JPH08166123A - Industrial furnace, burner for heat storage combustion and combustion method for the industrial furnace - Google Patents

Abstract

PURPOSE: To suppress the amounts of CO2 and NOx generated during combustion by fixing a burner tile having a air supply/exhaust surface with a plurality of air holes so arranged thereon as to switch between supply and exhaust, a protruded part projecting from the air supply/exhaust surface and a fuel releasing surface formed from the inside to tip of the protruded part in a furnace body. CONSTITUTION: An industrial furnace and a burner for heat storage combustion comprise a burner tile 22 through which is inserted a fuel jetting nozzle 20, a heat storage body 30 separated into a plurality of parts, for example, with a partition 31 surrounding the fuel jetting nozzle 20 and a changeover mechanism 40 which is arranged at one end in the axial direction of the heat storage body 30 and has an air supply/ exhaust partition wall 41, an opening part 42 for feed air ventilation on one side of the partition wall 41 and an opening 43 for exhaust ventilation on the other side thereof. The burner tile 22 has an air supply/exhaust surface 23 with a plurality of air holes 26 so arranged thereon as to switch between supply and exhaust, a protruded part 24 projecting into the furnace from the air supply/exhaust surface 23 and a fuel releasing surface 25 which is formed from the inside to tip of the protruded part 24 to release a fuel/primary air mixture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to supplying heat to a heat storage body which stores heat of exhaust gas in a heat storage body and stores heat of exhaust gas in the heat storage body to alternately switch between air supply and exhaust gas flow. TECHNICAL FIELD The present invention relates to an industrial furnace that performs heat storage combustion that warms up the heat, a burner for the heat storage combustion thereof, and a combustion method of the industrial furnace.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 5-256423 discloses an alternate switching burner for combustion. Here, at the tip of the burner, the fuel injection surface and the air supply / exhaust surface where the vent holes for supplying / exhausting air are opened are on the same plane orthogonal to the burner axis.

[0003]

However, when combustion is performed with a conventional burner, CO (carbon monoxide) and NO _{x in} exhaust gas are discharged.
In an amount large of (nitrogen oxides), or can not be subjected to practical use, or it may before the air release CO, NO _X reduction processing is required. There is also a problem that it is difficult for the flame to reach the back of the furnace. The purpose of the present invention is
An object of the present invention is to provide an industrial furnace in which the amount of O and NO _X produced can be suppressed and the flame reaches the depth of the furnace, a burner for heat storage combustion, and a combustion method for the industrial furnace.

[0004]

[Means for Solving the Problems] The present invention for achieving the above object is as follows. (1) Air supply / exhaust surface having a plurality of vent holes for switching supply / exhaust, a protrusion protruding from the air supply / exhaust surface, and fuel release for releasing injected fuel formed from the inside to the tip of the protrusion. An industrial furnace having a burner tile having a surface, the burner tile being fixed to a furnace body. (2) The industrial furnace according to (1), wherein the fuel release surface is formed so as to widen toward the tip of the protrusion. (3) The industrial furnace according to (1), wherein a guide groove that is concentric with the vent hole and extends in the axial direction is formed on an outer peripheral side portion of the protruding portion. (4) The industrial furnace according to (1), wherein an air nozzle separator is formed on the air supply / exhaust surface between the ventilation holes so as to project in the projecting direction of the projecting portion. (5) The industrial furnace according to (1), wherein the vent hole is narrowed as it approaches the air supply / exhaust surface, and the vent hole center is closer to the axial core side of the protrusion as it approaches the air supply / exhaust surface. (6) The vent hole and the fuel release surface are formed in a burner tile, and a primary (pilot) air supply pipe is connected to the fuel release surface and a fuel injection nozzle is disposed inside the pipe to switch between supply and discharge. The industrial furnace according to (1), wherein a switching mechanism of a rotary disk switching type is provided, and the fuel injection nozzle is rotatable in accordance with the rotation of the rotary disk. (7) A straight combustion auxiliary combustion cylinder that surrounds the plurality of vent holes from the outer peripheral side and extends axially concentrically with the projection from the tip of the projection to a position forward of the projection. Industrial furnace. (8) There is further provided a cylindrical auxiliary combustion cylinder that surrounds the plurality of vent holes from the outer peripheral side and extends concentrically with the protrusion in the axial direction from the tip of the protrusion to a position forward of the protrusion. Then, an exhaust gas return hole was provided at the rear end of the auxiliary combustion cylinder (1).
Industrial furnace described. (9) On the air supply / exhaust surface, an air nozzle separator that protrudes in the protruding direction of the protrusion is formed between the ventilation holes, and the protrusion having the guide groove is surrounded from the outer peripheral side and the air nozzle separator is provided. (3) The industrial furnace as set forth in (3), further comprising a tubular auxiliary combustion tube that extends axially from the front end of the front end of the protrusion to the front position from the front end of the protrusion. (10) The industrial furnace according to (1), wherein the inner surface of the downstream end of the vent hole and the outer surface of the protrusion are separated from each other in the radial direction of the burner tile. (11) The ventilation hole has a first portion located on the downstream side in the supply air flow direction and a second portion connected to the first portion from the upstream side in the supply air flow direction. Of the second part is inclined at a first angle in a direction in which the axis of the second part approaches the extension of the protruding part axis, and the inner surface of the second part on the side closer to the burner tile axis is the The industrial furnace according to (1), wherein the industrial furnace is inclined at a second angle larger than the first angle in a direction opposite to the inclination direction of the first portion. (12) The ventilation hole has a shape obtained by cutting a cylindrical nozzle with a plane that extends obliquely, and the plane is formed in a portion of the inner surface of the ventilation hole that is far from the burner tile axis, and is in the downstream direction. The industrial furnace according to (1), wherein the industrial furnace is inclined toward the direction toward the extension of the protrusion axis. (13) The burner tile is provided with a sub-ventilation hole that is opened in the tip end surface of the protrusion and can supply a part of the air supply passing through the ventilator to the front of the tip end surface of the protrusion part. (1) The industrial furnace described in (1). (14) The industrial furnace is a melting furnace, a sintering furnace, a preheating furnace,
Soaking furnace, forging furnace, heating furnace, annealing furnace, tempering furnace, plating furnace, drying furnace, tempering furnace, quenching furnace, tempering furnace, redox furnace, firing furnace, baking furnace, roasting furnace, melting and holding Furnace, front furnace, crucible furnace, homogenizing furnace, aging furnace, reaction furnace, distillation furnace, ladle drying preheating furnace, mold firing preheating furnace, normalizing furnace, brazing furnace, carburizing furnace, coating drying furnace, holding furnace The industrial furnace according to (1), which is any one of a nitriding furnace, a salt bath furnace, a glass melting furnace, a boiler including a power generation boiler, an incinerator including a refuse incinerator, and a water heater. (15) Fuel supply / exhaust surface having a plurality of vent holes for switching supply / discharge, a protrusion protruding from the air supply / exhaust surface, and fuel release for releasing injected fuel formed from the inside to the tip of the protrusion. A burner for heat storage combustion having a surface. (16) The burner for heat storage combustion according to (15), wherein the fuel release surface is formed to widen toward the tip of the protrusion. (17) The heat storage combustion burner according to (15), wherein a guide groove that is concentric with the vent hole and extends in the axial direction is formed on an outer peripheral side portion of the protruding portion. (18) On the air supply / exhaust surface, at a portion between the ventilation holes,
(15) The burner for heat storage combustion according to (15), wherein an air nozzle separator protruding in the protruding direction of the protruding portion is formed. (19) The vent hole is narrowed toward the air supply / exhaust surface,
The heat storage combustion burner according to (15), wherein the vent hole center is closer to the axial center side of the projecting portion as it approaches the air supply / exhaust surface. (20) The vent hole and the fuel release surface are formed in a burner tile, the fuel release surface is connected to a primary pilot air supply pipe, and a fuel injection nozzle is disposed inside the pipe to rotate the supply / discharge switching. (15) The burner for heat storage combustion according to (15), wherein a disc switching type switching mechanism is provided, and the fuel injection nozzle is rotatable according to the rotation of the rotating disc. (21) A sub-combustion cylinder having a right cylindrical shape is further provided that surrounds the plurality of ventilation holes from the outer peripheral side and extends concentrically with the projecting portion in the axial direction to a position forward of the tip of the projecting portion.
Burner for heat storage combustion described. (22) There is further provided a cylindrical auxiliary combustion cylinder that surrounds the plurality of vent holes from the outer peripheral side and extends concentrically with the projecting portion in the axial direction from the tip of the projecting portion to a position ahead of the projecting portion. Then, an exhaust gas return hole was provided at the rear end of the auxiliary combustion cylinder (1
The burner for heat storage combustion according to 5). (23) On the air supply / exhaust surface, at a site between the ventilation holes,
An air nozzle separator protruding in the protruding direction of the protruding portion is formed, the protruding portion having the guide groove is surrounded from the outer peripheral side, and the front end of the air nozzle separator is concentric with the protruding portion in the axial direction of the protruding portion. The heat storage combustion burner according to (17), further including a tubular auxiliary combustion tube extending from the tip to a position forward. (24) The heat storage combustion burner according to (15), wherein the inner surface of the downstream end of the vent hole and the outer surface of the protrusion are separated from each other in the burner tile radial direction. (25) The vent has a first portion located on the downstream side in the air supply flow direction and a second portion connected to the first portion from the upstream side in the air supply flow direction. Of the second part is inclined at a first angle in a direction in which the axis of the second part approaches the extension of the protruding part axis, and the inner surface of the second part on the side closer to the burner tile axis is the The burner for heat storage combustion according to (15), wherein the burner is inclined at a second angle larger than the first angle in a direction opposite to the inclination direction of the first portion. (26) The ventilation hole has a shape obtained by cutting a cylindrical nozzle with a plane that extends obliquely, and the plane is formed in a portion of the inner surface of the ventilation hole that is far from the burner tile axis, and is in the downstream direction. The burner for heat storage combustion according to (15), wherein the burner for heat storage combustion is inclined toward a direction approaching the extension of the axis of the protrusion. (27) The burner tile is provided with a sub-ventilation hole which is opened in the tip end surface of the protrusion and can supply a part of the air supply passing through the ventilator in front of the tip end surface of the protrusion part. (15) The burner for heat storage combustion according to (15). (28) Supply air is supplied to the inside of the furnace through a ventilation hole functioning as a supply hole, out of a plurality of ventilation holes formed on the supply / exhaust surface, the supply / exhaust surface being forward from the supply / exhaust surface. The exhaust gas in the furnace is entrained in the flow of the supply air while flowing to the tip of the projection along the side surface of the projection part that protrudes to circulate a part of the exhaust gas in the furnace in the furnace, When a flow with a part of the exhaust gas in the furnace entrained in the supply air flows to the tip of the protrusion, the mixture is mixed with the flow of fuel released from the fuel opening surface formed inside the protrusion. A combustion method for an industrial furnace comprising the steps of flowing fuel in front of a protrusion and forming a combustion region extending in the depth direction of the furnace to burn fuel. (29) The method further includes the step of discharging the exhaust gas burned in the furnace to the outside of the furnace through a vent hole that functions as an exhaust hole among the plurality of vent holes that can be switched between supply and discharge, and in the discharging step, the fuel is released. A short circuit of the fuel released from the surface into the furnace to the vent hole is suppressed by the fuel release surface tip being separated from the air supply / exhaust surface by the length of the protrusion,
(28) The method for burning an industrial furnace according to the above item.

In order to improve the ignition stability at low temperature, the air supply nozzle and the fuel nozzle may be arranged close to each other with a small distance therebetween. However, there is a problem that the amount of NOx increases due to a strong combustion reaction when the exhaust gas in the furnace is weakly recirculated and the temperature is high. Industrial furnace of the above (1), burner for heat storage combustion of the above (15), (28), (29)
In the combustion method of the industrial furnace, the fuel release surface is formed on the projecting portion protruding from the air supply / exhaust surface, so that the fuel released from the fuel open surface is exhausted from the vent holes that open on the air supply / exhaust surface. It is possible to prevent the exhaust gas from flowing into the vent hole functioning as a hole (fuel is short-circuited to the exhaust vent hole and flows). As a result, incomplete combustion of fuel that occurs when the fuel is entrained in the exhaust gas and generation of CO due to the incomplete combustion are suppressed. Furthermore, the axial projection of the protruding portion causes the supply air to enclose a part of the exhaust gas in the furnace and then encounter the fuel. As a result, the exhaust gas in the furnace circulates strongly and combustion becomes slow combustion. Generation can be suppressed. Further, due to the slower combustion, the combustion region (temperature field) extends longer toward the back of the furnace and the temperature of the combustion region is averaged.
Therefore, it is possible to raise the temperature of the entire combustion region to near the allowable temperature as compared with the conventional combustion region where the temperature difference is large,
As a result, the average heat flux can be increased, and highly efficient heat transfer (radiative heat transfer can be greatly improved) becomes possible. When achieving the same heat transfer amount, the furnace body is made compact, space efficiency is improved, and initial cost is reduced. It comes off. Further, by averaging the combustion region temperature, it is possible to avoid locally raising the temperature of the furnace wall, and thus to prolong the life of the furnace body, reduce the maintenance cost, and reduce the initial cost. further,
Due to the slow combustion, the combustion noise is also reduced. Above (2)
In the industrial furnace of (1) and the burner for heat storage and combustion of (16) above, since the fuel open surface is widened toward the tip of the protruding portion, the concomitant property of the fuel to the supply air flow is increased. Conversely, the entrainment of fuel in the exhaust stream is suppressed. If the fuel release surface is a surface orthogonal to the axis of the protruding portion, the fuel can move to the exhaust side along the orthogonal surface when drawn by the exhaust gas, but it is composed of a taper or a flared surface such as an R surface. In this case, the surface acts as a wall that prevents the fuel from moving to the exhaust side. By suppressing the entrainment of fuel into the exhaust gas, the production of CO is further suppressed. In the industrial furnace of (3) above and the heat storage and combustion burner of (17) above, since there is a guide groove that extends in the axial direction on the side surface of the protruding portion, it functions as an air supply hole of the ventilation holes opened on the air supply and exhaust surface. At least a part of the supply air flowing out from the vent hole flowing through the guide groove flows. Since the flow of the supply air through the guide groove has a strong directivity and a high flow velocity, the flow of the fuel is entrained, the fuel flow is suppressed from being caught in the exhaust gas, and the production of CO is reduced. In addition, as a characteristic of the admixture of parallel flow, the exhaust gas in the furnace is entangled in the air from the outside of the guide groove and is recirculated before mixing with the fuel flow. Flow, mixing with the fuel flow is delayed,
Combustion becomes slower, the bond between N ₂ and O ₂ slows down, and N
Generation of O _X is also reduced. Further, since the flow velocity is high, the flame extends to the inside of the furnace, and the heating in the furnace is made uniform.
In the industrial furnace of the above (4) and the heat storage combustion burner of the above (18), since the air nozzle separator is provided on the air supply / exhaust surface of the burner tile between the ventilation holes, the air is ejected from the air supply holes. Combustion air is prevented from flowing to the exhaust holes,
All of the combustion air can contribute to combustion. In the industrial furnace of (5) above and the burner for heat storage combustion of (19) above, since the vent holes are narrowed toward the air supply / exhaust surface, the flow rate of air supply is further increased. Further, since the center of the vent hole is brought closer to the axial center of the protrusion, the fuel entrainment is further enhanced. In the industrial furnace of the above (6) and the burner for heat storage combustion of the above (20), the fuel injection nozzle is rotated in accordance with the rotation of the rotating disk, so that the pilot flame can always be directed to the air supply hole side. , Ignition is stabilized. Above (7)
In the industrial furnace of (1) and the burner for heat storage and combustion of (21) above, since the sub-combustion tube is provided, it is possible to suppress the diffusion of combustion air even at low temperature, stabilize combustion, and reduce both CO and NOx. . In the industrial furnace of (8) and the burner for heat storage and combustion of (22), since the auxiliary combustion cylinder is provided and the tip portion thereof is narrowed, the dispersion of combustion air can be further suppressed, combustion is stabilized, and CO , NOx are also reduced. Further, since the exhaust gas return hole is provided, the exhaust gas can be introduced into the auxiliary combustion cylinder, and NOx
Is further reduced. The industrial furnace of the above (9), the above (2
In the heat storage combustion burner of 3), since the auxiliary combustion cylinder is provided,
Even when the temperature is low, the combustion air can be prevented from being scattered, the combustion is stable, and both CO and NOx are reduced. (7),
The length of the auxiliary combustion cylinder may be shorter than that in (21). In the industrial furnace of (10) and the burner for heat storage and combustion of (24), since the space is provided between the inner surface of the ventilation hole and the inner surface of the protrusion, the pressure in the area A can be made lower than the surroundings. It is possible to suppress the dispersion of the air supply immediately after leaving the air vent by pushing the air supply immediately after exiting the air vent toward the area A. In the industrial furnace of the above (11) and the burner for heat storage and combustion of the above (25), the first portion of the ventilation hole is inclined obliquely inward, and the wall surface of the second portion on the side close to the burner tile axis is set to the first wall. Since it is inclined to the side opposite to the inclination of part 1, the charge air is directed in the direction of the fuel flow at low temperature, the mixture of fuel and charge air is strengthened, and the charge air becomes almost parallel to the flow fuel flow at high temperature. As a result, NOx reduction can be achieved. In the industrial furnace of the above (12) and the heat storage combustion burner of the above (26), in the burner of the ventilation hole, an inclined flat surface is provided on a portion of the inner surface of the ventilation hole far from the burner tile axis. Immediately after exiting the ventilation hole, the supply air flows in a direction in which it obliquely collides with the fuel flow and the mixing of the fuel and the supply air is strengthened, and at high temperatures, the distribution of the supply air increases due to the action of the above-mentioned oblique plane, resulting in low NOx It comes off. In the industrial furnace of the above (13) and the burner for heat storage combustion of the above (27), the auxiliary vent hole for supplying a part of the air supply is provided between the vent hole and the fuel discharge port. The connection between the area and the main flame area is improved and combustion is stabilized. Further, when the temperature is high, the flow rate of the supply air increases, the static pressure at the upstream end of the auxiliary air vent decreases, and the amount of air supplied through the auxiliary air supply hole decreases, so that the increase in NOx can be prevented. The above (14) exemplifies various kinds of industrial furnaces to which the present invention can be applied.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 6 and 21,
FIG. 22 shows the combustion method of the industrial furnace, the burner for heat storage combustion, and the industrial furnace of the first embodiment of the present invention, and FIGS.
Shows an industrial furnace and a heat storage combustion burner of a second embodiment of the present invention, FIG. 9 shows an industrial furnace and a heat storage combustion burner of a third embodiment of the present invention, and FIG. 10 shows a fourth embodiment of the present invention. 11 shows an industrial furnace and a heat storage and combustion burner of an embodiment, FIG. 11 shows an industrial furnace and a heat storage and combustion burner of a fifth embodiment of the present invention, and FIGS. 12 and 13 show a sixth embodiment of the present invention. FIG. 14 shows an industrial furnace and a burner for heat storage combustion, and FIG.
1 shows an industrial furnace and a burner for heat storage combustion of an embodiment, and FIG.
5 to 17 show an industrial furnace and a heat storage combustion burner of an eighth embodiment of the present invention, and FIGS. 18 to 20 show an industrial furnace and a heat storage combustion burner of a ninth embodiment of the present invention. 23
Indicates a comparative example (conventional example). Common components have the same reference numerals throughout the embodiments of the present invention.

The present invention can be applied to both the industrial furnace 100 and the regenerative combustion burner 1. When the present invention is applied to an industrial furnace, for example, a heat storage combustion burner has a structure that can be separated into a plurality of parts, and a part of them (for example, a burner tile or a burner tile and a frame body described later). , Etc.) are fixed to the furnace body of the industrial furnace to form a member on the furnace body side or a part of the furnace body. Further, the industrial furnace 100 includes a melting furnace, a sintering furnace, a preheating furnace, a soaking furnace, a forging furnace, a heating furnace, an annealing furnace, a tempering furnace, a plating furnace,
Drying furnace, tempering furnace, quenching furnace, tempering furnace, redox furnace,
Baking furnace, baking furnace, roasting furnace, melting and holding furnace, former furnace, crucible furnace, homogenizing furnace, aging furnace, reaction furnace, distillation furnace, ladle drying preheating furnace, mold firing preheating furnace, normalizing furnace, raw It includes an attaching furnace, a carburizing furnace, a coating drying furnace, a holding furnace, a nitriding furnace, a salt bath furnace, a glass melting furnace, a boiler including a power generation boiler, an incinerator including a refuse incinerator, a hot water supply device, and the like.

First, the structure common to all the embodiments of the present invention will be described.
For example, description will be made with reference to FIGS. 1 to 6 and FIGS. 21 and 22. As shown in FIGS. 1, 2 and 21, the industrial furnace 100 and the heat storage combustion burner 1 according to the embodiment of the present invention.
Is a burner tile 22 through which the fuel injection nozzle 20 is inserted.
A heat storage body 30 that surrounds the fuel injection nozzle 20 and is divided into a plurality of parts by, for example, partition walls 31, and a partition wall 41 that is arranged at one end of the heat storage body 30 in the axial direction to supply and exhaust air. It comprises an air supply ventilation opening 42 and a switching mechanism 40 having an exhaust air ventilation opening 43 on the other side. The industrial furnace 100 and the heat storage combustion burner 1 may further have a frame body 10 in which the fuel injection nozzle 20, the heat storage body 30, and the switching mechanism 40 are assembled. Industrial furnace 1
In the case of 00, the burner tile 22, or the burner tile 22 and the frame body 10 may be fixed to the furnace wall 5 side to form a member on the furnace 100 side.

Industrial furnace 100 and heat storage combustion burner 1
Is a ventilation means (for example, a blower,
A compressor or the like) 4 and is opened to the atmosphere via the exhaust passage 3. On the other hand, the fuel injection nozzle 20
Fuel from and primary air (also called pilot air)
Then, the supply air flowing from the supply air ventilation opening 42 through the heat storage body 30 is fed into the furnace 100. Switching mechanism 4
0 switches the flow of the supply air and the exhaust gas to the divided portion of the heat storage body at predetermined time intervals (for example, every 20 seconds to several minutes). The supply air, which was at about 20 ° C. on the upstream side of the heat storage body 30, is warmed when passing through the heat storage body 30, and is heated at about 900 when it flows from the air injection nozzle (vent) 26 into combustion air. When the temperature of the exhaust gas reaches the heat storage body 30, the temperature of the heat storage body rises to, for example, about 1000 ° C. When the heat storage body 30 passes through the heat storage body 30, the temperature of the heat storage body is raised to about 200 ° C. Then, the switching mechanism 40
Switches the air supply / exhaust, passes the air supply to the place where the exhaust gas had been flowing until then, and passes the exhaust gas to the place where the air supply had been flowing until then. Thus, the heat of the exhaust gas is stored in the heat storage body 30, and the supply air is warmed by the heat stored when the supply air is switched.

FIG. 2 is an enlarged view showing an example of a part of the industrial furnace 100 and the burner 1 for heat storage combustion. The fuel injection nozzle 20 extends in the axial direction at the center of the burner, and a primary air (pilot air) pipe 21 extends concentrically with the burner. The outer peripheral surface of the fuel injection nozzle 20 and the primary air (pilot air) pipe 21 are connected to each other. Primary air (pilot air) flows through an annular passage between the inner peripheral surface and the inner peripheral surface. An insulator for electrical insulation is provided on the outer peripheral surface of the fuel injection nozzle 20 except for the tip portion, and a portion (about 10%) of the fuel is piloted to the side portion at the tip portion where the insulator is not provided. A pilot fuel discharge port for discharging as fuel is provided, and the pilot fuel injected from there is electrically sparked between the tip end portion of the fuel injection nozzle 20 where the insulator is not provided and the primary air pipe 21. It is designed to ignite when it is skipped.

3 and 4 show the detailed structure of the burner tile 22. The burner tile 22 has an air supply / exhaust surface 23 having a plurality of ventilation holes 26 for switching between air supply and exhaust.
And the protruding portion 2 protruding from the air supply / exhaust surface 23 toward the inside of the furnace.
4 and a fuel opening surface 25 formed from the inside of the protrusion 24 to the tip to open the fuel / primary air mixture. The protrusion distance of the protrusion 24 from the air supply / exhaust surface 23 is 1/3 or more, preferably 1/2 or more, of the diameter of any one vent hole 26 in order to obtain the effect of the protrusion 24 described later. Has been done. The vent hole 26 functions as an air supply hole at one time and as an exhaust hole at another time, and supply / discharge is switched. Switching between supply and discharge is performed by a switching mechanism 40 described later. On the air supply / exhaust surface 23 of the burner tile 22, an air nozzle separator 29 is provided so as to protrude between the ventilation holes 26,
Combustion air ejected from the air supply holes is prevented from flowing to the exhaust holes, and all the combustion air can contribute to combustion. The fuel release surface 25 is formed so as to widen toward the tip of the protrusion 24. The divergent structure may be tapered, R (curved), the tapered surface or the R surface may be a smooth surface, and may be jagged (contact area is It may be a surface (to make it large).

A guide groove 27 extending in the axial direction may be formed on the outer peripheral side of the protrusion 24 so as to be concentric with the vent hole 26 (however, the guide groove 27 is not essential). When the guide groove 27 is provided, the ventilation hole 2
In the air supply (secondary air, main air) outflowing through the air vents 26, which function as air supply holes, at least a part of the air supply passes through the guide grooves 27 and has a strong directivity and a high flow velocity 28A. Becomes The vent hole 26 is smoothly narrowed as it approaches the air supply / exhaust surface 23 in the air supply flow direction (however, the opening end of the vent hole 26 to the air supply / exhaust surface 23 is the vent hole 2 of the exhaust gas).
6 may be used as the R portion 26R for smoothing the inflow into the chamber 6.) When the supply air that has passed through the heat storage body 30 passes through the ventilation hole 26, the flow velocity is increased. Further, the vent hole 26 has a passage center closer to the axial center side of the protrusion 24 as it approaches the air supply / exhaust surface 23 in the air supply flow direction. Vent hole 26
It is desirable that at least a part of the cross section of the vent hole 26 on the air supply / exhaust surface 23 overlaps with the projecting portion 24, and a guide groove 27 is formed on the side surface of the projecting portion of this overlapping portion.
Therefore, the vent hole 26 is not blocked by the protrusion 24. However, the ventilation hole 26 may be arranged so that the cross section of the ventilation hole 26 on the air supply / exhaust surface 23 is in contact with the outer periphery of the protruding portion 24. In that case, it is not necessary to provide a guide groove on the side surface of the protruding portion 24. .

The heat storage body 30 is made of a heat-resistant material such as honeycomb-shaped ceramic or heat-resistant metal, and preferably has a monolith honeycomb structure in order to increase the contact area with gas. However, the structure in which the contact area with the gas is large is not limited to the honeycomb structure, and may be, for example, a structure in which wire rods or pipes having a small diameter are bundled. The heat storage body 30 allows gas to pass in the axial direction. The heat storage body 30 is composed of a plurality of heat storage body portions that are separated from each other in the circumferential direction by the partition wall 31 or by being built in a sleeve independent of each other. The heat storage body 30 may be divided into a plurality of heat storage body portions in the axial direction in order to prevent the occurrence of cracks due to a temperature gradient and facilitate manufacturing. When the heat storage body 30 is divided into a plurality of heat storage body portions in the axial direction, a spacer 32 made of a heat-resistant material is interposed between the heat storage body portions at the time of assembly so that a small amount (for example, about 3 A turbulent flow may be generated by forming a gap 33 of 5 mm).
By providing a turbulent flow field, from the exhaust gas to the heat storage body 30,
In addition, heat transfer from the heat storage body 30 to the supply air is improved.

5 and 6 show details of the switching mechanism 40 side. The heat storage body 30 and the partition wall 31 are stationary members, and at least a part of the switching mechanism 40 is a movable member. For example, in the example of FIG. 5, the partition wall 41 and the disk 44 are movable members. Further, in the example of FIG. 7, the rotary disk 44 is a movable member, and the fixed disk 46 that is in sliding contact with the rotary disk 44 and has the hole 47 is a stationary member. A movable member of the switching mechanism 40 is rotationally driven by a driving unit (for example, a motor, a cylinder, etc.) 45. The heat storage body 30 is separated into a plurality of parts by a partition wall 31, for example. The partition wall 31 extends radially as shown in FIG. 6, and divides the heat storage body 30 into a plurality of (2 or more, 4 in the embodiment of FIG. 6) circumferentially. On the other hand, the partition wall 41 of the switching mechanism 40 extends in the circumferential direction, and forms the air supply passage 2 on one of the inner peripheral surfaces and the exhaust passage 3 on the other. Of the disc 44, an air supply ventilation opening 42 is formed in one of the inner and outer circumferences of the partition wall 41, and an exhaust air ventilation opening 43 is formed in the other. The air supply ventilation opening 42 is provided on the air supply passage 2 side, and the exhaust air ventilation opening 43 is provided on the exhaust passage 3 side.
Provided on the side. The disk 44 is a spring 51 and a partition wall 41.
Is pressed against the end surface of the (see FIG. 11). When the disk 44 is rotated and the air supply / exhaust ventilation openings 42, 43 pass through the partition wall 31 of the heat storage body 30, the flow of supply / exhaust of the divided portion of the heat storage body 30 is switched.

In the heat storage portion divided into a plurality of parts, the volume of the portion covered by the exhaust ventilation opening 43 is equal to or larger than the volume of the portion covered by the supply ventilation opening 42. The number and shape of the openings 42, 43 for use are set. For example, the heat storage body 30 is divided into four by the partition wall 31.
When divided into three pieces, three or two are covered by the exhaust ventilation opening 43, and one or two are covered by the supply ventilation opening 42. By increasing the exhaust volume, the exhaust pressure loss is reduced, and therefore the total pressure loss is also reduced and the blower capacity can be reduced. Further, since the exhaust gas flow velocity is also reduced, the heat storage body 30 can easily store heat, and the heat recovery rate is improved. Further, when the driving means 45 is composed of a motor, it is installed closer to the air supply passage 2 than the partition wall 41 in order to prevent the motor from being affected by the heat of the exhaust gas. In addition, in the heat storage part separated into a plurality, the ventilation holes 26 of the burner tile 22 are provided on the downstream side of each of the heat storage parts.
Is provided. Of the ventilation holes 26, the sum of the passage sectional areas of the ventilation holes 26 covered by the exhaust ventilation opening 43 is equal to or more than the sum of the passage sectional areas of the ventilation holes 26 covered by the air supply ventilation opening 42. As described above, the numbers and shapes of the supply and exhaust ventilation openings 42 and 43 are set. For example,
In the example of FIGS. 4 to 6, the number of ventilation holes covered by the exhaust ventilation opening 43 is three or two, and the supply ventilation opening 42 is 42.
There are one or two vent holes covered by.

Next, the combustion method of the industrial furnace and the burner for heat storage combustion, which is implemented by the above-described common structure, will be described. In the combustion method of the industrial furnace and the burner for heat storage combustion of the embodiment of the present invention, the air is supplied from the vent hole which is formed in the air supply / exhaust surface 23 and which is switched between the supply and discharge, and which functions as the air supply hole. Is supplied to the furnace, and the supply air is the supply / exhaust surface 2
3, the furnace exhaust gas is entrained in the flow of supply air while flowing to the tip of the projection 24 along the side surface of the projection 24 protruding forward, and a part of the furnace exhaust gas is circulated in the furnace to supply air. And a part of the in-furnace exhaust gas entrained in the supply air mixes with the flow of fuel released from the fuel release surface 25 formed inside the protrusion 24 when the flow reaches the tip of the protrusion 24. The fuel is burned while forming a fuel region that extends in the depth direction of the furnace 5 by flowing it forward of the protrusion 24. Further, the combustion method of the industrial furnace and the burner for heat storage combustion of the embodiment of the present invention is such that the exhaust gas burned in the furnace is ventilated through the vent holes 26 which serve as exhaust holes among the plural vent holes 26 which can be switched between supply and discharge. In the discharging step, a short circuit from the fuel opening surface 25 to the vent hole 26 of the fuel released into the furnace is caused in the discharging step. It is suppressed by being separated by the length.

Next, the operation of the above common structure will be described with reference to FIGS.
This will be described with reference to FIGS. 6 and 21 to 23. Since the projecting portion 24 is projected from the air supply / exhaust surface 23 and the fuel open surface 25 is formed inside the projecting portion 24, the fuel open surface 25 and the vent hole of the vent hole 26 which functions as an exhaust hole are separated,
The flow 28B of the mixture of the fuel and the primary air that has exited from the fuel opening surface 25 is less likely to be entrained in the exhaust flow 28C that flows through the exhaust holes. The exhaust flow 28C gathers from the surroundings toward the exhaust hole near the exhaust hole, and the exhaust flow is not strong at the tip of the protruding portion. When the fuel is entrained in the exhaust gas, the fuel hardly burns and flows from the fuel open surface 25 to the exhaust hole by short-circuiting. Further, the amount of oxygen in the exhaust gas is small, so the fuel is incompletely burned and a large amount of CO is generated. However, in the embodiment of the present invention, since the entrainment of fuel into the exhaust gas is suppressed, CO is significantly reduced. FIG. 22 shows 100,000 Kcal / h combustion test results of the industrial furnace and the burner for heat storage combustion of the present invention. As shown in FIG. 22, CO emission is extremely small.

Further, the fuel release surface 25 is separated from the air supply / exhaust surface 23, and the sum of the cross-sectional areas of the vent holes which function as the air supply holes among the air holes 26 indicates the disconnection of the air holes which function as the exhaust holes. Due to the fact that the supply air velocity is high because it is less than the sum of the areas, when the supply air flows along the side surface of the protrusion 24, the exhaust gas in the furnace is entrained in the supply air and strongly circulated (see FIG. 21). ), Combustion becomes slow. As a result, the NOx generation amount is reduced to about 20 ppm as shown in FIG. An industrial furnace 5'provided with a conventional heat storage combustion burner 1 '(Fig. 2
In 3), about 200 ppm NOx is produced, and in a normal burner furnace, about 2000 ppm NOx is produced.
Compared with them, the amount of NOx produced is greatly reduced.

Further, as the combustion becomes slower, the combustion region R extends toward the back of the furnace as compared with the combustion region R'of the conventional furnace, and the temperature T of the combustion region is averaged as shown in FIG. Turn into. That is, the temperature difference ΔT is the temperature difference Δ of the conventional furnace.
It is smaller than T ′ (FIG. 23). Therefore, under the condition that the maximum temperature is equal to or lower than the furnace wall allowable temperature Ta, the temperature T in the combustion region R can be raised as a whole as compared with the conventional temperature T '. As a result, the average heat flux can be increased over almost the entire combustion region R, highly efficient heat transfer is possible, and when the same heat transfer is achieved, the furnace body is made compact,
Space efficiency can be improved and initial cost can be reduced. Further, by averaging the combustion region temperature T, it is possible to avoid locally raising the temperature of the furnace wall, thereby extending the life of the furnace and reducing the maintenance cost. Further, the combustion noise is reduced due to the slow combustion.

Further, since the fuel opening surface 25 is formed in a divergent shape toward the tip of the protruding portion, while the fuel and the primary air are flowing inside the fuel opening surface 25, the exhaust flow 28
Even if the fuel is attracted from C to the exhaust hole side, the fuel release surface 25 becomes an obstacle and the entrainment in the exhaust flow 28C is suppressed. Further, since the fuel release surface 25 has a flared shape, the fuel is more likely to accompany the supply air flow 28A, and is easily mixed with the supply air to be completely combusted. By this, C
Less O is produced. Projection 24 and fuel release surface 25
Due to the structure that spreads toward the end, about 30
CO, which was 00 ppm, is reduced to about 200 ppm or less.

Further, since the guide groove 27 is formed on the side portion of the projecting portion 24, the supply air flowing out from the ventilation hole 26 is
At least a part thereof enters the guide groove 27. The supply air that has entered the guide groove 27 flows linearly in the guide groove 27 and flows out from the tip of the protruding portion forward with directivity. This flow is a flow with a large flow velocity, because the flow velocity does not remain constant because there is almost no diffusion while flowing through the guide groove 27. The force of this flow to attract and accompany the fuel is great. This associated force further suppresses the inclusion of fuel in the exhaust gas, and reduces the above-mentioned CO of about 200 ppm or less to about 100 pp.
m or less. Even if the fuel is mixed with the charge air having a large directivity and a large flow velocity, the mixing of the fuel and the charge air is not instantaneously promoted, and the flow of the charge air is gradually mixed as the flow of the charge air moves downstream. It burns slowly and in the process burns completely. Further, since the flow of the guide groove 27 entrains the exhaust gas from the outside, the combustion becomes slow due to lack of oxygen. This slow combustion also slows the bond between N ₂ and O ₂ ,
Generation of O _X is also greatly reduced. Furthermore, due to the high flow velocity and slow combustion, the flame further extends deep inside the furnace and the inside of the furnace is heated over the whole area, which enables more uniform heating and the heating of the inside of the furnace. You will be able to heat things sufficiently.

Further, since the ventilation hole 26 is narrowed as it approaches the air supply / exhaust surface 23, the flow velocity of the supply air is increased when the supply air passes through the ventilation hole 26. As a result, the action due to the high supply air flow velocity is further strengthened. Further, since the center of the vent hole 26 is located closer to the axis of the protruding portion, when the air supply exits the vent hole 26, a considerable part of the air enters the guide groove 27. Then, the above-mentioned directional air supply flow is generated more strongly. Further, in order to further improve the reactivity, the axis of the vent hole 26 may be slightly inward (10 to 20 degrees) inward (the direction in which the air supply approaches the axis of the protrusion).

Next, the construction and action peculiar to each embodiment of the industrial furnace and the burner for heat storage combustion of the present invention will be explained. In the first embodiment of the present invention, the burner tile 22 is a stationary member and is fixed to the frame body 10 or the furnace body 5.
Therefore, the vent hole 26 is formed by the disc 44 of the switching mechanism 40.
When the same vent hole 26 is provided, it functions as an air supply hole, and when it is the same, it functions as an exhaust hole according to the switching of supply and discharge by rotation of.
Other configurations and actions are as described in the common configuration and actions.

In the second embodiment of the present invention, as shown in FIGS. 7 and 8, the primary air pipe 21 and the fuel injection nozzle 20 are integrally rotatably connected to each other by an electric insulating material 20b. Then, the primary air pipe 21 is connected to the rotary disc 44.
The fuel injection nozzle 20 also rotates in synchronization with the rotation of the disk 44. Further, the pilot fuel discharge port 20a is directed toward the vent hole 26 which functions as an air supply hole. By rotating the fuel injection nozzle 20 in synchronism with the disk 44, the direction of the air supply hole in the air hole 26, which functions as an air supply hole, and the direction of the pilot fuel discharge port 20a always match, and combustion air is constantly supplied to the ignition flame. Combustion at ignition is stable.

In the third embodiment of the present invention, as shown in FIG. 9, the air supply / exhaust surface 23 surrounds a plurality of ventilation holes 26 from the outer peripheral side and is coaxial with the projection 24 in the axial direction. A sub-combustion cylinder 60 having a right cylindrical shape is provided extending from the tip to the front position. The auxiliary combustion cylinder 60 is made of metal and has a frame 10
Fixed to. The combustion gas goes out from the tip of the auxiliary combustion cylinder 60, and the exhaust gas enters from the tip of the auxiliary combustion cylinder 60. When the temperature of the combustion air is low, the velocity of the air in the air supply hole is slow, so the combustion air easily disperses (diffuses) when it exits the air supply hole. However, by providing the auxiliary combustion cylinder 60, the air scattering is suppressed. Therefore, air shortage is unlikely to occur, and combustion is stable. As a result, CO can be further reduced to about 10 ppm or less. Moreover, NOx becomes about 30 ppm or less.

In the fourth embodiment of the present invention, as shown in FIG. 10, the air supply / exhaust surface 23 surrounds a plurality of ventilation holes 26 from the outer peripheral side and is coaxial with the projection 24 in the axial direction. A cylindrical sub-combustion cylinder 61 having a narrowed tip is provided extending from the tip to the front position. The auxiliary combustion cylinder 61 is made of metal and is fixed to the frame body 10. The combustion gas flows out from the tip of the auxiliary combustion cylinder 61, and the exhaust gas enters from the rear end of the auxiliary combustion cylinder 61. Exhaust gas return holes 62 corresponding to the guide grooves 27 are provided at the rear end of the auxiliary combustion cylinder 61 in the same number as the guide grooves 27. By providing the auxiliary combustion cylinder 61, it is possible to suppress air scattering. Since the tip of the auxiliary combustion cylinder 61 is narrowed, it is possible to further suppress the spread of air as compared with the third embodiment. As a result, air shortage is less likely to occur,
Combustion is stabilized and CO is further reduced (10 ppm or less). The amount of exhaust gas that enters the auxiliary combustion cylinder 61 from the end of the auxiliary combustion cylinder 61 is small because the tip of the auxiliary combustion cylinder 61 is narrowed, but since the exhaust gas also enters the auxiliary combustion cylinder 61 through the exhaust gas return hole 62, there is a pressure loss. Does not increase. Exhaust gas return hole 6 at high temperature
Since the amount of exhaust gas entering the sub-combustion cylinder 61 from 2 also increases, combustion becomes slower and NOx does not increase.

In the fifth embodiment of the present invention, as shown in FIG. 11, the projection 24 having the guide groove 27 is surrounded from the outer peripheral side and is coaxial with the projection 24 in the axial direction from the tip of the projection 24. A cylindrical auxiliary combustion cylinder 63 extending to the front position is provided integrally with the protrusion 24. The auxiliary combustion cylinder 63 is shorter than the auxiliary combustion cylinder 60 of the third embodiment. The sub combustion cylinder 63 is made of the same material (ceramics) as the burner tile 22. The rear end of the auxiliary combustion cylinder 63 is separated from the air supply / exhaust surface 23 by the thickness of the air nozzle separator 29. Secondary combustion cylinder 63
As described above, the dispersion (spreading) of the combustion air is suppressed as in the third embodiment. As a result, air shortage is less likely to occur, combustion is stabilized, and CO is further reduced (10 p
pm or less). Further, the rear end of the auxiliary combustion cylinder 63 and the air supply / exhaust surface 23
The space between and functions similarly to the exhaust gas return hole 62 of the fourth embodiment.

In the sixth embodiment of the present invention, FIGS.
As shown in FIG. 4, a space A is provided in the burner tile radial direction between the inner surface of the downstream end of the vent hole 26 of the burner tile 22 and the outer surface of the protrusion 24. An air nozzle separator 29 extends radially outward from the outer surface of the protrusion 24. The air nozzle separator 29 separates the flow of the air supply and the flow of the exhaust air that pass through each vent hole 26. By providing the gap A, it is difficult for the air supplied from the vent hole 26 to be scattered in the direction away from the side surface of the protruding portion 26. This is because the air in the gap A is entrained in the air supply and the air is not freely supplied to the region of the distance A from the surroundings, so that the protrusion 24 and the air nozzle separator 29 side (in the space around the air supply flow) ( It is considered that this is because the pressure in the (A region) becomes relatively lower than that on the opposite side, and the air supply flow is pushed toward the A region in a direction substantially perpendicular to the air supply flow. By suppressing the dispersion of the supply air, it becomes unnecessary to provide the auxiliary combustion cylinders 61 and 63. Further, the suppression of air supply dispersion allows the flame to extend further deep into the furnace.

In the seventh embodiment of the present invention, as shown in FIG. 14, the vent hole 26 of the burner tile 22 has a first portion 26D and a first portion 26 which are located on the downstream side in the supply air flow direction.
D has a second portion 26U extending from the upstream side. The first portion 26D protrudes by a first angle θ _D (θ _D is 2 to 10 degrees) so that the extension on the downstream side of the axis thereof approaches the axis of the protrusion 24 (approaches the fuel flow). It is inclined from the direction parallel to the axis of the portion 24. Also, the second part 2
Of the inner surface of 6U, the wall surface on the side closer to the burner tile axis is inclined by a second angle θ _U (where θ _U > θ _D ) to the opposite side of the inclination of θ _D of the first portion 26D. . Due to the inclination of the first portion 26D, the supply air is inclined in the direction in which it collides with the fuel flow, and the dispersion of the supply air is suppressed.
It is not necessary to provide 1 and 63. Further, when the temperature is low, the supply air immediately after exiting the vent hole 26 has its flow direction directed obliquely inward by the first portion 26D and collides with the fuel flow. As a result, the mixing of fuel and charge air is strengthened, and flame and combustion are stabilized. When the temperature is high, the amount of heat supplied from the heat storage body to the supply air becomes large, the supply air temperature rises, the supply air volume increases, and the supply air flow velocity increases, so that the supply air flow in the second portion 26U is moved to the outside. The directing action is strengthened, and the first portion 26D
The effect of directing the air supply flow inward is canceled out. As a result, the supply airflow as a whole becomes substantially parallel to the fuel flow, the mixing of the fuel and the supply air is suppressed, and NOx generation is suppressed.

In the eighth embodiment of the present invention, FIGS.
As shown in FIG. 5, the vent hole 26 of the burner tile 22 is formed of a nozzle having a shape in which a cylinder is cut along an oblique plane 26F. The diagonal flat surface 26F is formed on a portion of the inner surface of the vent hole 26, which is far from the burner tile axis. The direction of inclination of the oblique plane 26F is such that the downstream extension of the oblique plane 26F approaches the extension of the axial center of the protrusion 24. Since the oblique flat surface 26F is provided, the flow direction of the supply air immediately after exiting the vent hole 26 is directed obliquely inward and the dispersion of the supply air is suppressed. Therefore, the auxiliary combustion cylinders 61 and 63 are not provided. I'm done. Also, at low temperatures, the supply air flows in a plane 2 direction.
Since the air is directed diagonally inward by the 6F, the charge air exiting the vent hole 26 collides with the fuel flow, the mixture of the fuel and the charge air is strengthened, and the flame and combustion are stabilized. When the temperature is high, the amount of heat supplied to the supply air from the heat storage body becomes large, the supply air temperature rises and the supply air flow velocity increases, and as shown in FIG. Burning is possible and NOx reduction is achieved.

In the ninth embodiment of the present invention, FIGS.
As shown in FIG. 7, the burner tile 22 is provided with a sub-ventilation hole 26S between the vent hole 26 and the fuel discharge port for supplying a part of the supply air to the front of the tip surface of the protrusion 24. The number of the sub vent holes 26S is arbitrary. The upstream end of the sub-vent hole 26S is opened to the inner surface of the vent hole 26, and the downstream end of the sub-vent hole 26S is opened to the tip surface of the protrusion 24. A tangent line of a portion of the inner surface of the vent hole 26 on the upstream side of the upstream opening end of the sub-ventilation hole 26S protrudes inward of the ventilation hole 26 from a portion on the downstream side of the upstream opening end of the sub-ventilation hole 26S. Although a portion between the vent hole 26 and the fuel discharge port is an air-deficient region, by guiding a part of the air supply through the sub-vent hole 26S, the flame is stabilized. As shown in FIG. 20, a pilot flame region P exists near the tip of the fuel nozzle, and a secondary flame (main flame) region M exists in the mixed region of the main fuel and the supply air from the vent hole 26. The sub-ventilation hole 26 is provided in a region between the pilot flame region P and the secondary flame (main flame) region M.
By supplying a part of the supply air through S, the flame connection is improved and the flame is stabilized. When the temperature is low, the flow velocity of the supply air is low, so the static pressure at the upstream end of the sub-ventilation hole 26S becomes high, and a part of the supply air flows through the sub-ventilation hole 26S, so that the stabilization of the flame is obtained. When the temperature is high, the amount of heat supplied to the supply air from the heat storage body is large, the supply air flow velocity is increased, and the supply air flow velocity is increased, so that the static pressure at the upstream opening end of the sub air vent 26S is reduced, and the sub air vent 26S. The flow of supply air through the exhaust gas is reduced, and NOx increase can be prevented.

[0032]

According to the industrial furnace of claim 1, the burner for heat storage combustion of claim 15, and the method of burning the industrial furnace of claims 28 and 29, the protrusion is provided and the tip of the fuel release surface is supplied. Since the exhaust surface is separated from the exhaust surface in the axial direction, the entrainment of fuel into the exhaust flow and the short-circuit flow to the exhaust hole are suppressed, and the production of CO can be significantly suppressed. Further, when the temperature is high, due to the axial projection distance, the exhaust gas in the furnace is entrained in the air, and then the slow combustion occurs in which the fuel is encountered, so that the generation of NOx can be suppressed. Furthermore, the slow combustion allows the combustion zone to be extended further into the furnace and the combustion zone temperature to be averaged.
As a result, the temperature in the combustion region can be raised overall, the average heat flux can be increased, and high-efficiency heat transfer can be achieved, making the furnace body compact, improving space efficiency, and initial cost for the same heat transfer. Can be reduced. Further, by averaging the combustion region temperature, it is possible to avoid locally raising the temperature of the furnace wall, thereby extending the life of the furnace body and reducing the maintenance cost. Further, the combustion noise is reduced due to the slow combustion. According to the industrial furnace of claim 2 and the heat storage and combustion burner of claim 16, since the fuel release surface has a flared shape, it is possible to enhance the concomitant property of fuel supply to the exhaust air. Can be further suppressed. According to the industrial furnace of claim 3 and the heat storage and combustion burner of claim 17, since the guide groove is provided on the outer peripheral side of the protrusion,
It is possible to increase the directivity and flow velocity of the charge air, enhance the entrainment of the fuel to the charge air, and further suppress the generation of CO, and, in combination with the effect of entraining the exhaust gas from the outside of the guide groove, slow combustion, generation of NO _X can be reduced.
The flame can also be extended to the back of the furnace. According to the industrial furnace of claim 4 and the burner for heat storage and combustion of claim 18, since the air nozzle separator is provided on the air supply / exhaust surface of the burner tile between the ventilation holes, the combustion ejected from the air supply holes. Air can be prevented from flowing to the exhaust holes, and all of the combustion air can be contributed to combustion. According to the industrial furnace of claim 5 and the burner for heat storage and combustion of claim 19, since the vent holes are narrowed, the flow rate of the supply air can be increased, and the effect obtained by the large supply air flow rate can be further enhanced. it can.
According to the industrial furnace of Claim 6 and the burner for heat storage combustion of Claim 20, since the fuel injection nozzle can be rotated in accordance with the rotation of the disk, the pilot fuel discharge direction and the position of the air supply hole can always be aligned. It is possible to stabilize combustion at the time of ignition. According to the industrial furnace of claim 7 and the heat storage and combustion burner of claim 21, since the sub-combustion tube is provided, it is possible to suppress the dispersion of combustion air at low temperature, prevent air shortage, and further reduce CO. it can. According to the industrial furnace of claim 8 and the heat storage and combustion burner of claim 22, since the auxiliary combustion cylinder is provided and the tip thereof is squeezed, it is possible to suppress the dispersion of combustion air at low temperature and to prevent air shortage. , CO can be further reduced. According to the industrial furnace of claim 9 and the burner for heat storage and combustion of claim 23, since the sub-combustion cylinder is provided in the protruding portion, it is possible to suppress the dispersion of combustion air at low temperatures and to prevent air shortage, and to reduce C
O can be further reduced. In the industrial furnace of (10) and the burner for heat storage and combustion of (24), since the space is provided between the inner surface of the ventilation hole and the inner surface of the protrusion, the pressure in the area A can be made lower than the surroundings. It is possible to suppress the dispersion of the air supply immediately after leaving the air vent by pushing the air supply immediately after exiting the air vent toward the area A. According to the industrial furnace of claim 11 and the burner for heat storage and combustion of claim 25, the first portion of the ventilation hole is inclined obliquely inward, and the wall surface of the second portion close to the burner tile axis is formed into the first wall portion. Since it is inclined to the side opposite to the inclination of part 1, the charge air is directed in the direction of the fuel flow at low temperature, the mixture of fuel and charge air is strengthened, and the charge air becomes almost parallel to the flow fuel flow at high temperature. As a result, NOx reduction can be achieved. In the industrial furnace according to claim 12 and the burner for heat storage combustion according to claim 26, in the burner of the vent hole, an oblique flat surface is provided in a portion of the inner surface of the vent hole far from the burner tile axis, so that the vent hole is provided at a low temperature. Immediately after leaving the air, the charge air flows in the direction in which it obliquely collides with the fuel flow, and the mixing of fuel and charge air is strengthened,
At high temperatures, the action of the above-mentioned oblique plane increases the dispersion of the supply air to achieve low NOx. In the industrial furnace according to claim 13 and the burner for heat storage combustion according to claim 27, since the auxiliary vent hole for supplying a part of the supply air is provided between the vent hole and the fuel discharge port, when the temperature is low, the auxiliary flame region and the pilot flame region are provided. The connection with the main flame area is improved and combustion is stabilized. Further, when the temperature is high, the flow rate of the supply air increases, the static pressure at the upstream end of the auxiliary air vent decreases, and the amount of air supplied through the auxiliary air supply hole decreases, so that the increase in NOx can be prevented. The present invention can be applied to various kinds of industrial furnaces exemplified in claim 14.

[Brief description of drawings]

FIG. 1 is an overall schematic sectional view of an industrial furnace and a burner for heat storage combustion of the present invention.

FIG. 2 is an enlarged cross-sectional view of a part of the industrial furnace and the burner for heat storage combustion in FIG.

FIG. 3 is a cross-sectional view of the burner tile portion in FIG. 2 according to the first embodiment of the present invention.

FIG. 4 is a plan view of FIG. 3;

5 is a cross-sectional view of a portion corresponding to the switching mechanism and its vicinity in FIG. 2. FIG.

FIG. 6 is a plan view of FIG.

FIG. 7 is an enlarged cross-sectional view of a part of an industrial furnace according to a second embodiment of the present invention and a switching mechanism of a burner for heat storage combustion and the vicinity thereof.

FIG. 8 is an enlarged cross-sectional view of the burner tile and its vicinity in FIG. 7 according to the second embodiment of the present invention.

FIG. 9 is an enlarged cross-sectional view of a part of an industrial furnace and a burner tile for heat storage and combustion according to a third embodiment of the present invention and its vicinity.

FIG. 10 is an enlarged cross-sectional view of a part of an industrial furnace according to a fourth embodiment of the present invention and a burner tile of a burner for heat storage combustion and the vicinity thereof.

FIG. 11 is an enlarged cross-sectional view of a part of an industrial furnace according to a fifth embodiment of the present invention and a burner tile of a burner for heat storage combustion and the vicinity thereof.

FIG. 12 is an enlarged cross-sectional view of a part of an industrial furnace according to a sixth embodiment of the present invention and a burner tile of a burner for heat storage combustion and the vicinity thereof.

FIG. 13 is a plan view of FIG.

FIG. 14 is an enlarged cross-sectional view of a part of an industrial furnace according to a seventh embodiment of the present invention and a burner tile of a burner for heat storage combustion and the vicinity thereof.

FIG. 15 is an enlarged cross-sectional view of a part of an industrial furnace according to an eighth embodiment of the present invention and a burner tile of a burner for heat storage combustion and the vicinity thereof.

16 is a plan view of FIG.

FIG. 17 is a perspective view of a vent hole in FIG. 15.

FIG. 18 is an enlarged cross-sectional view of a part of an industrial furnace according to a ninth embodiment of the present invention and a burner tile of a burner for heat storage combustion and the vicinity thereof.

FIG. 19 is a plan view of FIG. 18.

FIG. 20 is a diagram showing a positional relationship between the pilot flame and the main flame in FIG. 18.

FIG. 21 is a schematic view of an industrial furnace of the present invention and heat flux distribution in the furnace.

22 is a diagram showing the relationship between CO and NOx production amounts and furnace temperature in the industrial furnace of FIG. 21.

FIG. 23 is a schematic view of an industrial furnace having a conventional heat storage and combustion burner and heat flux distribution in the furnace.

[Explanation of symbols]

 1 Burner for Heat Storage Combustion 2 Air Supply Passage 3 Exhaust Passage 4 Blower Means 5 Furnace Body 10 Frame 20 Fuel Injection Nozzle 21 Primary Air Pipe 22 Burner Tile 23 Supply / Exhaust Surface 24 Projection 25 Fuel Opening Surface 26 Vent 26D First Part 26F Plane 26S Sub-ventilation hole 26U Second part 27 Guide groove 30 Heat storage body 31 Partition wall 40 Switching mechanism 42 Air supply ventilation opening 43 Exhaust ventilation opening 44 Disc 60, 61, 63 Secondary combustion cylinder 100 Industrial furnace

Continuation of the front page (72) Inventor Ryoichi Tanaka 2-53, Shirate, Tsurumi-ku, Yokohama-shi, Kanagawa Japan Furnace Industry Co., Ltd.

Claims (29)

[Claims] 1. A supply / exhaust surface having a plurality of vent holes for switching supply / discharge, a protrusion protruding from the supply / exhaust surface, and an injection fuel formed from the inside to the tip of the protrusion to release the injected fuel. An industrial furnace having a burner tile having a fuel release surface, the burner tile being fixed to a furnace body. 2. The industrial furnace according to claim 1, wherein the fuel opening surface is formed so as to spread toward the tip of the protruding portion. 3. A guide groove, which is concentric with the vent hole and extends in the axial direction, is formed on an outer peripheral side portion of the projecting portion.
Industrial furnace described. 4. The industrial furnace according to claim 1, wherein an air nozzle separator is formed on the air supply / exhaust surface in a portion between the ventilation holes, the air nozzle separator protruding in a protruding direction of the protruding portion. 5. The industrial furnace according to claim 1, wherein the vent hole is narrowed as it approaches the air supply / exhaust surface, and the vent hole center is made closer to the axial core side of the protrusion as it approaches the air supply / exhaust surface. 6. The vent hole and the fuel release surface are formed in a burner tile, and a primary (pilot) air supply pipe is communicated with the fuel release surface and a fuel injection nozzle is disposed therein to supply and discharge the fuel. The industrial furnace according to claim 1, wherein a switching mechanism is provided for switching the rotary disk, and the fuel injection nozzle is rotatable according to the rotation of the rotary disk. 7. A straight combustion sub-combustion cylinder that surrounds the plurality of ventilation holes from the outer peripheral side and extends axially concentrically with the projection from the tip of the projection to the front position. Industrial furnace described. 8. A cylindrical sub-combustion tube having a narrowed front end, which surrounds the plurality of vent holes from the outer peripheral side and extends axially concentrically with the projection from the front end of the projection. The industrial furnace according to claim 1, further comprising an exhaust gas return hole provided at a rear end portion of the auxiliary combustion cylinder. 9. An air nozzle separator is formed on the air supply / exhaust surface between the ventilation holes, the air nozzle separator projecting in a projecting direction of the projecting portion, and the projecting portion having the guide groove is surrounded from the outer peripheral side and The industrial furnace according to claim 3, further comprising a tubular auxiliary combustion cylinder that extends axially from the front end of the air nozzle separator to the front position of the protrusion in the axial direction concentrically with the protrusion. 10. The industrial furnace according to claim 1, wherein an inner surface of the downstream end of the vent hole and an outer surface of the protrusion are separated from each other in the burner tile radial direction. 11. The vent has a first portion located on the downstream side in the supply air flow direction and a second portion connected to the first portion from the upstream side in the supply air flow direction, The first portion is inclined at a first angle in a direction in which its axis extends toward the downstream and approaches the extension of the protrusion axis, and the inner surface of the second portion closer to the burner tile axis. Is the first
The industrial furnace according to claim 1, wherein the industrial furnace is tilted in a direction opposite to a tilt direction of the first portion at a second angle larger than the angle. 12. The ventilation hole has a shape obtained by cutting a cylindrical nozzle with a plane extending obliquely, and the plane is formed in a portion of an inner surface of the ventilation hole far from a burner tile axis. The industrial furnace according to claim 1, wherein the industrial furnace is inclined in a direction toward the extension of the protrusion axis toward the downstream direction. 13. The burner tile is provided with a sub-ventilation hole which is opened at a tip end surface of the projecting portion and can supply a part of the air supply passing through the vent hole to the front side of the tip end surface of the projecting portion. The industrial furnace according to claim 1, which is provided. 14. The industrial furnace is a melting furnace, a sintering furnace, a preheating furnace, a soaking furnace, a forging furnace, a heating furnace, an annealing furnace, a tempering furnace, a plating furnace, a drying furnace, a tempering furnace, a hardening furnace. , Tempering furnace, redox furnace, firing furnace, baking furnace, roasting furnace, melting and holding furnace, front furnace,
Crucible furnace, homogenizing furnace, aging furnace, reaction furnace, distillation furnace, ladle drying preheating furnace, mold preheating furnace, leveling furnace, brazing furnace, carburizing furnace, coating drying furnace, holding furnace, nitriding furnace, salt The industrial furnace according to claim 1, which is one of a bath furnace, a glass melting furnace, a boiler including a power generation boiler, an incinerator including a refuse incinerator, and a water heater. 15. A supply / exhaust surface having a plurality of vent holes for switching supply / discharge, a projection protruding from the supply / exhaust surface, and an injection fuel formed from the inside to the tip of the projection is released. A burner for heat storage combustion having a fuel open surface. 16. The burner for heat storage combustion according to claim 15, wherein the fuel release surface is formed to widen toward the tip of the protruding portion. 17. The burner for heat storage combustion according to claim 15, wherein a guide groove that is concentric with the vent hole and extends in the axial direction is formed on an outer peripheral side portion of the protruding portion. 18. The heat storage combustion burner according to claim 15, wherein an air nozzle separator is formed on the air supply / exhaust surface at a portion between the ventilation holes so as to project in a projecting direction of the projecting portion. 19. The heat storage combustion burner according to claim 15, wherein the vent hole is narrowed as it approaches the air supply / exhaust surface, and the vent hole center is made closer to the axial center of the protrusion as it approaches the air supply / exhaust surface. 20. The vent hole and the fuel release surface are formed in a burner tile, a primary pilot) air supply pipe is connected to the fuel release surface, and a fuel injection nozzle is arranged inside the pipe to switch between supply and discharge. 16. The burner for heat storage combustion according to claim 15, wherein a switching mechanism of a rotary disk switching type is provided, and the fuel injection nozzle is rotatable in accordance with the rotation of the rotary disk. 21. A sub-cylinder auxiliary combustion cylinder that surrounds the plurality of ventilation holes from the outer peripheral side and extends axially concentrically with the projection from the tip of the projection to the front position. Burner for heat storage combustion described. 22. A cylindrical sub-combustion tube having a narrowed front end, which surrounds the plurality of vent holes from the outer peripheral side and extends axially concentrically with the projection to a position forward of the front end of the projection. The burner for heat storage combustion according to claim 15, further comprising an exhaust gas return hole provided at a rear end portion of the auxiliary combustion cylinder. 23. An air nozzle separator is formed on the air supply / exhaust surface between the ventilation holes so as to project in the projecting direction of the projecting portion, and the projecting portion having the guide groove is surrounded from the outer peripheral side and The burner for heat storage combustion according to claim 17, further comprising a tubular auxiliary combustion cylinder that extends axially from the front end of the air nozzle separator in a concentric manner with the protrusion to a position forward of the tip of the protrusion. 24. The burner for heat storage combustion according to claim 15, wherein an inner surface of the downstream end portion of the ventilation hole and an outer surface of the protruding portion are separated from each other in the radial direction of the burner tile. 25. The vent has a first portion located downstream in a supply air flow direction and a second portion connected to the first portion from an upstream side in the supply air flow direction, The first portion is inclined at a first angle in a direction in which its axis extends toward the downstream and approaches the extension of the protrusion axis, and the inner surface of the second portion closer to the burner tile axis. Is the first
16. The burner for heat storage combustion according to claim 15, wherein the burner is tilted in a direction opposite to the tilt direction of the first portion at a second angle larger than the angle. 26. The ventilation hole has a shape obtained by cutting a cylindrical nozzle with a plane extending obliquely, and the plane is formed in a portion of the inner surface of the ventilation hole far from the burner tile axis. The burner for heat storage combustion according to claim 15, wherein the burner for heat storage combustion is inclined in a direction approaching the extension of the projection axis toward the downstream direction. 27. The burner tile is provided with a sub-ventilation hole which is opened at a tip end surface of the projecting portion and can supply a part of air supplied through the vent hole to a front side of the tip end surface of the projecting portion. The burner for heat storage combustion according to claim 15, which is provided. 28. The supply air is supplied into the furnace through a ventilation hole functioning as a supply hole among a plurality of ventilation holes formed on the supply / exhaust surface for switching supply / discharge, and the supply air is the supply / exhaust surface. From the inside of the furnace into the flow of the supply air while flowing to the tip of the projection along the side surface of the projection protruding forward from And a part of the in-furnace exhaust gas entrained in the air supply mixes with the flow of fuel released from the fuel release surface formed inside the protrusion when the flow reaches the tip of the protrusion. And burning the fuel while forming a combustion region extending in the depth direction of the furnace by flowing the fuel toward the front of the protruding portion. 29. The method further comprises the step of discharging the exhaust gas burned in the furnace to the outside of the furnace through a vent hole which functions as an exhaust hole among the plurality of vent holes which can be switched between supply and discharge. 29. The industry according to claim 28, wherein a short circuit of the fuel released from the fuel open surface into the furnace to the vent hole is suppressed by the tip of the fuel open surface being separated from the air supply / exhaust surface by the length of the protrusion. Burning method of furnace.