JP2002039515A - Gas burner and combustion device using gas burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas burner where reduction of NOx is enabled by increasing the air ratio of premixed gas and to provide a burner in which energy is saved by burning recirculated combustion exhaust gas by increasing air ratio using the gas burner. SOLUTION: The gas burner is structured as a fully premixed combustion type, by providing with a plurality of burner ports 8 fed with premixed gas formed by mixing fuel gas and combustion air beforehand and the burner uses the gas burner comprising a gas burner B arranged with the two rows of the burner ports 8, all of which are arrayed mutually in parallel or nearly parallel and a pair of flame holding walls 9, protruding towards the direction on the side of forming flames as viewed in the direction of the lines of the pair of the burner ports 8 with the pair of the burner ports positioned between the pair of the flame holding walls 9, and each of the pair of the rows of the burner ports 8 jets the whole of the premixed gas to the adjacent flame holding walls 9, where the combustion exhaust gas exhaust from the gas burner B is recirculated inside the combustion chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas burner having a plurality of flame ports to which a premixed gas in which a fuel gas and a combustion air are premixed is supplied, and which is constituted by a completely premixed combustion type. The present invention relates to a combustion device using the gas burner.

[0002]

2. Description of the Related Art In such a complete premixed combustion type gas burner, a configuration shown in FIG. 5 is conventionally known as a configuration in which a plurality of flame ports are arranged in a row. The conventional gas burner shown in this figure is formed by a metal pipe 7A, and has three rows of flame ports along the longitudinal direction of the pipe 7A, that is, a main flame port located at the center in the longitudinal direction of the pipe 7A. 8A and a relatively small diameter flame holding port 8B located on the left and right of the main flame opening 8A. A flame holding plate 9A is located outside the left and right flame holding ports 8B. Attached to. Then, a large amount of premixed gas ejected from the central main flame opening 8A is burned to generate a main flame, and the flame due to the combustion of the premixed gas from the left and right flame holding holes 8B is applied to each flame holding plate 9A. The main flame at the center is stuck from the left and right, and is stably burned.

[0003]

However, in the above-described conventional gas burner, the premixed gas from the main flame opening 8A is jetted upward as it is. Therefore, when the air ratio of the premixed gas is increased, the main flame opening 8A is increased. The flow rate of the premixed gas ejected from the nozzle becomes too fast, and the flame speed is lowered due to a decrease in the flame temperature due to an increase in the amount of air. There was a problem that it had to be set within the range. As described above, in the conventional gas burner, the air ratio of the premixed gas cannot be increased so much. Therefore, it is not possible to reduce NOx by reducing the flame temperature, and in a combustion device using the gas burner, If a part of the flue gas discharged from the gas burner into the combustion chamber is recirculated again into the combustion chamber, combustion becomes impossible due to a shortage of combustion air. Therefore, there is a drawback that the heat recovery rate cannot be increased and energy saving cannot be achieved by adopting the combustion exhaust gas recirculation system.

The present invention focuses on such conventional drawbacks, and aims at using a gas burner capable of reducing the NOx by increasing the air ratio of the premixed gas and using the gas burner. Accordingly, it is an object of the present invention to provide a combustion apparatus which can increase the air ratio and recirculate and burn the combustion exhaust gas, thereby saving energy and reducing NOx.

[0005]

According to a first aspect of the present invention, there is provided a fuel injection system comprising a plurality of flame openings to which a premixed gas in which a fuel gas and a combustion air are previously mixed is supplied. A gas burner configured as a mixed combustion type, wherein all of the flame ports are arranged in two rows so as to be parallel or almost parallel to each other, and when viewed in the direction in which the two rows of flame ports are arranged, the flame forming direction side Are provided so as to locate the two rows of flame ports therebetween, and each of the two rows of flame ports is provided with a premixed gas Spout to apply the whole amount.

That is, all of the plurality of flame ports to which the premixed gas of the fuel gas and the combustion air are supplied are arranged in two rows so as to be parallel or almost parallel to each other. In a direction view, a pair of flame holding walls protruding toward the flame forming direction side is provided so as to locate the two rows of flame ports therebetween, and the two rows of flame ports are adjacent to each other. Since the jetting is performed so that the entire amount of the premixed gas is applied to the flame holding wall, even if the air ratio of the premixed gas is increased, the entire amount of the premixed gas is applied to the flame holding wall, so that the premixed gas is discharged. The flow velocity is reduced to avoid flame lift. Therefore, by increasing the air ratio of the premixed gas, it is possible to reduce NOx by lowering the flame temperature, and by using such a gas burner in a combustion device, the combustion exhaust gas discharged into the combustion chamber can be reduced. Can be recirculated again into the combustion chamber, so that it is possible to reduce NOx and save energy by recovering heat of combustion exhaust gas.

According to the characteristic configuration of the present invention, since the air ratio of the premixed gas is 1.2 or less, for example, by setting the air ratio to about 1.0 to 1.2. Even if the above-described combustion exhaust gas recirculation system is adopted, good combustion can be performed, and energy can be reliably saved.

According to a third aspect of the present invention, between the two rows of the flame ports, the angle between the directions in which the premixed gas is ejected from the flame ports forming each row is determined in the direction in which the flame ports are arranged. , The premixed gas can be applied to each flame holding wall as desired, and the air ratio of the premixed gas is increased to reduce the above-mentioned NOx reduction and energy saving. It can be achieved reliably.

According to a fourth aspect of the present invention, there is provided a combustion apparatus using the gas burner according to any one of the first to third aspects, wherein the flame outlet is located in a combustion chamber. Since a burner is disposed and the combustion exhaust gas discharged from the burner into the combustion chamber is recirculated into the combustion chamber, the use of the above-described recirculation type of the combustion exhaust gas can reduce NOx and save energy. A possible combustion device can be provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas burner according to the present invention and a combustion apparatus using the gas burner will be described with reference to the drawings. As shown in FIG. 1, the gas burner B of the present invention burns a premixed gas in which a fuel gas supplied from a fuel gas supply passage 1 and a combustion air supplied from a combustion air supply passage 2 are mixed in advance. In the burner of the complete premixed combustion type, the fuel gas supply passage 1 and the combustion air supply passage 2 are connected via a venturi mixer 3 and the premixed gas mixed by the venturi mixer 3 is premixed. It is configured to be supplied to the gas burner B via the gas supply path 4. The combustion air supply path 2 is provided with a flow rate control valve 5 for adjusting the flow rate of combustion air, and the fuel gas supply path 1 is provided with a zero governor 6 for adjusting the pressure of the fuel gas to atmospheric pressure. Even when the flow rate of the combustion air is changed and adjusted within a predetermined range by the flow control valve 5, the combustion air and the fuel gas are mixed at a predetermined constant mixing ratio.

As shown in FIGS. 2 and 3, the gas burner B is formed by a metal pipe 7 having an annular cross section, and a part a on the inflow side of the premixed gas, which functions as a mixing part, and other parts. Except for a part b on the side, a part of the outer periphery of the pipe 7 is cut off in a direction orthogonal to the radial direction of the pipe 7,
A large number of flame holes 8 are drilled in a plane portion formed by the resection. In the plane part by the cut, on both sides in the longitudinal direction of the pipe 7, a metal flame holding member 9 functioning as a flame holding wall is attached by a plurality of screws 10 along the longitudinal direction of the pipe 7, Between the pair of opposed flame holding members 9, all of the large number of flame openings 8 are arranged in two rows so as to be parallel or almost parallel to each other along the longitudinal direction of the pipe 7. Then, in the pipe 7 forming the gas burner B, the end on the back side is sealed by a closing plate 12, and the premixed gas from the premixed gas supply passage 4 passes through a plurality of flame ports 8 through a mixing section a. It is configured to be spouted from.

The flames 8 arranged in two rows have an angle α of 20 degrees between the directions in which the premixed gas is ejected from the flames 8 forming each row when viewed in the direction in which the two rows of flames 8 are arranged. The flame holding member 9 which is set to fall within the range of about 40 degrees, preferably about 30 degrees, and protrudes in the flame forming direction side by the flame port 8, from the flame ports 8 in the right row The entire amount of the premixed gas ejected is applied to the right flame holding member 9, and the entire amount of the premixed gas ejected from the flame outlets 8 in the left column is applied to the left flame holding member 9. It is configured to be. That is, a pair of flame holding members that are arranged in two rows so that all of the flame ports 8 are parallel or substantially parallel to each other, and that project in the flame forming direction side when the two rows of flame ports 8 are viewed in the direction of arrangement. 9 are provided to position two rows of flame outlets 8 therebetween, each of the two rows of flame outlets 8 being:
The gas is ejected so that the entire amount of the premixed gas is applied to the adjacent flame holding member 9.

A numerical example of one example of the gas burner B having such a configuration is as follows. As the pipe 7 forming the gas burner B, various diameters D can be used. Is about 7 to 8 mm, and a part of the outer circumference of the pipe 7 is cut off so that the thinnest thickness t after cutting is about 3 to 4 mm, and the height of the flat portion formed by the cut is The flame holding member 9 having h of about 7 to 8 mm is attached. Furthermore, the angle α between the premixed gas ejection directions from the flame outlets 8 in each row is set to about 30 degrees,
Is set so as to collide near the center of the height h of the flame holding member 9 and the length L of the mixing portion a is set to L ≧ 4D. Then, when an experiment was performed using the gas burner B formed based on such numerical values, the air ratio of the premixed gas could be set in the range of 0.7 to 1.2. However, no flame lift was observed, and good combustion was continued.

A combustion device using such a gas burner B is used, for example, in a commercial gas cooker or the like, and as shown in FIG. A plurality of rice cookers 15 are arranged so as to be parallel to each other with the mouth 8 facing upward, and a rice cooker 15 is removably stored in the upper part of the combustion chamber 14. Above the combustion chamber 14, a discharge port 16 for discharging combustion exhaust gas discharged from each gas burner B into the combustion chamber 14 to the outside of the combustion chamber 14 and then circulating the exhaust gas again to the combustion chamber 14; Exhaust port 20 for discharging the gas to the outside of the combustion chamber 14
Are provided, and beside and below the combustion chamber 14,
A plurality of circulation ports 17 are provided, and the discharge port 16 and the circulation port 17 are connected to each other by a circulation path 18. A circulation fan 19 is provided in the vicinity of the discharge port 16, and the combustion exhaust gas discharged from each gas burner B into the combustion chamber 14 is burned from the plurality of circulation ports 17 through the circulation path 18. It is configured to recirculate in the chamber 14.

[Other Embodiments] (1) In the above embodiment, a circular pipe 7 is used, a part of the outer periphery of the pipe 7 is cut off to form a flat portion, and a flame holding wall is formed on the flat portion. Although the example in which the gas burner B is formed by attaching the flame holding member 9 functioning as the above is shown, the flame holding member 9 can be formed without using a pipe having a rectangular cross section or cutting off a part of the outer peripheral portion of the pipe. Various modifications can be made to the specific configuration when forming the gas burner B, such as forming the gas burner B by attaching the gas burner B.

(2) In the above embodiment, an example was shown in which the gas burner B was used for a commercial gas cooker, but in addition to the gas cooker, various ovens such as a fryer or a bread oven were used. Further, it can be used for various devices such as a drying furnace for drying a coated article such as an automobile part.

[Brief description of the drawings]

FIG. 1 is a view showing a configuration of a gas burner, (a) is a plan view, and (b) is a longitudinal side view.

FIG. 2 is a partially cutaway perspective view of a gas burner.

FIG. 3 is a view taken along a line II in FIG.

FIG. 4 is a schematic configuration diagram of a combustion device.

5A and 5B are diagrams showing a configuration of a conventional gas burner, wherein FIG. 5A is a plan view, and FIG.

[Explanation of symbols]

 8 Flame mouth 9 Flame holding wall 14 Combustion chamber B Gas burner α Angle between premixed gas ejection directions

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F23D 14/74 F23D 14/74 DF Term (Reference) 3K017 AA01 AA02 AA06 AB02 AB08 AD08 3K065 TA01 TA09 TA15 TC00 TC05 TD05 TL03

Claims (4)

[Claims] 1. A gas burner comprising a plurality of flame ports to which a premixed gas in which a fuel gas and combustion air are premixed is supplied, and configured as a completely premixed combustion type, wherein: All of them are arranged in two rows so as to be parallel or almost parallel to each other, and a pair of flame holding walls projecting toward the flame forming direction side when viewed in the direction in which the two rows of flame openings are arranged are arranged between them. A gas burner provided so as to position two rows of flame ports, wherein each of the two rows of flame ports blows out so as to apply the entire amount of the premixed gas to the adjacent flame holding wall. 2. The gas burner according to claim 1, wherein an air ratio of the premixed gas is 1.2 or less. 3. The angle between the two rows of flame outlets in the direction in which the premixed gas is ejected from the flame holes forming each row is 20 to 40 degrees as viewed in the direction in which the flame holes are arranged. Or the gas burner according to 2. 4. A combustion apparatus using the gas burner according to claim 1, wherein the burner is arranged such that the flame port is located in a combustion chamber, and the combustion is performed from the burner. A combustion device configured to recirculate flue gas discharged into a combustion chamber into the combustion chamber.