GB1602702A

GB1602702A - Apparatus for sampling molten metal

Info

Publication number: GB1602702A
Application number: GB15906/78A
Authority: GB
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1977-04-21
Filing date: 1978-04-21
Publication date: 1981-11-18
Also published as: FR2388266A1; IT7822599A0; JPS5858029B2; IT1094454B; JPS5439188A; FR2388266B1

Description

(54) APPARATUS FOR SAMPLING MOLTEN METAL (71) We, MANNESMANN AKTIENGESELL SCHAFT, a joint stock company organised under the laws of Germany, of 4 Dusseldorf 1, Mannesmannufer 2, Germany, and GUSTAV KOLB, of 5984 Garbeck. Germany, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to an apparatus for taking samples of molten metal.

It is known to take samples from metal baths for analysis purposes. To this end, use is made of apparatus comprising two half shells of refractory ceramic material provided with recesses for receiving the sample material. The half shells are held together by a tube. Preferably, this tube is made of cardboard and serves as a handle for the apparatus. i.e. for immersing the apparatus in the metal bath and removing the sample from the bath. Apparatus of this kind is described in German Patent Publications No. 25 19957. With apparatus of this kind, it customary to obtain samples in the shape of pins and discs. In the sampling of molten steel. particularly from a converter. the unkilled steel must be killed inside the sampling apparatus by means of a deoxidising agent. preferably aluminium.In addition, it is necessary for the deoxidising agent to be distributed extremely uniformly in the sample obtained in order to avoid faulty results during subsequent spectral analysis.

Known sampling apparatus are inadequate for the present high quality requirements.

We have sought to improve the chemical uniformity of the samples obtained.

Accordingly. the present invention provides a sampling apparatus for molten metal which comprises a two-part refractory ceramic body which, on the outside, is provided with a stop adapted to support a carrier tube and which is provided in a mirror image arrangement in each part of the body with recesses for a disc-shaped sample body and a pin-shaped sample body. and in which a duct inlet disposed in one face of the body discharges into a mixing chamber having an inlet duct leading into the recess for the pin-shaped sample body. the apertures for the inlet duct and the outlet duct lie side by side in one half of the mixing chamber.

Through the arrangement and configuration of the mixing chamber of the present invention, complete dissolution of the deoxidising agent and its uniform distribution within the disc-shaped or pin-shaped sample is achieved even during the short period of filling of the sampling apparatus when immersed in a steel bath.

The present invention is further illustrated in the accompanying drawings, wherein: Figure 1 shows a longitudinal section through the sampling apparatus in the plane of the dividing surface between the two half shells or body part; and Figure 2 shows longitudinal section through a modified embodiment of the present invention.

The apparatus shown in Figure consists of a refractory ceramic body 1 in the form of a half cylinder. The body 1 can be inserted into a cardboard tube 3 as far as stop 2 extending around it on the outside. An inlet duct 6 leads from end 7 of the body 1. The end 7 is protected by a metal cape (not shown) which is knownperse and which can be placed over that part of the body 1 projecting from the cardboard tube. It is so constructed that it melts only after penetration of slag floating on the metal bath thus freeing the inlet duct 6 for the admission of metal. The inlet duct 6 is disposed eccentrically and obliquely in relation to the longitudinal axis of the body 1 and leads into mixing chamber 9. The inlet duct 6 has a widened portion 13 adapted to hold a deoxidising agent. The mixing chamber 9 may have the shape of a disc or a sphere.

The mixing chamber 9 is in communication by way of an outlet duct 10 with succeeding recesses 5 for a pin-shaped sample and 4 for a disc-shaped sample.

The apertures for the inlet duct 6 and outlet duct 10 lie side by side in one half of the mixing chamber 9 and are separated from one another by a shoulder 11 extending into the mixing chamber 9. A flow obstacle 12 in the form of a projection is also disposed inside the mixing chamber 9. The cavity for the disc-shaped sample 4 is provided with a venting hole 14 which is in communication with the interior of the tube 3.

In the embodiment shown of Figure 2, all corresponding parts are in each case indicated by the same numerals as in Figure 1 until the addition of a prime.

The mixing chamber 9' is of a cylindrical shape and is in communication by way of the outlet duct 10' with the succeeding recesses 5' for a pinshaped sample and 4' for a disc-shaped sample.

The apparatus is preferably so shaped that the volume of the mixing chamber 9' is at least 1.5 times and more preferably from 2 to 3 times as large as that of the disc sample cavity 4' . Further, the mixing chamber 9' is provided with a venting hole 15 at a point remote from where the sample is taken. Further. the outlet duct 10' has a smaller cross-section than the pin-shaped sample chamber 5'. According to an advantageous development of the invention. the reduction of the cross-section is formed by a wedge-shaped projection 16 extending around the duct to form an orifice with an internal diameter of from 2 to 4 mm. Further, it has been found advantageous for the deoxidising agent to be used in the form of a spirally wound wire. the latter expediently being disposed in the inlet duct 6'.For that purpose the duct is provided with a lateral hole 19 into which a bent end of the spirally wound wire is inserted for fastening purposes.

The embodiment of the apparatus of the present invention shown in Figure 2 provides the advantage that because of the venting hole and the narrowing of the outlet cross-section. the mixing chamber is first filled with the inflowing metal and is completely killed. the killing agent being uniformly distributed in the molten metal.

It is thus ensured that the actual sampling chambers 4' and 5' will be filled with a uniform sample. Further. the constriction of the inlet duct 10' provides the advantage that when the sampling body is broken up. the actual sample bodies 4' and 5' are obtained separately from the remainder of the sample in the mixing chamber 9'. The constriction thus at the same time serves as a pre-determined braking point and simplifies the preparation of the samples.

WHAT WE CLAIM IS: 1. A sampling apparatus for molten metal which comprises a two-part refractory ceramic body which, on the outside, is provided with a stop adapted to support a carrier tube and which is provided in a mirror image arrangement in each part of the body with recesses for a disc shaped sample body and a pin-shaped sample body. and in which a duct inlet disposed in one face of the body discharges into a mixing chamber having an outlet duct leading into the recess for the pin-shaped sample body, the apertures for the inlet duct and the outlet duct lie side by side in one half of the mixing chamber.

2. An apparatus as claimed in Claim 1, wherein the inlet duct and the outlet duct are separated by a projection extending into the mixing chamber.

3. An apparatus as claimed in claim 1 or2, wherein the boundary surface of the mixing chamber is provided with at least one flow obstacle projecting into the mixing chamber.

4. An apparatus as claimed in any of claims I to 3, wherein the mixing chamber has a circular cross-section.

5. An apparatus as claimed in any of claims 1 to 4, wherein the inlet duct leads tangentially into the mixing chamber.

6. An apparatus as claimed in any of claims 1 to 5, wherein the inlet duct has in cross-section a widened portion adapted to hold a de-oxidising agent.

7. An apparatus as claimed in any of claims 1 to 6. wherein the disc-shaped sample body is provided with a vent hole.

8. An apparatus as claimed in any of claims 1 to 7, wherein the inlet duct is inclined in relation to the longitudinal axis of the ceramic body.

9. An apparatus as claimed in Claim 1, wherein the volume of the mixing chamber is at least 1.5 times as large as that of the disc-shaped sample body, the mixing chamber is provided with a venting hole and the outlet channel has a smaller cross-section than the pin-shaped sample body.

10. An apparatus as claimed in Claim 9, wherein the smaller cross-section is formed by a wedge-shaped projection which forms an orifice.

II. An apparatus as claimed in claim 9 or 10.

wherein the mixing chamber has a volume from 2 to 3 times as large as that of the disc-shaped sample body.

12. An apparatus as claimed in any of claims 9 to 11. wherein the inlet duct has a lateral hole for fastening a spirally-shaped deoxidising agent.

13. A sampling apparatus for molten metal substantially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. In the embodiment shown of Figure 2, all corresponding parts are in each case indicated by the same numerals as in Figure 1 until the addition of a prime. The mixing chamber 9' is of a cylindrical shape and is in communication by way of the outlet duct 10' with the succeeding recesses 5' for a pinshaped sample and 4' for a disc-shaped sample. The apparatus is preferably so shaped that the volume of the mixing chamber 9' is at least 1.5 times and more preferably from 2 to 3 times as large as that of the disc sample cavity 4' . Further, the mixing chamber 9' is provided with a venting hole 15 at a point remote from where the sample is taken. Further. the outlet duct 10' has a smaller cross-section than the pin-shaped sample chamber 5'. According to an advantageous development of the invention. the reduction of the cross-section is formed by a wedge-shaped projection 16 extending around the duct to form an orifice with an internal diameter of from 2 to 4 mm. Further, it has been found advantageous for the deoxidising agent to be used in the form of a spirally wound wire. the latter expediently being disposed in the inlet duct 6'.For that purpose the duct is provided with a lateral hole 19 into which a bent end of the spirally wound wire is inserted for fastening purposes. The embodiment of the apparatus of the present invention shown in Figure 2 provides the advantage that because of the venting hole and the narrowing of the outlet cross-section. the mixing chamber is first filled with the inflowing metal and is completely killed. the killing agent being uniformly distributed in the molten metal. It is thus ensured that the actual sampling chambers 4' and 5' will be filled with a uniform sample. Further. the constriction of the inlet duct 10' provides the advantage that when the sampling body is broken up. the actual sample bodies 4' and 5' are obtained separately from the remainder of the sample in the mixing chamber 9'. The constriction thus at the same time serves as a pre-determined braking point and simplifies the preparation of the samples. WHAT WE CLAIM IS:

1. A sampling apparatus for molten metal which comprises a two-part refractory ceramic body which, on the outside, is provided with a stop adapted to support a carrier tube and which is provided in a mirror image arrangement in each part of the body with recesses for a disc shaped sample body and a pin-shaped sample body. and in which a duct inlet disposed in one face of the body discharges into a mixing chamber having an outlet duct leading into the recess for the pin-shaped sample body, the apertures for the inlet duct and the outlet duct lie side by side in one half of the mixing chamber.

II. An apparatus as claimed in claim 9 or 10.