JPH053845Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coal gasification combustor for use in coal-fired boilers with improved slag collection efficiency.

[Conventional technology]

A conventional coal combustor will be explained with reference to FIGS. 4 to 6. FIG. 4 is an explanatory diagram of a conventional inclined coal combustor. In Fig. 4, 1 is a cylindrical inclined slugging combustor, 2 is a primary mixture supply port provided at the end of the slugging combustor and supplies a primary mixture of coal and primary air, and 3 is a slugging combustor. A secondary air supply port is provided on the side wall of the combustor 2 in the tangential direction of a circle centered on the axis of the slugging combustor so as to give a swirling flow to the gas flow; 4 is a slug buff full plate; 5 is a slug This is a slug tap for introducing the slug into the slug bin 6.

Fine coal powder supplied into the slugging combustor 1 from the primary mixture supply port is burned in a swirling flow, and the ash is melted and separated as slug by centrifugal force, which adheres to the inner wall of the slugging combustor 1. After that, it flows down the wall surface and stays in the slug bin 6 via the slug tap 5. Also,
The slag that has not been centrifuged or the slag that has peeled off from the wall surface and is re-splattered collides with and adheres to the slug buffer plate 4. Fig. 5 is an explanatory diagram of a conventional horizontal coal combustor. In Fig. 5, 1 is a cylindrical horizontal slugging combustor, 2 is a primary mixture supply port, and 3 is a secondary air supply port, both of which are slugged. An opening is formed in the side wall of the ging combustor 1 in the tangential direction of a circle centered on the axis.

Note that 4 is a slug buttful plate. Fourth
As shown in FIG. 5, conventional slug separation relies solely on centrifugation. The same applies to vertical combustors.

Figure 6 shows the structure of the slug buffle plate. In FIG. 6, 1 is a slugging combustor, 4 is a slug baffle plate, and 7 is a throat portion. In the case of a horizontal shape as shown by the arrow in the figure, the slag adhering to the wall is likely to peel off and be re-splattered, and the slag that has collided with or adhered to the slug baffle plate is likely to be re-splattered into the gas flow of the throat portion 7.

[Problem that the invention attempts to solve]

The problems with the conventional coal combustor mentioned above are as follows.

(1) Limits of slag separation capacity The conventional type uses centrifugal force to separate slag as shown in Figures 4 to 6, but coal combustors have two methods: coal combustion and combustion ash (sludge) separation. Function must be fulfilled. From the viewpoint of centrifugal separation, the stronger the swirling force is, the more preferable it is, but excessively increasing the swirling force increases the secondary air flow velocity. That is, pressure loss becomes large and power consumption increases. The inner wall of the combustor is worn out. Coal particles collide with the wall surface quickly and are collected in the slag layer, increasing the amount of unburned matter. It causes such harm.
Therefore, since the blowing flow rate of the secondary air must be limited to an appropriate level, the swirling force or separation force is also naturally limited. The fine particles are therefore not separated by centrifugal force, but are transported into the combustion gas stream. That is, it is extremely difficult to reduce the dust content of the generated gas to a certain level.

(2) Slug re-scattering The conventional examples shown in Figures 4 and 5 have an inclined or horizontal structure, but they all have a concentric ring-shaped slug baffle plate installed at the outlet, which causes the slug to stick to the wall and act as slag. Its purpose is to collect unremoved fly ash and to partition wall slag flow. The slug adhering to the wall surface and the slug adhering to the slug baffle plate flow down the slug buffle plate and reach the slug tap. Therefore, the problem with this type is that the collected slag is re-splattered, and this type is likely to cause re-splatter as described below. That is, in a horizontal combustor, the slag attached to the upper wall surface easily peels off and falls, and is re-dispersed into the gas flow.

The slugs attached to the slug baffle plate are likely to move to the throat section due to swirling force or gravity, that is, the slugs once separated are re-splattered into the high-speed gas flow at the throat section.

As mentioned above, in conventional combustors, fine particles cannot be separated, and the ash separation and collection efficiency is at most 85% or less due to re-entrainment of slag or ash.

The present invention was developed in view of the current situation, and aims to provide a coal gasification combustor that does not cause slag re-scattering, has a high slag removal rate, and has a high slag collection efficiency. be.

[Means for solving problems]

In a coal gasification combustor that burns coal under a high heat load and discharges the ash in the coal in a molten state, the combustor body is a vertical cylinder, and the coal and A primary mixture supply port that supplies an air mixture; a secondary air supply port opened toward the combustor body; a generated gas outlet of a cylindrical body that is erected at the lower part of the combustor body and whose lower part extends to near the bottom of the combustor body; and the generated gas outlet. Coal comprising: a generated gas pipe that is connected horizontally orthogonally to the combustor body and passes through the side wall of the combustor body; and a slag tap that is disposed at the bottom of the combustor body and communicates with a slag bin below. Gasification combustor.

[Operation] Since the combustor is vertical, the slag adhering to the wall flows down along the wall due to gravity, and is prevented from being re-scattering due to separation from the wall. Note that, as in the conventional case, the primary air-fuel mixture is introduced from the end in the axial direction or tangential direction, and the secondary air is introduced in the tangential direction to generate a strong swirling flow.

(2) Most of the ash is removed as slag attached to the wall due to the centrifugal force caused by the swirling flow, but fine ash or slag is not separated by the centrifugal force and is carried by the gas flow, so this combustion gas is removed from the cylinder. The generated gas is guided to the outlet to increase the flow velocity, collides with the bottom of the combustor, changes the direction of the gas flow by 90 degrees or more, is discharged from the generated gas pipe, inertially separates fine particles, and the separated ash or slag is placed in a slag bin. Let it flow down.

As described above, coarse particles are separated by centrifugal force, and fine particles are separated by collision separation by inertial force, and once separated, the slag or ash flows smoothly down the wall surface by gravity, and the slag is discharged without being scattered again. It can be done.

〔Example〕

One embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is an explanatory diagram of the device of this embodiment,
2 is a view taken along the line A-A in FIG. 1, and FIG. 3 is a view taken along the line B-B in FIG. In FIG. 1, 10 is a cylindrical vertical combustor main body, 11 is a primary air-fuel mixture supply port provided at the upper end of the combustor main body 10, and 1
2 is an adjustment cone attached to the primary mixture supply port;
13 is a secondary air supply port arranged in the side wall of the combustor main body 10 in the tangential direction of a circle centered on the axis of the combustor main body 10 in order to give a swirling flow to the gas flow; 14 is a combustor A generated gas outlet 15 is a cylindrical body that stands upright at the bottom of the main body 10 and whose lower part extends to the bottom of the combustor main body 10.
4 is a generated gas pipe which is connected horizontally orthogonally and penetrates the side wall of the combustor body 10, 16 is a cylindrical notch at the lower end of the generated gas outlet, 17 is a slug tap disposed at the bottom of the combustor body 10, and 18 is a This is a slug bin connected to the lower end of the slug tap 17.

The combustor main body 10 has a vertical structure, and a primary air-fuel mixture supply port 11 is installed at the upper end, from which the primary air-fuel mixture is supplied to the combustor main body 10. The degree of expansion of the primary air-fuel mixture is adjusted by moving the adjustment cone 12 up and down. The combustion chamber is maintained at a high temperature, and the primary air-fuel mixture immediately ignites and begins combustion. Here, secondary air is injected from the secondary air supply port 13 through the secondary air duct in a tangential direction at high speed in a virtual circle concentric with the combustor main body 10, forming a strong swirling flow inside the combustor main body 10, Rapid mixing of fuel and air occurs to establish stable and rapid swirl combustion. Note that the amount of air injected into the combustor main body 10 is the amount necessary to maintain the combustion amount and the temperature of the combustor outlet gas at a temperature sufficiently higher than the ash melting point (usually 1500°C or higher, although it varies depending on the coal properties). less than the amount of air. The reason for setting the air amount below the theoretical one is that in a reducing atmosphere, the ash becomes more molten, sludges easily, and can be easily discharged, the calorific value of the generated gas can be increased, and damage to the furnace wall due to too high combustion temperature can be avoided. This is because it is preferable that the temperature of the desulfurization reaction using the SOx absorbent be lower.

Coarse powder in the fuel floats on the wall surface, fine powder floats in the air stream and burns, and molten ash adheres to the peripheral wall, forms a slag layer, flows down, and falls from the slag tap 17 into the slag bin 18. Unlike the horizontal type, slag attached to the wall does not scatter again.

Generated gas that does not contain coarse powder is extracted from generated gas outlet 1.
4, the direction is changed by 90 degrees and the gas is supplied to the outside through the generated gas pipe 15. Here, the flow velocity inside the generated gas outlet 14 is sufficiently fast because the flow path area is narrowed.
The fine ash that has not been separated by centrifugal force also collides with the bottom of the combustor due to inertia and is attached to and separated from the bottom slag layer. The attached and separated slag falls from the cylindrical notch 16 along the bottom surface through the slug tap 17 and into the slag bin 18.

According to the apparatus of this embodiment, the slag adhering to the wall surface of the combustion chamber smoothly flows down and is not scattered again due to peeling, etc., and a high slag removal rate can be obtained. The slug collection efficiency is high due to the slug collection action as described above. Further, since there is no slug buffle plate, the slag adhering to the slug buffle plate will not be scattered again.

[Effect of idea]

According to the present invention, the following effects are achieved.

By making the combustor vertical, the slag adhering to the combustion chamber wall smoothly flows down into the slag bin and will not be scattered again due to peeling, etc.
A high slug removal rate can be achieved.

The inertial force generated by the high flow rate in the generated gas outlet installed inside the combustor is used to collide and separate fine particles against the bottom surface of the combustion chamber, so fine particles can also be separated and removed, resulting in high slag collection efficiency.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a device according to an embodiment of the present invention, Fig. 2 is a view taken along line A-A in Fig. 1, and Fig. 3 is a view taken along line B-B in Fig. 1. 4 is an explanatory diagram of a conventional inclined coal combustor, FIG. 5 is an explanatory diagram of a conventional horizontal coal combustor, and FIG. 6 is an explanatory diagram of a slug buffle plate. 10...Combustor main body, 11...Primary mixture supply port, 13...Secondary air supply port, 14...Generated gas outlet, 15...Generated gas pipe, 17...Slug tap, 18...Slug bin.

Claims (1)

[Scope of utility model registration request] In a coal gasification combustor that burns coal under a high heat load and discharges the ash in the coal in a molten state, the combustor body is a vertical cylinder, and the coal and A primary mixture supply port that supplies an air mixture; a secondary air supply port opened toward the combustor body; a generated gas outlet of a cylindrical body that is erected at the lower part of the combustor body and whose lower part extends to near the bottom of the combustor body; and the generated gas outlet. Coal comprising: a generated gas pipe that is connected horizontally orthogonally to the combustor body and passes through the side wall of the combustor body; and a slag tap that is disposed at the bottom of the combustor body and communicates with a slag bin below. Gasification combustor.