(IV) Influence of material layer thickness The optimum thickness of the cooling material layer shall be determined by experiment according to the cooling equipment used. As can be seen from Fig. 6, in the case where the amount of air is fixed, the cooling time is proportional to the 0.9th power of the thickness of the layer. Obviously, in the design and production, the height of the material layer must be kept as high as possible, the particle size segregation should be avoided, the local abrupt oxidation should be prevented, the air flow distribution should be uniform and the air leakage should be reduced, and the sinter can be cooled more uniformly. One of the difficulties in sinter cooling is to reduce the temperature of the bulk center so that after the large block is discharged from the chiller, it will not burn the conveyor belt due to overheating at the center. Research and production practices have shown that the cooling time is related to the heat exchange rate of the surface of the sintered ore block and the heat transfer rate from the center of the block to the surface, which is proportional to the thickness of the layer of 0.9 and inversely proportional to the velocity of the gas stream. Terminal Fender,Tug Boat Bumpers,Tug Boat Rubber Dock,Tugboat Special Fenders Zhejiang Hengbang Rubber Products Co., Ltd. , https://www.hbrubberproducts.com
When the wind system has certain capacity and other conditions are the same, the thicker the material layer, the greater the resistance of the air through the material layer, which reduces the cooling rate; and if the material layer is too thin, it is prone to quenching or "air short circuit". Affects cooling effect and sinter quality.
The thickness of the domestically cooled cooling layer is generally about 300 mm; the thickness of the blast cooled layer is 1.0 to 1.55 m. Fig. 5 shows the relationship between the thickness of the layer and the cooling productivity. Figure 6 shows the relationship between the thickness of the layer and the cooling time. 
(5) Effect of material layer temperature The temperature at which the sinter is removed from the tail of the sintering machine is usually 600-800 ° C. When the sintering process is not normal or the fuel is too much, the particle size is too coarse, and the residual carbon is too much, it will be The combustion continues on the cooler, which seriously affects the cooling effect. Therefore, controlling the sintering end point is closely related to the cooling effect.
When the cooling machine is fixed, the air volume and the wind pressure are constant values, so to a certain extent, the lower the sinter temperature charged into the cooling machine, the higher the output of the cooling machine; vice versa. However, experiments and practices have demonstrated that the cooling rate of sintered ore from 700 to 800 ° C to 400 ° C is very fast. That is to say, in the case where the sintering is normal, the cooling time can be assumed to be unaffected by the initial temperature.
(Vi) Effect of layers and uniformity of the production practice has proved that oxidation of the magnetic iron ore during cooling evolution of considerable heat, but does not make a lot of cooldown, simply raising the temperature of exhaust emissions. Therefore, from the viewpoint of practical operation, when the air volume of the cooling fan is selected, such an increase in temperature must be considered. [next]
A typical cooling curve for a sintered ore that has just been sintered is shown in Figure 7.
(VII) Cooling time There are two main aspects affecting the cooling efficiency of sinter:
(1) Heat is transferred from the sintered ore block to the appearance of the sintered ore block by conduction.
(2) Heat is transferred from the sinter surface to the cooling medium by convection, radiation and conduction.
That is to say, the cooling time of the sintered ore is related to the heat transfer strength of the cooling layer, the diameter of the sintered ore particles, the porosity of the layer, the exhaust gas velocity and the like. Figure 8 shows a typical cooling curve for different temperatures, exhaust gas flow, sinter particle size composition, and layer thickness, and the cooling time under specific conditions can be seen.