A molten steel slag sensible heat recovery device based on radiation heat exchange and convection heat exchange

Abstract

The utility model relates to sensible heat recovery equipment field, concretely relates to a kind of molten steel slag sensible heat recovery device based on radiation heat transfer and convection heat transfer, including tank heat exchanger, vertical heat exchange tower and waste heat boiler, tank heat exchanger is used to carry out radiation heat transfer with water and high-temperature molten state steel slag, and high-temperature molten state steel slag is cooled into broken granular medium-temperature solid steel slag, while generating saturated steam;Vertical heat exchange tower is used to receive medium-temperature solid steel slag, and pass into low-temperature exhaust gas discharged by waste heat boiler, and medium-temperature solid steel slag is cooled to target temperature by counterflow heat exchange, while low-temperature exhaust gas is heated to high-temperature exhaust gas;Waste heat boiler uses saturated steam and high-temperature exhaust gas to produce superheated steam, and provide low-temperature exhaust gas.The embodiment of the utility model does not contact water in the process of cooling broken high-temperature molten state steel slag, avoids the problem that a large amount of dust-containing steam is generated by water quenching method, high-temperature steel slag and medium-temperature steel slag are treated in stages, improve heat energy recovery efficiency, while effectively saving water resources.

Description

Technical Field

[0001] This utility model relates to the field of sensible heat recovery equipment, specifically to a sensible heat recovery device for molten steel slag based on radiation heat transfer and convection heat transfer. Background Technology

[0002] Existing steel slag treatment processes do not recover the enormous sensible heat resources of high-temperature molten steel slag. Furthermore, commonly used hot pouring, pool simmering, drum method, and pressurized or atmospheric pressure roller hot crushing processes consume large amounts of water resources. In particular, the roller hot crushing process generates a large amount of dust-laden water vapor by spraying a large amount of water onto the high-temperature molten steel slag for cooling, which greatly increases the dust removal workload of the system, resulting in high energy consumption and increased production costs for enterprises. Utility Model Content

[0003] The purpose of this invention is to provide a sensible heat recovery device for molten steel slag based on radiation heat transfer and convection heat transfer, so as to solve the problems of traditional high-temperature molten steel slag treatment methods consuming a large amount of water resources, generating a large amount of dust, and being energy-intensive and environmentally unfriendly.

[0004] To solve the above-mentioned technical problems, this utility model specifically provides the following technical solution:

[0005] A sensible heat recovery device for molten steel slag based on radiative and convective heat exchange includes: a tank heat exchanger for radiative heat exchange between water and high-temperature molten steel slag, cooling the high-temperature molten steel slag into broken granular medium-temperature solid steel slag, while generating saturated steam; a vertical heat exchange tower connected to the slag outlet of the tank heat exchanger for receiving the medium-temperature solid steel slag and introducing low-temperature waste gas discharged from a waste heat boiler, cooling the medium-temperature solid steel slag to a target temperature through countercurrent heat exchange, while heating the low-temperature waste gas into high-temperature waste gas; and a waste heat boiler, whose saturated steam inlet is connected to the saturated steam outlet of the tank heat exchanger, and whose high-temperature waste gas inlet is connected to the high-temperature waste gas outlet of the vertical heat exchange tower, for using the saturated steam and the high-temperature waste gas to produce superheated steam, and whose low-temperature waste gas outlet is connected to the low-temperature waste gas inlet of the vertical heat exchange tower to provide the low-temperature waste gas.

[0006] Furthermore, there are at least three tank heat exchangers, and multiple tank heat exchangers are configured to operate in staggered shifts to achieve continuous material and energy supply to the vertical heat exchange tower and the waste heat boiler.

[0007] Furthermore, the tank heat exchanger includes: a processing tank, which is a rotatable horizontal cylindrical structure for containing the high-temperature molten steel slag; a horizontal rotary table for supporting and driving the processing tank to rotate; a radiant heat exchanger fixedly disposed inside the processing tank for absorbing the radiant heat energy of the steel slag to produce the saturated steam; and crushing teeth fixedly disposed inside the processing tank for applying mechanical impact force to the steel slag during the solidification process to crush it into particles when the processing tank rotates.

[0008] Furthermore, cooling water channels are provided in the wall interlayer of the processing tank and inside the crushing teeth.

[0009] Furthermore, a high-temperature reflective layer is provided on the upper part of the inner wall of the processing tank.

[0010] Furthermore, the interior of the vertical heat exchange tower is alternately equipped with positive cone guide plates and inverted cone guide plates from top to bottom to guide the medium-temperature solid steel slag to form a diffusion-convergence spiral falling path.

[0011] Furthermore, both the positive cone guide plate and the inverted cone guide plate are provided with circumferentially distributed elongated holes.

[0012] Furthermore, it also includes a high-temperature waste gas conveying system, which connects the high-temperature waste gas outlet of the vertical heat exchange tower to the hot air inlet of the waste heat boiler. A cyclone dust collector and a metal cartridge dust collector are sequentially installed in the gas pipeline of the high-temperature waste gas conveying system.

[0013] Furthermore, it also includes a low-temperature exhaust gas conveying system, which connects the low-temperature exhaust gas outlet of the waste heat boiler to the low-temperature exhaust gas inlet of the vertical heat exchange tower. The gas pipeline of the low-temperature exhaust gas conveying system is equipped with a circulating fan, a throttle valve, and a cold air valve. The throttle valve is used to regulate the airflow, and the cold air valve is used to introduce external cold air.

[0014] Furthermore, it also includes a medium-temperature steel slag conveying system, which connects the slag outlet of the tank heat exchanger with the slag inlet of the vertical heat exchange tower. The medium-temperature steel slag conveying system includes a chain conveyor and a bucket elevator arranged in sequence.

[0015] Compared with the prior art, this application has the following advantages:

[0016] A sensible heat recovery device for molten steel slag based on radiation and convection heat transfer is proposed. The high-temperature steel slag does not come into contact with water during the cooling and crushing process, avoiding the problem of generating a large amount of dust-containing steam in water quenching. The high-temperature steel slag and medium-temperature steel slag are processed in stages, which improves the heat recovery efficiency and system adaptability. While crushing steel slag with low energy consumption, the device effectively recovers the sensible heat of the steel slag, provides high-quality steam for enterprises, brings additional economic benefits, and saves water resources. Attached Figure Description

[0017] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0018] Figure 1 This is a system diagram of an embodiment of the present utility model;

[0019] Figure 2 This describes the slag inlet conditions of the tank heat exchanger in this embodiment of the present invention.

[0020] Figure 3 The heat exchange conditions of the tank heat exchanger in this embodiment of the utility model;

[0021] Figure 4 This describes the slag discharge condition of the tank heat exchanger in an embodiment of this utility model.

[0022] Figure 5 This is a structural diagram of a vertical heat exchange tower according to an embodiment of the present utility model;

[0023] The labels in the diagram represent the following:

[0024] 1-Tank heat exchanger; 11-Processing tank; 12-Feeding port; 13-Door cover; 14-Horizontal rotary table; 15-Radiant heat exchanger; 16-Crushing teeth; 2-Vertical heat exchange tower; 21-Tower body; 22-Positive cone guide plate; 23-Inverted cone guide plate; 24-Elongated hole; 25-Hollow column; 26-Chain plate conveyor; 27-Bucket elevator; 3-Waste heat boiler; 31-Saturated steam conveying pipe; 32-Throttle valve; 33-Low temperature air duct; 34-Circulating fan; 35-Cold air valve; 36-High temperature air duct; 37-Cyclone dust collector; 38-Metal cartridge dust collector. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] To address the aforementioned issues, this embodiment proposes a sensible heat recovery device and method for molten steel slag based on radiation and convection heat transfer.

[0027] (Explanation of sensible heat recovery device and sensible heat recovery method)

[0028] refer to Figure 1 The sensible heat recovery device includes a tank heat exchanger 1, a vertical heat exchange tower 2, and a waste heat boiler 3. The tank heat exchanger 1 is used for water cooling heat exchange of high-temperature molten steel slag (above 1300℃) and forcing it to cool into broken granular medium-temperature solid steel slag (around 800℃), while generating saturated steam. The vertical heat exchange tower 2 guides low-temperature waste gas and medium-temperature solid steel slag to convect and exchange heat inside it, cooling the medium-temperature solid steel slag to the target temperature, while generating high-temperature waste gas. The high-temperature waste gas and saturated steam are introduced into the waste heat boiler 3 to produce superheated steam, realizing the dry recovery of sensible heat of steel slag.

[0029] The target temperature is slightly higher than the temperature of the ambient water input into the waste heat boiler 3.

[0030] The sensible heat recovery method includes the following steps:

[0031] Step 1: High-temperature molten steel slag (above 1300℃) is fed into tank heat exchanger 1. Tank heat exchanger 1 performs crushing and water cooling heat exchange, cooling the high-temperature molten steel slag into small pieces of medium-temperature solid steel slag (around 800℃), while generating saturated steam.

[0032] Step 2: The medium-temperature solid steel slag is fed into the vertical heat exchange tower 2 and allowed to flow naturally from top to bottom. At the same time, the low-temperature waste gas discharged from the waste heat boiler 3 is fed into the vertical heat exchange tower 2 and allowed to flow naturally from bottom to top. The medium-temperature solid steel slag and the low-temperature waste gas exchange heat through convection. The medium-temperature solid steel slag is cooled to the target temperature, and the low-temperature waste gas is heated to high-temperature waste gas.

[0033] Step 3: The saturated steam generated in Step 1 and the high-temperature waste gas generated in Step 2 are introduced into the waste heat boiler 3 to produce superheated steam.

[0034] Preferably, there are at least three tank heat exchangers 1 in the sensible heat recovery device and sensible heat recovery method. Multiple tank heat exchangers 1 operate in staggered shifts to ensure that saturated steam can be stably delivered to the waste heat boiler 3, while medium-temperature solid steel slag can be stably delivered to the vertical heat exchange tower 2.

[0035] (Explanation of tank heat exchanger 1)

[0036] refer to Figures 2 to 4 The tank heat exchanger 1 includes: a processing tank 11, a horizontal rotary table 14, a radiant heat exchanger 15, and a crushing tooth 16.

[0037] The processing tank 11 is a rotatable horizontal cylindrical structure used to contain high-temperature molten steel slag. The horizontal rotary table 14 is used to support and drive the processing tank 11 to rotate around its own axis. The peripheral wall of the processing tank 11 is provided with a slag passage port, and an openable cover 13 is installed on the slag passage port. The cover 13 is opened when feeding and discharging.

[0038] When steel slag is fed into the processing tank 11, the slag passage is located at the top of the processing tank 11; when the steel slag is processed inside the processing tank 11, the slag passage swings back and forth at the top of the processing tank 11 as the processing tank 11 reciprocates and rotates, and the slag passage can be closed or not closed; when discharging slag, the slag passage is located at the bottom of the processing tank 11, thereby discharging the steel slag inside the processing tank 11.

[0039] Preferably, a cooling water channel (not shown) is provided inside the interlayer of the wall of the treatment tank 11. The cooling water channel is used to circulate cooling water, which absorbs the heat of the steel slag through heat conduction on the one hand, and protects the treatment tank 11 itself from being damaged by high temperature on the other hand. A high temperature reflective layer (not shown) is provided on the upper part of the inner wall of the treatment tank 11. The high temperature reflective layer is used to reflect the heat radiation of the steel slag to the radiation heat exchanger 15.

[0040] The radiant heat exchanger 15 and the crushing tooth 16 are fixed inside the processing tank 11 by a bracket and do not rotate synchronously with the processing tank 11.

[0041] The radiant heat exchanger 15 is used to absorb the heat radiation generated by the high-temperature molten steel slag inside the treatment tank 11. One end of the radiant heat exchanger 15 is higher than the other end. Room temperature water is input into the radiant heat exchanger 15 from the lower end. After absorbing heat, the room temperature water forms saturated steam and leaves from the higher end of the radiant heat exchanger 15.

[0042] The crushing tooth 16 can withstand the impact of steel slag. When the processing tank 11 performs reciprocating rotational motion, the crushing tooth 16 generates relative motion with the high-temperature molten steel slag inside the processing tank 11, and applies mechanical impact force to the high-temperature molten steel slag, thereby causing the high-temperature molten steel slag to solidify into medium-temperature solid steel slag and naturally forming small particles.

[0043] Furthermore, the crusher tooth 16 is provided with a cooling water channel inside, and the support connecting the frame and the crusher tooth 16 is provided with a cooling water channel communicating with the crusher tooth 16. This allows the cooling water to circulate inside the crusher tooth 16 to reduce the temperature of the crusher tooth 16 and ensure that the crusher tooth 16 can work normally under high temperature and impact conditions.

[0044] The horizontal rotary table 14 includes two sets of load-bearing wheels, which are respectively arranged on both sides of the processing tank 11. Each set of load-bearing wheels includes at least two coaxial load-bearing wheels, so that the processing tank 11 can be stably supported by the load-bearing wheels.

[0045] The horizontal rotary table 14 also includes a motor (not shown) that drives the load-bearing wheels or the processing tank 11 to rotate, so that the processing tank 11 can rotate and reciprocate.

[0046] (Explanation of Vertical Heat Exchanger 2)

[0047] refer to Figure 5 The vertical heat exchange tower 2 includes a tower body 21, with a steel slag inlet and a high-temperature exhaust gas outlet at the top and a steel slag outlet and a low-temperature exhaust gas inlet at the bottom.

[0048] The interior of tower body 21 is equipped with:

[0049] The alternating conical guide plates 22 and inverted conical guide plates 23 arranged from top to bottom allow the medium-temperature solid steel slag to flow sequentially through them under gravity, forming a spiral-shaped, layer-by-layer downward path of diffusion and convergence, thereby extending the heat exchange path of the medium-temperature solid steel slag.

[0050] Both the positive cone guide plate 22 and the inverted cone guide plate 23 are provided with circumferentially distributed elongated holes 24, thereby forming a multi-stage turbulent airflow field for the low-temperature exhaust gas flowing from bottom to top, which enhances gas-solid turbulent mixing and heat exchange.

[0051] The conical guide plate 22 is fixed by a hollow column 25 erected coaxially inside the tower body 21. Water is circulated inside the hollow column 25 for cooling. The inverted conical guide plate 23 is rigidly connected to the inner wall of the tower body 21, thereby enhancing the thermal shock resistance of the tower body 21.

[0052] (Explanation regarding waste heat boiler 3)

[0053] Working principle of waste heat boiler 3:

[0054] The waste heat boiler 3 uses the high-temperature waste gas generated by the vertical heat exchange tower 2 and the tank heat exchanger 1 as the main heat source to heat the boiler working fluid water to generate steam and superheat it to produce superheated steam.

[0055] The waste heat boiler 3 also utilizes the saturated steam generated by the tank heat exchanger 1, and introduces it into the superheated section of the waste heat boiler 3 for further heating, thereby generating superheated steam.

[0056] (Supplementary explanation regarding sensible heat recovery devices and methods)

[0057] Further reference Figure 1 The sensible heat recovery device for molten steel slag based on radiation and convection heat transfer also includes other components to facilitate the implementation of the sensible heat recovery method, such as:

[0058] Component 1: A conveying system connecting the outlet of the tank heat exchanger 1 and the inlet of the vertical heat exchange tower 2, including: a chain conveyor 26 and a bucket elevator 27.

[0059] Among them, the chain plate conveyor 26 is used to receive the medium-temperature solid steel slag of about 800°C poured out from each tank heat exchanger 1 and transport it to the feed port of the bucket elevator 27. The bucket elevator 27 is used to lift the medium-temperature solid steel slag to the feed port at the top of the vertical heat exchange tower 2.

[0060] Component 2: A low-temperature waste gas conveying system connecting the air outlet of the waste heat boiler 3 and the air inlet of the vertical heat exchange tower 2, including: a throttle valve 32, a low-temperature air duct 33, a circulating fan 34, and a cold air valve 35.

[0061] The waste heat boiler 3's air outlet, throttle valve 32, low-temperature air duct 33, circulating fan 34, and vertical heat exchange tower 2's air inlet are connected in sequence. The circulating fan 34 is used to draw low-temperature waste gas from the inside of the waste heat boiler 3 through the low-temperature air duct 33 and discharge it to the air inlet of the vertical heat exchange tower 2. The throttle valve 32 is used to control the fluctuation of air pressure and airflow inside the low-temperature air duct 33. The cold air valve 35 is connected to the low-temperature air duct 33 and the outside through a tee. The cold air valve 35 is used to actively open when the temperature of the low-temperature waste gas inside the low-temperature air duct 33 is too high, so that the circulating fan 34 can draw low-temperature air from the outside into the interior of the vertical heat exchange tower 2.

[0062] This design effectively controls the pressure, flow rate, and temperature of the gas entering the vertical heat exchanger 2, thereby making the temperature of the steel slag output from the vertical heat exchanger 2 more stable.

[0063] Component 3: A high-temperature exhaust gas conveying system connecting the air outlet of the vertical heat exchange tower 2 and the air inlet of the waste heat boiler 3, including: a high-temperature air duct 36, a cyclone dust collector 37, and a metal cartridge dust collector 38.

[0064] The vertical heat exchange tower 2 is connected in sequence to the air outlet, high-temperature air duct 36, cyclone dust collector 37, metal filter cartridge dust collector 38 and waste heat boiler 3. The high-temperature exhaust gas discharged from the vertical heat exchange tower 2 is discharged to the waste heat boiler 3 after two dust removal processes.

[0065] Component 4: Saturated steam delivery pipe 31 connecting the saturated steam outlet of tank heat exchanger 1 and the saturated steam inlet of waste heat boiler 3, wherein the saturated steam moves by its own pressure.

[0066] Component 5, cooling water delivery system (not shown in the figure) connecting the cooling water inlet of the tank heat exchanger 1, includes: a water pump and a water storage tank.

[0067] The cooling water inlet, water pump, and water storage tank are connected in sequence. The water tank is used to store water, and the water pump is used to pump water into the cooling water inlet.

[0068] The core advantages and innovations of this embodiment are:

[0069] Dry processing throughout: The high-temperature molten steel slag does not come into contact with water during the cooling and crushing process, avoiding the problem of generating a large amount of dust-containing steam in the water quenching method, and significantly reducing the investment and operating costs of environmental protection equipment.

[0070] Segmented processing and efficient recovery: High-temperature molten steel slag (high-grade heat energy) and medium-temperature solid steel slag (medium and low-grade heat energy) are processed in stages, which improves the heat recovery efficiency and system adaptability.

[0071] Continuous and stable energy output: By combining the intermittent coordinated operation of multiple tank heat exchangers 1 with the continuous operation of vertical heat exchange tower 2 and waste heat boiler 3, the conversion from intermittent slag supply to continuous and stable production of high-temperature superheated steam is realized, meeting the demand of subsequent systems such as power generation for a stable heat source.

[0072] Energy saving and economic benefits: While crushing steel slag with low energy consumption, the sensible heat of the steel slag is effectively recovered to provide high-quality steam for enterprises, bringing additional economic benefits and saving water resources.

[0073] The above embodiments are merely exemplary embodiments of this utility model and are not intended to limit this utility model. The scope of protection of this utility model is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this utility model within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered as falling within the scope of protection of this utility model.

Claims

1. A device for recovering sensible heat from molten steel slag based on radiative and convective heat transfer, characterized in that, A tank heat exchanger (1) is used to radiate heat exchange between water and high-temperature molten steel slag, and to cool the high-temperature molten steel slag into broken granular medium-temperature solid steel slag, while generating saturated steam. Vertical heat exchange tower (2) is connected to the slag passage of the tank heat exchanger (1) to receive the medium-temperature solid steel slag and to pass the low-temperature waste gas discharged from the waste heat boiler (3). The medium-temperature solid steel slag is cooled to the target temperature through countercurrent heat exchange, while the low-temperature waste gas is heated to high-temperature waste gas. The waste heat boiler (3) has its saturated steam inlet connected to the saturated steam outlet of the tank heat exchanger (1) and its high-temperature waste gas inlet connected to the high-temperature waste gas outlet of the vertical heat exchange tower (2) for producing superheated steam using the saturated steam and the high-temperature waste gas. The low-temperature waste gas outlet of the waste heat boiler (3) is connected to the low-temperature waste gas inlet of the vertical heat exchange tower (2) to provide the low-temperature waste gas.

2. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that, There are at least three tank heat exchangers (1), and multiple tank heat exchangers (1) are configured to operate in staggered shifts to achieve continuous material and energy supply to the vertical heat exchange tower (2) and the waste heat boiler (3).

3. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that, The tank heat exchanger (1) includes: The processing tank (11) is a rotatable horizontal cylindrical structure used to contain the high-temperature molten steel slag; A horizontal rotary table (14) is used to support and drive the processing tank (11) to rotate; A radiant heat exchanger (15) is fixedly installed inside the processing tank (11) to absorb the radiant heat energy of the steel slag to produce the saturated steam. The crushing tooth (16) is fixedly installed inside the processing tank (11) and is used to apply mechanical impact force to the steel slag during the solidification process to crush it into particles when the processing tank (11) rotates.

4. The sensible heat recovery device for molten steel slag according to claim 3, characterized in that, Cooling water channels are provided in the wall interlayer of the processing tank (11) and inside the crushing tooth (16).

5. The sensible heat recovery device for molten steel slag according to claim 3, characterized in that, A high-temperature reflective layer is provided on the upper part of the inner wall of the processing tank (11).

6. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that, The interior of the vertical heat exchange tower (2) is alternately equipped with positive cone guide plates (22) and inverted cone guide plates (23) from top to bottom, which are used to guide the medium-temperature solid steel slag to form a diffusion-convergence spiral falling path.

7. The sensible heat recovery device for molten steel slag according to claim 6, characterized in that, Both the positive cone guide plate (22) and the inverted cone guide plate (23) are provided with circumferentially distributed elongated holes (24).

8. The sensible heat recovery device for molten steel slag according to claim 6, characterized in that, It also includes a high-temperature exhaust gas conveying system, which connects the high-temperature exhaust gas outlet of the vertical heat exchange tower (2) to the hot air inlet of the waste heat boiler (3). A cyclone dust collector (37) and a metal cartridge dust collector (38) are sequentially installed in the gas pipeline of the high-temperature exhaust gas conveying system.

9. The sensible heat recovery device for molten steel slag according to claim 6, characterized in that, It also includes a low-temperature exhaust gas conveying system, which connects the low-temperature exhaust gas outlet of the waste heat boiler (3) to the low-temperature exhaust gas inlet of the vertical heat exchange tower (2). The gas pipeline of the low-temperature exhaust gas conveying system is equipped with a circulating fan (34), a throttle valve (32) and a cold air valve (35). The throttle valve (32) is used to regulate the airflow, and the cold air valve (35) is used to introduce external cold air.

10. The sensible heat recovery device for molten steel slag according to claim 1, characterized in that, It also includes a medium-temperature steel slag conveying system, which connects the slag passage port of the tank heat exchanger (1) with the slag inlet of the vertical heat exchange tower (2). The medium-temperature steel slag conveying system includes a chain plate conveyor (26) and a bucket elevator (27) arranged in sequence.

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