 56, and is swirled by the cut-and-raised blades 55 when passing through the opening 56. f3, and the swirling force is used to promote the mixing of fuel and air.

In addition, the flame holding cylinder peripheral wall 57 is first and vertically arranged in two rows.
The second air holes 57a, 57b are formed, and the first and second air holes 57a, 57b are formed.
The air chamber 8 and the inside of the flame holding cylinder 52 are communicated with each other via 57b to form a secondary air flow path for flowing the secondary air f2.

As shown in FIG. 2, the blower control unit 9 has a function of controlling the amount of blown air into the inner cylindrical portion 5,
A partition wall 90 is provided inside the air chamber 8 to form a blast control space 10, and the blast control space 10 is further divided into an upper space 10a and a lower space 10b, and an upper end opening 91 formed in the upper space 10a. And a lower end opening 92, and a primary side opening 93 juxtaposed to the lower end opening 92, and a damper mechanism 94 for opening and closing the upper end opening 91 and the lower end opening 92 is arranged.

The damper mechanism 94 comprises an upper damper 94a and a lower damper 94b which are interlockingly connected to each other via an interlocking portion 95. The interlocking portion 95 is provided with a long hole 96 for opening the upper damper 94a. The lower damper 94b is opened later.

That is, in the initial stage of combustion with a small amount of oil, only the upper damper 94a is opened, and the primary air f1 is flown into the fan casing 41 → upper end opening 91 → air hole 50a → inside the inner cylinder body 50 and the primary air flow path. From the circular hole 54 of the flame holding plate 53
The swirling air f3 is generated by allowing the air to flow in and passing through the opening 56 formed by the cut-and-raised blade 55. At the same time, the first air hole 57a of the flame retaining cylinder peripheral wall 57.
Also, it is designed to slightly flow into the flame stabilizing cylinder 52.

Then, as the combustion progresses, the opening of the upper damper 94a is increased to increase the entire blown air volume, and the lower damper 94b is opened to add the secondary air f2 to the primary air f1 and the upper end opening 91 → the lower end opening. 92 → second air hole 57b → flows to the inside of the flame holding cylinder 52 also to the secondary air flow path so that the fuel and the air are sufficiently mixed as the amount of air blown according to the fuel.

As described above, the blower control unit 9 has a damper mechanism.
The upper damper 94a of 94 controls the overall air flow rate, and the lower damper 94b controls the air flow rate to the secondary air flow path.

However, the first
The secondary air from the second air holes 57a and 57b may not be able to sufficiently mix the fuel and air. Therefore, the above-described fuel stirring plate 7 is formed below the inner cylindrical portion 5, that is, as shown in FIG. It is arranged in a curved shape, and the fuel is temporarily retained in the fuel stirring plate 7 to promote mixing of the fuel and air.

In the combustion apparatus B having the structure described above, the gist of the present invention is that the opening 56 formed by the cut-and-raised blade 55 is elongated around the circular hole 54 formed in the flame holding plate 53. It is formed in a hole shape, and an angle θ for strengthening the swirling force of the swirling air f3 is provided between the extension line a in the longitudinal direction of the opening 56 and the center line b of the circular hole 54.

That is, in order to perform good combustion in the combustion apparatus B, as shown in FIG. 3, the primary / secondary air f1 and f2 from the primary air flow path and the secondary air flow path, and the cut-and-raised blade 55. The swirling air f3 from the opening 56 formed by is blown into the inner cylindrical portion 5.

In particular, when burning a small amount of oil, the combustion efficiency can be improved by making the swirling air f3 sent into the flame holding cylinder 52 effectively spread over the atomized fuel.

Therefore, as shown in FIG. 4, eight openings 56 radially formed outward from the peripheral edge of the circular hole 54 are formed in a long hole shape, and the longitudinal axis a of the opening 56 is formed. And circular hole 54
An angle θ for forming a swirling flow is provided between the opening base 58 and the center line b of the opening 56, and the opening base 58 has a substantially triangular shape and is formed on the circular hole 54 side of the opening 56.
(Refer to FIG. 5), the extension line a in the longitudinal direction of the opening 56 and the circular hole
The center line b of 54 is larger than that of the line 54 (see FIG. 8). The angle θ for forming the swirling flow is 15 ° ~
It has been experimentally found that the 25 ° range is optimal.

The opening base 58 is formed from the circular hole 54 to the flame holding cylinder 52.
It is known that it affects the swirling of the air that flows in, and by making it larger, the air that flows in from the opening base 58 is cut and raised, and the swirling force received by the blades 55 increases, and the air that flows in from the circular hole 54 flows in. A larger swirling force can also be applied to the primary air f1 that operates.

Further, the oil particles sprayed from the fuel spray nozzle 31 are swirled in a wide range by the primary air f1 to which swirling force is applied, and the effective area in contact with the swirling air f3 is increased, resulting in a flame. The swirling force of the fuel cell is also increased, the mixing of the fuel and the air is improved, and a wide combustion range can be obtained.

Therefore, even in the case of a small amount of oil, the combustion state becomes good and stable combustion is achieved, and CO and smoke can be reduced.

Thus, the angle θ for forming the swirling flow is formed between the extension line a of the opening 56 in the longitudinal direction and the center line b of the circular hole 54.
By providing the swirl air f3 from the opening 56,
The swirling force can also be applied to the primary air f1 flowing into the flame holding cylinder 52 from 54, and as described above, stable combustion at the time of a small amount of oil can be obtained.

In this embodiment, the cut and raised blades are
Although 55 and eight openings 56 are formed, the number is not limited.

[0039]

According to the present invention, a circular hole is formed in the flame holding plate installed in front of the fuel spray nozzle around the virtual extension line of the central axis of the fuel spray nozzle, and the circular hole is directed outward from the peripheral edge of the circular hole. A plurality of cut-and-raised blades are radially formed, and in the combustion device in which air is discharged from an opening formed by the cut-and-raised blades to generate swirling air, the opening is formed in a long hole shape, and By providing an angle between the extension of the opening in the longitudinal direction and the center line of the circular hole, the angle for strengthening the swirling force of the swirling air provides the following effects.

The swirling force that the inflowing air receives by the cut-and-raised blades increases, and a large swirling force can be given to the primary air that flows in from the circular hole.

The oil particles sprayed from the fuel spray nozzle are swirled in a wide range by the primary air to which swirling force is applied, and the effective area in contact with the swirling air is increased, resulting in the swirling force of the flame. As a result, the mixture of fuel and air becomes better, and a wide combustion range can be obtained.

Therefore, even when the amount of oil is small, the combustion state becomes good and stable combustion is achieved, and CO and smoke can be reduced.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of a petroleum water heater including a combustion device according to the present invention.

FIG. 2 is an explanatory view from a cross-sectional view of a combustion device of the water heater.

FIG. 3 is an explanatory diagram showing the flow of air in the combustion device.

FIG. 4 is an explanatory view showing a flame holding plate of the combustion device.

FIG. 5 is a partially enlarged view of the main part.

FIG. 6 is an explanatory view showing a conventional combustion device.

FIG. 7 is an explanatory view showing a flame holding plate of the combustion device.

FIG. 8 is a partially enlarged view of the flame holding plate.

[Explanation of symbols]

 a Extension line b Center line B Combustion device θ Angle for swirling flow formation 5 Inner cylinder 31 Fuel spray nozzle 52 Flame holder 53 Flame holding plate 54 Circular hole 55 Cut-and-raised blade 56 Opening

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Koji Koseki 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd. (72) Shinya Ohira 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Issue Nihon Yupro Co., Ltd. (72) Inventor Masanao Hattori 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture Nihon Yupro Co., Ltd. (72) Nobuhisa Sasaki 43-1 Uozakihama-cho, Higashinada-ku, Kobe City, Hyogo Prefecture Issue Nihon Yupro Co., Ltd.

Claims (1)

[Claims] 1. A flame holding plate (53) installed in front of the fuel spray nozzle (31) is formed with a circular hole (54) around a virtual extension line of the central axis of the fuel spray nozzle (31). An opening formed by radially forming a plurality of cut-and-raised blades (55) from the periphery of the circular hole (54) toward the outside and forming the cut-and-raised blades (55).
In a combustion device in which air is discharged from (56) to generate swirling air (f3), the opening (56) is formed in a long hole shape, and the opening (5) is formed.
Between the extension line (a) in the longitudinal direction of (6) and the center line (b) of the circular hole (54), an angle (θ) for strengthening the swirling force of the swirling air (f3) must be provided. Characteristic combustion device.