Steel slag treatment and waste heat recovery system

Abstract

The utility model relates to a steel slag treatment and waste heat recovery system. The system comprises a smoke dust isolation hood; the granulation equipment group is positioned in the smoke dust isolation hood and is used for crushing and granulating the molten steel slag to obtain solid high-temperature steel slag; the circular cooler is used for carrying out heat exchange and cooling on the solid high-temperature steel slag to obtain low-temperature steel slag; the waste heat boiler is connected to the smoke dust isolation hood and the circular cooler through a smoke pipeline set and used for receiving the high-temperature smoke generated in the smoke dust isolation hood and the high-temperature smoke generated in the circular cooler through the smoke pipeline set, saturated steam and low-temperature smoke are obtained through heat exchange, and the low-temperature smoke is conveyed into the smoke dust isolation hood through the smoke pipeline set; and the first multi-pipe dust remover is connected between the circular cooler and the waste heat boiler through a flue gas pipeline group and is used for removing dust from the passing high-temperature flue gas. According to the waste heat recycling device, the waste heat of the steel slag is recycled, and the pollution of flue gas to the environment is reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of metallurgical technology in the steel industry, and in particular to a steel slag treatment and waste heat recovery system. Background Art

[0002] At present, in the metallurgical industry, there is a large amount of dust in the process of steelmaking slag treatment, which poses a great challenge to environmental protection. In addition, since the temperature of molten slag is around 1300℃, it also has considerable thermal energy recovery value. However, the existing open or semi-open hot slag treatment technology has the problem of difficult heat recovery, resulting in the lack of slag waste heat recovery process in the current slag treatment process, resulting in energy waste. Utility Model Content

[0003] In view of this, the present disclosure provides a steel slag treatment and waste heat recovery system, which can recover the waste heat of steel slag while treating the steel slag, thereby reducing energy waste.

[0004] The technical solution of the present disclosure is achieved as follows:

[0005] A slag treatment and waste heat recovery system, comprising:

[0006] Smoke and dust isolation hood;

[0007] A granulation equipment group, the granulation equipment group is located in the smoke isolation cover, and the granulation equipment group crushes and granulates the molten steel slag to obtain solid high-temperature steel slag;

[0008] A ring cooler, wherein the ring cooler cools the solid high-temperature slag by heat exchange to obtain low-temperature slag;

[0009] A waste heat boiler, wherein the waste heat boiler is connected to the smoke isolation hood and the ring cooler through a flue gas duct group, and the waste heat boiler receives the high-temperature flue gas generated in the smoke isolation hood and the high-temperature flue gas generated in the ring cooler through the flue gas duct group, and obtains saturated steam and low-temperature flue gas through heat exchange, wherein the low-temperature flue gas is transported to the smoke isolation hood through the flue gas duct group;

[0010] The first multi-tube dust collector is connected between the ring cooler and the waste heat boiler through the flue gas duct group, and the first multi-tube dust collector removes dust from the high-temperature flue gas passing therethrough.

[0011] In a possible implementation manner, the flue gas duct group includes a first flue gas duct, a second flue gas duct and a third flue gas duct, the first flue gas duct is connected to the air outlet of the smoke isolation hood, the second flue gas duct is connected to the air inlet of the waste heat boiler, the third flue gas duct is connected to the air inlet of the ring cooler, and the first flue gas duct, the second flue gas duct and the third flue gas duct are connected to each other;

[0012] The slag treatment and waste heat recovery system also includes:

[0013] A booster fan is installed at one end of the third flue gas duct close to the first flue gas duct, and when working, the booster fan transports the high-temperature flue gas in the first flue gas duct to the ring cooler.

[0014] In a possible implementation manner, the slag treatment and waste heat recovery system further includes:

[0015] A dust removal device is installed on the path of the first flue gas pipe, and the dust removal device removes dust from the high-temperature flue gas passing through the first flue gas pipe.

[0016] In one possible implementation, the dust removal device includes:

[0017] A gravity dust collector and a second multi-tube dust collector are connected in sequence, wherein the air inlet of the gravity dust collector is connected to the air outlet of the smoke isolation hood, the air inlet of the second multi-tube dust collector is connected to the air outlet of the gravity dust collector, and the air outlet of the second multi-tube dust collector is connected to the second flue gas duct and the third flue gas duct.

[0018] In a possible implementation manner, the slag treatment and waste heat recovery system further includes:

[0019] A high-pressure fan is installed at the air inlet of the smoke isolation hood, wherein the air inlet of the smoke isolation hood is connected to the air outlet of the waste heat boiler through the smoke duct group.

[0020] In a possible implementation manner, the annular cooler includes an annular cooler first section, an annular cooler second section, and an annular cooler third section, and the annular cooler first section, the annular cooler second section, and the annular cooler third section sequentially heat exchange and cool the solid high-temperature slag passing through;

[0021] The air inlet of the first section of the annular cooler and the air inlet of the second section of the annular cooler are connected to the air outlet of the waste heat boiler through the flue gas duct group;

[0022] The air inlet of a section of the ring cooler is also connected to the air outlet of the smoke isolation cover through the smoke duct group;

[0023] The air outlet of the first stage area of ​​the ring cooler and the air outlet of the second stage area of ​​the ring cooler are connected to the air inlet of the first multi-tube dust collector through the flue gas duct group.

[0024] In a possible implementation manner, the slag treatment and waste heat recovery system further includes:

[0025] A dust collector is connected to the air outlet of the second stage area of ​​the ring cooler and the air outlet of the third stage area of ​​the ring cooler, and the dust collector removes dust from the passing flue gas and discharges it.

[0026] In a possible implementation manner, the slag treatment and waste heat recovery system further includes:

[0027] A cooling fan is installed at the air inlet of the third section area of ​​the ring cooler, and the cooling fan delivers air from the external environment of the ring cooler into the third section area of ​​the ring cooler.

[0028] In one possible implementation, the granulation equipment group includes:

[0029] A slag pot dumping device, used for dumping the molten steel slag in the slag pot;

[0030] A moving bed, used for receiving the molten slag;

[0031] The crushing and granulating device is used for crushing and granulating the molten steel slag on the moving bed.

[0032] It can be seen from the above scheme that in the steel slag processing and waste heat recovery system disclosed in the present invention, the smoke dust isolation hood isolates the granulation equipment group therein, which can prevent the overflow of the smoke generated in the process of crushing and granulating the molten steel slag, and can effectively reduce the pollution of the smoke to the environment. At the same time, the high-temperature flue gas generated in the smoke dust isolation hood and the ring cooler can be used in the waste heat boiler through heat exchange to obtain saturated steam, which can be output through corresponding pipelines and can be used for heating, drying or power generation, etc., thereby realizing the recovery of the waste heat of the steel slag. The low-temperature flue gas obtained through heat exchange in the waste heat boiler can also return to the smoke dust isolation hood and the ring cooler to cool the steel slag again and obtain high-temperature flue gas again. Among them, the flue gas circulates in the waste heat boiler, the smoke dust isolation hood and the ring cooler through the flue gas duct group, which will not cause the flue gas to overflow during the circulation process, which helps to reduce the pollution of the flue gas to the environment. In addition, during the circulation of the flue gas, the large particles in the flue gas are removed by the first multi-tube dust collector, which helps to prevent the accumulation of large particles in the flue gas on the circulation path and the possible blockage of the pipelines and equipment damage in the slag treatment and waste heat recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1is a structural schematic diagram of a slag treatment and waste heat recovery system according to an exemplary embodiment;

[0034] Figure 2 It is a schematic flow diagram of a slag treatment and waste heat recovery method according to a schematic implementation.

[0035] In the accompanying drawings, the names of the components represented by the reference numerals are as follows:

[0036] 1. Smoke and dust isolation hood, 2. Granulation equipment group, 201. Slag pot dumping device, 202. Moving bed, 203. Crushing and granulation device, 3. Annular cooler, 301. Annular cooler first section, 302. Annular cooler second section, 303. Annular cooler third section, 4. Waste heat boiler, 5. First multi-tube dust collector, 6. Booster fan, 7. Dust removal device, 701. Gravity dust collector, 702. Second multi-tube dust collector, 8. High-pressure fan, 9. Cooling fan, 10. Dust collector, 11. Flue gas duct group, 1101. First flue gas duct, 1102. Second flue gas duct, 1103. Third flue gas duct. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below with reference to the accompanying drawings and examples.

[0038] Figure 1 FIG. 1 is a schematic diagram showing a slag treatment and waste heat recovery system according to an exemplary embodiment. Figure 1 As shown, the slag treatment and waste heat recovery system mainly includes a smoke isolation cover 1, a granulation equipment group 2, a ring cooler 3, a waste heat boiler 4 and a first multi-tube dust collector 5.

[0039] Among them, the granulation equipment group 2 is located in the smoke isolation hood 1, and the granulation equipment group 2 is used to crush and granulate the molten steel slag to obtain solid high-temperature steel slag. The ring cooler 3 is used to heat exchange and cool the solid high-temperature steel slag to obtain low-temperature steel slag. The waste heat boiler 4 is connected to the smoke isolation hood 1 and the ring cooler 3 through the flue gas duct group 11, and is used to receive the high-temperature flue gas generated in the smoke isolation hood 1 and the high-temperature flue gas generated in the ring cooler 3 through the flue gas duct group 11, and obtain saturated steam and low-temperature flue gas through heat exchange, wherein the low-temperature flue gas is transported to the smoke isolation hood 1 through the flue gas duct group 11. The first multi-tube dust collector 5 is connected between the ring cooler 3 and the waste heat boiler 4 through the flue gas duct group 11, and is used to remove dust from the high-temperature flue gas passing through.

[0040] Among them, the waste heat boiler 4 is an industrial equipment that uses the waste heat in the waste gas, waste materials or waste liquid generated in the industrial production process and the heat generated by the combustion of combustible substances to heat water, thereby generating steam or hot water. The working principle of the waste heat boiler 4 is to transfer the heat from the waste heat sources such as high-temperature flue gas, slag, products, etc. generated in the industrial process to water, so that the water is heated to steam or hot water. This process can improve the energy utilization efficiency of the entire industrial system and reduce thermal pollution to the environment.

[0041] The ring cooler 3, i.e., the ring flow cooler, is a cooling device used in the steel production process. Its working principle is to use cooling air to purge the material (such as the solid high-temperature steel slag mentioned in the embodiment of the present disclosure) inside the ring cooler 3, and at the same time, the cooling air duct provided inside the ring cooler 3 is used to gradually cool the material during the movement. This process not only reduces the temperature of the material, but also recovers the heat carried by the material.

[0042] Figure 1 The directions of the arrows shown indicate the directions of the airflow in the flue gas duct group 11, wherein the airflow includes high-temperature flue gas, low-temperature flue gas, air in the external environment and exhaust gas.

[0043] In the steel slag processing and waste heat recovery system of the disclosed embodiment, the smoke isolation hood 1 isolates the granulation equipment group 2 therein, which can prevent the overflow of the smoke generated in the process of crushing and granulating the molten steel slag, and can effectively reduce the pollution of the smoke to the environment. At the same time, the high-temperature smoke generated in the smoke isolation hood 1 and the ring cooler 3 can be used in the waste heat boiler 4 through heat exchange to obtain saturated steam, which can be output through corresponding pipelines and can be used for heating, drying or power generation, etc., thereby realizing the recovery of the waste heat of the steel slag. The low-temperature flue gas obtained through heat exchange in the waste heat boiler 4 can also return to the smoke isolation hood 1 and the ring cooler 3 to cool the steel slag again and obtain high-temperature flue gas again. Among them, the flue gas circulates in the waste heat boiler 4, the smoke dust isolation hood 1, and the ring cooler 3 through the flue gas duct group 11, which will not cause the flue gas to overflow during the circulation process, which helps to reduce the pollution of the flue gas to the environment. In addition, during the circulation process of the flue gas, large particles in the flue gas are removed by the first multi-tube dust collector 5, which helps to prevent the accumulation of large particles in the flue gas on the circulation path and possible pipe blockage and equipment damage in the slag treatment and waste heat recovery system.

[0044] In some cases, for example, when the heat exchange between the flue gas in the smoke isolation hood 1 and the molten slag is sufficient, so that the temperature of the high-temperature flue gas generated in the smoke isolation hood 1 reaches the requirement of the waste heat boiler 4 for heat exchange, the high-temperature flue gas generated in the smoke isolation hood 1 can enter the waste heat boiler 4 for heat exchange; in other cases, for example, when the heat exchange between the flue gas in the smoke isolation hood 1 and the molten slag is not sufficient, so that the temperature of the high-temperature flue gas generated in the smoke isolation hood 1 does not meet the requirement of the waste heat boiler 4 for heat exchange, and the high-temperature flue gas generated in the smoke isolation hood 1 needs to be further heated in the annular cooler 3 before entering the waste heat boiler 4, it is necessary to control the high-temperature flue gas generated in the smoke isolation hood 1 to enter the annular cooler 3 instead of the waste heat boiler 4. Based on this, Figure 1 As shown, in the exemplary embodiment, the flue gas duct group 11 includes a first flue gas pipe 1101, a second flue gas pipe 1102 and a third flue gas pipe 1103, the first flue gas pipe 1101 is connected to the air outlet of the smoke isolation hood 1, the second flue gas pipe 1102 is connected to the air inlet of the waste heat boiler 4, the third flue gas pipe 1103 is connected to the air inlet of the ring cooler 3, and the first flue gas pipe 1101, the second flue gas pipe 1102 and the third flue gas pipe 1103 are connected, and the slag treatment and waste heat recovery system also includes a booster fan 6, which is installed at one end of the third flue gas pipe 1103 close to the first flue gas pipe 1101, and is used to transport the high-temperature flue gas in the first flue gas pipe 1101 to the ring cooler 3 during operation. Based on the setting of the booster fan 6, when the temperature of the high-temperature flue gas generated in the smoke isolation hood 1 reaches the requirement for heat exchange of the waste heat boiler 4, the booster fan 6 does not work, and the high-temperature flue gas generated in the smoke isolation hood 1 can enter the waste heat boiler 4 for heat exchange through the first flue gas pipe 1101 and the second flue gas pipe 1102. Although part of the high-temperature flue gas may enter the annular cooler 3 through the third flue gas pipe 1103, the blocking of the booster fan 6 can make the amount of high-temperature flue gas entering the annular cooler 3 relatively small, and will not affect the cooling of the solid high-temperature steel slag in the annular cooler 3; when the temperature of the high-temperature flue gas generated in the smoke isolation hood 1 does not reach the requirement for heat exchange of the waste heat boiler 4, the booster fan 6 works, and the high-temperature flue gas generated in the smoke isolation hood 1 can enter the annular cooler 3 through the first flue gas pipe 1101 and the third flue gas pipe 1103. The high-temperature flue gas continues to exchange heat with the solid high-temperature steel slag in the annular cooler 3 to cool the solid high-temperature steel slag in the annular cooler 3 and further increase the temperature of the high-temperature flue gas.

[0045] In the exemplary embodiment, the start and stop of the booster fan 6 can be controlled by manual means. In the exemplary embodiment, the start and stop of the booster fan 6 can also be automatically controlled by means of temperature monitoring of the high-temperature flue gas in the first flue gas pipe 1101. For example, the temperature of the high-temperature flue gas in the first flue gas pipe 1101 is monitored by a temperature sensor installed in the first flue gas pipe 1101. When the temperature monitored by the temperature sensor exceeds the set temperature threshold (indicating that the temperature of the high-temperature flue gas in the smoke isolation hood 1 has reached the requirement for heat exchange of the waste heat boiler 4), the booster fan 6 is controlled to work. When the temperature monitored by the temperature sensor exceeds the set temperature threshold (indicating that the temperature of the high-temperature flue gas in the smoke isolation hood 1 has not reached the requirement for heat exchange of the waste heat boiler 4), the booster fan 6 is controlled to stop working.

[0046] In order to prevent the high temperature flue gas generated in the smoke isolation cover 1 from causing dust accumulation and blockage on the pipes and equipment in the path, such as Figure 1 As shown, in the exemplary embodiment, the slag treatment and waste heat recovery system may further include a dust removal device 7. The dust removal device 7 is installed on the path of the first flue gas pipe 1101, and is used to remove dust from the high-temperature flue gas passing through the first flue gas pipe 1101.

[0047] In the exemplary embodiment, the dust removal device 7 includes a gravity dust collector 701 and a second multi-tube dust collector 702 connected in sequence. The air inlet of the gravity dust collector 701 is connected to the air outlet of the smoke isolation cover 1, the air inlet of the second multi-tube dust collector 702 is connected to the air outlet of the gravity dust collector 701, and the air outlet of the second multi-tube dust collector 702 is connected to the second smoke pipe 1102 and the third smoke pipe 1103.

[0048] Among them, the gravity dust collector 701 is a simple mechanical dust removal device that uses the principle of gravity to separate and capture larger dust particles in the air. The working principle of the gravity dust collector 701 is to suddenly reduce the airflow velocity and change the airflow direction so that larger dust particles are separated from the airflow under the action of gravity and inertia, and then settle to the cone bottom part of the dust collector. The gravity dust collector 701 is a coarse dust removal device, which is mainly used for the preliminary separation of larger particles.

[0049] Multi-tube dust collector is a high-efficiency dry dust removal equipment, mainly used to capture dust particles in dust-laden gas. The working principle of multi-tube dust collector is mainly based on the action of centrifugal force. By increasing the airflow speed and changing the airflow direction, the dust particles are separated from the airflow due to the centrifugal force and thus captured.

[0050] It can be seen that the dust removal device 7 composed of the gravity dust collector 701 and the second multi-tube dust collector 702 can effectively remove large-particle smoke generated by a large amount of dense high-temperature smoke in the granulation equipment group 2 in the smoke isolation cover 1 during the slag granulation process, thereby reducing the dust accumulation and blockage caused by the high-temperature smoke to subsequent pipelines and equipment.

[0051] In order to increase the air intake efficiency of the low-temperature flue gas in the smoke isolation hood 1, speed up the air flow in the smoke isolation hood 1, and improve the heat exchange efficiency between the steel slag and the flue gas during the granulation process in the granulation equipment group 2, such as Figure 1 As shown, in the exemplary embodiment, the slag treatment and waste heat recovery system may further include a high-pressure fan 8. The high-pressure fan 8 is installed at the air inlet of the smoke isolation hood 1, wherein the air inlet of the smoke isolation hood 1 is connected to the air outlet of the waste heat boiler 4 through the smoke duct group 11. The low-temperature flue gas output by the waste heat boiler 4 in the smoke duct group 11 is blown into the space inside the smoke isolation hood 1 by the high-pressure fan 8, which can enhance the fluidity of the air in the smoke isolation hood 1, accelerate the heat exchange between the slag and the flue gas, and help to quickly increase the flue gas heat and reduce the slag temperature.

[0052] In order to improve the cooling effect of the ring cooler 3 on the solid high-temperature slag, Figure 1 As shown, in the exemplary embodiment, the annular cooler 3 adopts a three-stage structure. Specifically, the annular cooler 3 includes an annular cooler first stage area 301, an annular cooler second stage area 302 and an annular cooler third stage area 303, and the annular cooler first stage area 301, the annular cooler second stage area 302 and the annular cooler third stage area 303 sequentially perform heat exchange and cooling on the solid high-temperature steel slag passing through. Based on this, the temperature of the solid high-temperature steel slag is sequentially reduced in the annular cooler first stage area 301, the annular cooler second stage area 302 and the annular cooler third stage area 303.

[0053] In order to cooperate with the three-stage ring cooler 3 to improve the waste heat recovery effect, such as Figure 1 As shown, in the exemplary embodiment, the connection structure between the three-section structure and other parts of the slag treatment and waste heat recovery system of the embodiment of the present disclosure is as follows:

[0054] The air inlet of the first section 301 of the ring cooler and the air inlet of the second section 302 of the ring cooler are connected to the air outlet of the waste heat boiler 4 through the flue gas duct group 11, so that the low-temperature flue gas generated by the waste heat boiler 4 can directly enter the first section 301 of the ring cooler and the second section 302 of the ring cooler to cool the solid high-temperature slag therein;

[0055] The air inlet of the first section 301 of the annular cooler is also connected to the air outlet of the smoke isolation hood 1 through the smoke duct group 11, so that when the temperature of the high-temperature flue gas in the smoke isolation hood 1 does not meet the requirement of the waste heat boiler 4 for heat exchange, and the high-temperature flue gas generated in the smoke isolation hood 1 needs to be further heated in the annular cooler 3 before entering the waste heat boiler 4, the high-temperature flue gas in the smoke isolation hood 1 can enter the first section 301 of the annular cooler to continue to cool the solid high-temperature slag therein. In this case, the booster fan 6 in the above embodiment can be used to control the high-temperature flue gas in the smoke isolation hood 1 to flow to the first section 301 of the annular cooler;

[0056] The air outlet of the first stage area 301 of the ring cooler and the air outlet of the second stage area 302 of the ring cooler are connected to the air inlet of the first multi-tube dust collector 5 through the flue gas duct group 11, thereby helping to reduce the smoke content in the high-temperature flue gas that eventually enters the waste heat boiler 4.

[0057] The circulation of flue gas is inseparable from the consumption and replenishment of new air. In order to minimize the smoke content in the exhaust gas, in the exemplary embodiment, combined with the structure of the slag treatment and waste heat recovery system, the discharge position is set at the part that produces the least smoke, that is, the part that finally obtains low-temperature slag, and the exhaust gas needs to be further dedusted before it is discharged. Based on this, Figure 1 As shown, in the exemplary embodiment, the slag treatment and waste heat recovery system may further include a dust collector 10. The dust collector 10 is connected to the gas outlet of the second stage area 302 of the ring cooler and the gas outlet of the third stage area 303 of the ring cooler, and is used to remove dust from the passing flue gas and discharge it.

[0058] In order to accelerate the rapid cooling of the steel slag in the third section area 303 of the ring cooler, Figure 1 As shown, in the exemplary embodiment, the slag treatment and waste heat recovery system may further include a cooling fan 9. The cooling fan 9 is installed at the air inlet of the third section area 303 of the ring cooler, and is used to send air from the external environment of the ring cooler 3 into the third section area 303 of the ring cooler. The setting of the cooling fan 9 realizes further cooling of the slag in the third section area 303 of the ring cooler, ensuring that the temperature of the low-temperature slag finally discharged is within the required safe temperature range.

[0059] like Figure 1As shown, in the exemplary embodiment, the granulation equipment group 2 includes a slag pot dumping device 201, a moving bed 202 and a crushing granulation device 203. The slag pot dumping device 201 is used to dump the molten steel slag in the slag pot. The moving bed 202 is used to receive the molten steel slag. The crushing granulation device 203 is used to crush and granulate the molten steel slag on the moving bed 202. During the operation of the slag pot dumping device 201, the moving bed 202 and the crushing granulation device 203, a large amount of smoke and dust will be raised. The slag pot dumping device 201, the moving bed 202 and the crushing granulation device 203 are all placed in the smoke and dust isolation cover 1 to prevent the smoke and dust from spreading to the surrounding environment, thereby effectively reducing the pollution of the surrounding environment caused by the granulation process.

[0060] In an illustrative embodiment, the solid high-temperature steel slag obtained by the granulation equipment group is transported to the ring cooler by a steel slag conveying device. In an illustrative embodiment, the steel slag conveying device may include a steel slag slag car and an overhead crane, and the solid high-temperature steel slag is loaded in the steel slag slag car and hoisted to the ring cooler by the overhead crane. In an illustrative embodiment, the solid high-temperature steel slag can also be transported from the granulation equipment group to the ring cooler by other steel slag conveying equipment. For example, a high-temperature resistant chain conveyor can be used to transport the solid high-temperature steel slag from the granulation equipment group to the ring cooler, and the chain conveyor can be placed in a corresponding isolation cover, thereby effectively preventing the smoke and dust generated by the solid high-temperature steel slag from the granulation equipment group 2 to the ring cooler 3 from escaping into the surrounding environment.

[0061] In the exemplary embodiment, in order to increase the flow rate of the high-temperature flue gas and the low-temperature flue gas in the flue gas duct group 11, a fan can be added in the flow path of the high-temperature flue gas and the low-temperature flue gas. In addition to the high-pressure fan 8 and the booster fan 6 mentioned in the above embodiment, in the exemplary embodiment, an induced draft fan (not shown in the figure) can also be installed at the outlet of the waste heat boiler 4 in the flue gas duct group 11 to lead the low-temperature flue gas generated by the waste heat boiler 4 into the flue gas duct group 11.

[0062] Based on the steel slag treatment and waste heat recovery systems of the above-mentioned embodiments, the embodiments of the present disclosure further provide a steel slag treatment and waste heat recovery method. Figure 2 is a schematic flow diagram of a slag treatment and waste heat recovery method according to a schematic implementation, such as Figure 2 As shown, the method mainly includes the following steps.

[0063] Step 1, sending the molten steel slag to the granulation equipment group in the smoke and dust isolation cover, crushing and granulating the molten steel slag by the granulation equipment group, and in the crushing and granulation process, the molten steel slag is cooled to a solid state through heat exchange between the low-temperature flue gas received from the waste heat boiler and the molten steel slag, thereby forming solid high-temperature steel slag and high-temperature flue gas;

[0064] Step 2: The solid high-temperature slag is transported to the ring cooler through the slag conveying equipment;

[0065] Step 3: The high-temperature flue gas formed by the smoke isolation hood enters the waste heat boiler;

[0066] Step 4: In the ring cooler, heat is exchanged between the low-temperature flue gas received from the waste heat boiler and the solid high-temperature steel slag to form low-temperature steel slag and high-temperature flue gas;

[0067] Step 5: The ring cooler discharges low-temperature slag, and the high-temperature flue gas in the ring cooler enters the waste heat boiler after being dusted by the first multi-tube dust collector;

[0068] Step 6: The waste heat boiler obtains saturated steam and low-temperature flue gas by exchanging heat with the high-temperature flue gas.

[0069] The above steps are performed in the whole slag treatment process, so there is no necessary order of execution between the steps. For example, when step 1 is performed after feeding a new batch of molten slag, the work of step 4 related to the previous batch of feeding may also be performed in the annular cooler at the same time. For another example, when the high-temperature flue gas formed by the smoke isolation hood enters the waste heat boiler in step 3, the high-temperature flue gas in the annular cooler also enters the waste heat boiler in step 5.

[0070] In the application scenario of the slag treatment and waste heat recovery system and method based on the embodiment of the present disclosure, the molten slag is sent to the granulation equipment group 2 in the smoke dust isolation cover 1, and the slag pot containing the molten slag can be moved to the slag pot dumping device 201 in the granulation equipment group 2 by using slag pot lifting equipment such as an overhead crane. During this process, the smoke dust isolation cover 1 is in an open state for loading and unloading of the slag pot. In the exemplary embodiment, the smoke dust isolation cover 1 can be provided with a corresponding opening to cooperate with the loading and unloading of the slag pot and a cover door that can be opened and closed can be installed on the opening. When the cover door is opened, the slag pot can be loaded and unloaded. When the cover door is closed, the smoke dust isolation cover 1 isolates the granulation equipment group 2 therein to prevent the spillage of smoke dust during the granulation process. During the slag treatment process, the low-temperature flue gas output by the waste heat boiler 4 enters the smoke dust isolation cover 1 and performs heat exchange with the molten slag, forming solid high-temperature slag and high-temperature flue gas in the smoke dust isolation cover 1. Among them, the solid high-temperature steel slag enters the annular cooler 3 through the steel slag conveying equipment, and the high-temperature flue gas is transported to the annular cooler 3 to continue heating when the temperature does not reach the temperature requirement (for example, it does not exceed the set temperature threshold), and the high-temperature flue gas is transported to the waste heat boiler 4 when the temperature reaches the temperature requirement (for example, it exceeds the set temperature threshold). When the high-temperature flue gas is output from the smoke isolation cover 1, the larger particles of dust can be filtered out by the dust removal device 7. During the cooling process of the solid high-temperature steel slag in the annular cooler 3, the low-temperature flue gas output from the waste heat boiler 4 and the high-temperature flue gas in the smoke isolation cover 1 that does not meet the temperature requirement enter the annular cooler 3 and exchange heat with the solid high-temperature steel slag in the annular cooler 3. Among them, the annular cooler 3 includes an annular cooler first section area 301, an annular cooler second section area 302 and annular cooler third section area 303, and the solid high-temperature steel slag passes through the annular cooler first section area 301, the annular cooler second section area 302 and the annular cooler third section area 303 successively to cool and obtain low-temperature steel slag. Because the temperature of the solid high-temperature slag in the first section 301 of the ring cooler is relatively high, the low-temperature flue gas output by the waste heat boiler 4 and the high-temperature flue gas in the smoke isolation hood 1 that does not meet the temperature requirement can be input into the first section 301 of the ring cooler; the temperature of the slag in the second section 302 of the ring cooler has dropped because it has been cooled in the first section 301 of the ring cooler, so only the low-temperature flue gas output by the waste heat boiler 4 is input into the second section 302 of the ring cooler; the temperature of the slag in the third section 303 of the ring cooler has been cooled in the second section 302 of the ring cooler, so the temperature of the slag is even lower, so the cooling fan 9 is used to send the air in the external environment of the ring cooler 3 into the third section 303 of the ring cooler, so as to perform the final cooling of the slag in the third section 303 of the ring cooler. The high-temperature flue gas in the first-stage area 301 of the annular cooler finally enters the waste heat boiler 4, and the high-temperature flue gas in the second-stage area 302 of the annular cooler enters the waste heat boiler 4 at a relatively high temperature (for example, exceeding the set temperature threshold). In order to avoid damage to the waste heat boiler 4 caused by smoke, before entering the waste heat boiler 4, the high-temperature flue gas output from the first-stage area 301 of the annular cooler and the second-stage area 302 of the annular cooler are dust-removed by the first multi-tube dust collector 5.In the third section area 303 of the ring cooler, the temperature of the flue gas generated is relatively low because the temperature of the slag is relatively low. Therefore, it does not enter the waste heat boiler 4 for heat exchange, but is discharged after passing through the dust collector 10. In addition, when the temperature of the flue gas in the second section area 302 of the ring cooler is relatively low (for example, it does not exceed the set temperature threshold), it does not enter the waste heat boiler 4 for heat exchange, but is discharged after passing through the dust collector 10. The high-temperature flue gas obtains saturated steam and low-temperature flue gas through heat exchange in the waste heat boiler 4. The low-temperature flue gas enters the smoke isolation cover 1 and the ring cooler 3, and the saturated steam is output through the corresponding pipeline for heating, drying or power generation. Finally, the low-temperature slag finally obtained in the ring cooler 3 is unloaded and transported out through the corresponding equipment.

[0071] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A slag treatment and waste heat recovery system, characterized in that: include: Smoke and dust isolation hood; A granulation equipment group, the granulation equipment group is located in the smoke isolation cover, and the granulation equipment group crushes and granulates the molten steel slag to obtain solid high-temperature steel slag; A ring cooler, wherein the ring cooler cools the solid high-temperature slag by heat exchange to obtain low-temperature slag; A waste heat boiler, wherein the waste heat boiler is connected to the smoke isolation hood and the ring cooler through a flue gas duct group, and the waste heat boiler receives the high-temperature flue gas generated in the smoke isolation hood and the high-temperature flue gas generated in the ring cooler through the flue gas duct group, and obtains saturated steam and low-temperature flue gas through heat exchange, wherein the low-temperature flue gas is transported to the smoke isolation hood through the flue gas duct group; The first multi-tube dust collector is connected between the ring cooler and the waste heat boiler through the flue gas duct group, and the first multi-tube dust collector removes dust from the high-temperature flue gas passing therethrough.

2. The slag treatment and waste heat recovery system according to claim 1, characterized in that: The flue gas duct group includes a first flue gas duct, a second flue gas duct and a third flue gas duct, wherein the first flue gas duct is connected to the air outlet of the smoke isolation cover, the second flue gas duct is connected to the air inlet of the waste heat boiler, the third flue gas duct is connected to the air inlet of the ring cooler, and the first flue gas duct, the second flue gas duct and the third flue gas duct are connected to each other; The slag treatment and waste heat recovery system also includes: A booster fan is installed at one end of the third flue gas duct close to the first flue gas duct, and when working, the booster fan transports the high-temperature flue gas in the first flue gas duct to the ring cooler.

3. The slag treatment and waste heat recovery system according to claim 2, characterized in that: Also includes: A dust removal device is installed on the path of the first flue gas pipe, and the dust removal device removes dust from the high-temperature flue gas passing through the first flue gas pipe.

4. The slag treatment and waste heat recovery system according to claim 3, characterized in that: The dust removal device comprises: A gravity dust collector and a second multi-tube dust collector are connected in sequence, wherein the air inlet of the gravity dust collector is connected to the air outlet of the smoke isolation hood, the air inlet of the second multi-tube dust collector is connected to the air outlet of the gravity dust collector, and the air outlet of the second multi-tube dust collector is connected to the second flue gas duct and the third flue gas duct.

5. The slag treatment and waste heat recovery system according to claim 1, characterized in that: Also includes: A high-pressure fan is installed at the air inlet of the smoke isolation hood, wherein the air inlet of the smoke isolation hood is connected to the air outlet of the waste heat boiler through the smoke duct group.

6. The slag treatment and waste heat recovery system according to claim 1, characterized in that: The annular cooler comprises an annular cooler first section, an annular cooler second section and an annular cooler third section, and the annular cooler first section, the annular cooler second section and the annular cooler third section sequentially exchange heat and cool the solid high-temperature slag passing through; The air inlet of the first section of the annular cooler and the air inlet of the second section of the annular cooler are connected to the air outlet of the waste heat boiler through the flue gas duct group; The air inlet of a section of the ring cooler is also connected to the air outlet of the smoke isolation cover through the smoke duct group; The air outlet of the first stage area of ​​the ring cooler and the air outlet of the second stage area of ​​the ring cooler are connected to the air inlet of the first multi-tube dust collector through the flue gas duct group.

7. The slag treatment and waste heat recovery system according to claim 6, characterized in that: Also includes: A dust collector is connected to the air outlet of the second stage area of ​​the ring cooler and the air outlet of the third stage area of ​​the ring cooler, and the dust collector removes dust from the passing flue gas and discharges it.

8. The slag treatment and waste heat recovery system according to claim 6, characterized in that: Also includes: A cooling fan is installed at the air inlet of the third section area of ​​the ring cooler, and the cooling fan delivers air from the external environment of the ring cooler into the third section area of ​​the ring cooler.

9. The slag treatment and waste heat recovery system according to claim 1, characterized in that: The granulation equipment group comprises: A slag pot dumping device, used for dumping the molten steel slag in the slag pot; A moving bed, used for receiving the molten slag; The crushing and granulating device is used for crushing and granulating the molten steel slag on the moving bed.

Images