TECHNICAL FIELD

[0001] The present disclosure, in general, relates to a gate for controlling the flow of slag in blast furnaces and in particular to a system for controlling the flow of molten slag during iron making process at a stage when the molten slag is required to be separated from hot metal while flowing out of cast house in a blast furnace.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] In the usual iron making process, iron ore, iron scrap, and fluxes (limestone and/or dolomite) are charged into a blast furnace along with coke for acting as a fuel. The coke is combusted to produce carbon monoxide, which reduces the iron ore into a molten iron product. This molten iron product can be further cast into iron products but is most often used as a feedstock for steel production.
[0004] Blast furnace slag is a non-metallic coproduct produced in the above-explained iron making process. The blast furnace slag consists primarily of silicates, alumina-silicates, and calcium-alumina-silicates. This molten slag, which absorbs much of the sulfur from the charge, comprises about 30 percent by mass of iron production.
[0005] Thus, in such an iron-making process, when the hot metal is produced in a blast furnace, impurities fused with the metal are produced as a by-product. When the hot metal is tapped from tap holes of blast furnace, molten slag also comes along with the hot metal, the place where hot metal is separated from slag is called cast house and the arrangement which is used to separate it is called skimmer. The separated hot metal is filled into ladles and sent to different processing units for further use like conversion to pig iron and steel etc.
[0006] Different forms of slag products are produced depending on the method used to cool the molten slag. These products include air-cooled blast furnace slag (ACBFS), expanded or foamed slag, pelletized slag, and granulated blast furnace slag as explained below.
[0007] Air-Cooled Blast Furnace Slag is formed if the liquid slag is poured into beds and slowly cooled under ambient conditions, a crystalline structure is formed, and a hard, lump slag is produced, which can subsequently be crushed and screened.
[0008] Expanded or Foamed Blast Furnace Slag is formed if the molten slag is cooled and solidified by adding controlled quantities of water, air, or steam, the process of cooling and solidification can be accelerated, increasing the cellular nature of the slag and producing a lightweight expanded or foamed product. Foamed slag is distinguishable from air-cooled blast furnace slag by its relatively high porosity and low bulk density.
[0009] Pelletized Blast Furnace Slag is formed if the molten slag is cooled and solidified with water and air quenched in a spinning drum, pellets, rather than a solid mass, can be produced. By controlling the process, the pellets can be made more crystalline, which is beneficial for aggregate use, or more vitrified (glassy), which is more desirable in cementitious applications. More rapid quenching results in greater vitrification and less crystallization.
[0010] Granulated Blast Furnace Slag is formed if the molten slag is cooled and solidified by rapid water quenching to a glassy state, little or no crystallization occurs. This process results in the formation of sand size (or frit-like) fragments, usually with some friable clinker-like material. The physical structure and gradation of granulated slag depend on the chemical composition of the slag, its temperature at the time of water quenching, and the method of production. When crushed or milled to very fine cement-sized particles, ground granulated blast furnace slag (GGBFS) has cementitious properties, which make a suitable partial replacement for or additive to Portland cement.
[0011] The slag after separation at skimmer is handled in slag runner and mainly it diverted towards a slag granulation plant for granulation but in case of any abnormality, the molten hot slag at 1500oC is diverted towards an emergency slag pit. It is the area where hot slag is discharged in case of unavailability of equipment at slag granulation unit or also in case of poor slag chemistry which reduces its flow-ability.
[0012] These conditions may arise during the normal hot metal making process and in running condition diversion of slag is done. To divert this slag as mentioned above, it is required to stop the flow of slag towards slag granulation plant and open the gates of dry pit side runner so that molten hot slag flow by gravity towards dry pit.
[0013] In the conventional forms of diverter gates provided for controlling the flow of molten slag in blast furnaces, the diversion of molten slag from the slag granulation unit to the emergency dry pit is carried out through the manual operation of gates located at the emergency dry pit and slag granulation unit at the cast house. Such a manual operation of gates requires dedicated manpower for operating the gate for diverting the molten slag from the emergency dry pit to the slag granulation unit or vice-versa depending upon the circumstances.
[0014] In the view of the above-cited problems, there is a need for such a diverter gate which can be operated in a safe manner from a distance in such a way that there is no direct interface between the human effort and the flow of hot molten slag in cast house of the blast furnace.
[0015] Accordingly, there is a need for a system that can overcome one or more limitations stated above or any other limitation associated with the conventional prior arts.
OBJECTS OF THE DISCLOSURE
[0016] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0017] It is a general object of the present disclosure to provide for system for controlling the flow of slag in blast furnaces upon its separation from hot metal in the iron making process.
[0018] It is another object of the present disclosure to ensure that the slag is separated from hot metal and the flow of the slag is diverted from the slag granulation unit to a slag granulation unit or an emergency dry pit when the slag granulation unit is not operational.
[0019] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY
[0020] This summary is provided to introduce concepts related to a system for controlling the flow of molten slag during the iron making process. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0021] In an embodiment, the present disclosure provides a slag diverter system for controlling a flow of molten slag during iron making process. The slag diverter system includes a compressed air supply unit for supplying compressed air from an air tank when actuated by an operator; a filter regulator lubrication unit for receiving the compressed air to filter impurities from the compressed air and to add lubricants for required oiling of the downstream components; a multi-way direction control valve coupled to the filter regulator lubrication unit, to supply the compressed air to one side of pistons of each of a pair of pneumatic cylinders and to release the compressed air from other side of the pistons of the pneumatic cylinders, for moving the pistons up and down. The slag diverter system further includes a slag diverter gate which is coupled at its both ends with respective piston rods for getting lifted and lowered, based on the movement of the piston rods connected to the pistons of the pneumatic cylinders.
[0022] In an aspect, the compressed air supply unit (302) supplies the compressed air when the compressed air inside the air tank reaches a predefined pressure level.
[0023] In an aspect, the filter regulator lubrication unit includes an air booster to reduce or increase the pressure of the compressed air.
[0024] In an aspect, the multi-way direction control valve is a 5/2-way direction control valve.
[0025] In an aspect, the slag diverter system is remotely controllable from a remotely located control station for controlling the lifting and lowering of the slag diverter gate.
[0026] In an aspect, the slag diverter gate includes a frame having two vertical members and a horizontal member forming a bridge at the top of the vertical members, wherein bases of the vertical members are mounted on top of a slag runner, a connection bar coupled horizontally between the vertical members of the frame, a stopper plate mounted on the connection bar in such a way that the stopper plate is supported on both sides in the guides formed on the vertical members of the frame and pneumatic cylinders connected to the respective longitudinal ends of the connection bar for lifting and lowering of the stopper plate mounted on the connection bar.
[0027] In an aspect, the slag diverter gate includes a plurality of wheels which are coupled with the vertical members, wherein the wheels are coupled above the connection bar and the wheels are coupled below the connection bar.
[0028] In an aspect, the slag diverter gate comprises a pair of locking pins pinned on the vertical members of the slag diverter gate positioned such that the locking pins lock the connection bar with the slag diverter gate.
[0029] In an aspect, the slag diverter gate is provided at the entrance of a slag granulation unit and an emergency dry pit.
[0030] In an aspect, the slag diverter system operates such that when the slag diverter gate provided at the slag granulation unit is closed then the slag diverter gate provided at the emergency dry pit is opened.
[0031] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[0032] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0033] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:
[0035] FIG. 1 illustrates a schematic view of a slag diverter gate for controlling the flow of slag in blast furnaces;
[0036] FIG. 2 illustrates a schematic view of a layout plan of a blast furnace cast house;
[0037] FIG. 3A illustrates a block diagram of a slag diverter system opening the slag diverter gate in accordance with an embodiment of the present disclosure; and
[0038] FIG. 3B illustrates a block diagram of a slag diverter system closing the slag diverter gate in accordance with an embodiment of the present disclosure.
[0039] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer-readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[0040] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0041] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0043] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0044] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0045] Embodiments explained herein pertain to a slag diverter gate that controls the flow of molten slag during iron making process at a stage when the molten slag is required to be separated from hot metal while flowing out of the blast furnace.
[0046] FIG. 1 illustrates a schematic view of a slag diverter gate 100 in accordance with an embodiment of the present disclosure. The slag diverter gate 100 provided in a cast house of a blast furnace for controlling the flow of molten slag during iron making process at a stage when the molten slag is required to be separated from hot metal while flowing out from the cast house in blast furnace.
[0047] In an aspect, the slag diverter gate 100 includes a frame 101 having two vertical members 105a, 105b, and a horizontal member 110 forming a bridge at the top of the vertical members 105a, 105b. Bases of the vertical members 105a, 105b are mounted on top of a slag runner 102, a connection bar 104 coupled horizontally between the vertical members 105a, 105b of the frame 101, a stopper plate 106 mounted on the connection bar 104 in such a way that the stopper plate 106 is supported on both sides in the guides formed on the vertical members 105a, 105b of the frame (101) and a pneumatic cylinder 107a, 107b connected to each longitudinal end of the connection bar 104 for lifting and lowering of the stopper plate 106 mounted on the connection bar 104.
[0048] Further, as shown in in FIG. 1, the slag diverter gate 100 includes a plurality of wheels 108a, 108b, 108c, and 108d coupled with the vertical members 105a, 105b. A first set of the wheels 108a and 108b are coupled above the connection bar 104, and a second set of the wheels 108c and 108d are coupled below the connection bar 104.
[0049] The slag diverter gate 100 further includes a pair of locking pins 109a, 109b pinned on the vertical members 105a, 105b of the slag diverter gate 100 positioned such that the locking pins 109a, 109b lock the connection bar 104 with the slag diverter gate 100.
[0050] FIG. 2 illustrates a schematic view of a layout plan of a blast furnace cast house 200, wherein one slag diverter gate 100 is provided at an entrance of the emergency dry pit 201 and another slag diverter gate 100 at the entrance of the slag granulation unit 202. The slag diverter gate 100 operates such that when the slag diverter gate 100 provided at the slag granulation unit 202 is closed or is not opening due to any technical or mechanical issue, then the slag diverter gate 100 provided at the emergency dry pit 201 is opened to divert the flow of molten slag into the emergency dry pit 201.
[0051] Further, as shown in FIG. 2, the overall layout of the blast furnace cast house 200 includes a blast furnace 207 in which hot metal is produced along with by-product non-metallic molten slag. Both hot metal and slag is tapped from a common tap hole from blast furnace and handled in a common iron tough 206. A skimmer 203 is provided wherein hot metal is separated from molten slag and the hot metal is further filled in a transport vessel 204 using runners 205. The molten slag is diverted towards the slag granulation unit 202, or towards the emergency dry pit 201 using the slag runner 102. The diversion of slag in either side is done with the help of two slag diverter gates 100.
[0052] For operating or controlling the opening and closing of the slag diverter gates 100, a slag diverter system 300 shown in FIGS. 3A and 3B is implemented in accordance with an embodiment of the present disclosure. The slag diverter system 300 is remotely controllable from a remotely located control station for controlling the lifting and lowering (opening and closing) of the slag diverter gate 100.
[0053] The slag diverter system includes a compressed air supply unit 302. The compressed air supply unit 302 may include an air tank in which the atmospheric air is feed through check (or plate) valves, then a piston cylinder is used to compress that air up to a predefined pressure level.
[0054] When the compressed air inside the air tank reaches the predefined pressure level and when the compressed air supply unit 302 is actuated by an operator, the compressed air supply unit 302 supplies the compressed air from the air tank to a filter regulator lubrication unit 304.
[0055] The filter regulator lubrication unit 304 may include an air booster to reduce or increase the pressure of the compressed air.
[0056] Also, as the name of the unit suggests, the filter regulator lubrication unit 304 may filter impurities from the compressed air and adds lubricants for required oiling of the downstream components including pneumatic cylinders 107a, 107b).
[0057] The processed or filtered compressed air then forwarded towards a multi-way direction control valve 306, The valve 306 directs the compressed air towards one side of pistons 308a, 308b of the respective pneumatic cylinders 107a, 107b, and to release the compressed air coming out from other side of the pistons 308a, 308b of the pneumatic cylinders 107a, 107b, for moving the pistons 308a, 308b up and down.
[0058] For example, as shown in FIG. 3A, when the valve 306 directs the compressed air towards the lower side of the pistons 308a, 308b, piston rods 310a, 310b start moving towards upside and the compressed air on the upper side of the pistons 308a, 308b is released into atmosphere by the valve 306. The top end of the piston rods 310a, 310b is connected to longitudinal ends of the connection bar 104 of the slag diverter gate 100. Accordingly, when the piston rods 310a, 310b moves toward upside, the connection bar 104 supporting the stopper plate 106 raises above the ground and opens the slag diverter gate 100.
[0059] Similarly, as shown in in FIG. 3B, when the valve 306 directs the compressed air towards the upper side of the pistons 308a, 308b, piston rods 310a, 310b start moving towards downside and the compressed air on the lower side of the pistons 308a, 308b is released into atmosphere by the valve 306. The top end of the piston rods 310a, 310b is connected to longitudinal ends of the connection bar 104 of the slag diverter gate 100. Accordingly, when the piston rods 310a, 310b moves toward downside, the connection bar 104 supporting the stopper plate 106 is lowered till the ground and closes the slag diverter gate 100.
[0060] In an aspect, the multi-way direction control valve (306) is a 5/2-way direction control valve.
[0061] As mentioned above, the slag diverter system 300 is remotely controllable from a remotely located control station for controlling the lifting and lowering (opening and closing) of the slag diverter gate 100. By having such a system, the diverter gate 100 can be operated in a safe manner from a distance in such a way that there is no direct interface between the human effort and the flow of hot molten slag in cast house of the blast furnace.
[0062] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
Equivalents:
A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention. When a single device or article is described herein, it will be apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.
[0063] The specification has described slag diverter gate (100) which controls the flow of molten slag during iron making process when the molten slag is required to be separated from hot metal while flowing out of the blast furnace (207).
[0064] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

We Claim:

1. A slag diverter system (300) for controlling a flow of molten slag during iron making process, the slag diverter system (300) comprising:
a compressed air supply unit (302) supplying compressed air from an air tank when actuated by an operator;
a filter regulator lubrication unit (304) receiving the compressed air to filter impurities from the compressed air and to add lubricants for required oiling of the downstream components;
a multi-way direction control valve (306) coupled to the filter regulator lubrication unit (304), to supply the compressed air to one side of pistons (308a, 308b) of respective pneumatic cylinders (107a, 107b) and to release the compressed air from other side of the pistons (308a, 308b) of the pneumatic cylinders (107a, 107b), for moving the pistons (308a, 308b) up and down; and
a slag diverter gate (100) being coupled at its both ends with respective piston rods (310a, 310b) for getting lifted and lowered, based on the movement of the piston rods (310a, 310b) connected to the pistons (308a, 308b) of the pneumatic cylinders (107a, 107b).
2. The slag diverter system (300) as claimed in claim 1, wherein the compressed air supply unit (302) supplies the compressed air when the compressed air inside the air tank reaches a predefined pressure level.
3. The slag diverter system (300) as claimed in claim 1, wherein the filter regulator lubrication unit (304) comprises an air booster to reduce or increase the pressure of the compressed air.
4. The slag diverter system (300) as claimed in claim 1, wherein the multi-way direction control valve (306) is a 5/2-way direction control valve.
5. The slag diverter system (300) as claimed in claim 1, wherein the slag diverter system (300) is remotely controllable from a remotely located control station for controlling the lifting and lowering of the slag diverter gate (100).
6. The slag diverter system (300) as claimed in claim 1, wherein the slag diverter gate (100) comprising:
a frame (101) having two vertical members (105a, 105b) and a horizontal member (110) forming a bridge at top of the vertical members (105a, 105b), wherein bases of the vertical members (105a, 105b) are mounted on top of a slag runner (102);
a connection bar (104) coupled horizontally between the vertical members (105a, 105b) of the frame (101);
a stopper plate (106) mounted on the connection bar (104) in such a way that the stopper plate (106) is supported on both sides in the guides formed on the vertical members (105a, 105b) of the frame (101); and
the pneumatic cylinders (107a, 107b) connected to respective longitudinal ends of the connection bar (104) for lifting and lowering of the stopper plate (106) mounted on the connection bar (104).
7. The slag diverter system (300) as claimed in claim 6, wherein the slag diverter gate (100) comprises a plurality of wheels (108a,108b,108c,108d) coupled with the vertical members (105a, 105b), wherein a first set of the wheels (108a, 108b) are coupled above the connection bar (104) and a second set of the wheels (108c, 108d) are coupled below the connection bar (104).
8. The slag diverter system (300) as claimed in claim 6, wherein the slag diverter gate (100) comprises a pair of locking pins (109a,109b) pinned on the vertical members (105a, 105b) of the slag diverter gate (100) positioned such that the locking pins (109a,109b) lock the connection bar (104) with the slag diverter gate (100).
9. The slag diverter system (300) as claimed in claim 6, wherein the slag diverter gate (100) is provided at the entrance of a slag granulation unit (202) and an emergency dry pit (201).
10. The slag diverter system (300) as claimed in claim 9, wherein the slag diverter system (300) operates such that when the slag diverter gate (100) provided at the slag granulation unit (202) is closed then the slag diverter gate (100) provided at the emergency dry pit (201) is opened.