JPS632880Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for cooling a baked cement clinker ingot, that is, a clinker cooler, and particularly to a device that efficiently recovers heat during cooling of the baked ingot.

Generally, after cement clinker is fired in a rotary 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 a certain distance, but in the case of cement, the cost of energy accounts for a huge amount of the product price, so cooling heat can be recovered efficiently. It is requested to do so. Specifically, a portion of the cooling air that has been heated through heat exchange with the high-temperature baked ingot is introduced into the rotary kiln and calciner, and the heat is recovered as secondary air for combustion.

A conventional clinker cooler, as shown in Fig. 1, includes a cooler body 1, a rotary kiln 2, a bleed port for secondary air to the calciner, 4 an exhaust port for exhaust air, and a clinker 5. 6 is a cooler grate, 7 is a clinker outlet, 8a-8d are cooling air chambers, 9a-
9d is a cooling air blowing fan, 10 is an exhaust fan, and the cement clinker ingot is fired in the rotary kiln 2 at a temperature of around 1400°C and then introduced into the clinker cooler 1. The clinker 5 that has flowed into the cooler 1 is deposited on the upper part of the grate 6, and moves backward on the grate 6 in a layered manner.
The clinker is discharged from the clinker discharge port 7. While moving on this grate, the clinker 5 is cooled by exchanging heat with the cooling air blown in by the fans 9a to 9d from the air chambers 8a to 8d on the lower surface of the grate 6.

The air, which has become high in temperature through heat exchange with the clinker, is recovered at the bleed port 3 to the rotary kiln 2 and the calciner as secondary air for combustion in the rotary kiln 2 and secondary air for the calciner. The unrecovered air is exhausted from the exhaust port 4 by an exhaust fan 10.

FIG. 2 is a diagram showing the configuration of a grate of a conventional clinker cooler. In the figure, 11 is a fixed grate plate, and 12 is a movable grate plate. Both the fixed and movable great plates are arranged alternately, and the movable great plate 11
The clinker is transported by moving back and forth.

The characteristics required of the cooler include two points: cooling the clinker using a small amount of cooling air, and maximizing the amount of heat of the air recovered as secondary air.

The second point in particular is important, as mentioned earlier, in order to lower the amount of heat required for firing the cement as a whole. The volume of recovered air must be kept to the minimum required for fuel combustion, so in order to increase the heat content of recovered air, it is necessary to improve the heat exchange between the clinker and the air and increase the temperature of the air. However, 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 such coolers, the layer of clinker that falls from the kiln to the top of the first cooling air chamber and accumulates is high in the center and high at both ends, as shown in Figure 3a. 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 both ends. This hinders 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 condition in which air passes through the clinker's falling part unevenly has been confirmed in model tests. Third
The wind speed distribution shown in Figure b is an example of the model test results.

The mountain-shaped accumulation near the point where clinker falls is such that the mountain-shaped shape collapses as the clinker is transported over the grate, and eventually becomes horizontal, but the clinker must be transported for a length that is 1 to 2 times the width of the grate. In this case, horizontal deposition will not occur.

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 methods have not been sufficiently effective.

This invention was made in view of the drawbacks of the conventional one, and includes a grate that guides clinker discharged from the kiln to the discharge port, and a plurality of cooling air chambers provided below the grate along the direction of movement of the clinker. In the grate-type clinker cooling device having at least the grate at the top of the cooling air chamber on the kiln side, the grate in the upper part of the cooling air chamber on the kiln side is formed into a stepped shape in the width direction with the central part having a flat part higher than the end parts. According to the present invention, the shape of the grate on which clinker is deposited is made high at the center, and the shape is close to the shape of the clinker layer deposit, thereby increasing the amount of clinker transported and breaking down the mountain quickly. It also has various advantages such as making the thickness of the clinker layer uniform and making the passage of cooling air uniform so that heat transfer between the clinker and the air can be carried out effectively in this area. It is possible to have a certain effect.

Embodiments of the present invention will be described below with reference to FIGS. 4 to 7.

In the figure, 20 is a great plate, and 21 is a great support. A grate plate 20 is fixed on a grate support 21. The grate support 21 has movable supports and fixed supports arranged alternately, and the movable supports move back and forth to transfer the clinker placed on the upper surface thereof. The center part of the grate plate 20 is one step higher in plane than both end parts, and the high grate in the center part ends in the third to fifth examples, and thereafter, the grate has the same height as both end parts.

While moving on the grate in this manner, the clinker is cooled by the 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.

It is appropriate that the height H and width of the raised central part of the grate be approximately 1/60LH1/10L 1/6L11/2L with respect to the cooler width L, as shown in Figure 5. .

According to this embodiment configured in this way, the clinker deposited on the grate plate 20 is in the state shown in FIG. 7a. The thickness of the clinker layer on the grate plate 20 becomes uniform throughout, and the rate of passage of cooling air also approaches uniformity. According to the experimental results of the model test, the wind speed distribution on the clinker layer is as shown in FIG. 7b, indicating that air passes through the clinker layer in a nearly uniform manner. When the wind speed distribution shown in FIG. 3b is improved to the distribution shown in FIG. 7b, the increase in heat recovery in this part will be 15 to 20 kcal/Kg clinker.

In addition, since the height of the front surface of the great plate 20 at the center is higher than that of the great plates 20 at both ends, the amount of clinker transferred in this area increases, resulting in a pile of clinker in the center at the clinker outlet. This increases the amount of clinker that is being transported downstream, increases the effect of breaking down the piles, makes it possible to greatly improve the amount of heat recovery, and even improves the fuel consumption of cement firing. It is possible to achieve the desired effect.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing a conventional clinker cooler;
Figure 2 is an explanatory diagram of the main parts showing the grate in Figure 1, Figures 3a and b are explanatory diagrams showing the clinker layer shape and wind speed distribution in the upper part of the first cooling air chamber, respectively; Fig. 4 is an explanatory diagram of main parts showing an embodiment of the present invention, Fig. 5 is a sectional view taken along line A-A in Fig. 4, Fig. 6 is a sectional view taken along line BB in Fig. 4, and Figs. 7 a and b. FIG. 4 is an explanatory diagram showing the shape of the clinker layer in the upper part of the first cooling air chamber and the wind speed distribution, respectively. 20...Great Plate, 21...Great Support.

Claims (1)

[Scope of utility model registration request] 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,
A clinker cooling device characterized in that a grate in the upper part of a cooling air chamber on at least the kiln side is formed into a stepped shape in the width direction with a flat part higher at the center than at the ends.