JP2608212B2 - Double disc wedge valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double disc type wedge valve described in the preamble of claim 1 of the appended claims.

[0002]

BACKGROUND OF THE INVENTION Valves of this type are generally known and have been manufactured and sold by the applicant for many years (Pamphlet No. 300, II / 82 "Refinery,
Petrochemical plants, process accessories and equipment for chemical plants-Program III "and DE-U-80 08 316). Flat oblong bodies with pipe bridges and circular body stop valves are known as single-disc and double-disc wedge valves (wedge-in-wedge theory), which, in the open position, stand upright stems and straight tubular passages. Is provided. In the case of the present invention, it is envisaged that a stop valve having a double disc wedge valve design will continue to be developed. Double disc wedge valves of this kind are used when it is necessary to seal the flow space of the valve in the open position of the valve with respect to the rest of the housing. This is especially the case when a gas stream containing the pollutants to be purified is involved. This is because if the flow space of the valve is not sealed to the rest of the housing, these substances will accumulate in the unenclosed part of the housing, causing overall blockage and inoperability of the valve. It is. Furthermore, valves of this kind are used for the same reasons in the case of dust-containing gases and highly contaminated liquid media, for example coal vaporization plants, amortization plants, chemical plants,
Used in pipelines, etc.

DE-C-868,543 discloses a double disc wedge valve, the pipe bridge of which is composed of an elastic corrugated pipe with a seal ring and a mechanical seal arranged on the end face. . The pipe bridge is housed in a tubular housing part of the valve disc, which at the same time serves to hold and guide the pipe bridge. In the open position of the valve, the mechanical seal is pressed against the sealing surface of the housing by the elasticity of the corrugated pipe and the expanding effect of the wedge device. This known construction has the disadvantage that the biasing force of the elastic corrugated pipe has to be set to a relatively large value in order to achieve sufficient tightness. As a result, when the pipe bridge is moved, its sealing ring slides along the opposite sealing seat of the valve housing with a relatively high contact pressure. Thus, there is considerable friction between the mutually contacting sealing surfaces, and considerable actuation force is required to switch the valve. In order to avoid this drawback, in DE-U-8008 316, the seal ring of the pipe bridge is suspended from the extension of the actuation rod for the valve disc and the return means consisting of rollers is provided on the seal ring and attached to the housing. It has been proposed to allow the roller to run along the raised ridge and to arrange the roller intake groove near the valve passage. This combined expansion and release device is intended to ensure a reliable pressing of the seal ring in the open position of the valve, while free movement of the pipe bridge along the two seal seats of the housing by actuation of the valve. This is to secure the sex. Furthermore, the shut-off plate of the valve disc is also provided with a roller, which in the closed position runs into the drive groove of the drive ridge, with minimal friction and damage to the sealing surface, especially in the case of high differential pressures. It has been proposed to allow movement of the blocking plate without. Specifically, the pipe bridge consists of two sealing rings and a compensating device interconnecting these sealing rings. The seal ring is dimensioned such that its diameter matches the diameter of the seal seat of the housing. The compensator is a corrugated elastic sheet metal ring, which is mounted so that when it is compressed or expanded, the adhering dust is automatically removed. In the open position of the valve, the seal ring is expanded by the wedge device. The wedge device comprises two laterally fixed housing parts within the valve housing and cooperates with each of the two disk wedges mounted on the seal ring in the open position of the valve. The pipe bridge further comprises a return device, each having four rollers, which are mounted symmetrically in pairs on the sealing ring with respect to its central axis. The roller travels along four drive ridges located in the valve housing, and the drive ridge is provided with a roller inlet groove near the valve passage. Each blocking plate also comprises four rollers running on said drive ridge. The width between the drive ridges and the depth of the retraction groove is such that, in the closed and open positions of the valve, both the seal ring of the pipe bridge and the shut-off plate are moved by the inner wedge and the housing wedge against the seal seat of the housing respectively. It is pressed in a gas-tight manner and is selected so as to be guided a predetermined distance from the sealing seat of the housing in the other switching positions. As is clear from the above description of known design examples, this is a relatively complex one. Many individual components must be mutually compatible with respect to their operational flow. Therefore, the production of the known double-disk wedge valve for pipe bridges requires extreme precision. In addition, known designs include multiple wear parts and parts that must be cleaned separately after a predetermined period of operation. In summary, in the known double-disc wedge valve having a pipe bridge according to DE-U-80 06 316, mechanical means (wedge mechanism, rollers, draw-in grooves, drive ridges) and mechanical forcing controls are provided. Depending on the position of the valve, it is used to press or lift the seal ring against the seal seat of the valve housing. Therefore, the mechanically forced control device described above impedes the adaptation to variable external conditions, especially different pressures in the pipeline in which the valve is installed. Furthermore, the known double disc wedge valve design example, as explained above, requires a large number of components which must be mutually compatible with respect to the flow of operation, which results in material and labor in manufacturing and assembly. Will consume. Correspondingly, maintenance is also expensive.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to further improve a double disc wedge valve of the type described above, i.e. the cooperation of the seal ring of the pipe bridge and the valve housing with a reduced number of parts. Between the seal seat,
In the open position of the valve a certain high degree of tightness is guaranteed,
At the same time, the aim is to achieve good adaptability to fluctuating external conditions, in particular fluctuating pressure in the valve passage.

[0005]

The object of the invention is achieved, in particular, by the characterizing features of claim 1. According to the structure of the present invention, the gas pressure in the valve housing is set higher than the gas pressure in the pipeline or the valve passage, respectively. This pressure acts on the circumferential recess, the sealing ring of the pipe bridge is pressed against the cooperating sealing seat, and the valve housing is sealed corresponding to the valve passage or pipeline in the valve open position. The pressure in the valve housing is set according to the pressure present in the valve passage. Preference is given to using scavenging steam as the pressurizing medium, which in each case is provided for cleaning the valve. The fact that the valve housing is at a higher scavenging steam pressure compared to the valve passage or pipeline respectively prevents the accumulation of dust or other gaseous or liquid medium flowing in the pipeline in the valve housing. Or minimized. Therefore, the consumption of scavenging steam for cleaning is minimal in the structure according to the invention. The aforementioned pressure regulation in the valve housing ensures a high degree of liquid tightness between the pipe bridge and the valve housing in the open position of the valve at all times, and it is not necessary to overcome excessive friction forces in operating the valve. That is due to the fact that the axial expansion of the seal ring by the gas pressure in the valve housing can be adapted to external conditions, in particular the pressure in the pipeline or in the valve passage. The sealing action of the compensator of the present invention is enhanced by the biasing force of the compensator, if appropriate for the particular application of the valve.

An embodiment of a double disc wedge valve with a pipe bridge according to the present invention will be described below in detail with reference to the accompanying drawings.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The double disc wedge valve 10 shown in FIGS. 1 and 2 comprises a valve housing 11, which comprises two pipe sockets 12, 13 and two sealing faces 14, 15. Between the sealing surfaces 14, 15 there is movably arranged a valve disc 16 consisting of two blocking plates 17, 18 with sealing rings 19, 20. The two blocking plates 17, 18 are internal wedges 21 which function as expansion members.
(Attached to the end of the operating rod 22 and fixedly connected thereto), the sealing surface 1 of the valve housing 11
It is designed to be pressed against 4 and 15. The blocking plates 17, 18 are extended by internal wedges 21, as known from the so-called "wedge-in-wedge theory". Adjacent to or adjacent to the valve disc 16 are two sealing rings 24, 25 and these sealing rings 24, 25.
Pipe bridge 23 consisting of a compensator 26 interconnecting
And are arranged. Compensation device 26 is the inner pipe part
27 and an outer pipe portion 28 extending coaxially therewith. The outer pipe portion 28 is, for example, welded (annular welded portion 29,
30), it is fixedly joined to the two seal rings 24, 25, and a recess 31 extending in the circumferential direction is formed. On the other hand, the inner pipe portion 27 is a hollow cylinder,
In essence, it has no recesses, so there is no flow loss due to the recesses. Further, the inner pipe portion 27 is fixedly joined to only one of the two seal rings 24, 25, that is, the seal ring 25 (annular weld 32). Inner pipe part 27
Is axially movable with respect to the other seal ring 24 and the axial play between the seal ring 24 and the inner pipe section 27 is between about 1.0 mm and about 5.0 mm. The arrangement of the inner pipe section 27 with respect to the two seal rings 24, 25 is such that the inner surface of the inner pipe section 27 is aligned with the respective inner surfaces of the seal rings 24, 25 and is substantially closed in the open position of the valve. The flow path is not formed. 1 and 2, the valve is shown in the closed position. In the valve housing 11, that is, in the interior 33 thereof,
The valve housing 11 is liquid-tight to the outside so that the gas pressure is set higher than the pressure in the valve passage or in the pipeline (not shown in FIGS. 1 and 2) in the open position of the valve. Has become. Therefore, the operating rod 22 must also be introduced into the valve housing 11 in a liquid-tight manner. A fitting 34 for communicating with a pressure gas source, particularly a scavenging steam source (not shown) is provided in the valve housing 11. In the embodiment shown in FIGS. 1 and 2, the seal surfaces of the seal rings 24 and 25 and the seal surface of the valve housing 11
Reference numerals 14 and 15 each extend parallel to the operating direction of the valve, and are subjected to a well-known hardening treatment or strengthening treatment in order to increase their wear resistance.

Furthermore, a circumferential recess 31 of the outer pipe portion 28
Extends substantially perpendicularly to the outer surface of the inner pipe section 27, so that the gas pressure in the housing interior 33 has a complete effect on the seal rings 24, 25 via the circumferential recess 31; Thus, the seal rings 24 and 25 are expanded in the axial direction. The axial expansion of the sealing rings 24, 25 is made possible on the one hand by the circumferential recess 31 and on the other hand by the axial play between the inner pipe section 27 and one of the sealing rings 24. Therefore, the pipe bridge 23 is
Inner and outer pipe sections serving as two sealing rings 24, 25 on the one hand and as compensator 26 on the other
27, 28, thereby forming an annular box 35. The annular box 35 or the annular space between the inner and outer pipe portions 27, 28 is filled with a heat insulating material, especially glass wool, rock wool or the like. This filler not only provides thermal insulation, but also prevents the flowing medium from flowing into the particular annular space defined between the inner and outer pipe sections 27, 28. The clogging of the annular space 35 by the flowing medium or, in the case of a gas stream, by dust particles or similar deposits has a significant effect on the operation of the compensator 26 after a long period of operation. It has one function.

Other structural details of the double-disc wedge valve shown in FIGS. 1 and 2 are known, and a detailed description of these components is omitted since these components do not form an integral part of the present invention. I do.

[0010] Basically, an adjustable pressure limiting valve is provided so as to cooperate with the inside of the valve housing 11, that is, with the inside 33 of the housing, so that the pressure inside the inside 33 of the valve housing 11 does not exceed a predetermined pressure. It is possible to This predetermined pressure is set so as to ensure a sufficiently tight and reliable seal between the seal rings 24, 25 and the cooperating seal seats 14, 15 of the valve housing 11 in the valve open position.

Further, with respect to the illustrated embodiment, in actual use, the pressure in the annular space 35 between the inner and outer pipe sections 27, 28 will be slightly lower than in the valve passage or pipeline, but this phenomenon Is limited by the area of axial play between the seal ring 24 and the inner pipe section 27, or by the resulting "water pump effect" which results in a slightly higher flow rate in the valve passage or pipeline. Note that this occurs when As a result, the positive pressure present in the interior 33 of the valve housing 11 acts on the two sealing rings 24, 25 with a further increased effect, so that the sealing rings 24, 25 expand axially.

FIGS. 3 and 4 show an embodiment according to the invention as claimed in claim 7 in a schematic partial sectional view, in which 27 is an inner pipe section and 28 is an outer pipe section. 24, 25 are seal rings, 33 is the interior of the valve housing 11 having a positive gas pressure, 36 is an annular insert of reinforced steel or the like, 29, 30, 32 are annular welds. The faces of the seal rings 24, 25 and the outer pipe section 28, which face each other axially on the sides of the valve housing (FIG. 3), are 37
Indicated by When the pressure within the valve housing interior 33 is positive, the surface 37 serves to axially expand the outer pipe section 28 and provides a seal near the annular insert 36. In the embodiment shown in FIG. 4, the sealing connection between the smooth outer pipe section 28 and the lower sealing ring 24 is made by means of an annular ring which, under the conditions mentioned above, has two sealing rings 24. , 25 relative axial movement is possible.

[Brief description of the drawings]

FIG. 1 is a partial cutaway view of a double disc wedge valve having a pipe bridge according to the present invention.

2 is a cross-sectional view of the double disc wedge valve taken along line II-II of FIG.

FIG. 3 is a schematic partial cross-sectional view showing another embodiment of the present invention.

FIG. 4 is a schematic partial sectional view showing still another embodiment of the present invention.

[Explanation of symbols]

 10 Double disc wedge valve 11 Valve housing 14,15 Sealing surface (seal seat) 16 Valve disc 22 Operating rod 23 Pipe bridge 24,25 Seal ring 26 Compensator 27 Inner pipe part 28 Outer pipe part 31 Recess 33 Inside the housing

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Norbert Marx, Federal Republic of Germany, 5160 Duren, Monschauer Landstraße 49 (72) Inventor Gunther Negra, Federal Republic of Germany, 5180 Eschweiler, Neusener Strasse 60 (56) ) References JP-A-55-107175 (JP, A) JP-A-63-225768 (JP, A) JP-A-59-6647 (JP, A)

Claims (8)

(57) [Claims] 1. A valve for selectively closing a connected piping passage.
The valve (16) is connected to the valve disc (16) and the valve is open.
A valve passage similar to the piping passage in the valve housing
(11) a pipe bridge (23) formed therein;
Valve disc (16) is moved by the operating rod (22), wherein
2 with pipe bridge (23) connected by compensator (26)
One seal includes ring (24, 25), the sealing ring (24,2
5) is a double disc that is pressed against the seal seats (14, 15) of the valve housing (11) in the valve open position and the compensator (26) includes a pipe portion having a circumferentially extending recess (31). In the wedge valve (10), the pipe portion coaxially surrounds an inner pipe portion (27) fixed to only one of the two seal rings and movable in the axial direction with respect to the other seal ring. and extends as the outer pipe section (28) has, and the gas pressure inside (33) of the valve housing (11), in the valve open position
A double disc wedge valve, wherein the pressure can be set higher than the pressure in the valve passage. 2. An inner pipe section (27) and an outer pipe section (2).
The wedge valve according to claim 1, wherein the annular space (35) between the wedge valve and the wedge valve is filled with a heat insulating material such as glass wool or rock wool. 3. The valve housing in which the operating rod (22) is liquid-tight.
The valve housing (11) inserted into the (11) and having a fitting (34) for communicating with a pressure gas source such as a scavenging gas source. Double disk type wedge valve described in 2. 4. The sealing surface of the seal ring (24, 25) on the one hand and the sealing surface of the cooperating seal seat (14, 15) on the other hand are respectively parallel to the valve operating direction, that is, the valve passage. The double-disk wedge valve according to any one of claims 1 to 3, wherein the wedge valve extends perpendicular to a longitudinal axis of the wedge valve. 5. A circumferential recess (31) in the outer pipe section (28).
5. The double-disc wedge valve according to claim 1, wherein the wedge valve extends close to the outer surface of the inner pipe section. 6. A pipe bridge (23) comprising two seal rings (24, 25) and inner and outer pipe portions (27) located between said seal rings and functioning as said compensator (26). ) Is defined, and the inner surface of the inner pipe portion (27) is aligned or flush with the inner surfaces of the two seal rings (24, 25). 2. The double disc wedge valve according to claim 1. 7. Sealing surface of two seal rings (24, 25)
There are formed respectively, along its outer peripheral edge, or, 該Shi
Along the outer perimeter of the ring
Any of claims 1 to 6 , characterized in that
2. The double disc wedge valve according to claim 1 . 8. A sealing surface of the seal ring (24, 25)
Is extended along its outer periphery and is a hardened steel
An annular insert (36) made of reinforced steel
The datum according to claim 7, wherein the da
Bull disc type wedge valve .