Particulate tester with mixer for analytical application

• US 7,789,552 B2
• Filed: 08/18/2006
• Issued: 09/07/2010
• Est. Priority Date: 08/18/2005
• Status: Expired due to Fees

• Current Assignee: Hach Company (Veralto Corp.)
• Original Assignee: Hach Company (Veralto Corp.)
• Inventors: Szpak, Gerald A., Bender, Keith A., Hogan, Shawn A., Girvin, Kenneth L., Moss, Robert A.
• Primary Examiner(s): Sorkin; David L
• Application Number:
  US11/506,545
• Publication Number:
  US 20070047385A1
• Time in Patent Office: 1,481 Days
• Field of Search: 366/142, 366/208, 366/209, 366/213, 366/219, 366/220, 366/232, 366/140
• US Class Current: 366/140
• CPC Class Codes: B01F 31/22 with supporting means moving in a horizontal plane, e.g. describing an orbital path for moving the containers about an axis which intersects the receptacle axis at an angle
• CPC Class Codes: G01N 21/534 by measuring transmission alone, i.e. determining opacity

Abstract

A mixer for analytical application mixes a container of fluid without a magnetic stir bar. A device for testing a liquid for particles can use the mixer. The mixing can occur in a sealed container, and liquid can be transmitted to the device from the sealed container.

Claims

1. A stirring mechanism for noninvasive mixing of liquid and particulate matter held in a container, comprising:

a support configured to receive the container;

a drive mechanism operatively coupled to the support to impart to the container a non-circular path of motion that induces substantially uniform mixing of the liquid and the particulate matter held in the container;

the support including a coupling feature and the drive mechanism including a drive feature that cooperates with the coupling feature of the support to produce directional components of the non-circular path of motion, the directional components activating in the liquid a vortex that is capable of generating sufficient lift of the particulate matter and linear motion of an amount sufficient to introduce into the vortex a degree of chaos that thoroughly mixes the particulate matter in the liquid;

a particulate matter-detecting sensor; and

a sample conduit that is capable of transmitting to the particulate matter-detecting sensor the liquid thoroughly mixed with particulate matter.

2. The stirring mechanism of claim 1, in which the non-circular path of motion is substantially elliptical.

3. The stirring mechanism of claim 1, in which:

the non-circular path of motion is in a substantially horizontal plane;

the support is configured to hold the container substantially perpendicular to the substantially horizontal plane; and

the container is a sealed bottle.

4. The stirring mechanism of claim 3, in which the support includes a drive plate, and further comprising:

a drive plate first end comprising a linear cam;

a drive plate second end, substantially diametrically opposed to the drive plate first end, being driven by an eccentric drive;

a motor that drives the eccentric drive;

whereby the linear cam and eccentric drive cooperate to impart a substantially elliptical motion to the drive plate.

5. The stirring mechanism of claim 4 in which the linear cam constrains the drive plate second end to a substantially linear motion in the substantially horizontal plane.

6. The stirring mechanism of claim 1, in which the container includes a penetrable closure to form a sealed container, and further comprising a conduit configured to penetrate the penetrable closure and to withdraw the liquid from the container while the drive mechanism imparts to the container the non-circular path of motion.

7. The stirring mechanism of claim 6, in which:

the container has a narrow end; and

the support is configured to hold the container so that the narrow end is positioned downward and so that the conduit withdraws the liquid from the narrow end.

8. The stirring mechanism of claim 1, in which the drive feature includes an eccentric drive having an eccentric drive shaft and driven by a motor, and in which the eccentric drive shaft and the coupling feature of the support cooperate to provide rotational coupling of the eccentric drive shaft to the support.

9. The stirring mechanism of claim 8, in which the motor has a stationary guide bearing, and in which the support includes a drive plate having a linear guide and the coupling feature is in the form of a hole, the linear guide and the hole positioned relative to each other on the drive plate to receive, respectively, the guide bearing and the eccentric drive shaft so that the eccentric drive imparts substantially elliptical motion to the drive plate.

10. The stirring mechanism of claim 9, in which the non-circular path of motion is oriented in a substantially horizontal plane and in which the linear guide receiving the guide bearing is constrained to substantially linear motion in the substantially horizontal plane.

11. The stirring mechanism of claim 1, in which the particulate matter-detecting sensor is of a light obscuration sensor type.

12. The stirring mechanism of claim 1, in which the particulate matter-detecting sensor is of a light scattering type.

13. The stirring mechanism of claim 1, in which the container is closed, and in which the sample conduit includes an end that is capable of penetrating the container.

14. The stirring mechanism of claim 13, in which the end is a needle.

15. The stirring mechanism of claim 1, in which the container has a narrow end, and in which the support is configured to receive the container such that the narrow end is oriented in a downward position to enable the sample conduit to withdraw from the narrow end the liquid thoroughly mixed with particulate matter.

16. The stirring mechanism of claim 1, in which the liquid held in the container has a top level, and further comprising:

a vent conduit that is capable of venting to air or other gas a vacuum produced at the top level by the transmitting to the particulate matter-detecting sensor the liquid thoroughly mixed with particulate matter.

17. The stirring mechanism of claim 16, in which the container is closed, each of the sample and vent conduits has an end that is capable of penetrating the container, and the end of the vent conduit is set above the top level.

18. The stirring mechanism of claim 17, in which each of the ends of the sample and vent conduits is a needle.