The disclosure relates to furnaces, and more particularly to a cooling element of a furnace. The present disclosure further concerns a method in connection with such a cooling element.
In connection with furnaces used for industrial purposes, particularly in the manufacturing of metals, such as flash smelting furnaces, blast furnaces and electric furnaces or other metallurgic reactors, there are used cooling elements. Cooling elements are typically made of mainly copper due to its good thermal conductivity. Typically, these cooling elements are cooled by water and thus provided with a cooling water channel system, in which case the heat is transferred from the fire-resistant bricks in the furnace space, via the housing of the cooling element, to the cooling water. The working conditions are extreme, and the cooling elements are subjected, among other things, to strong corrosion and erosion strains caused by the furnace atmosphere or molten contacts. Over time, wear and damages may occur in the cooling element. If the damages reach the cooling water channel system, the cooling water may leak out to the inside of the furnace, which may lead to process failures, unplanned service breaks and remarkable economic losses.
An object of the present disclosure is to provide a new cooling element and a new method in connection with a cooling element. The object is achieved by a method and a cooling element, which are characterized by what is stated in the independent claims. Some preferred embodiments of the disclosure are disclosed in the dependent claims.
The disclosure is based on the idea of providing a monitoring channel system inside the cooling element. More particularly, a monitoring channel system is provided inside the cooling element between cooling fluid channel system and the surface facing towards the inside of the furnace, when the cooling element is mounted to the furnace for use.
An advantage of the method and arrangement of the disclosure is that wear in the cooling element can be detected before the possible damages reach the cooling fluid channel system. This way needs for repairing or replacing the cooling elements can be predicted and process downtime can be planned and optimized with other maintenance needs. Furthermore, the disclosure provides an effective monitoring arrangement with a simple structure and less components and wiring than in known solutions.
In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which
The drawings are provided for illustrative purposes only, whereby they are not shown to scale and not all the corresponding features are provided with
A furnace 1 typically comprises a furnace housing 2 and inside the furnace housing a furnace space, in other words an inside 3 of the furnace, within which the material to be processed can be provided. According to an embodiment, the furnace 1 is used for industrial purposes. According to an embodiment, the furnace is more particularly used in manufacturing of metals. Such a furnace 1 may comprise a flash smelting furnace, a blast furnace, an electric furnace or another type of a metallurgic reactor.
Typically, furnaces of the above-mentioned types, such as the furnace of
According to an embodiment, a cooling element 4 may comprise copper. According to an embodiment, at least 50 percent of the volume of a cooling element 4 may consist of copper. More preferably at least 60 percent and most preferably at least 70 percent of the volume of a cooling element 4 may consist of copper. According to an embodiment, a cooling element 4 may comprise other material(s) in addition to or instead of copper.
Cooling elements 4 may be cooled by a cooling fluid, such as a cooling liquid, circulated inside the cooling element. For this purpose, a cooling fluid channel system 6 may be provided inside the cooling element 4. Thus, the heat may be transferred from the fire-proof lining 5, via a housing of the cooling element 4, to the cooling liquid.
An advantage of embodiments, wherein the cooling element 4 comprises a high percentage of copper, such as 50, 60 or 70 percent of the volume, is that copper has particularly good thermal conductivity and, thus, the cooling element 4 can effectively transfer heat from the surface directed towards the inside 3 of the furnace, for instance from a fireproof lining 5, to the cooling fluid in the cooling fluid channel system 6. The cooling element 4 may be provided with grooves or ridges, and the fireproof lining 5 may comprise for instance ceramic members, such as fireproof bricks made of ceramic or other type of material.
The cooling element 4 also comprises a cooling fluid channel system 6 for cooling fluid circulation. The cooling fluid channel system 6 comprises at least one cooling fluid channel 9 provided inside the cooling element 4. According to an embodiment, the cooling element 4 comprises two or more cooling fluid channels 9. Each cooling fluid channel 9 is configured to receive cooling fluid. Thus, cooling fluid circulation can be configured to take place in the cooling fluid channel system 6. Cooling fluid circulation and cooling fluid channels are known in the art and are thus not discussed here in detail.
The cooling element 4 further comprises a monitoring channel system 10. The monitoring channel system 10 comprises at least one monitoring channel 11 for pressure medium. In other words, the monitoring channel 11 is configured to receive pressure medium. Pressure and/or flow in the monitoring channel 11 can be monitored and the data can be used for monitoring a condition, such as wear, of the cooling element 4. More particularly, the data can be used to detect wear of the cooling element 4 on the first side 7 directed towards the inside 3 of the furnace 1 and is, thus, exposed to high temperatures. Monitoring the condition of the cooling element 4 is described in more detail later in connection with other embodiments. Such monitoring channel(s) 11 enable detecting wear before it reaches the cooling fluid channel(s) 9. The cooling element 4 can thereby be for instance replaced or repaired before there is a risk of the cooling fluid coming into contact with the inside 3 of the furnace 1. According to an embodiment, the monitoring channel system 10 comprises exactly one monitoring channel 11 for pressure medium.
Depending on the embodiment, cooling element 4 may be manufactured for instance by casting, such as continuous casting, mould casting or sand casting. Depending on the embodiment, the monitoring channel 11 and the monitoring channel system 10 may be formed in the cooling element 4 by machining, such as by drilling, or in connection with casting and/or moulding.
At least a portion 12 of the monitoring channel 11 extends in a portion 13 of the cooling element provided between the first side 7 and a plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7. This is shown for instance in
A monitoring channel 11 or some other structural feature extending in a direction or plane or within a portion refers to the structural feature having a substantial dimension in that direction or plane or within that portion. In the context of this description, for instance a straight borehole is understood to extend in the longitudinal direction of the borehole, in other words in the direction of the forward motion of the drill, but not in a direction perpendicular to the longitudinal direction, although a borehole naturally has a diameter as well. A curved monitoring channel 11, such as a monitoring channel of
According to an embodiment, the dimension of the monitoring channel 11 extending in the portion 13 of the cooling element between the first side 7 and a plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7 may be at least 10 times the diameter 20 of the monitoring channel 11, and preferably at least 50 times the diameter 20 of the monitoring channel 11. According to an embodiment, the dimension of the monitoring channel 11 extending in the portion 13 of the cooling element between the first side 7 and a plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7 may be at least 70 percent of the length of a cooling fluid channel 9. According to an embodiment, the dimension of the monitoring channel 11 extending in the portion 13 of the cooling element between the first side 7 and a plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7 may be at least 1 meter long, preferably at least 4 meters long. According to an embodiment, the sum of the dimensions of the monitoring channels 11 extending in the portion 13 of the cooling element 4 between the first side 7 and a plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7 may be at least 1 meter long, preferably at least 4 meters long.
The points 15 of the cooling fluid channel system 6 closest to the first side 7 refer to three or more points of the interface between the cooling fluid channel(s) 9 of the cooling fluid channel system 6 with the shortest distance 16 from the first side 7 measured in a direction transverse to the first side 7. In other words, the shortest distance 16 is measured from the surface of the first side 7 configured to be directed towards the inside 3 of the furnace. The plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7 refers to a plane extending through all the points 15, such as illustrated in
The portion 12 of the monitoring channel 11 may also be called a monitoring channel portion 12 and, similarly, the portion 13 of the cooling element may also be called a cooling element portion 13 in this description. Depending on the embodiment, the monitoring channel 11 may also comprise other portions in addition to portion 12, such as a portion extending outside the cooling element 4 and/or a portion extending a direction perpendicular to the plane 14 and/or the first side 7.
According to an embodiment, the portion 12 of the monitoring channel extends in at least one of the following directions: in a direction parallel to the plane 14, in a direction parallel to at least a part of a surface of the first side 7, or in a direction provided at an angle X of 30 degrees or less, preferably 10 degrees or less, with respect to the plane 14. In other words, the monitoring channel portion 12 extends between the plane 14 and the first side 7, more particularly the surface of the first side 7 directed towards the inside 3 of the furnace, when the cooling element 4 is mounted to the furnace. More particularly, the mounting channel portion 12 in a direction angled 30 degrees or less, preferably 10 degrees or less, with respect to the plane 14 and/or in a direction parallel to at least a part of the surface of the first side 7. In practice this means that the mounting channel portion 12 extends within the cooling element 4 between the plane 14 and the first side 7 in a direction substantially parallel or slightly angled with respect to at least a part of the surface of the first side 7. An angle X between the plane 14 and the monitoring channel 11 according to an embodiment is shown in
In some embodiments, such as in the embodiment of
According to an embodiment, such as the embodiment of
According to an embodiment, such as the embodiments of
According to an embodiment, at least some of the monitoring channels 11 are connected to one another by at least one connecting channel 17 provided outside the cooling element 4 to form the monitoring channel system 10. According to an embodiment, at least two of the monitoring channels 11 are connected to one another by at least one connecting channel 17 provided outside the cooling element 4 to form the monitoring channel system 10.
According to an embodiment, in a cooling element, wherein the number of the monitoring channels 11 comprising at least a portion 12 of the monitoring channel extending in the portion 13 of the cooling element provided between the first side 7 and a plane 14 defined by the points 15 of the cooling fluid channel system 6 closest to the first side 7, is in the range of 0.2 to 2.0 times the number of the cooling fluid channels 9, preferably 0.8 to 1.5 times and most preferably one monitoring channel per a cooling fluid channel 9, when the cooling element 4 is seen is cross section as in
According to an embodiment, such as according to the embodiments of
According to an embodiment, such as the embodiment of
According to an embodiment, such as the embodiment of
It should be understood that two or more monitoring channels 11 shown in the figures may in each case be either connected, even if this was not shown in the figure, and thus form one single monitoring channel 11, or they may be separate monitoring channels 11.
According to an embodiment, the diameter 20 of the monitoring channel 11 is in the range of 6-20 mm, and more preferably in the range of 8-13 mm.
According to an embodiment, each of the monitoring channels 11 is closed at one end and configured to be connected to a pressure medium supply system (not shown) directly or via a connecting channel at a second end.
According to an embodiment, the cooling element 4 further comprises at least one detector 21 connected to the at least one monitoring channel 11 of the monitoring channel system 10 and arranged to detect at least one of the following quantities: pressure in the monitoring channel system, a change in the pressure in the monitoring channel system, flow in the monitoring channel system, or a change in the flow in the monitoring channel system. According to an embodiment, the cooling element 4 comprises exactly one detector 21 connected to the monitoring channel system 10. According to an embodiment, the cooling element 4 comprises exactly one monitoring channel system 10 and exactly one detector 21 connected to the monitoring channel system. According to an embodiment, the detector 21 comprises at least a pressure sensor or a flow meter.
According to an embodiment, in the cooling element 4, each monitoring channel 11 of the monitoring channel system 10 is suitable for the pressure medium having a supply pressure in the range of 0.2 to 10 bar, preferably in the range of 0.4 to 4 bar, and the pressure medium comprising pressurized air, nitrogen or other pressurized gas. In embodiments, where regulation, such as a pressure equipment directive or similar, applies, the supply pressure may be in the range of 0.2 to 0.5 bar.
According to an embodiment, the cooling element 4 is a cooling element suitable for use in a furnace 1 related to a metal production process.
The cooling arrangement 22 according to
According to an embodiment, the pressure medium supply system 24 comprises a supply line 30 for the pressure medium, and the supply line 24 for pressure medium is provided with pressure regulating means 25 arranged to reduce the pressure of the supply line 30 to a predetermined value. According to an embodiment, the predetermined value is in the range of 0.2 to 10 bar, preferably in the range of 0.4 to 4 bar. In embodiments, where regulation, such as a pressure equipment directive or similar, applies, the predetermined value may be in the range of 0.2 to 0.5 bar.
According to an embodiment, the cooling arrangement 22 comprises at least one detector 21 according to an embodiment or a combination of embodiments disclosed in connection with the cooling element 4 embodiments. The detector 21 may then be configured to detect the pressure and/or the flow in the monitoring channel system 10. The cooling arrangement may further comprise a monitoring unit 26 for determining whether a predefined condition related to the quantity detected by the detector is met. According to an embodiment, the measured quantity may comprise at least one of the following: pressure in the monitoring channel system and flow in the monitoring channel system. According to an embodiment, the predefined condition comprises at least one of the following: the detected pressure decreasing to a predetermined value or below it, the detected flow increasing to a predetermined value or below it, the detected pressure decreasing by a predefined threshold, or the detected flow increasing by a predefined threshold.
According to an embodiment, the detector 21 is configured to monitor the pressure and/or flow in the monitoring channel system 10 continuously or at predetermined time intervals.
According to an embodiment, the cooling arrangement 22 further comprises flow limiting means 27 provided in the supply line 24 for the pressure medium, and wherein the detector 21 is provided downstream from the flow limiting means 27.
According to an embodiment, at least one of the monitoring channels 11 of the monitoring channel system 10 is provided with a valve 28 capable of opening and closing pressure medium flow in the monitoring channel(s) 11. According to a further embodiment, each monitoring channel 11 of the monitoring channel system 10 is provided with a valve 28 capable of opening and closing pressure medium flow in the monitoring channel. In such embodiments, when an incident is identified in the monitoring channel system 10, its source can be located more precisely. For instance, when a condition related to the quantity detected by the detector is met, the valve(s) may be closed one at a time, and the monitoring channel 11 or a part thereof causing the condition can be located by monitoring measured quantity. More particularly, when the pressure medium flow to the monitoring channel 11 or a part thereof causing the condition is closed by closing the corresponding valve 28, the pressure detected by the detector 21 starts to increase.
According to an embodiment, a cooling arrangement 22 comprises two or more cooling elements 4 and exactly one detector 21. According to an embodiment, one cooling arrangement 22 with one monitoring unit 26 and one detector 21 may be used to monitor two or more cooling elements 4. In such embodiments, the monitoring channels 11 of the cooling elements 4 are connected to each other by a fluid connection.
According to an embodiment, a furnace 1 may comprise at least one cooling element 4 and/or a cooling arrangement 22 according to an embodiment or a combination of embodiments disclosed in this description and/or accompanying drawings. According to an embodiment, the furnace 1 is a furnace related to a metal production process.
The method according to
According to an embodiment, the cooling element 4 further comprises one or more valves 28 capable of opening and closing pressure medium flow in the monitoring channel(s) 11. According to an embodiment, the valve(s) 28 may be provided in at least one of the monitoring channels 11 of the monitoring channel system 10. The method may, then, further comprise opening and closing the valve(s) 28 one or several at a time to locate the wear causing a drop in the pressure and/or flow in the control system channel.
According to an embodiment, wherein the monitoring unit 26 may be configured to generate a signal causing indication of the wear to an operator.
The method of
Filing Document | Filing Date | Country | Kind |
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PCT/FI2021/050603 | 9/10/2021 | WO |