Apparatus for producing liquid mixture having predetermined concentration of a specific component

• US 6,290,384 B1
• Filed: 01/06/2000
• Issued: 09/18/2001
• Est. Priority Date: 11/24/1998
• Status: Expired due to Term

• Current Assignee: Air Liquide Electronics US LP (Air Liquide SA)
• Original Assignee: BOC Group Pty Limited (Linde Plc)
• Inventors: Jansen, Frank, Pozniak, Peter M., Roberts, Benjamin R.
• Primary Examiner(s): Cooley, Charles E.
• Application Number:
  US09/479,290
• Time in Patent Office: 621 Days
• Field of Search: 366/132, 366/134, 366/136, 366/137, 366/142, 366/152.1, 366/152.4, 366/152.6, 366/153.1, 366/160--16, 366/160.5, 366/182.1, 366/182.2, 366/191, 366/192, 366/336-340, 137/3, 137/5, 137/93, 137/563
• US Class Current: 366/136
• CPC Class Codes: B01F 23/405 Methods of mixing liquids with liquids B01F23/4105 takes precedence
• CPC Class Codes: B01F 35/80 Forming a predetermined ratio of the substances to be mixed controlling ratio of two or more flows of fluid or fluent material G05D11/02
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: G05D 11/138 by sensing the concentration of the mixture, e.g. measuring pH value
• CPC Class Codes: Y10T 137/034 Controlled by conductivity of mixture

Abstract

A method and apparatus for producing a liquid mixture in which mixture components are mixed to produce a product stream having a predetermined connection of a specified component. This mixing occurs within a fluidic network designed such that the components mix in inlet branches to form a first intermediate mixture having a lower concentration than that desired in the product stream. The specified component is metered into the intermediate product stream to produce a second intermediate product stream that is blended to produce a third intermediate product stream. The concentration of the specified component within the third intermediate product stream is measured and the metering pump is appropriately adjusted. The third intermediate product stream then passes through a recycle loop in which recycled product is mixed with an intermediate product stream to produce a liquid mixture stream that is divided into the recycle stream and a product stream.

Claims

1. An apparatus for producing a product stream having a liquid mixture with a predetermined concentration of a specified component, said apparatus comprising:

a fluidic network, comprising;

two inlet branches in flow communication to mix component streams, at least one of said inlet branches containing said specified component to form a first intermediate mixture stream having a lower concentration of said specified component than said predetermined concentration;

remotely activated cut-off valves within said inlet branches of said fluidic network, said cut-off valves being operable to assume open and closed positions;

an intermediate branch having an inlet to introduce a stream of said specified component into said first intermediate mixture stream to form a second intermediate mixture stream;

means for blending said second intermediate mixture stream to produce a third intermediate mixture stream; and

a recycle loop, comprising;

an inlet junction connected to said intermediate branch,

an outlet junction in flow communication with an outlet to discharge a product stream, and

a recycle leg communicating between said inlet junction and said outlet junction thereby to introduce a recycle stream into said third intermediate stream to form a liquid mixture stream, said liquid mixture stream dividing at said outlet junction to form said recycle stream and said product stream thereby continually recycling a part of said liquid mixture stream into said third intermediate stream while the product stream is being discharged;

a pump located within said recycle loop to pump said liquid mixture stream;

a pressure vessel in communication with said pump;

means for sensing the liquid level within said pressure vessel;

a controller responsive to said liquid level sensing means, said controller connected to said remotely activated cut-off valves and adapted to control said valves to be open when the liquid level in said pressure vessel rises to a high level;

means for measuring the concentration of said specified component within said third intermediate mixture stream; and

means for metering said introduction of said stream of said specified component into said first intermediate mixture stream so that said third intermediate mixture stream contains said specified component in said predetermined concentration.

2. The apparatus in accordance with claim 1, further comprising:

a reservoir for said specified component stream, wherein said metering means comprises;

a metering pump connected to said inlet of said intermediate branch to pump said specified component stream from said reservoir into said first intermediate mixture stream, and

another controller responsive to said third intermediate mixture stream specified component concentration measuring means to control said metering pump so that the concentration of said specified component within said third intermediate mixture stream is about said predetermined concentration.

3. The apparatus in accordance with claim 2, wherein said measuring means for said third intermediate mixture stream specified component concentration comprises:

a conductivity sensor; and

said second intermediate mixture stream blending means comprises;

a static mixer for blending said second intermediate mixture stream.

4. The apparatus in accordance with claim 1, wherein said measuring means for said third intermediate mixture stream specified component concentration comprises:

a conductivity sensor; and

said second intermediate mixture stream blending means comprises;

a static mixer for blending said second intermediate mixture stream.

5. The apparatus for producing a product stream having a liquid mixture with a predetermined concentration of a specified component, said apparatus comprising:

a fluidic network, comprising;

two inlet branches in flow communication to mix component streams, at least one of said inlet branches containing said specified component to form a first intermediate mixture stream having a lower concentration of said specified component than said predetermined concentration;

an intermediate branch having an inlet to introduce a stream of said specified component into said first intermediate mixture stream to form a second intermediate mixture stream;

means for blending said second intermediate mixture stream to produce a third intermediate mixture stream;

a recycle loop comprising;

an inlet junction connected to said intermediate branch,

an outlet junction in flow communication with an outlet to discharge a product stream, and

a recycle leg communicating between said inlet junction and said outlet junction thereby to introduce a recycle stream into said third intermediate stream to form a liquid mixture stream, said liquid mixture stream dividing at said outlet junction to form said recycle stream and said product stream thereby continually recycling a part of said liquid mixture stream into said third intermediate stream while the product stream is being discharged;

means for measuring the concentration of said specified component within said third intermediate mixture stream;

means for metering said introduction of said stream of said specified component into said first intermediate mixture stream so that said third intermediate mixture stream contains said specified component in said predetermined concentration;

a reservoir for said specified component stream;

wherein said specified component metering means comprises;

a metering pump connected to said inlet of said intermediate branch to pump said specified component stream from said reservoir into said first intermediate mixture stream, and

a controller responsive to said third intermediate mixture stream specified component concentration measuring means to control said metering pump so that the concentration of said specified component within said third intermediate mixture stream is about said predetermined concentration.

6. The apparatus in accordance with claim 5, further comprising:

remotely activated cut-off valves within said inlet branches of said fluidic network, said cut-off valves being operable to assume open and closed positions;

a pump located within said recycle loop to pump said liquid mixture stream;

a pressure vessel in communication with said pump;

means for sensing the liquid level within said pressure vessel; and

a controller responsive to said liquid level sensing means, said controller connected to said remotely activated cut-off valves and configured to control said valves such that they assume the open position when the liquid level in said pressure vessel rises to a high level.

7. The apparatus in accordance with claim 6, wherein said third intermediate mixture stream specified component concentration measuring means comprises:

a conductivity sensor; and

said second intermediate mixture steam blending means comprises;

a static mixture.

8. The apparatus in accordance with claim 5, wherein said measuring means for said third intermediate mixture stream specified component concentration comprises:

a conductivity sensor; and

said second intermediate mixture stream blending means comprises;

a static mixer for blending said second intermediate mixture stream.