SAFETY DEVICE FOR A SINGLE-USE MIXING OR STORAGE SYSTEM

Abstract

A safety device for a single-use mixing or storage system (10), especially for use in a biopharmaceutical process, includes a flexible bag (12) made from a film material and a support structure (14) receiving and supporting the bag (12) in several directions. The support structure (14) allows an expansion of the bag (12) in an expansion direction. The safety device further includes a detection unit (20) adapted to detect an expansion of the bag (12) in the expansion direction, and a control unit (28) connected to the detection unit (20) and adapted to initiate a safety measure in response to the expansion of the bag (12) in the expansion direction exceeds a given threshold.

Claims

1. A safety device for a single-use mixing or storage system for use in a biopharmaceutical or other process, the safety device comprising: a flexible bag made from a film material, a support structure configured to receive and support the bag in plural directions, wherein the support structure allows an expansion of the bag in an expansion direction, a detection unit adapted to detect the expansion of the bag in the expansion direction, and a control unit connected to the detection unit and adapted to initiate a safety measure in response to a detection of the expansion of the bag in the expansion direction that exceeds a given threshold.

2. The safety device according to claim 1, wherein the detection unit includes a sensor element arranged to come into or be in contact with the bag when the bag expands so that the sensor element is translated or rotated by the expansion of the bag in the expansion direction.

3. The safety device according to claim 2, wherein the detection unit further includes a trigger element emitting a trigger signal to the control unit in response to the expansion of the bag in the expansion direction exceeding the threshold.

4. The safety device according to claim 3, wherein the trigger element includes a photoelectric sensor.

5. The safety device according to claim 2, wherein the detection unit further includes a trigger element physically performing a switching operation in response to the expansion of the bag in the expansion direction exceeding the threshold.

6. The safety device according to claim 5, wherein the trigger element includes a contact switch.

7. The safety device according to claim 2, wherein the sensor element includes a pivotable lever.

8. The safety device according to claim 7, wherein the pivotable lever is mounted to the support structure by a mechanical bearing.

9. The safety device according to claim 6, wherein the trigger element includes an angle sensor.

10. The safety device according to claim 1, wherein the control unit is connected to a filling component configured to control a fluid transfer into the bag.

11. The safety device according to claim 10, wherein the filling component comprises a pump configured to control the fluid transfer into the bag.

12. The safety device according to claim 1, wherein the control unit is connected to an alarm system to initiate an audible or visual alarm as the safety measure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further features and advantages of the invention will become apparent from the following description and from the accompanying drawings to which reference is made. In the drawings:

[0021] FIG. 1A shows a single-use mixing or storage system according to the prior art in normal operation;

[0022] FIG. 1B shows the mixing or storage system of FIG. 1A in case of an overpressure;

[0023] FIG. 2A shows a safety device for a single-use mixing or storage system according to the invention in normal operation; and

[0024] FIG. 2B shows the safety device of FIG. 2A in case of an overpressure.

DETAILED DESCRIPTION

[0025] FIG. 1A is a simplified illustration of a single-use mixing or storage system 10 as used in a biopharmaceutical process. A flexible bag 12 made of a film material is accommodated in a fixed, rigid holder made of stainless steel or hard plastic. The bag 12 may be empty or already partially filled with a fluid. In any case, no additional pressure acts on the bag 12.

[0026] The holder serves as a support structure 14 for receiving and supporting the bag 12 in several directions. In particular, the bag 12 is completely enclosed by the support structure 14 except for the top. This is a typical design allowing an operator to easily install the bag 12 inside the support structure 14 before operation and to easily remove the bag 12 from the support structure 14 after operation.

[0027] In the depicted example, a fluid is to be transferred from a reservoir 16 into the bag 12 by an electrically driven pump 18 or another filling component. The mixing or storage system 10 is not pressurized during normal operation. This means that the air contained in the bag 12 is displaced through a vent filter (not shown) when the fluid from the reservoir 16 is filled into the bag 12.

[0028] However, if the bag 12 is filled too quickly, overfilled or if the vent filter is blocked or in the event of another fault, the pressure in the bag 12 can rise in an uncontrolled manner as shown in FIG. 1B. Due to the overpressure, the bag 12 expands, especially in the upward direction where the support structure 14 does not confine the bag 12. The upward direction will thus be referred to as the main expansion direction A.

[0029] If further expansion of the bag 12 is no longer possible, especially owing to limited material strength, the bag 12 can rupture or burst. Such damage to the bag 12 must be avoided, not only for economic and process efficiency reasons (the process has to be stopped and valuable medium is lost), but above all to protect the operator, especially in case of toxic content of the bag 12.

[0030] FIG. 2A illustrates an embodiment of a safety device for a single-use mixing or storage system 10 which is similar to the single-use mixing or storage system 10 shown in FIG. 1A. The safety device comprises a detection unit 20 adapted to detect an expansion of the bag 12 in the main expansion direction A.

[0031] In the depicted example embodiment, the detection unit 20 includes a sensor element 22 that is in contact with or comes into contact with the bag 12 when the bag 12 expands. As a result, the sensor element 22 is displaced by the expansion of the bag 12 in the main expansion direction A. In particular, the sensor element 22 is a displaceable or pivotable element, such as a rod, a bar, or a lid, for example, and is hereinafter referred to as lever. The lever either rests on the bag 12 or takes a (predefined) initial position during normal operation of the mixing or storage system 10. The lever may be supported and/or guided to perform a defined displacement or pivoting movement. For example, the lever can be attached to the support structure 14 by a hinge 24 or another suitable mechanical bearing.

[0032] The detection unit 20 further includes a trigger element 26 which is connected to a control unit 28 of the safety device. The control unit 28 is adapted to initiate a safety measure when triggered by the detection unit 20. To this end, the sensor element 22 interacts with the trigger element 26 when the expansion of the bag 12 in the main expansion direction A exceeds a given threshold. This situation is shown in FIG. 2B.

[0033] According to the example embodiment described here, the sensor element 22, i.e. the pivotable lever, is rotated by the expanding bag 12 until it physically acts on a contact switch constituting the trigger element 26. The contact switch is part of an electric circuit monitored by the control unit 28. As soon as the control unit 28 recognizes this switching operation, a safety measure is initiated to prevent the bag 12 from being damaged.

[0034] The control unit 28 may be connected to an alarm system and/or to the pump 18, so that an alarm can be triggered and/or the pump 18 can be shut down to prevent a further increase of pressure in the bag 12. Other safety measures can be initiated as well.

[0035] Instead of the contact switch, the detection unit 20 may include an angle sensor. According to this alternative, the safety measure is initiated as soon as the angle sensor detects that the pivotable lever has reached a given angular position due to a rotation of the lever caused by the expanding bag 12.

[0036] In an alternative embodiment, the trigger element 26 of the detection unit 20 does not require any physical contact with a sensor element 22 or directly with the bag 12 to emit a trigger signal to the control unit 28 in case the expansion of the bag 12 exceeds the threshold. For example, the trigger element 26 can include a photoelectric sensor. As soon as the photoelectric sensor detects an excessive expansion of the bag 12 in the main expansion direction A, the trigger signal is sent to the control unit 28, and the control unit 28 promptly initiates the safety measure.

[0037] It is to be noted that the bag 12 (possibly including pre-installed elements such as ports and directly connected hose lines etc.) is a dedicated single-use component, whereas the other components of the safety device, including the support structure 14, the sensor element 22 and the optional trigger element 26, are usually reusable, i.e. they are not configured as single-use components, although single-use configurations are not necessarily precluded.

LIST OF REFERENCE SIGNS

[0038] 10 single-use mixing or storage system [0039] 12 bag [0040] 14 support structure [0041] 16 reservoir [0042] 18 pump [0043] 20 detection unit [0044] 22 sensor element [0045] 24 hinge [0046] 26 trigger element [0047] 28 control unit