WO2023184962A1

WO2023184962A1 - Drum quick-cooling dry treatment device for blast furnace slag for use in waste heat recovery

Info

Publication number: WO2023184962A1
Application number: PCT/CN2022/128585
Authority: WO
Inventors: 凌祥; 黄博厚; 刘威宏; 包恒兴
Original assignee: 南京工业大学
Priority date: 2022-04-02
Filing date: 2022-10-31
Publication date: 2023-10-05
Also published as: CN114774596A

Abstract

A drum quick-cooling dry treatment device for blast furnace slag for use in waste heat recovery, comprising a blast furnace slag trough, multiple sets of cooling granulation drums and a heat exchanger. The cooling granulation drum comprises an inner drum, an outer drum, a cooling coil and a heat conduction medium. The closed space between the inner drum and the outer drum is filled with the heat conduction medium. The cooling coil is embedded in the heat conduction medium in the closed space between the inner drum and the outer drum and is completely isolated from the slag. When the device works, the drum rotates, the slag flows naturally down from a width-adjustable notch at the bottom of the blast furnace slag trough and is attached to the surface of the outer drum. Heat is transferred from the heat conduction medium between the inner drum and the outer drum to the cooling coil embedded therein, and is taken away by a coolant in the cooling coil. The slag is rapidly cooled into a vitreous state, is crushed by the outer drum of an engaged gear roller, and enters the heat exchanger for waste heat recovery. During work, molten slag vitrification and slag granulation collection are carried out simultaneously to realize continuous production. The slag can be efficiently recycled, and the waste of high-quality waste heat resources of the liquid slag is effectively reduced.

Description

A blast furnace slag drum quick-cooling dry treatment device for waste heat recovery

Technical field

The invention belongs to the technical field of metallurgical high-temperature slag treatment, and specifically relates to a blast furnace slag drum quick-cooling dry treatment device that separates slag from water, has a cooling tube that is not in direct contact with the slag, and is used for waste heat recovery.

Background technique

Blast furnace slag is the main by-product of the iron and steel metallurgical industry. Under the current production process conditions, more than 0.3t of blast furnace slag is produced for every 1t of pig iron produced. Its temperature is around 1450~1550℃. Each ton of slag contains about 1.8MJ of waste heat. For recycling. China is currently the world's largest steel producer. In 2020, the country's total pig iron production was 887.524 million tons. According to the industry average, it is estimated that 266 million tons of slag will be produced. The heat contained in it is equivalent to the burning of 16.365 million tons of standard coal (1 The heat generated by the combustion of a ton of standard coal is 29307.6kJ). If the heat energy in high-temperature slag can be effectively recycled, tens of thousands of tons of atmospheric pollutants such as CO2, _SO2 , and _H2S will be reduced. At present, the methods for treating high-temperature slag mainly include wet method and dry method. The wet method, that is, the water quenching method, is currently the most widely used method. Although this method has the advantages of small particle size and high vitreous content, it wastes a lot of water resources and high-grade heat energy, and also produces sulfur-containing gas and pollutes the environment. Dry methods include rotary cup method, drum method, rotating disk method, etc., which mainly achieve the purpose of granulating slag through the dual effects of centrifugal force and air cooling. Due to the low efficiency of air cooling and the uncontrollability of high-temperature slag flow patterns, the traditional dry processing method results in poor final product quality. The content of glass particles that can be used for cement production is relatively low, and the equipment structure of this method is complex and unstable. Not good.

Contents of the invention

In view of the deficiencies in the prior art, the present invention provides a blast furnace slag drum quick-cooling dry processing device for waste heat recovery. When the device is running, high-temperature molten slag flows downward through the slot at the bottom of the blast furnace slag tank and adheres to the cooling granulation drum below. The cooling granulation drum is composed of an inner and outer cylinder. Both ends of the inner and outer cylinder are sealed, and the middle closed cavity is filled. Thermal medium. The coolant flows in a closed cooling coil, which is buried in the heat transfer medium between the inner and outer cylinders. The high-temperature slag adheres to the surface of the outer cylinder, and the heat is transferred from the heat-conducting medium between the inner and outer cylinders to the cooling tubes buried in it, and is taken away by the coolant in the cooling tubes. The high-temperature slag quickly cools to about 600°C to form a glassy state. The cooling granulating drum continues to rotate. When it rotates to a certain angle, the two intermeshing outer drums squeeze and crush the slag, and the slag falls into the heat exchanger to recover waste heat.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A blast furnace slag drum quick-cooling dry treatment device for waste heat recovery, which is characterized in that it includes a blast furnace slag tank installed on a bracket, several sets of cooling granulation drums and heat exchangers;

The high-temperature molten slag flows downward through the adjustable-width slot set at the bottom of the blast furnace slag tank and adheres to the outer wall of the cooling granulation drum. The high-temperature molten slag is cooled into glassy slag. The glassy slag is arranged in several groups in the vertical direction. The cooling granulation roller is squeezed and crushed in sequence, and finally enters the heat exchanger for waste heat recovery;

Wherein, the cooling granulation rollers are arranged in pairs, and each cooling granulation roller includes an outer cylinder, an inner cylinder and a cooling coil. The closed space formed between the outer cylinder and the inner cylinder is filled with heat-conducting medium, so The cooling coil is embedded in the heat transfer medium.

In order to optimize the above technical solutions, specific measures taken also include:

Further, the inner layer of the blast furnace slag tank is an insulating coating, the middle layer is a high-temperature resistant material, and the outer layer is thermally insulated.

Further, the surface of the outer cylinder is processed with crushing gear teeth, and two outer cylinders in the same group mesh with each other.

Furthermore, the inner cylinder is axially penetrated by a main shaft, and the main shaft is driven by a driving motor, thereby driving the rotation of the entire cooling and granulating drum.

Further, the cooling liquid flows in the cooling coil, and the cooling liquid flows into the cooling coil through the cooling liquid inflow pipe, the inflow main pipe and the inflow branch pipe, and the cooling liquid in the cooling coil flows out through the outflow branch pipe and the cooling liquid outflow pipe in sequence; The main inflow pipe is fixedly sleeved on the part of the main shaft that extends out of the inner cylinder, and the coolant inflow pipe is connected to the main inflow pipe through the inflow rotary joint; the main shaft is partially hollow, and the outflow branch pipe is connected to the main inflow pipe through the hollow part of the main shaft and the outflow rotary joint. The cooling liquid outflow pipes are connected; wherein, the cooling liquid inflow pipe, the inflow rotary joint and the cooling liquid outflow pipe do not rotate with the main shaft.

Further, an expansion chamber is provided on one side of the cooling granulation drum. Two expansion chambers in the same group are arranged in a staggered manner. The expansion chamber is connected to the closed space between the outer cylinder and the inner cylinder and is used to accommodate the expansion of the heat-conducting medium. the subsequent volume.

Further, the thermal conductive medium is tin or graphite mixed with ceramic glue.

Further, the heat exchanger is placed directly below the cooling granulation drum, and the slag crushed by the cooling granulation drum enters the heat exchanger through the collection port. The heat exchanger is provided with an oscillation mechanism.

The beneficial effects of the invention are: when the device is working, the slag vitrification and slag granulation collection processes are carried out simultaneously to realize continuous production; the cooling liquid and the slag are completely separated, and the cooling tube is not in direct contact with the slag to avoid It eliminates the leakage of coolant due to thermal fatigue damage of the cooling pipe, essentially eliminating the risk of contact between the coolant and the slag; it can efficiently recycle the slag, effectively reducing the serious waste of high-quality waste heat resources of liquid slag, and the heat energy recovery efficiency reaches 70%, which is of great significance to the waste heat recovery and efficient utilization of high-temperature slag.

Description of drawings

Figure 1 is a schematic structural diagram of the blast furnace slag drum rapid cooling dry processing device of the present invention.

Figure 2a is a schematic structural diagram of a blast furnace slag tank according to the present invention.

Figure 2b is a schematic structural diagram of the notch at the bottom of the blast furnace slag tank according to the present invention.

Figure 3 is a schematic structural diagram of the cooling granulation drum of the present invention.

Figure 4a is a cross-sectional view of the flow path of the cooling coil in the cooling granulation drum of the present invention.

Figure 4b is a schematic diagram of the flow path of the cooling coil in the cooling granulation drum of the present invention.

Figure 5 is a schematic diagram of the present invention's operation of granulating and crushing slag.

The reference signs are as follows: 1-blast furnace slag tank; 1.1-notch; 2-bracket; 3-driving motor; 4-cooling granulating drum; 4.1-coolant outflow pipe; 4.2 outflow rotary joint; 4.3 inflow rotary joint; 4.4 Coolant inflow pipe; 4.5 inflow main pipe; 4.6-cooling coil; 4.7-outflow branch pipe; 4.8-inflow branch pipe; 4.9-outer cylinder; 4.10-heat transfer medium; 4.11-expansion chamber; 4.12-inner cylinder; 4.13-spindle; 5 -Heat Exchanger.

Detailed ways

The present invention will now be described in further detail with reference to the accompanying drawings.

The blast furnace slag drum quick-cooling dry processing device shown in Figure 1 includes a blast furnace slag tank 1, a bracket 2, a drive motor 3, a cooling granulating drum 4 and a heat exchanger 5. The blast furnace slag tank 1 is placed at the bottom of the high-temperature slag pool, and the cooling granulation drum 4 is used to quickly cool the liquid slag flowing down from the blast furnace slag tank 1 to vitrify and pulverize it. During operation, when high-temperature liquid slag flows down through the blast furnace slag tank 1 at the bottom of the slag pool, it adheres to the surface of the cooling granulation drum 4. A cooling coil 4.6 is arranged in the cooling granulation drum 4, and the coolant is in the cooling coil 4.6. Continuously flowing, the molten slag rapidly cools down under the action of the coolant in the coil and forms a glassy state that adheres to the surface of the cooling granulation drum 4. The cooling granulating drum 4 is driven by the drive motor 3, which adopts a reduction motor, which can adjust the motor speed according to the slag flow and temperature. The reduction motor is fixed on the machine base through the machine feet. Under the control of the drive motor 3, the cooling granulating drum 4 continues to rotate. When it rotates to a certain angle, the glassy slag attached to the surface of the cooling granulating drum 4 is extruded and crushed by the intermeshing surfaces of the cooling granulating drum 4, forming a The powder then falls into heat exchanger 5.

The structure of the blast furnace slag tank 1 is shown in Figures 2a and 2b. The inner layer of the blast furnace slag tank 1 is an insulating coating, the middle is a high-temperature resistant material, and the outer layer is thermally insulated. The bottom of the blast furnace slag tank 1 is provided with an adjustable-width slot 1.1, which can adjust the opening to control the flow of high-temperature slag and ensure that the high-temperature slag can form a uniform film on the surface of the cooling granulation drum 4.

The structure of the cooling granulation drum 4 is shown in Figure 3. A cooling coil 4.6 is arranged inside the cooling granulation drum 4, and the cooling coil 4.6 is spirally arranged between the outer cylinder 4.9 and the inner cylinder 4.12. The space between the outer cylinder 4.9 and the inner cylinder 4.12 is filled with heat transfer medium 4.10, and the cooling coil 4.6 is buried in the heat transfer medium 4.10. The inner cylinder 4.12 is axially penetrated by a main shaft 4.13. The main shaft 4.13 is driven by the drive motor 3, which in turn drives the rotation of the entire cooling and granulating drum 4. Coolant continues to flow in the cooling coil 4.6. The coolant flows into the cooling coil 4.6 through the coolant inflow pipe 4.4, the main inflow pipe 4.5 and the inflow branch pipe 4.8. The coolant in the cooling coil 4.6 flows out through the outflow branch pipe 4.7 and the coolant in sequence. Outflow from tube 4.1. The flow trajectory of the coolant in the pipe is shown in Figures 4a and 4b.

Specifically, the inflow main pipe 4.5 is fixedly sleeved on the part of the main shaft 4.13 extending out of the inner cylinder 4.12, and the coolant inflow pipe 4.4 is connected to the inflow main pipe 4.5 through the inflow rotary joint 4.3. One end of the spindle 4.13 has a hole, and the formed hollow portion serves as a section of flow path for the coolant. The outflow branch pipe 4.7 is connected to the hollow part of the spindle 4.13, and the orifice is connected to the coolant outflow pipe 4.1 through the outflow rotary joint 4.2. When the spindle 4.13 rotates, the coolant inflow pipe 4.4, the inflow rotary joint 4.3 and the coolant outflow pipe 4.1 do not rotate accordingly.

Thermal conductive medium 4.10 requires the use of thermal conductive materials with good heat transfer properties, which can be tin, graphite mixed with ceramic glue, etc. The melting point of tin is 231.89°C, and the cooling granulation drum 4 operates at a temperature of about 600°C, so tin will undergo a phase change from solid to liquid, while the boiling point of tin is 2260°C, which is much higher than the working temperature, so it is very Stable and will not cause danger of boiling. Therefore, when the thermal conductive medium 4.10 is a metal such as tin, due to the volume change caused by the phase change during operation, an expansion cavity 4.11 needs to be provided on one side of the cooling granulation drum 4 to avoid the phase change of the thermal conductive material causing volume expansion and damage to the drum.

The working principle of the cooling granulation drum 4 is: the coolant continuously enters the cooling coil 4.6 from the coolant inflow pipe 4.4, and flows out from the coolant outflow pipe 4.1. When the high-temperature molten slag flows to the surface of the outer cylinder 4.9, the high-temperature molten slag exchanges heat with the coolant in the cooling coil 4.6 through the heat transfer medium 4.10. The high-temperature molten slag quickly cools down to form a glassy state, and the heated coolant flows out through the coolant. Outflow from tube 4.1. The cooling granulating drum 4 rotates under the control of the drive motor 3. The drum speed can be adjusted according to the amount of slag and the cooling speed. When the cooling granulating drum 4 rotates to a certain angle, the high-temperature slag cools to form a glassy state, and the glassy slag adheres to it. On the surface of the outer cylinder 4.9, as the roller continues to rotate to the meshing position of the two outer cylinders 4.9, it is then crushed and granulated.

An implementation example of the present invention is shown in Figure 5. The blast furnace slag tank 1 is connected to the slag pool. High-temperature molten slag flows along the blast furnace slag tank 1. There is a slot 1.1 at the bottom of the blast furnace slag tank 1. The width of the slot 1.1 can be adjusted according to the production speed. To control the flow of slag, several sets of cooling granulation rollers 4 are arranged in the lower part of the slag tank. Two cooling granulation rollers 4 form a group. N groups can be set according to needs. When the high-temperature slag comes into contact with the first group of cooling granulation rollers 4 Then it is quickly cooled to form a glassy state, and then passed through N groups of cooling granulation rollers 4 for crushing. The uniform powder formed after crushing falls into the heat exchanger 5 to complete waste heat recovery.

The specific operation process of the blast furnace slag drum quick-cooling dry treatment device is as follows:

Liquid high-temperature slag enters the blast furnace slag tank 1 at the bottom of the slag pool, flows down to the surface of the cooling granulation drum 4 through the slot 1.1 at the bottom of the blast furnace slag tank 1, and the coolant flows in the closed cooling coil 4.6, and the cooling coil 4.6 The heat transfer medium 4.10 buried in the closed space of the inner and outer cylinders exchanges heat with the slag on the surface of the outer cylinder 4.9, thereby achieving complete separation of the coolant and the slag. The cooling coil 4.6 is not in direct contact with the slag. The molten slag adheres to the surface of the outer cylinder 4.9, and the heat is transferred from the heat transfer medium 4.10 between the inner and outer cylinders to the cooling coil 4.6 buried in it. It is taken away by the coolant in the cooling coil 4.6, and the molten slag quickly cools to about 600°C to form Glassy state. The glassy slag adheres to the surface of the cooling granulating drum 4 and continues to rotate as the drum continues to rotate. When it reaches the meshing point of the two outer cylinders 4.9, it is granulated into powder under the action of the crushing teeth machined on the surface of the outer cylinder 4.9. The granulated slag enters Heat exchanger 5 recovers waste heat. The heat exchanger 5 is equipped with an oscillation mechanism to prevent powder from clogging the channel. When the device is working, slag granulation and waste heat recovery can be carried out simultaneously, realizing continuous operation of the device.

It should be noted that terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for convenience of description and are not used to To limit the implementable scope of the present invention, changes or adjustments in relative relationships shall also be regarded as the implementable scope of the present invention as long as the technical content is not substantially changed.

The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above-mentioned embodiments. All technical solutions that fall under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

A blast furnace slag drum quick-cooling dry treatment device for waste heat recovery, which is characterized by including a blast furnace slag tank (1) installed on a bracket (2), several sets of cooling granulation drums (4) and heat exchangers device(5);

The high-temperature molten slag flows downward through the adjustable-width slot (1.1) provided at the bottom of the blast furnace slag tank (1) and adheres to the outer wall of the cooling granulation drum (4). The high-temperature molten slag is cooled into glassy slag. The glassy slag The slag is sequentially squeezed and crushed by several sets of cooling granulation rollers (4) arranged in the vertical direction, and finally enters the heat exchanger (5) for waste heat recovery;

Wherein, the cooling granulation rollers (4) are grouped in pairs. Each cooling granulation roller (4) includes an outer cylinder (4.9), an inner cylinder (4.12) and a cooling coil (4.6). The outer cylinder (4.6) The closed space formed between 4.9) and the inner cylinder (4.12) is filled with heat-conducting medium (4.10), and the cooling coil (4.6) is buried in the heat-conducting medium (4.10).
A blast furnace slag drum quick-cooling dry processing device for waste heat recovery as claimed in claim 1, characterized in that: the inner layer of the blast furnace slag tank (1) is an insulating coating, and the middle is a high-temperature resistant material. The outer layer is insulated.
A blast furnace slag drum quick-cooling dry processing device for waste heat recovery as claimed in claim 1, characterized in that: the surface of the outer cylinder (4.9) is processed with crushing gear teeth, and the two outer cylinders in the same group (4.9) Intermeshing.
A blast furnace slag drum quick-cooling dry treatment device for waste heat recovery as claimed in claim 1, characterized in that: the inner cylinder (4.12) has a main shaft (4.13) axially penetrating through it, and the main shaft (4.13 ) is driven by the driving motor (3), which in turn drives the rotation of the entire cooling granulating drum (4).
A blast furnace slag roller quick-cooling dry processing device for waste heat recovery as claimed in claim 4, characterized in that: cooling liquid flows in the cooling coil (4.6), and the cooling liquid flows through the cooling liquid inflow pipe in sequence. (4.4), the inflow main pipe (4.5) and the inflow branch pipe (4.8) flow into the cooling coil (4.6), and the coolant in the cooling coil (4.6) flows out through the outflow branch pipe (4.7) and the coolant outflow pipe (4.1) in sequence; The inflow main pipe (4.5) is fixedly sleeved on the part of the main shaft (4.13) that extends out of the inner cylinder (4.12), and the coolant inflow pipe (4.4) is connected to the inflow main pipe (4.5) through the inflow rotary joint (4.3); The main shaft (4.13) is partially hollow, and the outflow branch pipe (4.7) is connected to the coolant outflow pipe (4.1) through the hollow part of the main shaft (4.13) and the outflow rotary joint (4.2); wherein, the coolant inflow pipe (4.4) , the inflow rotary joint (4.3) and the coolant outflow pipe (4.1) do not rotate with the main shaft (4.13).
A blast furnace slag drum quick-cooling dry processing device for waste heat recovery as claimed in claim 1, characterized in that: an expansion chamber (4.11) is provided on one side of the cooling granulation drum (4), and The two expansion chambers (4.11) of the set are arranged in a staggered manner. The expansion chamber (4.11) is connected to the closed space between the outer cylinder (4.9) and the inner cylinder (4.12) and is used to accommodate the expanded volume of the heat transfer medium (4.10). .
A blast furnace slag drum quick-cooling dry processing device for waste heat recovery as claimed in claim 1, characterized in that: the heat transfer medium (4.10) is tin or graphite mixed with ceramic glue.
A blast furnace slag drum quick-cooling dry processing device for waste heat recovery according to claim 1, characterized in that: the heat exchanger (5) is placed directly below the cooling granulation drum (4), The slag crushed by the cooling granulation drum (4) enters the heat exchanger (5) through the collection port, and the heat exchanger (5) is equipped with an oscillation mechanism.