DE2544289A1 - PIPE AND METHOD FOR ITS MANUFACTURING - Google Patents

Description

Patent attorneys: TlEDTKE - BüHLING "Klf4NE

Dip! - lng. Chins

• 5 C / / OQ Ω ⁸ Munich 2, PO Box 202403

Z 0 4 HL P ei Bavariaring 4

Tel .: (0 89) 53 96 53-56

Telex: 5 24845 tipat

cable: Germaniapatent Munich

October 3, 1974 B 6880

.1) MITSUI MINING & SMELTING CO., LTD. '.

Tokyo, Japan

2) -MITSUI KINZOKU ENGINEERING SERVICE CO., LTD -. Tokyo / Japan

Pipe and process for its manufacture

The invention relates to a pipe that is particularly is suitable for the discharge or forwarding of wastewater, as well as a method for the production of such a pipe. The term "pipe" here and in particular in the claims is intended to mean any possible shape of a pipe, a Pipe fitting and a pipe connection piece, for example a straight pipe section, a pipe elbow, a pipe elbow, etc., be understood.

Due to the recently significantly increasing generation of waste in the form of sewage, sludge,

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Deutsche Bank (Munich) Account 51/61070 Dresdner Bank (MOnchen) Account 3939844 Postscheck (Munich) Account 670-43-804

254A289

medical waste fluids, etc., water pollution is increasingly regarded as a serious public problem. To solve this problem, the waste should be through a Pipeline system to be conveyed to a treatment plant, in which a suitable treatment is carried out .. If the sewage is earth and sand ,. Solids or chemicals such as contains an alkali solution, etc., it is necessary that a corresponding pipe has high resistance to wear, Has pressure and corrosion to withstand these aggressive conditions. . '

Most conventional pipes and fittings are made of metal so that they are at least resistant to wear and corrosion do not adequately meet the requirements, and have the disadvantage that they considerably reduce the service life of the pipes or pipe fittings.

To address this difficulty, efforts have been made with the aim of producing a pipe or to provide a pipe connector with a lining made of rubber, synthetic resin and the like. This lining process however, it is tedious and time consuming. However, even such pipe-like objects are not sufficient Resistance to wear, pressure and corrosion among the

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shown heavy loads to which they are exposed. Another solution to the problem mentioned is to to manufacture the tubular objects from ceramic material; however, difficulties arise when such items are machined to the desired accuracy. They also have poor strength in the event of impact and bending stress, so that there is a risk that the pipe or the pipe connection piece will crack or breaks.

The invention has for its object to provide a pipe or pipe connector, for example a. straight To create a piece of pipe, a pipe elbow or a pipe elbow, that has excellent wear, pressure and corrosion resistance and is subject to external impact and bending stress is less prone to cracking and breaking. Furthermore, a method for producing such. Rohres are created. .

Another object of the invention is Creation of a pipe, for example a straight pipe section, a pipe elbow or a pipe elbow, the can be easily machined to the desired accuracy. Furthermore, a method for Manufacture of such a pipe can be created.

A method according to the invention and a pipe according to the invention are characterized in the claims.

A pipe according to the invention is distinguished

made of a hollow, cylindrical core element made of a ceramic material and an outer sheath that defines the tightly enclosing hollow, cylindrical core element and made of an easily machinable material with ' high mechanical strength. As already was mentioned, here under "pipe", for example, a straight pipe section or a pipe connection piece such as, for example a pipe elbow or a pipe elbow can be understood. The outer sheath is preferably made of thermoplastic synthetic resin. If necessary, can Preferably, a flange can be formed in one piece at each end of the outer casing. Furthermore, the outer Sheathing consists of two sheathing halves made of metal, the inside of which has a semicircular cross-section has and is shaped complementary to the outside of the core element, so that these sheath halves by welding or with the help of nuts and bolts can be connected to each other on the core element. The inventive method for producing a pipe provides that ceramic material is shaped in the tough state into a hollow, cylindrical core that the

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cylindrical core is sintered and that tightly fitting an outer jacket on the cylindrical core made of a thermoplastic synthetic resin, which is resistant to external impact and bending loads is. The application of the sheath includes that the outer sheath, the inner diameter of something is larger than the outer diameter of the core element, is heated to such a temperature that it is up to The outer diameter of the core element expands and changes to a soft state, after which the core element with the outer Sheath is coated, which is then cooled so that it lies against the core element and compresses it and makes close contact with the core element. The result is an outer sheathing that is resistant to external impact and bending stress, as a result of which Cracking and breakage of the core element can be prevented.

Embodiments of the invention are shown in the drawings and are shown below explained in more detail. Show it:

1 shows a longitudinal section through a knee according to the invention or an elbow according to the invention;

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FIG. 2 shows a perspective view of a core element of the knee according to FIG. 1;

3 shows the knee according to FIG. 1 in longitudinal section. . disassembled state; ·

4 shows the process step of heating a tubular, outer sheath made of thermoplastic. Synthetic resin to soften them, and the step of cutting the sheath suitable length;

5 shows a longitudinal section through a pipe elbow according to a further embodiment of the invention;

6 shows a cross section according to 6-6 in FIG. 5;

Fig. 7 is a perspective view of the elbow according to Fig. 5 in the disassembled state;

8 shows a longitudinal section through a further embodiment of an elbow according to the invention;

9 shows a cross section according to 9-9 in FIG. 8;

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^ -7—

Pig. 10 a longitudinal section through a further

implementation of the invention in the form of a - Straight pipe section according to 10-10 in Fig. 1;

11 shows a cross section according to 11-11 in Fig. 10; .

Fig. 12. a longitudinal section through another Embodiment of the invention in the form of a straight piece of pipe according to FIGS. 12-12 in Fig. 13;

13 shows a cross section according to 13-13 in FIG. 12;

14 shows a longitudinal section through a further embodiment of the invention in the form a straight pipe section according to 14-14 in FIG. 15; and

15 shows a cross section according to 15-15 in FIG. 14.

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The same reference symbols are used in all drawings to denote the same or identical parts or elements used.

In Fig. 2, a pipe elbow or pipe bend .22 is shown, i.e. an element which is here under the all-. common term "pipe" falls. In the following, the element 22 is predominantly referred to as the knee. This knee includes a hollow cylindrical core member 24 with certain radius of curvature is so curved that its one end face at a right 'angle or another a certain angle to the other end face. Furthermore, the knee 22 comprises an outer sheathing or sheathing .26, which is attached evenly over the entire length of the core element 24, as well as two end flanges 28, of which one at each end portion of the core element 24 is attached or molded. Each of the flanges 28 has Holes 30 through which fastening means (not shown), for example screws, are inserted. As As the perspective view of FIG. 2 most clearly shows, the core element 24 is formed by molding a ceramic Material generated in the tough state. The ceramic material can, for example, be silicon carbide refractory material with a binder such as silicon nitride or silicate. The shaping in the tough

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Sintering follows. A thermoplastic synthetic resin, for example Polyvinyl chloride, polyethylene, or another reinforced plastic material that has a larger size is used has thermal expansion coefficient than metal.

For example, polyvinyl chloride has a thermal effect

—5 ο expansion coefficients of approximately 7.1 χ 10 / C. This Value is significantly higher than that of common metals.

. The outer sheath 26 is designed so that it has an inner diameter that is smaller than that The outer diameter of the core element 24 is. For a knee 22 with a nominal diameter of 2 "(50.8 mm), for example the outer sheath 26 is sized so that it has an inner diameter that is 5 to 6 mm smaller than is the outer diameter of the core element 24. As can be seen most clearly in Fig. 4, the is so dimensioned outer casing 26 of two rollers 32 fed into a heater 34. The temperature in the heater, 34 is set depending on the material, the thickness and the insertion speed of the sheath so that that the outer jacket 26 can be sufficiently softened before it emerges from the heater 34. The outer sheath 26- is softened in the heater as it expands at the same time, and

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then led out of the heating device 34 and from a cutting device or a knife 36 cut to a certain length. Alternatively, the outer Sheath 26 can be cut to a specific length before being allowed to soften in the heating device is heated.

The outer sheath 26 softened in this way can easily both in the longitudinal direction and in the radial direction stretched and brought into the desired shape y / earth, with the result that they are very easy to attach to the core element 24 can be applied. After the outer Cladding 26 has been applied to core element 24, it is cooled, causing it to separate contracts and hardens again and in this way in close contact with the outside of the core element 24 occurs. Therefore, the outer sheath 26 can then no longer easily be pulled off the core element 24.

Then the two flanges 28 at the respective end section of the outer Sheath 26 attached, whereby the knee 22 shown in Fig. 1 is completed. When the flanges 28 consist of the same material as the outer sheath 26, it is very easy to thermally apply this enc.veder

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or to be connected to the outer casing 26 by means of a binding agent. It is also possible to use the flanges 28 to be molded in one piece on the outer casing 26, while this is being formed.

A knee shown in FIGS. 5 to 7 comprises a core element 24 made of the same material and with the same structure as the core element 24 according to FIGS. 1 to 3, the manufacturing method also being the same and an outer jacket 126 made of metal a flange 128 at each end, made for example of cast iron which is very stiff and against Is resistant to impact and bending loads. The outer jacket 126 comprises two jacket halves 127, which are mirror images of a plane in which the axis of the outer casing 126 lies, as can be seen most clearly in FIG. 7, and each of which is provided with two longitudinal flanges 129 which extend radially from the respective seam 46 protrude outwards.

The knee 122 according to the second embodiment of the invention is manufactured in the following manner. One relatively elastic layer 38 made of plastic, both

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for example of polyvinyl chloride, which is omitted in FIG and has a thickness of approximately 5 to 8 mm, is formed or applied on the outer side of the core element 24, that was previously sintered. Then the two sheath halves 127 are placed on the plastic layer placed and with the help of screws 40, which in corresponding holes 44 in the longitudinal flanges 129 of the casing halves 127 are used, and nuts firmly connected to each other, which are screwed onto the screws 40, will. This leads to the result that the core element 24 on all sides and evenly over the plastic layer 38 is in contact with the casing halves 127. There are through holes in the end flanges 128 130, which serve the same purpose as the holes in the embodiment according to FIGS.

8 and 9 show a knee 222 which is a modification of the embodiment shown in FIGS. The knee 222 is similar to the knee 122 according to FIGS. to 7 with the exception that two sheath halves made of metal, the outer sheath 226 made of metal form, are welded together at the seams 246 of the casing halves, as for example represented by weld 248. This eliminates the need for the longitudinal flanges on the casing halves

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227, which is an advantage.

10 to 15 show embodiments of the invention in application to a straight piece of pipe. at each of these embodiments becomes a hollow cylindrical one, as in the embodiments of FIGS. 1 to 9 Core member 52 is formed by previously using a ceramic material that is a heat-resistant silicon carbide material comprises, is sintered with a binder such as silicon nitride or silicate. .

In the embodiment according to FIGS. 10 and 10, an outer casing 54 is a straight pipe section 50 is made of a thermoplastic synthetic resin which is the same synthetic resin as the outer one Sheath 26 of the first embodiment can act. Before the outer sheath 54 onto the core element 52 is applied, it is dimensioned as in the first embodiment so that its inner diameter is smaller than the outer diameter of the core member 52. The outer sheath is applied to the core element 52 in the same way Applied way as in the first embodiment. The end flanges 28 are attached to the outer jacket 54 attached in the same way as the first embodiment and made of the same material as the first

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Embodiment. Their construction is also the same.

In the one shown in Figs • straight pipe section 150 are two casing halves 156 of metal, which together form an outer shell 154 of metal, on the core member 52 in the same manner as. in the second embodiment according to FIGS. 5 to 7 appropriate. These shroud halves are similar in construction and function to the shroud halves 127 of FIG Embodiment according to FIGS. 5 to 7 with the exception that they are straight or stretched. To denote Parts or elements, the parts and elements. According to the 5 to 7 correspond, the same reference numerals are used in this embodiment, so that the Simplification, a further explanation is unnecessary.

14 and 15 show a straight pipe section 250, which is a modification of the and 13 is the straight pipe length 150 shown. Two sheathing halves 256 made of metal, which together have a Form outer sheath 254 made of metal, agree substantially with the sheath halves of the in Figs. and FIG. 9 shown embodiment. with the exception that the seams 246 of the outer casing

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halves 256 are welded to one another, for example via weld seams 248. This eliminates the need for longitudinal flanges on the casing halves 254.

Since each of the knees 22, 122 and 222 and the straight Pipe sections 50, 150 and 250 have a core element 24 or 52 made of ceramic material, they have a high Resistance to wear, heat and corrosion to wastewater flowing through the core element 24 or 52. Further these knees and pipe sections have a high compressive strength or a high pressure resistance, to which the high holding force of the outer sheaths 126, 226, and 254 that surround the core member 24. Due to the outer sheaths 26 and 54 made of synthetic resin and of the metal outer sheaths 126, 226, 154 and 254, the knees .and straight pipe sections not only have high resistance against external impact and bending stress, but they absorb these stresses essentially without cracking or breaking. The end flanges 28 and 128 are connected directly to the outer casing and not to the core element 24 so that too when the knee or the straight pipe section is connected to another pipe or a pipe connector is less likely to break the ceramic core elements. This has the consequence that the knees'22,

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122, and 222 and the straight pipe sections 50, 150 and 250 a significantly longer service life than conventional tubes, knees and Have elbows. Even if a core element breaks, the outer sheaths 26, 126 /. 226, 54, 154, 254 prevent it from breaking the core element. fragments of the core element are scattered.

When the knees and straight pieces of pipe are complete Made from ceramic material, it is due to the hardness and fragility of the ceramic Materials difficult to machine and grind to standard dimensions. Due to the Invention, however, these operations can be carried out very easily because the outer sheath and "the. End flanges are all made of synthetic resin or metal. . -

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Claims (1)

Claims 1.] Process for the production of a pipe or pipe connection piece, for example a straight pipe section, a knee or a bend, characterized in that Ceramic material in the tough state formed into a hollow cylindrical core element, that the core element is sintered that a tubular outer jacket made of thermoplastic resin with a. Inside diameter that is smaller than the outside diameter of the core element is, is heated and softened by the fact that the core element is inserted into the softened outer casing and that the outer shell is cooled, thereby making intimate contact with the core member. 2. Tube, characterized by a sintered, hollow cylindrical core element (24, 52) made of a ceramic Material and an outer jacket (26, 126, 226, 54, 154, 254) attached to the core member and consists of an easily machinable material with high mechanical strength. 3. Pipe according to claim 2, characterized in that the outer sheath (26, 54) made of thermoplastic synthetic resin is made. 609815/1026 .4. Pipe according to claim 2 or 3, characterized in that the outer jacket (26, 126, 226, 54, 154, 254) has an end flange (28, 128) at each of its two ends, made of the same thermoplastic synthetic. . resin how the outer sheath is made. 5. Tube according to .Anspruch 2, characterized in that the outer casing (126, 226, 154., 254) two casing halves (127, 227, 156, 256) which are mirror images of a plane in which the axis of the outer sheath is formed and arranged and each of which is one to the outside of the core member (24, 52) has complementary inside so that they can be connected to one another at seams (46, 246). 6. Tube according to claim 5, characterized by an elastic Layer (38) of plastic between the outer jacket (126, 226, 154, 254) and the core element (24, 52). 7. Tube according to claim 5 or 6, characterized in that. each of the casing halves (127, 227, 156, 256) has an end flange (128) at each of its two ends. 8. Pipe according to one of claims 5 to 7, characterized in that the casing halves (227, 256) at their 609815/1026 respective seams (246) are welded together. 9. Pipe according to one of claims 5 to 7, characterized in that each of the casing halves (127, 156) has two longitudinal flanges (129), which are of the respective Seam (46) protrude radially outward and serve to connect the sheathing halves to one another, 10. 'Tube according to one of claims 2 to 9, characterized in that. shows that it comprises a straight piece of pipe (50, 150, 250) ·. 11. Tube according to one of claims 2 to 10, characterized in that that it includes a knee (22, 122, 222). 12. Tube according to one of claims 2 to 11, characterized in that that it comprises an elbow (22, 122, 222). 60981S / 1026 Blank page