Pipe comprising a pressure relief valve

Abstract

A pipe is provided for transporting a viscous fluid, including a pressure relief valve provided with a sealing element which separates the inside of the pipe from a discharge line and is designed to release the discharge line in the event of predetermined excess pressure. A surface of the sealing element, facing a Miler chamber of the pipe, is associated with the pipe in such a manner that the surface is flown around by a flow of the viscous fluid circulating through the pipe when in operation, and the sealing element is fixed in the closed position by a rod, the rod being displaced by the predetermined excess pressure such that the thus connected sealing element releases the discharge pipe.

Claims

1. A pipe for transporting a viscous fluid, comprising: a pressure relief valve including a body and a sealing component, said pressure relief valve separates an interior of the pipe from an outflow pipeline and unblocks the outflow pipeline in the event of a predetermined overpressure, said sealing component including a disc and a seal attached to said disc that forms a seal with said body, a face of the sealing component is arranged in the pipe through which the fluid flows, wherein the face of the sealing component facing the interior of the pipe is shaped to generally conform to the contour of the inner side of the pipe wall and faces the interior of the pipe and is flush with an inside surface of a wall of the pipe such that the face is rinsed by the viscous fluid during operation, wherein the sealing component is fixed in the closed position by a linkage, and said linkage is displaced by the predetermined overpressure, so that the sealing component connected thereto moves away from the wall of the pipe and unblocks the outflow pipeline.

2. The pipe according to claim 1, wherein the linkage is fixed by a shearing component, and wherein the shearing component releases the linkage for displacement in the event of the overpressure, which overcomes the shear resistance.

3. The pipe according to claim 1, wherein the linkage is fixed by a spring.

4. The pipe according to claim 1, wherein the temperature of the pipe can be controlled by means of thermal insulation and/or by means of heating or cooling elements.

5. The pipe according to claim 4, further comprising at least one heat transfer medium channel in the region of the pressure relief valve.

6. The pipe according to claim 1 wherein the pressure relief valve is clamped into a holder in the inner wall of the outflow pipeline.

7. The pipe according to claim 1, wherein the pipe is a heat exchanger.

8. The pipe according to claim 1, wherein the relief diameter of the sealing component D and the cross-sectional width of the linkage b are chosen with reference to the modulus of elasticity E of the linkage and the predetermined overpressure p in accordance with the formula D/b=Mx(p/E)−0.652, where M is between 0.003 and 0.0182.

9. The pipe according to claim 1, wherein the linkage is fastened in a hinged manner at one end on the sealing component or at the other end on a holder of the pressure relief valve.

10. The pipe according to claim 1, wherein the linkage or the sealing component is in functional connection with a sensor, which detects a deflection or a displacement of the linkage or sealing component, wherein the sensor preferably delivers a signal, which differentiates between the open and closed state of the valve, or a signal which delivers transitions between these states.

11. The pipe according to claim 1, wherein the linkage comprises a buckling rod within said outflow pipeline.

12. The pipe according to claim 1, wherein the sealing component has a diameter that is less than an internal diameter of the outflow pipeline such that the sealing component is movable within the outflow pipeline.

13. A pipe for transporting a viscous fluid, comprising: a pressure relief valve including a body and a sealing component, wherein said pressure relief valve separates an interior of the pipe from an outflow pipeline and unblocks the outflow pipeline in the event of a predetermined overpressure in the pipe, said sealing component including a disc and a seal attached to said disc that forms a seal with said body, a face of said sealing component faces the interior of the pipe and is flush with an inside surface of a wall of the pipe through which the fluid flows, wherein the face of the sealing component facing the interior of the pipe is shaped to generally conform to the contour of the inner side of the pipe wall and is rinsed by the viscous fluid of the pipe during operation; and a buckling rod attached to said sealing component, wherein said buckling rod is configured to bend or buckle in the event of the predetermined overpressure, wherein said sealing component is fixed in a closed position by said buckling rod, and said buckling rod is displaced to a second position by the predetermined overpressure, causing the sealing component to move away from the wall of the pipe and unblock the outflow pipeline.

14. The pipe according to claim 13, wherein said buckling rod is fastened in a hinged manner at one end on the sealing component or at the other end on a holder of the pressure relief valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is illustrated further by means of the following figures and examples, without being limited to these specific embodiments of the invention.

Figures

(2) FIG. 1 shows a pipe as connecting piece (1), through which fluids can be conveyed. A supply pipeline (2) is shown, the temperature of which is controlled with a double jacket as insulation (3), so that the fluid temperature and viscosity can be kept constant. The double jacket (3) located around the supply line (2) can be connected to the heat transfer medium bores (4) of the connecting piece, so that the same heat transfer medium (5) can be conveyed between the double jacket (3) of the supply line (2) and the distribution part (1).

(3) A bore (6) for accommodating a pressure relief valve (7) is provided in the connecting piece (1). The cylindrically constructed pressure relief valve (7) is sealed with respect to the tube interior (9) by means of seals (8), which are inserted into a groove on the outer circumference. The seals (8) can be constructed in a different shape and configuration, centred on the respective use case. The cylindrical pressure relief valve (7) is provided with a flange (10) at the upper end and is connected via screws and bolts (11) to the connecting piece (1). The upper flange (10) is constructed in such a manner that a lid (12) is let into the pressure relief valve (7), wherein a holder is attached on the lid (12) as guide sleeve (13). This holder (13) is used for guiding and accommodating the linkage (14), wherein the linkage (14) is connected to the holder (13) in a positive-fitting manner by means of a bolt (15). The holder (13) is constructed in such a manner that a bonding and securing surface (16) is constructed at the lower end of the holder (13). A pressure relief spring (17) sits on this bonding and securing surface (16), which is attached over the outer circumference of the linkage (14). To support the pressure relief spring, the linkage (14) is realised with a bonding and securing surface (18) in accordance with the dimensioning of the pressure relief spring length. The sealing component sits at the lower end of the linkage (14) in the form of a disc (19), wherein a seal (20) is attached on the circumference of the disc (19) for sealing with respect to the pipe interior (9). The seal (20) can be attached on the outer circumference of the seal (20) or else also on the planar surface of the disc. In this case, the pressure relief valve (7) is realised in such a manner that the seal is sealed with respect to the interior. In the case of penetrating overpressure, the disc (19) is pushed upwards by the interior of the pressure relief valve (7), wherein the pressure relief spring (17) is compressed in accordance with the dimensioned spring constant and the overpressure in the interior (9) is dissipated outwards via the pressure relief valve interior (21) and the flange (22) and the outflow pipeline (23) thereof.

(4) FIG. 2 illustrates the pipe of FIG. 1 in the pressure-relieved open state.

(5) FIG. 3 illustrates a pressure relief valve (7) according to FIG. 1 and FIG. 2, wherein the linkage (14) is connected in the holder (13) by means of a shear bolt (24) dimensioned in accordance with the opening pressure. If an overpressure arises in the fluid interior, the shear bolt (24) is sheared off, the linkage (14) strikes against the lower end of the guide sleeve (13) and unblocks the opening in the interior (9) for reducing the pressure by means of the travel of the linkage (14) and the upper part of the linkage passes through the lid (12) of the pressure relief valve (7) (illustrated in FIG. 4—number 25).

(6) FIG. 4 illustrates the pipe of FIG. 3 in the pressure-relieved open state.

(7) FIG. 5 illustrates a pressure relief valve (7) according to FIG. 1 and FIG. 2, wherein the linkage (14) is constructed in the holder (13) as a buckling rod (26) and is non-releasably connected to the holder (13). The rod (26) or the sealing component is preferably in functional connection with a sensor (29), which detects a deflection or a displacement, so that a signal, which differentiates between the open and closed state of the valve. The connection of the buckling rod (26) to the holder (13) can also take place in an articulated manner. If an overpressure arises in the pipe interior (9), the buckling rod (26) dimensioned to the opening pressure is deformed. The sealing component as disc (19), which is securely connected to the buckling rod (26), is pushed back by the deformed buckling rod (26) and unblocks the pipe interior (9) for the outflow of the fluid in overpressure.

(8) FIG. 6 illustrates the pipe of FIG. 5 in the pressure-relieved open state.

(9) FIG. 7 illustrates the detail of the spring-loaded linkage (14) in the closed state of the pressure relief valve (7).

(10) FIG. 8 illustrates the linkage of FIG. 7 in the pressure-relieved state.

(11) FIG. 9 illustrates the detail of the linkage (14), which is connected to the shear bolt (24), in the closed state of the pressure relief valve (7).

(12) FIG. 10 illustrates the linkage of FIG. 9 in the pressure-relieved state and the sheared shear bolt (24).

(13) FIG. 11 illustrates the detail of the buckling rod (26), which is connected to the holder (13), in the closed state of the pressure relief valve (7).

(14) FIG. 12 illustrates the linkage of FIG. 11 in the pressure-relieved state and the buckled buckling rod (26).

(15) FIGS. 13 a and b show to mutually perpendicular side views of a pipe with the pressure relief valve with buckling rod in the closed position. The contour of the sealing component is realised conformly to the contour of the pipe inner wall, so that absolute freedom from dead space is achieved.

(16) FIGS. 14 a and b illustrate the pipe of FIG. 13 in the pressure-relieved open state.

(17) FIGS. 15 a and b show to mutually perpendicular side views of a pipe with the pressure relief valve with buckling rod in the closed position.

(18) FIG. 16 shows the open position. The contour of the sealing component is realised conformly to the contour of the pipe inner wall, so that absolute freedom from dead space is achieved. In addition, the outflow pipeline is provided at the side, so that in the open state of FIG. 16, the valve interior with the linkage is sealed by means of the sealing component and remains fluid-free.

(19) FIG. 17 shows a pipe with a pressure relief valve (7) with a linkage (14) in a buckling-rod design, which is connected in an articulated manner via linkage (27) to the holder (13) and the sealing component (19). FIG. 17a shows the sealed state of the pipe and FIG. 17b shows the open state with buckled linkage. The sealing component is in the form of a tappet, which is secured via guide components (28) in the valve (7) for guiding during the opening procedure and is additionally secured against lateral displacement.

(20) FIG. 18 shows a pipe with a pressure relief valve according to FIG. 17 in a side view. The buckling-rod linkage is shaped rectangularly in cross section and is wider in the view of FIG. 18 than in FIG. 17. During the buckling process, the buckling takes place along the narrow side of the cross section (FIG. 17b).

(21) FIG. 19 is a further side view of a pipe with a pressure relief valve, wherein in contrast with FIG. 18, the outflow pipeline (23) is attached at the side.

(22) FIG. 20 shows a buckling rod with a linkage (27) at the upper end and a rounding at the lower end for articulated accommodation in a holder or in a sealing component. Characteristic features of the buckling rod are the length (L), the cross-sectional height (h) and the cross-sectional width (b). Two side views, which are rotated 90° with respect to one another, are shown (FIGS. 20a and 20b).

(23) FIG. 21 shows an enlargement of the linkage and the accommodation thereof in the valve or the sealing component, as illustrated in FIGS. 17 and 18.

(24) FIG. 22 shows the sealing of a pipe by means of a sealing component (19), which is present conformly to the contour of the interior of the round pipe wall. The valve (7) is likewise realised in a conform manner. Sealing components (20 and 8) between the sealing component and the valve or between the valve and the pipe wall are illustrated. The relief diameter (D) of the face exposed by the sealing component is identified. In addition to the radial seal design illustrated in FIG. 22, it is also possible to realise the seal as an axial seal.

(25) FIG. 23 shows an illustration of the parameter D (relief diameter) over b (cross-sectional width of the linkage) for p (triggering pressure) over E (E modulus of the linkage material) under optimum conditions for square, round and rectangular linkage cross sections and also the minimum value for D/b.

DETAILED DESCRIPTION

Example 1

(26) According to this example, a pipe is used with a pressure relief valve with a buckling rod, as illustrated in FIG. 5. During operation, this pipeline was tested with a cellulose/NMMO/water solution (cellulose: 12.9%, NMMO 76.3%, water 10.8% all % are % by weight) at a temperature of 90° C. and a pressure of 30 bar.

(27) The solution was introduced into the first heat exchanger under pressure by means of a pump. A filter was located at the end of the second heat exchanger, in order to maintain the pressure in the pipeline. The two heat exchangers were connected to the pipe according to the invention with the pressure relief valve as connecting piece.

(28) During the test operation, it was not possible to detect any irregular temperatures and pressures. In the case of a simulated overpressure of 100 bar, the pressure relief valve opened, as a result of which the pressure fell below normal operating pressure.

(29) Fluid samples were taken at regular distances, investigated by means of DSC analysis with regards to the thermal stability thereof and compared with the stability of “fresh” cellulose/NMMO/water solution. Even after a term of a plurality of days, no reduction of the thermal stability of the cellulose/NMMO/water solution could be detected in the region of the pressure relief valve compared to “fresh” solution.

Example 2

(30) A polymer solution—to be used as a spinning solution and with the following composition—was transferred from spinning solution production through to processing of the same at a spinning machine through a heat-exchanger pipeline system consisting of heat exchangers and the pipes according to the invention as distribution pieces. The spinning compound consisting of a mixture of cellulose of the type MoDo Crown Dissolving DP 510-550 and Sappi Saiccor DP 560-580 were produced continuously with the following composition, cellulose 12.9%; amine oxide (NMMO-N-methylmorpholine N-oxide) 76.3%; water 10.8%.

(31) The solution production took place after aqueous enzymatic pretreatment and suspension production by evaporating excess water under vacuum in a continuously perfused reaction vessel at a temperature of 97 to 103° C. had taken place. Known stabilisers were added to stabilise the solvent NMMO/water. The stabilisation of the cellulose solution takes place, as is known, using propyl gallate. For safety-concious solution production, the heavy metal ion content is checked and a value of 10 ppm as sum parameter (made up of metal ions and noble metal ions) is not exceeded.

(32) The density of the solution produced is 1,200 kg/m.sup.3 at room temperature. The zero shear viscosity of the spinning compound set by means of the cellulose mixing components can be up to 15,000 Pas, measured at 75° C. Depending on the processing temperature chosen in the spinning process, the zero shear viscosity can shift in the range from 500 to 15,000 Pas. Due to the structurally viscous behaviour of the spinning solution, the viscosity falls for spin shear rates, depending on the chosen processing temperature, to a range of below 100 Pas and is likewise heavily dependent on the cellulose concentration in the spinning solution.