A monitoring and control structure and method for the expansion amount of a rotary hearth furnace hearth

Abstract

The present invention discloses a structure and method for monitoring and controlling the expansion amount of a rotary hearth furnace bed, which relates to the technical field of rotary hearth furnace monitoring. It solves the problem that when the furnace bed expands to a certain value, it will cause the furnace bottom to deviate, and over time, it will surely exceed the design deviation range, which will lead to serious equipment accidents and even furnace shutdown for maintenance. It includes a foundation, on which a furnace bottom mechanism and a driving device for driving the rotation of the furnace bottom mechanism are connected. Above the furnace bottom mechanism is a furnace bed, and the furnace bed rotates with the furnace bottom mechanism; an induction block is connected to the furnace bed or the furnace bottom mechanism, and a displacement sensor for sensing the displacement of the corresponding induction block is connected to the furnace bottom mechanism or the furnace bed. It can record and reflect the expansion amount of the rotary hearth furnace in real time, achieving the effect of facilitating real-time control adjustment according to the expansion amount.

Description

Technical Field

[0001] The present invention relates to the technical field of rotary hearth furnace monitoring, and particularly to a monitoring and control structure and method for the expansion amount of the hearth of a rotary hearth furnace. Background Art

[0002] At present, new non-blast furnace smelting processes are rapidly developing globally, and the rotary hearth furnace reduction technology is an important part of the new non-blast furnace smelting processes. A rotary hearth furnace is an industrial device in which the furnace top and furnace wall remain stationary during operation, while the furnace bottom rotates along a circular track.

[0003] However, during the operation of the rotary hearth furnace, the temperature rises from normal temperature to 1200 degrees, and the hearth expands due to heat. There are no corresponding devices for displaying, recording, and alarming the monitoring and control of the expansion amount in the existing technology. When the hearth expands to a certain value, it will cause the furnace bottom to deviate, and over time, it will surely exceed the design deviation range, leading to serious equipment accidents and even furnace shutdown and maintenance. Summary of the Invention

[0004] The purpose of the present invention is to provide a monitoring and control structure and method for the expansion amount of the hearth of a rotary hearth furnace, which can record and reflect the expansion amount of the rotary hearth furnace in real time, facilitating real-time control adjustment based on the expansion amount.

[0005] The above technical purpose of the present invention is achieved through the following technical solutions:

[0006] A monitoring and control structure for the expansion amount of the hearth of a rotary hearth furnace includes a foundation, on which a furnace bottom mechanism and a driving device for driving the rotation of the furnace bottom mechanism are connected. Above the furnace bottom mechanism is a hearth, which rotates with the furnace bottom mechanism; an induction block is connected to the hearth or the furnace bottom mechanism, and a displacement sensor for sensing the displacement corresponding to the induction block is connected to the furnace bottom mechanism or the hearth.

[0007] Furthermore, the sensing direction of the displacement sensor is set along the diameter direction of the hearth.

[0008] Furthermore, a plurality of expansion control members are provided at the bottom of the hearth, and corresponding stoppers are connected to the furnace bottom mechanism. The expansion control members hinder the outward expansion of the hearth by pushing against the corresponding stoppers.

[0009] Furthermore, the expansion control member includes a fixed block and an adjusting screw rod. The adjusting screw rod passes through the fixed block, and screw nuts adapted to the adjusting screw rod are fixed at both ends of the fixed block. One end of the adjusting screw rod abuts against the corresponding stopper, and the other end is provided with a power member for driving its rotation.

[0010] Furthermore, the power member includes a servo motor connected to the bottom of the hearth. A large gear is connected to the end of the adjusting screw rod away from the corresponding stopper, and a small gear meshing with the large gear is connected to the output shaft of the servo motor.

[0011] Furthermore, the base includes an inner ring drag wheel and an outer ring drag wheel above, and the bottom machinery of the furnace is supported on the inner ring drag wheel and the outer ring drag wheel.

[0012] Furthermore, the furnace bed is annular, including a number of identical sector bed units. Each bed unit includes a bed frame and a sector plate inside the bed frame. Channel steels are connected to both sides below the bed frame, and the channel steels on the adjacent sides of the adjacent bed frames are fixed by bolts.

[0013] Furthermore, a pointer is connected below the furnace bed, and a scale is connected to the bottom machinery of the furnace. The pointer aligns with the scale graduation to indicate the expansion amount.

[0014] A monitoring and control method for the expansion amount of a rotary hearth furnace bed expansion monitoring and control structure includes the following steps:

[0015] S1: Before the rotary hearth furnace bed operates, first return to zero and then start. When returning to zero, the adjusting screw rod restores to its original position. After starting, the bottom machinery of the furnace rotates under the driving action of the driving device, and the furnace bed thereon follows the rotation of the bottom machinery of the furnace.

[0016] S2: When the temperature of the furnace bed changes, the furnace bed expands radially outward. The displacement sensor senses the displacement distance of the sensing block, and drives the servo motor to rotate according to the displacement distance, controlling the forward or backward movement of the adjusting screw rod to control the expansion amount.

[0017] Furthermore, it also includes step S3: If the displacement sensor senses that the expansion amount exceeds the preset warning value, control an alarm. If it exceeds the preset maximum value, control the rotary hearth furnace to stop operating.

[0018] In summary, the present invention has the following beneficial effects:

[0019] The rotary hearth furnace bed presses on the bottom machinery of the furnace by its own weight. Due to the different temperatures in the heating zones, the furnace bed will freely expand after being heated. A pointer is extended down at the bottom of the furnace bed, and a scale is installed on the bottom machinery of the furnace directly below the pointer. The expansion amount can be intuitively understood on-site, and the displacement amount can also be transmitted in real time through the displacement sensor and fed back to the PLC system.

[0020] When expansion is caused by temperature change, the PLC system will make real-time displacement adjustments to all servo motors according to the expansion amount. When the expansion amount reaches a certain value, an alarm is given or the rotary hearth furnace is stopped from operating. It has the characteristics of reliable operation and high automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the overall structural schematic diagram of the present invention;

[0022] Figure 2 is the structural schematic diagram of the position of some bed units in the present invention;

[0023] Figure 3 is Figure 2 A schematic structural diagram from another perspective;

[0024] Figure 4 is Figure 3 An enlarged structural diagram of part A in

[0025] Figure 5 is Figure 3 An enlarged structural diagram of part B in

[0026] In the figure, 1 is the foundation; 11 is the inner ring drag wheel; 12 is the outer ring drag wheel; 2 is the bottom furnace machinery; 3 is the driving device; 4 is the furnace bed; 41 is the bed frame; 42 is the sector plate; 43 is the channel steel; 5 is the induction block; 51 is the displacement sensor; 6 is the stop block; 61 is the fixed block; 62 is the adjusting screw rod; 64 is the servo motor; 65 is the large gear; 66 is the small gear; 7 is the pointer; 71 is the scale. Specific embodiments

[0027] The following further describes the specific embodiments of the present invention with reference to the accompanying drawings. This embodiment does not constitute a limitation to the present invention.

[0028] A monitoring and control structure for the expansion amount of a rotary hearth furnace bed, as Figure 1 shown, includes a concrete foundation 1. The foundation 1 includes an inner ring drag wheel 11 and an outer ring drag wheel 12 that are fixed above it and are concentrically arranged. A bottom furnace machinery 2 and a driving device 3 for slowly rotating the bottom furnace machinery 2 are connected to the foundation 1;

[0029] Among them, the bottom furnace machinery 2 is supported on the inner ring drag wheel 11 and the outer ring drag wheel 12. A plurality of driving devices 3 are evenly distributed on the outer periphery of the bottom furnace machinery 2. A toothed ring is provided on the outer periphery of the bottom of the bottom furnace machinery 2. The driving device 3 includes a horizontally arranged gear driven by a motor, and the gear meshes with the toothed ring to achieve driving; the motor can also linearly slide along the diameter direction of the bottom furnace machinery 2 through a track and a cylinder to facilitate the meshing or disengagement of the toothed ring and the gear, which is convenient for maintenance or replacement.

[0030] As Figure 1 and Figure 2 shown, a furnace bed 4 is provided above the bottom furnace machinery 2, and the furnace bed 4 rotates with the bottom furnace machinery 2; the spliced furnace bed 4 presses on the bottom furnace machinery 2 by its own weight. Because the frictional force is relatively large, the furnace bed 4 and the bottom furnace machinery 2 can be regarded as a whole and do not relatively slide in the rotation direction;

[0031] The furnace bed 4 is annular and includes a number of identical sector bed units. Each bed unit includes a bed frame 41 and a sector plate 42 inside the bed frame 41. U-shaped channel steels 43 are welded and fixed on both sides below the bed frame 41. The channel steels 43 on the adjacent sides where the bed frames 41 are close to each other are fixed by bolts.

[0032] AsFigure 3 and Figure 4 As shown in Figure 4 , an induction block 5 is connected to the hearth 4 or the bottom machinery 2, and a displacement sensor 51 for sensing the displacement corresponding to the induction block 5 is connected to the bottom machinery 2 or the hearth 4. The sensing direction of the displacement sensor 51 is set along the diameter direction of the hearth 4;

[0033] A pointer 7 is welded and fixed below the hearth frame 41. The induction block 5 is fixed to the side of the pointer 7. The displacement sensor 51 is installed on the side bottom machinery 2 through a fixed buckle. A scale 71 is welded on the bottom machinery 2. The pointer 7 points downward to the scale of the scale 71 to indicate the expansion amount;

[0034] The rotary hearth furnace hearth 4 presses on the bottom machinery 2 by its own weight. Due to the different temperatures in the heating zone, the hearth 4 will expand freely outward along the radial direction after being heated. The pointer 7 moves, and the expansion amount can be intuitively understood on-site through the pointer 7 and the scale 71, while the displacement amount can be transmitted in real time through the induction block 5 and the displacement sensor 51 and fed back to the control module such as the PLC system.

[0035] As Figure 3 and Figure 5 shown, a number of expansion control parts are provided at the inner ring position of the bottom of the hearth 4, and corresponding stoppers 6 are connected to the bottom machinery 2. The expansion control parts hinder the outward expansion of the hearth 4 by pushing against the corresponding stoppers 6;

[0036] The expansion control part includes a fixed block 61 and an adjusting screw rod 62. The adjusting screw rod 62 passes through the fixed block 61. Both ends of the fixed block 61 are fixed with screw nuts adapted to the adjusting screw rod 62. One end of the adjusting screw rod 62 abuts against the corresponding stopper 6, and the other end is provided with a power part for driving its rotation;

[0037] The power part includes a servo motor 64 fixedly connected to the channel steel 43 at the bottom of the hearth 4. One end of the adjusting screw rod 62 away from the corresponding stopper 6 is connected with a large gear 65 through a flat key, and a small gear 66 meshing with the large gear 65 is connected to the output shaft of the servo motor 64.

[0038] The monitoring and control method of the above monitoring and control structure includes the following steps,

[0039] S1: Before the rotary hearth furnace hearth 4 runs, first return to zero and then start. When returning to zero, the adjusting screw rod 62 returns to its original position. After starting, the bottom machinery 2 rotates under the driving action of the driving device 3, and the hearth 4 thereon follows the bottom machinery 2 to rotate;

[0040] S2: When the temperature of the hearth 4 changes, the hearth 4 expands radially outwards. The displacement sensor 51 senses the displacement distance of the induction block 5 and transmits the displacement quantity to the PLC system. The PLC system drives the servo motor 64 to rotate according to the displacement distance (real-time change of expansion), controls the regulating screw 62 to advance or retreat, and makes real-time displacement adjustment to control the expansion amount (several servo motors 64 are installed around the whole rotary hearth furnace to make the hearth 4 expand evenly);

[0041] Under the above normal operation conditions, the PLC transmits the displacement quantity to the main control computer in real time, and intuitively records the change of the expansion amount by displaying the displacement trend graph and other means on the computer screen, which is convenient to prevent possible accidents from the trend;

[0042] S3: If the displacement sensor 51 senses that the expansion amount exceeds the preset warning value, it controls an alarm (the alarm sounds or the operation screen flashes, etc. to give an alarm). If it exceeds the preset maximum value, it controls the rotary hearth furnace to stop running.

[0043] The present invention can record and reflect the expansion amount of the rotary hearth furnace in real time, make real-time control adjustments according to the expansion amount, and has the functions of alarm reminder and stop running. The movement trajectory is displayed in real time on the computer, and has the characteristics of reliable operation and high automation degree.

[0044] The above is only a preferred embodiment of the present invention and is not used to limit the present invention. Those skilled in the art can make various modifications or equivalent replacements to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the technical solution of the present invention.

Claims

1. A monitoring and control structure for the expansion amount of a rotary hearth furnace hearth, characterized in that: It includes a base, on which a bottom furnace mechanism and a driving device for driving the bottom furnace mechanism to rotate are connected. Above the bottom furnace mechanism, there is a hearth, and the hearth rotates following the bottom furnace mechanism; an induction block is connected to the hearth or the bottom furnace mechanism, and a displacement sensor for sensing the displacement of the corresponding induction block is connected to the bottom furnace mechanism or the hearth. A number of expansion control components are provided at the bottom of the hearth, and corresponding stoppers are connected to the bottom furnace mechanism. The expansion control components prevent the outward expansion of the hearth by pushing against the corresponding stoppers; the expansion control components include a fixed block and an adjusting screw rod. The adjusting screw rod passes through the fixed block, and screw nuts adapted to the adjusting screw rod are fixed at both ends of the fixed block. One end of the adjusting screw rod abuts against the corresponding stopper, and a power component for driving its rotation is provided at the other end; the power component includes a servo motor connected to the bottom of the hearth. A large gear is connected to the end of the adjusting screw rod away from the corresponding stopper, and a small gear meshing with the large gear is connected to the output shaft of the servo motor.

2. The monitoring and control structure for the expansion amount of the rotary hearth furnace hearth according to claim 1, characterized in that: The sensing direction of the displacement sensor is set along the diameter direction of the hearth.

3. The monitoring and control structure for the expansion amount of the rotary hearth furnace hearth according to claim 1, characterized in that: The base includes an inner ring idler and an outer ring idler above, and the bottom furnace mechanism is supported on the inner ring idler and the outer ring idler.

4. A monitoring and control structure for the expansion amount of a rotary hearth furnace hearth according to claim 1, characterized in that: The hearth is annular and includes a number of identical sector-shaped bed units. Each bed unit includes a bed frame and a sector plate within the bed frame. Channel steels are connected to both sides below the bed frame, and the channel steels on the adjacent bed frames close to each other are fixed by bolts.

5. The monitoring and control structure for the expansion amount of the rotary hearth furnace bed according to claim 1 or 4, characterized in that: A pointer is connected below the hearth, and a scale is connected to the bottom furnace mechanism. The pointer aligns with the scale graduation to indicate the expansion amount.

6. A monitoring and control method for the monitoring and control structure of the rotary hearth furnace bed expansion amount according to claim 1, characterized in that: It includes the following steps. S1: Before the rotary hearth furnace hearth operates, first return to zero and then start. When returning to zero, the adjusting screw rod returns to its original position. After starting, the bottom furnace mechanism rotates under the driving action of the driving device, and the hearth thereon rotates following the bottom furnace mechanism. S2: When the temperature of the hearth changes, the hearth expands radially outward. The displacement sensor senses the displacement distance of the induction block and drives the servo motor to rotate according to the displacement distance, controlling the forward or backward movement of the adjusting screw rod to control the expansion amount.

7. A monitoring and control method according to claim 6, characterized in that: It further includes step S3: If the displacement sensor senses that the expansion amount exceeds a preset warning value, control an alarm. If it exceeds a preset maximum value, control the rotary hearth furnace to stop operating.

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