JP3608697B2 - Regenerative fluidized bed furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a regenerative fluidized bed furnace in which a part of air heated by a regenerative burner is used as fluidizing air and the remaining air is used as combustion air for the regenerative burner. It is.
[0002]
[Prior art]
Conventionally, in the fluidized bed combustor 1 as shown in FIG. 2, it is necessary to heat the fluidized bed 2 formed of dredged sand or the like to the operating temperature. The need to warm up arises. Currently, the general heating methods include the following four types or combinations thereof.
(1) A method of heating with a burner 3 installed at the top of the fluidized bed 2.
(2) A method in which auxiliary fuel such as oil or pulverized coal is supplied from the auxiliary fuel supply nozzle 4 and burned and heated in the sand whose temperature has been raised to some extent.
(3) A method in which gas fuel or the like is injected into the sand and heated by a burner 5 with a pilot flame protection mechanism, which is called a sand burner as shown in FIG.
(4) A method in which the fluidized air heating burner 6 is installed and the combustion gas is mixed with the fluidized air to increase the temperature, thereby heating the fluidized bed.
[0003]
[Problems to be solved by the invention]
However, in either case, since fuel is supplied into the furnace for combustion or combustion gas is supplied into the furnace, the oxygen partial pressure in the furnace decreases, while the water vapor and carbon dioxide partial pressures increase. This causes the following problems depending on each application.
(1) When used as a fluidized bed incinerator, the amount of incineration decreases due to a shortage of oxygen supply.
(2) When used as a fluidized bed heat treatment or reactor, water vapor or the like may affect the object to be heated.
(3) When the fluidized bed temperature is low, unburned substances such as CO and hydrocarbons are generated due to cooling or incomplete combustion of the flame, which is dangerous.
(4) The temperature of the fluidized bed cannot be made lower than the ignition temperature of the auxiliary fuel, and the operation temperature is limited.
The present invention has been made to remedy such problems, and a part of the air heated by the regenerative burner is used as fluidized air, and the remaining air is used for combustion of the regenerative burner. An object of the present invention is to provide a regenerative fluidized bed furnace that is used as air.
[0004]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention comprises a fluidized bed in which a fluidized material is charged into a furnace body, and a pair or a plurality of pairs of regenerative burners are installed to perform switching combustion every predetermined time. It was set as the structure which operate | moves, and it was made to supply a part of air preheated through the thermal storage body of the said regenerative burner to the said fluidized bed as fluidization air.
The present invention also provides a fluidized bed by charging a fluid substance into the furnace body, and providing first and second regenerative burners, and these first and second regenerative burners are provided in the furnace body. It is configured to be connected to the bottom side while communicating with each other on the top side, and the passage near the top side of the first and second regenerative burners is formed to be narrow, and fuel is supplied to the narrowly formed passage. The fuel supply passages are formed so as to be fed in, and the first and second fuel valves are interposed in the fuel supply passages, respectively, the heat storage members are interposed in the first and second regenerative burners, and the bottom portion An air supply means for supplying air and an exhaust means for discharging combustion gas are provided on the side, and the air supply means is formed so as to reach the first and second regenerative burners from the blower and the blower. The air supply path includes first and second air supply valves for opening and closing the flow path, and the exhaust means includes an exhaust path on the bottom side of the first and second regenerative burners, The first and second exhaust flow rate control valves, the first and second exhaust valves are interposed, and the exhaust passage is merged to forcibly exhaust the air. The alternating combustion is performed by alternately opening and closing the supply valve, the first and second fuel valves in the fuel supply passage, and the first and second exhaust valves in the exhaust means at predetermined time intervals. When the latent burner is alternately burned, the air passes through each heat storage body and is preheated by the heat storage body to form high-temperature air, and when passing through the communication passage on the top side of the first and second regenerative burners, Part of the air also into the fluidized bed in the furnace Rashi and was configured to act as a fluidizing air.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Next, a regenerative fluidized bed furnace according to the present invention will be described below with reference to the accompanying drawings with one embodiment.
FIG. 1 shows a regenerative fluidized bed furnace 10, which includes first and second regenerative burners 11 and 12 and fluidizes a part of preheated air. It is configured to be used as air, and a fluidized bed 14 is formed by charging a fluid substance into a furnace body 13 made of a known refractory material, and the first and second regenerative burners 11 and 12 are used. Is provided on the lower side of the fluidized bed 14 to perform the combustion operation alternately.
[0006]
The fluidized bed 14 is composed of dredged sand or the like, and is inserted so as to be held on the bottom side of the furnace body 13. In other words, the fluidized bed 14 is held attached to the bottom side of the furnace body 13, and the air diffused by the diffuser plate 15 spreads over the fluidized bed 14 evenly.
[0007]
The first and second regenerative burners 11 and 12 are connected to the furnace body 13 below the diffuser plate 15 in the fluidized bed 14 and communicate with each other on the top side. Further, the vicinity of the top portions of the first and second regenerative burners 11 and 12 has a small inner diameter, and the first and second fuel supply paths Lf to the first and second fuel supply paths Lf are formed at locations where the inner diameters are reduced. The second fuel valves 16 and 17 are opened and closed to send fuel, and a flame is formed and combustion is performed.
On the other hand, in the drawing of the first and second regenerative burners 11 and 12, heat accumulators 18 and 19 are interposed near the lower ends, respectively. The heat storage bodies 18 and 19 can be configured by filling ceramic balls, for example. Also, other materials can be applied as long as they are breathable and fireproof.
[0008]
Further, on the bottom side of the first and second regenerative burners 11 and 12, an air supply means 20 for supplying air to the first and second regenerative burners 11 and 12, and a combustion gas are forcibly discharged. Exhaust means 21 is provided for this purpose.
The air supply means 20 is for opening and closing the flow path in a blower 22 and an air supply path L1 formed from the blower 22 to the bottom side of the first and second regenerative burners 11 and 12, respectively. First and second air supply valves 23 and 24 are provided.
On the other hand, the exhaust means 21 forms an exhaust path L2 on the bottom side of the first and second regenerative burners 11 and 12, and interposes the first and second exhaust flow control valves 25 and 26, respectively. The exhaust passage L2 is joined through the first and second exhaust valves 27 and 28, and the combustion gas is forcibly discharged by an exhaust fan (not shown).
In other words, the first and second regenerative burners 11 and 12 having such a configuration include the first and second air supply valves 22 and 23 in the air supply means 20 and the first and second fuel valves 16 and 17 in the fuel supply path Lf. Then, the first and second exhaust valves 27 and 28 in the exhaust means 21 are alternately opened and closed every predetermined time to perform alternating combustion. In addition, by adjusting the first and second exhaust flow control valves 25 and 26, the air preheated by the heat storage bodies 18 and 19 of the first and second regenerative burners 11 and 12 flows as fluidized air. The amount supplied to the floor 14 is controlled. The temperature of the fluidized air is determined by the fuel supply amount introduced into the first and second regenerative burners 11 and 12 through the fuel supply passage Lf and the air amount introduced through the air supply passage L1. And so on.
[0009]
In such a configuration, for example, in order to burn the first regenerative burner 11, in the air supply means 20, the first air supply valve 23 is closed, while the second air supply valve 24 is opened, and the second regenerative burner 11 is opened. Air is introduced from the burner 12 side, the second fuel valve 17 in the fuel supply path Lf is closed, the first fuel valve 16 is opened, the first exhaust valve 27 in the exhaust means 21 is opened, and the second exhaust valve 28 is opened. And the combustion gas is discharged from the first regenerative burner 11 through the exhaust passage L2. Here, the waste heat is recovered by the combustion gas passing through the heat storage body 18 in the first regenerative burner 11.
On the other hand, in order to burn the second regenerative burner 12, the first air supply valve 23 in the air supply means 20 is opened, air is introduced from the first regenerative burner 11 side, and the second regenerative burner 12 in the fuel supply path Lf. The fuel valve 17 is opened (see FIG. 1), the second exhaust valve 28 in the exhaust means 21 is opened, the first exhaust valve 27 is closed, and the combustion gas is discharged from the second regenerative burner 12 through the exhaust path L2. To do.
[0010]
As described above, when the first and second regenerative burners 11 and 12 are alternately burned, the air passes through the heat accumulators 18 and 19 and is preheated by the waste heat stored in the heat accumulators 18 and 19 to become a high temperature. The air passes through the communication passages of the first and second regenerative burners 11 and 12 facing the diffuser plate 15 at the bottom of the furnace body 13, and a part of the air passes through the diffuser plate 15 at that time. It is brought to the fluid bed 14 on the side and is configured to act as fluidized air.
[0011]
In the regenerative fluidized bed furnace 10 configured as described above, a series of operations are performed as follows.
In order to burn the first regenerative burner 11, in the air supply means 20, the first air supply valve 23 is closed, while the second air supply valve 24 is opened and air is supplied from the second regenerative burner 12 side. Is introduced. The air passes through the heat storage body 19 in the second regenerative burner 12, is heated to high temperature by the waste heat stored in the heat storage body 19, and faces the diffuser plate 15 at the bottom of the furnace body 13. Passing through the communication passages of the active burners 11 and 12, a part of the hot air is brought to the fluidized bed 14 on the furnace body 13 side through the diffuser plate 15 and acts as fluidized air (FIG. 1). The remaining air is introduced into the first regenerative burner 11 as combustion air.
Then, the first fuel valve 16 in the fuel supply path Lf on the first regenerative burner 11 side is opened, and a flame is formed and burnt at a location where the inner diameter near the top of the first regenerative burner 11 is set small. . The flow rate of the combustion gas is adjusted by the opening degree of the first exhaust flow rate control valve 25 in the exhaust means 21, and the first exhaust valve 27 is opened, so that the combustion gas passes through the heat storage body 18 in the first regenerative burner 11. As the combustion gas passes, waste heat is recovered by the heat storage body 18 and is discharged through the exhaust passage L2.
[0012]
On the other hand, in order to burn the second regenerative burner 12, the first air supply valve 23 in the air supply means 20 is opened and air is introduced from the first regenerative burner 11 side via the heat storage body 18, High-temperature combustion air is brought to a location where the inner diameter in the vicinity of the top of the second regenerative burner 12 is set small, and the second fuel valve 17 in the fuel supply passage Lf is opened and burned. A part of the heated air at this time is also brought to the fluidized bed 14 on the furnace body 13 side through the diffuser plate 15 and can act as fluidized air.
Then, the flow rate is adjusted by the opening degree of the second exhaust flow control valve 26 in the exhaust means 21, the second exhaust valve 28 is opened, and the combustion gas is allowed to pass through the heat storage element 19 on the second regenerative burner 12 side. Thus, waste heat can be recovered and discharged through the exhaust path L2.
[0013]
As described above, in the above-described regenerative fluidized bed furnace 10, air heated by the heat accumulators 18 and 19 stored in advance using the first and second regenerative burners 11 and 12 as fluidized air. Since it is possible to supply the fluidized bed 14, the oxygen concentration of the fluidized air does not decrease. Therefore, when employed as an incinerator, it is possible to suppress a decrease in the amount of incineration.
Further, since the combustion gas is discharged from the lower side of the first and second regenerative burners 11 and 12 through the heat storage bodies 18 and 19 by the exhaust means 21, the combustion gas is discharged into the fluidized bed 14. In the case where the regenerative fluidized bed furnace 10 is applied as a heat treatment furnace or a reaction apparatus, the influence of water vapor or carbon dioxide on the object to be heated can be minimized.
The temperature of the fluidized bed is controlled by adjusting the temperature of fluidized air by adjusting the amount of fuel supplied from the fuel supply passage Lf and the amount of combustion air introduced through the air supply passage L1. Thus, it is possible to arbitrarily control the temperature in a wide temperature range from high to high, and there is no problem that the flame is cooled by the low temperature fluidized bed, which is a disadvantage of the prior art, and unburned substances are generated.
[0014]
【The invention's effect】
As described above, in the present invention, a part of the air heated by the regenerative burner is used as fluidizing air, and the remaining air is used as combustion air for the regenerative burner. Like combustion equipment, combustion exhaust is not mixed in the furnace due to fluidized bed heating, oxygen partial pressure in the furnace atmosphere is reduced, and steam and carbon dioxide partial pressure is increased. Absent. Thereby, (1) When applied to an incinerator, a decrease in incineration amount can be suppressed.
(2) The influence of water vapor or carbon dioxide on the object to be heated can be minimized.
(3) Generation of unburned material can be prevented.
(4) Operation is possible over a wide temperature range.
[0015]
[Brief description of the drawings]
FIG. 1 is a schematic system explanatory diagram showing an example of a regenerative fluidized bed furnace in the present invention.
FIG. 2 is a schematic system explanatory diagram showing an example of a current fluidized bed furnace.
3 is a schematic configuration explanatory view showing an example of a burner for injecting and heating into the fluidized bed in the fluidized bed furnace shown in FIG. 2; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Regenerative fluidized bed furnace 11 1st regenerative burner 12 2nd regenerative burner 13 Furnace body 14 Fluidized bed 15 Diffuser plate 16 1st fuel valve 17 2nd fuel valve 18, 19 Thermal storage body 20 Air supply means 21 Exhaust means 22 Blower 23 First supply valve 24 Second supply valve 25 First exhaust flow control valve 26 Second exhaust flow control valve 27 First exhaust valve 28 Second exhaust valve

Claims (2)

A fluidized bed is formed by charging a fluidized material into the furnace body, and a pair or multiple pairs of regenerative burners are installed to perform a combustion operation by switching every predetermined time. The heat storage of the regenerative burner A regenerative fluidized bed furnace characterized in that a part of the air preheated through the body is supplied as fluidized air to the fluidized bed. The fluidized material is charged into the furnace body to form a fluidized bed, and first and second regenerative burners are provided, and the first and second regenerative burners are coupled to the bottom of the furnace body. On the other hand, the first side and the second regenerative burner are configured to communicate with each other on the top side, and the passage near the top side of the first and second regenerative burners is formed to be narrow, and fuel is supplied so that fuel is fed into the narrowly formed passage. The first and second fuel valves are interposed in the fuel supply passages, the heat regenerators are interposed in the first and second regenerative burners, respectively, and air is supplied to the bottom side. An air supply means for supplying and an exhaust means for discharging combustion gas are provided, and the air supply means is provided in a blower and an air supply passage formed from the blower to the first and second regenerative burners. Flow First and second air supply valves for opening and closing the first and second exhaust valves, wherein the exhaust means is provided with an exhaust passage on the bottom side of the first and second regenerative burners, respectively. The flow control valve, the first and second exhaust valves are interposed, and the exhaust passage is merged to forcibly exhaust, and the first and second air supply valves in the air supply means, the fuel supply passage The first and second fuel valves and the first and second exhaust valves in the exhaust means are alternately opened and closed every predetermined time so that alternating combustion is performed, and the first and second regenerative burners are alternately burned. When the air passes through the heat storage body and is preheated by the heat storage body to form high-temperature air, when passing through the communication passages on the top side of the first and second regenerative burners, a part of the air is passed through the furnace body. Bring to the fluidized bed of fluid Regenerative Restorative fluidized bed furnace, characterized by being configured to act as an air.

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