JP2000161654A - Combustion device by heat storage type burner and combustion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve combustion efficiency and heating capacity and hold furnace atmosphere non-oxidative by a method wherein this combustion device is a device to alternately perform fuel combustion and combustion gas exhaust of a pair of heat storage type burners, combustion is momentarily switched, and incurring of a time loss occasioned by the switching is reduced. SOLUTION: This device is constituted that at least one pair of heat storage type burners 2a and 2b provided with heat storage bodies 3a and 3b are arranged at a furnace body 1, and when fuel combustion is effected by one heat storage type burner, combustion gas in the furnace is discharged from the other heat storage type burner and the heat storage bodies are heated and combustion air is preheated by combustion gas by alternately performing fuel combustion and discharge of combustion gas by the two heat storage type burners. In this case, three-way switching valves 9a and 9b are directly integrally arranged at the backs of the heat storage bodies of the two heat storage type burners. The back of the heat storage body communicated with an air supply pipe 10 or an air exhaust pipe 12 through switch of the three-way switch valves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus and a combustion method for an industrial furnace using a regenerative burner as a heat source.

[0002]

2. Description of the Related Art As shown in FIG. 4, a combustion apparatus using a regenerative burner (also referred to as a regenerative burner) devised for energy saving in an industrial furnace is provided on a side wall of a furnace body 1 or the like. Heat storage bodies a1, a2 such as air-permeable ceramic bodies, respectively
At least a pair of burners b1 and b2 having
The supply and exhaust pipes c1 and c2 of each of the burners b1 and b2 are connected to two opposite ports of the four-way switching valve d, and the other two ports of the four-way switching valve d are connected to the intake pipe e and the exhaust pipe f. And fuel valves g1 and g2 for supplying fuel gas to the burners b1 and b2, respectively.
When the combustion air and the fuel gas are supplied to one of the burners b1 for combustion in the switching state shown in the drawing, the combustion gas is discharged from the other burner b2 through the regenerator a2, and the regenerator a2 is heated,
After the combustion state is continued for several tens of seconds to several minutes, the four-way switching valve d is switched, and the combustion air supplied to the burner b2 is preheated by passing through the regenerator a2 and is provided for combustion, The combustion gas is discharged from the burner b1 through the regenerator a1 to heat the regenerator a1.
After several minutes, the four-way switching valve d is switched to its original state,
Thus, the fuel combustion and the exhaust of the combustion gas by the two burners b1 and b2 are alternately performed, so that the regenerator always heated by the combustion gas preheats the combustion air, and therefore, a high exhaust heat recovery efficiency can be obtained. It is possible to achieve significant energy saving.

In the above-mentioned combustion apparatus, as shown in a timing chart of FIG. 5, the timing of the combustion alternation of both burners b1 and b2 (the hatched portion indicates that the combustion is being performed), the combustion alternation is temporarily performed. In both the burners b1 and b2, a period of time in which the burners are not in a combustion state occurs. In other words, when the combustion is switched by the four-way switching valve d as in the prior art, the combustion air is supplied from the four-way switching valve d during the transition period from the combustion gas discharge period to the fuel combustion period. Even if the fuel gas is supplied, the combustion gas remains in the supply / exhaust line c1 or c2 and is not burned unless the combustion gas is pushed out by the combustion air and discharged into the furnace. To prevent explosion in the furnace, the timing of opening the fuel valve g1 or g2 is delayed from the timing of switching the four-way switching valve d. Also, in the transition period from the fuel combustion period to the combustion gas discharge period, the timing for stopping the supply of the fuel gas precedes the timing for switching the four-way switching valve d.

[0004]

As described above, in the conventional combustion apparatus, in order to ensure safety, both burners b1 and b2 have to be provided with a time in which neither of them is in a combustion state.
For this reason, there was a drawback that the substantial burning time was shortened and the heating capacity was reduced. Further, if the supply of combustion air is performed in advance, there is a disadvantage that even if the air-fuel ratio is set to 1 or less, the inside of the furnace becomes so-called air-rich, the atmosphere becomes oxidizing, and the object to be heated is easily oxidized. SUMMARY OF THE INVENTION The present invention solves the above problems, improves the efficiency of combustion by a regenerative burner, and facilitates maintaining the furnace atmosphere non-oxidizing.

[0005]

In order to achieve the object, a combustion apparatus using a regenerative burner according to the present invention is provided with at least one pair of regenerative burners provided with a regenerator in a furnace body and causes one of the regenerative burners to burn fuel. The combustion gas in the furnace is discharged from the other regenerative burner when the combustion is in progress, and the regenerator is heated by the combustion gas by alternately performing the fuel combustion and the combustion gas discharge with the two regenerative burners. The three-way switching valve is directly and integrally provided behind the regenerator of both regenerative burners, and the back of the regenerator is supplied with an air supply pipe or by switching the three-way switching valve. It is characterized in that it can communicate with the exhaust pipe. Further, in the combustion method using the regenerative burner according to the present invention, at least one pair of regenerative burners each including a heat storage element is provided in a furnace body, and when fuel is burned by one regenerative burner, the other regenerative burner is used for furnace combustion. The combustion gas in the inside is discharged, and the heat storage body is heated by the combustion gas by alternately performing the fuel combustion and the combustion gas discharge by the both heat storage type burners, so that the combustion air is preheated, A three-way switching valve is directly and integrally provided behind the heat storage body of both heat storage burners, and the back of the heat storage body can be communicated with the air supply pipe or the exhaust pipe by switching the three-way switching valve, The combustion is performed by setting the air-fuel ratio of both regenerative burners to 1 or less.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. In the figure, 1 is a furnace body, 2
Reference numerals a and 2b denote a pair of regenerative burners provided on the side wall of the furnace body, and reference numerals 3a and 3b denote regenerators such as air-permeable ceramic bodies provided on the respective regenerative burners. Behind the heat storage body of each heat storage type burner, a substantially triangular valve chamber 4 is integrally formed as shown in an enlarged view in FIG. 6, a plate-shaped valve element 8 is fixedly mounted on a rotating shaft 7 inserted into the intersection of the walls of the two chambers, and the rotating shaft 7 is rotated by the operation of a solenoid (not shown) to open the valve. The body 8 constitutes three-way switching valves 9a and 9b which can rotate as shown by the arrows and close the air supply port 5 or the exhaust port 6.

An air supply pipe 10 is connected to an air supply port 5 of each of the heat storage type burners 2a and 2b, and an air supply fan 1 is connected to the air supply pipe.
1 is connected to supply combustion air, an exhaust pipe 12 is connected to the exhaust port 6, and an exhaust fan 13 capable of sucking combustion gas is connected to the end of the exhaust pipe. Reference numeral 14 denotes an ignition pilot burner, 15 denotes a fuel gas supply pipe, and 16a and 16b denote fuel valves provided to supply the fuel gas to the fuel gas supply pipe 15.

As described above, the pair of heat storage type burners 2a and 2b
When the three-way switching valves 9a and 9b are in the switching state shown in FIG.
3 is supplied to one regenerative burner 2a, and the fuel valve 16a is opened to supply fuel gas, whereby the regenerative burner 2a is brought into a combustion state. Storage burner 2 by the action of
The heat storage body 3b is heated by the exhaust heat of the combustion gas by being sucked into the heat storage body b and passing through the heat storage body 3b. When the three-way switching valves 9a and 9b are switched to the switching state shown in FIG. 2 after a certain period of time, the combustion air pumped from the air supply fan 11 is preheated by the regenerator 3b, and the fuel valve 16b
And the fuel gas is supplied to open the heat storage type burner 2b in a combustion state, and the combustion gas in the furnace is discharged through the heat storage body 3a of the heat storage type burner 2a to heat the heat storage body 3a. Become like By alternately operating the two heat storage burners 2a and 2b in this manner, the combustion air is preheated and energy saving is achieved.

In the combustion apparatus of the present invention, the three-way switching valves 9a and 9b are integrally provided behind the heat storage bodies 3a and 3b of both the heat storage type burners 2a and 2b, so that the three-way switching valves are switched. When activated, the back of the heat storage body is directly
0 or communicates with the exhaust pipe 12, so that the combustion gas does not remain in the supply / exhaust pipe as in the prior art, and the combustion can be replaced instantaneously.

In the combustion method of the present invention, the air in the furnace is set to an air-fuel ratio of 1 or less during combustion and the fuel is burned in a fuel-rich state so that the atmosphere in the furnace is non-oxidizing. In that case, there is no need to supply additional combustion air even during the transition period of combustion switching,
It becomes easy to keep the furnace atmosphere in a non-oxidized state.

[0011]

As described above, in the combustion apparatus and the combustion method according to the present invention, the three-way switching valve is directly provided integrally behind the heat storage element of the regenerative burner, and the back of the heat storage element is thereby supplied. Since the combustion switching is performed instantaneously by communicating directly with the trachea or the exhaust pipe, the time loss associated with the switching is reduced, and the combustion time of both burners can be extended.
Therefore, the combustion efficiency and the heating capacity are greatly improved. In addition, since the atmosphere in the furnace is kept non-oxidizing and the regenerative burner can be used as a heat source of the non-oxidizing atmosphere furnace, the use of the regenerative burner can be expanded and its energy can be saved. Has a beneficial effect.

[Brief description of the drawings]

FIG. 1 is a piping diagram of a combustion device using a regenerative burner according to the present invention.

FIG. 2 is an operation state diagram of FIG. 1;

FIG. 3 is a vertical sectional view of a heat storage type burner according to the present invention.

FIG. 4 is a piping diagram of a conventional regenerative burner combustion device.

FIG. 5 is a timing chart of combustion replacement of a regenerative burner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace body 2a, 2b Heat storage type burner 3a, 3b Heat storage body 4 Valve room 5 Supply port 6 Exhaust port 7 Rotating shaft 8 Valve element 9a, 9b Three-way switching valve 10 Supply pipe 12 Exhaust pipe 15 Fuel gas supply pipe 16a, 16b fuel valve

Claims (2)

[Claims] At least one pair of a regenerative burner having a regenerator is provided in a furnace body. When fuel is burned by one regenerative burner, combustion gas in the furnace is discharged from the other regenerative burner. The heat storage body is heated by the combustion gas by pre-heating the combustion air by alternately performing the fuel combustion and the combustion gas discharge in the both heat storage type burners. A three-way switching valve is directly provided integrally behind the heat storage element, and the back of the heat storage body can communicate with an air supply pipe or an exhaust pipe by switching the three-way switching valve. Combustion equipment. 2. At least one pair of regenerative burners having a regenerator is provided in a furnace body, and when fuel is burned by one regenerative burner, combustion gas in the furnace is discharged from the other regenerative burner. The heat storage body is heated by the combustion gas by pre-heating the combustion air by alternately performing the fuel combustion and the combustion gas discharge in the both heat storage type burners. A three-way switching valve is provided directly and integrally behind the heat storage body so that the back of the heat storage body can communicate with an air supply pipe or an exhaust pipe by switching the three-way switching valve. The combustion method using a regenerative burner, characterized in that the combustion temperature is set to 1 or less.