JPH0350158B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the construction of conduit connections for high-temperature fluids that exhibit a relatively high freezing point, particularly in the process of producing refractory metals such as Ti and Zr by reduction of their chlorides. This invention relates to a conduit connection configuration of a device used to separate mixed Mg and MgCl ₂ .

Refractory metals such as Tu and Zr are widely produced by reducing their chlorides with molten magnesium. In this case, Ti and Zr usually precipitate in the form of a sponge and are obtained as a mixture with the by-product MgCl ₂ and the residual metal Mg. The mixture is heated, for example, to vaporize the Mg and MgCl ₂ and remove them from the solid precipitated metal (possibly partially as a liquid) to recover the purified metal.

Various configurations have been proposed to perform such steps, and some of them have been implemented. The present inventor previously proposed such a device configuration in Japanese Patent Application Laid-Open No. 58-210128. This device essentially
A reduction and evaporation chamber for reducing the metal chloride to be produced with molten Mg and vaporizing and separating Mg and MgCl ₂ from the precipitated metal by heating, and a chamber for cooling and condensing the thus vaporized Mg and MgCl ₂ . It consists of a condensing chamber, both of which are juxtaposed and connected by a connecting pipe provided with heating means. In some examples, the condensation chamber is configured using a cylinder that is common to the reduction evaporation chamber (or the inner cylinder in the case of an inner/outer cylinder configuration), which deposits Mg or MgCl ₂ on the wall surface and connects the two chambers. After being solved, it is placed in a reduction and evaporation chamber for the next reaction.

The connecting tube is separably joined at the top of both chambers, or in some cases at the middle of the connecting tube. Fusing and welding methods can be used as such joining methods, especially in the middle part, but they are not only complicated or difficult to operate, but also have a limit to repeated use, and mechanical joining methods are not suitable. is desirable.

Mechanical connection of conduits for fluids with high solidification temperatures has conventionally been accomplished using flanges provided at each connection end of the pipe body and packing made of heat-resistant material such as heat-resistant rubber sandwiched between both flanges. It was hot. However, in the connecting tube of the device related to the above-mentioned patent application and similar conduits, the tube wall must be kept at a sufficiently high temperature in order to maintain the fluidity of Mg, _MgCl2, etc. flowing inside the tube. On the other hand, when a flange-packing configuration is used, in order to ensure the sealing function of the packing for a long period of time, the flange must be kept in a temperature range that does not deteriorate the packing material by water cooling or the like. To do this, it is necessary to make the diameter of the flange extremely larger than that of the tube body and to arrange packing around the outer periphery. This places great restrictions on the location of the pipes and is extremely disadvantageous, or even impossible, when carrying out such construction in small confined areas. As is easily understood, reducing the flange diameter
The wall temperature decreases near the pipe connection, that is, the flange to be cooled, and Mg and MgCl ₂
becomes easier to precipitate. Once Mg is precipitated, it has high thermal conductivity and is easily cooled, so it continues to precipitate on top of Mg, which tends to cause clogging. Therefore, in order to arrange such a conduit or connecting pipe in a limited space, it is desired to develop a small-diameter joint that solves the contradictory problems of ensuring a high temperature for the pipe wall and a low temperature for the packing.

The present invention has been made to solve these problems, and its gist is that in a pipe body for high-temperature fluid transfer consisting of two parts to be connected facing each other, each of these pipes is At least the opposing ends of the body part have a double-wall structure consisting of an inner and outer wall, and the heating medium is disposed inside the space between the walls, and a flange-type coupling is provided on the outer wall at a position spaced apart from the end of the tube part. A connection configuration for a hot fluid conduit is provided.

That is, in the present invention, when connecting a pair of tube portions facing each other by a flange type coupling means using packing and having a means for cooling the packing material, in particular, the opposite ends of both tube portions are connected. The part including the double-walled structure is provided with a heating means in the space between the two walls. The base of at least one flange of the coupling means is located on the outer wall of the double-walled structure at a location spaced from the end. A packing made of heat-resistant rubber is typically inserted and arranged between the flanges of both tube parts. Packing material is a means of cooling (typically water cooling)
The sealing function is ensured by forced cooling to near room temperature. On the other hand, a heating means as described below is provided between this cooling means and the conduit through which the high-temperature fluid passes, and it is possible to maintain a sufficiently high temperature even near the end of the pipe body where the coupling is provided. Therefore, the distance between the cooling means and the outer wall of the conduit, and ultimately the radius of the coupling (flange), can be designed to be small, and in this respect, the conduit can be made smaller.

The pipe portions to be connected are heated substantially up to the connecting ends by combustion of oil or gas or by electric heating. For example, the tube wall may be doubled to provide a gas path independent from the inside of the tube, and a gas burner, for example, may be inserted into this path for combustion, and the high temperature gas obtained at this time may be circulated. If electric heating is used, the heater element is buried in this area and covered with a layer of insulating material. These connecting ends are arranged with some gap in view of expansion during heating, but it is preferable to make this gap as small as possible so long as the two ends do not come into contact at the operating temperature.

Next, the present invention will be explained in detail with reference to the accompanying drawings. Fig. 1 is a sectional view of a connection part using a conventional flange joint, Figs. 2 to 4 are sectional views showing a connection part according to the present invention, and Fig. 5 is an example in which the structure of the present invention is applied to the device of the above patent application. (Two-pack configuration inside and outside) is shown.
In particular, in FIG. 1, in the conventional configuration, flanges 3 and 4 are formed at the ends of both tube parts 1 and 2 to be connected, and packings 5 and 6 made of a heat-resistant material such as heat-resistant rubber are used, for example. Both parts are joined by several bolts 7 and 8 via two bolts. A cap nut (not shown) with a water cooling jacket may be fitted onto the head of the bolt. A water cooling jacket 9,1 is attached to the back of one or both of the packings.
0 is set. An outer wall 12 extends approximately coaxially with the inner tube wall 11 to the front of the flanges 3, 4, through which air and combustion gases heated by a gas burner (not shown) are passed. Regarding the size ratio between the pipe and the flange, for example, in the case of an 8B pipe (216 mm), a flange with an outer diameter of about 560 mm is used.

In FIG. 2 showing an embodiment of the present invention, the pipe portions 21 and 22 that are connected are formed into a double-walled structure so that the high-temperature gas flows substantially up to the connecting end. configured to reach. Flanges 23 and 24 are placed on the outer wall slightly inward from the connecting end.
will be provided. Both flanges 23 and 24 are each made of, for example, two heat-resistant rubber packings 25 _1-2 ,
26 _1-2 and is airtightly connected to the spool-type joint 27 having approximately the same diameter as the flange portion, and both flanges and the joint are fixed by several bolts 28 _1-2 and 29 _1-2 . The flanges are provided with water cooling jackets 30, 31 on the back side of one or both packings. In this example, the flange outer diameter is:
It can be made around 445mm.

If the joint does not require that much strength, a configuration in which the above-mentioned joint tool 27 is omitted can be used. 3 and 4 are similar to the configuration shown in FIG. 2 in that each tube portion is provided with heating means that substantially reaches the connecting end. However, in the case of FIG. 3, annular cylindrical parts 33 and 34 coaxial with the pipe body extend outward from near the connecting end, and the outer ends thereof are flange 35,
36, and these are connected to bolts 39 and 4 through heat-resistant packings 37 and 38 as in the case of FIG.
Fixed at 0. In Fig. 4, one flange 41
protrudes beyond the outer end of the tube portion 42, and the other flange 43 is attached at a recessed position somewhat apart from the outer end of the tube portion 44, and is secured with bolts 45, 46 in the same manner as in each of the above examples. be done. In the configurations shown in FIGS. 3 and 4, the mounting position of the flange itself on the outer wall of both tube parts or the small disc-shaped mounting member perpendicular to the axis is such that the connecting end is allowed to extend inside the flange itself. Leave enough space between. As shown in FIG. 5, each of these configurations is applied to a connecting pipe P connecting a reduction evaporation chamber R and a condensation chamber C in a metal chloride reduction and purification apparatus as shown in the above-mentioned patent application, for example. An example of an operation in which Mg reduction of TiCl ₄ was performed using this configuration is shown below.

Example Reduction evaporation chamber outer cylinder 51 made of SUS316 stainless steel
is cylindrical with an inner diameter of 1.7 m, a length of 4.5 m, and a wall thickness of 32 mm.
Inside is SUS430 with an inner diameter of 1.6m, length of 3.7m, and wall thickness of 19mm.
An inner cylinder 52 made of stainless steel was supported via a lid 53, and the entire furnace was placed in an electric furnace 54 with an outer diameter of 2.5 m and a height of 5 m, the circumference of which was covered with an iron shell. The space inside the furnace, that is, the space between the outer cylinder and the furnace, is configured to be airtight. On the other hand, the condensing chamber outer cylinder 55 has the same structure as the outer cylinder of the reduction evaporation chamber, and a lid body 56 similar to that described above is installed therein.
An empty inner cylinder 57 of the same configuration was suspended while being supported by the cylinder. The connecting pipe P connecting the tops of both chambers has an inner diameter of 240 mm.
The total length is approximately 70cm, and the connection section is essentially constructed as shown in Figure 2.A high-temperature gas passage with a height of 30mm (inside) is provided around the outer periphery of the tube section, and several gas burners are used to connect each connection end. was heated. The outer diameter is 720 mm with a distance of 100 mm inward from each connection end.
flanges 58 and 59 were provided, and both flanges were bolted together using a spool-type joint 60 having the same outer diameter as the flanges. The flange was secured with bolts through heat-resistant rubber packing, and a water-cooled jacket was installed to cool the packing.

In this device, the reduction and evaporation chamber was set in an argon atmosphere, and about 7 tons of molten Mg was introduced from the tube 61, and after the inner cylinder was heated to about 800°C, 400 kg of liquid TiCl ₄ was introduced.
The reaction operation was carried out by supplying from tube 62 at a rate of 100 hrs. The by-produced MgCl ₂ was intermittently discharged from the bottom of the outer cylinder through the pipe 63 for about 50 hours in total for a total of 20 hours.
The injection of TiCl ₄ was stopped. Bottom plate 6
Drain all Mg and MgCl ₂ remaining below 4,
The bolts suspending the inner cylinder 52 were turned to lower the inner cylinder a little to form a gap between it and the lower surface of the lid. After evacuating the condensing chamber and heating the lid and connecting pipe of the reduction evaporation chamber R to approximately 800° C., the valve was opened to connect the condensing chamber C immersed in the water tank 65. Heat the reduction evaporation chamber to about 950-1000℃ and Mg
and MgCl ₂ were evaporated and introduced into a condensation chamber, where they were condensed and deposited on the inner cylinder wall surface. At this time, in the reduction evaporation chamber, by operating the surrounding furnace and feeding the gas burner combustion gas into the high temperature gas passage of the lid and the connecting pipe, the temperature of the entire chamber and the entire connecting pipe is raised to approximately 800℃, and at the same time The surrounding furnace space was evacuated.
The purification operation was continued in this manner until the degree of vacuum in the reduction and evaporation chamber reached 10 ^-3 Torr, approximately 70 hours after the final connection of the two chambers. During this period, no problems such as clogging due to deposits occurred in the connecting pipe. After cooling, the connecting bolts were removed, the lid of the reduction and evaporation chamber was removed, and the inner cylinder was then taken out. In the end, 5 tons of Ti sponge were recovered from this inner cylinder. Although Mg and MgCl ₂ were attached to the inner cylinder of the condensation chamber, this was placed in the heating furnace without being taken out from the outer cylinder and used for the next reduction step. On the other hand, the inner cylinder from which the produced Ti was removed was again fitted with a lid and used as the inner cylinder of the condensation chamber.

The above explanation is particularly related to the applicant's earlier application.
Although only an example of application to the device described in Japanese Patent No. 58-210128 has been shown in detail, it is clear that the structure of the present invention can also be applied to conduits for passing high temperature fluids having a similar high freezing point.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing a typical configuration used for conventional high-temperature fluid conduit connections, FIGS. 2-4 are schematic cross-sectional views showing some examples of the configuration according to the present invention, and FIG. 1 is a cross-sectional view showing an example of a device to which the configuration of the invention can be applied. In these figures, each reference symbol represents the following member. 1, 2... pipe body part; 3, 4... flange;
5,6...Packing;7,8...Bolt;9,
10... Water cooling jacket; 11, 12... Pipe wall;
21, 22... Pipe body part; 23, 24... Flange; 25, 26... Packing; 27... Joint;
28, 29... Bolt; 30, 31... Water cooling jacket; 33, 34... Annular part; 35, 36...
Flange; 37, 38... Packing; 39, 4
0... Bolt; 41, 43... Flange; 42,
44...tube part; 45, 46...bolt; R...
...reduction evaporation chamber; C... condensation chamber; P... connection pipe;
(Omitted below).

Claims (1)

[Scope of Claims] 1. A pipe body for high temperature fluid transfer consisting of two parts facing each other and connected to each other, in which at least the opposing ends of each pipe part have a double wall structure consisting of an inner and an outer wall. A connection arrangement for a hot fluid conduit, characterized in that a heating medium is disposed inside the interwall space tube, and a flange-type coupling is provided on the outer wall of the interwall tube at a position spaced apart from the end of the tube section. 2. The conduit connection configuration according to claim 1, wherein the flanges of both tube body portions are connected by bolts via a spool-type joint. 3 A coaxial cylindrical body is provided on the outside of at least one of the tubular body parts, and the inner end of this cylindrical body is fixed to the outer wall via a disc-shaped member perpendicular to the axis of the cylindrical body. The conduit connection arrangement according to claim 1, wherein a flange is provided near the outer end of the cylindrical body. 4. The conduit connection configuration according to claim 1, wherein the heating medium is a high temperature gas containing combustion gas generated by combustion of gas. 5. The conduit connection structure according to claim 1, wherein the heating medium is a heating wire. 6 the opposing ends are spaced apart from each other;
2. A conduit connection arrangement as claimed in claim 1, which is also intended to prevent the end portions from coming into contact with the connecting means due to differences in thermal expansion.