JPH11201443A - Rdf combustion tubular boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the concentration of dioxin in an exhaust gas. SOLUTION: A connection port 10 between the inside of a combustion room 2 and a tubular group 4 being installed on a combustion room ceiling wall 2a is provided at the side edge part of a combustion room rear wall 2c of the combustion room ceiling wall 2a. The inside of the combustion room 2 is partially screened by a lower partition wall 15 and an upper partition wall 16. The lower partition wall 15 is arranged so that a combustion gas 8 can pass its upper portion, and the upper partition wall 16 is arranged so that the combustion gas 8 can pass its lower part. The combustion gas 8 meanders while being screened by the lower partition wall 15 and the upper partition wall 16 and tends to stay longer in the combustion room 2, thus suppressing the generation of dioxin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an RDF as a fuel.
The present invention relates to a small-sized RDF-burning fire tube boiler that uses a gas turbine.

[0002]

2. Description of the Related Art A conventional small-sized fire tube boiler using a solid fuel has a stoker furnace 1 in which a stoker (movable grate) 3 is arranged at the bottom of a combustion chamber 2 as shown in FIG. The smoke tube group 4 is placed on the combustion chamber ceiling wall 2a, and the solid fuel 6 continuously supplied from the inlet 5 provided in the combustion chamber front wall 2b is supplied to the stoker 3 by
Supplied from the wind box 7 through the hole (slit) 3a
Combustion is performed by secondary air, and the combustion gas generated by the combustion is further combusted by secondary air supplied through a nozzle 9 provided in the combustion chamber 2 to obtain a high-temperature combustion gas 8. Through the communication port 10 opened at the end of the combustion chamber ceiling wall 2a on the side of the combustion chamber front wall 2b.
After passing through the smoke tube group 4 and exchanging heat with boiler water for cooling, the gas is discharged from the exhaust port 11 as a discharge gas 8a.

On the other hand, fine ash generated during combustion of the solid fuel 6 is dropped from the hole 3a of the stalker 3,
The large slag that does not fall is transported by the stoker 3 to the rear wall 2c of the combustion chamber, and is collected and discharged in the pit 12 at the bottom.

However, in the stoker-fired fire tube boiler, when the combustion gas 8 generated in the combustion chamber 2 passes from the combustion chamber 2 to the smoke tube group 4 through the communication port 10, an arrow A shown in FIG.
Therefore, the residence time of the combustion gas 8 in the combustion chamber 2 is relatively short. Therefore, when using RDF containing a chlorine compound derived from dust as a fuel, there is a problem that sufficient measures against dioxin cannot be taken.

[0005] Therefore, in the stoker-fired fire tube boiler, as a measure against dioxin by using RDF,
As shown in FIG. 4, a partition plate 13 is provided so as to extend horizontally from an upper position of the inlet 5 of the front wall 2b of the combustion chamber toward the rear wall 2c of the combustion chamber and partition the inside of the combustion chamber 2 up and down. Has been proposed, in which the fuel gas is once led to the rear wall 2c side of the combustion chamber and then turned back to extend the residence time of the combustion gas 8 in the combustion chamber 2.

[0006]

However, in the case of the type shown in FIG. 4, the partition plate 1 for regulating the flow of the combustion gas 8 is used.
Since the ash accumulates on the upper surface of the stalker 3, there is a problem that continuous operation cannot be performed for a long time, and there is also a problem that clinker is generated on the stalker 3 to hinder ash extraction.

Accordingly, the present invention provides an RDF that can extend the residence time of a combustion gas in a combustion chamber and reduce dioxin concentration in exhaust gas without hindering ash accumulation or ash deposition. It is intended to provide a combustion tube boiler.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention solves the above-mentioned problem by charging RDF from a charging port provided in a front wall of a combustion chamber onto a stalker provided at a bottom portion of the combustion chamber and burning the RDF. A communication port for leading the combustion gas in the combustion chamber to the smoke tube group in the RDF combustion tube boiler, which is configured to discharge the gas through the smoke tube group installed on the combustion chamber ceiling wall, is provided behind the combustion chamber on the combustion chamber ceiling wall. A partition wall is provided at an end on the wall side and a partition wall for meandering the flow of the combustion gas in the vertical direction is attached to a required position on the communication port side in the combustion chamber.

[0009] When the combustion gas generated by the combustion of the RDF on the stalker moves to the communication port in the combustion chamber,
Since it is blocked by the partition walls and meandered in the vertical direction, the residence time in the combustion chamber is prolonged, and the gas temperature is made uniform by the stirring effect. As a result, the generation of dioxin can be suppressed.

Further, the partition is constituted by a lower partition for diverting the flow of the combustion gas from above to below and an upper partition for diverting from below to above, and the lower partition and the upper partition are arranged so as to be separated from each other. Since the flow of the combustion gas can be repeatedly detoured from above to below and from below to above, the residence time of the combustion gas in the combustion chamber can be further extended, and the number of times of stirring can be increased, so that complete combustion is performed. Therefore, the dioxin concentration in the exhaust gas can be reduced.

Further, by employing a configuration in which a plurality of lower partition walls and upper partition walls are alternately arranged, the residence time of the combustion gas in the combustion chamber can be further extended.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of an RDF combustion fire tube boiler according to the present invention. In the structure similar to that of the stoker-fired fire tube boiler shown in FIG. 3, the height of the combustion chamber 2 of the stoker furnace 1 is increased. Thus, the capacity of the combustion chamber 2 is increased, and a communication port 10 between the combustion chamber 2 and the smoke tube group 4 is provided at the end of the combustion chamber ceiling wall 2a on the side of the combustion chamber rear wall 2c. In the combustion chamber 2, a lower partition wall 15 and an upper partition wall 16 as baffles for making the flow of the combustion gas 8 meander in the vertical direction are separated from each other at predetermined positions on the communication port 10 side.
That is, a lower partition 15 having a vertical dimension such that a gas detour is formed between the RDF 14 supplied to the stalker 3 and the combustion chamber ceiling wall 2a at a required position on the downstream side of the nozzle 9 where the RDF 14 is burned out. Is mounted between the left and right side walls of the combustion chamber, and an upper partition wall 16 having an up-down dimension such that a gas detour is formed between the combustion chamber ceiling wall 2a and the stoker 3 at an end position on the side of the communication port 10, Installed between the left and right side walls of the combustion chamber. Note that a gap 17 is formed between the lower end of the lower partition wall 15 and the stalker 3 so that the RDF can pass therethrough. Reference numeral 18 denotes an auxiliary partition.

In FIG. 1, the same parts as those in FIG. 3 are denoted by the same reference numerals.

RD supplied from the inlet 5 into the combustion chamber 2
F14 is burned on the stalker 3 by the primary air and the secondary air as in the case of the solid fuel 6 shown in FIG. The high-temperature combustion gas 8 generated by this combustion flows through the communication port 10 to the smoke pipe group 4. At this time, the combustion gas 8 is first raised by being blocked by the lower partition 15, and is raised. 2, and then, is shielded by the upper partition 16, is detoured by 180 degrees, is lowered, and is guided to the lower part of the combustion chamber 2. Thereafter, the combustion gas 8 hits the rear wall 2c of the combustion chamber, is detoured again by 180 degrees, rises, and is guided to the group of smoke tubes 4 through the communication port 10.

In the above description, the combustion gas 8 is made to meander in the combustion chamber 2 vertically in a large direction.
The residence time in the combustion chamber 2 can be greatly extended, and the time for keeping the combustion gas 8 at a high temperature can be extended. Further, the combustion gas 8 flows above the lower partition 15 and the upper partition 1.
When the gas passes below 6, the gas is stirred by being largely bypassed, so that the gas temperature can be made uniform and the combustion gas 8 can be completely burned. Therefore, the generation of dioxin can be suppressed, and the concentration of dioxin contained in the exhaust gas 8a can be reduced.

Further, since the lower and upper partitions 15 and 16 do not have a wide horizontal plane, there is no danger of ash accumulating on the upper portions. On the other hand, when the RDF 14 is burned, it does not fall out of the hole 3a of the stalker 3 without falling. The slag and the like remaining on the stalker 3 can be transferred to the pit 12 and discharged through the gap 17 between the lower partition wall 15 and the stalker 3 in the same manner as the conventional one.

Next, FIG. 2 shows another embodiment of the RDF combustion tube boiler of the present invention. In the same configuration as the embodiment of FIG. 1, the lower partition wall 15 and the lower partition wall 15 are arranged at alternate positions. The upper partition 16 is provided one by one in the combustion chamber 2. That is, two lower partitions 15 and two upper partitions 16 are arranged in a staggered manner in the gas flow direction.

According to this embodiment, the number of times the combustion gas 8 detours by 180 degrees when moving in the combustion chamber 2 can be increased, and the residence time of the combustion gas 8 in the combustion chamber 2 can be further increased. Since the length can be extended and the number of times of stirring can be increased, the dioxin concentration of the exhaust gas 8a can be further reduced.

The present invention, in the embodiment of FIG.
Although the case where the lower partition wall 15 and the upper partition wall 16 are arranged in the combustion chamber 2 has been shown, it is effective that only one of the partition walls is effective. In the embodiment of FIG.
And the upper partition 16 are provided for two sheets, but a large number such as three sheets and four sheets may be provided, and various changes may be made without departing from the gist of the present invention. Can of course be added.

[0021]

As described above, according to the RDF combustion tube boiler of the present invention, the following excellent effects are exhibited. (1) RDF is injected from a slot provided in the front wall of the combustion chamber onto a stalker provided at the bottom of the combustion chamber to burn it, and the combustion gas is discharged through a group of smoke tubes installed on the ceiling wall of the combustion chamber. A communication port for guiding the combustion gas in the combustion chamber to the group of smoke tubes in the RDF combustion tube boiler is provided at an end of the combustion chamber ceiling wall on the rear side of the combustion chamber, and at a required position on the communication port side in the combustion chamber. In addition, since a partition for making the flow of the combustion gas meander in the vertical direction is attached, the flow of the combustion gas can be made to meander, the residence time in the combustion chamber can be extended, and the combustion gas can be extended. Can be agitated, so that the production of dioxin can be suppressed. (2) The partition wall is a lower partition wall for bypassing the flow of the combustion gas from above to below and an upper partition wall for bypassing from below to above,
Since the lower partition and the upper partition are arranged so as to be separated from each other, the flow of the combustion gas can be repeatedly detoured in the combustion chamber by the upper partition and the lower partition in the vertical direction. The residence time can be made longer, the time for keeping the combustion gas at a high temperature can be prolonged, and the combustion gas can be agitated when it is bypassed by the partition wall to make the gas temperature uniform. Since complete combustion can be performed, generation of dioxin can be effectively suppressed, and therefore, the concentration of dioxin in exhaust gas can be further reduced. (3) With a configuration in which the lower partition and the upper partition are alternately arranged on a plurality of sheets, the residence time of the combustion gas in the combustion chamber can be further increased, so that the dioxin concentration in the exhaust gas is further reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a cut-away side view showing an embodiment of an RDF combustion smoke tube boiler of the present invention.

FIG. 2 is a cut-away side view showing another embodiment of the RDF combustion tube boiler of the present invention.

FIG. 3 is a schematic side view showing an example of a conventional fire tube boiler for solid fuel.

FIG. 4 is a schematic side view showing an example of a proposed RDF combustion smoke tube boiler.

[Explanation of symbols]

 Reference Signs List 2 Combustion chamber 2a Combustion chamber ceiling wall 2b Combustion chamber front wall 2c Combustion chamber rear wall 3 Stalker 4 Smoke tube group 8 Combustion gas 10 Communication port 15 Lower partition 16 Upper partition

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Asai 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. (72) Katsumi Mashiko Inventor Katsumi 3-1-1-15 Toyosu, Koto-ku, Tokyo No.Ishikawajima Harima Heavy Industries, Ltd.

Claims (3)

[Claims] 1. An RDF is charged from a charging port provided in a front wall of a combustion chamber onto a stalker provided in a bottom portion of the combustion chamber and burned, and a combustion gas is discharged through a group of smoke tubes provided on a ceiling wall of the combustion chamber. A communication port for guiding the combustion gas in the combustion chamber to the group of the smoke tubes in the RDF combustion tube boiler thus provided is provided at an end of the combustion chamber ceiling wall on the rear side of the combustion chamber, and the communication port side in the combustion chamber. An RDF combustion tube boiler, wherein a partition for making the flow of combustion gas meander in a vertical direction is attached to a required position. 2. The partition according to claim 1, wherein the partition comprises a lower partition for diverting the flow of the combustion gas from above to below and an upper partition for diverting from below to above, and the lower partition and the upper partition are spaced apart from each other. RDF burning fire tube boiler. 3. The RDF combustion tube boiler according to claim 2, wherein a plurality of lower partition walls and upper partition walls are alternately arranged.