Apparatus for controllably mixing and delivering diluted solution

• US 6,572,255 B2
• Filed: 04/24/2001
• Issued: 06/03/2003
• Est. Priority Date: 04/24/2001
• Status: Expired due to Term

• Current Assignee: Coulter International Corp.
• Original Assignee: Coulter International Corp.
• Inventors: Husher, Frederick K.
• Primary Examiner(s): Cooley, Charles E.
• Application Number:
  US09/841,267
• Publication Number:
  US 20020154567A1
• Time in Patent Office: 770 Days
• Field of Search: 366/132, 366/134, 366/136, 366/137, 366/138, 366/142, 366/152.1, 366/152.4, 366/159.1, 366/160.1, 137/3, 137/5, 137/93, 137/563
• US Class Current: 366/132
• CPC Class Codes: B01F 2101/2202 Mixing compositions or mixers in the medical or veterinary field
• CPC Class Codes: B01F 23/483 using water for diluting a liquid ingredient, obtaining a predetermined concentration or making an aqueous solution of a concentrate
• CPC Class Codes: B01F 23/49 Mixing systems, i.e. flow charts or diagrams
• CPC Class Codes: B01F 35/145 Washing or cleaning mixers not provided for in other groups in this subclass; Inhibiting build-up of material on machine parts using other means
• CPC Class Codes: B01F 35/2132 Concentration, pH, pOH, p(ION) or oxygen-demand B01F35/2133 takes precedence
• CPC Class Codes: B01F 35/82 by adding a material to be mixed to a mixture in response to a detected feature, e.g. density, radioactivity, consumed power or colour
• CPC Class Codes: B01F 35/834 the flow of substances to be mixed circulating in a closed circuit, e.g. from a container through valve, driving means, metering means or dispensing means, e.g. 3-way valve, and back to the container
• CPC Class Codes: G01F 23/74 for sensing changes in level only at discrete points
• CPC Class Codes: G01N 1/38 Diluting, dispersing or mixing samples
• CPC Class Codes: G01N 15/1404 Handling flow, e.g. hydrodynamic focusing
• CPC Class Codes: G01N 15/1409 Handling samples, e.g. injecting samples
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G05D 11/138 by sensing the concentration of the mixture, e.g. measuring pH value

Abstract

A physically compact (saline) solution preparation apparatus includes a solution mixing tank coupled to sources of concentrate and diluent. A concentrate transport path is configured to both homogenize and deliver concentrate to the mixing tank, while the diluent transport path is controllably purged of potential contaminates prior to supplying the diluent to the mixing tank. A mixed solution transport path recirculates and thereby homogenizes the contents of the mixing container, and actively pumps out solution that has been mixed to a prescribed conductivity-based concentration, to one or more solution on demand storage reservoirs for respective instruments. The operation of the apparatus is based upon measured conductivity of the contents of the solution mixing tank, so that there is no need to conduct precursor volumetric measurements of either diluent or concentrate.

Claims

1. An apparatus for providing a solution of a diluent and a prescribed concentration of a component diluted therein comprising:

a solution mixing container to which said component and said diluent are supplied, and from which said solution is controllably deliverable to a solution delivery port;

a component storage container, in which said component is stored;

a first fluid transport path, through which said component stored in said component storage container is controllably supplied from said component storage container to said solution mixing container;

a component recirculation path through which said component stored in said component storage container is controllably recirculated from and back into said component storage container so as to maintain uniformity of said component in said component storage container;

a second fluid transport path through which said diluent is controllably supplied from a source of said diluent to said solution mixing container;

a second fluid transport path purger, which controllably purges said second fluid transport path of potential contaminates prior to said second fluid transport path controllably supplying said diluent to said solution mixing container;

a third fluid transport path coupled to said solution mixing container and to said solution delivery port, and including a mixed solution recirculation path through which contents of said solution mixing container are controllably recirculated from and back into said solution mixing container, and a mixed solution extraction path through which contents of said solution mixing container are controllably delivered to said solution delivery port; and

a controller which controls the operations of said first fluid transport path, said second fluid transport path, said second fluid transport path purger, said mixed solution recirculation path and said mixed solution extraction path in accordance with the conductivity of the contents of said solution mixing container, to realize therein said solution of said diluent and said prescribed concentration of diluted component.

2. The apparatus according to claim 1, wherein said second fluid transport path includes a variable rate of delivery path structure, that is controlled by controller to supply said diluent to said solution mixing container at a variable rate of delivery.

3. The apparatus according to claim 1, further comprising:

a mixed solution storage reservoir having an input port to which contents of said solution mixing container are controllably delivered by way of said mixed solution extraction path, and an output through which solution stored in said reservoir is supplied to a solution utility device; and

a leak sensor coupled with said mixed solution reservoir and being operative to generate an indication representative of a leakage condition of said reservoir.

4. The apparatus according to claim 3, further comprising:

a waste container coupled to receive and store waste liquid from said second fluid transport path purger and waste contents of said solution mixing container from said third fluid transport path; and

a fourth fluid transport path through which contents of said waste container are controllably removed from said waste container to a waste output port.

5. The apparatus according to claim 1, wherein said component storage container has a variable orientation relative to said first fluid transport path that enables substantially the entire contents of said component storage container to be extracted by said first transport path and delivered to said mixing container.

6. The apparatus according to claim 1, wherein said solution mixing container has a mixed solution output port coupled to a said mixed solution extraction path, and a mixed solution recirculation input port coupled to a said mixed solution recirculation path, and further including a mixed solution concentration sensor coupled to a location of said solution mixing container between said mixed solution recirculation input port and said mixed solution output port, so that as mixed solution is recirculated from said mixed solution output port through said mixed solution recirculation path and reenters said solution mixing container by way of said mixed solution recirculation input port, it flows through said solution mixing container past said mixed solution concentration sensor and prevents formation of an unwanted characteristic on said mixed solution concentration sensor.

7. The apparatus according to claim 1, wherein said second fluid transport path includes a diluent supply valve that is controlled by said controller to supply said diluent through said second fluid transport path to to said solution mixing container, and wherein said first fluid transport path includes a first fluid transport path valve arrangement that is controlled by said controller to supply homogenized component from said component storage container to said solution mixing container, and wherein said component recirculation path includes a component recirculation valve arrangement that is controlled by said controller to thereafter recirculate contents of said component storage container as said diluent is iteratively supplied to said solution mixing container by said second fluid transport path until the conductivity of contents of said solution mixing container satisfies a prescribed criterion.

8. The apparatus according to claim 1, wherein said second fluid transport path includes a diluent supply valve that is controlled by said controller to iteratively supply said diluent through said second fluid transport path to said solution mixing container, as contents thereof are recirculated by way of said component recirculation path, in accordance with a prescribed solution conductivity characteristic.

9. The apparatus according to claim 8, wherein said solution mixing container has a conductivity sensor coupled to a recirculation flow path therethrough, so that solution recirculated through said solution mixing container flows past said conductivity sensor and prevents formation of an unwanted characteristic thereon.

10. The apparatus according to claim 9, wherein said conductivity sensor has a four contact, in-line configuration.

11. The apparatus according to claim 9, wherein said mixed fluid extraction path of said third fluid transport path is coupled from said solution mixing container to said mixed solution delivery port through a check valve that allows multiple ones of said apparatus to be connected together and realize a redundant system for supplying said solution to one or more mixed solution storage reservoirs, from which said solution is supplied to respective utility devices.

12. A method for preparing a solution containing a diluent having a prescribed concentration of a component diluted therein comprising the steps of:

(a) providing a solution mixing container;

(b) providing a component storage container having a fluid concentration of said component;

(c) supplying said diluent to said solution mixing container over a diluent transport path, while recirculating contents of said component storage container through a component transport path to maintain mixture uniformity of said component stored in said component storage container;

(d) recirculating contents of said solution mixing container through a solution transport path, while controllably supplying fluid component stored in said component storage container through said component transport path to said solution mixing container; and

(e) iteratively controlling the operation of said diluent and solution transport paths in accordance with the conductivity of the contents of said solution mixing container, to realize therein said solution of said diluent and said prescribed concentration of said component.

13. A method according to claim 12, wherein step (e) comprises iteratively causing said diluent fluid transport path to supply said diluent to said solution mixing container, while recirculating contents thereof by way of said solution transport path, in accordance with a prescribed solution conductivity characteristic.

14. A method according to claim 12, wherein step (e) includes monitoring the conductivity of contents of said solution mixing container by means of a conductivity sensor coupled to a recirculation flow path therethrough, so that solution recirculated through said solution mixing container flows past said conductivity sensor and prevents formation of an unwanted characteristic thereon.

15. A method according to claim 14, wherein said conductivity sensor has a four contact, in-line configuration.

16. A method according to claim 14, wherein said solution transport path is coupled from said solution mixing container to an output port through a check valve that allows solution transport paths of multiple solution mixing containers to be connected together and provide for redundant supply of said solution to one or more mixed solution storage reservoirs, from which said solution may be controllably supplied to respective utility devices.

17. A method according to claim 12, wherein step (e) comprises controllably varying the rate of supply of said diluent to said solution mixing container.

18. A method according to claim 12, further comprising the steps of:

(f) controllably delivering contents of said solution mixing container by way of said solution transport path to a storage reservoir having an output through which solution stored in said reservoir is supplied to a solution utility device; and

(g) monitoring said storage reservoir for a potential leak condition.

19. A method according to claim 18, which further comprises (h) refilling a storage reservoir which is refilled through a demand valve selectively activated by the passage of time or empty condition so as to keep the reservoir maintained at greater than about 40% filled.

20. A method according to claim 12, further comprising the step of:

(f) selectively coupling at least one of said diluent and solution transport paths to a waste container.

21. A method according to claim 12, wherein step (b) comprises varying the orientation of said component storage container so as to enable substantially the entire contents of said component storage container to be extracted and delivered by said fluid component transport path to said solution mixing container.