JP3499963B2 - Regenerative alternating burner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative alternating combustion burner used for a metal heating furnace or the like. 2. Description of the Related Art FIG . 5 shows a conventional regenerative alternating combustion burner of this type, in which a fuel supply passage 2 is provided at a central portion in a cylindrical main body 1 of the burner, and a cylindrical main body 1 is provided. One or more ventilation passages 3a, 3b are provided on the left and right sides of the inside, and combustion air is alternately supplied from the left and right ventilation passages 3a, 3b into the furnace, and the combustion air is supplied from the fuel supply passage 2 by the air. In addition to burning the fuel, the exhaust gas in the furnace is sucked from the ventilation passages 3b and 3a on the other side, and the ventilation passages 3a and 3b are connected to the heat recovery chamber 4 filled with the heat storage material, respectively. Is to preheat the air to be supplied next by the heat recovered from the furnace. Normally, two alternating combustion burners installed at two places on the furnace wall are integrated into one, and a relatively small industrial burner is used. It has a compact and inexpensive structure suitable for a furnace. [0003] However, this type of furnace has a problem in that the amount of NOx generated is large due to the high temperature of the preheated air. The distance from the outlet was large, so that the combustion air and the exhaust gas in the furnace were sufficiently mixed and then brought into contact with the fuel gas.However, there was a problem that the burner became large, and the combustion speed was set as slowly as possible. Therefore, there was a problem that the length of the flame became long and it was not possible to install it in a small furnace. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a burner of this type having a low NOx and a short flame length. According to the present invention, as shown in FIG. 1, ventilation passages 3a and 3b are provided on the left and right sides of a fuel supply passage 2 provided at a central portion in a burner main body 1. Combustion air is supplied into the furnace from one of the ventilation paths 3a, and high-temperature exhaust gas in the furnace is sucked from the ventilation furnace 3b on the other side.
a, 3b are alternately switched between the intake and exhaust, and
In the regenerative alternating combustion burner in which the combustion air is preheated by the heat recovered from the exhaust gas in the regenerator filling chamber 4 connected to the a and 3b, the front ends of the ventilation passages 3a and 3b are formed on the inner wall of the furnace. In addition to the openings at the rear end surfaces of the left and right recesses 5a and 5b, a communication path 6 for communicating the rear ends of the two recesses 5a and 5b is provided, and the front end openings of both ventilation paths 3a and 3b are further narrowed. With the ejector 7 formed, the exhaust side recess 5 is formed.
from b to supply side recess 5a sucks a portion of the exhaust, so as to inject is mixed with the combustion air into the furnace, the fuel supply passage 2
Are two fuel supply pipes whose tip nozzles 2n are inclined left and right.
2a and 2b . [0005] According to the above-described structure, since the combustion air that burns in contact with the fuel gas in the furnace is partially mixed in advance with the exhaust gas to lower the oxygen concentration, the flame temperature is suppressed. Been N
Since the Ox generation rate can be reduced and the combustion air and exhaust do not need to be mixed in the furnace as in the conventional case, the tip nozzle 2n of the fuel supply passage 2 is inclined toward the combustion air to reduce the flame length. It is also possible to make it shorter and make the furnace smaller. Further, since the fuel outlet and the combustion air outlet can be provided close to each other, the burner can be downsized. FIG. 1 is a longitudinal sectional view showing an embodiment of a regenerative alternating combustion burner according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view taken along line XX of FIG. The fuel supply passage 2 provided at the center in the main body 1 is composed of two fuel supply pipes 2a and 2b, and ventilation passages 3a and 3b are provided on the left and right so as to sandwich the fuel supply passage 2. A heat storage material filling chamber 4 is interposed in each of the ventilation paths 3a and 3b, and the heat storage material filling chamber 4 is filled with, for example, small ceramic balls (diameter of 10 to 20 mm) as heat storage materials. Actually, as shown in FIG. 2, a pilot fuel supply pipe 8 is housed and supported in a pilot air supply pipe 9 provided at the center of the burner main body 1 together with the two fuel supply pipes 2a and 2b. .
Reference numeral 10 denotes a flame holding plate which also serves as a tube support frame. The front ends of the ventilation passages 3a, 3b are open to the rear end surfaces of the left and right recesses 5a, 5b formed on the inner wall of the furnace. In the present embodiment, the ejector 7 is formed by forming two circular openings at the tip of each of the ventilation paths 3a and 3b. However, the ejector 7 may of course be one. Further, both recesses 5a, 5
b is provided with a communication path 6 for communicating the rear ends thereof, and the momentum of the combustion air passing through the ejector 7
A part of the exhaust gas is sucked from the exhaust-side recess 5b to the supply-side recess 5a, mixed with the combustion air in the recess 5a, and injected into the furnace. FIG . 4 shows a piping diagram of the burner shown in FIG. 1, in which an air supply blower 11 and an exhaust blower 12 are connected to left and right ventilation passages 3a and 3b via a four-way valve 13, and the four-way valve 13 is switched alternately supplied combustion air to one air passage 3a, the other air passage 3b are adapted to the furnace exhaust gas is sucked, fuel switching in synchronization with the four-way valve 13 The three-way valve 14 is alternately switched so that fuel is always supplied to the fuel supply pipes 2a and 2b on the combustion air supply side. The fuel gas and the combustion air for the pilot are always supplied until the inside of the furnace reaches the fuel ignition temperature, and after the fuel ignition temperature is reached, only the air is supplied for cooling the fuel supply pipes 2a and 2b. It has become.

[Brief description of the drawings] FIG. 1 is a longitudinal sectional view of one embodiment of the present invention. FIG. 2 is a front view of the same. FIG. 3 is a sectional view taken along the line XX of FIG. 1; FIG. 4 is a schematic piping system diagram of the above. FIG. 5 is a longitudinal sectional view of a conventional example. [Explanation of symbols] 1 Burner body 2 Fuel supply path 2a, 2b fuel supply pipe 2n tip nozzle 3a, 3b air passage 4 Thermal storage unit filling room 5a, 5b recess 6 way of connection 7 Ejector 8 Pilot fuel supply pipe 9 Pilot air supply pipe 10 Pipe support frame and flame holding plate 11 Air supply blower 12 Exhaust blower 13 Four-way valve 14 Three-way valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-10002 (JP, A) JP-A-55-123909 (JP, A) JP-A-6-46138 (JP, U) JP-A-59-123 186610 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23L 15/02 F23C 11/00 318 F23C 11/00 ZAB F23L 1/00

Claims (1)

(57) [Claims] [Claim 1] Vent passages are provided on the left and right sides of a fuel supply passage provided in a central portion in a burner main body, and combustion air is supplied into the furnace from one of the two vent passages. At the same time, the high-temperature exhaust gas in the furnace is sucked from the other air passage, and the intake air and the exhaust gas are alternately switched between the two air passages, and the heat is recovered from the exhaust gas in the regenerator filling chambers connected to the respective air passages. In the regenerative alternating combustion burner that preheats the air, the front ends of the ventilation paths are opened at the rear end surfaces of the left and right recesses formed on the inner wall of the furnace, and the rear ends of the two recesses are separated from each other. A communication path for communication is provided, and a part of the exhaust gas is sucked from the exhaust side recess to the combustion air side recess by an ejector formed by narrowing the front end openings of both ventilation paths, mixed with the combustion air, and so as to inject into the tip nozzle the fuel supply passage is inclined to the left and right
A regenerative alternating combustion burner composed of three fuel supply pipes .