Rotating evaporator with process-dependent rotating speed regulation

• US 20030000651A1
• Filed: 03/14/2002
• Published: 01/02/2003
• Est. Priority Date: 03/23/2001
• Status: Active Grant

• Current Assignee: Hans Georg Genser
• Original Assignee: Hans Georg Genser
• Inventors: Genser, Hans Georg
• Granted Patent: US 7,153,396 B2
• Time in Patent Office: Days
• US Class Current: 159/6.1
• CPC Class Codes: B01D 3/085 using a rotary evaporator
• CPC Class Codes: B01D 3/42 Regulation; Control

Abstract

In a rotary evaporator, the rotating speed of the rotating flask is automatically controlled or regulated dependent upon a detected process value, particularly the vibration behavior or the mass moment of inertia of the rotating flask.

Advantage: greater evaporation capacity

Claims

1. Device for evaporating at least one substance with

a) a rotary container (2) for receiving a medium (M), that comprises the at least one substance to be evaporated or consists of it or them,

b) a drive means (6) to rotate the rotary container around an axis of rotation (R) inclined against the direction of gravity (G) and with

c) a control mechanism (60, 14, 15, 16) in an active connection with the drive means

c1) to detect at least one process value and

c2) to automatically control or regulate the speed of the rotary container depending on the process value/s detected,

wherein

d) the control mechanism controls or regulates the rotary speed of the rotary container in such a way that in the lower area of the rotary container, there is a reservoir of the medium drawn downward by gravity and out of which, at least on a portion of the inner wall of the rotary container, a film of the medium (MF) is formed that is preferably at least approximately uniform and/or favorable for the evaporation and is constantly at least partially renewed.

2. Device according to claim 1, in which at least one substance to be evaporated or the medium is essentially liquid.

3. Device according to one of the preceding claims, in which the at least one substance to be evaporated or the medium consists essentially of solid particles, particularly in powder or granulate form.

4. Device according to claim 3, in which the control mechanism controls or regulates the rotary speed of the rotating container so as to produce the best possible mixing of the particles of the substance/s to be evaporated or of the medium.

5. Device according to one or more of the preceding claims, in which the control mechanism controls or regulates the rotating speed of the rotating container so as to produce the best possible heat transfer within the substance/s to be evaporated or the medium.

6. Device according to one or more of the preceding claims, with a heat transfer bath (3), into which the rotating container is or can be at least partially dipped during operation and by means of which the rotating container is or can be brought to temperatures suitable for evaporating the substance/s to be evaporated.

7. Device according to one or more of the preceding claims, in which the rotating container is also able to swivel around a swiveling axis (5) freely at least in a predetermined swivel area, and the control mechanism detects a pivoting angle (α

) of the rotating container relative to a reference position (H′

) as the process value.

8. Device according to one or more of the preceding claims, in which the axis of rotation concurs with a primary axis of inertia of the rotating container, preferably with an axis of symmetry with respect to which the rotating container is designed rotationally symmetrical.

9. Device according to one or more of the preceding claims, in which the control mechanism detects as process value the vibration behavior, particularly a resonance behavior, of the rotating container or of a body mechanically connected with the rotating container, particularly the drive means or parts thereof such as, for example, a drive shaft or a transfer mechanism or the heat transfer bath.

10. Device according to one or more of the preceding claims, in which the control mechanism detects as process value/s the mass distribution, mass moment of inertia and/or a change in the mass distribution or, respectively, in the mass moment of inertia of the substance/s to be evaporated or of the medium.

11. Device according to claim 10, in which the control mechanism detects the mass moment of inertia by measuring the time required to accelerate or slow down the rotating container from a first rotating speed to a second rotating speed.

12. Device according to one or more of the preceding claims, in which the control mechanism controls or regulates the rotating speed of the rotating container depending on a comparison of the current process value detected with the rotating container filled with the substance/s on the one hand and, on the other hand, the reference process value detected beforehand when the rotating container is not filled with the substance/s.

13. Device according to one or more of the preceding claims, in which the control mechanism detects as process value the drive power required of the drive means in order to rotate the rotating container.

14. Device according to one or more of the preceding claims, in which the control mechanism (60, 14, 15) detects as process value a foam formation in the rotating container.

15. Device according to one or more of the preceding claims, in which the control mechanism detects the process value for at least two different rotation angle positions of the rotating container and controls or regulates the rotating speed depending on the measured values of the process value for these at least two different rotation angle positions.

16. Device according to claim 15, in which the control mechanism controls or regulates the rotating speed depending on the measured values of the process value for the at least two different rotation angle positions in such a way that discrepancies between these measured values are within a predefined tolerance range.

17. Device according to one or more of the preceding claims, in which the drive means is designed so that it is possible for the rotating container to rotate in both rotation directions around the axis of rotation, and the control mechanism changes the direction of rotation of the rotating container in a predetermined manner, particularly at regular intervals.

18. Device according to claim 17, in which the control mechanism controls or regulates the turning direction of the rotating container depending on at least one process value.

19. Device according to one of the preceding claims, in which the control mechanism detects as process value the viscosity of the medium situated in the rotating container.

20. Device according to one of the preceding claims, in which the control mechanism maintains as process value a relative speed between the rotating container and the medium situated in the rotating container.

21. Device according to one or more of the preceding claims, in which the control mechanism to detect at least one process value comprises one or more sensors (14, 15, 16) from the group comprising the following sensors:

acoustic sensors;

sensors measuring electromagnetic rays, particularly optic or infrared sensors or radar sensors;

position sensors, particularly level sensors, position sensors or angle position indicators such as inclinometers, sensors detecting electric and/or magnetic fields, particularly capacitive or inductive sensors, field strength sensors;

power and/or force and/or weight sensors;

expansion sensors, electric current or output sensors.

22. Process for evaporating at least one substance, in which

a) a medium (M) that contains the at least one substance to be evaporated or consists of it is introduced into a rotating container (2),

b) the rotating container is rotated around an axis of rotation (R) inclined against gravity,

c) at least one process value is detected and

d) depending on the at least one process value detected, the rotating speed of the rotating container is automatically controlled or regulated in such a way that in the lower area of the rotating container, a reservoir of the medium drawn downward by gravity is formed out of which, at least on a portion of the inner wall of the rotating container, a film of the medium is generated that is preferably at least approximately uniform and/or favorable for the evaporation and is constantly at least partially renewed.

23. Process according to claim 22, in which at least one substance to be evaporated or the medium is essentially liquid.

24. Process according to one or more of claims 22 and 23, in which at least one substance to be evaporated or the medium consists essentially of solid particles, particularly in powder or granulate form.

25. Process according to claim 24, in which the rotating speed of the rotating container is controlled or regulated so as to achieve the best possible mixing of the particles of the substance/s to be evaporated or of the medium.

26. Process according to one or more of claims 22 through 25, in which the rotating speed of the rotating container is controlled or regulated so as to achieve the best possible heat transfer within the substance/s to be evaporated or the medium.

27. Process according to one or more of claims 22 through 26, in which the vibration behavior, particularly a resonance behavior, of the rotating container or of a body mechanically connected with the rotating container, particularly the drive means or a carrier unit, is detected as the process value.

28. Process according to one or more of claims 22 through 27, in which the mass distribution, the mass moment of inertia and/or a change in the mass distribution or the mass moment of inertia of the substance/s to be evaporated or of the medium in the rotating container is detected as the process value/s.

29. Process according to one or more of claims 22 through 28, in which the rotating speed of the rotating container is controlled or regulated depending on a comparison of the current process value detected with the rotating container filled with the substance/s on the one hand and, on the other hand, the reference process value detected beforehand when the rotating container is not filled with the substance/s.

30. Process according to claim 28 or claim 29, in which the mass moment of inertia is detected by measuring the time required to accelerate or to slow down the rotating container from a first rotating speed to a second rotating speed.

31. Process according to one or more of claims 22 through 30, in which the drive power required to rotate the rotating container is detected as the process value.

32. Process according to one or more of claims 22 through 31, in which the rotating container can be swiveled around a swiveling axis (S) and a pivoting angle (α

) of the rotating container relative to a reference position is detected as the process value.

33. Process according to one or more of claims 22 through 32, in which a foam formation in the rotating container is detected as the process value.

34. Process according to one or more of claims 22 through 33, in which the process value is detected at at least two different rotation angle positions of the rotating container and the rotating speed is controlled or regulated depending on the measured values of the process value for these at least two different rotation angle positions.

35. Process according to claim 34, in which the rotating speed is controlled or regulated depending on the measured values of the process value for the at least two different rotation angle positions in such a way that discrepancies between these measured values are within a predefined tolerance range.

36. Process according to one or more of claims 22 through 35, in which the direction of rotation of the rotating container is changed in a predetermined manner, particularly at regular intervals.

37. Process according to claim 36, in which the direction of rotation of the rotating container is controlled or regulated depending on at least one process value.

38. Process according to one or more of claims 22 through 37, in which the rotating container is rotated in a heat transfer bath (3) and is thereby brought to temperatures suitable for evaporating the substance/s to be evaporated.

39. Process according to one of claims 22 through 38, in which the viscosity of the medium that is in the rotating container is detected as the process value.

40. Process according to one of claims 22 through 39, in which as the process value, a relative speed between the rotating container and the medium is kept above a specific minimum value.