JPH044495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ash extraction device that is disposed directly under the bottom of a coal-fired boiler or the like and cools and discharges falling clinker.

To explain a conventional example of an ash extraction device installed in a coal-fired boiler, as shown in FIGS.
Seal plates 3, 3 are installed vertically from the hearth bottom 1a, and the clinker (hearth ash) falling from the hearth bottom 1a is rapidly cooled in the cooling water b held in the hopper 2, and the opening/closing is performed. The water storage hopper type opens the valve 2b and takes out the cooled clinker from the discharge port 2a, and the furnace bottom 1a as shown in Fig. 2A and B.
A trough 5 holding cooling water b is arranged directly below the
Seal plates 7, 7 are hung vertically from the hearth bottom 1a,
It can be broadly classified into a mechanical continuous discharge type in which a conveyor flight 6 disposed on a trough 5 is run in the direction of the arrow, and the clinker that has fallen is transported while being cooled and discharged from a rising portion 5a.

In addition, when coal is used as fuel, there is a risk of generating clinker that explodes when rapidly cooled depending on the type of coal, that is, the ash component. When the clinker is slowly cooled, it becomes very hard, making it difficult to discharge and crushing with a clinker crusher.

However, in the conventional ash extraction device, the water storage hopper type cannot avoid clinker being rapidly cooled, and cannot be used when the fuel is coal that generates clinker that may explode. In addition, the mechanical continuous discharge type has the advantage of being able to discharge clinker continuously and efficiently, but it is also possible to reduce the depth of the cooling water in the trough to gradually cool the clinker and prevent explosions. However, in this case, the upper part of the huge clinker cannot be cooled and the clinker cannot be cooled sufficiently before being discharged.
Since the clinker becomes very hard and difficult to discharge and crush, reducing the depth of the cooling water has its own limits and has the drawback of insufficient explosion prevention.

The present invention was developed in view of the above-mentioned circumstances, and includes a trough that holds cooling water placed directly below the bottom of the furnace, and a conveyor flight placed on the trough that runs. In the ash extraction device for discharging clinker while cooling it, the depth of the cooling water in the trough is configured to be a shallow slow cooling area just below the furnace bottom and a deep quenching area at a position outside the furnace bottom. Its purpose is to prevent the clinker from exploding and solidifying by slowly cooling the clinker using the cooling water held in the trough and then rapidly cooling it, thereby eliminating the above-mentioned drawbacks. The point is that it provides an ash extraction device.

The present invention has the above-mentioned configuration, in which a trough holding cooling water is disposed directly below the bottom of the furnace, and the clinker is cooled and discharged by running a conveyor flight disposed on the trough. In the ash extraction device, the depth of the cooling water in the trough is configured to be a shallow slow cooling area just below the hearth bottom and a deep quenching area at a position outside the hearth bottom, so that the clinker that has fallen from the hearth bottom is , it is slowly cooled by cooling water just below the furnace bottom to a low temperature, and then rapidly cooled at a position away from the furnace bottom, and is sufficiently cooled, explosions are prevented, and solidification can be suppressed.
Clinker is discharged smoothly and post-processing is facilitated, resulting in significantly improved ash removal performance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. An embodiment of the present invention is shown in Figures 3 to 5, in which 1 is a coal-fired boiler, 1a is the bottom of the furnace, and directly below the bottom 1a is a trough that holds cooling water b. 10 is disposed, and a conveyor flight 11 is disposed which is operated to travel in the direction of an arrow (to the right in the figure) on the trough 10.
The clinker a that has fallen from the hearth bottom 1a as the clinker 1 travels is transferred to the right side in the figure while being cooled by the cooling water b, and is discharged from the rising portion 10a of the trough 10. Further, seal plates 12, 12 are vertically installed from the hearth bottom 1a, and the lower ends of the seal plates 12, 12 are immersed in the cooling water b, thereby sealing between the hearth bottom 1a and the ash removal device.

Furthermore, in this embodiment, as shown in FIG. 3, the concave bottom portion 10b of the trough 10 is provided at a position away from directly below the hearth bottom 1a, and the bottom surface of the trough 10 directly below the hearth bottom is different from the conventional device. The trough 10 has a relatively high height, and the trough 10 has a structure in which the depth of the cooling water b is formed in a shallow slow cooling region at a portion directly below the furnace bottom, and a deep quenching region at a position away from directly below the furnace bottom, that is, the concave bottom portion 10b. . Further, along with the formation of the concave bottom portion 10b, the conveyor flight 1
1 is also disposed at the concave bottom portion 10b so as to run low by a guide roller 15. The illustrated embodiment of the present invention has the above-described configuration, so that when the conveyor flight 11 on the trough 10 is moved in the direction of the arrow (to the right in the figure) by a drive mechanism not shown, the bottom of the furnace is The clinker a that has fallen from 1a forms a shallow furnace bottom 1a.
The clinker a enters the trough 10 directly below and is cooled while being transferred to the right side in the figure and gradually cooled. When the clinker a comes out from directly below the furnace bottom, it enters the deep cooling water b in the concave bottom 10b of the trough 10 and is rapidly cooled to the desired level. It is cooled down to temperature and discharged from the rising portion 10a side.

Therefore, in this example, since the clinker a is initially slowly cooled to a relatively low temperature and then rapidly cooled, there is no risk of explosion even if the clinker is large. Because the clinker is then rapidly cooled, the clinker condensation is significantly suppressed.
Discharge is performed smoothly and post-processing pulverization is also facilitated.

Furthermore, since the clinker is slowly cooled and then rapidly cooled as described above, the clinker can be sufficiently cooled in the same manner as before, and the clinker, that is, the ash removal efficiency, is not particularly reduced, and the ash removal efficiency is the same as that of the conventional equipment. It has excellent ash removal performance, and the discharge is good as described above.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1A is a longitudinal cross-sectional view showing an example of a conventional ash removal device, FIG. 1B is a cross-sectional view of the - part of FIG. 1A,
Figure 2A is a vertical sectional view showing another conventional example, Figure 2B
2A is a sectional view of the minus part in FIG. 2A, FIG. 3 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 4 is a sectional view of the minus part in FIG. - is a sectional view of the portion. 1: Boiler, 1a: Hearth bottom, 10: Trough, 10
b: concave bottom, 11: conveyor flight, 12: seal plate, 15: guide roller, a: clinker, b: cooling water.

Claims (1)

[Claims] 1. In an ash extraction device in which a trough holding cooling water is disposed directly below the furnace bottom and clinker is cooled and discharged by running a conveyor flight disposed on the trough, the cooling water in the trough is disposed. The ash extraction device is characterized in that the water depth is configured such that a shallow slow cooling region is located directly below the furnace bottom and a deep rapid cooling region is located outside the furnace bottom.