JP7115323B2 - Gas sampling pipe and gas sampling method - Google Patents

Description

The present invention relates to a gas sampling tube and gas sampling method.

A gas sampling tube is sometimes attached to a vessel, such as a furnace, in which the inside of the vessel becomes hot, in order to sample and analyze the gas inside the vessel. Such gas sampling pipes are sometimes fitted with filters to collect dust contained in the gas. Patent Literature 1 listed below describes a technique for blowing gas into a sampling pipe and periodically brushing off dust from the filter to prevent clogging of the filter.

However, in the technique described in Patent Document 1 below, when the dust contains molten metal or when the dust concentration is high, blowing off the dust by blowing gas is not enough, and the filter itself needs to be continuously renewed. may become.

On the other hand, Patent Literature 2 below describes a technique of attaching a filter having self-peeling ability to the inside of a gas sampling pipe. That is, a technique is disclosed in which, when molten metal dust adheres to a filter, the dust is peeled off along with the very surface layer of the filter, and the filter is pushed out from the inside of the pipe to renew the filter.

JP-A-2002-139409 JP-A-10-90139

However, even in the technique described in Patent Document 2, there is a problem that the filter is not updated appropriately. That is, since the filter is provided inside the gas sampling pipe, if molten metal dust adheres to the gap between the gas sampling pipe and the filter, the filter cannot be properly renewed.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems. To provide a new and improved gas sampling tube which can be performed systematically.

In order to solve the above problems, according to one aspect of the present invention, there is provided a gas sampling pipe for sucking gas in a container containing molten metal, wherein the sucked gas in the container is discharged to the outside of the container. and a filter part provided at the tip of the tube body inserted into the container and covering the opening of the tip from the outside, wherein the filter part includes the A plurality of filters are stacked to allow passage of gas in the container and prevent passage of molten metal dust. A gas sampling tube is provided having a filter removal mechanism that exposes a filter inward of the filter of the gas sampling tube.

The plurality of filters may be provided inside a cylindrical main body, and the main body may be connected along the axial direction of the main body.

The plurality of filters may be formed in a shape having at least a substantially hemispherical portion.

The filter removing mechanism has a string-like member and a locked portion for locking the string-like member, and the string-like member is cut, or the string-like member and the locked portion are engaged. The outermost filter may be removed by releasing the locking state with the stop portion.

The filter removing mechanism may have a rod-shaped member, and the outermost filter may be dropped by the rod-shaped member coming into contact with the filter section.

The outermost filter may fall off when the pressure loss of the aspirated gas exceeds a threshold.

The plurality of filters may be ceramic filters.

The vessel may be a converter or a converter-type melting furnace.

Further, in order to solve the above problems, according to another aspect of the present invention, there is provided a gas sampling method for sucking gas in a container containing molten metal using a gas sampling pipe, the gas sampling pipe is provided with a hollow pipe body for circulating the sucked gas in the container to the outside of the container, and a plurality of stacked filters that allow the gas in the container to pass and prevent the passage of molten metal dust. and a filter part provided at the tip of the pipe body inserted into the container and covering the opening of the tip from the outside, the step of inserting the gas sampling pipe into the container. and removing the outermost filter of the plurality of filters to expose the filter on the inner side of the outermost filter while sucking the gas. be.

As described above, according to the present invention, there is provided a new and improved gas sampling tube capable of appropriately updating the filter and continuously sampling gas through the gas sampling tube.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the container which concerns on the 1st Embodiment of this invention. It is a front view which shows an example of the gas sampling pipe which concerns on the same embodiment. It is a partial cross-sectional view showing the filter portion of the gas sampling pipe according to the same embodiment. It is a front view which shows an example of the peripheral structure of the filter which concerns on the same embodiment. 4B is an I-I' end view in FIG. 4A. FIG. 4B is a II-II' end view in FIG. 4A. FIG. 4B is a cross-sectional view taken along line III-III' in FIG. 4A; FIG. It is a sectional view showing an example of peripheral structure of a filter concerning the embodiment. It is a perspective view which shows an example of the filter removal mechanism which concerns on the same embodiment. It is a figure which shows the other example of the filter removal mechanism which concerns on the same embodiment. 4 is a flow chart of a gas sampling method according to the embodiment; FIG. 5 is a cross-sectional view showing a filter portion of a gas sampling pipe according to a second embodiment of the present invention; It is a sectional view showing a filter part of a gas sampling pipe concerning a modification of the embodiment.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

<1. First Embodiment>
[Construction of container]
Before describing the gas sampling pipe according to the present embodiment, first, the schematic configuration of a container from which gas is sampled using the gas sampling pipe will be described. FIG. 1 is a cross-sectional view showing an example of a container 1 according to this embodiment. The vessel 1 is, for example, a converter or a converter-type melting furnace. The gas that is blown into the converter or converter-type melting furnace from the gas sampling pipe includes gas containing oxygen.

As shown in FIG. 1, the container 1 is a bottomed cylindrical container with an open top, and contains a molten metal M therein. The vessel 1 may be provided with a blowing pipe 2 for blowing gas toward the surface of the molten metal M. The blowing pipe 2 is inserted into the container 1 through an opening at the top of the container 1 . The tip position of the blowing pipe 2 is set at a predetermined distance from the liquid surface of the molten metal M. As shown in FIG. An example of the gas blown into the container 1 from the blow pipe 2 is a gas containing oxygen.

A gas sampling pipe 10 according to this embodiment is inserted into the container 1 through an opening at the top of the container 1 . The gas sampling pipe 10 is moved up and down so that the tip 13 of the gas sampling pipe 10 is positioned at a position corresponding to the upper portion of the container 1 , and the gas sampling pipe 10 is set at a height position within the container 1 . Further, the gas sampling pipe 10 is arranged at a predetermined distance in the horizontal direction from the blowing pipe 2, as shown in FIG. A gas sampling tube 10 may be attached to the blowing tube 2 .

[Configuration of gas sampling pipe]
Next, the configuration and filter structure of the gas sampling pipe 10 according to the present embodiment will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a front view showing an example of the gas sampling pipe 10 according to this embodiment. FIG. 3 is a partial cross-sectional view showing the filter section 100 of the gas sampling pipe 10 according to this embodiment.

The gas sampling pipe 10 has a function of sampling the gas inside the container 1 . As shown in FIG. 2 , the gas sampling pipe 10 includes a pipe body portion 11 and a filter portion 100 .

The pipe main body 11 is a long hollow steel pipe. An opening 17 is provided at the tip 13 of the tube main body 11 . As shown in FIG. 3, the pipe main body 11 causes the gas in the container 1 sucked from the opening 17 by the suction pump 15 to flow out of the container 1 through the inside of the pipe (see the arrow in FIG. 2). The suction pump 15 is a pump for sucking the gas in the container 1, and various known gas pump devices are used. The pipe body 11 may be equipped with a water-cooled cooling mechanism in order to withstand the high-temperature environment inside the container 1 .

The filter part 100 is provided at the tip 13 of the pipe main body part 11 inserted into the container 1, and has the function of allowing the gas in the container 1 to pass through and preventing the molten metal dust from passing through. As shown in FIG. 3, the filter section 100 is provided so as to cover the opening 17 at the tip of the tube body section 11 from the outside.

The filter section 100 has a plurality of filters 101, a mounting section 110, a body section 120, and a filter removal mechanism (not shown) (corresponding to the filter removal mechanism 130 in FIGS. 5A and 5B described later).

The plurality of filters 101 are made of a material that allows gas within the vessel 1 to pass and prevents molten metal dust from passing. As the filter 101, a known ceramic filter can be used. Further, the filter 101 is provided with holes for allowing gas to flow. The shape of such holes can take various shapes such as a honeycomb shape and a circular shape.

A plurality of filters 101 are provided so as to be stacked from the outer side of the filter section 100 toward the opening 17 . Each filter 101 is provided so that it can be removed in order from the outside by a filter removing mechanism, which will be described later.

The body portion 120 is a cylindrical member forming the outer shape of the filter portion 100 . At least one filter 101 is provided inside one body portion 120 . That is, when the tubular main body 120 is viewed in the axial direction, the filter 101 is arranged so as to close the opening of the main body 120 (so that the axial direction of the main body 120 and the surface on which the filter 101 extends are perpendicular to each other). is provided.

As shown in FIG. 3, the plurality of main body portions 120 are connected along the axial direction of the main body portion 120 . The filter unit 100 includes six filters 101 as shown in FIG. 3, for example. Note that the number of filters 101 is appropriately set according to the amount of suction required for component analysis of the sucked gas and the time required for analysis. As an example, the time required for analysis is about 5 to 10 minutes. In addition, the gas suction speed during analysis is, for example, about 1 L/sec.

The attachment portion 110 is a member for attaching the filter portion 100 to the distal end 13 of the tube body portion 11 . As shown in FIG. 3, the attachment portion 110 is attached to the main body portion 120 provided on the pipe main body portion 11 side among the plurality of main body portions 120 that are continuously provided, and the end portion on the side opposite to the main body portion 120 is attached. A peripheral wall 111 having an inner diameter equal to the outer diameter of the tip 13 of the pipe main body 11 is formed in the inner wall. The filter portion 100 is attached to the pipe body portion 11 by fitting the tip 13 of the pipe body portion 11 into the peripheral wall 111 of the attachment portion 110 . By fitting the tip 13 of the tube main body 11 into the peripheral wall 111 of the mounting portion 110 , the opening 17 of the tip 13 of the tube main body 11 is covered with the filter section 100 from the outside.

The filter removal mechanism removes the outermost filter 101 among the plurality of filters 101 to expose the filter 101 on the inner side of the outermost filter 101 . Details of the filter removal mechanism will be described later. The configuration of the gas sampling pipe 10 has been described above.

[Peripheral structure of filter]
Next, an example of the peripheral structure of the filter 101 according to this embodiment will be described with reference to FIGS. 4A to 4D. FIG. 4A is a front view showing an example of the peripheral structure of the filter 101 according to this embodiment. FIG. 4B is an II' end view in FIG. 4A. FIG. 4C is a II-II' end view in FIG. 4A. FIG. 4D is a cross-sectional view taken along line III-III' in FIG. 4A. Below, as a peripheral structure of the filter 101, the body part 120 provided with the filter 101 will be described.

As shown in FIG. 4A, the body portion 120 has a tip portion 121 protruding from one end in the axial direction. The distal end portion 121 has a truncated cone shape whose diameter decreases in the projecting direction from one end of the main body portion 120 . The tip portion 121 has a hollow interior and communicates with the hollow portion of the main body portion 120 .

As shown in FIGS. 4A and 4C, the hollow portion of the distal end portion 121 is provided with a locked portion 131 and an extending portion 133, which are part of the filter removing mechanism 130, which will be described later. As shown in FIG. 4D , a filter 101 is provided on the truncated cone-shaped end surface of the distal end portion 121 . Note that the installation position of the filter 101 is not limited to the distal end portion 121 and may be any position on the inner peripheral side of the main body portion 120 . For example, the filter 101 may be provided inside the hollow portion of the body portion 120 .

As shown in FIGS. 4A and 4B, an inserted portion 123 having a shape corresponding to the external shape of the tip portion 121 is formed on the inner peripheral surface of the hollow portion on the other axial end side of the body portion 120 . When the body portions 120 are connected, the tip portion 121 protruding from one body portion 120 is fitted into the fitting portion 123 of the other body portion 120 .

By inserting the distal end portion 121 into the inserted portion 123 of another main body portion 120, it becomes easier to position the main body portions 120 when the plurality of main body portions 120 are arranged in a row. In addition, since the main body portions 120 are accurately connected to each other, the gap between the main body portions 120 is eliminated, and it is possible to prevent the main body portion 120 from becoming difficult to come off due to melted dust adhering to the gap. An example of the peripheral structure of the filter 101 according to the present embodiment has been described above.

Next, an example of the filter removal mechanism 130 according to this embodiment will be described with reference to FIGS. 4C, 5A, and 5B. FIG. 5A is a cross-sectional view showing an example of the peripheral structure of the filter 101 according to this embodiment. Also, FIG. 5B is a perspective view showing an example of the filter removal mechanism 130 according to this embodiment.

As shown in FIG. 5A , the filter removal mechanism 130 has a locked portion 131 , an extension portion 133 , a string-like member 135 and a stopper 137 .

As shown in FIG. 5B, the locked portion 131 is a cylindrical member. The locked portion 131 is provided inside the distal end portion 121 at the distal end of the extending portion 133 in the extending direction.

The extending portion 133 is a thin plate member. As shown in FIGS. 4C and 5A, one longitudinal end of the extending portion 133 is attached to the inner peripheral wall surface of the distal end portion 121 . The extending portion 133 is provided extending from the inner peripheral wall toward the axial center of the distal end portion 121 . Further, the outer peripheral surface of the locked portion 131 is attached to the other end of the extending portion 133 in the longitudinal direction.

The string-like member 135 is a carbon fiber string that indirectly or directly holds the filter 101 via the locked portion 131 . One end of the string-like member 135 is locked to the locked portion 131 . On the other hand, the other end of the string-like member 135 reaches the outside of the container 1 along the pipe body 11 .

The string-like member 135 is inserted through the cylinder of the locked portion 131 . The string-like member 135 has a stopper 137 at one end for being locked to the locked portion 131 .

As shown in FIG. 5B, the stopper 137 is a thin plate member having sides longer than the inner diameter of the tube of the locked portion 131 . One end of the string member 135 is attached to the center of one surface of the stopper 137 .

Due to the tension applied to the string member 135 , one surface of the stopper 137 is brought into contact with the axial edge of the cylindrical locked portion 131 . As a result, the string-like member 135 and the locked portion 131 are locked.

Note that the shape of the locked portion 131 is not limited to a cylindrical shape. For example, the locked portion 131 may be a ring-shaped member or a plate-shaped member provided with a slit. Further, the extending portion 133 may not be provided, and the locked portion 131 may be directly attached to the tip portion 121 or the like.

Moreover, the string-like member 135 may have the necessary heat resistance and strength according to the environment inside the container 1, and the material is not limited to carbon fiber. Moreover, the shape of the stopper 137 is not limited to a thin plate shape. For example, the stopper 137 may be a rod, a sphere, a knot provided on the string member 135, or the like.

Next, the operation of removing the filter 101 by the filter removing mechanism 130 will be described. That is, when the string-like member 135 and the engaged portion 131 are in the locked state, the other end side (outside of the container 1) of the string-like member 135 corresponding to each filter 101 is cut. As a result, the tension applied to the string-like member 135 is eliminated, and the filter 101 held at a predetermined position via the engaged portion 131 falls off.

Alternatively, when the string-like member 135 and the locked portion 131 are in the locked state, the string-like member 135 is removed from the stopper 137 by pulling the other end side of the string-like member 135 . As a result, the locked state between the stopper 137 and the locked portion 131 is released, and the filter 101 held at the predetermined position via the locked portion 131 falls off.

As described above, the string-like member 135 is operated and the locked state between the string-like member 135 and the locked portion 131 is released, so that the filter 101 falls off. Therefore, the filter 101 can be removed from the outside of the container 1 . Moreover, the filter removal mechanism 130 is realized by a relatively simple mechanism of combining the string member 135 and the engaged portion 131 .

In this embodiment, the filter removal mechanism 130 is configured to include the string-like member 135 and the locked portion 131, but the present invention is not limited to this example. For example, filter removal mechanism 130 may be a rod-shaped member.

FIG. 6 is a diagram showing another example of the filter removing mechanism 130 according to this embodiment. As shown in FIG. 6 , the rod-shaped member 139 as the filter removal mechanism 130 is a rod with one end extending to the vicinity of the filter section 100 and the other end extending to the outside of the container 1 . Ceramic is an example of the material of the rod-shaped member 139 . When one end of the rod-shaped member 139 contacts the filter section 100, the outermost filter 101 falls off due to the vibration or external force applied at the time of contact. Since the filter 101 is dropped by operating the bar member 139 , the filter 101 can be dropped from the outside of the container 1 . Further, the filter removal mechanism 130 is realized by a simple mechanism such as the rod-shaped member 139 .

[Gas sampling method]
Next, a gas sampling method according to this embodiment will be described with reference to FIG. FIG. 7 is a flow chart of the gas sampling method according to this embodiment. As shown in FIG. 7, first, the gas sampling pipe 10 is inserted into the container 1 (S101). At this time, the tip 13 of the gas sampling pipe 10 is set at a predetermined position. Subsequently, the gas in the container 1 is sucked through the gas sampling pipe 10 (S103). The start of gas suction is appropriately set according to the time when the reaction of the molten metal M in the vessel 1 reaches a steady state. The gas sucked by the gas sampling pipe 10 is subjected to qualitative and quantitative analysis of gas components by known analysis techniques.

In step S103, the gas pressure is measured while the gas is being sucked. Then, it is determined whether or not the pressure loss exceeds the threshold based on the gas pressure measurement result (S105). When the filter is clogged due to adhesion of molten metal dust, the pressure of the sucked gas decreases, resulting in pressure loss. When the pressure loss exceeds the threshold, the filter removal mechanism 130 removes the outermost filter 101 (S107). This exposes the filters on the inner side of the outermost filter. On the other hand, if it is determined in step S105 that the pressure loss has not exceeded the threshold value, the process proceeds to step S109. In addition, in step S105, instead of the pressure loss, it may be determined whether or not the gas flow rate has become equal to or less than the threshold value.

Subsequently, it is determined whether or not the sampling necessary for analyzing the gas components in the container 1 has been completed (S109). If it is determined that sampling is complete, gas sampling ends. On the other hand, if it is determined that the sampling has not been completed, the process returns to step S103 to continue gas suction. The gas sampling method according to the present embodiment has been described above.

The configuration of the gas sampling pipe 10 according to the present embodiment and the gas sampling method using the same have been described above. According to this embodiment, the filter section 100 covers the opening 17 of the tip 13 of the gas sampling pipe 10 from the outside, and the filter removal mechanism renews the plurality of filters 101 of the filter section 100 . As a result, even in an environment where molten metal dust is scattered at a high concentration, the gas sampling pipe 10 sucks gas while renewing the filter 101 by the filter removing mechanism 130, so that gas can be continuously sampled. can. Further, since the filter portion 100 covers the opening 17 from the outside, molten metal dust does not adhere to the gap between the gas sampling pipe 10 and the filter portion 100, and the filter can be appropriately renewed.

Further, according to the present embodiment, since the filter 101 is provided inside the cylindrical body portion 120, it is possible to prevent the filter 101 and the pipe body portion 11 from being welded together by molten metal dust. It becomes easier to update the filter 101 . In addition, as shown in FIG. 3, the main body portion 120 is connected along the axial direction, so that the flow of gas sucked into the filter portion 100 is controlled in one direction, and the molten metal dust is removed from the filter 101. It is possible to suppress welding to places other than.

<2. Second Embodiment>
Next, a second embodiment according to the present invention will be described. This embodiment differs from the first embodiment in the shape of the filter and how the filter is attached to the pipe main body 11 . Specifically, the filter according to this embodiment has a hemispherical filter. The configuration of the tube main body 11, the gas suction method, and the like of this embodiment are the same as those of the first embodiment, so description thereof will be omitted.

A gas sampling pipe 10 according to this embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the filter section 200 of the gas sampling pipe 10 according to this embodiment. The filter section 200 has a plurality of filters 201 to 206, a base section 210, a flange section 220, and a filter removing mechanism (not shown).

As shown in FIG. 8, the filter portion 200 covers the opening 17 at the tip 13 of the tube body portion 11 from the outside. Specifically, the base portion 210 has a cylindrical peripheral wall surface 211 with one end opened, and a bottom surface 213 covering the opening at the other end of the peripheral wall surface 211 . The tip 13 of the pipe main body 11 is inserted into the inner periphery of the peripheral wall surface 211 of the base portion 210 and penetrates through the bottom surface 213 . With the tip 13 penetrating through the bottom surface 213, the flange portion 220 and the edge portion of the peripheral wall surface 211 on the other end side abut and are fixed to each other. The opening 17 of the tip 13 passing through the bottom surface 213 is covered with a plurality of filters 201-206. Note that the base portion 210 may be provided with a water cooling mechanism in the same manner as the pipe body portion 11 .

The plurality of filters 201 to 206 are formed in substantially hemispherical shapes and have similar shapes with radii different from each other. A plurality of filters 201 to 206 are stacked in the filter section 200 . That is, the plurality of filters 201-206 are each housed inside a hemispherical filter having a larger diameter. Also, the opening 17 is accommodated inside the filter 206 having the smallest diameter.

Edges of the plurality of filters 201 to 206 are attached to the outer surface of the bottom surface 213 of the base portion 210 . A plurality of filters 201 to 206 are attached to the bottom surface 213 concentrically around the opening 17 .

As the filter removing mechanism according to this embodiment, the string-like member 135 and the engaged portion 131 as the filter removing mechanism 130 according to the first embodiment as described in FIGS. 5A and 5B can be used. Further, as the filter removing mechanism according to this embodiment, the rod-shaped member 139 as the filter removing mechanism 130 according to the modified example of the first embodiment as shown in FIG. 6 can be used. By the filter removal mechanism according to this embodiment, the edges of the plurality of filters 201 to 206 are removed from the bottom surface 213, the outermost filters fall off, and the inner filters are exposed.

According to this embodiment, since the plurality of filters 201-206 are hemispherical in shape, the surface area of the plurality of filters 201-206 is minimized. Therefore, the possibility of molten metal dust adhering to the plurality of filters 201-206 is reduced. Also, the plurality of filters 201 to 206 are each housed inside a hemispherical filter having a larger diameter. This reduces the space required to provide multiple filters 201-206.

In the present embodiment, an example in which the plurality of filters 201 to 206 are attached via the base portion 210 has been described, but the present embodiment is not limited to this. For example, in the present embodiment, the tip 13 may not be provided with the base portion 210 , the flange portion 220 may be attached to the outer peripheral surface of the tip 13 , and the plurality of filters 201 to 206 may be attached to the flange portion 220 .

[Modification]
Next, a modification of this embodiment will be described with reference to FIG. In this modified example, the shape of the filter portion is different from that of the filter portion of the above-described embodiment. FIG. 9 is a cross-sectional view showing the filter portion 300 of the gas sampling pipe 10 according to this modification. As shown in FIG. 9, the filter part 300 covers the opening 17 at the tip 13 of the tube body part 11 from the outside. The filter section 300 has a plurality of filters 301 to 306, a flange section 320, and a filter removing mechanism (not shown). The plurality of filters 301-306 have hemispherical portions 311-316 and tubular portions 321-326, respectively.

The plurality of filters 301 to 306 are formed by attaching semispherical portions 311 to 316 formed in substantially hemispherical shapes to one end edges of cylindrical cylindrical portions 321 to 326, respectively. The filters 301 to 306 have similar shapes with different sizes.

A plurality of filters 301 to 306 are stacked in the filter section 200 . That is, the plurality of filters 301-306 are each housed inside a hemispherical portion and a tubular portion of a larger filter. Also, the opening 17 is accommodated inside the smallest filter 306 .

The other end edges of the tubular portions 321 to 326 of the filters 301 to 306 are attached to the flange portion 320 . A plurality of filters 301 to 306 are attached to the flange portion 320 concentrically around the opening 17 .

A filter removing mechanism (not shown) removes the edges of the tubular portions 321 to 326 of the plurality of filters 301 to 306 from the flange portion 320, dropping the outermost filters and exposing the inner filters.

According to this modification, the plurality of filters 301-306 have cylindrical portions 321-326, so the surface areas of the plurality of filters 301-306 are increased. As a result, the number of gas flow holes provided in the plurality of filters 301 to 306 is increased, and the time until the plurality of filters 301 to 306 are clogged by adhering molten metal dust can be lengthened.

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

1 Container 2 Blowing Pipe 10 Gas Sampling Pipe 11 Pipe Main Body 13 Tip 15 Suction Pump 17 Opening 100, 200, 300 Filter Part 101, 201 to 206, 301 to 306 Filter 120 Main Body 130 Filter Removal Mechanism 131 Engaged Part 133 extending portion 135 string-like member 137 stopper 139 rod-like member 311 to 316 hemispherical portion M molten metal

Claims (9)

A gas sampling pipe for sucking gas in a container containing molten metal,
a hollow pipe body for circulating the sucked gas in the container to the outside of the container;
a filter part provided at the tip of the pipe main body inserted into the container and covering the opening of the tip from the outside;
has
In the filter section,
A plurality of filters are stacked to allow passage of gas in the container and prevent passage of molten metal dust,
A gas sampling pipe provided with a filter removing mechanism that removes an outermost filter among the plurality of filters to expose a filter on the inner side of the outermost filter. The plurality of filters are provided inside a cylindrical main body,
2. The gas sampling pipe according to claim 1, wherein the body portion is continuous along the axial direction of the body portion. 3. The gas sampling tube according to claim 1, wherein said plurality of filters are formed in a shape having at least a substantially hemispherical portion. The filter removal mechanism is
a string-like member;
a locked portion for locking the string-like member;
4. The filter according to claim 1, wherein the outermost filter is dropped by cutting the string-like member or releasing the locked state between the string-like member and the locked portion. or the gas sampling tube according to claim 1. The filter removal mechanism has a rod-shaped member,
The gas sampling pipe according to any one of claims 1 to 4, wherein the outermost filter is removed by contact of the rod-like member with the filter portion. Gas sampling tube according to any one of claims 1 to 5, wherein the outermost filter is dropped when the pressure loss of the aspirated gas exceeds a threshold. The gas sampling tube of any one of claims 1-6, wherein the plurality of filters are ceramic filters. The gas sampling tube according to any one of claims 1 to 7, wherein the vessel is a converter or converter-type melting furnace. A gas sampling method for sucking gas in a container containing molten metal using a gas sampling pipe,
The gas sampling tube is
a hollow pipe body for circulating the sucked gas in the container to the outside of the container;
A plurality of filters are provided in a layered manner for allowing the gas in the container to pass through and preventing the molten metal dust from passing through. a filter portion covering the opening from the outside;
and
inserting the gas sampling tube into the container;
a step of removing the outermost filter of the plurality of filters and sucking the gas while exposing the filter on the inner side of the outermost filter;
A gas sampling method, comprising:

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