Abstract
Throttle ring for a piston compressor, the throttle ring comprising an axially running ring axis (Ar), an axial height (h), a radially inner running surface and a radially outer circumferential surface, and an upper flank and a lower flank, wherein the upper flank faces the compression space of the piston compressor when the throttle ring is in intended use. The running surface has at least one circumferential groove in the circulating direction, which is connected to the radially outer circumferential surface by at least one radial bore.
Claims
1-15. (canceled)
16. A throttle ring for a piston compressor, said throttle ring having an axially running ring axis, an axial height, a radially inner running surface and a radially outer circumferential surface, and an upper flank and a lower flank, the upper flank facing a compression space of the piston compressor when the throttle ring is used as intended, the running surface having at least one groove which runs around in a circulating direction and is connected to the radially outer circumferential surface by at least one radial bore.
17. The throttle ring according to claim 16, wherein the throttle ring is formed as an endless ring.
18. The throttle ring according to claim 16, wherein the throttle ring has at least one channel extending in a radial direction.
19. The throttle ring according to claim 16, wherein the radial bores have a diameter in the range between 0.5 mm and 3 mm.
20. The throttle ring according to claim 16, wherein the radial bores extending from the respective groove to the circumferential surface are arranged axially symmetrically to one another with respect to the ring axis.
21. The throttle ring according to claim 16, wherein the grooves extend substantially parallel to the upper flank and lower flank of the throttle ring.
22. The throttle ring according to claim 16, wherein the grooves are arranged in a range of 10% to 90% relative to the axial height of the throttle ring.
23. The throttle ring according to claim 16, wherein the grooves each have a groove depth between 0.5 mm and 3 mm or a groove width between 0.5 mm and 3 mm, or a combination thereof.
24. The throttle ring according to claim 16, wherein the grooves have different groove widths.
25. The throttle ring according to claim 24, wherein the groove width decreases in the direction of the upper flank or increases from both flanks in the direction of half the axial height.
26. The throttle ring according to claim 16, wherein the throttle ring consists of plastic.
27. The throttle ring according to claim 16, wherein the running surface is provided with a wear protection layer at least in a region of the surface which can be brought into contact with a piston rod of the piston compressor.
28. A piston rod seal arrangement for sealing a longitudinally movably mounted oscillating piston rod of a piston compressor, the piston rod seal arrangement comprising at least one throttle ring according to claim 16 and at least one sealing element mounted downstream of the throttle ring.
29. A dry-running piston compressor comprising a piston rod seal assembly according to claim 28.
30. A method of compressing boil-off gas produced during the storage of liquefied natural gas, the method comprising the steps of: providing at least one dry-running piston compressor according to claim 29; single- or multi-stage compression of the boil-off gas; at least partially supplying a multi-fuel engine with the compressed boil-off gas as fuel, or at least partially reliquefying the boil-off gas, or a combination of both processes; wherein the pressure increase achieved by the single-stage or multi-stage compression is at least 200 bar.
Description
[0060] It shows:
[0061] FIG. 1 a throttle ring according to the invention;
[0062] FIG. 2a a top view of a first embodiment of a throttle ring;
[0063] FIG. 2b a cut through FIG. 2a along line A-A;
[0064] FIG. 2c a cut through FIG. 2a along line B-B;
[0065] FIG. 3a a top view of a packing cartridge;
[0066] FIG. 3b a cut through FIG. 3a along line C-C;
[0067] FIG. 3c a cut through FIG. 3a along line D-D.
[0068] FIG. 1 shows a perspective view of a throttle ring 1 for a pis-ton compressor. The throttle ring 1 has a ring axis Ar running in the axial direction and has a recess with a radially inner running surface 2 in the axial direction, along which a piston rod 14 (shown approximately in FIG. 3b) can be moved. The diameter of the axial recess is dimensioned in such a way that the throttle ring 1 can completely enclose the piston rod while not or barely touching the surface of the moving piston rod. For example, the axial play of the throttle ring 1 is between 0.1 and 0.25 mm. This ensures that no or only a small amount of frictional heat is generated when the throttle ring 1 is used as intended. In the example shown, the running surface 2 has three mutually spaced grooves 6 in the direction of the ring axis Ar, which run in the circulating direction and are of endless de-sign. In the example shown, the middle of the three grooves 6 is connected to the radially outer circumferential surface 3 by six radial bores 7, as shown in even greater detail in the cross-section shown in FIG. 2c. The throttle ring 1 further has an upper flank 4 and a lower flank 5 arranged opposite thereto. In the example shown, the upper flank 4 has six channels 8 extending in the radial direction and having a rectangular cross-section. Of course, it is also conceivable that the radial channels 8 have a different cross-sectional shape.
[0069] FIG. 2a shows the throttle ring 1 of FIG. 1 in a top view onto the upper flank 4. The radially inner running surface 2 and the radially outer circumferential surface 3 run concentrically to each other. In the present embodiment, the radial bores 7 and also the radial channels 8 are arranged axially symmetrically to one another with respect to the ring axis Ar, and are mutually evenly spaced in the circumferential direction. In the circumferential direction, for example, one, two, four, six or eight radial bores 7 could be arranged mutually spaced, preferably mutually equally spaced.
[0070] FIG. 2b shows a radial cut through the embodiment shown in FIG. 2a along line A-A. The annular body of the throttle ring 1 can be rectangular in shape, as in the present embodiment. The three circumferential grooves 6 extend substantially parallel to the two flanks 4 and 5 of the throttle ring 1. In the present embodiment, the three circumferential grooves 6 have substantially equal groove widths and groove depths. Of course, it would also be possible for the circumferential grooves 6 to have different groove widths and/or groove depths from one another. It would also be possible, for example, for two or all of the circumferential grooves 6 to have one or more radial bores 7 via which the respective grooves 6 are in fluid connection with the radially outer circumferential surface 3.
[0071] FIG. 2c shows a cut along the line B-B according to FIG. 2a. The annular body of the throttle ring 1 has a height h in the axial direction Ar. A radial bore 7 is shown, which opens from the radially outer circumferential surface 3 into the middle of the three circumferential grooves 6 and connects the radially inner running surface 2 with the radially outer circumferential surface 3. The middle of the three circumferential grooves 6 is arranged at half the axial height h/2 of the throttle ring 1. The webs 9 arranged in each case between two circumferential grooves represent throttling points in conjunction with a piston rod running back and forth in the axial recess of the throttle ring 1 (shown in FIG. 3b).
[0072] FIG. 3a shows a top view of a piston rod seal arrangement 10 with two cooling channels 16, a supply channel and a discharge channel for the coolant. In the present embodiment, the piston rod seal arrangement 10 comprises two sealing elements 13 and a throttle ring 1, as will be explained in more detail in the fol-lowing drawings.
[0073] FIG. 3b shows an axial cut through the piston rod sealing arrangement 10 according to the line C-C in FIG. 3a, wherein in the installed state the piston rod drive is located on side 12 and the compression chamber is located on side 11. The packing is designed as a dry-running sealing arrangement and in the present embodiment comprises two chamber rings 17 arranged one af-ter another in the direction of the piston rod 14 with sealing elements 13 arranged therein. The throttle ring 1 is arranged on the compression chamber side adjacent to the sealing elements 13.
[0074] FIG. 3c shows an axial cut through the piston rod seal arrangement 10 according to the line D-D in FIG. 3a, which passes through the lubrication channel 15 as well as one of the cooling channels 16.
[0075] In an advantageous embodiment, the throttle ring 1 described above is configured such that each of the circumferential grooves 6 on the radially inner running surface 2 is connected to the radially outer circumferential surface 3 by at least one radial bore 7, and preferably two, four, six or eight bores 7. In an advantageous embodiment, the throttle ring described above is designed in such a way that the radially inner running surface 2 of the throttle ring is made of a material with greater hardness than that of the flanks.
[0076] In an advantageous embodiment, the throttle ring described above is designed in such a way that the circumferential grooves 6 are spaced apart from one another in the direction of the ring axis Ar by a distance of 0.5 mm to 5 mm, preferably lmm to 3 mm.
