Steel scrap preheating device, electric furnace steel scrap feeding system and electric furnace steel scrap preheating method

Abstract

The invention relates to a waste steel preheating device which comprises a rotary charging barrel and a rotary driving mechanism used for driving the rotary charging barrel to do rotary motion, a plurality of inner material grooves are formed in the inner wall of the rotary charging barrel, all the inner material grooves extend from one end of the rotary charging barrel to the other end of the rotary charging barrel, and all the inner material grooves are sequentially arranged in the circumferential direction of the rotary charging barrel. In addition, the invention further relates to an electric furnace steel scrap feeding system adopting the steel scrap preheating device and an electric furnace steel scrap preheating method implemented based on the steel scrap preheating device. The rotary charging barrel is adopted as a waste steel preheating container, waste steel can flow into the adjacent inner material groove from one inner material groove in the rotary motion process of the rotary charging barrel, the waste steel can be turned over by promoting the waste steel to flow between the different inner material grooves, the upper layer and the lower layer of a waste steel material layer can generate sufficient heat exchange with smoke, and the waste steel preheating effect is improved. And meanwhile, the material layer can be looser through the actions such as rolling and turning over of the scrap steel, the heat exchange efficiency of the scrap steel material layer is greatly improved, and finally the preheating temperature of the scrap steel is greatly increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric furnace production, and particularly relates to a scrap steel preheating device, an electric furnace scrap steel feeding system adopting the scrap steel preheating device, and an electric furnace scrap steel preheating method based on the scrap steel preheating device. BACKGROUND

[0002] Although the electric arc furnace steelmaking technology has made great progress, the overall smelting comprehensive energy consumption is still high. Since the flue gas temperature of the electric arc furnace can reach about 1300℃, the heat taken away with the flue gas sensible heat accounts for as much as 13% to 20% of the total input heat. At present, most enterprises use electric furnace flue gas to preheat scrap steel. In theory, for every 100℃ increase in the preheating temperature of scrap steel, 20 kWh of electric energy can be saved per ton of steel. In addition to saving energy and reducing consumption, scrap steel preheating can also shorten the smelting cycle and improve productivity.

[0003] At present, the relatively advanced and stable scrap steel preheating technology in the world is mainly the Consteel type electric arc furnace scrap steel preheating method. The Consteel type electric arc furnace scrap steel preheating is to continuously preheat the furnace charge in the horizontal conveying process by using the high-temperature waste flue gas generated by the furnace while continuously charging. The actual temperature of the scrap steel before entering the furnace reaches 100℃ to 200℃, and the preheated waste gas enters the waste heat recovery system through the combustion chamber, realizing continuous preheating, continuous charging and continuous melting of scrap steel, and improving productivity. Although the Consteel type electric arc furnace scrap steel preheating feeding system rarely has the risk of blocking and clamping steel, since the high-temperature flue gas passes through the surface of the scrap steel layer, the temperature of the scrap steel at the bottom is basically not preheated, resulting in a low average temperature of the scrap steel and a high outlet temperature of the flue gas, and the flue gas waste heat utilization efficiency is low. SUMMARY

[0004] The present application relates to a scrap steel preheating device, an electric furnace scrap steel feeding system adopting the scrap steel preheating device, and an electric furnace scrap steel preheating method based on the scrap steel preheating device, which can at least solve some defects of the prior art.

[0005] The present application relates to a scrap steel preheating device, which comprises a rotary cylinder and a rotary driving mechanism for driving the rotary cylinder to rotate, and a plurality of inner material grooves are formed on the inner wall of the rotary cylinder, each of the inner material grooves extends from one end of the rotary cylinder to the other end, and each of the inner material grooves is arranged along the circumference of the rotary cylinder.

[0006] As one of the embodiments, the planes where the two inner material groove walls of each group of adjacent inner material grooves belonging to two inner material grooves intersect.

[0007] As one of the embodiments, the two inner material groove walls of each group of adjacent inner material grooves belonging to two inner material grooves intersect.

[0008] As one of the embodiments, the two inner material groove walls of each group of adjacent and two inner material grooves intersect to form a dihedral angle in the range of 80° to 150°.

[0009] As one of the embodiments, one end of the rotary cylinder is connected with a feeding section and is rotatable relative to the feeding section, the feeding section comprises a feeding groove and a feeding hood covering the feeding groove.

[0010] The other end of the rotary cylinder is connected with a discharging section and is rotatable relative to the discharging section, the discharging section comprises a discharging groove and a discharging hood covering the discharging groove.

[0011] As one of the embodiments, the scrap steel preheating device further comprises a synchronous frame, the lower part of the synchronous frame is fixedly connected with the feeding groove and the discharging groove respectively, and the upper part of the synchronous frame is fixedly connected with the feeding hood and the discharging hood respectively.

[0012] As one of the embodiments, the bottom of the feeding groove, the bottom end of the cylinder cavity of the rotary cylinder and the bottom of the discharging groove are arranged in sequence from high to low.

[0013] As one of the embodiments, the rotary cylinder is further provided with an axial limiting mechanism for limiting the axial displacement thereof.

[0014] The present application also relates to an electric furnace scrap steel feeding system comprising a scrap steel feeding section and a scrap steel preheating device as described above, and the rotary cylinder is connected with the scrap steel feeding section and the electric furnace scrap steel inlet respectively.

[0015] The present application also relates to an electric furnace scrap steel preheating method based on the scrap steel preheating device as described above, and the method comprises the following steps.

[0016] The scrap steel to be preheated is sent into the rotary cylinder, and the electric furnace flue gas is introduced into the rotary cylinder.

[0017] The rotary cylinder is driven to rotate, and the electric furnace flue gas exchanges heat with the scrap steel to preheat the scrap steel.

[0018] The present application has at least the following beneficial effects:

[0019] The present application uses a rotary cylinder as a scrap steel preheating container, and in the process of rotating the rotary cylinder, the scrap steel can flow from one inner material groove to the adjacent inner material groove, and by promoting the flow of scrap steel between different inner material grooves, the scrap steel can be turned over, so that the upper and lower layers of the scrap steel material layer can exchange heat with the flue gas sufficiently, and at the same time, the rolling and turning over of the scrap steel can make the material layer more loose, greatly improving the heat exchange efficiency of the scrap steel material layer, and finally the preheating temperature of the scrap steel is greatly improved. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the electric furnace scrap steel feeding system provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the scrap steel preheating device provided in an embodiment of the present invention;

[0023] Figure 3 A cross-sectional view of the scrap steel preheating device provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram showing the relative positions of the feed chute, inner feed chute, and discharge chute.

[0025] Figure 5 This is a schematic diagram of scrap steel turning over in a rotary drum;

[0026] Figure 6 This is a schematic diagram of the scrap steel feeding device provided in an embodiment of the present invention;

[0027] Figure 7 This is a cross-sectional view of the scrap steel feeding device. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: As Figure 2 and Figure 3 This invention provides a scrap steel preheating device 1, including a rotary material cylinder 111 and a rotary drive mechanism for driving the rotary material cylinder 111 to rotate. A plurality of inner material grooves 118 are formed on the inner wall of the rotary material cylinder 111, and each inner material groove 118 extends from one end of the rotary material cylinder 111 to the other end. The inner material grooves 118 are arranged sequentially along the circumference of the rotary material cylinder 111.

[0030] Preferably, the outer wall of the rotary cylinder 111 is cylindrical to facilitate rotary motion. For the rotary drive, a transmission unit is preferably provided on the outer wall of the rotary cylinder 111, which is connected to the rotary drive mechanism; this includes, but is not limited to, a pin-gear transmission method. The transmission unit correspondingly uses pins 114, which are evenly arranged around the circumference of the rotary cylinder 111. The rotary drive mechanism correspondingly includes a pin gear 113 and a rotary drive unit 112. The pin gear 113 meshes with the pins 114. The rotary drive unit 112 includes, but is not limited to, a motor, and its output end is connected to the pin gear 113. Obviously, gear drives, chain drives, belt drives, etc., can all be used as alternatives to the pin-gear transmission method, and will not be listed here.

[0031] Optionally, such as Figure 2 A rotary guide mechanism can be provided on one or both sides of the rotary drive point (the position corresponding to the transmission part / rotary drive mechanism) to guide the rotary motion of the rotary cylinder 111 and ensure the stability and reliability of the rotary motion. In one embodiment, the rotary guide mechanism includes multiple support wheels 117, which are arranged sequentially at intervals along the circumference of the rotary cylinder. Each support wheel 117 rolls in contact with the outer wall of the rotary cylinder (the axial direction of the support wheel 117 is parallel to the axial direction of the rotary cylinder). In this scheme, the support wheels 117 not only guide the rotary cylinder 111 in rotation, but also reliably support and limit the rotation of the rotary cylinder 111. Preferably, rotary guide mechanisms are provided on both sides of the rotary drive point, which can ensure the stability of the position of the rotary cylinder 111 and improve the stability of the rotary motion.

[0032] Preferably, the rotary drum 111 is further equipped with an axial limiting mechanism to restrict its axial displacement, limiting the rotary drum 111 to only rotate, thus ensuring the stability and reliability of the rotary drum 111's movement. In one embodiment, such as Figure 2 The axial limiting mechanism includes an annular limiting plate 115 and at least one set of limiting wheels. The annular limiting plate 115 is coaxially disposed on the outer wall of the rotary cylinder 111. Each set of limiting wheels includes two limiting wheels 116 arranged on both sides of the annular limiting plate 115 along the axial direction of the rotary cylinder 111. The two limiting wheels 116 are in rolling contact with the annular limiting plate 115 respectively (the axis of the limiting wheel 116 is perpendicular to the axis of the rotary cylinder 111). This axial limiting method can ensure the axial limiting effect without affecting the rotational movement of the rotary cylinder 111.

[0033] Preferably, the axis of the rotary feeder 111 is parallel to the horizontal plane; in addition, both ends of the rotary feeder 111 are open to facilitate the entry and exit of scrap steel 4 and the entry and exit of electric furnace flue gas.

[0034] The inner material groove 118 is arranged along the length direction (i.e. axial direction) of the rotary cylinder 111; the length direction of the inner material groove 118 is preferably parallel to the axial direction of the rotary cylinder 111, but the length direction of the inner material groove 118 can also form an angle greater than 0° and less than 90° with the axial direction of the rotary cylinder 111.

[0035] It is a feasible scheme that there are only two inner material grooves 118 in the rotary cylinder 111, but it is more favorable for the preheating of the scrap steel 4 to design the number of the inner material grooves 118 to be three or more. Figure 3 In the embodiment, a scheme in which three inner material grooves 118 are formed in the rotary cylinder 111 is shown; it is a feasible scheme that the number of the inner material grooves 118 is more than three, but it is not shown.

[0036] As Figure 5 During the rotation of the rotary cylinder 111, the scrap steel 4 can flow from one inner material groove 118 to the adjacent inner material groove 118, and the turning of the scrap steel 4 can be realized by promoting the flow of the scrap steel 4 between different inner material grooves 118, so that the upper and lower layers of the scrap steel layer can fully exchange heat with the flue gas, and the turning of the scrap steel 4 and other actions can make the material layer more loose, greatly improving the heat exchange efficiency of the scrap steel material layer, and finally greatly improving the preheating temperature of the scrap steel 4.

[0037] Each inner material groove 118 has two opposite groove walls. In one embodiment, the groove width defined between the two groove walls is consistent from the groove bottom to the groove opening; in another embodiment, the groove width defined between the two groove walls gradually increases from the groove bottom to the groove opening. In addition, it is also a feasible scheme that the inner material groove 118 adopts a stepped groove, in which each groove section of the inner material groove 118 can adopt the above two groove width forms. If the groove width defined between the two groove walls gradually decreases from the groove bottom to the groove opening, it may increase the difficulty of the scrap steel 4 escaping from the inner material groove 118, so it is appropriate not to adopt this structure.

[0038] In one embodiment, the planes where the two inner material groove walls 1181 of each group of adjacent inner material grooves 118 belonging to two inner material grooves 118 intersect, specifically:

[0039] The two inner material groove walls 1181 of each group of adjacent inner material grooves 118 belonging to two inner material grooves 118 directly intersect;

[0040] Or, the two inner material groove walls 1181 of each group of adjacent inner material grooves 118 belonging to two inner material grooves 118 extend to intersect, and in this case, the two inner material groove walls 1181 are preferably extended from the groove bottom to the groove opening to intersect, i.e. the intersection is located on the side of the groove opening away from the groove bottom.

[0041] Optionally, the dihedral angle between the planes in which the two inner material groove walls 1181 of each group of adjacent inner material groove walls belonging to two adjacent inner material grooves 118 intersect is in the range of 80°-150°, facilitating the transfer and flow of scrap steel 4 between the two adjacent inner material grooves 118.

[0042] Preferably, as Figure 3 , the direct intersection of the two inner material groove walls 1181 of each group of adjacent inner material groove walls belonging to two adjacent inner material grooves 118 facilitates the transfer and flow of scrap steel 4 between the two adjacent inner material grooves 118.

[0043] As Figure 5 , during use, as the rotary drum 111 rotates, the scrap steel 4 rotates with the inner material grooves 118. Since the inner material grooves 118 have a certain height, the scrap steel 4 does not immediately tumble when it first starts to rotate. When it rotates to a certain angle, the scrap steel 4 begins to fall into the adjacent inner material groove 118 on the opposite side of the rotary drum 111 under the action of gravity. Since the inner material grooves 118 are separated by groove walls, the scrap steel 4 slides along the intersecting inner material groove walls 1181 into the other inner material groove 118. Because the upper layer of scrap steel 4 does not have a cumulative effect, the upper layer of scrap steel 4 tumbles first. As the angle of the rotary drum 111 increases, the scrap steel 4 gradually falls from the upper layer to the lower layer in turn. The intersecting inner material groove walls 1181 also assist in turning the scrap steel layer over. When the rotary drum 111 rotates to a certain angle, the upper and lower layers of the scrap steel layer are completely reversed, and the lower layer of scrap steel 4 at a lower temperature is roasted and exchanges heat with the flue gas.

[0044] Further optimization of the above-described scrap steel preheating device 1, as Figure 2 , one end of the rotary drum 111 is connected to a feeding section, and the rotary drum 111 is rotatable relative to the feeding section. The feeding section includes a feeding groove 121 and a feeding flue hood 122 covering the feeding groove 121. Preferably, the feeding groove 121 and the feeding flue hood 122 are detachably fixedly connected, and a sealing element can be provided at the connection between the two to improve the sealing performance. The rotary drum 111 can rotate relative to the feeding groove 121 and the feeding flue hood 122. Therefore, the rotary drum 111 and the feeding groove 121 are not fixedly connected, and the rotary drum 111 and the feeding flue hood 122 are not fixedly connected, so that the feeding end of the rotary drum 111 and the discharge end of the feeding groove 121, and the feeding end of the rotary drum 111 and the flue gas inlet end of the feeding flue hood 122 can be gap-connected, to ensure that the rotary drum 111 can rotate freely, while reducing the escape of flue gas and dust from the rotary drum 111 and the feeding groove 121, and the rotary drum 111 and the feeding flue hood 122. Optionally, as Figure 2, the outlet end of the feeding groove 121 is downwardly protruded to form a lower flange, and the lower flange is in clearance fit with the inner wall of the rotary cylinder 111, which can facilitate the transfer of the scrap steel 4 from the feeding groove 121 to the rotary cylinder 111; the outer wall of the feeding hood 122 is in clearance fit with the inner wall of the rotary cylinder 111.

[0045] Further, as Figure 2 , the rotary cylinder 111 and the feeding groove 121 are sealed at the joint, and the rotary cylinder 111 and the feeding hood 122 are sealed at the joint, which includes but is not limited to using the annular sealing element 14 to seal the two joints at the same time, and the annular sealing element 14 can be installed on the feeding end of the rotary cylinder 111 and rotate with the rotary cylinder 111, or can be installed on the feeding groove 121 and the feeding hood 122, and both of the two ways can realize dynamic sealing through the annular sealing element 14.

[0046] Further optimize the above scrap steel preheating device 1, such as Figure 2 , the other end of the rotary cylinder 111 is connected with a discharging section and is rotatable relative to the discharging section, and the discharging section includes a discharging groove 131 and a discharging hood 132 covering the discharging groove 131. Wherein, the discharging groove 131 and the discharging hood 132 are preferably detachably fixed, and a sealing element can be arranged at the connection between the two to improve the sealing performance. The rotary cylinder 111 can rotate relative to the discharging groove 131 and the discharging hood 132, therefore, the rotary cylinder 111 and the discharging groove 131 are not fixedly connected, and the rotary cylinder 111 and the discharging hood 132 are not fixedly connected, so that the outlet end of the rotary cylinder 111 and the inlet end of the discharging groove 131, and the outlet end of the rotary cylinder 111 and the outlet end of the feeding hood 122 are in clearance fit, so as to ensure that the rotary cylinder 111 can rotate freely, and to reduce the escape of flue gas and dust from the rotary cylinder 111 and the discharging groove 131, and the rotary cylinder 111 and the discharging hood 132, and the entry of external air, etc. Optionally, as Figure 2 , the inlet end of the discharging groove 131 is upwardly protruded to form an upper flange, and the upper flange is in clearance fit with the outer wall of the rotary cylinder 111, which can facilitate the transfer of the scrap steel 4 from the rotary cylinder 111 to the discharging groove 131; the inner wall of the discharging hood 132 is in clearance fit with the outer wall of the rotary cylinder 111.

[0047] Further, as Figure 2At the joint between the rotary cylinder 111 and the discharge hood 132, a sealing treatment is performed, including but not limited to sealing the joint by a sealing plate 15, which is preferably installed on the inner wall of the discharge hood 132 and abuts against the discharge end of the rotary cylinder 111, maintaining contact with the rotary cylinder 111 during rotation of the rotary cylinder 111 to achieve dynamic sealing; when the sealing plate 15 is made of a resilient sealing material with a certain elasticity, the dynamic contact effect with the rotary cylinder 111 is better.

[0048] For the joint between the rotary cylinder 111 and the discharge chute 131, a sealing member can also be provided at the joint, which is preferably provided on the outer surface of the upper flange and in contact with the outer wall of the rotary cylinder 111, so as to avoid interference with the scrap steel 4 in the discharge chute 131; in another alternative embodiment, as shown in Figure 2 The sealing at this position can be achieved by means of the corresponding side support wheel 117, and this structure also facilitates the installation of the support wheel 117, for example, the axle of the support wheel 117 is installed on the upper flange. Similarly, the joint between the rotary cylinder 111 and the discharge hood 132 can also be sealed from the outside by means of the support wheel 117.

[0049] In one embodiment, as shown in Figure 2 The scrap steel preheating device 1 further comprises a synchronous frame 16, the lower part of the synchronous frame 16 is fixedly connected with the feeding chute 121 and the discharge chute 131 respectively, and the upper part of the synchronous frame 16 is fixedly connected with the feeding hood 122 and the discharge hood 132 respectively; the feeding chute 121 is connected with a vibrator or a vibrator chute. Based on this structure, the feeding chute 121 and the discharge chute 131 are connected as a whole structure by the synchronous frame 16, and the rotary cylinder 111 is rotatably installed on the whole structure, so that the feeding chute 121, the rotary cylinder 111 and the discharge chute 131 resonate at the same frequency with the vibrator, and the scrap steel 4 is continuously conveyed to the electric furnace 3.

[0050] Among them, the above-mentioned rotary drive unit 112, limit wheel 116, support wheel 117 and other components can be installed on the synchronous frame 16, therefore, the above-mentioned synchronous frame 16 can greatly facilitate the installation of related facilities of the rotary cylinder 111, and accordingly simplify the structure of the scrap steel preheating device 1.

[0051] Further preferably, the synchronous frame 16 adopts a ring-shaped cylinder frame, which surrounds the rotary cylinder 111, which not only facilitates the connection of the synchronous frame 16 with the feeding groove 121, the discharging groove 131, the feeding smoke hood 122, the discharging smoke hood 132 and the like, but also facilitates the sealing of the connection between the synchronous frame 16 and the feeding groove 121, the discharging groove 131, the feeding smoke hood 122, the discharging smoke hood 132 and the like, which greatly improves the sealing performance of the scrap steel preheating device 1, and can avoid the poor dynamic sealing effect to cause the smoke and dust to escape and the outside air to enter and the like.

[0052] Preferably, as Figure 4 , the groove bottom of the feeding groove 121, the bottom end of the cylinder cavity of the rotary cylinder 111 and the groove bottom of the discharging groove 131 are arranged in sequence, which facilitates the flow of the scrap steel 4 and facilitates the turnover and loosening of the scrap steel 4; optionally, the height difference between the groove bottom of the feeding groove 121 and the bottom end of the cylinder cavity of the rotary cylinder 111 is in the range of 600-700 mm, and the height difference between the bottom end of the cylinder cavity of the rotary cylinder 111 and the groove bottom of the discharging groove 131 is in the range of 600-700 mm.

[0053] In addition, preferably, as Figure 3 and Figure 4 , the groove width of the feeding groove 121 is smaller than the groove width of the inner material groove 118, and optionally, an interfacing cross section is arranged at the discharging end of the feeding groove 121, and the groove width of the interfacing cross section gradually increases from the feeding groove 121 to the rotary cylinder 111, so as to facilitate the better connection of the feeding groove 121 with the inner material groove 118. Similarly, the groove width of the discharging groove 131 is greater than the groove width of the inner material groove 118, and optionally, an interfacing cross section is arranged at the feeding end of the discharging groove 131, and the groove width of the interfacing cross section gradually increases from the rotary cylinder 111 to the discharging groove 131, so as to facilitate the better connection of the discharging groove 131 with the inner material groove 118.

[0054] Embodiment two: as Figure 1 , the embodiment of the present application provides an electric furnace scrap steel feeding system, which comprises a scrap steel feeding section 2 and the scrap steel preheating device 1 provided in the above embodiment one, and the rotary cylinder 111 is connected with the scrap steel feeding section 2 and the electric furnace scrap steel inlet, respectively.

[0055] Optionally, the scrap steel feeding section 2 is connected with the scrap steel preheating device 1 through a middle vibrator, and as described in the above embodiment one, the feeding groove 121 is connected with the vibrator groove of the middle vibrator. In the scrap steel feeding section 2, the scrap steel 4 is added into the feeding section groove through a feeding device such as a magnetic disc crane, a scrap steel grabber or a chain plate machine, and then is vibrated by the vibrator at the tail of the scrap steel feeding section 2 to move forward, and is added into the electric furnace 3 through the middle vibrator and the scrap steel preheating device 1 for smelting.

[0056] The discharge hood 132 is connected with the flue gas outlet of the electric furnace 3, and the flue gas of the electric furnace enters the rotary cylinder 111 from the discharge hood 132 and is discharged from the feeding hood 122.

[0057] Optionally, the scrap steel preheating device 1 can be connected with the scrap steel inlet of the electric furnace 3 through a feeding trolley or the like.

[0058] In one embodiment, as Figure 1 A plurality of scrap steel preheating devices 1 can be connected in series to realize multi-stage preheating of the scrap steel 4, so as to further improve the preheating effect and efficiency of the scrap steel and improve the waste heat utilization effect of the flue gas of the electric furnace.

[0059] Embodiment three: the embodiment of the present application provides an electric furnace scrap steel preheating method based on the scrap steel preheating device 1 provided in the above embodiment one, and the method comprises the following steps:

[0060] The scrap steel 4 to be preheated is fed into the rotary cylinder 111, and the flue gas of the electric furnace is introduced into the rotary cylinder 111;

[0061] The rotary cylinder 111 is driven to rotate, and the flue gas of the electric furnace exchanges heat with the scrap steel 4 to preheat the scrap steel 4.

[0062] The rotation speed of the rotary cylinder 111, the flow rate of the flue gas of the electric furnace, the amount of scrap steel supplied to the rotary cylinder 111, the scrap steel feeding speed and the like can be controlled to control the preheating temperature of the scrap steel, so as to achieve good preheating effect and efficiency of the scrap steel.

[0063] Embodiment four: the embodiment of the present application provides a scrap steel feeding device which can be used in the scrap steel feeding section 2 in the above embodiment two.

[0064] As Figure 6 and Figure 7 The scrap steel feeding device comprises a feeding turntable 21 and a sealing hood 22, the feeding turntable 21 comprises a central rotating shaft 211 and a plurality of material separating radial plates 212, each of the material separating radial plates 212 is connected to the central rotating shaft 211 and extends radially outward, a material bin is formed between each two adjacent material separating radial plates 212, and the rotation axis of the central rotating shaft 211 is parallel to the horizontal plane and is connected with a turntable driving unit 214 for driving the rotation thereof.

[0065] The sealing hood 22 covers the feeding turntable 21, the bottom of the sealing hood 22 is open, and the top of the sealing hood 22 is provided with a scrap steel inlet 201 and a flue gas outlet 202.

[0066] Preferably, the sealed smoke hood 22 includes a smoke hood top plate 221, two first smoke hood side plates 222 arranged in parallel and opposite directions, and two second smoke hood side plates 223 arranged in parallel and opposite directions. The surface of the first smoke hood side plate 222 is perpendicular to the axis of the central rotating shaft 211, and the surface of the second smoke hood side plate 223 is parallel to the axis of the central rotating shaft 211.

[0067] Optionally, such as Figure 6 The scrap steel inlet 201 is opened on one of the second fume hood side plates 223; the scrap steel inlet 201 is preferably located on the upper part of the sealed fume hood 22 to facilitate the entry of scrap steel 4 into the feeding turntable 21. Therefore, the scrap steel inlet 201 is opened on the upper part of the second fume hood side plate 223.

[0068] Preferably, such as Figure 6 A guide plate (shown in the figure, not labeled) is provided at the bottom of the scrap steel inlet 201. The guide plate extends into the cavity of the sealed fume hood 22, which can better guide the scrap steel 4 into the feeding turntable 21.

[0069] In one embodiment, such as Figure 6 A dynamic sealing plate 2011 is provided at the scrap steel inlet 201 to dynamically seal the scrap steel inlet 201 and reduce the entry of external gas into the sealed fume hood 22. The dynamic sealing plate 2011 is movably installed at the scrap steel inlet 201 to achieve dynamic sealing, ensuring that the dynamic sealing plate 2011 is always in contact with the upper surface of the scrap steel flow during feeding, thus achieving a better sealing effect. For example, the dynamic sealing plate 2011 is hinged to the top of the scrap steel inlet 201, and the scrap steel flow can push open the dynamic sealing plate 2011. When there is no flow, the dynamic sealing plate 2011 can also close the scrap steel inlet 201 due to its own weight.

[0070] In one embodiment, such as Figure 7 The two lateral ends of the material separator 212 are respectively fitted with the two first fume hood side plates 222 with clearance, which ensures the smooth rotation of the feeding turntable 21 and also provides an upward channel for the flue gas below.

[0071] In one embodiment, the two lateral ends of the hopper (i.e., the ends near the first fume hood side plate 222) can be open, and the scrap steel 4 can be restricted by the two first fume hood side plates 222. This method can improve the heat exchange effect between the scrap steel 4 and the flue gas to a certain extent. In another embodiment, the two lateral ends of the hopper are sealed with end plates. This method can reduce the risk of the scrap steel 4 getting stuck. In this scheme, a flue gas passage 2121 can be set on the end plate. The flue gas passage 2121 can be a perforated channel, a trough channel, etc.

[0072] As a preferred option, such as Figure 7The smoke passing channel 2121 can be a hole type channel, a groove type channel, etc. By arranging the smoke passing channel 2121 on the material separation spoke 212, the heat exchange effect and efficiency between the smoke and the scrap steel 4 can be improved when the upper feeding turntable 21 is conveying the scrap steel 4.

[0073] The material separation spoke 212 preferably extends outward along the radial direction of the central rotating shaft 211, that is, extends away from the central rotating shaft 211. The central angles / dihedral angles defined between the adjacent material separation spokes 212 are preferably the same. In addition, the extension lengths of the material separation spokes 212 are preferably the same, that is, the radial outer ends of the material separation spokes 212 are distributed in a circle, so that the volumes of the material bins defined are the same.

[0074] The amount of scrap steel contained in the material bin can be controlled by the rotating speed of the upper feeding turntable 21. In addition, the number and volume of the material bins can be designed according to the demand of the electric arc furnace scrap steel material.

[0075] Preferably, as shown in FIG. 1, the upper feeding turntable 21 comprises a central rotating shaft 211, and a plurality of material separation spokes 212 arranged on the central rotating shaft 211. Figure 7 The two ends of the central rotating shaft 211 respectively pass through the two first smoke hood side plates 222 to connect the turntable driving unit 214. The turntable driving unit 214 can be driven by a motor or other driving device, and can be connected to the central rotating shaft 211 through a shaft coupling. Alternatively, a set of driving devices can be connected to the two ends of the central rotating shaft 211 to ensure the power required for the rotation of the upper feeding turntable 21.

[0076] The radial outer end of each material separation spoke 212 has a rotating track, which is defined as a turntable rotating track for convenience.

[0077] When the guide plate is arranged, the guide plate is close to the turntable rotating track.

[0078] The two second smoke hood side plates 223 are preferably tangent to or close to the turntable rotating track, for example, gap fit with the turntable rotating track (that is, gap fit with the material separation spoke 212 rotating to this position), so that the second smoke hood side plate 223 can limit the material bin rotating to this position (for example, the material bin rotating to the horizontal position) to prevent the scrap steel 4 from falling out of the material bin.

[0079] With the rotation of the upper feeding turntable 21, the scrap steel 4 is received from the scrap steel inlet 201, and then the turntable is rotated to make the bin opening of the material bin downward for unloading, so that the upper feeding turntable 21 has a turntable unloading position 203.

[0080] Preferably, as shown in FIG. 1, the upper feeding turntable 21 comprises a central rotating shaft 211, and a plurality of material separation spokes 212 arranged on the central rotating shaft 211. Figure 6The scrap steel inlet 201 and the rotary table discharging place 203 are respectively located on two sides of the reference plane, which can prolong the residence time of the scrap steel 4 in the loading rotary table 21, thereby improving the preheating effect of the flue gas on the scrap steel 4. For the case that the scrap steel inlet 201 is arranged on the second smoke hood side plate 223, the rotation of the loading rotary table 21 is used to drive the current receiving scrap steel 4 bin to swing upward instead of downward, that is, to make the scrap steel inlet 201 and the rotary table discharging place 203 respectively located on two sides of the reference plane; the rotary table discharging place 203 is close to the other second smoke hood side plate 223.

[0081] Preferably, as Figure 6 The flue gas outlet 202 and the scrap steel inlet 201 are respectively located on two sides of the reference plane, which makes the flue gas outlet 202 and the scrap steel inlet 201 away from each other, and also improves the preheating effect of the flue gas on the scrap steel 4.

[0082] Optionally, as Figure 6 The flue gas outlet 202 is arranged on the smoke hood top plate 221, adjacent to the other second smoke hood side plate 223.

[0083] As a preferred solution, as Figure 6 A limiting plate 224 is arranged at the bottom of the sealing smoke hood 22, and the limiting plate 224 is arranged at the rotary table discharging place 203 and extends to the inside of the hood cavity close to the rotary table rotating track.

[0084] The limiting plate 224 is mainly used to limit the scrap steel 4 in the bin rotating to the rotary table discharging place 203, so that the bin discharges continuously with small flow. The limiting plate 224 has a limiting surface, which is close to the rotary table rotating track, so the limiting surface is preferably an arc surface, which can be tangent to the radial outer end of the material separation spoke 212, and the distance between the arc surface and the center rotating shaft 211 axis can be slightly larger than the radius of the rotary table rotating track (that is, the distance between the radial outer end of the material separation spoke 212 and the center rotating shaft 211 axis). For example, the limiting surface and the rotary table rotating track are gap-fitted (that is, gap-fitted with the material separation spoke 212 rotating to the place).

[0085] Preferably, the limiting plate 224 is installed on the second smoke hood side plate 223, which is convenient to install. Preferably, the limiting plate 224 is detachably installed on the second smoke hood side plate 223, because it bears more scrap steel abrasion, so this way can facilitate its replacement and maintenance. It can be seen that for the case that the second smoke hood side plate 223 can limit the scrap steel 4 in the bin, the limiting plate 224 increases the limiting range of the second smoke hood side plate 223 to the loading rotary table 21 and prolongs the limiting time.

[0086] In one of the embodiments, as shown in Figure 6 The radial outer end of each of the material isolation spokes 212 is provided with a material scraping plate 213, which extends forwardly and protrudes from the plate surface of the material isolation spoke 212 along the rotation direction of the rotary disc; the outer plate surface of the material scraping plate 213 is preferably an arc-shaped plate surface which is concentric with the rotation track of the rotary disc.

[0087] When the feeding rotary disc 21 starts to unload at the rotary disc unloading position 203, the scrap steel 4 continuously falls from the stock bin, while the feeding rotary disc 21 continuously rotates. When the scrap steel 4 accumulates below the material limiting plate 224, the material scraping plate 213 can limit the remaining material in the stock bin from falling below the material limiting plate 224, or in other words, the material scraping plate 213 can push the accumulated scrap steel 4 to the rear side for accumulation. In this way, the scrap steel 4 is scattered below the feeding rotary disc 21 and the height is limited, and the scrap steel is pushed and leveled, thereby ensuring the reliability of the scrap steel feeding.

[0088] In one of the embodiments, as shown in Figure 6 The inner wall of the top of the sealing fume hood 22 is provided with a flow limiting plate 225, which has an arc-shaped flow limiting surface facing the feeding rotary disc 21, and the curvature of the arc-shaped flow limiting surface is adapted to the rotation track of the radial outer end of the material isolation spoke 212. Preferably, the flow limiting plate 225 and the scrap steel inlet 201 are located on the two sides of the above-mentioned reference surface, respectively. By providing the flow limiting plate 225, it can be matched with the gap between the material isolation spoke 212 rotating to this position and limit the passage of flue gas. On the one hand, it can promote the heat exchange between the flue gas and the scrap steel 4 in the stock bin, and on the other hand, it can maintain a certain flue gas pressure around the scrap steel inlet 201, which not only ensures the positive pressure sealing effect of the scrap steel inlet 201, but also improves the scrap steel preheating effect in this area.

[0089] The sealing fume hood 22, the material isolation spoke 212, the central rotating shaft 211, etc. are preferably designed in a water-cooled form to prolong the service life of the equipment.

[0090] When the scrap steel feeding device in this embodiment is applied to the scrap steel feeding section 2 in Embodiment Two, the scrap steel feeding section 2 also includes a horizontal feeding chute 23 (corresponding to the feeding section chute in Embodiment Two), which can be connected with the vibrator chute of the middle vibrator in Embodiment Two. The horizontal feeding chute 23 is connected with a protective fume hood, and the protective fume hood is provided with a feeding port. The open bottom end of the sealing fume hood 22 is connected with the feeding port.

[0091] The feeding rotary disc 21 partially extends into the protective fume hood, which can reduce the impact of the falling scrap steel on the horizontal feeding chute 23.

[0092] The feeding device can be a chain plate machine or a scale plate machine, which can transport the scrap steel from the platform or the ground to the scrap steel inlet 201, and then unload it into the feeding rotary disc 21.

[0093] The electric furnace flue gas successively passes through the charging trolley 2 and the scrap steel preheating device 1, and then enters the scrap steel charging device, so that multi-stage preheating of the scrap steel 4 can be realized. The electric furnace flue gas is finally discharged from the flue gas outlet 202 for subsequent treatment (for this combination, the charging smoke hood 122 in the above-mentioned embodiment two can be not connected with the flue gas outlet pipe, so that the flue gas further enters the scrap steel charging device for heat exchange).

[0094] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A scrap steel preheating device, characterized in that, It includes a rotary material cylinder and a rotary drive mechanism for driving the rotary material cylinder to rotate. Multiple inner material grooves are formed on the inner wall of the rotary material cylinder. Each inner material groove extends from one end of the rotary material cylinder to the other end and is arranged sequentially along the circumference of the rotary material cylinder.

2. The scrap steel preheating device as described in claim 1, characterized in that: The planes containing the walls of the two adjacent inner material troughs in each group intersect.

3. The scrap steel preheating device as described in claim 2, characterized in that: The walls of the two inner material troughs of each group, which are adjacent and belong to two different inner material troughs, intersect.

4. The scrap steel preheating device as described in claim 2, characterized in that: The dihedral angle between the planes containing the walls of the two adjacent inner material troughs in each group is within the range of 80° to 150°.

5. The scrap steel preheating device as described in claim 1, characterized in that: One end of the rotary feed cylinder is connected to a feeding section and is rotatable relative to the feeding section. The feeding section includes a feeding trough and a feeding fume hood covering the feeding trough. The other end of the rotary drum is connected to a discharge section and is rotatable relative to the discharge section. The discharge section includes a discharge trough and a discharge fume hood covering the discharge trough.

6. The scrap steel preheating device as described in claim 5, characterized in that: It also includes a synchronization frame, the lower part of which is fixedly connected to the feed trough and the discharge trough respectively, and the upper part of which is fixedly connected to the feed fume hood and the discharge fume hood respectively; the feed trough is connected to a vibrator or to a vibrator feed trough.

7. The scrap steel preheating device as described in claim 5, characterized in that: The bottom of the feed trough, the bottom of the rotary cylinder cavity, and the bottom of the discharge trough are arranged at different heights in sequence.

8. The scrap steel preheating device as described in claim 1, characterized in that: The rotary drum is also equipped with an axial limiting mechanism to restrict its axial displacement.

9. An electric arc furnace scrap steel feeding system, comprising a scrap steel feeding section, characterized in that, It also includes the scrap steel preheating device as described in any one of claims 1 to 8, wherein the rotary drum is connected and cooperated with the scrap steel feeding section and the electric furnace scrap steel inlet respectively.

10. A method for preheating scrap steel in an electric furnace, characterized in that, The method is implemented based on the scrap steel preheating device according to any one of claims 1 to 8, and includes: The scrap steel to be preheated is fed into the rotary drum, and the electric furnace flue gas is introduced into the rotary drum. The rotary drum is driven to rotate, and the scrap steel is preheated by exchanging heat with the electric furnace flue gas.

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