DE102015220932A1 - High-pressure mechanical seal assembly - Google Patents

Abstract

The invention relates to a mechanical seal assembly (1) comprising a mechanical seal (10) with a rotating seal ring (2) and a stationary seal ring (3) defining therebetween a sealing gap (4), a first throttle (5) comprising a first one A throttle ring (51), wherein on a inner circumference of the first throttle ring (51) a first throttle point (50) is provided, a second throttle (6) comprising a second throttle ring (61), wherein on the inner circumference of the second throttle ring (61) a second throttle body (60) is provided, wherein the first throttle (5) in the axial direction (XX) between the mechanical seal (10) and the second throttle (6) is arranged, and wherein the first throttle (5) is provided floating.

Description

The present invention relates to a high pressure mechanical seal assembly for high pressures between 40 and 150 x 10 ⁵ Pa, which are used for example in pumps of pumping stations of oil pipelines.

Mechanical seal assemblies are known in the prior art in various configurations. Oil is transported for example in pipelines over several 1000 km, with pumping stations being provided at predetermined intervals. The oil pipelines are often conducted over rough and uninhabited terrain, so that the pumping stations are unmanned and often difficult to reach. Due to the high pressures, the highest demands are placed on the mechanical seal assemblies used in the pumps of the oil pipelines. It is important to avoid leaking oil from the pump due to failure of a mechanical seal assembly and pollute the environment. So far, so-called "tandem mechanical seals" are used in the prior art, with two mechanical seals are connected in succession in the axial direction. Should the first mechanical seal fail, the second mechanical seal is still present as redundancy, which prevents oil from escaping from the pump. This principle has basically been granted, however, the use of such tandem mechanical seal assemblies is very costly.

It is an object of the present invention to provide a mechanical seal assembly, especially for high-pressure applications, which with a simple structure and simple, cost-effective manufacturability and high pressures, z. B. in oil pipelines or the like., Can seal. This object is achieved by a mechanical seal assembly with the features of claim 1, the dependent claims show preferred developments of the invention.

According to the invention, the mechanical seal assembly comprises a mechanical seal with a rotating seal ring and a stationary seal ring, which define a sealing gap between them. Furthermore, the mechanical seal assembly comprises a first throttle with a first throttle ring, wherein a first throttle point is provided between the first throttle ring and a rotating component. Furthermore, a second throttle is provided, which comprises a second throttle ring, wherein a second throttle point is provided between the second throttle ring and the rotating component. In this case, the first throttle is arranged in the axial direction between the mechanical seal and the second throttle. Furthermore, the first throttle ring is provided floating on the rotating component. The floating arrangement of the first throttle ring makes it possible to prevent, in particular when shaft movements occur in the radial direction, that the first throttle ring comes into contact with the shaft or a rotating component, such as a shaft sleeve. Furthermore, by providing two throttles connected in series in the axial direction, a high level of safety can be ensured even in the event of failure of the mechanical seal which is arranged on the product side of the mechanical seal arrangement. Thus, according to the invention, in comparison with tandem mechanical seal assemblies, an expensive mechanical seal can be replaced by two inexpensive throttles without thereby reducing safety in the event of failure of the close-to-product mechanical seal.

Preferably, the first throttle on a bandage, which is arranged on the outer circumference of the first throttle ring. In this case, a shrink connection is provided between the first throttle ring and the bandage. The bandage is thus shrunk onto the first throttle ring, whereby a strength of the first throttle can be significantly increased. As a result, even if the mechanical seal fails, the first throttle can withstand a high pressure between 40 and 150 × 10 ⁵ Pa at the first throttle.

More preferably, the mechanical seal assembly comprises a spring element which exerts an axially acting force on the first throttle. This ensures in particular that the first throttle gap on the inner circumference of the first throttle ring remains as constant as possible under all operating conditions. A spring force of the spring element in the axial direction is equal to or greater than a weight of the first throttle. Thus, it is prevented in particular that the first throttle ring comes into contact with the rotating component due to the acting weight force.

More preferably, the mechanical seal assembly comprises a stationary component with a recess, wherein in the recess, the first throttle is arranged. As a result, an easy-to-install first throttle is obtained in particular.

Particularly preferably, the first throttle ring on an inner circumference on a side facing the stationary component on a recessed, annular circumferential shoulder. This prevents that during operation, an edge of the stationary component is pressed against the first throttle ring, resulting in undesirable damage or failure, z. B. a shift, could lead to the first throttle ring.

According to a further preferred embodiment of the invention is also the second Throttling ring of the second throttle provided floating on the rotating component. This results in the same advantages as in the floating provided first throttle ring.

The first throttle ring is preferably made of PEEK with carbon fibers introduced. This composite material has the particular advantage that certain lubricating properties and very high strengths are present, so that even at a start or a contact of the rotating component, a sliding of the first throttle ring on the rotating component is possible.

In order to prevent co-rotation of the first throttle with the rotating component, a first anti-rotation device is preferably provided. The first rotation lock is particularly preferably a pin or a plurality of pins, which are aligned in the axial direction and are fixed to a stationary component.

More preferably, the throttle points on the first and second throttle are provided such that the second throttle point has a narrower throttle gap than the first throttle point. Thus leakage of a medium to be sealed into the environment can be minimized or completely avoided.

The mechanical seal assembly according to the invention is used in particular in pumps. The pumps are particularly preferably designed for conveying oil in pipelines and a delivery pressure of the pumps is in the range between 40 and 150 × 10 ⁵ Pa.

Hereinafter, a preferred embodiment of a mechanical seal assembly according to the present invention will be described in detail with reference to the accompanying drawings. In the drawing is:

1 a schematic partial sectional view of a mechanical seal according to a preferred embodiment of the invention.

How out 1 it can be seen comprises the mechanical seal assembly 1 a mechanical seal 10 with a rotating seal ring 2 and a stationary slip ring 3 , Between the rotating seal ring 2 and the stationary seal ring 3 is a sealing gap 4 intended.

The mechanical seal assembly 1 seals a product page 11 from an atmosphere side 12 from.

The mechanical seal assembly 1 is on a shaft sleeve 7 arranged, which with a wave 8th connected is. The rotating seal ring 2 is about a driver element 20 with the shaft sleeve 7 connected and thus rotates together with the shaft 8th and the shaft sleeve 7 ,

The stationary seal ring 3 is on a housing 9 via an intermediate component 90 fixed.

The mechanical seal assembly 1 includes next to the mechanical seal 10 a first throttle 5 and a second throttle 6 , The first throttle 5 is in the axial direction XX between the mechanical seal 10 and the second throttle 6 arranged.

How out 1 can be seen, comprises the first throttle 5 a first throttle ring 51 and a bandage 52 , Between the first throttle ring 51 and the bandage 52 is a shrink connection 53 intended. Thus, the bandage 52 on the first throttle ring 51 shrunk, leaving a stable annular first throttle 5 is provided. A first throttle point 50 is on the radially inner circumference of the first throttle ring 51 between the first throttle ring 51 and the shaft sleeve 7 intended.

How farther 1 can be seen, comprises the second throttle 6 only a second throttle ring 61 , A second throttle point 60 is at an inner circumference of the second throttle ring 61 between the second throttle ring 61 and the shaft sleeve 7 intended.

The first throttle 5 is in a recess 13 a housing component 14 intended. By means of an anti-twist device 15 in the form of one or more pins prevents the annular first throttle 5 together with the shaft sleeve 7 rotates. In the same way is a second rotation 16 at the second throttle 6 intended.

Furthermore, there are several spring elements 17 provided, which a spring force F in the axial direction XX to the first throttle 5 exercise. This will be the first throttle 5 to the bottom of the recess 13 in the housing component 14 pressed.

In this embodiment, the first throttle 5 and the second throttle 6 floating on the shaft sleeve 7 stored. D. h., By the floating bearing is prevented during movements of the shaft 8th , in particular in the radial direction, the first throttle 5 and the second throttle 6 the shaft sleeve 7 touch. The floating bearing thus allows radial compensatory movements of the first throttle 5 and the second throttle 6 ,

The mechanical seal assembly according to the invention 1 is set up to seal high pressures between 40 and 150 × 10 ⁵ Pa. In normal operation, the seal is done so high Press over the mechanical seal 10 , Should, however, the mechanical seal 10 can fail, the inventive Gleitringdichtungsordnung 1 with the first and second throttle 5 . 6 prevent the medium to be sealed from the product side 11 to the atmosphere side 12 arrives. As a result, for example, in an application of the mechanical seal assembly 1 In a pump for an oil pipeline pollution of the environment can be prevented by escaping oil.

In case of failure of the mechanical seal 10 the oil flows under high pressure to the first throttle point 50 , Because the first throttle 5 the first throttle ring 51 with the shrunk bandage 52 can, the first throttle 5 withstand such high pressures. Due to the sudden pressure increase in the area before the first throttle 5 It could also cause radial movements of the shaft 8th and thus also the shaft sleeve 7 come. However, because the first throttle 5 floating on the shaft sleeve 7 is stored, the first throttle 5 Join compensatory movements in the radial direction, so that damage to the first throttle 5 can be avoided by the sudden increase in pressure.

Because the second throttle 6 is also floating, this also applies to the second throttle.

The area 18 before the first throttle 5 is about a hole 91 in the case 9 with a pressure sensor 19 connected. The pressure sensor 19 For example, in the case of an unmanned pumping station, the oil pipeline may be connected to a monitoring center.

Although passes through the first throttle point 5 a certain amount of medium to be sealed then up to the second throttle 6 , However, since the second throttle 60 is made narrower than the first throttle point 50 , may leak the medium to the atmosphere side 12 almost completely avoided over a period of time. The leakage after the throttle point 50 can be via a drainage line 21 be discharged safely and at low pressure. The optionally via the second throttle point 60 leaking amounts of medium to be sealed in the atmosphere side 12 are acceptable.

Alternatively, the second throttle 60 be chosen so narrow that virtually no leakage to the atmosphere side 12 occurs.

The spring elements 17 Make sure that the first throttle 5 not due to its own weight on the shaft sleeve 7 rests. In this case, a spring force F of the spring elements in total is greater than a weight of the first throttle 5 , This will ensure that the first throttle 5 remains at its desired operating position, in which circumferentially completely in each case the first throttle point is maintained annularly.

The throttle ring 51 the first throttle 5 has an inner periphery at one to the housing component 14 directed side a recessed, annular paragraph 54 on. Through this paragraph 54 prevents damage to the first throttle ring during operation 51 occurs, which could occur when the first throttle ring 51 in the axial direction XX against the housing component, in particular a radially inner edge on the housing component 14 is pressed.

Thus, the mechanical seal assembly according to the invention allows a seal of very high pressures and is preferably used in unmanned or difficult to access pumps.

LIST OF REFERENCE NUMBERS

1

The mechanical seal assembly

2

rotating seal ring

3

stationary sliding ring

4

sealing gap

5

first throttle

6

second throttle

7

shaft sleeve

8th

wave

9

casing

10

Mechanical seal

11

product page

12

atmospheric side

13

recess

14

housing component

15

first anti-twist device (pin)

16

second anti-twist device (pin)

17

spring element

18

Area before the first throttle

19

pressure sensor

20

dogging

21

drainage line

50

first throttle point

51

first throttle ring

52

bandage

53

shrink connection

54

recessed heel on the first throttle ring

60

second throttle point

61

second throttle ring

90

between component

91

drilling

F

spring force

X X

axially

Claims (9)

Mechanical seal assembly ( 1 ), comprising: - a mechanical seal ( 10 ) with a rotating sliding ring ( 2 ) and a stationary sliding ring ( 3 ), which between them a sealing gap ( 4 ), - a first throttle ( 5 ), comprising a first throttle ring ( 51 ), wherein on an inner circumference of the first throttle ring ( 51 ) a first throttle point ( 50 ), - a second throttle ( 6 ), comprising a second throttle ring ( 61 ), wherein on the inner circumference of the second throttle ring ( 61 ) a second throttle restriction ( 60 ), the first throttle ( 5 ) in the axial direction (XX) between the mechanical seal ( 10 ) and the second throttle ( 6 ), and - wherein the first throttle ( 5 ) is provided floating. Arrangement according to claim 1, wherein the first throttle ( 5 ) a bandage ( 52 ), which on the outer circumference of the first throttle ring ( 51 ) is provided, wherein between the first throttle ring ( 51 ) and the bandage ( 52 ) a shrink connection ( 53 ) is provided. Arrangement according to one of the preceding claims, further comprising at least one spring element ( 17 ), which has an axial force (XX) (F) acting on the first throttle ( 5 ), wherein a spring force (F) greater than or equal to a weight of the first throttle ( 5 ). Arrangement according to one of the preceding claims, further comprising a housing component ( 14 ) with a recess ( 13 ), the first throttle ( 5 ) in the recess ( 13 ) is arranged. Arrangement according to claim 4, wherein the first throttle ring ( 51 ) on an inner circumference at one of the housing component ( 14 ) directed a recessed, annular shoulder ( 54 ) having. Arrangement according to one of the preceding claims, wherein the second throttle ring ( 61 ) is arranged floating. Arrangement according to one of the preceding claims, wherein the first throttle ( 5 ) a first anti-rotation device ( 15 ) having. Arrangement according to one of the preceding claims, wherein the second throttle point ( 60 ) of the second throttle ( 6 ) has a narrower throttle gap than the first throttle restriction ( 50 ) of the first throttle ( 5 ) having. Pump comprising a mechanical seal ( 1 ) according to any one of the preceding claims.

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