Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
  • G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
  • G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
  • G01N21/718—Laser microanalysis, i.e. with formation of sample plasma
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/85—Investigating moving fluids or granular solids
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/85—Investigating moving fluids or granular solids
  • G01N21/8507—Probe photometers, i.e. with optical measuring part dipped into fluid sample

Definitions

• the invention relates to a submersible probe for a device for performing laser-induced plasma spectroscopy in a liquid or solid free-flowing material such as a metallic melt, which submerged probe extending from a foot-side end of the submersible probe about a longitudinal axis thereof with a tubular opening for flowing in material.
• the invention relates to a device for determining a physical and / or chemical property of a liquid or solid free-flowing material such as a metallic melt, in particular for performing laser-induced plasma spectroscopy, comprising a submersible, which from a foot end of the Immersion probe has a longitudinal axis of the same extending tubular portion having an opening for the flow of material, as well as an associated with the immersion probe analysis means with which a property of the material flowing into the immersion probe material can be analyzed.
• the invention relates to a method for determining a physical and / or chemical property of a liquid or solid free-flowing material such as a metallic melt, in particular for performing laser-induced plasma spectroscopy, wherein a tubular portion having an opening immersion probe in the Material is introduced and allowed to flow into this material, wherein properties of the inflowing material are analyzed.
• a determination or control of chemical compositions of liquid or solid free-flowing materials is essential today in many chemical processes and is one of the most important measures of quality control. While in the past samples were taken mainly by hand for this purpose and these were analyzed in an external laboratory, it is nowadays common practice to determine chemical compositions directly on site or in-situ in the material in order to obtain measurement results faster and thus, if necessary be able to intervene regulatively in a process.
• a particularly powerful and therefore attractive method for the determination of a chemical composition of solid or liquid materials is laser-induced plasma spectroscopy (LIPS).
• LIPS laser-induced plasma spectroscopy
• a surface is used of a material to be examined, for example by exposure to a high-energy laser beam ignited a plasma.
• the electromagnetic radiation emitted by this plasma is characteristic of a composition of the material on its surface.
• a chemical composition of the material can in principle be determined very accurately and with little expenditure of time.
• These immersion probes essentially consist of a foot-side open tube in which an overpressure can be generated.
• the tube is closed at its head end and equipped with a gas supply.
• the head-side end has a window through which laser light for igniting and maintaining a plasma can be introduced.
• the window can also emit radiation emitted by the plasma and transmit it to a light-conducting device, e.g. an optical waveguide and subsequently a spectrometer or detector are supplied.
• a focusing device is usually additionally provided in order to focus both a plasma-generating laser beam on a material surface and to collect radiation emitted by the plasma.
• a plasma using a submersible probe within a melt there are two variants to ignite a plasma using a submersible probe within a melt and to analyze its emitted radiation.
• an inert gas is blown through the tubular portion of the immersion probe with such a high pressure that in the region of the introduced immersion probe, a melt level is pressed against a hydrostatic pressure approximately in the region of an end opening of the submersible probe.
• a plasma is ignited and analyzed by this radiation emitted by the emitted radiation after passing through the tubular portion of the submersible probe and its window by means of a light guide Analytical device, in particular a spectrometer, is supplied.
• the tubular portion of a submersible probe is also pressurized, but a pressure is chosen lower and so that a melt level is within the submersible probe or a tubular portion thereof.
• a plasma is ignited on the melt located in the immersion probe and in turn analyzed by this emitted radiation.
• Immersion probes according to the prior art have a number of disadvantages.
• an inert gas due to the long time period required before a measurement for setting a height-stable melt level, it is not always possible to ensure that a melt surface is free of oxide, which can lead to incorrect measurement results.
• a further disadvantage is that, when analyzed on a surface of a melt, which is in surface contact with the remainder of the melt bath, oscillations of the melt surface can not be ruled out, which likewise can lead to falsified measurement results.
• the immersion probe when the immersion probe is inclinedly introduced into a melt, the surface of the melt is inclined relative to a guided along the longitudinal axis of the immersion laser laser beam with which the plasma is ignited, resulting in different measurement results than in a vertical position of the melt surface relative to the laser beam , In this case, therefore, measurement results are highly dependent on the inclination angle of the immersion probe relative to a melt surface, which dependency is scarcely calibratable or correctable.
• the invention has the object to provide a submersible probe of the type mentioned, in which disadvantages of the prior art are eliminated.
• Another object of the invention is to provide a device of the type mentioned, in which the disadvantages of immersion probes inherent in the prior art are at least partially eliminated.
• the first object to provide a submersible probe of the type mentioned, in which disadvantages of the prior art are eliminated, is achieved by a submersible probe according to claim 1.
• Advantageous developments of a submersible probe according to the invention are the subject matter of claims 2 to 20.
• the advantages achieved by the invention are to be seen in particular in that, when used or introduced into a liquid or solid free-flowing material, the material flows in at a constant angle to the longitudinal axis of the immersion probe.
• an inflow direction is fixed relative to the longitudinal axis exclusively by the provided lateral opening and due to a high inflow velocity of the free jet of several meters per second is substantially independent of gravity, it is irrelevant whether the submersible probe perpendicular or inclined to a bath surface or a Surface of a solid free-flowing material is introduced.
• the immersion probe therefore does not need to be rigidly positioned contrary to the known solutions according to the prior art, but can be arbitrarily and in particular also manually immersed in a melt and tilted.
• Another advantage of a submersible probe according to the invention is that during a measurement, a constant material flow through the provided lateral opening is given.
• pure, oxide-free or slag-free melt from a melt bath is always tracked for measurement. Corresponding problems associated with slag or dross are therefore avoided.
• a submersible probe according to the invention lies in the fact that the opening is positioned at a fixed height of the submersible probe, which is why a jet-like introduction of material at a constant height is ensured during a measurement.
• a height of the material surface to be analyzed is constant and problems arising due to a height-varying melt level, e.g. varying distance of a plasma to the focusing device, excluded.
• Yet another advantage of a submersible probe according to the invention is the fact that it allows a measurement under negative pressure.
• Performing laser-induced plasma spectroscopy under reduced pressure has the advantage that higher signal yields are achieved, which in turn has a favorable effect on a signal-to-noise ratio and thus a quality of the measurement or analysis.
• a submersible probe according to the invention is particularly suitable for carrying out pyrometric measurements or for determining a temperature of the melt, since the incoming beam is free of an oxide layer which also disturbs this.
• An angle at which material can be introduced into the tubular section as a free-flowing jet directed to the longitudinal axis can be selected within a wide range and, for example, be 45 ° to 135 °. In order to have particularly simple geometric conditions in a measurement, it is advantageous if the opening is designed so that the angle is approximately a right angle.
• the opening has a rectangular cross section whose shorter sides are parallel to the longitudinal axis.
• the tubular section can basically be designed with an arbitrary cross-section.
• the tubular portion is formed with a circular cross-section. If this is the case, then it is further expedient if the tubular portion is flat on the inside in the region of the lateral opening.
• means for generating negative pressure or vacuum are provided in the tubular portion.
• This may also be necessary in particular when measuring just below a surface of a melt bath and a hydrostatic pressure exerted by the melt is not sufficient to press melt through the lateral opening or the lateral gap.
• At least one further second opening is provided in the region of the foot-side end and the lateral opening lies between the second opening and a head-side end of the immersion probe.
• the at least one further second opening is attached laterally.
• a free cross section of the second opening is greater than a free cross section of the lateral opening.
• the lateral opening is at half height of the tubular portion or higher.
• a component for closing the lateral opening may be used be provided.
• a component for closing the at least one further second opening is provided, since in this case a foot-side inflow of material during a measurement can be prevented, so that subsequently in the immersion probe only material, which by the lateral opening enters as a jet, is accumulated. Accordingly, less material is present after a measurement process in the immersion probe and therefore less material must be emptied.
• a particularly advantageous variant is characterized in that a component is provided in the tubular portion through which alternatively one of the openings can be closed. For example, during a measurement through the lateral opening material flow, whereas an influx of material at the foot end is prevented. Conversely, after a measurement in the immersion probe accumulated material can be blown through a foot-side opening and at the same time further inflow of material is prevented by the lateral opening. It is particularly advantageous in this context if the component can be activated by generating a negative pressure or overpressure in the tubular section, wherein the second opening can be closed by generating a negative pressure. In this variant, the advantages of a measurement under negative pressure as well as a blowout at overpressure explained above are combined with the advantages of closing individual openings during or after a measurement.
• the tubular portion of the submersible probe consists of a ceramic, in particular of silicon nitride.
• the tubular portion consists of a steel, which is preferably coated or provided with a size to increase its durability under conditions of use.
• the tubular section consists of a steel and in the tubular section, a ceramic insert defining the lateral opening is releasably secured.
• This variant is characterized by the fact that it is both cost-effective and designed for a long service life.
• the tubular portion is made in less critical parts of a steel, whereas in the more critical region of the lateral opening is provided a ceramic insert with greater durability.
• a detachable attachment of the insert also has the advantage that it can be easily replaced when worn without the entire immersion probe would need to be replaced.
• a respective filter is arranged upstream of the opening or the openings on the outside.
• tubular portion is removable, especially if the tubular portion is to be used as a disposable element and a new section is to be used for each measurement.
• a submersible probe according to the invention is particularly useful when used in a generic device for determining a physical and / or chemical property of a liquid or solid free-flowing material such as a metallic melt, in particular for performing laser-induced plasma spectroscopy becomes. Accordingly, the further object is achieved by a generic device comprising a submersible probe according to the invention.
• the immersion probe is releasably secured. This allows, for example, to selectively couple several immersion probes according to the invention with a single LI PS device, e.g. For investigation at different points of a process chain, which is highly practical and leads to a cost reduction.
• the procedural aim of the invention finally is achieved in that in a generic method, the material is introduced as a beam and directed at an angle to the longitudinal axis of the tubular portion and carried out an analysis of the material thus introduced.
• a method according to the invention is to be seen in the fact that the material flows independently of an angle of inclination of the immersion probe against a surface of a melt or a flowable material with a constant angle to the longitudinal axis of the tubular portion, which is why Even with variable tilt angle always a constant measurement geometry can be guaranteed.
• a further advantage with respect to laser-induced plasma spectroscopy is that a distance between the focusing device and the generated plasma is also constant, which is why particularly accurate measurement or analysis results can be obtained. This can be done in a particularly simple manner by a plasma ignited within the immersion probe on a surface of the beam and radiation emitted by the plasma are analyzed.
• a negative pressure is applied in the tubular portion during the inflow of the material.
• a desired atmosphere in particular an inert gas atmosphere, can be set, which is advantageous for LIPS.
• tubular section is emptied after flowing in of material and analyzing the radiation emitted by the plasma by applying a negative pressure, so that in a further measurement, the entire volume of the tubular portion can serve to collect material entered.
• the emptying takes place by applying an overpressure in the tubular section.
• FIG. 1 a submersible probe according to the invention
• FIG. 1a a lateral slot of a submersible probe according to FIG. 1;
• FIG. 1b A foot-side end of a submersible probe according to FIG. 1;
• FIG. 2 shows a cross section through a submersible probe according to the invention according to FIG. 1 along the section line H-II in FIG. 1;
• FIG. 3 shows a tubular section of a submersible probe according to the invention with two lateral openings
• Figure 4 A cross section through a submersible probe according to Figure 3 along the section line
• FIG. 5 shows a tubular section of a submersible probe according to the invention with two lateral openings
• FIG. 6 shows a cross section of a tubular section according to FIG. 5 along the section line VI-VI in FIG. 5;
• FIG. 7 a side view of a submersible probe according to the invention
• FIG. 8 shows a cross section through an immersion probe according to the invention according to FIG. 7 along the section line VIII-VIII in FIG. 7;
• FIG. 9 a side view of a submersible probe according to the invention.
• FIG. 10 shows a cross section through a submersible probe according to the invention according to FIG. 9 along the section line IX - IX in FIG. 9.
• FIG. 1 shows a submersible probe 1 according to the invention in a closer view.
• the immersion probe 1 has a tapered end 2, which simultaneously forms the end of a tubular portion 4.
• the tubular portion 4 which may for example consist of a ceramic or a steel, is hollow in the interior and has a lateral opening 5 or a slot through which material such as a melt can enter jet-shaped.
• the tubular section 4 is adjoined by a further tubular section 9, wherein the two tubular sections 4, 9 are connected to one another in a gastight manner by means of a clamping set 10. Both tubular portions extend concentrically to a longitudinal axis X of the rod-shaped submersible probe 1.
• the submersible probe 1 is closed by a permeable window for electromagnetic radiation 8 and subsequently has a free cross-section 7, on which, for example, a light guide LI PS device can connect.
• the immersion probe additionally has gas inlets or gas outlets 11.
• an opening 5 of a submersible probe 1 according to Figure 1 is shown in more detail.
• the opening 5 or the slot is formed with a rectangular cross-section. This is advantageous in that such a cross section causes a surface inflow of material substantially normal to the longitudinal axis X.
• FIG. 1 b an end-side end 2 of a submersible probe according to FIG. 1 is shown enlarged in FIG. 1 b.
• the conically tapered end 2 is substantially closed and has only at its lowest point a small-sized opening 6, through which material entering during a measurement can be blown out or emptied after a measurement.
• the cross-section of the opening 6 is dimensioned such that, during a usual measuring time, melting of e.g. One minute only small amounts of melt can occur or be pressed in due to a hydrostatic pressure and the opening 5 remains free during the measurement.
• FIG. 2 shows a cross section along the section line INI of FIG. 1 and, in addition, partially a melt bath 13, into which a submersible probe 1 dips.
• material or melt enters the immersion probe 1 as a freely flowing jet 12 if a lateral opening thereof lies below a melt surface 14.
• FIG. 1b shows a further second opening 6 at a foot-side end 2 of the immersion probe 1 melt, which is irrelevant for a measurement, however, as this is done on the free material beam 12. Namely, as shown in FIG.
• a plasma is ignited on the free material jet 12 by means of a laser beam 15 which is focused by means of an optical focusing device 16 (alternatively, a plasma can also be ignited by spark discharge). Since the melt flows continuously, the material jet 12 is essentially free of oxidic impurities and a chemical composition determined on the material jet 12 is characteristic for a chemical composition of the melt bath at the height H1. Furthermore, it can be seen from FIG. 2 that a lateral opening 5 is located in the upper half of the tubular section 4. As a result, a sufficiently large internal volume for accumulation of melt is available for a melt entering from below through the opening 6 during a measurement, without the incoming melt reaching the area of a lateral opening 5 and hindering the material jet 12 in its free propagation.
• FIG. 2 shows that a sufficiently large internal volume for accumulation of melt is available for a melt entering from below through the opening 6 during a measurement, without the incoming melt reaching the area of a lateral opening 5 and hindering the material jet 12 in its free propagation.
• FIG. 3 shows in detail a tubular section 4 of a submersible probe according to the invention.
• the tubular portion 4 in this case has two lateral openings 5, 17, wherein the opening located at a greater height 5 is formed in a slot shape and provides for a two-dimensional inflow of a material.
• a component 18 is mounted, which releases the lateral opening 5 upon application of a negative pressure, thus under measuring conditions, whereas the lateral opening 17 is closed.
• penetration of melt in the region of a foot-side end 2 during a measurement is limited, so that a free-flowing material jet 12 can be ensured over a long period of time. This makes it possible to carry out measurements over a longer period of time in comparison with a submersible probe according to FIG. 1 and thus to achieve even greater reliability or accuracy with regard to the analysis results.
• FIGS. 5 and 6 show the same situation as in FIGS. 3 and 4, with the exception that an overpressure is present in the tubular section instead of a negative pressure.
• a lateral opening 5 is closed by the component 18, a side opening 17, however, released or open. This results in any melt that is above the opening 17 being squeezed out of the tubular section 4 or being removed through the opening 17.
• FIGS. 7 to 10 A further variant of a submersible probe 1 according to the invention with a valve function for closing a lateral opening and a further second lateral or foot-side opening is demonstrated with reference to FIGS. 7 to 10.
• a submersible probe 1 shown in end view in FIG. 7 has, in addition to optical components mounted in the cavity 19 of the submersible probe 1, in particular a focusing device 20, a jacket 21 with a bore 22. This bore 22 is connected to a lateral opening 5.
• a foot-side opening of the tubular portion 4 is closed by a plate 23.

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• 2006
  • 2006-05-09 AT AT0079406A patent/AT503539B1/de not_active IP Right Cessation
• 2007
  • 2007-04-30 US US12/300,089 patent/US20090262345A1/en not_active Abandoned
  • 2007-04-30 EP EP07718418A patent/EP2018540A1/de not_active Withdrawn
  • 2007-04-30 RU RU2008148343/28A patent/RU2008148343A/ru unknown
  • 2007-04-30 KR KR1020087029708A patent/KR20090013819A/ko not_active Application Discontinuation
  • 2007-04-30 WO PCT/AT2007/000204 patent/WO2007128014A1/de active Application Filing

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