EP2761242B1 - Auto-adjusting binding system for metallurgical furnace - Google Patents
Auto-adjusting binding system for metallurgical furnace Download PDFInfo
- Publication number
- EP2761242B1 EP2761242B1 EP12835429.7A EP12835429A EP2761242B1 EP 2761242 B1 EP2761242 B1 EP 2761242B1 EP 12835429 A EP12835429 A EP 12835429A EP 2761242 B1 EP2761242 B1 EP 2761242B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- load
- furnace
- binding
- auto
- adjusting device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000027455 binding Effects 0.000 title claims description 85
- 238000009739 binding Methods 0.000 title claims description 85
- 238000000034 method Methods 0.000 claims description 10
- 230000007246 mechanism Effects 0.000 claims description 5
- 238000005259 measurement Methods 0.000 claims description 2
- 239000007789 gas Substances 0.000 description 16
- 230000003247 decreasing effect Effects 0.000 description 9
- 239000011449 brick Substances 0.000 description 8
- 230000006835 compression Effects 0.000 description 8
- 238000007906 compression Methods 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 238000003723 Smelting Methods 0.000 description 5
- 239000012530 fluid Substances 0.000 description 5
- 239000011819 refractory material Substances 0.000 description 5
- 230000033001 locomotion Effects 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 3
- 230000008602 contraction Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000001351 cycling effect Effects 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000009856 non-ferrous metallurgy Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000013641 positive control Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005382 thermal cycling Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
- F27B3/08—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces heated electrically, with or without any other source of heat
- F27B3/085—Arc furnaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
- F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
- F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
- F27B3/28—Arrangement of controlling, monitoring, alarm or the like devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D19/00—Arrangements of controlling devices
Definitions
- the present subject matter relates to furnaces constructed of hearth and sidewall refractories, and more particularly relates to systems for the compressive binding of these refractories.
- Furnaces are used extensively in the smelting and converting of ferrous and non-ferrous ores and concentrates.
- Furnaces of this type are generally circular or rectangular, having a bottom wall (hearth) and vertical walls comprised of refractory bricks and a roof or off gas hood. These furnaces are also characterized by a binding and support structure, the purpose of which is to maintain the refractory bricks of the hearth and walls in compression.
- Adequate compression of the furnace walls, and particularly the hearth, is critical to maximize furnace campaign life and to prevent costly and potentially catastrophic furnace failure.
- the individual bricks comprising the hearth and the walls expand, resulting in outward expansion of the hearth.
- cooling of the furnace results in contraction of the individual bricks and overall shrinking of the furnace. If the compressive forces on the hearth or the walls are insufficient, gaps will be formed between the bricks during cooling phases of the furnace operation. These gaps can be infiltrated with molten metal or other material, resulting in permanent growth of the furnace, or in the worst case, catastrophic failure of the refractory with a resulting run out of the furnace contents.
- the binding system usually consists of regularly spaced vertical beams known as "buckstays", which are held together at the top and bottom by horizontal tie members extending across the furnace, the bottom tie members passing beneath the hearth and the upper tie members passing above the furnace roof.
- buckstays regularly spaced vertical beams known as "buckstays"
- the structure of electric furnaces is discussed in more detail in Francki et al., Design of refractories and bindings for modem high-productivity pyrometallurgical furnaces, Non-Ferrous Metallurgy, Vol. 86, No. 971, pp. 112 to 118 .
- Frequent adjustment of the tie members, as by loosening or tightening retaining nuts at the tie member ends, is necessary to maintain relatively constant compression on the refractories during thermal cycling of the furnace.
- the binding systems of most large rectangular furnaces in operation today are equipped with compression spring sets sized to maintain the desired compression on the brick work, thereby permitting some expansion and contraction of the furnace while maintaining the hearth
- spring sets permit some furnace movement, they do not eliminate the need for periodic adjustment of the spring loads to ensure that the forces on the tie members and the furnace hearth remain relatively constant during use of the furnace. Adjustment of the spring loads is performed with hydraulic jacking equipment, and is a difficult and unpleasant operation due the fact that the vicinity of the furnace is usually hot, dirty and ill-lit and because the adjustment screws on the spring sets usually become more difficult to turn with time. Therefore, the frequency of adjustment tends to be low and spring binding systems are often not used to their full advantage.
- US 3,869,996 discloses a method for the positive control of mechanical stresses in a roof during "cold” and “hot” periods in the furnace operation by applying variable distributed loads directed opposite and according to the force of gravity to the roof surface and variable bending moments to the roof edges. It also discloses a device comprising means disposed on the furnace roof and framework and adapted for applying said variable distributed loads to the roof surface and variable bending moments to the roof edges resting on skewbacks.
- an auto-adjusting device for a binding system of a metallurgical furnace.
- the auto-adjusting device comprises a gauge or sensor that constantly or intermittently measures one of either the furnace binding forces or the pressure of an associated hydraulic system.
- a load adjustment mechanism responsive to a measurement by the gauge or sensor that exceeds a predetermined amount either above or below the desired load, then automatically adjusts the load of the binding system.
- the load adjustment mechanism comprises a hydraulic motor and a gear train, said gear train comprising a gear nut.
- the auto-adjusting device for a binding system for a metallurgical furnace further comprises a load cell that measures the furnace binding forces and determines when the load varies by more than a pre-defined limit from a set point; and a hub and a hydraulic cylinder in series with the hydraulic motor and gear train.
- a method of operation of an auto-adjusting device of the invention is also provided, which comprises the following steps:
- the auto-adjusting device includes a gear train.
- the device includes two hydraulic cylinders installed in series.
- Yet other embodiments include a worm drive and motor. Such embodiments can be used with or without springs to reduce the frequency of the required adjustments.
- a sensor can be utilized to measure the total movement of each buckstay at the top and bottom.
- the auto-adjusting device is able to maintain the plumbness of the buckstays ensuring the appropriate load is applied along the length of the buckstay.
- the present subject matter overcomes the problems of the prior art by providing a furnace binding and adjustment system in which the compressive forces on the furnace hearth can be accurately controlled and monitored on a continuous basis.
- the present subject matter avoids continuous reliance on an applied hydraulic load. As a result, a leak of the hydraulic system does not result in a loss of the load on the binding system. Moreover, avoiding reliance on a hydraulic system that remains static under a high load for a long period helps to avoid having seals become set.
- the present subject matter can automate the binding adjustment procedure for all forms of furnace bindings; primary and secondary hearth bindings, horizontal wall bindings, vertical wall hold down binding, and circular shell bindings.
- the apparatus is intended to apply the specified design binding loads to the furnace refractory through all phases of the furnace operation without requiring regular manual adjustment.
- the proposed apparatus can be applied to new smelting furnaces being built or retrofitted to improve existing smelting furnaces.
- the proposed apparatus can be applied to furnaces with a large number of binding load points or furnaces with as little as one binding system.
- FIGS 1 to 3 illustrate the basic structure of a typical rectangular electric furnace 10 to which the auto-adjustment binding system of the present subject matter is applied.
- the cross-section of Fig. 1 is taken transverse to the longitudinal axis of the furnace.
- Furnace 10 comprises a pair of opposed sidewalls 12 and 14, a pair of opposed end walls 16 and 18 ( Fig. 2 ), a hearth 20, an arched roof 22, and a plurality of electrodes 24 spaced along the longitudinal axis of the furnace 10.
- the hearth 20, as well as the sidewalls 12, 14 and end walls 16, 18 are constructed of refractory brick in a known manner.
- the refractory bricks of the hearth and the side and end walls are maintained in compression by vertical metal shell plates 19 which are contained by flexible bindings comprised of regularly-spaced vertical buckstays 30 held together at the top and bottom by horizontal tie members 32, 33.
- each buckstay 30 is arranged in regular, spaced relation around the side and end walls of the furnace 10.
- Each buckstay comprises a vertical steel beam having a lower end 34 extending below the hearth 20 and the furnace bottom and an upper end 36 extending above the tops of the furnace walls 12, 14, 16, 18 and the furnace roof 22.
- the buckstays 30 are arranged in pairs, with the buckstays of each pair being positioned on opposite sides of the furnace. In Fig. 3 , the buckstays of each pair are in opposed relation to one another directly across the furnace from one another.
- the buckstays 30 of each pair are connected at their upper ends 36 by at least one upper tie member 32 and at their lower ends 34 by at least one lower tie member 33.
- the upper ends 36 of each pair of buckstays 30 are connected by a single upper tie member 32
- the lower ends 34 of each pair of buckstays 30 are connected by a single lower tie member 33. It will be appreciated that the expansive forces are greatest at the lower ends 34 of buckstays 30 due to expansion of the hearth 20, and therefore it may be preferred to connect the lower ends 34 of each pair of buckstays 30 with two or more lower tie members 33.
- the furnace binding and adjustment system further comprises a plurality of fluid-pressurized tensioning means 40 provided at the ends of tie members 32, 33, the tensioning means 40 being adjustable so as to permit lateral expansion and contraction of the furnace 10 while applying compressive forces to the hearth, sidewall and end wall refractories through the buckstays 30.
- a tensioning means 40 is preferably provided at a first end of each lower tie member 33. In some cases, a tensioning means may be provided on both sides.
- each upper tie member 32 extending between the end walls 16, 18 may preferably be provided with a tensioning means at one of its ends.
- the fluid pressure in the tensioning means 40 is regulated by pressure regulating means, generally identified by reference numeral 99 in the drawings.
- pressure regulation means 99 are provided for each of the tensioning means 40 and the motors 7, thereby permitting the fluid pressure of both the tensioning means 40 and the motor 7 to be regulated simultaneously or individually.
- the tensioning means 40 and motor 7 are powered by a hydraulic power unit (HPU) 97. Both the pressure regulation 99 and the HPU 97 may be located remotely relative to the furnace 10.
- the system further comprises a means for controlling the operation of the adjustment system.
- Control means 101 are schematically shown in Fig. 1 as the means by which the HPU 97 and pressure regulation 99 are controlled. As shown, control means 101 are operated from a control room 103, schematically shown in Fig. 1 , which may be remotely located relative to the furnace 10.
- the system further comprises optional displacement sensors 122 located at the top and bottom of each buckstay.
- the sensors measure the buckstay movement relative to its starting position and fed back to a control room 103, schematically shown in Fig. 1 , which may be remotely located relative to the furnace 10. Data interpretation is fed back through the control means 101 to operate the tensioning means 40 when it is determined that the buckstay plumbness is outside of allowable limits.
- an auto tensioning device is shown. It can be described as having vertical components including a hydraulic motor and a gear train in which the last gear is made of a gear and a nut joined together, and horizontal components including a hub and a hydraulic cylinder in series.
- a load cell or cells 121 are used to determine the load within the system.
- the system can be connected directly to a tie rod, or use a set of springs to assist with regulating the load and to decrease the frequency of the adjustments.
- the basic principle of operation is the load cell measures the furnace binding forces and determines when the load varies by more than the predefined limit from the set point indicating that the system requires adjustment.
- the hydraulic cylinder When it has been determined that the binding load requires adjustment, the hydraulic cylinder is engaged and set to exceed the load being applied in order to off-load the gear nut. The hydraulic motor is then engaged to set the gear nut back with a preset number of revolutions. The hydraulic cylinder sets the binding load to the design load. The hydraulic motor is engaged to set the gear nut back into contact with the bearing plate. The hydraulic cylinder is unloaded and the load cell or cells check to ensure the proper load is being applied to the system.
- a load cell or cells are installed within the system to give feedback of binding load and adjustment will take place once the load deviates from the predefined upper or lower limit.
- One possible configuration is shown in Fig. 6 where the load cells are placed on the unsprung end of the tie rod 33. If the load cell malfunctions or is not calibrated properly the hydraulic jack can be utilized to determine the load within the system.
- the cylinder 1 will be activated to unload the gear nut 3.
- a hub 2 transmits the force from the hydraulic cylinder 1 to the binding plate 11 while allowing the gear nut 3 to rotate.
- the motor 7 will be engaged in order to rotate the pinion 5 which is mounted directly on the shaft of the motor 7.
- the purpose of the pinion 5 is to transmit the rotational power of the motor 7 to the gear nut 3. Due to space requirements, in some instances an idle gear 4 will be installed between the pinion 5 and the gear nut 3. Its purpose is only to transmit the motion between the two.
- a gear set cover 6 protects the gear train against dirt and dust and also provides a reaction force acting opposite the rotational force of the motor 7.
- the motor 7 is engaged such that the gear nut 3 will be rotated away from the binding plate 11 allowing room for the cylinder to adjust the binding load.
- the load in the hydraulic cylinder 1 will be set to match the design force thereby restoring the proper load to the system.
- the motor 7 rotates the gear nut 3 back until it makes contact with the binding plate 11.
- the gear nut 3 stops rotating the remaining pressure is released from the hydraulic circuit and the system comes to rest.
- the frequency of these actions will depend on the furnace operation and the frequency of adjustment can be reduced by installing compressions springs 9 within the system.
- the hydraulic cylinder 1 is installed close to its fully extended position during the initial installation. Over time this extension will compensate for the expansion of the furnace 10. As the furnace grows the cylinder 1 will get shorter. It is worth noting that the estimated expansion of the furnace should correspond to the length of the stroke of the hydraulic cylinder 1 to prevent having to reset the hydraulic system prior to the furnace end of life.
- the gear nut 3 serves a dual purpose; during normal operation the gear nut 3 transfers the binding load between the tie rod 33 and the binding plate 11. During the self-adjusting period the gear nut 3 is disengaged and the gear is used to move the gear nut 3 back and forth in order to keep the load on the tie rod 33 constant.
- a hydraulic cylinder saddle 8 can be utilized to support the weight of the cylinder 1 while the cylinder 1 is unloaded.
- An alternative arrangement of a similar embodiment utilizes a sprocket and chain in place of the gear train to transfer the motor rotation to the nut.
- the verticality, or plumbness, of the buckstays will be monitored to ensure that the buckstays remain plumb within a certain predefined distance. If the buckstays exceed the allowable out-of-plumbness the hydraulic motors and jacks will be utilized as described above to re-plumb the buckstays.
- This method eliminates the need for a manual check and adjustment of the binding loads.
- FIG. 7 and 8 a second embodiment of an auto-tensioning device is shown. It can be described as made of two hollow jacks in series coupled with accumulators and an associated gas (nitrogen, air, or other) supply system. Based on the pressure applied by the furnace on the jacks a PLC controls the pressure on the accumulator increasing or decreasing it based on the design load.
- gas nitrogen, air, or other
- the basic principle of operation is the two hydraulic cylinders 21 are installed in series close to their fully extended position. Over time this extension will compensate for the expansion of the furnace 10. As the furnace 10 grows, the cylinder will get shorter.
- the back-to-back cylinders 21 provide two important functions: 1) allowing the cylinders to cycle through their stroke while maintaining a constant load on the furnace and 2) redundancy, in the event that one hydraulic cylinder fails, the second will maintain the design load.
- the hydraulic cylinders 21 apply the design load to the furnace through a tie rod 32 or 33.
- a pressure gauge measures the pressure within the accumulator 29 and determines if the pressure varies from the design pressure by more than the predefined limit which would indicate that the system requires adjustment.
- the accumulator 29 acts as a spring, as the furnace expands and contracts, the gas within the accumulator is compressed and expands.
- a valve adds additional gas to the system through the gas supply line 25 to increase the load and a relief valve releases gas to decrease the load within the system.
- a non-flammable hydraulic fluid is supplied to the hydraulic cylinders 21 through the hydraulic supply line attached to the accumulator 29. Rubber bellows 26 are positioned at either end of the hydraulic cylinder to seal and protect the internal components from heat and dust contamination.
- An isolation nut 23 is included and serves two purposes: 1) it can be tightened thereby removing load from the hydraulic system while maintaining load on the buckstay allowing the system to be serviced or replaced with the load removed; or 2) it acts as a mechanical failsafe in the event that there is a failure of the hydraulic system.
- a standoff 28 offsets the hydraulic binding system away from the furnace to allow space for the isolation nut 23.
- each accumulator 29 The gas pressure within each accumulator 29 is monitored through pressure gauges and the data fed back to the PLC which equates the pressure to an applied load. The load will be monitored to determine if it deviates from the prescribed load range.
- the hydraulic system has three modes of adjustment; decreasing binding load, increasing binding load, and cycling the jacks to ensure all seals are properly lubricated and to prevent seizure. The three modes of adjustment are described below.
- the gas pressure within the accumulator 29 is allowed to increase up to a set maximum pressure. As the pressure increases within the accumulator 29 it acts as a spring buffering the load applied to the furnace.
- the gas pressure within the accumulator is allowed to decrease down to a set minimum pressure. As the pressure is decreases within the accumulator it is acting as a spring maintaining load onto the furnace.
- the cylinders Periodically the cylinders are cycled in order to ensure the seals are properly lubricated and the cylinders do not seize.
- the binding load is to be maintained within the defined load range throughout the cycling operation.
- One of the two accumulators decreases the pressure by releasing gas through the relief valve. Gas is added to the second accumulator to accommodate the decreased pressure from the first. This method, while decreasing the stroke of one cylinder, increases the stroke of the second cylinder to match through a series of small steps to ensure proper binding loads are maintained throughout the process.
- the two cylinders then return to their starting position such that the two cylinders each have the same stroke.
- the third embodiment of an auto-adjusting device is shown in Figure 9 . It can be likened to a screw jack powered by a hydraulic or electric motor.
- the basic principle of operation is the binding load on each tie rod will be monitored through load cells 121 and the data fed back to the PCP.
- the load is monitored to determine if it deviates from the prescribed load range.
- the motor 7 turns the worm 113 which in turn rotates the worm gear 112.
- the binding load can be increased or decreased dependent upon the direction of rotation of the motor 7.
- a load bearing 111 is included to take both the vertical and horizontal loads.
- a housing 114 and a housing cap 110 protect the worm drive and associated hardware from dirt and dust.
- a spring 9 can be utilized to reduce the frequency of adjustment.
- the worm drive can be custom designed or utilize an existing screw jack design depending on the load and space requirements.
- the verticality, or plumbness, of the buckstays will be monitored to ensure that the buckstays remain plumb within a certain predefined distance. If the buckstays exceed the allowable out-of-plumbness, the hydraulic motors and jacks will be utilized as described above will be utilized to re-plumb the buckstays.
- the present subject matter can thus automate the binding adjustment procedure for all forms of furnace bindings; primary and secondary hearth bindings, horizontal wall bindings, vertical wall hold down binding, and circular shell bindings.
- the apparatus is intended to apply the specified design binding loads to the furnace refractory through all phases of the furnace operation without requiring regular manual adjustment.
- the hydraulic systems can be used with or without binding springs.
- the proposed apparatus can be applied to new smelting furnaces being built or retrofitted to improve existing smelting furnaces.
- the proposed apparatus can be applied to furnaces with a large number of binding load points or furnaces with as little as one binding system.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
Description
- The present subject matter relates to furnaces constructed of hearth and sidewall refractories, and more particularly relates to systems for the compressive binding of these refractories.
- Furnaces are used extensively in the smelting and converting of ferrous and non-ferrous ores and concentrates. Furnaces of this type are generally circular or rectangular, having a bottom wall (hearth) and vertical walls comprised of refractory bricks and a roof or off gas hood. These furnaces are also characterized by a binding and support structure, the purpose of which is to maintain the refractory bricks of the hearth and walls in compression.
- Adequate compression of the furnace walls, and particularly the hearth, is critical to maximize furnace campaign life and to prevent costly and potentially catastrophic furnace failure. During heating of the furnace to operating temperature, the individual bricks comprising the hearth and the walls expand, resulting in outward expansion of the hearth. Conversely, cooling of the furnace results in contraction of the individual bricks and overall shrinking of the furnace. If the compressive forces on the hearth or the walls are insufficient, gaps will be formed between the bricks during cooling phases of the furnace operation. These gaps can be infiltrated with molten metal or other material, resulting in permanent growth of the furnace, or in the worst case, catastrophic failure of the refractory with a resulting run out of the furnace contents. Repetition of heating and cooling cycles results in further incremental expansion of the furnace (known as "ratcheting"), which usually results in a reduction of the furnace campaign life, by the potential for molten infiltration into the hearth refractory or excessive expansive forces exerted on the binding system.
- In rectangular furnaces, the binding system usually consists of regularly spaced vertical beams known as "buckstays", which are held together at the top and bottom by horizontal tie members extending across the furnace, the bottom tie members passing beneath the hearth and the upper tie members passing above the furnace roof. The structure of electric furnaces is discussed in more detail in Francki et al., Design of refractories and bindings for modem high-productivity pyrometallurgical furnaces, Non-Ferrous Metallurgy, Vol. 86, No. 971, pp. 112 to 118. Frequent adjustment of the tie members, as by loosening or tightening retaining nuts at the tie member ends, is necessary to maintain relatively constant compression on the refractories during thermal cycling of the furnace. The binding systems of most large rectangular furnaces in operation today are equipped with compression spring sets sized to maintain the desired compression on the brick work, thereby permitting some expansion and contraction of the furnace while maintaining the hearth under compression.
- While spring sets permit some furnace movement, they do not eliminate the need for periodic adjustment of the spring loads to ensure that the forces on the tie members and the furnace hearth remain relatively constant during use of the furnace. Adjustment of the spring loads is performed with hydraulic jacking equipment, and is a difficult and unpleasant operation due the fact that the vicinity of the furnace is usually hot, dirty and ill-lit and because the adjustment screws on the spring sets usually become more difficult to turn with time. Therefore, the frequency of adjustment tends to be low and spring binding systems are often not used to their full advantage.
- The problems with prior art adjustment systems are exemplified by
US20040069192 A1 15 april 2004 orU.S. Pat. No. 3,197,385 (Wethly), issued on Jul. 27, 1965 . This patent relates to the use of hydraulic jacking equipment for adjustment of tie rod tension in a coke oven battery. According to Wethly, the tension in each tie rod is adjusted by a hydraulic tensioning jack which is mounted on the ends of the rods. However, the tensioning jack must be sequentially mounted on each tension rod to adjust the tension in the rods one by one, in sequence. In the sequential adjustment system taught by Wethly, it would be difficult to control the tension in the rods with any degree of precision since adjusting the tension in one rod will have an effect on the tension in neighboring rods. Furthermore, the sequential mounting and use of a hydraulic jack in close proximity to the furnace is an unpleasant task which is likely to be performed only when absolutely necessary, and therefore the frequency of adjustment is likely to be low. -
US 3,869,996 , referred to "Method and apparatus for extending life period of furnace roofs", discloses a method for the positive control of mechanical stresses in a roof during "cold" and "hot" periods in the furnace operation by applying variable distributed loads directed opposite and according to the force of gravity to the roof surface and variable bending moments to the roof edges. It also discloses a device comprising means disposed on the furnace roof and framework and adapted for applying said variable distributed loads to the roof surface and variable bending moments to the roof edges resting on skewbacks. - Therefore, a need exists for improved furnace binding systems for both rectangular and circular furnaces. Preferably, such systems would permit the compressive forces on the refractory hearth and furnace walls to be accurately adjusted, and would permit adjustment of the compressive forces to be carried out remotely and continuously, thereby maximizing furnace life and improving safety. Additionally, in the case of rectangular furnaces, it is beneficial to maintain the verticality (plumbness) of the buckstays during operation to ensure that the binding load is delivered to the appropriate locations along the furnace wall. A buckstay that is out-of-plumb can redistribute the binding load along the length of the buckstay and has the potential to unload the furnace hearth which could lead to a run out.
- The following summary is intended to introduce the reader to the more detailed description that follows and not to define or limit the claimed subject matter.
- In accordance with the present subject matter, an auto-adjusting device is provided for a binding system of a metallurgical furnace. The auto-adjusting device comprises a gauge or sensor that constantly or intermittently measures one of either the furnace binding forces or the pressure of an associated hydraulic system. A load adjustment mechanism responsive to a measurement by the gauge or sensor that exceeds a predetermined amount either above or below the desired load, then automatically adjusts the load of the binding system. The load adjustment mechanism comprises a hydraulic motor and a gear train, said gear train comprising a gear nut. The auto-adjusting device for a binding system for a metallurgical furnace further comprises a load cell that measures the furnace binding forces and determines when the load varies by more than a pre-defined limit from a set point; and a hub and a hydraulic cylinder in series with the hydraulic motor and gear train.
- A method of operation of an auto-adjusting device of the invention is also provided, which comprises the following steps:
- the load cell measures the furnace binding forces and determines when the load varies by more than a pre-defined limit from the set point indicating that the system requires adjustment,
- when it has been determined that the binding load requires adjustment, the hydraulic cylinder is engaged and set to exceed the load being applied in order to off-load the gear nut,
- the hydraulic motor is engaged to set the gear nut back with a preset number of revolutions,
- the hydraulic cylinder sets the binding load to the design load,
- the hydraulic motor is engaged to set the gear nut back into contact with a bearing plate,
- the hydraulic cylinder is unloaded and the load cell or cells check to ensure the proper load is being applied to the system.
- In some embodiments, the auto-adjusting device includes a gear train. In other embodiments, the device includes two hydraulic cylinders installed in series. Yet other embodiments include a worm drive and motor. Such embodiments can be used with or without springs to reduce the frequency of the required adjustments.
- In addition to maintaining the binding loads within a preset limit, a sensor can be utilized to measure the total movement of each buckstay at the top and bottom. The auto-adjusting device is able to maintain the plumbness of the buckstays ensuring the appropriate load is applied along the length of the buckstay.
- The present subject matter overcomes the problems of the prior art by providing a furnace binding and adjustment system in which the compressive forces on the furnace hearth can be accurately controlled and monitored on a continuous basis. The present subject matter avoids continuous reliance on an applied hydraulic load. As a result, a leak of the hydraulic system does not result in a loss of the load on the binding system. Moreover, avoiding reliance on a hydraulic system that remains static under a high load for a long period helps to avoid having seals become set.
- The present subject matter can automate the binding adjustment procedure for all forms of furnace bindings; primary and secondary hearth bindings, horizontal wall bindings, vertical wall hold down binding, and circular shell bindings. Specifically, the apparatus is intended to apply the specified design binding loads to the furnace refractory through all phases of the furnace operation without requiring regular manual adjustment.
- The proposed apparatus can be applied to new smelting furnaces being built or retrofitted to improve existing smelting furnaces. The proposed apparatus can be applied to furnaces with a large number of binding load points or furnaces with as little as one binding system.
- The subject matter will now be described, by way of example only, with reference to the accompanying drawings, in which:
-
Fig. 1 is an end view, partly in cross-section, of an electric furnace incorporating a furnace binding and adjustment system according to a first preferred embodiment of the present subject matter; -
Fig. 2 is a side view, partly in cross-section, of the furnace shown inFig. 1 ; -
Fig. 3 is a plan view, showing in isolation the buckstays, tie members and fluid-pressurized tensioning means in the lower portion of the furnace shown inFig. 1 ; -
Fig. 4 is an isometric cut away view of an auto-adjusting device for a binding system of a metallurgical furnace according to a first embodiment; -
Fig. 5 is an isometric view showing the exterior of the device; -
Fig. 6 is an isometric view of the load cells shown on the unsprung end of the tie rod portion of the same device; -
Fig. 7 is an isometric view of an auto-adjusting device for a binding system of a metallurgical furnace according to a second embodiment; -
Fig. 8 is a cross sectional view of a portion of the same device. -
Fig. 9 is a cross sectional view of an auto-adjusting device for a binding system of a metallurgical furnace according to a third embodiment. -
Figures 1 to 3 illustrate the basic structure of a typical rectangular electric furnace 10 to which the auto-adjustment binding system of the present subject matter is applied. The cross-section ofFig. 1 is taken transverse to the longitudinal axis of the furnace. Furnace 10 comprises a pair ofopposed sidewalls opposed end walls 16 and 18 (Fig. 2 ), ahearth 20, anarched roof 22, and a plurality ofelectrodes 24 spaced along the longitudinal axis of the furnace 10. - The
hearth 20, as well as thesidewalls walls metal shell plates 19 which are contained by flexible bindings comprised of regularly-spacedvertical buckstays 30 held together at the top and bottom byhorizontal tie members - As best shown in
Fig. 3 , thebuckstays 30 are arranged in regular, spaced relation around the side and end walls of the furnace 10. Each buckstay comprises a vertical steel beam having alower end 34 extending below thehearth 20 and the furnace bottom and anupper end 36 extending above the tops of thefurnace walls furnace roof 22. - The
buckstays 30 are arranged in pairs, with the buckstays of each pair being positioned on opposite sides of the furnace. InFig. 3 , the buckstays of each pair are in opposed relation to one another directly across the furnace from one another. - The
buckstays 30 of each pair are connected at their upper ends 36 by at least oneupper tie member 32 and at their lower ends 34 by at least onelower tie member 33. In the preferred embodiment shown in the drawings, the upper ends 36 of each pair ofbuckstays 30 are connected by a singleupper tie member 32, and the lower ends 34 of each pair ofbuckstays 30 are connected by a singlelower tie member 33. It will be appreciated that the expansive forces are greatest at the lower ends 34 ofbuckstays 30 due to expansion of thehearth 20, and therefore it may be preferred to connect the lower ends 34 of each pair ofbuckstays 30 with two or morelower tie members 33. - As shown throughout the drawings, the upper ends 36 and lower ends 34 of
buckstays 30 are apertured to permit the ends of thetie members tie members buckstays 30. - At the lower ends of
buckstays 30, shown inFig. 3 , a tensioning means 40 is preferably provided at a first end of eachlower tie member 33. In some cases, a tensioning means may be provided on both sides. - Similarly, a plurality of tensioning means 40 are provided at the ends of the
upper tie members 32. However, thetie members 32 extending across the central portions of theside walls end walls side walls upper tie member 32 extending between theend walls - The fluid pressure in the tensioning means 40 is regulated by pressure regulating means, generally identified by
reference numeral 99 in the drawings. In the preferred embodiment of the invention, pressure regulation means 99 are provided for each of the tensioning means 40 and themotors 7, thereby permitting the fluid pressure of both the tensioning means 40 and themotor 7 to be regulated simultaneously or individually. The tensioning means 40 andmotor 7 are powered by a hydraulic power unit (HPU) 97. Both thepressure regulation 99 and theHPU 97 may be located remotely relative to the furnace 10. - The system further comprises a means for controlling the operation of the adjustment system. Control means 101 are schematically shown in
Fig. 1 as the means by which theHPU 97 andpressure regulation 99 are controlled. As shown, control means 101 are operated from acontrol room 103, schematically shown inFig. 1 , which may be remotely located relative to the furnace 10. - The system further comprises
optional displacement sensors 122 located at the top and bottom of each buckstay. The sensors measure the buckstay movement relative to its starting position and fed back to acontrol room 103, schematically shown inFig. 1 , which may be remotely located relative to the furnace 10. Data interpretation is fed back through the control means 101 to operate the tensioning means 40 when it is determined that the buckstay plumbness is outside of allowable limits. - Turning to
Figures 4 to 6 , one embodiment of an auto tensioning device is shown. It can be described as having vertical components including a hydraulic motor and a gear train in which the last gear is made of a gear and a nut joined together, and horizontal components including a hub and a hydraulic cylinder in series. A load cell orcells 121 are used to determine the load within the system. The system can be connected directly to a tie rod, or use a set of springs to assist with regulating the load and to decrease the frequency of the adjustments. The basic principle of operation is the load cell measures the furnace binding forces and determines when the load varies by more than the predefined limit from the set point indicating that the system requires adjustment. When it has been determined that the binding load requires adjustment, the hydraulic cylinder is engaged and set to exceed the load being applied in order to off-load the gear nut. The hydraulic motor is then engaged to set the gear nut back with a preset number of revolutions. The hydraulic cylinder sets the binding load to the design load. The hydraulic motor is engaged to set the gear nut back into contact with the bearing plate. The hydraulic cylinder is unloaded and the load cell or cells check to ensure the proper load is being applied to the system. - In locations requiring small loads a variation of the above can be utilized which does not include the hydraulic cylinder. Instead the hydraulic motor is designed as a power screw and is able to turn the gear nut while the nut is still under load.
- A load cell or cells are installed within the system to give feedback of binding load and adjustment will take place once the load deviates from the predefined upper or lower limit. One possible configuration is shown in
Fig. 6 where the load cells are placed on the unsprung end of thetie rod 33. If the load cell malfunctions or is not calibrated properly the hydraulic jack can be utilized to determine the load within the system. - If it is determined that the system load is outside of the predefined limits, the
cylinder 1 will be activated to unload thegear nut 3. Ahub 2 transmits the force from thehydraulic cylinder 1 to the binding plate 11 while allowing thegear nut 3 to rotate. Once thegear nut 3 is unloaded themotor 7 will be engaged in order to rotate thepinion 5 which is mounted directly on the shaft of themotor 7. The purpose of thepinion 5 is to transmit the rotational power of themotor 7 to thegear nut 3. Due to space requirements, in some instances anidle gear 4 will be installed between thepinion 5 and thegear nut 3. Its purpose is only to transmit the motion between the two. A gear setcover 6 protects the gear train against dirt and dust and also provides a reaction force acting opposite the rotational force of themotor 7. Themotor 7 is engaged such that thegear nut 3 will be rotated away from the binding plate 11 allowing room for the cylinder to adjust the binding load. The load in thehydraulic cylinder 1 will be set to match the design force thereby restoring the proper load to the system. At this point themotor 7 rotates thegear nut 3 back until it makes contact with the binding plate 11. After thegear nut 3 stops rotating, the remaining pressure is released from the hydraulic circuit and the system comes to rest. The frequency of these actions will depend on the furnace operation and the frequency of adjustment can be reduced by installing compressions springs 9 within the system. - The
hydraulic cylinder 1 is installed close to its fully extended position during the initial installation. Over time this extension will compensate for the expansion of the furnace 10. As the furnace grows thecylinder 1 will get shorter. It is worth noting that the estimated expansion of the furnace should correspond to the length of the stroke of thehydraulic cylinder 1 to prevent having to reset the hydraulic system prior to the furnace end of life. - The
gear nut 3 serves a dual purpose; during normal operation thegear nut 3 transfers the binding load between thetie rod 33 and the binding plate 11. During the self-adjusting period thegear nut 3 is disengaged and the gear is used to move thegear nut 3 back and forth in order to keep the load on thetie rod 33 constant. - A
hydraulic cylinder saddle 8 can be utilized to support the weight of thecylinder 1 while thecylinder 1 is unloaded. - An alternative arrangement of a similar embodiment utilizes a sprocket and chain in place of the gear train to transfer the motor rotation to the nut.
- For rectangular furnaces, in addition to maintaining the proper design loads the verticality, or plumbness, of the buckstays will be monitored to ensure that the buckstays remain plumb within a certain predefined distance. If the buckstays exceed the allowable out-of-plumbness the hydraulic motors and jacks will be utilized as described above to re-plumb the buckstays.
- This method eliminates the need for a manual check and adjustment of the binding loads.
- Turning to
Figures 7 and8 , a second embodiment of an auto-tensioning device is shown. It can be described as made of two hollow jacks in series coupled with accumulators and an associated gas (nitrogen, air, or other) supply system. Based on the pressure applied by the furnace on the jacks a PLC controls the pressure on the accumulator increasing or decreasing it based on the design load. - The basic principle of operation is the two
hydraulic cylinders 21 are installed in series close to their fully extended position. Over time this extension will compensate for the expansion of the furnace 10. As the furnace 10 grows, the cylinder will get shorter. The back-to-back cylinders 21 provide two important functions: 1) allowing the cylinders to cycle through their stroke while maintaining a constant load on the furnace and 2) redundancy, in the event that one hydraulic cylinder fails, the second will maintain the design load. Thehydraulic cylinders 21 apply the design load to the furnace through atie rod accumulator 29 and determines if the pressure varies from the design pressure by more than the predefined limit which would indicate that the system requires adjustment. Theaccumulator 29 acts as a spring, as the furnace expands and contracts, the gas within the accumulator is compressed and expands. A valve adds additional gas to the system through thegas supply line 25 to increase the load and a relief valve releases gas to decrease the load within the system. A non-flammable hydraulic fluid is supplied to thehydraulic cylinders 21 through the hydraulic supply line attached to theaccumulator 29. Rubber bellows 26 are positioned at either end of the hydraulic cylinder to seal and protect the internal components from heat and dust contamination. Anisolation nut 23 is included and serves two purposes: 1) it can be tightened thereby removing load from the hydraulic system while maintaining load on the buckstay allowing the system to be serviced or replaced with the load removed; or 2) it acts as a mechanical failsafe in the event that there is a failure of the hydraulic system. Astandoff 28 offsets the hydraulic binding system away from the furnace to allow space for theisolation nut 23. - The gas pressure within each
accumulator 29 is monitored through pressure gauges and the data fed back to the PLC which equates the pressure to an applied load. The load will be monitored to determine if it deviates from the prescribed load range. The hydraulic system has three modes of adjustment; decreasing binding load, increasing binding load, and cycling the jacks to ensure all seals are properly lubricated and to prevent seizure. The three modes of adjustment are described below. - As the furnace expands the binding forces increase as the non-flammable hydraulic fluid is pushed out of the hydraulic cylinders into the
accumulator 29 thus increasing the gas pressure within theaccumulator 29. - The gas pressure within the
accumulator 29 is allowed to increase up to a set maximum pressure. As the pressure increases within theaccumulator 29 it acts as a spring buffering the load applied to the furnace. - If the maximum pressure is reached some gas is released from the system through a relief valve thereby decreasing the pressure within the
accumulator 29 and in turn decreasing the binding load back to the design load. - As the furnace contracts the binding load decrease as the non-flammable hydraulic fluid is pushed into the hydraulic cylinders from the accumulator thus decreasing the gas pressure within the accumulator.
- The gas pressure within the accumulator is allowed to decrease down to a set minimum pressure. As the pressure is decreases within the accumulator it is acting as a spring maintaining load onto the furnace.
- If the minimum pressure is reached some gas is inserted into the system from the gas supply line through a valve thereby increasing the pressure within the accumulator and in turn increasing the binding load back to the design load.
- Periodically the cylinders are cycled in order to ensure the seals are properly lubricated and the cylinders do not seize. The binding load is to be maintained within the defined load range throughout the cycling operation.
- One of the two accumulators decreases the pressure by releasing gas through the relief valve. Gas is added to the second accumulator to accommodate the decreased pressure from the first. This method, while decreasing the stroke of one cylinder, increases the stroke of the second cylinder to match through a series of small steps to ensure proper binding loads are maintained throughout the process.
- Once one cylinder has reached its maximum stroke, and the other its minimum stroke the process reverses until the two cylinders reach the opposite range of their stroke.
- The two cylinders then return to their starting position such that the two cylinders each have the same stroke.
- The third embodiment of an auto-adjusting device is shown in
Figure 9 . It can be likened to a screw jack powered by a hydraulic or electric motor. - The basic principle of operation is the binding load on each tie rod will be monitored through
load cells 121 and the data fed back to the PCP. The load is monitored to determine if it deviates from the prescribed load range. When the binding load is determined to be outside of the prescribed range, themotor 7 turns theworm 113 which in turn rotates theworm gear 112. The binding load can be increased or decreased dependent upon the direction of rotation of themotor 7. A load bearing 111 is included to take both the vertical and horizontal loads. Ahousing 114 and a housing cap 110 protect the worm drive and associated hardware from dirt and dust. Aspring 9 can be utilized to reduce the frequency of adjustment. - The worm drive can be custom designed or utilize an existing screw jack design depending on the load and space requirements.
- For rectangular furnaces, in addition to maintaining the proper design loads, the verticality, or plumbness, of the buckstays will be monitored to ensure that the buckstays remain plumb within a certain predefined distance. If the buckstays exceed the allowable out-of-plumbness, the hydraulic motors and jacks will be utilized as described above will be utilized to re-plumb the buckstays.
- The present subject matter can thus automate the binding adjustment procedure for all forms of furnace bindings; primary and secondary hearth bindings, horizontal wall bindings, vertical wall hold down binding, and circular shell bindings. Specifically, the apparatus is intended to apply the specified design binding loads to the furnace refractory through all phases of the furnace operation without requiring regular manual adjustment. The hydraulic systems can be used with or without binding springs.
- The proposed apparatus can be applied to new smelting furnaces being built or retrofitted to improve existing smelting furnaces. The proposed apparatus can be applied to furnaces with a large number of binding load points or furnaces with as little as one binding system.
Claims (11)
- An auto-adjusting device for a binding system for a metallurgical furnace, comprising:a gauge or sensor that measures one of either the furnace binding forces, or the pressure of a hydraulic system that applies load to the furnace; anda load adjustment mechanism responsive to a measurement by the gauge or sensor that exceeds a predetermined amount, either above or below the desired load, and then automatically adjusts the load of the binding system,wherein the load adjustment mechanism comprises a hydraulic motor (7) and a gear train (3, 4, 5), said gear train (3, 4, 5) comprising a gear nut (3),
the auto-adjusting device for a binding system for a metallurgical furnace further comprising:a load cell (121) that measures the furnace binding forces and determines when the load varies by more than a pre-defined limit from a set point; anda hub (2) and a hydraulic cylinder (1) in series with the hydraulic motor (7) and gear train (3, 4, 5). - The auto-adjusting device of claim 1, wherein the hydraulic motor (7) is designed as a power screw to turn the gear nut (3) while the nut (3) is under load.
- The auto-adjusting device of any one of claims 1 to 2, wherein the load cell (121) is connected to a tie member (33) of the furnace binding in an adjustment system.
- The auto-adjusting device of claim 1, comprising two hollow jacks (21) in series coupled with accumulators (29) and an associated gas supply system.
- The auto-adjusting device of claim 4, further comprising a pressure gauge that measures the pressure within the accumulator and determines of the pressure varies from the design pressure by more than a predefined limit.
- The auto-adjusting device of claim 5, further comprising a valve to add additional gas from the gas supply system.
- The auto-adjusting device of claim 1, wherein the load adjustment mechanism comprises a motor (7) and a worm gear (112, 113) that acts upon the tie member of the binding system.
- The auto-adjusting device of claim 7, further comprising a load cell (121) on the tie member (33) of the binding system to monitor if the binding load deviates from a prescribed load range.
- The auto-adjusting device of claim 8, further comprising at least one spring (9).
- The auto-adjusting device of any one of the preceding claims, further comprising means to monitor the verticality of the furnace buckstays.
- Method of operation of an auto-adjusting device of claim 1, comprising the following steps:- the load cell (121) measures the furnace binding forces and determines when the load varies by more than a pre-defined limit from the set point indicating that the system requires adjustment,- when it has been determined that the binding load requires adjustment, the hydraulic cylinder (1) is engaged and set to exceed the load being applied in order to off-load the gear nut (3),- the hydraulic motor (7) is engaged to set the gear nut (3) back with a preset number of revolutions,- the hydraulic cylinder (1) sets the binding load to the design load,- the hydraulic motor (7) is engaged to set the gear nut (3) back into contact with a bearing plate,- the hydraulic cylinder (1) is unloaded and the load cell or cells (121) check to ensure the proper load is being applied to the system.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201161540961P | 2011-09-29 | 2011-09-29 | |
PCT/CA2012/000914 WO2013044372A1 (en) | 2011-09-29 | 2012-10-01 | Auto-adjusting binding system for metallurgical furnace |
Publications (3)
Publication Number | Publication Date |
---|---|
EP2761242A1 EP2761242A1 (en) | 2014-08-06 |
EP2761242A4 EP2761242A4 (en) | 2015-05-20 |
EP2761242B1 true EP2761242B1 (en) | 2016-09-21 |
Family
ID=47994070
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP12835429.7A Active EP2761242B1 (en) | 2011-09-29 | 2012-10-01 | Auto-adjusting binding system for metallurgical furnace |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP2761242B1 (en) |
ES (1) | ES2603978T3 (en) |
PL (1) | PL2761242T3 (en) |
WO (1) | WO2013044372A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2022070122A1 (en) * | 2020-10-02 | 2022-04-07 | Metix (Pty) Limited | Binding system for a furnace |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108826959B (en) | 2013-12-20 | 2020-04-14 | 魁北克9282-3087公司(加钛顾问公司) | Metallurgical furnace and method for retrofitting a metallurgical furnace |
CN114046665A (en) * | 2021-11-26 | 2022-02-15 | 佛山市凌赫热能科技有限公司 | Self-detection kiln pressure compensation device |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE618216C (en) * | 1932-09-06 | 1935-09-04 | Eduard Wecke | Method and device for preventing the destruction of vaulted and suspended ceilings |
US2994288A (en) * | 1959-05-06 | 1961-08-01 | Harbison Walker Refractories | Expansion and contraction control of refractory furnace roofs |
US3197385A (en) | 1961-12-06 | 1965-07-27 | Allied Chem | Process of cooling down a regenerative coke oven battery |
US3379177A (en) * | 1966-12-29 | 1968-04-23 | Combustion Eng | Buckstay connection for furnace walls |
US3869996A (en) | 1972-09-02 | 1975-03-11 | Viktor Mikhailovich Panferov | Method and apparatus for extending life period of furnace roofs |
DE3044897A1 (en) * | 1980-11-28 | 1982-07-08 | Krupp-Koppers Gmbh, 4300 Essen | CLAMPING SYSTEM TO AVOID HARMFUL TENSION AND SHEARING TENSIONS IN ANY MULTI-LAYER WALLWORK DISKS |
-
2012
- 2012-10-01 WO PCT/CA2012/000914 patent/WO2013044372A1/en active Application Filing
- 2012-10-01 EP EP12835429.7A patent/EP2761242B1/en active Active
- 2012-10-01 PL PL12835429T patent/PL2761242T3/en unknown
- 2012-10-01 ES ES12835429.7T patent/ES2603978T3/en active Active
Non-Patent Citations (1)
Title |
---|
None * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2022070122A1 (en) * | 2020-10-02 | 2022-04-07 | Metix (Pty) Limited | Binding system for a furnace |
Also Published As
Publication number | Publication date |
---|---|
EP2761242A4 (en) | 2015-05-20 |
PL2761242T3 (en) | 2017-01-31 |
ES2603978T3 (en) | 2017-03-02 |
WO2013044372A1 (en) | 2013-04-04 |
EP2761242A1 (en) | 2014-08-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2761242B1 (en) | Auto-adjusting binding system for metallurgical furnace | |
RU2647044C2 (en) | Metallurgical furnace | |
ZA200503735B (en) | Furnace binding and adjustment systems. | |
US8245653B2 (en) | Split shell circular furnace and binding systems for circular furnaces | |
EP1756503B1 (en) | System for applying vertical compressive force to furnace walls | |
TWI390126B (en) | Torque support for a converter tilting drive | |
MXPA03001700A (en) | Thermal contraction control apparatus for hydraulic cylinders. | |
JP2010216534A (en) | Piston inclination suppressing device and method for gas holder | |
KR101235259B1 (en) | Device for adjusting tension of tie rod in coke oven and method for thereof | |
RU2746165C1 (en) | Method for frictional compensation of movements of continous welded rail track and device for its implementation | |
KR100979036B1 (en) | An apparatus for supporting coke oven structure | |
FI130412B (en) | Lifting system | |
CN217131808U (en) | Support structure of stand and roller kiln | |
JPH077303Y2 (en) | End face pressing device for coke oven direction | |
SU872566A1 (en) | Convertor | |
RU72246U1 (en) | GAS-FILLED ROOF (OPTIONS) | |
SU1609816A1 (en) | Transverse anchor of coke oven battery | |
KR19990006999U (en) | Expansion pressure compensator with coke oven refractory smoke |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20140428 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
DAX | Request for extension of the european patent (deleted) | ||
RA4 | Supplementary search report drawn up and despatched (corrected) |
Effective date: 20150417 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: F27B 3/10 20060101ALI20150413BHEP Ipc: F27D 1/14 20060101AFI20150413BHEP Ipc: F27B 3/08 20060101ALI20150413BHEP Ipc: C21B 11/08 20060101ALI20150413BHEP Ipc: F27B 3/28 20060101ALI20150413BHEP Ipc: F27D 19/00 20060101ALI20150413BHEP Ipc: C22B 9/02 20060101ALI20150413BHEP |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
INTG | Intention to grant announced |
Effective date: 20160316 |
|
GRAJ | Information related to disapproval of communication of intention to grant by the applicant or resumption of examination proceedings by the epo deleted |
Free format text: ORIGINAL CODE: EPIDOSDIGR1 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
INTC | Intention to grant announced (deleted) | ||
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
INTG | Intention to grant announced |
Effective date: 20160726 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 831390 Country of ref document: AT Kind code of ref document: T Effective date: 20161015 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602012023378 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D Ref country code: NL Ref legal event code: MP Effective date: 20160921 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20161221 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 831390 Country of ref document: AT Kind code of ref document: T Effective date: 20160921 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20161222 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161031 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: BE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170123 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20170121 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20161221 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602012023378 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20170630 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161031 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161031 Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161121 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20161221 |
|
26N | No opposition filed |
Effective date: 20170622 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161001 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161001 Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161221 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20121001 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161031 Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20160921 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230526 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: PL Payment date: 20230922 Year of fee payment: 12 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20231108 Year of fee payment: 12 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FI Payment date: 20231005 Year of fee payment: 12 Ref country code: DE Payment date: 20231006 Year of fee payment: 12 |