A two-stage hot slag locking-feeding device and its operation method

Abstract

A two-stage hot slag locking-feeding device and an operation method thereof, comprising a first and a second feeding section, wherein the upper end of the first feeding section is connected to a first slag locking valve, the first feeding section is composed of a first upper pressure zone, a first slag stopping zone and a first inflation zone from top to bottom, the lower part of the first inflation zone is connected to the upper end of the second feeding section through a second slag locking valve, the second feeding section is composed of a second upper pressure zone, a second slag stopping zone and a second inflation zone from top to bottom, and the lower part of the second inflation zone is connected to a third slag locking valve; hot steel slag is transported to the top of the first feeding section, the pressure in the first feeding section is adjusted to be the same as that in a transfer slag locking tank by inert gas, and the hot steel slag enters the first feeding section; the pressure in the second feeding section is adjusted to be the same as that in the first feeding section, and the hot steel slag enters the second feeding section; the pressure in the second feeding section is adjusted to be the same as that in a quenching heat recovery furnace, and the hot steel slag enters the quenching heat recovery furnace; the present invention ensures that the operating pressure in the quenching heat recovery furnace is maintained during the hot steel slag feeding process.

Description

Technical Field

[0001] The invention relates to the technical field of heat recovery of high-temperature hot steel slag, and in particular to a two-stage hot slag locking-feeding device and an operation method thereof. Background Art

[0002] The steel industry is a pillar industry of the national economy and a resource- and energy-intensive industry. Its energy consumption accounts for 4-5% of the world's total energy consumption. However, the energy utilization rate of steel enterprises is only about 50%, and there is still a lot of surplus energy that has not been fully utilized. Since steel enterprises mainly consume thermal energy, most of the surplus energy exists in the form of thermal energy. The high-temperature waste heat resources of steel plants include product waste heat, waste heat from waste gas, and slag waste heat. Among them, product waste heat and waste heat from waste gas have been effectively recovered, but there is no mature recovery technology for industrial application of waste heat from slag (especially high-temperature hot steel slag). Although steel slag contains a large amount of sensible heat, it is difficult to recover waste heat due to intermittent slag discharge and current treatment processes.

[0003] At present, slag trucks are basically used to transport hot slag to designated locations for water slag flushing to recover the slag. This method not only wastes a lot of water resources, making it difficult to recycle water resources, but also wastes the high-quality waste heat resources contained therein, and the heat recovery efficiency is very low. In order to improve the heat recovery efficiency of sensible heat in hot slag and save water resources, the application team proposed a zero-drainage smelting slag quenching heat recovery device and process (patent application number: 202211145384.7). In this patent, in order to improve the grade and utilization value of water vapor generated by the quenching heat recovery furnace, the operating pressure of the quenching heat recovery furnace is set to 0.27MPa or even higher. However, hot slag cannot be transported through pipelines, and is generally transported by slag trucks or slag tanks. How to maintain the operating pressure in the quenching heat recovery furnace during the hot slag feeding process is the key to improving the heat recovery rate. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a two-stage hot slag locking-feeding device and an operating method thereof, so as to ensure that the operating pressure in the quenching heat recovery furnace is maintained during the hot slag feeding process, and to provide technical support for improving the heat recovery utilization rate of the hot slag.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A two-stage hot slag locking-feeding device comprises a first feeding section 1 and a second feeding section 2. The upper end of the first feeding section 1 is vertically connected with a first slag locking valve 11. The first feeding section 1 is divided into a first upper pressure zone 16, a first slag stopping zone 17 and a first inflation zone 18 from top to bottom. The first inflation zone 18 is vertically connected to the upper end of the second feeding section 2 through a second slag locking valve 21 below. The second feeding section 2 is divided into a second upper pressure zone 26, a second slag stopping zone 27 and a second inflation zone 28 from top to bottom. The second inflation zone 28 is vertically connected to a third slag locking valve 3 below.

[0007] A first inert gas outlet 13 is arranged on the outer side of the first upper pressure zone 16, a first inert gas inlet 12 is arranged on the outer side of the first inflation zone 18, a first air film buffer zone 15 is arranged on the outer side of the first slag stopping zone 17, and a second inert gas inlet 14 is arranged on the outer side of the first air film buffer zone 15; similarly, a second inert gas outlet 23 is arranged on the outer side of the second upper pressure zone 26, a third inert gas inlet 22 is arranged on the outer side of the second inflation zone 28, a second air film buffer zone 25 is arranged on the outer side of the second slag stopping zone, and a fourth inert gas inlet 24 is arranged on the outer side of the second air film buffer zone 25.

[0008] The first slag stopping area 17 and the second slag stopping area 27 are provided with first micropores 52 on their inner walls. The diameter of the first micropores 52 is 3-5 mm, and the opening rate is 20%.

[0009] The first inflation area 18 and the second inflation area 28 include an inflation buffer area 41 and an inflation hole plate 42. The inflation hole plate 42 is provided with second micropores 43. The diameter of the second micropores 43 is 2-3 mm, and the opening rate is 30%.

[0010] The first slag lock valve 11, the second slag lock valve 21 and the third slag lock valve 3 are all automatically controlled.

[0011] The main structures of the first feeding section 1 and the second feeding section 2 are cylinders or cuboids.

[0012] The inert gas introduced into the first inert gas inlet 12 , the second inert gas inlet 14 , the third inert gas inlet 22 and the fourth inert gas inlet 24 is nitrogen or carbon dioxide.

[0013] An operating method of a two-stage hot slag locking and feeding device comprises the following steps:

[0014] In the first step, the hot slag is transferred to the top of the first feeding section 1 through the transfer slag lock tank 6, and at the same time, the first regulating valve 71 is opened to send the inert gas in the first inert gas storage tank 7 from the first inert gas inlet 12 to the first charging area 18, and the pressure in the first charging section 1 is adjusted to be equal to the pressure in the transfer slag lock tank 6, and the first slag lock valve 11 is opened to send the hot slag from the transfer slag lock tank 6 to the first charging section 1, and at the same time, the second regulating valve 72 is opened to send the inert gas in the first inert gas storage tank 7 from the second inert gas inlet 12 to the first charging area 18. The hot slag is fed into the first air film buffer zone 15 through the body inlet 14, and then forms an air film in the inner wall 51 through the first micropores 52 on the inner wall 51 of the first slag stopping zone 17. At the same time, the first inert gas outlet 13 is opened, and the pressure in the first feeding section 1 is adjusted to be equal to the pressure in the transfer slag lock tank 6, so that the hot slag stays in the first slag stopping zone 17. The inert gas from the first inert gas outlet 13 first passes through the first dust collector 9 to remove dust, and then is compressed by the first compressor 91 and fed into the first inert gas storage tank 7 for recycling;

[0015] The second step is to close the first slag lock valve 11, then open the third regulating valve 81 to send the inert gas in the second inert gas storage tank 8 into the second charging zone 18 from the third inert gas inlet 22, and open the second slag lock valve 21 when the pressure in the second feeding section 2 is adjusted to be equal to the pressure in the first feeding section 1, and send the hot slag from the first feeding section 1 to the second feeding section 2. At the same time, open the fourth regulating valve 82 to send the inert gas in the second inert gas storage tank 8 into the second air film buffer zone 25 from the fourth inert gas inlet 24, and then pass the second slag stop valve 81 to the second inert gas storage tank 8. The first micropores 52 on the inner wall 51 of the zone 27 form a gas film inside the inner wall 51, and at the same time, the second inert gas outlet 23 is opened, and the pressure in the second feeding section 2 is adjusted to be equal to the pressure in the first feeding section, so that the hot slag stays in the second slag stopping zone 27, and at the same time, the first regulating valve 71, the second regulating valve 72 and the first inert gas outlet 13 are closed, and the inert gas coming out of the second inert gas outlet 23 first passes through the second dust collector 10 to remove dust, and then is compressed by the second compressor 101 and sent to the second inert gas storage tank 8 for recycling;

[0016] The third step is to close the second slag lock valve 21, and then adjust the third regulating valve 81 and the fourth regulating valve 82 to make the pressure in the second feeding section 2 the same as the operating pressure in the quenching heat recovery furnace, and then open the third slag lock valve 3, and close the third regulating valve 81 and the fourth regulating valve 82 at the same time to allow the hot slag to enter the quenching heat recovery furnace, and finally close the third slag lock valve 3, and close the third regulating valve 81, the fourth regulating valve 82 and the second inert gas outlet 23 at the same time to complete one feeding.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention realizes solid feeding of the quenching heat recovery furnace under medium pressure operation conditions, providing a basis for improving the heat recovery rate of hot slag;

[0019] 2. The present invention adjusts the pressure of the first feeding section 1 and the second feeding section 2 by inert gas, which can prevent the hot slag from being oxidized, reduce the heat loss during the feeding process, and improve the heat recovery rate;

[0020] 3. The present invention adjusts the pressure in the feeding section by inert gas, forms an air film on the inner wall of the slag stopping zone, reduces the wall hanging phenomenon of hot slag during the feeding process, and forms an air cushion in the inflation zone, reduces the impact of hot slag on the slag lock valve during the feeding process, reduces the wear of the slag lock valve, and increases its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the two-stage hot slag locking-feeding device of the present invention.

[0022] Figure 2 It is a schematic diagram of the structure of the first slag stopping area 17 and the second slag stopping area 27.

[0023] Figure 3 Schematic diagram of the structure of the first inflation area 18 and the second inflation area 28.

[0024] Figure 4 It is an operation flow chart of a two-stage hot slag locking and charging device of a hot slag quenching heat recovery furnace. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0026] like Figure 1 As shown, a two-stage hot slag locking-feeding device comprises a first feeding section 1 and a second feeding section 2. The upper end of the first feeding section 1 is vertically connected with a first slag locking valve 11. The first feeding section 1 is divided into a first upper pressure zone 16, a first slag stopping zone 17 and a first inflation zone 18 from top to bottom. The first inflation zone 18 is vertically connected to the upper end of the second feeding section 2 through a second slag locking valve 21 below. The second feeding section 2 is divided into a second upper pressure zone 26, a second slag stopping zone 27 and a second inflation zone 28 from top to bottom. The second inflation zone 28 is vertically connected to the third slag locking valve 3 below.

[0027] A first inert gas outlet 13 is arranged on the outer side of the first upper pressure zone 16, a first inert gas inlet 12 is arranged on the outer side of the first inflation zone 18, a first air film buffer zone 15 is arranged on the outer side of the first slag stopping zone 17, and a second inert gas inlet 14 is arranged on the outer side of the first air film buffer zone 15; similarly, a second inert gas outlet 23 is arranged on the outer side of the second upper pressure zone 26, a third inert gas inlet 22 is arranged on the outer side of the second inflation zone 28, a second air film buffer zone 25 is arranged on the outer side of the second slag stopping zone, and a fourth inert gas inlet 24 is arranged on the outer side of the second air film buffer zone 25.

[0028] like Figure 2 As shown, first micropores 52 are provided on the inner walls 51 of the first slag stopping area 17 and the second slag stopping area 27. The diameter of the first micropores 52 is 3-5 mm, and the opening rate is 20%.

[0029] like Figure 3 As shown, the first inflation area 18 and the second inflation area 28 both include an inflation buffer area 41 and an inflation hole plate 42. The inflation hole plate 42 is provided with second micropores 43. The diameter of the second micropores 43 is 2-3 mm, and the opening rate is 30%.

[0030] The first slag lock valve 11, the second slag lock valve 21 and the third slag lock valve 3 are all automatically controlled.

[0031] The main structures of the first feeding section 1 and the second feeding section 2 are cylinders or cuboids.

[0032] The inert gas introduced into the first inert gas inlet 12 , the second inert gas inlet 14 , the third inert gas inlet 22 and the fourth inert gas inlet 24 is nitrogen or carbon dioxide.

[0033] like Figure 4 As shown, a method for operating a two-stage hot slag locking and feeding device comprises the following steps:

[0034] In the first step, the hot steel slag at 1400-1600°C is transferred to the top of the first feeding section 1 through the transfer slag lock tank 6 with a loading amount of 1 ton / time, and at the same time, the first regulating valve 71 is opened to send the inert gas in the first inert gas storage tank 7 from the first inert gas inlet 12 to the first charging area 18, and the pressure in the first feeding section 1 is adjusted to 0.6-1.0MPa (equal to the pressure in the transfer slag lock tank 6), and the first slag lock valve 11 is opened to send the hot steel slag from the transfer slag lock tank 6 to the first feeding section 1, and at the same time, the second regulating valve 72 is opened to send the inert gas in the first inert gas storage tank 7 from the second inert gas inlet 12 to the first charging area 18. The inert gas inlet 14 is fed into the first air film buffer zone 15, and then a layer of air film is formed in the inner wall 51 through the first micropores 52 on the inner wall 51 of the first slag stopping zone 17. At the same time, the first inert gas outlet 13 is opened, and the pressure in the first feeding section 1 is adjusted to maintain at 0.6-1.0 MPa (equal to the pressure in the transfer slag lock tank 6), so that the hot slag stays in the first slag stopping zone 17. The inert gas coming out of the first inert gas outlet 13 first passes through the first dust collector 9 to remove 99.9% of the dust, and then is compressed to 1.5 MPa by the first compressor 91 and fed into the first inert gas storage tank 7 for recycling;

[0035] The second step is to close the first slag lock valve 11, then open the third regulating valve 81 to send the inert gas in the second inert gas storage tank 8 from the third inert gas inlet 22 to the second charging zone 18, and when the pressure in the second feeding section 2 is adjusted to 0.6-1.0 MPa (equal to the pressure in the first feeding section 1), open the second slag lock valve 21 to send the hot slag from the first feeding section 1 to the second feeding section 2, and at the same time open the fourth regulating valve 82 to send the inert gas in the second inert gas storage tank 8 from the fourth inert gas inlet 24 to the second gas film buffer zone 25, and then pass through the inner wall 51 of the second slag stopping zone 27. The first micropore 52 on the inner wall 51 forms an air film, and at the same time, the second inert gas outlet 23 is opened, and the pressure in the second feeding section 2 is adjusted to maintain at 0.6-1.0 MPa (equal to the pressure in the first feeding section 1), so that the hot slag stays in the second slag stopping area 27, and at the same time, the first regulating valve 71, the second regulating valve 72 and the first inert gas outlet 13 are closed, and the inert gas coming out of the second inert gas outlet 23 first passes through the second dust collector 10 to remove 99.9% of the dust, and then is compressed to 5-6 MPa by the second compressor 101 and sent to the second inert gas storage tank 8 for recycling;

[0036] The third step is to close the second slag lock valve 21, and then adjust the third regulating valve 81 and the fourth regulating valve 82 to make the pressure in the second feeding section 2 be 3-4 MPa (the same as the operating pressure in the quenching heat recovery furnace), and then open the third slag lock valve 3, and close the third regulating valve 81 and the fourth regulating valve 82 at the same time to allow the hot slag to enter the quenching heat recovery furnace, and finally close the third slag lock valve 3, and close the third regulating valve 81, the fourth regulating valve 82 and the second inert gas outlet 23 at the same time to complete one feeding.

[0037] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field shall fall within the protection scope of the claims of the present invention.

Claims

1. A two-stage hot slag locking and feeding device, characterized in that: The invention comprises a first feeding section (1) and a second feeding section (2), wherein the upper end of the first feeding section (1) is vertically connected with a first slag locking valve (11), the first feeding section (1) is divided into a first upper pressure zone (16), a first slag stopping zone (17) and a first gas charging zone (18) in sequence from top to bottom, the lower part of the first gas charging zone (18) is vertically connected to the upper end of the second feeding section (2) through a second slag locking valve (21), the lower part of the second feeding section (2) is divided into a second upper pressure zone (26), a second slag stopping zone (27) and a second gas charging zone (28), the lower part of the second gas charging zone (28) is vertically connected to a third slag locking valve (3); A first inert gas outlet (13) is arranged on the outer side of the first upper pressure zone (16), a first inert gas inlet (12) is arranged on the outer side of the first inflation zone (18), a first air film buffer zone (15) is arranged on the outer side of the first slag stopping zone (17), and a second inert gas inlet (14) is arranged on the outer side of the first air film buffer zone (15); similarly, a second inert gas outlet (23) is arranged on the outer side of the second upper pressure zone (26), a third inert gas inlet (22) is arranged on the outer side of the second inflation zone (28), a second air film buffer zone (25) is arranged on the outer side of the second slag stopping zone, and a fourth inert gas inlet (24) is arranged on the outer side of the second air film buffer zone (25).

2. The device according to claim 1, characterized in that: First micropores (52) are provided on the inner walls (51) of the first slag stopping zone (17) and the second slag stopping zone (27). The diameter of the first micropores (52) is 3-5 mm, and the opening rate is 20%.

3. The device according to claim 1, characterized in that: The first inflation zone (18) and the second inflation zone (28) comprise an inflation buffer zone (41) and an inflation hole plate (42). The inflation hole plate (42) is provided with a second micro hole (43). The diameter of the second micro hole (43) is 2 to 3 mm, and the opening rate is 30%.

4. The device according to claim 1, characterized in that: The first slag lock valve (11), the second slag lock valve (21) and the third slag lock valve (3) are all automatically controlled.

5. The device according to claim 1, characterized in that: The main structures of the first feeding section (1) and the second feeding section (2) are cylindrical or rectangular.

6. The device according to claim 1, characterized in that: The inert gas introduced into the first inert gas inlet (12), the second inert gas inlet (14), the third inert gas inlet (22) and the fourth inert gas inlet (24) is nitrogen or carbon dioxide.

7. The method for operating the device according to any one of claims 1 to 6, characterized in that: The following steps are involved: The first step is to transfer the hot slag to the top of the first feeding section (1) through the transfer slag lock tank (6), and at the same time open the first regulating valve (71) to send the inert gas in the first inert gas storage tank (7) from the first inert gas inlet (12) to the first charging zone (18), and adjust the pressure in the first charging section (1) to be equal to the pressure in the transfer slag lock tank (6), then open the first slag lock valve (11), and send the hot slag from the transfer slag lock tank (6) into the first charging section (1), and at the same time open the second regulating valve (72) to send the inert gas in the first inert gas storage tank (7) from the second inert gas inlet (12). The inlet (14) is fed into the first air film buffer zone (15), and then a layer of air film is formed inside the inner wall (51) of the first slag stopping zone (17) through the first micropore (52) on the inner wall (51), and at the same time, the first inert gas outlet (13) is opened, and the pressure in the first feeding section (1) is adjusted to maintain the pressure equal to the pressure in the transfer slag lock tank (6), so that the hot slag stays in the first slag stopping zone (17). The inert gas coming out of the first inert gas outlet (13) first passes through the first dust collector (9) to remove dust, and then is compressed by the first compressor (91) and fed into the first inert gas storage tank (7) for recycling; The second step is to close the first slag lock valve (11), then open the third regulating valve (81) to feed the inert gas in the second inert gas storage tank (8) into the second gas charging zone (28) through the third inert gas inlet (22), and when the pressure in the second feeding section (2) is adjusted to be equal to the pressure in the first feeding section (1), open the second slag lock valve (21) to feed the hot slag from the first feeding section (1) into the second feeding section (2), and at the same time open the fourth regulating valve (82) to feed the inert gas in the second inert gas storage tank (8) into the second gas film buffer zone (25) through the fourth inert gas inlet (24), and then pass the second slag stop valve (83) to the second gas film buffer zone (25). The first micropores (52) on the inner wall (51) of the zone (27) form a gas film inside the inner wall (51), and at the same time the second inert gas outlet (23) is opened, and the pressure inside the second feeding section (2) is adjusted to be equal to the pressure inside the first feeding section, so that the hot slag stays in the second slag stopping zone (27), and at the same time the first regulating valve (71), the second regulating valve (72) and the first inert gas outlet (13) are closed, and the inert gas coming out of the second inert gas outlet (23) first passes through the second dust collector (10) to remove dust, and then is compressed by the second compressor (101) and sent to the second inert gas storage tank (8) for recycling; The third step is to close the second slag lock valve (21), and then adjust the third regulating valve (81) and the fourth regulating valve (82) so that the pressure in the second feeding section (2) is the same as the operating pressure in the quenching heat recovery furnace, and then open the third slag lock valve (3), and at the same time close the third regulating valve (81) and the fourth regulating valve (82) to allow the hot slag to enter the quenching heat recovery furnace, and finally close the third slag lock valve (3), and at the same time close the third regulating valve (81), the fourth regulating valve (82) and the second inert gas outlet (23) to complete one feeding.

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