DE102004004241B3 - Hand held lance or probe for temperature measurement with a portable optical display - Google Patents

Abstract

The lance has a guide tube (8) for directly or indirectly conveying optical signals recorded from a cast or smelter to an optical display unit which can be worn or carried by the user. Preferably, an unclad glass fiber passes through the guide tube and can be dipped into the smelt at the smelt end of the tube. Independent claims also cover a measuring device having such a probe or lance.

Description

The The invention relates to a hand lance. Moreover, the invention relates a measuring device for the Temperature measurement of a melt, in particular such a device, that in small and medium sized companies for temperature control the usually produced in small batches and treated melts is used.

For example, it is out for large-scale industrial metal production DE 35 21 190 A1 It is known to measure the temperature radiation for the exact temperature determination of the molten steel of a converter. For this purpose, a radiation meter is connected to one end of a channel. The other end of the channel is formed as an integral part of the converter, for example as the bottom of the converter.

Next the big industrialist Metal production using large, automated equipment under constant surveillance in big crucibles Standard metal alloys are manufactured, has become a specialized Industry of small and medium enterprises established in small Batches mostly as contract work to produce special alloys. These companies are increasingly subject to the demand for better economic efficiency, which is particularly the case with energy-intensive Production of metal products improved temperature control in means all fusion metallurgical process steps. An essential one requirement for Such an improvement is the exact knowledge of the current thermal State of the molten metal.

Currently, in these small and medium-sized foundries, the current thermal state of the molten metal is determined by hand lances, at the end thermocouple probes are arranged, which are immersed with the hand lance in the melt and burn there (see. DD 216 531 A1 ). Due to the short service life of the probe, however, the measured value is only available for a short time and can only be assigned to a current process status. To extend the life of the immersed thermocouple probes ceramic thermowells are used, however, extend their own heat capacity, the settling time of the probes or even have only a limited life. Such Kapselthermoelemente are unsuitable for rapid detection of the current thermal state of the molten metal.

In front In this background, the invention is based on the problem, a measuring device for to create the temperature measurement of a melt, which is both a rapid detection of the current thermal state of the molten metal as well as a longer one Allow measuring period.

This Problem is solved by the devices of the independent claims. advantageous embodiments are in the subclaims specified.

The The invention is based on the basic idea, partly of a large industrial one Systems now known optical temperature measurement of a melt now for smaller ones and medium foundries can be used to do that by the big industrialists Equipment usual size equipment expense for such optical temperature measurements is reduced and a mobile measuring device is created. As a result, the in terms of their space requirements of The known with thermocouple probes hand lances continued with simultaneous Provision of a possibility for continuous temperature measurement with fast acquisition times.

The has measuring device according to the invention a hand lance with a guide tube on, brought by the operator to the melt and preferably kept at a distance from the melt or in a holding device is inserted. The guide tube directs optical signals picked up by the melt directly or indirectly to an optical evaluation unit and is for the operator of Measuring device portable and thus formed well movable.

Especially by the support and movable design of the guide tube according to the invention for the first time an optical measuring device created that meets the requirements small and medium-sized foundries does justice. The measuring device according to the invention can due to the portable and movable design of the guide tube easily brought to the melt become. Despite the use of an optical temperature measurement must the operator but not thanks to the measuring device according to the invention huge equipment and structural disadvantages of the large-scale industry known optical temperature measuring devices in purchasing. Rather, the measuring device according to the invention be carried away easily and stored separately. In order to be through the measuring device according to the invention the already cramped spatial conditions of smaller or medium-sized foundries not by further stationary equipment constricted. This leaves the Access to the melt and the handling of the crucible by the use of optical temperature measurement unhindered.

According to the invention directs the guide tube of the melt recorded optical signals directly or indirectly to an optical evaluation unit on. As direct forwarding is understood to be the formation of a channel in the guide tube, the a melting-side end and an evaluation unit facing has another end. The melted end can be replaced by a fixed vitreous body be closed and / or free by blowing inert gas penetrating particles are kept. This channel derives from the melt emitted beams to the optical evaluation unit further, from the spectrum of the rays and previously determined Reference values determines the temperature of the melt.

Prefers However, the indirect forwarding of the optical signals. this includes becomes one through the guide tube guided optical conductor, preferably a glass fiber understood. This in the guide tube provided optical conductor passes in the preferred embodiment the beams continue to the evaluation, so that the optical Ladder holding guide tube the optical signals only indirectly, namely by the provided in it optical fiber passes on to an optical evaluation unit.

Either in the direct, as well as in the indirect forwarding can the evaluation unit spaced from the guide tube and can between the guide tube and the evaluation unit further elements may be provided.

For the indirect Forwarding the optical signals are particularly preferably glass fibers used. these can stationary held in the guide tube and preferably protruding at the melt-side end of the guide tube be so that they are submersible in the melt.

Especially Preferably, glass fibers are used which are encased. For example the glass fiber is sheathed with a stainless steel. Especially preferred however, a conventional, conventional glass fiber used. As a result, the by the stainless steel casing incurred high costs and the heavy to be controlled changes the molten metal quality avoided by the melting stainless steel jacket. For example can be a glass fiber of the type gradient index multimode glass fibers be used.

The Glass fiber is preferably immersed in the melt. hereby If the glass fiber and possibly its sheath is consumed, so that the glass fiber is used as a wearing part. These -wearing Glass fiber can be continuously tracked. The settling times are low due to the direct contact between glass fiber and melt.

When supporting and movable trained guide tubes are in particular such guide tubes understood by the operator of the measuring device easily can be kept and the decoupled from holding devices at the crucible free can be moved and removed from the crucible. As a result, the measuring device, for example stored separately from the crucible and only for use be brought to the crucible. Preferably, the Guide tube or one with the guide tube provided hand lance, fasteners, with which he / she held on a holder of the crucible in a measuring position can be attached.

Especially Preferably, the guide tube or the hand lance, however, designed so that they held completely freehand can be. This training according to the invention the measuring device allows the guide tube or the hand lance For example, pistol-like train. Particularly preferred is the guide tube or the hand lance with a handle that carries, holding and moving the guide tube or the hand lance simplified.

Especially Preferably, the measuring device according to the invention has a fiber tracking, with which the glass fiber can be moved through the guide tube. Investigations by the applicant have shown that particularly good Measurement results are achieved when the glass fiber used wear, so immersed in the melt and, in particular for the provision continuous measurements, tracked. The tracking is especially designed so that the fiber cross-section is not compressed and strong tensile stresses of the fiber will be avoided.

Especially preferred are the guide tube and the fiber tracking as one for formed the operator of the measuring device portable and movable hand lance.

Especially preferred is the fiber tracking directly to the melt remote from the end of the guide tube formed adjacent. This is the idea of good handling one for small and medium-sized foundries compact trained measuring device continued. Alternatively, the fiber tracking can be completely separated from the guide tube educated and in proportion to the guide tube stationary and spaced from the crucible.

The fiber tracking can in particular by at least one with the glass fiber in contact Standing guide roller cause the movement (tracking) of the glass fiber. Particularly preferably, the glass fiber is guided in the fiber tracking in the gap between two opposing guide rollers. As a result, an exact tracking of the glass fiber can be achieved in a particularly advantageous manner. Alternatively or additionally, the fiber tracking can work according to the compressed air principle. For this purpose, a chamber with a purge gas connection is particularly preferably provided in the fiber guide. The glass fiber is driven by means of the purge gas volume flow through a channel in the guide tube.

Especially preferred is one of the guide rollers driven. This powered guide roller or another leadership can be movable in the fiber tracking be configured to adjust the contact pressure on the glass fiber. Particularly preferred is at two opposite each other provided guide rollers the one leadership as a driven drive roller and the other as a pressure roller with adjustable contact force formed.

In a preferred embodiment is at least one of the leadership roles a rubberized roll. Rubberized rollers are particularly good, to the tracking the glass fiber necessary shear forces on the perimeter of the glass fiber applied.

In a preferred embodiment are the leadership roles in a chamber of the fiber tracking arranged. Particularly preferably, the chamber may have a purge gas connection exhibit.

Around premature erosion of the glass fiber in the fiber feed, in particular within the fiber tracking and in the guide tube To avoid the intended channel, the guide tube with the help of a supplied Protective gas stream (preferably argon) cooled. With the help of this construction were for different Glass fiber suitable feed rates in the range of 1 m / min to 6 m / min determined.

In a preferred embodiment the glass fiber between two oppositely rotating and spring-mounted metal discs promoted. Soft rubber bands can protect the glass fiber the metal discs are raised. The contact pressure between the Both drive rollers can be individually adjusted to the outer diameter of the Be tuned fiberglass. Preferably, the entire mechanics in a pressure-tight housing assembled. about a connection piece, the housing can be purged with inert gas. The inert gas leaves the case on Exit the fiberglass and can there for cooling and rinsing the guide tube be used. In the entry area of the glass fiber, the housing can over a O-ring seal to be sealed against the environment.

Especially Preferably, the feed rate for adaptation to the current measuring situation are continuously adjusted. Especially Preferably, the feed direction can be reversed. This can the fiber can also be withdrawn during measuring operation.

Preferably, the maximum to be set pressing force F _{N, max of} the pressure roller is designed according to the following relationship F _{N, max} / L <R _{N, max} .

At this time, the effective length of the pinch roller circumference L is calculated by the following relationship L = (r · π · R) / 180 °

there denotes r the radius of the pressure roller. β is the angular range of the non-positive guide of Glass fiber and is usually assumed as β = 10 °.

R _{N, max} is the transverse compressive strength of the glass fiber and results from the manufacturer's specifications for the glass fiber. Particularly preferably, R _{N, max} = 50 N / cm is assumed.

Especially Preferably, the fiber tracking a fiber consumption counter on. This can be particularly preferably designed as an electronic fiber consumption meter. Alternatively, the fiber consumption via the rotation of a the fiber in contact roller, particularly preferred a leadership role, be determined.

In a preferred embodiment has the guide tube on the melt side a replaceable lance tip. This spearhead can be immersed in the melt and - for example, in case of wear - easy be replaced without that guide tube must be renewed.

following The invention will be explained in more detail with reference to a drawing, which is a preferred embodiment of the invention.

The hand lance shown in the single figure has a guide tube 8th with a replaceable lance tip 9 on. To the guide tube 8th then there is an automatic fiber tracking 1 intended. The automatic fiber tracking has rubberized guide rollers 2 . 3 on. The rubberized leadership 2 is designed as a drive roller. The rubberized leadership 3 is as a pressure roller designed with adjustable contact force. The leadership roles 2 . 3 are in a chamber of fiber tracking 1 educated. This chamber has a purge gas connection 6 with a control valve on. Inlet side of the fiber tracking 1 For example, on a fiber delivery tube, a combined O-ring and labyrinth seal is used 5 intended. The hand lance has a handle 7 on.

As part of the automatic fiber tracking is also an electronic fiber consumption meter 4 intended.

For continuous temperature measurement of a melt in a usual for a small or medium casting crucible is a glass fiber through the insertion tube, the fiber tracking 1 and the guide tube 8th guided. The fiberglass, not shown, is submersed in the melt projecting on the molten side end of the guide tube. The guide tube is carried by the operator on the carrying handle 7 grabbed and carried to the crucible. There the hand lance is held by the operator and immersed in the melt at the molten end of the guide tube protruding fiber. The operator can optionally activate automatic fiber tracking or adjust the fiber tracking itself by means of a regulator. For example, the controller may be provided on the handle in the manner of a gun trigger. Alternatively, the pistol-like trigger can be provided as an on / off switch for automatic fiber tracking.

The glass fiber immersed in the melt takes optical signals of the Melt (the radiation of the glowing Melt) and passes them to an evaluation device, not shown, preferably a pyrometer, continue. There is due to in the Evaluation unit stored reference values from the recorded and relayed optical signals, the temperature of the melt determined. For the In particular, preliminary investigations will be based on publication by Pauly, H .; Engel, F .: The Pyrometer Compendium, first edition, Frankfurt am Main, 1999, referenced.

Claims (11)

Hand lance with a guide tube ( 8th ) for the direct or indirect forwarding of recorded by a melt optical signals to an optical evaluation unit, which is designed to be portable for the operator. Hand lance according to claim 1, characterized in that a sheathed glass fiber through the guide tube ( 8th ) and at the melt-side end of the guide tube ( 8th ) is protruding into the melt immersed. Hand lance according to claim 1 or 2, characterized by a fiber guide ( 1 ) for moving a glass fiber through the guide tube ( 8th ). Hand lance according to claim 3, characterized in that the fiber tracking ( 1 ) directly to the melt remote from the end of the guide tube ( 8th ) is formed adjacent. Hand lance according to one of claims 3 to 4, characterized in that the glass fiber in the fiber tracking ( 1 ) in the gap between two opposing guide rollers ( 2 . 3 ) to be led. Hand lance according to claim 5, characterized in that one of the guide rollers ( 3 ) is driven. Hand lance according to one of claims 5 or 6, characterized in that one of the guide rollers ( 2 . 3 ) is a rubberized roll. Hand lance according to one of claims 5 to 7, characterized in that the guide rollers ( 2 . 3 ) in a chamber of the fiber tracking ( 1 ) are arranged and the chamber a purge gas connection ( 6 ) having. Hand lance according to one of claims 3 to 8, characterized in that the fiber tracking ( 1 ) a fiber consumption counter ( 4 ) having. Hand lance according to one of claims 1 to 9, characterized in that at the molten end of the guide tube ( 8th ) a replaceable lance tip ( 9 ) is provided. Measuring device with a hand lance after one of claims 1 to 10.