Liquid blast furnace slag granulation method and device thereof

[0017] The specific structure, working principle and implementation manner of the device will be described in detail below with reference to the accompanying drawings.

[0018] The present invention includes a diversion groove 1 , a slag drop port 2 , a dry granulator 3 , a granulation nozzle 4 , and a slag discharge port 5 . The diversion trough 1 is made of refractory materials and is arranged on the top of the granulator. The lowest point of the diversion trough is provided with a slag drop port 2 that communicates with the dry granulator 3. narrow. The liquid blast furnace slag from the blast furnace slag ditch or slag tank flows into the diversion groove 1 , flows out from the slag drop opening 2 at the lower part of the diversion groove 1 and falls vertically into the granulator 3 . The upper part of the granulator 3 is provided with a granulation nozzle 4, and the included angle α between the outlet axis of the granulator nozzle 4 and the vertical direction is 0-90°, so that the granulated medium can obliquely cut the liquid blast furnace slag. The medium in the granulation nozzle 4 is a high-speed airflow carrying solid particles, forming a high-speed gas-solid two-phase flow. The gas-solid two-phase flow for cutting and granulating high-temperature liquid blast furnace slag is used to carry solid particles in the carrier gas flow, which is compressed air or high-pressure inert gas or high-pressure steam. , the pressure of high-pressure steam is 0.1 ~ 10.0MPa. The solid particles carried by the carrier gas stream do not chemically react with the carrier gas stream and remain solid during the flow. During the downward flow of the liquid blast furnace slag, the high-speed gas-solid two-phase flow is blown towards the liquid blast furnace slag in a specific direction, and the liquid blast furnace slag is crushed, rapidly cooled and solidified into small particles during the collision with the high-speed gas-solid two-phase flow. . Since the density and momentum of the solid particles entrained by the airflow increase, the impact force of the airflow on the liquid blast furnace slag can be greatly enhanced, thereby obtaining granulated blast furnace slag particles with a smaller average particle size, which enhances the granulation effect and ensures the granulation effect. Under the premise of reducing the consumption of high-pressure gas, thereby reducing the power consumption of the granulation device and the investment of equipment. The solid particles entrained by the granulated airflow medium can be blast furnace slag particles, sand particles, etc. with a certain particle size distribution, or other solid particles that do not chemically react with the carrier airflow and remain solid during the flow process. Particles with specific components are entrained to change the composition of blast furnace slag, which facilitates the post-utilization of blast furnace slag. Generally, the mass of solid particles with a particle size range of 0.1 to 0.5 mm entrained in the gas-solid two-phase flow accounts for 80% of the total mass of solid particles carried by the gas, that is, 80 wt% of the solid particle size in the gas-solid two-phase flow. Concentrating on 0.1-0.5mm, only 10 wt% of the solid particles have a particle size smaller than 0.1 mm, and about 10 wt% of the solid particles have a particle size larger than 0.5 mm.

[0019] In order to facilitate the smooth discharge of slag particles from the granulator 3, the bottom of the granulator is inclined and the slag discharge port is located at the lowest part of the bottom of the granulator. The granulated particles are discharged from the granulator 3 from the slag discharge port 5 and enter the subsequent heat exchange device.

[0020] Two or more granulating nozzles can be arranged, and the granulating nozzles can be arranged on one side, or symmetrically, or circumferentially arranged with the vertical line of the center of the slag outlet as the center. figure 1 This is a schematic diagram of an embodiment of one-side arrangement of the granulation nozzles of the liquid blast furnace slag dry granulation device. A single or two to more than two granulation nozzles are arranged on one side of the upper part of the granulator. If there are more than two, the granulation nozzles are In order to be arranged in parallel up and down, a group of granulating nozzles is formed. figure 2 It is a schematic diagram of the symmetrical arrangement of the granulating nozzles of the liquid blast furnace slag granulation system. Two or more granulating nozzles are arranged on both sides of the upper part of the granulator and are symmetrically arranged; the granulating nozzles on the same side are arranged in parallel up and down, forming a Group of granulating nozzle groups. More than two nozzles or nozzle groups can also be arranged circumferentially with the center vertical line of the slag opening as the center.

[0021] After granulation, the blast furnace slag particles discharged from the slag discharge port enter the subsequent heat exchange device for heat exchange to generate hot air or steam for production use or power generation; there is also hot gas containing dust discharged from the slag discharge port, which contains heat It can be recycled. In order to prevent dust pollution, the gas is discharged after being dedusted by a dust collector.

[0022] The principle of the blast furnace slag dry granulation method involved in the present invention is that high-speed gas-solid two-phase flow is formed by using positive pressure gas entrained with solid particles, and under the guidance of an adjustable nozzle, high-speed impact on the flowing blast furnace slag , the high temperature liquid slag is cut horizontally or obliquely, and the momentum exchange between the gas-solid two-phase jet and the flowing slag makes the liquid slag break into granules; in the process of the liquid slag breaking into particles and falling in the air Due to the effect of radiation, the surface of the blast furnace slag after fragmentation solidifies rapidly, and the dry granulation process is completed. By controlling the flow rate of liquid slag, and controlling the direction of gas-solid two-phase flow, gas-solid flow rate and gas-phase pressure, blast furnace slag solid particles with different particle size ranges can be obtained for subsequent heat utilization.