Furnace Coupling System

Abstract

The furnace coupling and adjustment system 14 includes a frame 18 exterior to the walls 16.1 and 16.2 of the furnace 12. Adjustable spring-loaded actuators 22, 24 are provided, selectable from the group including: a) a first actuator 22 configured to apply an adjustable repulsive force between the frame 18 and the furnace wall; and b) a second actuator 24 configured to apply an adjustable tension force to a tie rod assembly 26 of the coupling system. A sensing device 28 is associated with at least some of the actuators. The sensing device has a signal output 30 for a signal indicative of the force applied by the actuator. A remote control device 32 is in signal communication with each output and is configured to generate data in response to the output signal for use in adjusting the force applied by at least some of the plurality of actuators.

Description

[Technical Field]

[0001] The present invention relates to metallurgical furnaces, and more particularly to coupling and adjustment systems for furnaces. [Background technology]

[0002] Metallurgical furnaces are used to process iron ore and non-ferrous metal ores in smelted and / or molten form. These furnaces are generally circular or rectangular in shape, with a hearth and upstanding walls made of refractory brick, and a roof. In rectangular furnaces, the hearth and walls are typically exteriorly clad with metal cladding. Spaced-apart exterior frame members are used to secure and support the furnace walls. The frame members are interconnected and held in place by a combination of rigid members and flexible connection systems. The connection system typically includes multiple tie rod assemblies extending vertically from one end of the furnace to the other, below the hearth and above the roof. Laterally, the connection system typically includes a group of independent connection actuators secured to a frame member and extending between the frame member and the furnace sidewall.

[0003] During use and as a result of the smelting or melting process within the furnace, the furnace walls, frame, tie rod assemblies, and independent actuators are subjected to significant thermal and mechanical forces. The tie rod assemblies and independent actuators include tensioning means for maintaining compressive forces on the hearth and furnace walls.

[0004] The introduction to U.S. Patent No. 6,814,012 states that it is known to use compression spring sets as tensioning means and lists and describes various disadvantages of compression spring sets. One such disadvantage is that known spring sets require manual adjustment to ensure that the compressive force on the hearth and side walls remains relatively constant during furnace use. U.S. Patent No. 6,814,012 teaches away obstacles related to spring sets and discloses a tie rod assembly with a fluid-pressurized tensioning means. In the applicant's view, fluid-pressurized tensioning means are unsuitable for at least some applications because they may prove unreliable in maintaining the desired force under certain operating conditions. Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to provide a coupling and regulating system for a furnace which the applicant believes may at least reduce the above-mentioned disadvantages or which may be a useful alternative to known systems. [Means for solving the problem]

[0006] According to the invention, there is provided a coupling and adjustment system for a furnace including a wall, the coupling and adjustment system comprising: a frame located outside the wall, the frame including a plurality of frame members, at least some of the frame members being arranged in pairs across the furnace; a plurality of adjustable spring actuators including at least one of: a) a first type of adjustable spring actuator configured to apply an adjustable repulsive force between the frame and a wall of the furnace; and b) a second type of adjustable spring actuator configured to apply an adjustable tension to a tie rod assembly extending between a pair of frame members; a sensing device associated with one of at least some of the plurality of adjustable spring actuators, the sensing device having an electronic signal output for providing an output signal indicative of the force exerted by the corresponding adjustable spring actuator; a remote computer controller in signal communication with the electronic signal output and configured to generate data in response to the output signal for use in adjusting the force exerted by at least some of the plurality of adjustable spring actuators.

[0007] The adjustable spring actuator may be adjustable by an electromechanical device.

[0008] The remote computer controller may include an output device, and the remote computer controller may be configured to provide, at the output device, control signals derived from the data for controlling the electromechanical device.

[0009] Each of the plurality of adjustable spring actuators may comprise a compression spring.

[0010] Each of the plurality of adjustable spring actuators may include a cylinder having a first end and a second end, and the compression spring may include an elongated coil spring, cup spring, or disc spring defining a bore and having a first end and a second end, and the elongated compression spring may be located within the cylinder.

[0011] The first type of adjustable spring actuator may include a first movable piston adjacent a first end of the compression spring and a second movable piston adjacent a second end of the compression spring, the first movable piston may extend beyond a first end of the cylinder and terminate in an abutment structure that abuts a wall of the furnace in use, and the second movable piston may extend beyond a second end of the cylinder and abut a first adjustment structure on a first rod directly or indirectly via a first sandwich arrangement of axially movable members, the first sandwich arrangement may include a first collar structure directly adjacent the first adjustment structure, and the first adjustment structure may be axially adjustable on the first rod to adjust the compression of the compression spring.

[0012] The second adjustable spring actuator may include a movable piston defining a bore, and a cylinder of the second adjustable spring actuator may be mounted on the tie rod assembly with a rod of the assembly passing through the bore of the compression spring and the bore of the movable piston, the movable piston abutting a second adjustment structure directly or indirectly through a second sandwich arrangement of axially movable members, the second sandwich arrangement may include a second collar structure directly adjacent the second adjustment structure, and the second adjustment structure may be axially adjustable on the tie rod to adjust the compression of the compression spring.

[0013] At least one of the first adjustment structure and the second adjustment structure may include a threaded nut located on a threaded portion of each of the first rod and the tie rod.

[0014] The nut may be manually operable to adjust its axial position.

[0015] The furnace coupling and adjustment system may include a remotely controllable nut release device and a remotely controllable nut manipulation device controlled by the remote computer controller.

[0016] The remotely controllable nut release device may include a fluid pressure actuated mechanism for operating the axially movable first or second collar structure to release the nut by axially moving the first or second collar structure away from the nut against the bias of the compression spring.

[0017] The remotely controllable nut operating device may include a rotatable structure defining a socket having a suitable shape for receiving at least a portion of the nut, and means for rotatably driving the rotatable structure in selectable one of a clockwise direction and a counterclockwise direction.

[0018] The drive means includes an electric motor and a drive train connected between the rotatable structure and the electric motor.

[0019] The remote computer controller may be configured, in response to the output signal, to generate control signals for controlling the nut release devices of designated ones of the plurality of adjustable spring actuators to release the nuts of those designated actuators and then cause the nut operating devices of those designated actuators to operate the nuts.

[0020] At least one of the first sandwich configuration and the second sandwich configuration may include a first sensing device. [Brief explanation of the drawings]

[0021] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0022] FIG. 1 is a schematic perspective view of a furnace system including a rectangular furnace and a furnace bonding and adjustment system for providing structural integrity to the furnace during operation; FIG. 2 is a perspective view of a tie rod assembly including interconnected tie rod segments, an adjustable spring actuator, and first and second load sensing devices; FIG. 3 is a schematic perspective view of a second load sensing device on a tie rod; FIG. 4 is a block diagram of first and second load sensing devices connected to a first local station connected to a remote computer controller in a control room; FIG. 5 is a schematic perspective view (partially cut away) of a first adjustable spring actuator for applying an adjustable repulsive force between the frame and the side wall of the furnace; FIG. 6 is a cross-sectional view of a second adjustable spring actuator for applying adjustable tension to the tie rod assembly; FIG. 7 is a schematic perspective view of a second embodiment of a second adjustable spring actuator; FIG. 8 is a cross-sectional view of the actuator of FIG. 7 with the nut release mechanism in a first normal operating configuration; FIG. 9 is a view similar to FIG. 8 but showing the nut release mechanism in a second configuration allowing remotely controlled automatic electromechanical adjustment of the nut; FIG. 10 is a view similar to FIG. 1, but with bidirectional communication between the remote computer controller and the load sensing device on the one hand, and between the remote computer controller and the electromechanically adjustable spring actuator of the combined system on the other hand; FIG. 11 is a diagram similar to FIG. 4, but showing the two-way communication of FIG. 10 in more detail; 12(a) and 12(b) are schematic diagrams illustrating a first alternative or additional load sensing mechanism; 13(a) and 13(b) are schematic diagrams illustrating a second alternative or additional load sensing mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0023] 1 shows an exemplary embodiment of a furnace system 10 including a rectangular furnace 12 and a coupling and adjustment system 14 for the furnace. The furnace has opposing furnace end walls 16.1 and opposing furnace side walls 16.2 made of refractory material that define an interior hearth (not shown). Walls 16.1 and 16.2 are metallized in a known manner.

[0024] The furnace coupling and adjustment system 14 includes a frame 18 external to the wall. The frame includes a plurality of frame members 20.1, 20.2, through 20.n, with at least some of the frame members, e.g., members 20.1 and 20.2, arranged in pairs across the furnace 12. A plurality of adjustable spring actuators 22 and 24 are provided. The actuators can be selected from a) a first type of adjustable spring actuator 22 configured to apply a repulsive force between the frame 18 and the furnace walls 16.1 and 16.2, and b) a second type of adjustable spring actuator 24 configured to apply an adjustable tension to a tie rod assembly 26 extending between the pair of opposing frame members 20.1 and 20.2. A first sensing device 28 is associated with at least some of the adjustable spring actuators 22 and 24. The first sensing device 28 has electronic signal outputs 30 (best shown in Figures 1, 4, 5, and 6) for providing output signals indicative of the force applied by the corresponding adjustable spring actuators 22, 24. A remote computer controller 32 (shown in Figure 4) is in signal communication with each electronic signal output 30 and is configured to generate data in response to the output signals for use in adjusting the force applied by at least some of the plurality of adjustable spring actuators 22, 24, as described in more detail below.

[0025] FIG. 2 illustrates an exemplary embodiment of the tie rod assembly 26. The tie rod assembly 26 comprises a tie rod 34 including at least a first tie rod portion or segment 34.1 and a second tie rod portion 34.2. A second type of adjustable spring actuator 24 is attached to the tie rod 34 and configured to apply tension to the tie rod 34 extending between the opposing frame members 20.1 and 20.2. The tie rod assembly 34 further comprises a body 38 having a major axis 40 (as best shown in FIG. 3 ), a second sensing device 36 including a first connector 42 for connecting the first tie rod portion 34.1 to the body, and a second connector 44 for connecting the second tie rod portion 34.2 to the body. The first and second connectors are spaced apart from one another along the major axis. The second sensing device 36 includes a strain gauge 46 supported on the body 38 for measuring tension applied to the body 38 during use. Tie rod assembly 26 further includes a first sensing device 28 (best shown in FIGS. 2 and 4) configured to sense a compressive force between a member on the tie rod, such as a nut 48, and actuator 24. Nut 48 is normally stationary on the tie rod, but its position is selectively adjustable axially to adjust spring compression, as described below.

[0026] Although only a rectangular furnace 12 is illustrated, it will be understood that the furnace may have any other suitable shape, such as circular, and that similar coupling systems may be employed, if suitably adapted.

[0027] 1, furnace 12 is of known construction and includes furnace walls including opposed, metallized, vertically extending end walls 16.1 and opposed, metallized, vertically extending side walls 16.2, which collectively define a hearth toward a bottom interior region of the furnace, and a roof 50. The hearth and walls are constructed of refractory brick. An electrode (not shown) extends through the roof into the furnace.

[0028] Coupling system 14 typically includes a frame 18 (spaced apart frame members 20.1-20.n), a plurality of tie rod assemblies 26, and a plurality of first-type adjustable spring actuators 22. Some tie rod assemblies extend below the hearth between opposing frame members adjacent opposite end walls 16.1, while other tie rod assemblies extend above roof 50 between opposing frame members adjacent the opposite end walls. The first-type adjustable spring actuators 22 are mounted between adjacent frame members, such as members 20.3 and 20.4 in FIG. 1, to apply a reaction force between the frame and the wall.

[0029] The first load sensing device 28 may be, for example, a device such as that supplied by Earth System srl under the name "Anchor load cell", which is ring-shaped and has an electronic signal output 30 for a signal indicative of the pressure or compressive force sensed by the first load sensing device 28.

[0030] The second load sensing device 36, which senses strain on the body 38, is fully described in applicant's International Application No. PCT / IB2020057950, entitled "Load Monitoring Device," the contents of which are incorporated herein by reference. The strain gauges 46 of the second load sensing device 36 have electronic signal outputs 52 (shown in FIG. 4) for signals indicative of the strain sensed by the second load sensing device 36.

[0031] The first type of adjustable spring actuator 22 is best shown in FIG. 5. These actuators are mounted between adjacent frame members, such as frame members 20.3 and 20.4. Each actuator includes a cylinder 54 having a first end 56 and a second end 58. A compressed compression spring 60 having a first end and a second end is positioned within the cylinder. The first end of the compression spring abuts, directly or indirectly (through any other member), a first movable piston 62 that extends beyond the first end of the cylinder and abuts the furnace sidewall 16.2. The second end of the compression spring abuts, directly or indirectly (through any other member) a second movable piston 64. The second movable piston extends beyond the second end of the cylinder and abuts, directly or indirectly through a first sandwich arrangement 66 of axially movable members, a first adjustment structure 68 (in the form of an internally threaded nut in this exemplary embodiment) on the externally threaded portion of a first rod 70 that is rigidly attached to the frame 20. The first sandwich arrangement 66 includes a first collar structure 72 directly adjacent the nut 68. The nut 68 is axially adjustable on the first rod to adjust the compression of the compression spring 60. The first sandwich arrangement 66 also includes a first load sensing device 28 having an output 30.

[0032] The second type of adjustable spring-type actuator 24 is best shown in FIG. 6. The actuator 24 includes a compression spring 80 (in this embodiment, in the form of an elongated compression spring) positioned within a cylinder 82 having a first end 84 and a second end 86. The actuator further includes a movable piston 88 defining a bore 90. A tie rod 34 extends through the cylinder and the bore 90. The cylinder is attachable at one end 84 to a fixed frame member 20.1. The compression spring 80 abuts, directly or indirectly, against the movable piston 88. The movable piston 88 extends beyond the second end 86 of the cylinder and abuts, directly or indirectly via a second sandwich arrangement 92 of axially movable members, a second adjustment structure 94, which in this embodiment is in the form of an internally threaded nut on an externally threaded end 98 of the tie rod 34. The second sandwich arrangement 92 includes a second collar structure 96 directly adjacent the nut 94. The nut 94 is axially adjustable on the tie rod 34 to adjust the compression of the compression spring. The second sandwich arrangement 92 also includes a first sensing device 28 having an output 30. The nut 94 cooperates with a threaded portion of the tie rod when manipulated and is used to adjust the compression of the spring, and therefore the tension applied to the tie rod 34, in use.

[0033] As best shown in Figures 1 and 4, the electronic signal outputs 30 and 52 are connected by electrical wires 100 and 102, respectively, to a first local station 104 located within suitable proximity of the furnace 12. The first station 104 may be in the form of a junction panel. As best shown in Figure 4, the first station 104 is in signal or data communication with a second station, which may be located in a control room 106. In this exemplary embodiment, the control room 106 houses the remote computer controller 32. The controller may include a computer system or server 108, a database 110 connected to the server, and a monitor 112 for use by a human operator 114.

[0034] The output signals or data from the first and second sensing devices 28, 36 on the plurality of tie rod assemblies 16 and on the actuators 22 are processed under the control of a computer program running on the computer controller 32, and the resulting data is displayed on a monitor. This data enables the operator 114 to instruct another human operator (not shown) to go to the furnace and manually manipulate the nuts 68, 48 of the designated actuators 22, 24 with an appropriate tool (not shown), thereby adjusting the compression of the corresponding compression spring and the force applied by that actuator 22, 24.

[0035] A second embodiment of the second type of actuator 24 is shown in Figures 7-9 and is generally designated 120. The second embodiment of the second actuator 120 comprises the actuator 24 (as described above with reference to Figure 6), a remotely controllable hydraulic actuator 122 (best shown in Figures 8 and 9) for releasing the nut 94 from the collar structure 96, and a remotely controllable nut operating device 124. It will be appreciated that a second embodiment 121 of the first type of actuator 22 (shown in Figure 11) may comprise a similar remotely controllable nut release device and a similar remotely controllable nut operating device that operates in a similar manner as described below with respect to this second embodiment of the second type of actuator 120.

[0036] 8 and 9, the nut release device 122 comprises a cylinder-and-piston assembly 126 including a hydraulic cylinder 128 threadedly engaged with the threaded end 98 of the tie rod 34. A cooperating cylindrical piston portion 130 has one end 132 defining an opening 134 large enough to allow the nut 94 to pass therethrough. The piston portion 130 is coaxially mounted on the tie rod with its end 132 abutting the collar structure 96. The assembly 126 defines an annular chamber 136 for pressurized fluid, preferably hydraulic oil. A remotely controllable pump (not shown) controls the introduction and withdrawal of hydraulic oil into and from the chamber 136 via a conduit 138.

[0037] In a first or normal operating configuration of the tie rod assembly (shown in FIG. 8 ), the nut 94 abuts the collar structure 96 as described above. The nut can be released from the collar structure 96 by introducing hydraulic fluid into the chamber 136. This causes the chamber 136 to expand, moving the cylindrical piston 130, its end 132, the collar structure 96, and the second sandwich arrangement between the end 132 and the movable piston 88 (including the first sensing device 28) in a direction A away from the nut 94, thereby releasing the nut from the collar structure 96 and thereby rendering the nut 94 operable.

[0038] Nut operating device 124 includes a rotatable member 140 defining a suitably shaped socket for receiving nut 94. Member 140 is selectively rotatable in a clockwise or counterclockwise direction by an electric motor 142 via a shaft 144 and a gear train 146 housed in a gear box 148.

[0039] As best shown in Figures 10 and 11, the pumps and electric motors for the nut release device 122 and nut operating device 124, respectively, of the second embodiment 120 of the second type of actuator, and the pumps and electric motors for the nut release device and nut operating device, respectively, of the second embodiment 121 of the first type of actuator, are controllable by control signals 150 from the remote computer controller 32 in the control room 106.

[0040] Thus, in use, when the computer controller 32 determines from the signals 152 received from the sensing devices 28, 36 that the compression spring 60, 80 of any one of the plurality of actuators 120, 121 needs adjustment, the required control signal 152 is generated, first driving the pump with control signal 154 to release the appropriate nut 48, 68 (as described above), and then driving the electric motor with control signal 156 to manipulate the released nut in the required direction. The second embodiment of the first type actuator 120 and the second embodiment of the second type actuator 121, and the two-way signal communications 152, 150, 154, 156 shown in FIG. 11 , eliminates the need for a separate human operator to manually manipulate the appropriate indicated nut 48, 68.

[0041] A first alternative and / or additional load sensing mechanism 200 is shown in Figures 12(a) and 12(b), and a second alternative or additional load sensing mechanism 300 is shown in Figures 13(a) and 13(b).

[0042] Referring to the second type of actuator 24, a first mechanism 200 comprises means for measuring the change in distance d1 between a point 202 on the cylinder 82 abutting the frame member 20.1 and a stationary point 204 on the tie rod 34. The change in distance is proportional to the length of the compression spring and therefore to the compression of the compression spring. Using the well-known formula F=Kd1, the change in force exerted by the spring 80 is calculated.

[0043] Referring to FIGS. 13( a ) and 13 ( b ), the change in distance may be measured using proximity switches 302 , 304 , and 306 spaced apart on the tie rod 34 .

Claims

1. 1. A coupling and adjustment system for a furnace including a wall, comprising: a frame located outside the wall, the frame including a plurality of frame members, at least some of the frame members being arranged in pairs across the furnace; a plurality of adjustable spring actuators each including at least one: a) a first adjustable spring actuator configured to apply an adjustable repulsive force between the frame and a wall of the furnace; and b) a second adjustable spring actuator configured to apply an adjustable tension to a tie rod assembly extending between a pair of frame members; a first sensing device associated with one of at least some of the plurality of adjustable spring actuators, the first sensing device having an electronic signal output for providing an output signal indicative of the force exerted by the corresponding adjustable spring actuator; a remote computer controller in signal communication with the electronic signal output and configured to generate data in response to the output signal for use in adjusting the force applied by at least some of the plurality of adjustable spring actuators; the adjustable spring actuator is adjustable by an electromechanical device; 10. A furnace coupling and regulating system, wherein the remote computer controller includes an output device, the remote computer controller configured to provide control signals at the output device derived from the data for controlling the electromechanical device.

2. The furnace coupling and regulating system of claim 1 , wherein each of said plurality of adjustable spring actuators comprises a compression spring.

3. 3. The furnace coupling and regulating system of claim 2, wherein each of the plurality of adjustable spring actuators comprises a cylinder having a first end and a second end, and the compression spring includes an elongated compression spring defining a bore and having a first end and a second end, the elongated compression spring being positioned within the cylinder.

4. 4. The furnace coupling and adjusting system of claim 3, wherein the first adjustable spring actuator includes a first movable piston adjacent a first end of the compression spring and a second movable piston adjacent a second end of the compression spring, the first movable piston extending beyond the first end of the cylinder and terminating in an abutment structure that abuts a wall of the furnace in use, and the second movable piston extending beyond the second end of the cylinder and abutting a first adjustment structure on a first rod directly or indirectly through a first sandwich arrangement of axially movable members, the first sandwich arrangement including a first collar structure directly adjacent the first adjustment structure, and the first adjustment structure being axially adjustable on the first rod to adjust the compression of the compression spring.

5. 5. The furnace coupling and adjusting system of claim 3, wherein the second adjustable spring actuator includes a movable piston defining a hole, the cylinder of the second adjustable spring actuator is mounted on the tie rod assembly with the rod of the assembly passing through the hole in the compression spring and the hole in the movable piston, the movable piston abutting a second adjusting structure directly or indirectly through a second sandwich arrangement of axially movable members, the second sandwich arrangement including a second collar structure directly adjacent to the second adjusting structure, and the second adjusting structure being axially adjustable on the tie rod to adjust the compression of the compression spring.

6. 5. The furnace coupling and regulating system of claim 4, wherein said first regulating structure includes a threaded nut located on a threaded portion of said first rod.

7. A furnace coupling and adjustment system as described in claim 5, wherein the second adjustment structure includes a threaded nut located on the threaded portion of the tie rod.

8. 8. The furnace coupling and adjusting system of claim 6, wherein the nut is manually operable to adjust its axial position.

9. 9. The furnace coupling and adjustment system of claim 8, including a remotely controllable nut release device and a remotely controllable nut manipulation device controlled by said remote computer controller.

10. 10. The furnace coupling and adjusting system of claim 9, wherein the remotely controllable nut release device includes a fluid pressure actuated mechanism for releasing and operating the nut by axially moving an axially movable first collar structure or a second collar structure away from the nut against the bias of the compression spring.

11. 11. The furnace coupling and adjusting system of claim 9, wherein the remotely controllable nut operating device comprises a rotatable structure defining a socket having a suitable shape to receive at least a portion of the nut, and means for rotatably driving the rotatable structure in selectable one of a clockwise direction and a counterclockwise direction.

12. 12. The furnace coupling and regulating system of claim 11, wherein said drive means includes an electric motor and a drive train connected between said rotatable structure and said electric motor.

13. 13. The furnace coupling and regulating system of claim 9, wherein the remote computer controller is configured to, in response to the output signal, generate control signals for controlling the nut release devices of designated ones of the plurality of adjustable spring actuators to release the nuts of those designated actuators and then cause the nut operating devices of those designated actuators to operate the nuts.

14. 7. The furnace coupling and regulating system of claim 4, wherein the first sandwich arrangement includes the sensing device in the form of a first sensing device.

15. A furnace coupling and adjustment system as described in any one of claims 5 and 7, wherein the second sandwich configuration includes the detection device in the form of a first detection device.

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