JPH0311201A - Structure of combustion chamber of boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention is a boiler that burns recycled solid fuel. Regarding the structure of the combustion chamber.

2. Description of the Related Art A conventional boiler in which a moving grate is provided at the bottom of a combustion chamber and uses solid fuel is shown in FIG. 2, for example. A moving bed grate 1 is disposed between a front wall 3 and a rear wall 4 of a combustion chamber 2, and a wind box 5 for supplying combustion air is provided below the moving bed grate 1. A fuel supply hopper 6 is disposed above the starting end entrance of the moving bed grate 1, and a fuel supply hopper 6 is disposed below the front wall 3, extending to the front of the lower end of the lower wall of the 1lfJ wall 3.
An ignition arch portion 7 is provided that covers the. Further, a rear wall arch portion 8 extending rearward from the lower end of the rear wall 4 and extending across the ladder grate 1 is provided below the barrel 4 on the terminal end side of the moving bed grate 1. A large number of water pipes 10A connected to the brackish water drum 12,
70B, and a plurality of screen water pipes 10G are also provided at the combustion chamber outlet 11 formed at the upper end of the rear wall 4.

Problems to be Solved by the Invention Recycled solid fuel (hereinafter referred to as RDF) is mainly composed of wood, has a large amount of volatile components and M parts, has very little attached moisture, has extremely high ignitability, and has a long lifespan when ignited. It emits flame and burns. It is compression-molded and solidified under even greater pressure.

Therefore, when such RDF is supplied to the combustion chamber 2 through the ladder grate 1, when it enters the combustion chamber 2, it simultaneously emits a long flame and burns, and the flame spreads from the ignition arch section 7 along the surface of #wall 3. and extends upward. Therefore, before! S! 3 water pipe 10A
The amount of absorbed heat becomes abnormally high, and incineration ash becomes difficult to adhere to.

In addition, at the end of the movable grate 1, the unburned content in the fuel is reduced by the rear wall arch part 8, but the length of the rear wall arch part 8 completely burns the RDF compression molded under high pressure. The atmosphere could not be maintained, and there was a risk that unburned matter would remain in the incinerated ash, resulting in a lingering odor.

Furthermore, in order to sufficiently combust RDF in the combustion chamber 2, it is effective to supply secondary air; is rising. Due to the radiant heat of this high-temperature combustion, the incinerated ash melts at the end of the ladder grate 1, causing trouble.
In addition, the ash adhering to the screen water pipe 1 (Ic) at the combustion chamber outlet 10 melted and turned into talin, causing trouble.

An object of the present invention is to solve the above-mentioned problems and provide a combustion chamber structure for a boiler that can prevent extreme heating and troubles even when recycled solid fuel with high ignitability and long flame is used. .

Means for Solving the Problems In order to solve the above-mentioned problems, a first light cutter is provided in a combustion chamber of a boiler having a ladder grate at the bottom for burning recycled solid fuel. At the lower end of the straight front wall at the end of the fire arch disposed above the entrance, a protrusion projecting from the front wall surface toward the combustion chamber is provided over at least the entire width of the ladder grate.

In addition, the second 11-day test is carried out in the combustion chamber of the boiler, which has a ladder grate at the bottom that burns recycled solid fuel.
1' A rear wall arch part that projects toward the combustion chamber from near the straight lower part of the rear wall is installed above the rear part of the moving grate. The depth is set in the range of 1/3 to 1/2 of the depth length to the shaped part, and the tip of the rear wall arch part is inclined upwardly at the rear part through the curved part and continues to the straight part of the rear wall. It is connected to the wall slope.

In addition, the third invention is such that, in a combustion chamber of a boiler having a ladder grate for burning recycled solid fuel at the bottom, a screen pipe disposed at the combustion exhaust gas outlet at the upper part of the wall is moved downward toward the combustion chamber side. It is tilted.

Operation In the configuration of the first aspect of the invention, the recycled solid fuel charged into the inlet of the ladder grate is ignited as soon as it enters the combustion chamber, emits a long flame, and starts combustion. This long flame is guided into the combustion chamber along the ignition arch and tries to rise from the end of the ignition arch along the straight front wall, but is once separated from the wall by the protrusion and guided into the combustion chamber. In order to be
The flame is prevented from rising along the l1fJ wall surface, and problems such as local heating of the water pipe and melting of attached ash can be prevented.

Further, in the configuration of the second invention, the furnace depth length is 173
The long arch section of the rear wall, which reaches ~1/2, maintains the atmosphere at the end of the ladder grate well, allowing complete combustion to the center even if the recycled solid fuel is compression molded at high pressure. It is possible to make combustion ash odorless. Also,
The combustion gas guided to the tip of the rear wall arch is drawn from the curved part to the straight part of the rear wall via the sloped part of the rear wall, making the combustion chamber narrowed by the arch part of the rear wall more effective. Can be used for Furthermore, this rear wall arch 8 blocks high-temperature radiant heat radiated from the center of the combustion chamber to the end of the ladder grate, thereby preventing the incineration ash on the ladder grate from melting and clinker. This prevents troubles caused by ash melting.

Furthermore, in the configuration of the third invention, high-temperature radiant heat and combustion exhaust gas are concentrated in the screen water pipe of the combustion chamber exit [1], but the screen wood pipe is tilted so that the surface thereof is directed upward away from the center of the combustion chamber. As a result, the angle at which the radiant heat from the center of the combustion chamber is received is tilted to a greater extent than in the past, and the amount of radiant heat received can be significantly reduced, thereby preventing problems with melting of attached ash.

EXAMPLE An example of the present invention will be described below with reference to FIG. The same members as those in the prior art are given the same reference numerals, and their explanations will be omitted.

A protrusion 21 that protrudes toward the combustion chamber 2 side is formed over the entire width at the lower end of the front wall 3 in order to separate the flame blowing out along the ignition arch 7 from the surface of the front wall 3. This protrusion 21 continuously protrudes from the ignition arch part 7, detours through an arcuate surface, and connects to the front wall 3, and the protrusion from the front wall 3 is set to 100 to 200 pieces. This guides the flame from the ignition arch into the combustion chamber 2m, and #! I!
It can prevent it from rising along the surface of 3.

The rear wall 22 has a middle portion formed into a straight portion 22a along a vertical plane. A ladder grate 1 projects from the vicinity of the lower part of this straight portion 22a toward the combustion chamber 2 side by a predetermined length ρ, with a slight upward slope.
A rear wall arch portion 22b is provided to cover the rear wall arch portion 22b. The length ρ of this rear wall arch portion 22b is set to 173 to 1/2 of the depth length L between the front wall 3 and the superior wall straight portion 22a, and the recycled solid fuel A compressed at high pressure is used. I of the ladder grate 1 is the atmospheric temperature that allows complete combustion to the center! It can be held at the end.

Further, the tip of the rear wall arch portion 22b has a curved portion 2 with a radius γ.
A first inclined portion 12 that slopes upwardly at the rear via 2G.
d, and the upper end of the first inclined portion 22d is straight g522
connected to a. The radius γ of the curved portion 22c is 0.23
Q≦γ≦0132!2 is set to be large, and the combustion gas flowing out from the rear wall arch portion 22b into the combustion chamber 2 is pulled back to the rear wall vertical portion 2289f, and the rear wall arch ols22
The combustion chamber 2 is configured to effectively utilize the space inside the combustion chamber 2, which is narrowed by b. In addition, this arch portion 22b blocks radiant heat from the center of the combustion chamber 2, which is burned at a high temperature with secondary air, and prevents the incineration ash at the end portion of the ladder grate 1 from melting and from generating clinker. .

Furthermore, a second inclined part 2 whose upper part is inclined toward the combustion chamber 1 side at an angle α with respect to the vertical plane from the upper end of the rear wall straight part 22b.
2e are arranged in series, and the opening surface of the combustion chamber outlet 23 formed on the second inclined portion 22d is configured such that the lower side thereof is inclined at an angle β toward the combustion chamber 19J. Here, the second slope part 2
The inclination angle α of 2d is set to 20° to 35°, and the inclination angle β of the combustion chamber outlet 23 is set to 13.5° or more. Therefore, the screen water pipe 24 disposed at the combustion chamber outlet 23 is also
By being inclined at an angle of 3.5" or more, and by orienting its surface in a direction significantly different from the center of the combustion chamber 2,
Receiving high-temperature radiant heat from the center of the combustion chamber 2 from a more oblique direction than the conventional vertical surface can greatly reduce the amount of heat received, and prevents the melting of incinerated ash adhering to the screen water pipe 2a and clinker. can be prevented from forming.

Effects of the Invention As described above, according to the first invention, the flame from the ignition arch is guided to the combustion chamber side by the protrusion and is temporarily passed from the 1lfI wooden wall, so that the flame does not travel along the front wall. It is possible to prevent problems such as local heating of the nrI wall water pipe and melting of adhering ash.

Further, according to the second light space, the long rear wall arch portion allows the recycled solid fuel to be completely combusted to the center, making the incinerated ash odorless. In addition, the combustion gas discharged from the rear wall arch into the combustion chamber can be drawn to the rear wall straight part via the curved part and the inclined slope part, so that the rear wall arch can be moved downward from the rear wall straight part. Even if it is made to protrude toward the combustion chamber side, the combustion chamber space can be used effectively. Furthermore, since the rear wall arch protrudes toward the combustion chamber side, it is possible to block the high-temperature radiation heat radiated from the center of the combustion chamber to the end of the ladder grate, melting incinerated ash, and melting the incinerated ash. problems can be prevented.

Furthermore, according to the third invention, since the surface of the screen wood pipe that receives radiant heat is oriented in a direction significantly different from the center of the combustion chamber, the amount of radiant heat received from the center of the combustion chamber can be significantly reduced, and the surface of the screen water pipe This can prevent problems with melting of adhering ash.

[Brief explanation of drawings]

Fig. 1 is a schematic vertical cross-sectional view of the combustion chamber of a boiler showing one embodiment of this Komei, and Fig. 2 is a schematic vertical cross-sectional view of the combustion chamber of a conventional boiler.
11 is a sectional view. 1... Ladder grate, 2... Combustion chamber, 3... Front wall,
7... Ignition arch section, 11... Combustion chamber outlet, 21...
...Protrusion, 22... Posterior instep, 22a... Straight part, 22
b... Shun wall arch part, 22c... Curved part, 22d.
...First slope part, 23... Combustion chamber outlet, 24... Screen water pipe, A... Refuse recycled solid fuel (RDF),
L... Combustion chamber depth length, 2... Return wall arch length.

Claims (1)

[Scope of Claims] 1. In the combustion chamber of a boiler, which is provided with a moving bed grate for burning recycled solid fuel at the bottom, a combustion chamber directly above the terminal end of the ignition arch section disposed above the inlet of the moving bed grate. A combustion chamber structure for a boiler, characterized in that a protrusion projecting from the front wall surface toward the combustion chamber is provided at the lower end of the shaped front wall over at least the entire width of the moving bed grate. 2. In a combustion chamber of a boiler equipped with a moving bed grate for burning recycled solid fuel at the bottom, a rear wall projecting toward the combustion chamber from near the straight lower part of the rear wall above the rear part of the moving bed grate; An arch portion is provided, the protruding length of the rear wall arch portion is set in a range of 1/3 to 1/2 of the depth length from the front wall to the rear wall straight portion, and the tip of the rear wall arch portion is A combustion chamber structure for a boiler, characterized in that the combustion chamber is connected via a curved portion to a rear wall inclined portion that slopes upwardly at the rear and continues to a straight rear wall portion. 3. In the combustion chamber of a boiler equipped with a moving bed grate for burning recycled solid fuel at the bottom, the screen pipe installed at the flue gas outlet at the top of the wall is tilted downward toward the combustion chamber. Characteristic boiler combustion chamber structure.