PRESSURE ACCUMULATOR HAVING A MONITORING DEVICE

Abstract

A pressure accumulator having an accumulator housing (10) in which a movable separating element (16) separates a gas room (12) filled with a working gas from a fluid room (14) in a fluid-sealed manner, wherein a monitoring device (46) is provided, which, in the event of a fault impairing the sealing effect of the separating element (16), provides an optically discernible indication and which has an inspection window (54), through which an indicator can be observed, which is connected to the gas room (12) and whose optical properties change discernibly when wetted with the fluid, is characterized in that the indicator changing its optical properties is accommodated in a capsule (48), the capsule wall (50) of which is permeable to the passage of the fluid and which is arranged between the inspection window (54) and the separating element (16) in the accumulator housing (10).

Claims

1. A pressure accumulator having an accumulator housing (10) in which a movable separating element (16) separates a gas room (12) filled with a working gas from a fluid room (14) in a fluid-sealed manner, wherein a monitoring device (46) is provided, which, in the event of a fault impairing the sealing effect of the separating element (16), provides an optically discernible indication and which has an inspection window (54), through which an indicator can be observed, which is connected to the gas room (12) and whose optical properties change discernibly when wetted with the fluid, characterized in that the indicator changing its optical properties is accommodated in a capsule (48), the capsule wall (50) of which is permeable to the passage of the fluid and which is arranged between the inspection window (54) and the separating element (16) in the accumulator housing (10).

2. The pressure accumulator according to claim 1, characterized in that the capsule (48) has a pad (60) in its interior, which accommodates the indicator and which is accommodated between at least one fluid-permeable protective layer (72, 74).

3. The pressure accumulator according to claim 1, characterized in that the capsule (48) has a circumferential trough rim (76) protruding in the direction of the inspection window (54), for the purpose of holding an indicator dissolved and/or dispersed in the fluid, which emerges from passages (82) in the upper capsule shell (68) of the capsule (48), and that passages (80) in the lower capsule shell (66) permit the fluid to pass into the capsule (48) having the pad (60).

4. The pressure accumulator according to claim 1, characterized in that the trough rim (76) of the capsule (48) is formed by a lateral rim of the lower capsule shell (66), which projects axially beyond the upper capsule shell (68) to form a receptacle trough (62).

5. The pressure accumulator according to claim 1, characterized in that the receptacle trough (62) is spanned by a lid part (64) which, when kept transparent, permits a view from the inspection window (54) at least of the content of the trough.

6. The pressure accumulator according to claim 1, characterized in that the lid part (64) is provided with optical properties, such as prismatic properties, a coating or a magnification.

7. The pressure accumulator according to claim 1, characterized in that the inspection window (54) is formed of a gauge glass, which is inserted into a cover-side closure part (18) of the accumulator housing (10) and permits a view of the capsule (48) from outside.

8. The pressure accumulator according to claim 1, characterized in that the lid part (64) and the capsule (48) having the indicator pad (60) are held by a screen body (56), which can be inserted into the cover-like end part (18) of the accumulator housing (10) from the side of the separating element (16) and in particular is held in position by means of a screw insert (58).

9. The pressure accumulator according to claim 1, characterized in that the indicator, when in contact with the fluid, starting from a neutral color, causes a visible color change under formation of a signal color, and the indicator is selected from the group of substances of the (diethylamino)benzo[a]phenoxazines.

10. The pressure accumulator according to claim 1, characterized in that the pad (60) for the indicator is a fleece, preferably a glass fiber fleece, or a glass fiber fabric, in particular a glass silk fabric.

11. A monitoring device (46) for detecting an undesired fluid and for optically indicating the occurrence of this fluid as a fault, having an indicator, which can be wetted with the fluid and the optical properties of which discernibly change when wetted with the fluid, and having an inspection window (54), through which the indicator can be observed, characterized in that the indicator changing its optical properties is accommodated in a capsule (48), the capsule wall (50) of which is permeable to the passage of the fluid and which is arranged in a position permitting the observation through the inspection window (54).

12. A capsule for a monitoring device (46) according to claim 11, in particular for use in a pressure accumulator, characterized in that it (48) has a pad (60) in its interior, which accommodates the indicator, and in that the capsule wall (50) is permeable to the passage of a fluid to be detected.

Description

[0021] FIG. 1 shows a sectional view of a pressure accumulator having an accumulator housing 10 having a gas room 12 filled with a working gas and a fluid room 14, which are separated from each other in a fluid-sealed manner by a movable separating element 16. The accumulator housing 10 of the pressure accumulator, which is rotationally symmetrical to an axis of rotation R, comprises a cover-sided closing part 18 and a tubular cylindrical main part 20 having a bottom 21. The closing part 18 and the main part 20 are welded together on a circumferential, narrow mounting surface 22. The gas room 12 is located in the part, assigned to the closing part 18, of the accumulator housing 10. An annular insert part 24 having a horizontal first section 26 and a vertical second section 28 directed towards the fluid room14 is provided in the area of the connection of the closing part 18 to the main part 20.

[0022] The rotation axis R of the pressure accumulator determines the vertical direction. The first section 26 forms an upper attachment point for the separating element 16, which is formed as a bellows. The lower end of the separating element 16 is attached to a plate part 30, which is movably arranged inside the pressure accumulator and has a circular cross-section corresponding to the inner cross-section of the accumulator housing 10. In the unused state of the accumulator shown in FIG. 1, the maximum extension of the separator element 16 is in the axial direction and the plate part 30 is located close to the bottom 21 of the accumulator housing 10. In a rim section 32 of the plate part 30 the latter has a slightly greater thickness as the main part in the center. At the rim section 32 several guides 34 are formed, which are directed towards the inner wall of the accumulator housing 10 and facilitate an axial movement of the plate section 30 in the pressure accumulator without obstacles.

[0023] To the bottom 21 of the accumulator housing 10 an extension-like connecting element 36 adjoins, in which a fluid port 38 is formed, which opens into the fluid room14. To close the fluid port 38 using a screw cap, not shown in FIG. 1, an outer thread 40 is formed at the lower end of the connecting element 36, wherein said outer thread 40 is otherwise used to connect a fluid line (not shown), to which the bellows accumulator can be connected. In the cover side closing part 18 of the accumulator housing 10 a filling port 44 for filling the gas room12 is formed offset to the axis of rotation R and closed in a gas-sealed manner by a fitting 42.

[0024] The central component of the pressure accumulator is a monitoring device 46, which is inserted into an extension of the cover-sided closing part 18 protruding into the interior of the accumulator housing 10, in a manner that is rotationally symmetrical to the axis of symmetry R. The monitoring device 46 provides an optically recognizable indication in the event of a malfunction impairing the sealing effect of the separating element 16, wherein in the event of the malfunction fluid passes from the fluid room14 into the gas room 12. For this purpose, the monitoring device 46 has an indicator accommodated in a capsule 48, wherein said indicator recognizably changes its optical properties when wetted with the fluid undesirable in the gas room 12. A capsule wall 50 is formed to be permeable for the passage of the fluid.

[0025] To observe the indicator and a change of its optical properties, an inspection window 54 is arranged at the outside end of the monitoring device 46, which is arranged in a through bore 52 in the closing part 18. The inspection window 54 is preferably formed by a shatterproof gauge glass and provides a view of the capsule 48 from the outside. For position fixation of the capsule 48, a screen body 56 is arranged at the inner end of the monitoring device 46, assigned to the separating element 16, wherein said screen body 56 is inserted from the side of the separating element 16 into the cover-like closing part 18 and held there in position by means of a screw insert 58.The capsule 48 having the indicator changing its optical properties is arranged between the inspection window 54 and the separating element 16 in the accumulator housing 10 and is held in its position by the screen body 56.

[0026] FIG. 2 shows an enlarged view, corresponding to the circular section K, of the monitoring device 46 of FIG. 1 having the inspection window 54, the capsule 48 and the screen body 56 including the screw insert 58. FIG. 2 illustrates that the capsule 48 accommodates a flat pad 60 (cushion) in its inside, which in turn accommodates the indicator and is a fleece, preferably a glass fiber fleece, or a glass fabric, in particular a glass silk fabric. The indicator is a reagent accommodated in the pad 60, wherein said reagent changes its optical properties on contact with the fluid, preferably starting from a neutral color to a visible color change, under creation of a signal color. Preferably, the indicator is selected from the group of substance of (diethylamino)benzo[a]phenoxazines, which causes the color to change to the signal color red. To permit a contact of the pad 60 and a reaction of the indicator with the fluid to be detected, the capsule wall 50 is provided with passages 80, 82 (see FIG. 3) for the passage of the fluid.

[0027] A receptacle trough 62 for the fluid emerging at the top of the pad 60 is formed above the capsule 48. The receptacle trough 62 is spanned by an upwardly curved lid part 64, which, when kept transparent, permits a view from the inspection window 54 at least of the contents of the trough. The lid part 64 has optical properties, such as prismatic properties, a coating or a magnification. This permits in a simple and reliable way an observation of an optically changed, preferably discolored fluid at the top of the capsule 58, which indicates a failure due to a defect at the separator element 16. The color change towards a signal color can be clearly observed through the inspection window 54, even in daylight. The monitoring device 46 permits a non-destructive, tool-free visual inspection of the separator element 16 located in the accumulator housing 10 during operation and maintenance. In particular, the trough formation of the capsule 48 in its upper area significantly increases the indicator area, which results in improved discernibility of the color change compared to known solutions.

[0028] FIG. 3 shows the formation of the capsule 48 in detail, in particular as part of the monitoring device 46 according to the invention, which is held stationary by the screen body 56, for instance in the through hole 52 of an closing part 18 or a different component. The capsule 48 has a lower capsule shell 66 and an upper capsule shell 68, which are arranged in parallel to each other in the central main part of the capsule 48, enclose the pad 60 and are in contact with each other in the rim area 70. In the rim area 70, the two capsule shells 66, 68 fix between them a lower fluid permeable protective layer 72 and an upper fluid permeable protective layer 74. The pad 60 is located between the two fluid-permeable protective layers 72, 74. The lower capsule shell 66 is widened compared to the upper capsule shell 68 and its lateral rim is bent upwards. In this way the lower capsule shell 66 protrudes over the upper capsule shell 68, forming the receptacle trough 62. The lateral rim of the lower capsule shell 68 forms a trough rim 76, which is used as a support for the lid part 64 to span the receptacle trough 62. The inspection window 54 adjoins to the lid part 64, leaving a narrow gap 78 between the lid part 64 and the inspection window 54. It is also conceivable to arrange the inspection window 54 such that it lies flat against the lid part 64, thereby omitting the gap 78. It is also conceivable to integrate the optical properties provided by the lid part 64 into the inspection window 54, for instance by providing a coating on the lower side assigned to the capsule 48 and placing the inspection window 54 directly on the trough rim 76.

[0029] A number of passages 80 and 82 is formed in the two capsule shells 66, 68, which each permit the fluid to pass through with or without indicator. In the event of a fault, the fluid coming from a gas room 12 (see FIG. 1), for instance, reaches the capsule 48 through the screen body 56. The fluid reaches the pad 60 having the indicator contained therein through the passages 80 in the lower capsule shell 66 and the lower fluid-permeable protective layer 72. Because of a reaction with the indicator, the fluid changes its optical properties and advantageously adopts a signal color, such as red. Starting from the pad 60, upon further spread the fluid reaches the receptacle trough 62 through the upper fluid-permeable protective layer 74 and the other passages 82 in the upper capsule shell 68. The discolored fluid as the content of the trough is clearly discernible to an observer through the transparent inspection window 54 and the transparent lid part 64 as a signal for a fault.

[0030] The solution according to the invention is not limited to the use of bellows accumulators, but can be used for all types of pressure accumulators, such as piston, bladder and diaphragm accumulators for instance, in which a movable separating element separates a gas working room from a fluid room.