FORELINE FOR A VACUUM PUMP

Abstract

A foreline for a vacuum pump with an inlet connectable to e.g. a vessel to be evacuated and an outlet connected to and inlet of the vacuum pump to evacuate the vessel. Thereby, the foreline further comprises a discharge line with a first end and a second end, wherein the first end comprises an opening and the second end comprises a solid material trap. The second end is arranged outside the foreline. The first end is arranged within the foreline between the inlet and the outlet and the opening is open towards the inlet of the foreline such that incoming solid material is collected by the opening, discharged through the discharge line and caught in the solid material trap.

Claims

1. A foreline for a vacuum pump with an inlet connectable to a vessel to be evacuated and an outlet connectable to an inlet of the vacuum pump to evacuate the vessel, wherein the foreline further comprising: a discharge line with a first end and a second end, wherein the first end comprises an opening and the second end comprises a solid material trap, wherein the second end is arranged outside the foreline, wherein the first end is arranged within the foreline between inlet and outlet and the opening is open towards the inlet of the foreline such that incoming solid material is collected by the opening, discharged through the discharge line and caught in the solid material trap.

2. The foreline in accordance with claim 1, characterized in that the inlet and the opening of the discharge line are arranged on a substantially vertical axis.

3. The foreline in accordance with claim 1, characterized in that the foreline is straight and in particular inlet and outlet of the foreline are arranged on a substantially vertical axis.

4. The foreline in accordance with claim 1, characterized in that the foreline has a first section having a first diameter and a second section having a second diameter, wherein the first diameter is smaller than the second diameter.

5. The foreline in accordance with claim 4, characterized in that the opening of the discharge line is arranged in the second section, wherein the opening has a diameter larger than or equal to the first diameter and smaller than the second diameter.

6. The foreline in accordance with claim 1, characterized in that the opening is provided by a funnel, preferably a perforated funnel.

7. The foreline in accordance with claim 1, characterized in that the trap is releasably attached to the discharge line.

8. The foreline in accordance with claim 1, characterized in that a valve is disposed in the discharge line.

9. The foreline in accordance with claim 1, characterized in that the trap comprises a gauge to detect the amount of solid material in the trap.

10. The foreline in accordance with claim 1, characterized in that the trap comprises a scale mechanism to detect the amount of solid material in the trap.

11. The foreline in accordance with claim 1, characterized in that the trap comprises an inlet port to add substances into the trap, such that the captured solid material is pre-treated before removing, in particular to render inert the solid material.

12. The foreline in accordance with claim 1, characterized in that the trap comprises a port adapted to be connected to a suction device preferably a vacuum cleaner.

13. The foreline in accordance with claim 1, characterized in that the inlet is defined by a first element and the outlet and discharge line is defined by a second element, wherein the first element is moveable with respect to the second element along the straight line, thus making the distance between a rim of the opening and a sidewall of the foreline adjustable.

14. The foreline in accordance with claim 13, characterized in that the first element comprises at least one, preferably two tabs and the second element provides at least one, preferably two tabs which are aligned with the tabs of the first element, wherein at least one, preferably two distance elements are disposed between the tabs to adjust the position of the first element relative to the second element.

15. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the following the invention is described as respect to specific embodiments with reference to the accompanied drawings.

It is shown:

[0032] FIG. 1 a schematic side view of the foreline in accordance with the present invention,

[0033] FIG. 2 a sectional view of the foreline shown in FIG. 1,

[0034] FIG. 3 another embodiment in a sectional view in accordance with the present invention and

[0035] FIG. 4 another embodiment of the foreline in accordance with the present invention.

DETAILED DESCRIPTION

[0036] A foreline for a vacuum pump in accordance with the present invention comprises an inlet 10 adapted to be connectable to for example a vessel to be evacuated. Alternatively, the inlet 10 can be connected to another vacuum line or any vacuum apparatus of any kind. Therefore, the inlet 10 may comprise a vacuum flange to be connected to its counterpart. The foreline further comprises an outlet 12 which might also comprise a flange wherein the outlet 12 is adapted to be connected to a vacuum pump. By the vacuum pump a gaseous medium is conveyed from the inlet 10 of the foreline towards the outlet 12 of the foreline in order to establish or maintain a vacuum at the inlet 10 of the foreline.

[0037] In accordance to the present invention, the inlet 10 and the outlet 12 are arranged on a vertical axis 14. In particular, the complete foreline is straight without any bending in order to improve the conductance of the foreline enhancing the performance of the attached vacuum pump.

[0038] The foreline, as shown in FIG. 1, comprises a first section 16 having first diameter D.sub.1, a second section 18 having a second diameter D.sub.2 and a third section 20 having a third diameter D.sub.3, wherein the first diameter D.sub.1 is identical or almost identical to the third diameter D.sub.3, while the second diameter D.sub.2 is larger than the first diameter D.sub.1 and in particular also larger than the third diameter D.sub.3. Thus, by the second section 18 a buffing element 22 is built in order to buffer fluctuations in the vacuum pressure and ensure continuous operation of the vacuum pump.

[0039] During operation, when the foreline in accordance to the present invention is attached to a vacuum pump, the vertical axis 14 corresponds to a vertical orientation, thus the inlet 10 is arranged above the outlet 12.

[0040] Further the foreline comprises a discharge line 24, having a first end 26 and a second end 28. Thereby, the first end 26 is arranged within the foreline and preferably within the second section 18. The second end 28 is arranged outside the foreline. The first end 26 comprises and opening 30 which is arranged directly beneath the inlet 10 of the foreline on a common vertical axis 14 and is open towards the inlet 10. The second end 28 of the discharge line 24 comprises a trap 32 which is releasably attached to the discharge line 24, for example by respective flanges 34. Any solid material transported by the gaseous medium or process gas which enters the foreline through the inlet 10, is collected by the opening 30 and then discharged through the discharge line 24 and finally collected in the trap 32. Thereby, the gaseous medium can pass by the opening 30 in accordance to the arrows 36 and is able to flow towards the outlet 12 of the foreline towards the vacuum pump.

[0041] As a consequence, by the straight construction of the foreline, a high conductance of the foreline is provided since the process gas needs not to follow any branches to reach the vacuum pump. Thus, the pump performance is improved. Additionally, solid material or dust entering the foreline through the inlet are collected by the opening 30 and finally collected and stored in the trap 32. Since the trap 32 is releasably attached to the discharge line 24, the trap can be easily detached and emptied during service times.

[0042] In accordance to the embodiment shown in FIG. 2, the opening 30 is built by a funnel 38, wherein the funnel is preferably perforated in order to enhance the conductance of the foreline further. Thereby, the outer rim of the funnel 38 defines the opening 30, wherein the opening 30 has a diameter D.sub.d. Thereby, the diameter D.sub.d of the opening 30 is larger than the diameter D1 of the first section 16 and smaller than the diameter D2 of the second section 18. Thus, it is D1<D.sub.d<D2. Thereby, it is ensured that all solid material or dust is collected by the opening 30 and only the gaseous medium can pass by the opening 30 and flow towards the vacuum pump. As a consequence, no dust or solid material reaches the vacuum pump and contaminates or damage of the vacuum pump is avoided.

[0043] In the following Figures same or similar elements are indicated with identical reference numbers.

[0044] In the embodiment of FIG. 3 the foreline comprises a first element 40 defining the inlet 10 and the first section 16. Further, the foreline comprises a second element 42 defining the discharge line 24 with the opening 30 and the second section 18 as well as the third section 20. Thereby, the first element 40 is relatively movable with respect to the second element 42, as indicated by the arrow 44. By adjusting the position of the first element with respect to the second element 42 along a vertical line in accordance with the arrow 44, the clearance between the sidewall 46 of the foreline and the rim 48 of the funnel 38 is adjusted. Thereby, the conductance of the foreline can be balanced with the necessity to capture more or less all solid material by the discharge line 24. If the clearance between the discharge line 24, in particular the rim 48 of the funnel 38, and the sidewall 46 is reduced, the possibility is enhanced that dust or solid material entering through the inlet 10 of the foreline is captured by the discharge line 24, i.e. the opening 30. However, simultaneously the conductance of the foreline is reduced. If the clearance between the rim 48 and the sidewall 46 is enlarged, the conductance of the foreline is improved while also increasing the possibility that dust or solid material is not collected by the opening 30 and may bypass the discharge line 24. Thus, the foreline can be adapted to the specific needs of different applications. As a consequence, only one type of foreline is necessary for a large number of different applications and also different vacuum pump types, since the clearance can also be adapted to the volume flow rate or throughput of the used vacuum pump.

[0045] In order to adjust the position of the first element 40 in relative to the position of the second element 42, the first element 40 comprises at least one tab 50 and preferably more than one tab 50. Also the second element 42 comprises an equal number of tabs 52, wherein the positions of the tabs 50 of the first element 40 are aligned with the respective positions of the tabs 52 of the second element 42. Thereby, a distance element 54 is disposed between the respective tabs 50, 52 in order to adjust and maintain the position of the first element 40 relative to the second element 42. The distance element might be a spacer or a screw, wherein at least one tab 50, 52 may comprises a thread in order to adjust the position of the first element 40 relative to the position of the second element 42 by turning the screw.

[0046] In accordance to the embodiment shown in FIG. 4, the discharge line 24 comprises a gate valve 56. By closing the gate valve 56 the trap 32 can be detached from the discharge line 24 and collected dust or solid material can be removed from the trap 32 during technical service. Thus, it is possible to maintain the vacuum in the foreline during removing of the trap 32. Thus, technical service times are greatly reduced. Interruption of the operation of the vacuum system for emptying the trap 32 is not necessary due to the gate valve 56.

[0047] Further, the trap 32 provides a detection port for a gauge 58 in order to detect the amount of collected solid material or dust. Thus, the trap 32 is only emptied if necessary when the gauge detects a certain amount of collected dust or solid material.

[0048] Further the trap 32 may comprise a scale mechanism in order to rate the amount of collected dust or solid material. Thus, technical service can be planned in accordance to the collected solid material.

[0049] The present invention provides a foreline for a vacuum pump which ensures a high conductance due to the straight design of the foreline while it is ensured that almost all dust or solid material entering the foreline through the inlet is collected by the discharge line and collected or stored in the trap. Thereby, the foreline is easily maintainable due to the releasably attached trap. Further by employing a gate valve in the discharge line, maintenance can be performed during the operation of the vacuum system.

[0050] Although elements have been shown or described as separate embodiments above, portions of each embodiment may be combined with all or part of other embodiments described above.

[0051] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are described as example forms of implementing the claims.