US3643508A

US3643508A - Device for removing gas and furnace charge probes from shaft furnaces and/or for taking temperature and gas pressure measurements in the interior space of the furnace

Info

Publication number: US3643508A
Application number: US884971A
Authority: US
Inventors: Werner Schneider
Original assignee: Dango and Dienenthal KG; Huttenwerk Salzgitter AG
Current assignee: Dango and Dienenthal KG; Huttenwerk Salzgitter AG
Priority date: 1969-12-15
Filing date: 1969-12-15
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

A lance for removing gas and furnace charge probes from shaft furnaces, and in particular from blast furnaces. The lance is also suitable for taking temperature and gas pressure measurements in the interior space of the furnace. The lance is horizontally movably mounted on a platform and is adapted to be inserted into the charge of the furnace via a stuffing box packing and a shutoff gate valve, both of which are arranged in the furnace wall.

Description

United States Schneider [54] DEVICE FOR REMOVING GAS AND FURNACE CHARGE PROBES FROM SHAFT FURNACES AND/U EUR TAKING TEMPERATURE AND GAS PRESSURE MEASUREMENTS IN THE INTERIOR SPACE OF THE FURNACE [72] lnventor: Werner Schneider, Siegen/Westfalen, Ger

many

[731 Assignees: Dango 8: Dienenthall lliommanrllitgesellschaft, Siegen am Westfalen; Salzgitter Hultenwerk Alttiengesellschaft Salzgitter, Drutte. Germany [22] Filed: Dec. 15, 1969 21 App1.No.: 884,971

[52] US. Cl ..73/344, 73/212, 73/345, 73/4215 A [51] 1nt.C1 ..G01p5/16,G01k 1/14,G01n 1/24 [58] Field ofSearch ..73/344, 343, 198,212,354, 73/201; 254/93 1 Teh. 22, 11972 [5 6] References Cited UNITED STATES PATENTS Mazur..... Kennedy. Small ..73/344 Primary Examiner-Louis R. Prince Assislant Examiner-Denis E. Corr Attorney-Arthur O. Klein [5 7] ABSTRACT A lance for removing gas and furnace charge probes from shaft furnaces, and in particular from blast furnaces. The lance is also suitable for taking temperature and gas pressure measurements in the interior space of the furnace. The lance is horizontally movably mounted on :a platform and is adapted to be inserted into the charge of the furnace via a stuffing box packing and a shutoff gate valve, both of which are arranged in the furnace wall.

9 Claims, 13 Drawing Figures l-lolbrook ..73/211 PATENIED EBZZ I912 SHEET l N 6 INVENTOR: Wnmm SCHNEIDER M Q w Hrronmm PATENTEBFEBZZ I972 SHEET ,2 [IF 6 INVEN70R= SCHNEIDER PATENTKUFEB 22 I872 SHEEI 3 [IF 6 INVENTORI Uemm scuwemm Wm w Ammnsv mmmurmz 1912 3,643,508

WU 0F 6 INVENTOR Wermua S HNUDER BWMMQ Arromev MIENIEB FEB 22 I972 sum m 6 INVENTOR= Wm SCHNEIDER H rwa u av PIEN IE1] F E8 2 2 I912 m 64 0 5 U SHEET E OF 6 INVENT R wemak SCHN WK AwoRNEv DEVICE FOR REMOVING GAS AND FURNACE CHARGE PROBES FROM SHAFT FURNACES AND/OR FOE TAKING TEMPERATURE AND GAS PRESSURE MEASUREMENTS IN THE INTERIOR SPACE OF THE FURNACE BACKGROUND OF THE INVENTION The present invention relates to devices for removing gas and furnace charge probes from shaft furnaces, and in particular, from blast furnaces.

The devices of this invention are also suitable for taking temperature and gas pressure measurements in the interior space of the shaft furnace.

The device of the invention takes the form of a lance which has a double wall construction thereby providing a flow space for a cooling medium which flows through the aforementioned space during the operation of the lance. The measuring lance of the invention is horizontally movably mounted on a platform forming part of the furnace construction and can be inserted into the interior of the furnace, more particularly, into the furnace charge, through an opening provided in the furnace wall. The opening is provided with a stuffing-boxpacking as well as with a gate-type shutoff valve arrangement. The measuring lance is mounted within the stuffing-boxpacking for slidable movement therein. Devices of the abovedescribed type are already known in the art and can also be utilized to take temperature and gas pressure measurements within the interior space of the shaft furnace. These known types of measuring lances are actuated by means of an arrangement comprising an electric motor which moves the measuring lance into or out of the interior space of the furnace via a suitable opening in the furnace wall by means of a wormgear-spindle arrangement. This known type of arrangement requires, however, a relatively large power input. A further drawback of this known arrangement resides in the different expansions that occur in the furnace lining and the furnace wall, causing thereby a shift in the vertical position of the measuring lance which cannot be compensated by means of the prior art construction.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a measuring lance construction for shaft furnaces, in particular for blast furnaces which will avoid the abovedescribed drawbacks.

In particular, it is an object of the invention to provide a measuring lance for shaft furnaces, and in particular for blast furnaces, which has a very simple construction and is simple to operate, in particular to carry out the temperature and gas pressure measurements within the interior space of the furnace and to take gas and furnace charge probes from the furnace .charge. In accordance with the present invention, this object is obtained by providing a guide frame on a platform of the furnace in which there are mounted a plurality of guide rollers which support the measuring lance at its rearward end. The measuring lance is adapted to be reciprocally moved by means of a hydraulic cylinder arrangement mounted in the guide frame. The hydraulic cylinder of the arrangement is actuated by means of a conventional pump which is operatively connected to the hydraulic cylinder and is adapted to pump into it a predetermined amount of hydraulic fluid. The aforedescribed simple hydraulic cylinder arrangement moves the measuring lance into and out of the furnace charge at infinitely variable speeds, which has significant practical ad vantages in carrying out a continuous measuring operation as will be described hereinbelow.

The actual hydraulic cylinder of the arrangement can be advantageously mounted in two different positions in the guide frame and is movable from one to the other by means of a roller-support arrangement. The hydraulic cylinder can be secured in both of its positions by means of belaying pins being inserted into suitable openings provided in the hydraulic cylinder arrangement and in the guide frame. By adjusting the position of the hydraulic cylinder, it is possible to adjust the stroke of the point of the measuring lance within the interior space of the furnace so that it only penetrates the interior space to traverse the normal measuring path. The support arrangement for the measuring lance makes it possible to move the measuring lance from its forward active position to a rearward position on the guide frame in which it can be adjusted and dismantled. The rollers which form part of the support structure for the hydraulic cylinder arrangement facilitates the sliding of the hydraulic cylinder from its forward to its rearward position and vice versa. The hydraulic cylinder is secured into either of the aforementioned two positions by means of the belaying bolts which are inserted into suitable openings. In order to reduce the overall length of the measuring lance installation, the piston rod of the hydraulic cylinder arrangement is connected to the measuring lance at its free end by means of an entraining fork, the: piston rod being thus advantageously offset with respect to the axis of the measuring lance and being arranged parallel thereto, thereby reducing the overall length of the arrangement.

The uneven thermal expansions of the: wall construction and the lining of the furnace, which occur with particular frequency in new shaft furnaces, and cause a vertical shifting in position of the measuring lance, can be compensated by means of the construction of the present invention. The aforedescribed necessary compensating adjustment can be carried out by means of the construction of the present invention, due to the fact that the guide frame, which supports the hydraulic cylinder and the measuring lance is pivotally supported at its rearward end about a horizontal axis and is connected at its forward end to the furnace wall by means of a vertically adjustable member which is supported on the platform of the furnace. in addition thereto, the measuring lance is slidably movably supported on a support dish which is disposed in the opening of the furnace wall, the support dish and the stuffingbox-packing surrounding the same being protected by a support armature which carries a gate-type shutoff valve and the armature supporting this arrangement being vertically slidably adjustable to a limited extent. It has been found to be advantageous to provide the stuffing box with a ring flange, in which there are disposed a plurality of vertically slotted openings. This first ring flange is slidable with respect to a second ring flange abutting against the armature of the furnace wall, sealing rings being disposed between the first and second ring flanges. Connecting bolts connect this arrangement, the connecting bolts being acted on by dish-shaped springs. The connecting bolts extend to the longitudinal vertically slotted holes of the ring flange disposed adjacent to the stuffing box.

The stuffing box supports slidably therein the measuring lance and seals off the portion thereof which extends into the interior space of the furnace from the ambient outer space. The stuffing box is advantageously provided with lubricating conduit means which are connected to an automatic pump which is adapted to urge a lubricating medium through the conduit and onto the periphery of the measuring lance as the same is being introduced into the interior space of the furnace, thereby applying a layer of lubricating medium onto the periphery of the measuring lance. This layer of lubricating medium prevents a seizing of furnace charge on the point of the measuring lance and also prevents the damaging of the stuffing-box-packing during the withdrawal of the measuring lance. In addition thereto, the friction between the measuring lance and the support dish, which is mounted in the armature of the furnace wall, is considerably reduced thereby lowering the power necessary for removing the lance from the furnace. The measuring lance is generally constructed strong enough to withstand and absorb the loads and impacts produced by the descending furnace charge in the shaft oven. As a rule, it is possible to utilize a measuring lance having a circular cross section which can withstand the aforedescribed loads. How ever, in those furnaces in which there is a particular heavy strain of descending furnace charge, which descends at high velocities, it is sometimes preferable to use a measuring lance having an oval cross-sectional shape, respectively, a streamline cross-sectional shape, thereby offering to the descending furnace charge a correspondingly reduced resistance.

The measuring lance is advantageously constructed in such a manner that it can carry out simultaneously gas probes of the interior space of the furnace, as well as temperatureand staticand dynamic-gas pressure measurements. To achieve this purpose there is disposed in the interior of the measuring lance a longitudinally extending discharge pipe, which has two inlet pipelines extending toward the lance point and being offset 90 with respect to each other. These two pipelines serve to take in gas thereby measuring the static and dynamic gas pressures within the interior space of the furnace. There is, furthermore, disposed in the lance point temperature measuring means which are connected with a line extending through the measuring lance, the temperature measuring means being disposed in the sealing cap of the lance point. This sealing cap is removably mounted on the lance point and includes a plurality of downwardly extending gas suction openings through which a stream of gas flows and after passing through the gas suction openings forms a stream of gas which surrounds the temperature measuring means. The aforedescribed arrangement of the temperature measuring means, being mounted in the sealing cap thereby being protected against damage caused by the furnace charge, and furthermore being exposed to the rapidly flowing stream of sucked in gases, makes it possible to obtain a rapid and nonmalfunctioning temperature measurement with the construction of a measuring lance of the present invention.

Finally, it is also possible with the construction of a measuring lance of the present invention to mount, in lieu of the aforedescribed sealing cap, temperature measuring means, and the pipelines for the gas pressure measurements, a small dish in the lance point, which is adapted to remove a small quantity of the furnace charge. This dish is centrally mounted in the gas takeoff pipe of the measuring lance and can be selectively slid into or out of the lance point. In order to avoid chemical reactions taking place in the removed furnace charge probe during its removal and after its removal, the arrangement of the invention is advantageously provided with means for blowing a neutral gas over the furnace charge probe during its removal and thereafter until the furnace charge probe has been sufficiently cooled. In the event there is not enough space available behind the lance to make it possible to slide out the aforedescribed dish, the latter can be replaced by an arrangement which includes a worm conveyor mounted in the lance point for removing the furnace charge probe.

BRIEF DESCRIPTION OF THE DRAWING The invention is illustrated by way of example in the accompanying drawing which forms part of this application, and in which FIG. 1 is a side elevational view of the installation of a measuring lance forming part of the present invention, in which the measuring lance is mounted on the platform of the fur nace;

FIG. 2 is a plan view of the installation illustrated in FIG. 1;

FIG. 3 is a schematic illustration of two possible configura tions of cross sections of the measuring lance;

FIG. 4 is a cross-sectional view of the lance point;

FIG. 5 is a cross-sectional view along line V-V of FIG. 4;

FIG. 6 is a cross-sectional view along line VI--VI of FIG. 4;

FIG. 7 is a cross-sectional view along line VII-VII of FIG.

FIG. 8 is an axial cross-sectional view showing the opening in the furnace wall, the protecting armature with support dish, the shutoff gate valve and the stuffing-box-packing;

FIG. 9 is a front elevational view of the armature illustrated in FIG. 8;

FIG. 10 is a cross-sectional view on an enlarged scale along line X-X in FIG. 9;

FIG. 11 is an axial cross-sectional view of an alternate construction of the lance point in which there is shown a pan for removing furnace charge probes;

FIG. 12 is a plan view of the pan for removing furnace charge probes illustrated in FIG. 1 l; and

FIG. 13 is a cross-sectional view along line XIIIXIII in FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 and 2, the device of the invention which is illustrated therein, includes a platform 1 forming part of the blast furnace construction 2. A double pivot support 3 projects from the platform 1 for supporting one end of the guide frame 5 thereon. An adjustable support 4 projects from the platform 1 and is adapted to support the other end of the guide frame 5. The guide frame 5 is pivotally supported at the furnace wall 2' by means of an arrangement comprising a plate 6 connected to a pair of arms 7 which are pivotally connected to the furnace wall 2'. The blast furnace 2 is surrounded by a furnace wall lining 2'. The guide frame 5 is provided adjacent to the upper pivot 3 of the double pivot support 3 with a pair of guide rails 5', 5". A support plate 12 is secured to the hydraulic cylinder 8 and has mounted at opposite sides thereof a pair of rollers which are movable along the pair of guide rails 5', 5". The pair of guide rails and the hydraulic cylinder 8 are provided with suitable openings (not illustrated) through which a plurality of belaying bolts 11 can be inserted to fix the hydraulic cylinder in two positions, one of which is illustrated in full lines in FIG. 1 and the other one of which is illustrated in dashed lines in FIG. 1. The position illustrated in full lines in FIG. 1 constitutes the operative position of the hydraulic cylinder in the measuring lance, whereas the position illustrated in dashed lines in FIG. 1 illustrates the inactive position in which the various adjustments for the measuring lance can be effected.

The measuring lance 13 is provided at its rear end with a pair of rollers 14, mounted at opposite sides thereof, which are adapted to move within the double-T-shaped longitudinal support 5" of the guide frame 5. An entraining fork I5 is mounted in the vicinity of the rear end of the measuring lance l3 and is connected to the piston rod of the hydraulic cylinder 8. A nonillustrated pump installation is adapted to actuate the hydraulic cylinder 8 by pumping into it a predetermined adjustable quantity of hydraulic fluid, thereby causing the measuring lance to be introduced through the opening 17 in the wall 2' of the blast furnace 2 or to be withdrawn therefrom.

An armature 27 is mounted in the opening 17. This armature is illustrated in detail in FIGS. 8, 9 and 10.

The armature installation in the opening 17 of the furnace wall 2' is illustrated in detail in FIGS. 8, 9 and 10. This armature installation comprises a stuffing box 20. The armature body comprises a plurality of flange rings 21, 22, 23, 24 and 24. The armature installation further comprises an obturating valve member 26 which is pivoted about the bolt 25. Furthermore, the armature installation comprises a supporting dish 27 which is vertically slidably movably mounted between the flange rings 24 and 24. This supporting dish 27 rests on the wall 2' of the furnace and serves to slidably support the measuring lance 13. As can be particularly noted from FIG. 10 of the drawing, the flanged tube 21 having the ring flange 21' is movable relative to the stuffing-box 20 having the ring flange 20'. The bolt 31 extends through a suitable opening of the ring flange 21 and through a longitudinally vertically slotted opening 29 in the ring flange 20'. At the side of the ring flange 21 there is provided a dish-shaped spring 30 which urges the bolt out of the openings in the ring flanges 21' and 20. On the opposite side of the bolt 31 there is provided a nut 32 and washers 33. Between the

ring flanges

20' and 21 there are provided a plurality of sealing rings 34 which are disposed in suitable grooves of the ring flange 21. As the ring flanges 20 and 21' are urged towards each other by means of a tightening of the bolt 31, the sealing rings 34 can either sealingly engage the surfaces of the flange rings and 211', or if they are not urged towards each other with a large enough force, the flange rings 20' and 21 can be slidably moved with respect to each other. As is more particularly illustrated in FIG. 8, there is provided in the stuffing box body a lubricating nipple which leads into the lubricating conduit 36. A lubricating medium, such as lubricating grease, may, for example, be urged through the conduit by means of a nonillustrated pump to the surface of the sealing rings as well as onto the peripheral surface of the measuring lance 13 passing through the stuffing box 20. As can be noted from FIG. 3, the cross-sectional shape of the measuring lance 13 is normally circular. This configuration is illustrated in dot-dash lines in FIG. 3. However, when the loads imparted by the descending furnace charge are very large, then it has been found advantageous to provide a measuring lance having an oval cross-sectional shape 13 as illustrated in full lines in FIG. 3. The arrangement of the lance point of the measuring lance 13 is illustrated in detail in FIGS. 4, 5, 6 and 7. As can be noted from FIG. 4, the lance point comprises an outer pipe member and an inner pipe member 41. An annular hollow space is thus defined between the pipe members 40 and 41. A cooling fluid, such as, for example, water, is adapted to flow through this annular space and thereby cool the measuring lance 13 while it is in operation. A closure member 43 is affixed to the pipes 40 and 41 as, for example, by welding. A separation pipe 42 is disposed in the annular space thereby causing the circulating cooling water to flow in opposite directions as is illustrated by the arrows in FIG. 4. A cross-slotted front plate 44 is secured to the front end of the closure member 43 as, for example, by welding. The front plate 44 is illustrated in detail in FIG. 6. The front plate 44 has mounted on it a threaded neck portion 45 on which the closure cap 46 can be screwed on as is illustrated in FIG. 4. The closure cap 46 is provided with a plurality of gas suction openings 47. A central pipe 49 axially extends to the inner pipe 41. Gases can be sucked out of the interior space of the furnace and through the gas openings 47, whereupon the gas stream travels through the annular channel 48 situated between the central pipe 49 and the inner pipe 41. The

pipe conduits

50 and 51 are disposed in the central pipe 49 and extend along slots of the front plate 44 which are offset by 90 with respect to each other. A third conduit 53 also extends through the central pipe 49 and is connected to temperature measuring means 52 which are disposed adjacent to the plurality of suction openings 47. The temperature measuring means 52 are connected to a wire 54 which extends through the pipe 53. The wire 54 is connected to a nonillustrated temperature indicating means suitably mounted on the outer end of the measuring lance 13 or some other convenient location on the platform I. The downwardly extending pipe 59 is adapted to measure the dynamic gas pressures in the interior space of the furnace. The other pipe 51 is adapted to measure the static gas pressures in the interior space of the furnace. The other two slots of the front plate 44 are sealed off by fireproof masses Similarly, fireproof masses 55 also seal off the open space between the conduits 50, St and 53. Since the temperature measuring means 52 are surrounded by a rapidly flowing stream of gases being sucked out of the fur nace through the openings 47, it is possible with the arrangement of the present invention to obtain a rapid temperature reading.

It is also possible to remove furnace charge probes by means of the measuring lance of the present invention. Thus, it can be noted that the measuring lance may be fitted with a small pan 60 as is illustrated in FIGS. Ill, 12 and 113. This pan as is slidably movably mounted in a closing member 43' as is illustrated in FIG. Ill. The central pipe 49 may be constructed so that it has a slotted connection 61 as is illustrated in FIG. 12. The central pipe 49, which is axially movable, makes it possible to project pan 60 selectively in front of the closing member 43 thereby scooping up a predetermined amount of furnace charge and withdrawing this charge from the furnace by withdrawing the central pipe 49. The pan tit) is provided with a plurality of channels as is illustrated in FIG. 12, through which a neutral gas may be blown, thereby passing over the surface of the furnace charge probe. This neutral gas will prevent chemical reactions from taking place during the removal of the furnace charge probe from the blast furnace.

Although the invention has been illustrated and described with reference to the two preferred embodiments thereof, it is understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

l. An arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, comprising in combination,

shaft furnace wall means having an opening extending therethrough,

stuffing box means operatively mounted on said furnace wall means and defining at least partially a passage to said opening,

a measuring lance selectively reciprocally movably mounted in said stuffing box means for reciprocating movement through said opening,

hydraulic cylinder actuating means operatively connected to said measuring lance for moving it into or out of said shaft furnace through said opening, said hydraulic cylinder actuating means being adjustably fed with hydraulic fluid so as to move said measuring lance at a predetermined rate,

a guide frame supporting said measuring lance for reciprocal movement, and

means for selectively mounting said hydraulic cylinder on said guide frame in either of two preselected positions.

2. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 1, wherein said measuring lance comprises wall means defining a passage in said measuring lance through which a cooling fluid is adapted to flow.

3. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 2, including platform means disposed outside said shaft furnace, said guide frame being vertically movably mounted on said platform means, and said stuffing box means comprising a supporting dish extending into said opening for slidably supporting said measuring lance therein.

4. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 3, including obturating valve means operatively mounted in said stuffing box means and adapted to selectively close said passage, said obturating valve means comprises means for adjusting the position thereof relative to said stuffing box means.

5. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 4, wherein said stuffing box means has conduit means disposed therein for conducting a lubricating medium onto said measuring lance.

6. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim I, wherein said measuring lance has a circular cross section.

7. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim I, wherein said measuring lance has an oval cross section.

8. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 1, wherein said measuring lance has a first pipe axially mounted therein, a closure member having a plurality of gas suction openings being coaxially mounted on said thereby forming a stream of gas flowing past said temperature measuring means.

9. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 1, a closure member having an axial opening being coaxially mounted on said measuring lance, a pipe axially movably mounted in said measuring lance, and a pan removably connected to the front end of said pipe and being adapted to be inserted into the charge in said furnace for removing a furnace charge probe from said furnace.

Claims

1. An arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, comprising in combination, shaft furnace wall means having an opening extending therethrough, stuffing box means operatively mounted on said furnace wall means and defining at least partially a passage to said opening, a measuring lance selectively reciprocally movably mounted in said stuffing box means for reciprocating movement through said opening, hydraulic cylinder actuating means operatively connected to said measuring lance for moving it into or out of said shaft furnace through said opening, said hydraulic cylinder actuating means being adjustably fed with hydraulic fluid so as to move said measuring lance at a predetermined rate, a guide frame supporting said measuring lance for reciprocal movement, and means for selectively mounting said hydraulic cylinder on said guide frame in either of two preselected positions.

6. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 1, wherein said measuring lance has a circular cross section.

7. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 1, wherein said measuring lance has an oval cross section.

8. The arrangement for removing gas and furnace charge probes from shaft furnaces and for taking temperature and gas pressure measurements in the interior of said shaft furnaces, as set forth in claim 1, wherein said measuring lance has a first pipe axially mounted therein, a closure member having a plurality of gas suction openings being coaxially mounted on said measuring lance, a pair of gas conduits extending through said first pipe, said pair of gas conduits having respectively inlet pipe members which extend transversely with respect to the axis of said measuring lance and are offset 90* with respect to each other, and a second pipe extending through said first pipe and having temperature measuring means connected thereto which are disposed proximate to said plurality of gas suction openings through which gas is adapted to be conducted from the interior of the shaft furnace through the measuring lance thereby forming a stream of gas flowing past said temperature measuring means.