The invention relates to a method for monitoring the condition of a wearing component as defined in the preamble of independent claim 1.

The invention also relates to an arrangement for monitoring the condition of a wearing component as defined in the preamble of independent claim 6.

In strand sintering furnaces cast iron blocks are used to protect the underlining sliding table against wear. These blocks are wearable parts and they need to be changed periodically. Due to the nature of strand sintering furnaces, these parts are difficult to inspect. It can only be made during steel belt change which is done for example annually. Cast iron blocks have a long lead time so it is important that parts are ordered well in advance of the planned change. Lead time combined with demanding inspection causes a problematic situation.

Objective of the invention

The object of the invention is to provide a method and an arrangement for monitoring the condition of a wearing component, which can for example be used for monitoring of the condition of cast iron blocks of strand sintering furnaces or for monitoring of the condition of other wearing components.

Short description of the invention

The method for monitoring the condition of a wearing component is characterized by the definitions of independent claim 1.

Preferred embodiments of the method are defined in the dependent claims 2 to 5.

The arrangement for monitoring the condition of a wearing component is correspondingly characterized by the definitions of independent claim 6.

Preferred embodiments of the arrangement are defined in the dependent claims 7 to 10. The invention relates also to the of the method according to any of the claims 1 to 5 to monitor the condition of a wearing component in the form of a cast iron block in contact of which an endless conveyor belt of a strand sintering furnace is configured to run, as defined in claim 11.

The invention relates also to the use of the arrangement according to any of the claims 6 to 10 to monitor the condition of a wearing component in the form of a cast iron block in contact of which an endless conveyor belt of a strand sintering furnace is configured to run, as defined in claim 12.

The invention relates also to a strand sintering furnace as defined in claim 13.

With the method and the arrangement is possible to monitor the condition of a wearing component such as the condition of a cast iron block of a strand sintering furnace continuously or on-line.

The sensors can be either of on/off-type or be of more advanced type configured for example to measure material thickness of the wearing component.

Several sensors can be connected to a Process Control System (PCS) or other monitoring system.

List of figures

In the following the invention will described in more detail by referring to the figures of which

Figure 1 shows a strand sintering furnace in longitudinal cross section,

Figure 2 shows cast iron blocks in contact of which an endless conveyor belt of a strand sintering furnace is configured to run,

Figure 3 shows a strand sintering furnace in transversal cross section,

Figure 4 shows a first embodiment of a cast iron block of a strand sintering furnace, Figure 5 shows a second embodiment of a cast iron block of a strand sintering furnace, Figure 6 shows a third embodiment of a cast iron block of a strand sintering furnace, Figure 7 shows a curved tube section, and

Figure 8 shows a curved tube section that is provided with a lining.

Detailed description of the invention

First the method for monitoring the condition of a wearing component 1 and some embodiments and variants of the method will be described in greater detail.

The method comprises providing the wearing component 1 with a first hole 2 that can have a first bottom 3 at a first distance A as measured from a surface 4 of the wearing component 1.

The method comprises providing a first electrical sensor 5 in the first hole 2 at a second distance B from the surface 4 of the wearing component 1.

The method comprises supplying electrical energy to the first electrical sensor 5 to produce first signals with the first electrical sensor 5.

The method comprises receiving first signals produced by the first electrical sensor 5 until the wearing component 1 at said surface 4 has worn to a first threshold thickness.

The method may comprise short-circuiting the first electrical sensor 5 or cutting an electrical energy supply to the first electrical sensor 5 when said first threshold thickness of the wearing component 1 is reached, with the result that the first electrical sensor 5 is unable to produce first signals to be received by the receiving means.

The first electrical sensor 5 that is provided can be an inductive, capacitive, magnetic, laser or fiber optic sensor.

An embodiment of the method comprises providing the wearing component 1 with a second hole 6 that can have a second bottom 7 at a third distance C as measured from a surface 4 of the wearing component 1. The third distance C can be different than the first distance A. This embodiment of the method comprises providing a second electrical sensor 8 in the second hole 6 at a fourth distance D from the surface 4 of the wearing component, wherein the fourth distance D is different from the second distance B. This embodiment of the method comprises supplying electrical energy to the second electrical sensor 8 to produce second signals with the second electrical sensor 8, and receiving second signals produced by the second electrical sensor 8 until the wearing component 1 at said surface 4 has worn to a second threshold thickness. Figure 5 shows an embodiment with a first electrical sensor 5 and a second electrical sensor 8.

The method may comprise short-circuiting the second electrical sensor 8 or cutting an electrical energy supply to the second electrical sensor 8 when said first threshold thickness of the wearing component 1 is reached, with the result that the second electrical sensor 8 is unable to produce second signals to be received by the receiving means.

The second electrical sensor 8 that is provided can be an inductive, capacitive, magnetic, laser or fiber optic sensor.

An embodiment of the method, as shown in figure 6, comprises providing both a first electrical sensor 5 and a second electrical sensor 8 in the first hole 2 in the wearing component 1. The first electrical sensor 5 is provided at a second distance B from the surface 4 of the wearing component 1 and the second electrical sensor 8 is provided at a fourth distance D from the surface 4 of the wearing component 1. This embodiment of the method comprises supplying electrical energy to the first electrical component 5 to produce first signals with the first electrical sensor 5 and supplying electrical energy to the second electrical sensor 8 to produce second signals with the second electrical sensor 8, and receiving first signals produced by the first electrical sensor 5 until the wearing component 1 at said surface 4 has worn to a first threshold thickness and receiving second signals produced by the second electrical sensor 8 until the wearing component 1 at said surface 4 has worn to a second threshold thickness.

In the method, the wearing component 1 can for example be any one of:

• A feeding pipe for feeding material into an electric arc furnace,

• A cast metal wear member on a sliding table,

• A hood of a strand sintering furnace,

• A launder of a distribution device of a Preheating Kiln,

• A lining of a combustion chamber of a burner,

• A curved tube section of a pneumatic conveyor, of a slurry duct, or of a dust duct, and

• A distribution cone of a dispersion apparatus of a concentrate of matte burner of a suspension smelting furnace.

Next the arrangement for monitoring the condition of a wearing component 1 and some embodiments and variants of the method will be described in greater detail.

The wearing component 1 is provided with a first hole 2 that may have a first bottom 3 at a first distance A as measured from a surface 4 of the wearing component 1.

A first electrical sensor 5 in the first hole 2 at a second distance B from the surface 4 of the wearing component 1.

The arrangement comprises electrical energy supplying means configured to supply electrical energy to the first electrical sensor 5 to produce first signals with the first electrical sensor 5, and receiving means configured to receive first signals produced by the first electrical sensor 5 until the wearing component 1 at said surface 4 has worn to a first threshold thickness.

The first electrical sensor 5 can be an inductive, capacitive, magnetic, laser or fiber optic sensor.

The first electrical sensor 5 can for example be configured to be short-circuited or an electrical energy supply to the first electrical sensor 5 can be configured to be cut when said first threshold thickness of the wearing component 1 is reached, which is configured to result in that the first electrical sensor 5 is unable to produce first signals to be received by the receiving means.

In an embodiment of the arrangement, the wearing component 1 is additionally provided with a second hole 6 having a second bottom 7 at a third distance C as measured from a surface 4 of the wearing component 1. The third distance C can be different than the first distance A. This embodiment of the arrangement comprises a second electrical sensor 8 in the second hole 6 at a fourth distance D from the surface 4 of the waring component, wherein the fourth distance D is different from the second distance B. This embodiment of the arrangement comprises by electrical energy supplying means configured to supply electrical energy to the second electrical sensor 8 to produce second signals with the second electrical sensor 8, and receiving means configured to receive second signals produced by the second electrical sensor 8 until the wearing component 1 at said surface 4 has worn to a second threshold thickness. Figure 5 shows an embodiment with a first electrical sensor 5 and a second electrical sensor 8.

The second electrical sensor 8 can be an inductive, capacitive, magnetic, laser or fiber optic sensor.

The second electrical sensor 8 can for example be configured to be short-circuited or an electrical energy supply to the second electrical sensor 8 can be configured to be cut when said second threshold thickness of the wearing component 1 is reached, which is configured to result in that the second electrical sensor 8 is unable to produce second signals to be received by the receiving means.

In an embodiment of the arrangement, as shown in figure 6, both a first electrical sensor 5 and a second electrical sensor 8 is provided in the first hole 2 in the wearing component 1. The first electrical sensor 5 is provided at a second distance B from the surface 4 of the wearing component 1 and the second electrical sensor 8 is provided at a fourth distance D from the surface 4 of the wearing component 1. This embodiment of the arrangement comprises electrical energy supplying means configured to supply electrical energy to the first electrical component 5 to produce first signals with the first electrical sensor 5 and configured to supply electrical energy to the second electrical sensor 8 to produce second signals with the second electrical sensor 8, and receiving means configured to receive first signals produced by the first electrical sensor 5 until the wearing component 1 at said surface 4 has worn to a first threshold thickness and configured to receive second signals produced by the second electrical sensor 8 until the wearing component 1 at said surface 4 has worn to a second threshold thickness.

In the arrangement, the wearing component 1 can for example be any one of:

• A feeding pipe for feeding material into an electric arc furnace,

• A cast metal wear member on a sliding table ,

• A hood of a strand sintering furnace,

• A launder of a distribution device of a Preheating Kiln,

• A lining of a combustion chamber of a burner,

• A curved tube section of a pneumatic conveyor, of a slurry duct, or of a dust duct, and

• A distribution cone of a dispersion apparatus of a concentrate of matte burner of a suspension smelting furnace.

The invention relates also the use of the method or any embodiment of the method to monitor the condition of a wearing component 1 in the form of a cast iron block in contact of which an endless conveyor belt 9 of a strand sintering furnace is configured to run.

The invention relates also to the use of the arrangement or any embodiment of the arrangement to monitor the condition of a wearing component 1 in the form of a cast iron block in contact of which an endless conveyor belt 9 of a strand sintering furnace is configured to run.

The invention relates also to a strand sintering furnace comprising a number of sequential process zones 12a, 12b, 12c, 12d, 12e, 12f having different temperature conditions.

The strand sintering furnace comprising an endless conveyor belt 9, which is arranged around a deflector roll 10 and a driven roll 11 for conveying a pellet bed (not shown in the figures) through the process zones 12a, 12b, 12c, 12d, 12e and 12f of the strand sintering furnace in a direction of movement E, said endless conveyor belt 9 being gas permeable.

In the strand sintering furnace, the endless conveyor belt 9 running in contact with cast metal wear members arranged at a sliding table.

Each process zone 12a, 12b, 12c, 12d, 12e and 12f is provided with an upper gas feeding arrangement 13 configured to conduct gas to be sucked through the pellet bed and the conveyor belt 9 to the process zone 12a, 12b, 12c, 12d, 12e and 12f.

Each process zone 12a, 12b, 12c, 12d, 12e and 12f is provided with a lower exhaust gas arrangement 14 configured to conduct gas that was sucked through the pellet bed and the conveyor belt 9 away from the process zone 12a, 12b, 12c, 12d, 12e and 12f.

The strand sintering furnace comprises at least one arrangement according to any embodiment described, where the wearing component 1 is formed by a cast metal wear member of the strand sintering furnace, and where the endless conveyor belt 9 running in contact said surface 4 of the wearing component 1. An embodiment of the strand sintering furnace comprises six process zones 12a, 12b, 12c, 12d, 12e and 12f, wherein an arrangement for monitoring the condition of a wearing component is provided in at least the third process zone 12c and in the fifth process zone 12e as seen in the direction of movement E of said endless conveyor belt 9. An arrangement for monitoring the condition of a wearing component can also or alternatively be provided between the third process zone 12c and the fourth process zone 12d as seen in the direction of movement E of said endless conveyor belt 9.

It is apparent to a person skilled in the art that as technology advanced, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.