JPS605048A - Cement clinker cooling device - 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 [Technical Field of the Invention] The present invention relates to a device for cooling a baked cement clinker ingot, that is, a clinker cooler, and in particular, a cement clinker cooling device that efficiently recovers heat during cooling of the baked ingot. Regarding.

[Conventional cement clinker cooling system]

After cement clinker is fired in a lorry kiln, it needs to be cooled to a predetermined temperature.

One of the cooling methods is to cool the clinker ingots with cold air while transporting them over a certain distance, but in the case of cement, the energy cost of the product is huge, so cooling heat recovery must be done efficiently. This is requested. Specifically, a portion of the cooling air whose temperature has been raised through heat exchange with the high-temperature baked ingot is introduced into a rotary kiln or calciner, and the heat is recovered as secondary air for combustion.

FIG. 1 shows a conventional clinker cooler. In Fig. 1, 1 is a cooler, 2 is a rotary kiln, 3 is a bleed port for secondary air to the calciner, 4 is an exhaust port for exhaust air, 5 is a clinker,
6 is a cooler grate, 7 is a clinker outlet, 8a to 8d
is a cooling air chamber, 9a to 9d are cooling air blowing fans,
1o is an exhaust fan.

A cement clinker ingot is fired in a rotary kiln 2 at a temperature of around 1400° C. and then introduced into a cooler 1. The clinker 5 that has flowed into the cooler 1 is deposited on the upper part of the grate 6, moves backward in layers on the grate 6, and is discharged from the clinker discharge lower. While moving on this grate, it exchanges heat with the cooling air blown in by fans 92L-9d from air chambers 8a-8d on the lower surface of grate B, and is cooled.

The high-temperature air that exchanges heat with the clinker is recovered at the bleed port 6 to the rotary kiln 2 and the calciner as secondary air for combustion in the rotary kiln 2 and secondary air in the calciner. The air that is not recovered is sent from the exhaust port 4 to the exhaust fan 10.
Exhausted by.

FIG. 2 is a diagram showing the configuration of a grate of a conventional clinker cooler. In FIG. 2, 11 is a fixed grate plate, and 12 is a movable grate plate. Both fixed and movable grate plates are arranged alternately, and the movable grate plate 12 moves back and forth to transport clinker.

[Disadvantages of Conventional Devices] Two characteristics required of the cooler are that the clinker be cooled using a small amount of cooling air, and that the amount of heat of the air recovered as secondary air be as large as possible.

In particular, the latter is important in order to lower the amount of heat required for sintering the cement as a whole, as mentioned above. The volume of recovered air must be kept to the minimum amount required, so in order to increase the amount of heat in the recovered air, it is possible to improve the heat exchange between the clinker and the air and raise the temperature of the air. Te(・ru.

In the conventional cooler shown in FIG. 1, the upper grate of the first cooling air chamber is horizontal in a cross section perpendicular to the clinker flow. According to the measurement results carried out in the kiln, the layer of clinker that falls and accumulates in the upper part of the first cooling air chamber in the kiln has a high center part (as shown in Figure 3). It has been found that the cooling air blown from the cooling air chamber does not pass uniformly through the clinker layer, but flows concentratedly through the thinner layer at the middle end.

This prevents sufficient contact and heat exchange between the clinker and the air, resulting in a disadvantage that the effectiveness of heat recovery by the cooling air in this area is poor.

This uneven passage of air in the clinker falling section has been confirmed in model tests.

The wind speed distribution shown in Figure 3 (bJ) is an example of the model test results.

The mountain-shaped accumulation state near the clinker falling point is caused by the mountain-shaped shape being distorted while the clinker is being transported on the grate.
It will eventually become horizontal, but the clinker will be 1 to 2 times the width of the grate.
Unless it is transported twice the length, it will not be in a horizontal deposition state (・.

In order to prevent the concentrated passage of air at the end, there are measures such as width control that prevents air from passing through a part of the grate at the end, but these are not sufficiently effective methods.

[Object of the present invention]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a cement clinker cooling device that eliminates the drawbacks of the conventional devices. That is, an object of the present invention is to provide a cooling device for cement clinker that improves the contact between the clinker and the cooling air on the grate above the first cooling air chamber and increases the amount of heat exchange in this part. It is in.

[Configuration of the present invention]

As a means for achieving the above object, the present invention resides in that the grate above the cooling air chamber is formed into a mountain shape in its width direction. That is, the present invention provides a grate-type clinker cooling device having a grate that guides clinker discharged from a kiln to a discharge port, and a plurality of cooling air chambers provided below the grate along the moving direction of the clinker. This cement clinker cooling device is characterized in that the grate at least in the upper part of the cooling air chamber on the kiln side is formed into a mountain shape with the center portion being higher than the end portions in the width direction.

In grate-type clinker cooling equipment, the cooling air volume is uneven because, as mentioned above, the clinker layer is thicker in the center (and thinner at both ends), so the cooling air flows intensively at both ends and forms a mountain in the center. This is due to insufficient cooling air passing through the area.

In order to improve this drawback, in the present invention, the grate on which clinker is deposited is shaped so that the center is higher, and the shape matches the shape of the deposited clinker layer. By forming such a grate shape, the thickness of the clinker layer is made uniform, and the passage of cooling air is made uniform, so that heat transfer between the clinker and the air in this part is performed effectively.

That is, in the present invention, the grate at the top of the first cooling air chamber is made into a mountain shape, and the thickness of the clinker layer that falls from the kiln and is deposited on the grate is uniform, thereby preventing unevenness in the flow rate of the cooling air passing through it. However, in the present invention, it is preferable to form the chevron shape so that the central part is high (and both ends are low), so that the height of the central part becomes gradually lower in the flow direction of the clinker.

The present invention will be explained in more detail below based on FIGS. 4 to 7. Fig. 4 shows a grate of a clinker cooler that is an embodiment of the present invention, Fig. 5 is a cross-sectional view taken along the line A-A to Fig. 4, and Fig. 6 is a cross-sectional view taken along the line B-B of Fig. 4. .

In FIGS. 4, 5, and 6, 2o is a great plate, and 21 is a great support.

A grate plate 20 is fixed on a grate support 21. The grate support is composed of movable supports and fixed supports arranged alternately, and the movable supports move back and forth to transport the clinker placed on the top surface.

The height of each grate plate 20 is higher than the adjacent one from each end, and the height of each grate gradually decreases in the direction of flow of clinker until it becomes horizontal.

As the clinker moves on the grate, it is cooled by cooling air blown from the cooling air chamber below the grate. The cooling air that has exchanged heat with the clinker is recovered as secondary air for combustion in the kiln.

When using the grate with the configuration shown above, the clinker deposited on the grate will be in the state shown in Figure 7.The thickness of the clinker layer on the grate will be uniform throughout, and the cooling air will The rate of air passing through the clinker layer approaches uniformity (According to the experimental results from the model test, the wind speed distribution over the clinker layer is the distribution shown in Figure 7 (bJ), indicating that air passes through the clinker layer in an almost uniform manner. I understand.

If the wind speed distribution shown in Figure 6 is improved to the distribution shown in Figure 7, the amount of heat recovery in this area will increase by 15 to 20 Ka.
ol/kg clinker.

[Effects of the present invention]

As described in detail above, the present invention has the grate at the top of the cooling air chamber formed into a mountain shape in the width direction, so that the amount of heat transfer between the clinker and the cooling air at the part where the clinker falls from the kiln can be improved. This makes it possible to bring about a remarkable effect that makes it possible to improve the fuel efficiency of the entire cement firing process.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional riff linker cooler, and Fig. 2 is the same (showing the grate of the conventional clinker cooler.
The figure shows the shape and wind speed distribution of the clinker layer above the first cooling air chamber of a conventional clinker cooler. FIG. 4 shows a clinker cooler grate according to an embodiment of the present invention, FIG. 5 is a sectional view taken along the line A-A in FIG. 4, and FIG.
-B sectional view. Figure 7 shows the clinker 2 of the present invention.
The shape of the clinker layer and the wind speed distribution in the upper part of the first cooling air chamber are shown. Sub-agents 1) Clearance agent Ryo Hagiwara - Figure 3 (α) (b) Figure 7 (b) 293-

Claims (1)

[Claims] In a grate-type clinker cooling device having a grate that guides clinker discharged from the kiln to a discharge port, and a plurality of cooling air chambers provided below the grate along the moving direction of the clinker, at least the kiln side In the width direction of the grate at the top of the cooling air chamber, the center part is higher than the end part (
A cement clinker cooling device characterized by being formed into a mountain shape.