System and method for measuring cooling plate thickness in a blast furnace

Abstract

A system for measuring the thickness of a cooling plate, the system comprising: a probe holder unit (10) designed to fit inside a coolant passage (18) of a cooling plate (12), the probe holder unit (10) including a housing (30) extending along a length axis (L) and an ultrasonic probe (32) arranged in the housing so as to transmit and receive ultrasonic waves from a sensor side; a rear housing part (36) arranged movably at a rear side, elastically biased transversely to the length axis and away from the sensor side, thereby allowing the probe holder unit to adapt to the size of the cooling passage; a drive chain (14) for assisting the progression of the probe holder unit (10) over the length of the coolant passage, the drive chain being connected to a first connection means (48) at the first end of the housing. A cable assembly (60) including electrical wires connects the ultrasonic probe. The encoder structure (15) is configured to cooperate with the drive chain, such as to measure the length of the drive chain passing therealong, and includes a first gear (76) that meshes with the drive chain and is coupled to an encoder.

Description

[Technical field]

[0001] The present invention relates generally to cooling plates for metallurgical or blast furnaces, and more particularly to a system and method for measuring the remaining thickness of cooling plates. [Background technology]

[0002] Cooling plates for metallurgical furnaces, also called "staves", are well known in the art. They are used to line the inner walls of metallurgical furnace shells such as blast furnaces and electric arc furnaces: (1) a heat exhaust protection screen between the interior and exterior shell of the furnace; and (2) To provide anchoring means for the refractory brick lining, refractory gunite or process generated deposits in the furnace.

[0003] Cooling plates were originally cast iron plates with cooling tubes cast into them. As an alternative to cast iron staves, copper staves were developed. Today, most cooling plates in metallurgical furnaces are made of copper, copper alloys, or more recently steel.

[0004] A refractory brick lining, a refractory gunite material or a process-produced accretion layer forms a protective layer placed in front of the hot face of the panel-like body, which is useful for protecting the cooling plate from deterioration caused by the harsh environment prevailing in the furnace. However, in practice, furnaces are sometimes operated without this protective layer, which results in the erosion of the layered ribs of the hot face.

[0005] Although the blast furnace is initially provided with a refractory brick lining on the front side of the stave, this lining may wear out during the period depending on the operating conditions. It has been observed that the refractory lining may disappear relatively quickly, especially in the morning glory. A deposit of slag and burdening, which is usually formed on the hot side of the cooling plate, actually accumulates and wears out continuously, so that the cooling plate body is directly exposed to the harsh conditions in the blast furnace for a certain period of time, leading to wear.

[0006] The main cause of wear experienced by the deposits, and of course by the lining and cooling plates, is friction caused by the rising hot gas flow and the sinking heavy loads (coal, ores, etc.) For hot gas flow, wear is due not only to the thermal load but also to the abrasion caused by particles carried in the rising gas.

[0007] Thus, ultimately, the presence of a good adhesion layer is strictly linked to good conduction in the blast furnace and good condition of the stave ribs, with all the complexities that the process itself requires.

[0008] The wear state of the cooling plate ribs is particularly important; if they are not sufficiently "sharpened", sufficient adhesion of the adhesion layer itself is not possible, even if the conduction of the blast furnace is good.

[0009] For this reason, it is of utmost importance to regularly check the thickness of the cooling plates, especially the thickness of the ribs. Non-intrusive systems such as ultrasonic inspection techniques are preferred to minimize the impact on plant operations and avoid shutting down the plant and disrupting production.

[0010] The document JP 61-264110 A discloses a cooling stave that includes a wear detection system using an ultrasonic probe that contacts the rear face of the stave body to detect erosion thereon, allowing the measurement of the remaining body thickness between the front and rear faces.

[0011] Document KR20110076422 discloses a thickness measurement system, in which an ultrasonic probe is attached to the end of a flexible extension member, which allows the ultrasonic probe to be inserted in the inlet and outlet regions of the coolant channel. It is thus possible to actually measure the body thickness on the front side of the coolant plate and between the coolant channels. This information is useful, since it provides the remaining body thickness of the coolant channel, which is essential for the safe operation of the blast furnace, since water must be avoided from entering the furnace. However, this system only allows local measurements (at the beginning and / or end of the coolant channel), which is considered insufficient today to properly evaluate the condition of the coolant plate. In fact, experience has shown that in many cases the coolant plate wears more in the middle body part than at the ends. An evaluation based on this system therefore leads to an incorrect analysis of the actual general wear of the coolant plate and therefore to an incorrect prediction of its remaining life.

[0012] KR 101 594 719 B1 discloses a stave thickness measuring device in which an ultrasonic sensor unit is connected to a drive unit, which allows the ultrasonic sensor to be inserted into the stave and the sensor to be moved within the stave. It therefore makes it possible to perform thickness measurements along the entire length of the stave. However, the working principle requires the ultrasonic sensor unit to be installed at each measuring point, e.g. by deploying contact legs or inflating a balloon, to ensure close contact between the ultrasonic probe and the stave inner surface, which complicates the whole measuring process.

[0013] Other systems for measuring the thickness of staves are disclosed in JP 2010-271072 A and JP 2015-169548 A. WO 2020 / 161314 A discloses a thickness measuring device having an expandable structure including a pivotable lever. Summary of the Invention [Problem to be solved by the invention]

[0014] The object of the present invention is to provide an alternative and reliable method for monitoring the wear state of a cooling plate. This object is achieved by a system and a method for measuring the thickness of a cooling plate as set forth in claims 1 and 11. [Means for solving the problem]

[0015] The present invention relates to a system for measuring the thickness of a cooling plate, namely: a probe holder unit designed to fit within a coolant flow passage (also referred to as a cooling passage) of a cooling plate, the probe holder unit including a housing extending along a length axis from a first end to a second end on a side, a sensor side, and an opposite rear side, and an ultrasonic probe disposed within the housing so as to be capable of transmitting and receiving ultrasonic waves from the sensor side; a rear housing part movably arranged at the rear side, which is elastically biased transversely to the length axis and away from the sensor side, thereby allowing the probe holder unit to adapt to the size of the cooling channel; a drive chain for assisting in traveling the probe holder unit through the length of the coolant flow passage, the drive chain coupled to a first connection means at a first end of the housing; a cable assembly including wires connecting the ultrasound probe; an encoder structure configured to cooperate with the drive chain, such as to measure a length of the drive chain passing therealong, the encoder structure including a first gear meshing with the drive chain and coupled to the encoder; A system for measuring the thickness of a cooling plate is proposed, which includes:

[0016] The ultrasonic inspection system of the present invention has many advantages. The probe holder unit is self-adapting to the diameter of the cooling channel due to the spring-loaded rear housing part. This ensures that the ultrasonic probe is in continuous contact with the side to be measured. The use of a chain forms a flexible but torsionally stiff guiding member, allowing for precise guiding of the probe unit in the cooling channel. Furthermore, the chain can be coupled to an encoder gear, thereby allowing for position measurement of the probe unit in the coolant channel without slippage etc.

[0017] The "length" of a coolant channel is the maximum dimension of the coolant channel. Since the cooling plate is substantially vertical in use, the length may also be referred to as the "height."

[0018] In an embodiment, the housing includes a main housing portion defining a sensor side, and the ultrasonic probe is disposed in an open recess in the sensor side.

[0019] The main housing portion may be formed with a generally semi-cylindrical wall extending between opposite ends; the rear housing portion may be configured as a wall portion having rounded outer and inner sides complementary to opposite sides of the housing portion.

[0020] In an embodiment, the rear housing portion includes at least one, and preferably two, pins that engage respective cavities in the main housing portion, each pin surrounded by a spring that biases the rear housing portion away from the main housing portion.

[0021] In an embodiment, the rear housing part includes lateral branches cooperating with guiding means on the main housing part for guiding the rear housing part. The branches may include fingers engaged in grooves in the guiding means, the grooves defining a sliding axis parallel to the axis of said pin.

[0022] The probe holder unit may be fixed to the drive chain by any suitable means. The fixing means may comprise coupling links at a first side of the housing, in particular coupling links pivotally attached to the housing and including an orifice for connecting the drive chain.

[0023] Advantageously, an articulated stabilizer is pivotally connected to the housing. The stabilizer comprises a set of elements that are articulated to one another and are configured to form a guide housing for the cable assembly. The elements of the stabilizer may be shaped as hollow cuboid- or parallelepiped-shapes that are pivotally and serially connected to one another and define a central passage for the cable assembly. Preferably, the elements of the stabilizer are configured to be pivotable mainly towards the rear side of the housing.

[0024] The use of such stabilizing members provides protection to the cable assembly, which is particularly beneficial for protecting the cables in angled portions of the coolant flow path.

[0025] In an embodiment, the encoder arrangement comprises a mounting frame adapted for mounting on the periphery of a connecting pipe or fitting in communication with the cooling passage and adapted to support a first gear and an encoder. The first gear is located such that at least a portion of its periphery is in axial continuity with the cooling pipe or fitting when the mounting frame is in position on the cooling pipe or fitting. The chain may thus be disengaged from the first gear in direct alignment with the connecting pipe. Preferably, a second gear is provided adjacent the first gear for tensioning the drive chain, the second gear being pivotally mounted on a pivotable arm fixed to said mounting frame.

[0026] The cable assembly may conveniently include a flexible hose for supplying coupling fluid to the probe holder unit. The housing may include an inlet port for the fluid coupling medium and a spray opening on the sensor side, the latter connected by an internal duct. For protection, the wires / hoses of the cable assembly are placed in a flexible steel socket.

[0027] Advantageously, the drive chain is a multi-row chain connected to the probe housing that extends longitudinally within the coolant flow passage, and thus exhibits longitudinal flexibility and torsional rigidity.

[0028] These and other embodiments of the device and method are set out in the accompanying dependent claims. The invention thus provides an improved system for measuring / monitoring the thickness of a cooling plate. The inventive system can use commercially available ultrasonic inspection equipment. The combination of an ultrasonic probe and an encoder structure allows for accurate thickness measurements with respect to the exact position (length / height) of the probe thanks to the encoder. UT measurements can be made continuously along the length of the coolant flow passage or spot-by-spot at multiple predefined positions.

[0029] It is desirable for the system, and especially the probe holder unit, to undergo regular certification to ensure that the system is 100% reliable for measurements. According to another aspect, the invention relates to a method as claimed in claim 16. [Brief description of the drawings]

[0030] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] 1 is a perspective view of an embodiment of a probe holder unit according to the present invention; [Diagram 2] FIG. 2 is a side view of the probe holder unit of FIG. [Diagram 3]FIG. 2 is a top view of the probe holder unit of FIG. 1. [Figure 4] BB cross-sectional view showing the probe holder unit in the rest position (A) and in the compressed position (B). [Diagram 5] FIG. 2 is a cross-sectional view of a cooling plate equipped with the system, with the probe holder unit of FIG. 1 inserted into its cooling channels and an encoder structure attached to the inlet of a connecting tube. [Figure 6] 6 is a cross-sectional view of the encoder structure shown in FIG. 5 along the line AA. [Figure 7] 6 is a cross-sectional view of the encoder structure of FIG. 5 . [Figure 8] FIG. 1 is a principle diagram of the system ready to measure the thickness of a cooling plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The present invention relates to a system and method for measuring the thickness of a cooling plate. The system comprises a probe holder unit 10 designed to be inserted into the coolant / cooling channel of a cooling plate 12 to measure the thickness of the body and ribs remaining on the front side of the cooling panel. The probe holder unit 10 is driven through the cooling channel by a drive chain 14. An encoder arrangement 15 allows the determination of the position of the probe holder unit 10 in the cooling channel. The principle of the system is illustrated in figure 8.

[0032] As is known, cooling plates 12 are used in the steel industry to cool the walls of furnaces, such as shaft furnaces, blast furnaces or electric arc furnaces. A cooling plate typically comprises a body formed, for example, from a cast or forged slab of copper, copper alloys or steel. The body further has at least one conventional coolant passage embedded therein. The coolant passages may be formed by cast tubes or by drilling holes in the body.

[0033] FIG. 8 shows a conventional cooling plate 12 comprising a copper alloy slab-like casting 16 containing a number of coolant channels 18 (only one shown in the figure). The coolant channels 18 are obtained by drilling the casting from one longitudinal end to the other; then drilling top and bottom access holes 16.1 at the ends of the coolant channels 18. The axial ends of the coolant channels 18 are closed by plugs (not visible), while connecting tubes 18.1 are welded to the access holes 16.1. In a blast furnace, such a cooling plate 12 provides a heat rejection protection screen between the interior of the furnace and the outer furnace shell 20 (or armour).

[0034] In a blast furnace, the cooling plate 12 is mounted in the furnace shell. The body 16 has a front surface, also referred to as the hot face, generally indicated at 22, facing the interior of the furnace, and an opposite rear surface 24, also referred to as the cold face, which in use faces the inner surface of the furnace shell.

[0035] As is known in the art, the front surface 22 of the body 16 advantageously has a structured surface having, inter alia, alternating ribs 26 and grooves 28. When the cooling plate 10 is installed in a furnace, the grooves 28 and lamellar ribs 26 are generally horizontally oriented to provide an anchoring means for a refractory brick lining (not shown).

[0036] As is known, depending on the operating conditions of the blast furnace, the protection provided by the refractory lining or the process-generated deposits can be eroded by descending heavy load material, which results in the reality that the cooling plates - at least for a certain period of their life - are unprotected and have to face the harsh environment inside the blast furnace, which results in wear of the cooling plates as well and makes it desirable to know their wear state.

[0037] The symbol 8 indicates. 1, the probe holder unit 10 includes a housing 30 in which an ultrasonic probe is disposed so as to transmit and receive ultrasonic waves. The housing 30 is generally made of a metal, such as an aluminum alloy. As can be seen from the figure, the housing 30 has a generally cylindrical or tubular outer shape (but not necessarily circular in cross section) and is adapted to fit within the coolant flow passage 18 of the cooling panel 12.

[0038] The housing 30 extends from a first end 30.1 to a second end 30.2 along a longitudinal axis L. The housing 30 has a lateral sensor side 30.3 and an opposite back side 30.4. The ultrasonic probe 32 is disposed within the housing 30 such that it can transmit and receive ultrasonic waves from the sensor side 30.4.

[0039] The direction L is the direction in which the probe 10 is actually used. In the illustrated embodiment, the housing 30 comprises two parts or shells. A first housing part includes a lateral housing wall 31 extending between opposite ends 30.1, 30.2 and having a rounded outer surface. This housing part 31 defines a sensor side, which here appears generally as a cylinder side. An ultrasonic probe 32 is disposed in a cylindrical recess 34 in the wall / part 31.

[0040] At the rear side 32.4, opposite the sensor side 32.3, is a second housing part 36, which is movable relative to the first housing part 31 in order to allow the probe holder unit 10 to adapt to the inner diameter of the coolant passage, as will be explained below. The second housing part 36 is formed as an assembled wall in such a way that it is movable relative to the first housing part 31 transversely to the length axis L, usually perpendicular thereto. The movable second housing part 36 has a cylindrical outer surface. In order for the probe holder unit 10 to self-adapt to the inner diameter of the cooling passage 18, the second housing part 36 is spring-biased away from the first part 31.

[0041] In the embodiment shown, the second housing part 36 comprises two lateral branches 36.1, by means of which it is slidably guided in the first housing part 31. Due to these branches 36.1 the movable wall 36 has a sort of U-shaped cross section.

[0042] Reference numeral 38 denotes a core element arranged in the first housing part 31, preferably aligned with the recess 34, in an internal cross section. The core element 38 may have a prismatic shape and projects from the first housing part 31 towards the movable wall 36. It includes a pair of blind bores (not visible) (see FIG. 2) which receive respective pins 40 integral with the movable wall 36. Each pin 40 is surrounded by a compression spring 42 which extends from the inside of the movable wall 36, approximately perpendicular to the longitudinal axis L, and which has one end against the inside of the wall 36 and the other end against the bottom of a blind bore in the core 38. The spring 42 thus exerts an outward biasing force to move the movable wall 36 away from the first housing part 31.

[0043] The movable walls 36 form an expandable structure that automatically deploys / adapts so that the device 10 expands across the entire inner diameter of the coolant passage 18, ensuring intimate contact between the inner surface of the coolant passage 18 and the probe holder sensor side 30.3.

[0044] 4A shows the rest position, with the movable wall 36 at its outermost position. This is essentially the configuration when the probe holder unit 10 is outside the cooling channel or in a large diameter connecting tube. In this configuration, the maximum cross-sectional dimension is Dmax.

[0045] 4B shows a compact configuration of the probe holder unit 10, where the movable wall 36 rests against the first housing part 31. Note that the distance Dmin is now the smallest dimension of the probe unit 10.

[0046] In this embodiment, the branch 36.1 of the movable wall 36 includes an outwardly projecting finger 36.2 which fits into a guide element 44 provided with a groove 46 running parallel to the pin 40.

[0047] Fixing means are provided at the first end 30.1 of the probe holder unit for mounting the drive chain 14. Here, the fixing means comprises a pair of connecting links 48 attached to the first housing part 31. In Figure 1, the links 48 have a first hole 48.1, by means of which the links 48 are pivotally fixed to the first housing part 31, for example by means of a screw. A second hole 48.2 is for connection to the drive chain 14.

[0048] The connecting link 48 defines, by means of the holes 48.1 and 48.2, a pivot direction P corresponding to the centre of the holes, which is perpendicular to the direction L and perpendicular to the pin 40.

[0049] In use, the drive chain 14 is fairly stiff laterally, i.e., it is torsion resistant, whilst providing the desired bending capability (due to its articulation) along the length L. The articulation of the probe holder together with the flexibility of the chain 14 allows it to easily bend 90° after the inner end of the tube. The torsional stiffness of the drive chain 14 allows for its directional control.

[0050] In particular, for increased strength and stiffness, the chain 14 may be a multi-row chain, such as a duplex roller chain having two rows of side links.

[0051] The probe holder unit 10 is connected at the second side 30.2 to an articulated stabilizing member 50. The stabilizing member 50 comprises a set of elements 50.1, 50.2, 50.3, which are articulated to one another and are configured to form a guiding housing for the cable assembly 60. The elements 50.i may be formed as hollow cubic elements defining a central passage 55 in a length direction L from the rear side 52 of the housing 30 to the front side 54 adjacent to the second end 30.2. The elements 52i are pivotally connected to one another so that they can pivot about respective transverse axes A parallel to the axis P. However, the articulation of the stabilizing member 50 is performed on an offset axis - towards the bottom in FIG. 1 - so that the stabilizing member 50 can only be bent downwards, i.e. on the side of the rear side 30.4 and downwards, as indicated by the arrow 56 in FIG. 2.

[0052] Reference numeral 58 denotes a fitting nut threadedly engaged with a cylindrical sleeve that defines an entrance to an internal passageway 55 through the stabilizing member 50. The fitting nut 58 is adapted to attach a cable assembly 60 to the stabilizing member 50. The cable assembly thus enters through the entrance defined by the sleeve 55 at the rear 52 and passes through the internal passageway 55 of the stabilizing member 50 to be connected to the housing 30.

[0053] A pair of openings, not shown, is provided on the end side 30.2 for the input and output wires. In addition, the entrance of an internal fluid duct (for coupling fluid; necessary for US test measurements) opens into a spray hole 62 on the sensor side 30.1. The cable assembly 60 guided inside the stabilizing member 50 can thus include a pair of wires for the sensor signal, which are connected to the probe holder unit 10 via the second end 30.2, as well as a flexible fluid duct. These wires and fluid ducts are advantageously arranged inside a flexible steel sock 60.1.

[0054] In use, the signal cables of these cable assemblies are connected at the other end to a control unit 8 configured to perform reflective ultrasonic thickness measurements, as shown in Figure 8, where the control unit 8 also receives signals from the encoder structure 15. The control unit 8 may be any suitable commercially available ultrasonic inspection controller.

[0055] 5 to 7, a modified version of the encoder structure 15 will now be described. Conventionally, the connecting pipe 18.1 traverses the furnace outer wall 20 through the opening 20.1 and is surrounded by a sealing box 68 including an annular 68.1 flange surrounding the opening 20.1 and welded to the outer wall surface. A metal bellows seal 68.2 surrounds the connecting pipe 18.1 and is attached at one end to the annular flange 68.1 and at the opposite end to a collar 68.3 that fits over and is welded to the connecting pipe 18.1. The bellows seal 68.2 is protected by a metal surrounding sleeve 68.4 attached to the annular flange 68.1.

[0056] Reference numeral 70 denotes a pipe coupler fitted over the end of the connecting pipe 18.1 for connection to cooling fluid distribution piping (not shown).

[0057] The encoder structure 15 includes a mounting frame 72 mounted to a fitting 70 (or alternatively directly to the end of the connecting tube 18.1 where no such fitting is present). The mounting frame is shaped as an open annular member which supports an encoder 74 and an encoder gear 76 (or first gear) coupled thereto. In use, the drive chain 14 meshes with the encoder gear 76 such that forward or reverse movement of the drive chain 14 rotates the encoder gear 76 and the rotation of the first gear is measured / detected by the encoder and a corresponding position / distance is calculated based on the encoder signal.

[0058] In the embodiment shown, the mounting frame 72 includes an inner ring 72.1 surrounded by an outer cover ring 72.2 attached thereto, both of which are formed as open rings. The cover ring 72.2 has a wider opening than the inner ring 72.1.

[0059] The inner ring 72.1 includes three radially extending threaded holes 72.3 which receive three radially extending rods 78. The rods have external threaded surfaces and carry the fitting 70 at one end and are provided with a butterfly at the other end. The rods 78 can be rotated within the holes 72.3 to lock the mounting frame 72 in the appropriate position on the fitting 70, preferably in a central position. Locking nuts 80 are provided on the rods 78 to prevent their movement at the desired radial position.

[0060] The mounting frame 72 supports various elements. Reference 82 denotes a first angle bracket which is integral with the inner ring 72.1 and extends axially outside the circumference of the mounting frame. The encoder gear 76 is rotatably supported on a shaft 84 which projects from the first angle bracket 82. Reference 86 denotes a second tensioner gear which is rotatably supported on a shaft 88 which extends from a pivot arm 90. The pivot arm is L-shaped and is mounted by a pivot 92 to the free end of the first angle bracket 82.

[0061] 5, the pivot arm 90 is shown in solid lines in an operative position, where it is adjacent to the encoder gear 76 to ensure that the drive chain 14 remains in mesh with the encoder gear 76. However, the arm 92 is also shown in dashed lines at a distance from the encoder gear 76; this corresponds to a rest configuration, where the drive chain and probe unit are in a convenient position. The arm 92 can be locked in the operative position by a pin 94 which engages in respective aligned holes in the bracket and arm.

[0062] Reference numeral 96 denotes a second angle bracket which is also fixed at one end to the inner ring 72.1 and which fixedly supports the encoder 74 at its other end. The encoder 74 has an input shaft 74.1 which is substantially aligned with the shaft 84 of the encoder gear 76 and coupled thereto via an encoder coupling 98. The encoder coupling 98 conventionally takes the form of a tubular member with an annular groove which is fitted over the encoder shaft 74.1 and the encoder gear shaft 84 and which provides a torsionally accommodating coupling between the parts.

[0063] Thickness measurement In order to carry out thickness measurement using the probe holder unit 10, the cooling plate 12 is removed in advance from the reactor coolant circuit and the cooling water is emptied therefrom.

[0064] In most cases, only the drive chain 14 is inserted first through the upper connecting tube 18 seen in FIG. 5, down through the cooling passages to the bottom, and further down through and out of the lower connecting tube.

[0065] The probe holder unit 10, together with the stabilizer 50 and cable assembly 60, are then connected to the housing 30 by the link 36. The chain is then pulled to bring the probe unit 10 to the top of the coolant flow passage as shown in Figure 5. The tension gear is then brought to the operating position in Figure 5, which properly couples the chain 14 to the encoder gear 76. From there, measurements can begin. The drive chain 14 is moved / delivered forward and the iron cable sock 60.1 is pulled from the bottom to move the probe unit within the cooling flow passage 18.

[0066] Within the coolant flow passage 18, the probe holder 10 is gradually lowered to take thickness measurements at multiple locations along the length of the coolant flow passage 18. The probe unit 10 is capable of measuring the thickness of the body not only at the inlet and outlet regions of the body, but also at multiple locations along the length of the body and ribs, including the central region.

[0067] In practice, the probe unit 10 is moved to multiple locations to perform thickness measurements at each location along the entire length of the coolant channel. In other words, measurements can be performed at spots (defined local locations) of any desired length / height of the coolant channel. During thickness measurements, the sensor side 30.3 is kept substantially perpendicular to the front side 22. The angular orientation of the probe unit 10 in the coolant channel 18 is known thanks to the configuration of the chain 60 with a flattened cross section.

[0068] It is preferred to use water as the coupling medium, however any suitable coupling fluid / medium can be used (especially if rust is present inside the passages.) The coupling fluid is fed through the cable assembly 60, into the housing 30, and sprayed against the inside surface of the coolant passages 16 by the spray openings 62.

[0069] As can be seen, the probe unit 10 is inserted inside the coolant passage 18 and so measures the body thickness according to the distance from the inside of the coolant passage 18 (facing the front side) to the frontmost body or rib end portion on the front side at the level of the probe holder 10 (i.e. perpendicular to the front side).

[0070] That is, when the probe is at the level of rib 26, the thickness of the body corresponds to the distance from the inner surface of the channel to the tip of rib 22. When the probe is at the level of groove 28, the thickness of the body corresponds to the distance from the inner surface of the channel to the tip of rib 26.

[0071] As known in the art, in reflection (or pulse-echo) mode, the ultrasonic sensor / transducer 32 both transmits and receives pulsed sound waves that are reflected back to the transducer from the interface formed by the front side of the cooling plate 12. The transducer 32 can be of any suitable technology, for example, piezoelectric; when excited, it can emit very short ultrasonic pulse waves, typically with a center frequency in the range of 1 to 15 MHz. The control unit is configured to perform thickness measurements based on the time it takes for the ultrasonic waves to return to the coolant flow path surface. For example, the control unit can be configured to display the results in the form of a signal with an amplitude that represents the strength and distance of the reflection, and that represents the time of arrival of the reflection. The use of ultrasonic waves is not the focus of the present invention, and one skilled in the art can devise other methods of utilizing the transducer signal.

Claims

1. 1. A system for measuring a thickness of a cooling plate, comprising: a probe holder unit (10) designed to fit inside a coolant flow channel (18) of a cooling plate (12), the probe holder unit including a housing (30) extending along a length axis (L) from a first end (30.1) to a second end (30.2) on a lateral, sensor side (30.3) and an opposite, rear side (30.4); and an ultrasonic probe (32) arranged within the housing so as to be capable of transmitting and receiving ultrasonic waves from the sensor side; a rear housing part (36) movably arranged on the rear side, which is elastically biased transversely to the length axis and away from the sensor side, thereby allowing the probe holder unit to adapt to the size of the cooling channel; a drive chain (14) for assisting the travel of the probe holder unit (10) through the length of the coolant flow path, the drive chain being connected to a first connection means (48) at the first end of the housing; a cable assembly (60) including electrical wires connecting the ultrasound probe; an encoder structure (15) configured to cooperate with a drive chain, such as to measure a length of the drive chain passing therealong, the encoder structure including a first gear (76) meshing with the drive chain and coupled to an encoder; A system including:

2. 2. The system of claim 1, wherein the housing includes a main housing portion (31) defining the sensor side, and the ultrasonic probe is disposed in an open recess (34) in the sensor side.

3. 3. The system of claim 2, wherein the main housing portion is formed with a generally semi-cylindrical wall (31) extending between opposite ends; and the rear housing portion is configured as a wall portion having rounded outer and inner sides complementary to opposite sides of the main housing portion.

4. 4. A system as described in claim 2 or 3, wherein the rear housing portion (36) includes at least one, preferably two, pins (40) that engage respective cavities in the main housing portion, each pin being surrounded by a spring (42) that biases the rear housing portion away from the main housing portion.

5. 4. A system according to claim 2 or 3, wherein the rear housing part comprises lateral branches (36.1) which cooperate with guiding means on the main housing part for guiding the rear housing part.

6. 6. The system of claim 5, wherein the branch includes a finger (36.2) engaged in a groove (46) of the guide means, the groove defining a sliding axis parallel to the axis of the pin.

7. 4. The system of claim 1, further comprising a fastening means on the first side of the housing for connecting the drive chain, in particular a connecting link (48) pivotally attached to the housing and including an opening for connecting the drive chain.

8. 4. The system of claim 1, further comprising an articulated stabilizing member (50) pivotally connected to the housing, the stabilizing member comprising a set of elements (50.i) articulated to one another and configured to form a guide housing for a cable assembly.

9. 9. The system according to claim 8, wherein the elements (50.i) of the stabilizing member are shaped as hollow rectangular or parallelepiped shapes pivotally and serially connected to one another and define a central passage for the cable assembly.

10. 9. A system according to claim 8, wherein the elements (50.i) of the stabilizing member are configured to be pivotable mainly towards the rear side of the housing.

11. 4. The system of claim 1, wherein the encoder structure includes a mounting frame adapted to be mounted on an outer periphery of a connecting pipe or fitting communicating with the cooling flow passage and adapted to support the first gear and the encoder, the first gear being positioned such that at least a portion of its periphery is axially continuous with the cooling pipe or fitting when the mounting frame is in position on the cooling pipe or fitting.

12. 4. The system of claim 1, wherein a second gear (86) is provided adjacent to the first gear for tensioning the drive chain, the second gear being pivotally mounted on a pivotable arm fixed to the mounting frame.

13. 4. A system according to any one of claims 1 to 3, wherein the cable assembly further comprises a flexible hose for coupling fluid.

14. 4. The system of claim 1, wherein the drive chain is a multi-strand chain connected to the probe housing and extends longitudinally within the coolant flow path, and therefore exhibits longitudinal flexibility and torsional rigidity.

15. 4. The system of claim 1, wherein the housing includes an inlet port for a fluid coupling medium and a spray opening on the sensor side.

16. A method for measuring the thickness of a cooling plate in a blast furnace by means of a system according to any one of claims 1 to 3, comprising the steps of: Disconnect the cooling panel and empty the water from it; Install the encoder structure to the top connecting pipe of the cooling panel; Feed the drive chain through the top connecting tube into each cooling channel until the chain end exits the bottom connecting tube; attaching the probe unit with the cable assembly to the drive chain with a first connection means; withdrawing the drive chain in the coolant flow path and bringing the probe holder unit to the starting position; The encoder structure measures the travel length of the drive chain. The method includes:

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