A method and device for spraying and granulating blast furnace molten slag

Abstract

A method and equipment for spray granulation of blast furnace melted slag are disclosed. The equipment includes a melted slag tank, a melting tank and a Venturi type internal mixing two-phase flow device. The outlet of the melting tank is connected to a top melted slag inlet of the Venturi type internal mixing two-phase flow device through a pipeline. The bottom of the melted slag inlet is communicated with a receiving chamber. The inner side of a shrinking type material supplying spray nozzle is connected to a high-temperature flue gas inlet. The high-temperature flue gas inlet is connected to an outlet of an air compressor through a pipeline. An inlet of the air compressor is connected to a gas outlet at the top of the melting tank. An outlet of the receiving chamber is connected to oneend of a mixing chamber through a mixing-chamber inlet, and the other end of the mixing chamber is communicated with an atomizing and mixing chamber. The atomizing and mixing chamber is connected to an external air blower and a high-pressure water pump through an atomizing air inlet and an atomizing water inlet respectively. An outlet of the atomizing and mixing chamber is provided with an atomizing spray nozzle. The equipment is simple in structure, free of moving parts, suitable for long-term stable running, low in maintenance amount and convenient to use. Recovery of the blast furnace melted slag and reasonable utilization of waste heat are achieved mainly, thus achieving maximum benefit.

Description

technical field [0001] The invention relates to the technical field of blast furnace molten slag granulation equipment, in particular to a method and device for spraying and granulating blast furnace molten slag. Background technique [0002] Blast furnace molten slag granulation can be divided into wet type and dry type. The wet type granulation adopts the method of water quenching granulated molten slag. Its granulation effect is good, the content of glass is high, and the crystallinity is low, which is conducive to the mixing of cement and concrete. However, the sensible heat and latent heat of the molten high-temperature slag cannot be recycled, and a large amount of water is consumed during water quenching, and the moisture in the granulated slag must be dried during grinding. [0003] Dry granulation The methods of quenching dry granulated blast furnace slag that have undergone industrial tests include drum drum method, wind quenching method, centrifugal granulation me...

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Problems solved by technology

[0002] Blast furnace molten slag granulation can be divided into wet type and dry type. The wet type granulation adopts the method of water quenching granulated molten slag. Its granulation effect is good, the content of glass is high, and the crystallinity is low, which is conducive to the mixing of cement and concrete. However, the sensible heat and latent heat of the molten high-temperature slag cannot be recycled, and a large amount of water will be consumed during water quenching, and the moisture in the granulated slag must be dried during grinding.

[0003] Dry granulation The methods of quenching dry granulated blast furnace slag that have undergone industrial tests include drum drum method, wind quenching method, centrifugal granulation method, and chemical granulation method; the drum method has low processing capacity and equipment operation rate, the ability to crush molten slag is insufficient, the particle size distribution range of the crushed slag is large, the heat exchange area with the heat exchange medium is small, the heat exchange efficiency is low, the cooling speed is insufficient, and the vitreous content of the granulated slag is low; the air quenching method granulation The particle size range of molten slag is too wide, and the speed of air-cooled slag is slow, resulting in large power consumption and large equipment size. The centrifugal granulation method has uniform granulation particle size, narrow particle size distribution range, and small flow loss. It is currently a promising granulation method. ; but it has higher requirements for mechanical energy, the higher the speed, the better the granulation, which puts forward higher requirements for the stability of the motor and the shaft, especially at high temperatures, and its centrifugal granulation cone angle is larger , it is not convenient to exchange heat with the heat exchange medium

[0004] The above-mentioned dry granulation process generally pays attention to the utilization of blast furnace slag, but ignores the huge heat energy contained in it.

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