WO2015104161A1

WO2015104161A1 - Helium vessel port arrangement for a magnetic resonance imaging system

Info

Publication number: WO2015104161A1
Application number: PCT/EP2014/078577
Authority: WO
Inventors: Patrick William Retz; Neil Charles Tigwell
Original assignee: Siemens PLC
Current assignee: Siemens PLC
Priority date: 2014-01-07
Filing date: 2014-12-18
Publication date: 2015-07-16
Anticipated expiration: 2016-07-07
Also published as: CN106415166A; GB2524598A; GB201400201D0; US20160334060A1; US9593807B2; CN106415166B; GB2524598B; GB201410505D0

Abstract

A cryogen vessel port arrangement for a magnetic resonance imaging (MRI) system comprising a port (30) for guiding cryogen into a cryogen vessel is described. The port (30) comprises a siphon tube (32), a siphon cone (33), which is in flow connection with the siphon tube (32), and a pipe (34) with an inlet opening (35) and an outlet opening (36). The inlet opening (35) is configured for connecting it with a coldhead sock and the outlet opening (36) is in flow connection with the port (30) and the siphon cone (33). The port (30) comprises a port component (40) which comprises a flow channel (44) with a first opening (41) configured for connecting it with a service siphon (53, 63), a second opening (42) which is in flow connection with the siphon cone (33), and a third opening (43) which is in flow connection with the outlet opening (36) of the pipe (34).

Description

Helium vessel port arrangement for a magnetic resonance imag^¬ ing system

Field of the invention

The present invention relates to a helium vessel port ar^¬ rangement and a helium vessel arrangement for magnetic reso- nance imaging (MRI) systems, especially for superconducting magnet systems with a helium cooling system. It further relates to a method for operating the helium vessel port ar^¬ rangement . Background of the invention

Magnetic resonance imaging (MRI) systems typically comprise superconducting magnets and a helium cooling system. In the helium cooling system the gaseous helium is recondensed by means of a coldhead and guided into a helium vessel.

To exchange the coldhead the magnet has to be ramped down be^¬ cause the coldhead sock is connected to the helium vessel by a pipe. Failure to do this could, in the event of a quench result in a dangerous amount of helium gas escaping into the region of the Service Engineer carrying out the cold head ex^¬ change .

Furthermore, during coldhead exchange there is a risk of air ingress and subsequent ice build-up in the coldhead sock and connecting pipe. During the life of the magnet ice can col^¬ lect in the pipe connecting the coldhead sock to the turret which is difficult to remove. The removal of the coldhead is necessary to carry out the de-ice operation which also re- quires the magnet to be ramped down. Currently in order to exchange a coldhead it has been necessary to ramp the magnet down. Also in order to de-ice the connecting pipe it has been necessary to ramp the magnet down and remove the coldhead.

Description of the invention

It is therefore an objective of the present invention to pro^¬ vide an advantageous helium vessel port arrangement for mag^¬ netic resonance imaging systems, a magnetic resonance imaging system and a method to operate this arrangement, which espe- cially allows an exchange of a coldhead without ramping down the magnet.

This objective is solved by a helium vessel port arrangement as claimed in claim 1, a helium vessel arrangement as claimed in claim 10, a magnetic resonance imaging system as claimed in claim 15 and by a method to operate the helium vessel port arrangement as claimed in claim 11. The depending claims de^¬ fine further developments of the present invention. The inventive helium vessel port arrangement for a magnetic resonance imaging (MRI) system comprises a port for guiding helium into a helium vessel. Part of the helium vessel port comprises a siphon tube, a siphon cone and a pipe or flow channel. The siphon cone is in flow connection with the si- phon tube. The pipe or flow channel comprises an inlet open^¬ ing and an outlet opening. The inlet opening is configured for connecting it with a coldhead sock, more precisely for providing a flow connection with the cold head sock. The outlet opening is in flow connection with the port and the si- phon cone. The port comprises a port component. The port com^¬ ponent comprises a flow channel with a first opening config^¬ ured for connecting the flow channel with a service siphon, a second opening which is in flow connection with the siphon cone, and a third opening which is in flow connection with the outlet opening of the pipe connected to the coldhead sock . The above described difficulties have been solved by extend^¬ ing the coldhead connection pipe into the helium vessel or into a turret by means of the port component that can inter^¬ face with a standard service siphon fitted with different tips.

An advantage of this arrangement is that the first opening of the port component may be configured for aligning a service siphon, for example a standard helium service siphon, in the siphon cone.

An option of this arrangement is that the inventive helium vessel port comprises a support component configured for maintaining alignment of a service siphon and/or for main- taining alignment of the port component with respect to the siphon cone and/or with respect to the outlet opening of the pipe .

The port arrangement can comprise a turret. The helium vessel port arrangement or the turret can comprise a wall. The pipe can be positioned in the wall. For instance, the pipe can be partly or completely positioned within the wall. The pipe is preferably welded into the wall. The first opening of the port component may comprise a cen^¬ treline and the second opening of the port component may com^¬ prise a centreline. The siphon cone may comprise a centre^¬ line, which corresponds with the centreline of the first opening and/or the second opening and/or a centreline of a service siphon. In other words, the centreline of the siphon cone may be an elongation of the centreline of the first opening and/or the second opening and/or a centreline of a service siphon or the centreline of the siphon cone may be identical with the centreline of the first opening and/or the second opening and/or a centreline of a service siphon. This has the advantage, that the service siphon can easily be in^¬ serted and fitted into the siphon cone. The helium vessel port arrangement may comprise a vessel ex^¬ amination tube, which is configured for inserting a service siphon into the port component. The vessel examination tube may comprise an outer tube and an inner tube and may be con^¬ figured for inserting the service siphon into the port compo^¬ nent via the outer tube.

The helium vessel port arrangement preferably comprises a service siphon with a tip comprising an opening, wherein the tip is fitted into the port component and configured such that the third opening of the port component and/or the out^¬ let opening of the pipe are/is closed by means of the tip and the opening of the tip is in flow connection with the siphon cone. This configuration provides the possibility to provide a helium vessel with helium from the service siphon while the coldhead can be exchanged or de-ice operation can be carried out without ramping down the magnet. In a further variant the helium vessel port arrangement can comprise a service siphon with a tip. The tip may have or comprise an opening. The tip may be fitted into the port com^¬ ponent and configured such that the siphon cone is closed by means of the tip and the opening of the tip is in flow con- nection with the third opening of the port component and/or with the outlet opening of the pipe. Preferably, the opening of the tip is only in flow connection with the third opening of the port component and/or with the outlet opening of the pipe. This configuration provides the possibility to provide the pipe and for example a coldhead sock with helium gas from the service siphon. By means of the described tip the cold- head sock can be isolated from a helium vessel or from a turret. The configuration can be used to de-ice a connecting tube. Moreover, the configuration can also provide positive flow of helium gas to prevent air ingress during coldhead ex^¬ change. The tip can remain in place until the coldhead has cooled down. The coldhead could be force cooled by using cold helium through the service siphon and venting via a transit line and a valve, for example a bypass valve.

Generally, the service siphon is preferably a helium siphon. The helium vessel port arrangement can comprise a turret, which may comprise the port component.

The inventive helium vessel arrangement comprises a previ^¬ ously described helium vessel port arrangement. It may com- prise a helium vessel and a previously described helium ves^¬ sel port arrangement. The helium vessel arrangement has the same advantages as the previously described helium vessel port arrangement. The inventive magnetic resonance imaging system comprises a previously described inventive helium vessel port arrangement and/or a previously described inventive helium vessel ar^¬ rangement. The inventive magnetic resonance imaging system has the same advantages as the inventive helium vessel port arrangement.

The inventive method for operating an inventive helium vessel port arrangement, as previously described, is characterised in guiding helium, preferably liquid helium, into the inlet of the pipe, through the pipe and via the outlet of the pipe into the port for guiding helium into a helium vessel. The helium can be guided from a coldhead sock into the inlet of the pipe. The inventive method has the same advantages as the previously described inventive helium vessel arrangement.

An advantage of this arrangement is that helium is guided into the inlet of the pipe, through the pipe and via the out^¬ let of the pipe into the siphon cone and into the siphon tube .

An option of this arrangement is that the method comprises the step of closing the third opening of the port component and/or closing the outlet opening of the pipe, and guiding helium from the service siphon into the siphon cone and into the siphon tube. This allows filling of a helium vessel with helium from the service siphon while the coldhead can be ex- changed or de-ice operation can be carried out without ramp^¬ ing down the magnet.

As a further option the method comprises the step of closing the siphon cone by means of the tip of the service siphon and guiding helium from the service siphon into the third opening of the port component and/or into the outlet opening of the pipe. By means of the described tip the coldhead sock can be isolated from a helium vessel and/or from a turret. The con^¬ figuration can be used to de-ice a connecting tube. Moreover, the configuration can also provide positive flow of helium gas to prevent air ingress during coldhead exchange. The tip can remain in place until the coldhead has cooled down. The coldhead could be force cooled by using cold helium through the service siphon and venting via a transit line and a valve, for example a bypass valve.

Generally, an advantage of the present invention lies in the addition of an interface or port component at the end of the coldhead connection pipe situated in line with a siphon port, for example at the lower end of a turret. The design of the interface or port component allows the siphon to operate in the usual way. In addition the following operations are now possible. It is possible to isolate the coldhead sock from the helium vessel. This enables cold head exchange at field without risk of asphyxiation. Moreover, there is the ability to de-ice the cold head connection tube without removing the cold head, potentially with the magnet still at field. Fur^¬ thermore, there is the ability to create a controlled flow of helium gas through the pipe and a connection tube and out through the coldhead sock to prevent air ingress during cold- head exchange. Additionally, there is the ability to keep the coldhead sock isolated from the helium vessel whilst the coldhead cools down to prevent warm gas entering the helium vessel and quenching the magnet. Moreover, there is the abil^¬ ity to force cool the coldhead with cold helium gas to pre^¬ vent warm gas quench.

Description of embodiments

Further features, properties and advantages of the present invention will become clear from the following description of embodiments in conjunction with the accompanying drawings. The embodiments do not limit the scope of the present inven^¬ tion which is determined by the appended claims. All de^¬ scribed features are advantageous as separate features or in any combination with each other.

Fig. 1 schematically shows a magnet arrangement in a sec- tional view along a centerline of the magnet.

Fig. 2 schematically shows a side view of a magnet and a sectional view of a turret and a cold head.

Fig. 3 schematically shows an inventive helium vessel port arrangement in a sectional view.

Fig. 4 schematically shows the inventive helium vessel

port arrangement with a first variant of a service siphon in a sectional view.

Fig. 5 schematically shows the inventive helium vessel

port arrangement with a second variant of a service siphon in a sectional view.

Fig. 6 schematically shows a sectional view of the in^¬ ventive helium vessel port arrangement while in^¬ serting a service siphon. The inventive helium vessel port arrangement for a magnetic resonance imaging (MRI) system, the helium vessel arrangement and the inventive method for operating the same will now be described with reference to figures 1 to 6.

Figure 1 schematically shows a magnet arrangement 1 in a sec^¬ tional view along a centerline 2 of the magnet 3. The magnet coils 3 are surrounded by a helium vessel 5 providing a heli^¬ um space 4. The helium vessel 5 is encased by a vacuum cham- ber 6. The vacuum chamber 6 comprises at least one radiation shield 7 and a vacuum space 8.

A turret 31 combined with a cold head is connected with the vacuum chamber. The turret comprises a port 30 for guiding helium into the helium vessel 5, which is connected with the helium vessel 5. The turret 31 further comprises a vent tube 20 and a tube or connection pipe 37 to a cold head sock. The vent tube 20 comprises a centerline 21. The port 30 is con^¬ nected with the tube or connection pipe 37 to a cold head sock.

A magnetic resonance imaging system will comprise further equipment (not illustrated) , such as gradient and field coils, shim coils and a patient table. One or more system electronics cabinet (s) house (s) a magnet supervisory system and other control and measurement equipment which control op^¬ eration of the magnet, and such further equipment, over communications lines. The magnet supervisory system receives data input from appropriate system sensors attached to vari- ous components of the MRI system. Helium compressor is typi^¬ cally an electromechanical device. It is conventionally me^¬ chanically enclosed within the system electronics cabinet (s) but the helium compressor is conventionally a standalone de^¬ vice .

Fig. 2 schematically shows a side view of a vacuum chamber 6 with a magnet 3 and a sectional view of a turret 31 com- bined with a cold head. The turret 31 comprises a cold head arrangement 9, the vent tube 20 and the port 30 into the he^¬ lium vessel 5. The cold head arrangement 9 comprises a cold head sock 19 and is connected with the port 30 via the tube or pipe 37. The vent tube 20 comprises a removable siphon tube 10.

Figure 3 schematically shows an inventive helium vessel port arrangement in a sectional view. The helium vessel port ar- rangement comprises the port 30 for guiding helium into a he^¬ lium vessel 5. The port 30 may be part of a turret 31. The port 30 comprises a siphon tube 32, a siphon cone 33 and a pipe or flow channel 34. The siphon cone 33 is in flow connection with the siphon tube 32.

The pipe or flow channel 34 comprises an inlet opening 35 and an outlet opening 36. The inlet opening 35 is configured for connecting it with the coldhead sock 19, more precisely for providing a flow connection with the cold head sock 19. The outlet opening 36 is in flow connection with the port 30 and the siphon cone 33. The flow direction of the helium, preferably liquid helium, is shown by arrow 38 into the siphon tube and by arrow 39 directly into the port 30. The port 30 comprises a port component 40. The port component 40 comprises a flow channel 44 with a first opening 41 con^¬ figured for connecting the flow channel 44 with a service si^¬ phon (not shown in figure 3) , a second opening 42 which is in flow connection with the siphon cone 33, and a third opening 43 which is in flow connection with the outlet opening 36 of the pipe 34.

The port 30 and/or the turret 31 may comprise a wall. In fig^¬ ure 3 the pipe 34 is positioned in the wall of the port 30 and/or the turret 31. For instance, the pipe 34 can be partly or completely positioned within the wall. The pipe 34 is preferably welded into the wall. Advantageously, the first opening 41 of the port component 40 is configured for aligning a service siphon, for example a standard helium service siphon, in the siphon cone 33.

Optionally, the inventive port arrangement comprises a sup^¬ port component 45 configured for maintaining alignment of a service siphon and/or for maintaining alignment of the port component 40 with respect to the siphon cone 33 and/or with respect to the outlet opening 36 of the pipe 34.

The first opening 41 of the port component 40 may comprise a centreline 46 and the second opening 41 of the port component 40 may comprise a centreline 47. The siphon cone 33 may com- prise a centreline 48, which corresponds with the centreline 46 of the first opening 41 and/or which corresponds with the centreline 47 the second opening 42 and/or which corresponds with a centreline 49 of a service siphon. In other words, the centreline of the siphon cone 33 may be an elongation of the centreline of the first opening 41 and/or the second opening 42 and/or a centreline 49 of a service siphon or the centre^¬ line of the siphon cone 33 may be identical with the centre^¬ line of the first opening 41 and/or the second opening 42 and/or a centreline 48 of a service siphon. This has the ad- vantage, that the service siphon can easily be inserted and fitted into the siphon cone 33.

Furthermore, the third opening 43 may comprise a centreline 68, which may run perpendicular to the centreline 46 of the first opening 41 and/or perpendicular to the centreline 47 of the second opening 42.

The port arrangement optionally comprises a vessel examina^¬ tion tube 50, which is configured for inserting a service si- phon into the port component 40. The vessel examination tube 50 may comprise an outer tube 51 and an inner tube 52 and may be configured for inserting the service siphon into the port component 40 via the outer tube 51. In figure 3 the vessel examination tube 50 is for example welded into the wall of the port 30 or into the turret 31. The port arrangement can generally comprise a turret 31, which comprises the port com- ponent 40.

Figure 4 schematically shows the port arrangement of figure 3 with a first variant of a service siphon 53 in a sectional view. Generally, the service siphon 53 is preferably a helium siphon. The service siphon 53 comprises a tip 54 comprising an opening 55, wherein the tip 54 is fitted into the port component 40 and configured such that the third opening 43 of the port component 40 and the outlet opening 36 of the pipe 34 are closed by means of the tip 54. The opening 55 of the tip 54 is in flow connection 56 with the siphon cone 33. The flow direction of the helium, preferably liquid helium, from the service siphon 53 into the siphon tube 32 via the siphon cone 33 is shown by an arrow 56. With this configuration helium from the service siphon 53 can be guided into the port 30 and further into the helium vessel 5, for example while the coldhead can be exchanged can be carried out without ramping down the magnet. Figure 5 schematically shows the port arrangement with a sec^¬ ond variant of a service siphon 63 in a sectional view. The service siphon 63 with a tip 64. The tip 64 comprises an opening 67. The tip 64 is fitted into the port component 40 and configured such that the siphon cone is closed by means of the tip 64, for example using a means for closing the si^¬ phon cone 65. The opening 67 of the tip 64 is in flow connec^¬ tion with the third opening 43 of the port component and with the outlet opening 36 of the pipe 34. Preferably the opening 67 of the tip 64 is only in flow connection with the third opening 43 of the port component 40 and with the outlet open^¬ ing 37 of the pipe 34. With this configuration the pipe 34 and for example a cold- head sock can be provided with helium, for instance liquid or gaseous helium, from the service siphon 63. By means of the described tip 64 the coldhead sock can be isolated from the port 30 and from the helium vessel 5 or from the turret 31. The configuration can be used to de-ice a connecting tube 37. Moreover, by guiding helium gas into the pipe 34 from the outlet opening 36 towards the inlet opening 35 air ingress during coldhead exchange can be prevented. The tip 64 can re- main in place until the coldhead has cooled down. The cold- head can be force cooled by using cold helium through the service siphon and venting via a transit line and a valve, for example a bypass valve. Figure 6 schematically shows a sectional view of the in^¬ ventive port arrangement while inserting a service siphon 53, as described in conjunction with figure 3. Alternatively a service siphon 63, as described in conjunction with figure 4, can be inserted. This is the position of the syphon for top- ping up the magnet with helium.

While the present application has been described with par^¬ ticular reference to cooling using helium cryogen, the present invention may be applied to superconducting magnets cooled by other cryogens, such as hydrogen, nitrogen, neon, argon .

Claims

1. A cryogen vessel port arrangement for a magnetic resonance imaging (MRI) system comprising a port (30) for guiding cryo- gen into a cryogen vessel (5), the port (30) comprising a si^¬ phon tube (32), a siphon cone (33), which is in flow connection with the siphon tube (32), and a pipe (34) with an inlet opening (35) and an outlet opening (36) , wherein the inlet opening (35) is configured for connecting it with a coldhead sock and the outlet opening (36) is in flow connection with the port (30) and the siphon cone (33),

characterised in that

the port (30) comprises a port component (40) which comprises a flow channel (44) with a first opening (41) configured for connecting it with a service siphon (53, 63) , a second open^¬ ing (42) which is in flow connection with the siphon cone

(33) , and a third opening (43) which is in flow connection with the outlet opening (36) of the pipe (34) .

2. The cryogen vessel port arrangement, as claimed in the previous claim,

characterised in that

the first opening (41) is configured for aligning the service siphon (53, 63) in the siphon cone (33) .

3. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

it comprises a support component (45) configured for main- taining alignment of a service siphon (53, 63) and/or of the port component (40) with respect to the siphon cone (33) and/or with respect to the outlet opening (36) of the pipe

(34) .

4. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that the pipe (34) is positioned in the wall of a turret (31)

5. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

the first opening (41) comprises a centreline (46), the sec^¬ ond opening (42) comprises a centreline (47) and the siphon cone (33) comprises a centreline (48), which corresponds with the centreline (46) of the first opening (41) and/or the sec- ond opening (42) and/or a centreline (49) of a service siphon (53, 63) .

6. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

it comprises a vessel examination tube (50), which is config^¬ ured for inserting a service siphon (53, 63) into the port component (40).

7. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

it comprises a service siphon (53) with a tip (54) comprising an opening (55), wherein the tip (54) is fitted into the port component (40) and configured such that the third opening (43) of the port component (40) and/or the outlet opening (36) of the pipe (34) is closed by means of the tip (54) and the opening (55) of the tip (54) is in flow connection with the siphon cone (33) .

8. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

it comprises a service siphon (63) with a tip (64) comprising an opening (67), wherein the tip (64) is fitted into the port component (40) and configured such that the siphon cone (33) is closed by means of the tip (64, 65) and the opening (67) of the tip (64) is in flow connection with the third opening (43) of the port component (40) and/or the outlet opening (36) of the pipe (34) .

9. The cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

the service siphon (53, 63) is a cryogen siphon.

10. A cryogen vessel arrangement comprising a cryogen vessel port arrangement, as claimed in any of the previous claims.

11. A method for operating a cryogen vessel port arrangement, as claimed in any of the previous claims,

characterised in that

cryogen is guided into the inlet (35) of the pipe (34), through the pipe (34) and via the outlet (36) of the pipe (34) into the port (30) for guiding cryogen into a cryogen vessel .

12. The method for operating a cryogen vessel port arrange^¬ ment, as claimed in the previous claim,

characterised in that

cryogen is guided into the inlet (35) of the pipe (34), through the pipe (34) and via the outlet (36) of the pipe

(34) into the siphon cone (33) and into the siphon tube (32) .

13. The method for operating a cryogen vessel port arrange^¬ ment, as claimed in any of the previous claims,

characterised in

closing the third opening (43) of the port component (40) and/or the outlet opening (36) of the pipe (34), and guiding cryogen from the service siphon (53) into the siphon cone (33) and into the siphon tube (32) .

14. The method for operating a cryogen vessel port arrange^¬ ment, as claimed in claim 11 or claim 12, characterised in

closing the siphon cone (33) by means of the tip (65) of the service siphon (63) and guiding cryogen from the service si^¬ phon (63) into the third opening (43) of the port component (40) and/or the outlet opening (36) of the pipe (34) .

15. A method according to any of claims 11-14 wherein the cryogen comprises helium.

16. A magnetic resonance imaging system comprising a cryogen vessel port arrangement and/or a cryogen vessel arrangement, as claimed in any of claims 1-10.