Metal making lance with infrared camera in lance head

Abstract

A lance comprising a lance body including a lance head connected to said lance body and comprising a nozzle body having a central strut having bore hole; a camera assembly, such as an optical or infrared camera assembly, received in said bore hole for monitoring the temperature of said lance head or molten heat in which the lance is inserted; and a protective pipe pressurized with a gas disposed in the bore and surrounding said camera assembly.

Claims

1. An oxygen blowing lance comprising: a lance body having an oxygen conduit and cooling water inlet and outlet conduits surrounding the oxygen conduit; a lance head connected to the lance body and comprising a nozzle body, the nozzle body including a central strut defining a bore hole having a closed end, a plurality of nozzles arranged about the central strut, and a plurality of cooling chambers arranged about the central strut, wherein the plurality of nozzles are in fluid communication with the oxygen conduit for discharging oxygen from the oxygen conduit onto a metal bath in a converter vessel, and wherein the plurality of cooling chambers are in fluid communication with the cooling water inlet and outlet conduits; an infrared camera assembly received in the bore hole for monitoring the temperature of the lance head, wherein the infrared camera assembly is spaced at a distance from the closed end of the bore hole, thereby allowing for thermal expansion of the lance head; signal lines connected to the infrared camera assembly for conveying signals from the infrared camera assembly whereby operation of the blowing lance is regulated in response to the signals; and a protective pipe pressurized with a gas and surrounding the infrared camera assembly and the signal lines.

2. The oxygen blowing lance of claim 1 wherein the protective pipe is disposed within the oxygen conduit or one of the cooling water conduits.

3. The oxygen blowing lance of claim 1 further comprising braided wire leads on the infrared camera assembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure is explained more clearly in the following with the help of an illustration that shows an example of an implementation. In detail the figures show:

(2) FIGS. 1 and 1A show the axial section of an oxygen blowing lance,

(3) FIG. 2 an axial section of the lower part of the oxygen blowing lance in accordance with FIG. 1 as an enlarged drawing,

(4) FIG. 3 an axial section of the lower part of the oxygen blowing lance in accordance with FIG. 1 without the lance head and as an enlarged drawing,

(5) FIG. 4 an axial section of the upper part of the oxygen blowing lance in accordance with FIG. 1 and as an enlarged drawing,

(6) FIG. 5 the cross section of die oxygen blowing lance along the line B-B in FIG. 4, and

(7) FIG. 6 cross section of the oxygen blowing lance along the line C-C in FIG. 4.

(8) FIG. 7 shows an axial section of the lance with thermocouple disposed in cooling conduit instead of oxygen or delivered fluid conduit,

(9) FIGS. 8 and 9 show an axial section of the lance with camera assembly disposed in the central oxygen or delivered fluid conduit of the lance.

(10) FIGS. 10 and 10A show an axial section of an oxygen blowing lance with an IR camera assembly disposed in the central oxygen or delivered fluid conduit of the lance.

DETAILED DESCRIPTION

(11) The oxygen blowing lance shown in FIGS. 1, 1A and 2 is made up of a shafted lance body 1 and a lance head 2 which is welded onto the body. For safety reasons, with awareness of the oxygen processing gas that is flowed through the lance, the lowest part of the lance head 2 is made from copper. Another reason for making the decision to use copper as the material for the lance head 2 is the good thermal conductivity of copper which makes it possible to effectively cool the lance head 2 with cooling water during blowing.

(12) The lance head 2 comprises a nozzle body 2a, made of copper, with a crown of a total of six evenly spaced nozzles 3 and 4 in a circle and simply directed outwards, cooling chambers 5, 6, 7, 8, 9 and 10 as well as a central, axial strut 11. Coaxial, tubular fittings 2b, 2c, and 2d, are connected to the outermost cooling chambers which together with the nozzle body 2a form an interchangeable modular unit.

(13) The lance body 1 consists of three coaxial tubes 12, 13 and 14 made from steel. Together with the incoming/feed connection piece 12a the inside tube 12 forms a central supply line 15 for the oxygen to be supplied to the blowing nozzles 3 and 4. A close sliding fit for 12a is provided in the upper area between the inside pipe 12 on the inside and the middle and outside tubes 13 and 14 which together form a single unit, on the outside. This close sliding fit at 12a serves for adjustment of the relative linear expansions between the tubes 12, 13 and 14 and the assembly of the lance body 2. Conduits 16 and 17 are developed between the inside tube 12 and the outside tube 14 as well as tube 13 that lies in between them. Of these conduits, the inside conduit 16 is the supply conduit and the outside conduit 17 forms the outlet conduit for the cooling water that is to be forced through the channels under high pressure. The cooling water is brought in and let out via laterally placed fittings 18 and 19.

(14) In the central strut 11 of the nozzle body 2a there is a bore hole 20 into which an engaging and disengaging, rod-shaped thermoelectric couple is plugged in as the temperature probe 21. The temperature probe 21 is centered by an adapter 22 and held with its end in contact with the floor of the bore hole 20, which is recessed just a few millimeters opposite the front end 11a of the nozzle body. The adapter 22 is fastened with screws to the inside of the nozzle body. The temperature probe 21 is movable and stored in the adapter 22 and forced towards the floor of the bore hole 20 by a spring 23 that is supported on a regulating screw 25 screwed into the adapter 22. O-rings 25a seal off the central protective pipe 27 from oxygen supply tube 12 and oxygen conduit 15. Signal lines 26, which are installed in a central protective pipe 27, go out from the temperature probe 21. The lower end 27a of the protective pipe and the upper end 22a of the adapter 22 form a sealed, telescopic sleeve which makes it easier to switch out the lance head 2 and allows for various linear expansions of the approximately 20 meter long pipes 27 and 12.

(15) The protective pipe 27 is kept centered at several axially distribute places on the inside walling of the inside tube 12 using springed, radial supporting elements 29 which allow for relative axial motion of the protective pipe 27 compared with the tube 12. The protective pipe 27 is attached directly to the tube 12 only at the top with radial struts 30 and scaled free from tube 12 and open to the atmosphere.

(16) Because of the close sliding fit 12a with potential axial movement of the inside tube 12 and the middle as well as the outside tubes 13 and 14, to fit the lance body 1 with a new lance head 2, the regulating screw 25 is first screwed into the adapter 22 with the rod-shaped temperature probe 21. By doing this the adapter 22 is already preassembled on the inside of the nozzle body 2a so that the temperature probe 21 sits securely in the bore hole 20 after the regulating screw 25 is screwed in. The nozzle body 2a is then connected with its fitting 2d to the inside tube 12 on the point of separation 31 and welded on. In this way the middle and the outside tubes 13 and 14 are pushed back on to the inside tube 12 and the middle tube 13 respectively. Finally, the middle tube 13 and the outside tube 14 are brought close to the fittings 2b and 2c, where the middle tube 13 overlaps the fitting 2c with a close sliding fit and the outside tube 14 is welded on. The removal of a worn out lance head 2 is done in reverse sequence.

(17) The special advantages of the disclosure are that the temperature is monitored at the places of an oxygen blowing lance which are critical with regard to a release of water, that is the front end 11a of the nozzle body that lies opposite the sensor focal point. In this way counteractive steps can be taken with as little delay as possible when there is the threat of a rupture, whether it be due to the mechanical wear and tear of the remaining wall thickness of the cooling chamber, or due to weakening of the chamber walls because of high thermal peaks when there is insufficient cooling during dismantling. Because of the practically immediate determination of the actual temperature it is also possible to consider the temperature over time when choosing what measures to take to avoid a rupture can be counteracted. Finally, it is an advantage that it is not only possible to protect the actual oxygen blowing lance from ruptures but that it is also possible to influence the factors which have an effect on temperature determination and on the regulation of the metallurgical treatment such as the inflow of oxygen, the distance of the lance head from the surface of the molten metal bath etc., to positively influence the refinement process. If for example a temperature is taken that falls far below the critical limit for a lance to rupture, a targeted reduction in the distance between the lance head and the surface of the molten metal bath is possible, through which the refinement process is accelerated and made more efficient.

(18) FIG. 7 shows that the thermocouple 21 may preferably be installed in inlet cooling fluid conduit 16 in the same manner as described above for installation in the oxygen or delivered fluid conduit 15.

(19) Advantages of the present disclosure include: spring-loaded thermocouple 21 inserted into tip to remain in contact with face of lance tip when it expands during service. Spring-loaded thermocouple or standard thermocouple 21 can be used in both the water passages and/or oxygen passage. Modified center post 11 to allow mounting of thermocouple 21 and sealing glands. Free-floating thermocouple pipe 27 sealed by o-rings 25a. Thermocouple 21 can help with measurement of lance height by providing operating data. Thermocouple 21 can be used to provide temperature of copper tip in help determining wear and service life of tip. Thermocouple 21 can help with process temperature throughout the steel melting process by providing reading throughout the heat. Use of braided wire leads on Thermocouple 21 to allow for thermal expansion and ease of installation into lance and repair of lance. Thermocouple 21 is housed and sealed from oxygen and water in its own pipe 27 by o-rings 25a. Thermocouple pipe 27 can be pressurized for puncture or leak detection. Thermocouple 21 can be embedded in tip material, exposed to oxygen flow, exposed to water flow, or exposed to furnace atmosphere.

(20) Similarly to having a thermocouple 21 installed in the lance 1, as shown in FIGS. 8 and 9 a camera assembly 50 and lens assembly 54 with lens 56 (such as those available from Enertechnix) preferably may be installed in lance 1 within protective camera pipe 52, the lower end of which corresponds to the central strut 11. The camera assembly 50 preferably passes through the oxygen or delivered fluid conduit as shown in the drawings and again is movable and preferably forced towards the floor of the bore hole by a spring 55 in the camera or laser assembly 50. Signal lines 57 installed in a central protective pipe 52 go out from the camera assembly 50. Preferably, camera assembly 50 may be installed in either cooling fluid conduit 16, 17 in the same manner as described above for installation in the oxygen or delivered fluid conduit. Also, the camera assembly 50 including lens 56 may be purged with nitrogen or argon gas through the camera pipe 52. Camera assembly 50 and/or camera pipe may be reinforced with ribs.

(21) Camera assembly or optical instrument 50 provides for gathering/taking photos, videos and/or other optical based measurements such as spectroscopy or information from inside the furnace or molten heat in which the lance 1 is inserted.

(22) As shown in FIGS. 10 and 10A, another preferred embodiment of the present invention is shown. The oxygen blowing lance 100 shown in FIGS. 10 and 10A is made up of a shafted lance body 101 and a lance head 102 which is welded onto the body 101. For safety reasons, with awareness of the oxygen processing gas that flows through the lance 100, the lowest part of the lance head 102 is preferably made from copper. The utility of copper as the material for the lance head 102 is significant because copper has good thermal conductivity which makes it possible to effectively cool the lance head 102 with cooling water while the lance 100 is in use.

(23) The lance head 102 comprises a nozzle body 102a, preferably made of copper, with a crown of preferably six preferably evenly spaced nozzles 103 and 104 provided in a radial orientation and directed outwards, cooling chambers 105, 106, 107, 108, 109 and 110 as well as a central, axial strut 111. Coaxial, tubular fittings 102b, 102c, and 102d are connected to the outermost cooling chambers 107, 108, 109, 110, which together with the nozzle body 102a form an interchangeable modular unit.

(24) The lance body 101 comprises three coaxial tubes 112, 113 and 114 preferably made from steel. Together with an incoming/feed connection piece 127, the inside tube 112 forms a central supply line 115 for oxygen to be supplied to blowing nozzles 103 and 104. A close sliding fit for tube 112 is provided at sliding connection piece 112a at an upper area between the tube 112 on an inside portion of the lance 100 and the middle and outside tubes 113, 114, the tubes 113, 114 together forming a single unit on an outside portion of the lance 100. This close sliding fit at connection piece 112a serves for adjustment of the relative linear expansions between the tubes 112, 113 and 114 that occur in the lance 100. Conduits 116 and 117 are developed between the inside tube 112 and the outside tube 114 as well as tube 113 that lies in between them. Of these conduits 116, 117, the inside conduit 116 is a supply conduit 116 and the outside conduit 117 forms an outlet conduit 117 for the cooling water that is to be forced through the conduits 116, 117 under high pressure. The cooling water is brought in and let out of the conduits 116, 117 via laterally placed fittings 118 and 119.

(25) The central strut 111 of the nozzle body 102a defines a bore hole 120 whereby an IR camera 121 may be installed in the lance 100 to view the back side 130 of the nozzle body 102a. The IR camera 121 is centered by an adapter 122. Notably, the IR camera 121, unlike thermocouple 21, will not be held in contact with the bottom of the bore hole 120. This allows for thermal growth that occurs between the various components of the lance. The adapter 122 is welded to the inside of the nozzle body 102a and screwed to the o-ring gland 125a. The o-ring gland 125a, with attendant o-rings 125, seals off the central protective pipe 127 from the oxygen supply line 115. Signal lines 139, which are installed in a central protective pipe 127, go out from the IR camera 121. The lower end 127a of the protective pipe 127 and the upper end 122a of the adapter 122 form a sealed, telescopic sleeve which makes it easier to switch out the lance head 102 and allows for various linear expansions of the approximately 20 meter long pipes 112, 127.

(26) The protective pipe 127 is kept centered at several axially distributed places on the inside walling of the inside tube 112 using spring-biased, radial supporting elements 129 which allow for relative axial motion of the protective pipe 127 compared with the tube 112. The protective pipe 127 is attached directly to the tube 112 only at the top with radial struts 140 and scaled free from tube 112 and open to the atmosphere.

(27) Advantages of the present disclosure include an IR camera 121 inserted into a lance head 102 to monitor the back face of the nozzle body 102a when it expands during use. Further advantageous is the modified protective pipe 127 to allow mounting of an IR camera 121 and o-ring glands 125a, which seals off the free floating pipe 127 with o-rings 125. The IR camera can further be used to measure the height of the lance 100 by providing operating data. The IR camera can be used to monitor the temperature of the nozzle body 102a at the tip of the lance in order to determine wear and service life of the nozzle body 102a. Moreover, the IR camera 121 can help with process temperatures throughout the steel melting process by providing readings throughout the heat. Use of braided wire leads 139 with the IR camera 121 allows for thermal expansion and ease of both the installation of the IR camera 121 into the lance 100 and also the repair of the lance 100. The IR camera 121 is housed and sealed from oxygen and water in its own pipe 127 by the o-ring gland 125a. The IR camera 121 can be pressurized for puncture and leak detection.

(28) In order to replace a deteriorated lance head 101 quickly, the IR camera 121 is secured with the disconnectable adapter 122, which is secured inside the lance 100.

(29) The IR camera 121 does not need to be in contact with the surface of the bore hole floor, and is instead spaced by distance from the closed end, thereby providing for distance variability between the IR camera 121 and the lance head 101 to accommodate thermal growth and change outs of the lance head 101. Spring loaded thermocouples, on the other hand, have a limited range in which the spring can adequately maintain the thermocouple in contact with the lance head 101 tip, and thermal growth can cause a range of motion that is greater than the spring can accommodate. By contrast, the IR camera 121 has a very large range of motion in which it will continue to register the temperature of the lance tip, thereby negating the detrimental effects of thermal growth. Additionally, whereas the thermocouple is known to be limited to registering temperature at a small point of contact in the lance head 101, the IR camera 121 registers an average temperature across its entire field of view allowing for a more accurate measurement.

(30) As shown in FIG. 10, the IR camera 121 is provided at a distance from the back face of the nozzle body 102a, the distance preferably ranging from 20 mm to 2200 mm. The field of view (i.e., the diameter of the field in which the IR camera 121 can detect infrared radiation) of the IR camera 121 preferably ranges from 2 mm to 22 mm. The diameter of the field of view is proportional to the distance between the IR camera 121 and the back face of the nozzle body 102a. For example, when the IR camera 121 is set 20 mm away from the tip it will register a temperature over a 2 mm diameter. When set 2200 mm away, the IR camera 121 will register a temperature over a 220 mm diameter.