Electrochemical control valve

• US 5,038,821 A
• Filed: 08/06/1990
• Issued: 08/13/1991
• Est. Priority Date: 08/06/1990
• Status: Expired due to Term

• Current Assignee: Henri J.R. Maget
• Original Assignee: Henri J.R. Maget
• Inventors: Maget, Henri J. R.
• Primary Examiner(s): Cohan, Alan
• Application Number:
  US07/563,037
• Time in Patent Office: 372 Days
• Field of Search: 137/486, 137/487.5, 137/468, 251/11, 251/61, 251/129.01
• US Class Current: 137/486
• CPC Class Codes: F16K 31/025 actuated by thermo-electric means
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: Y10T 137/7759 Responsive to change in rate of fluid flow
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

An electrochemically actuated control valve is disclosed which represents a new class of devices for fluid flow control. The valve is activated by an electrochemical motor which converts DC electrical energy into compressed gas energy suitable for producing mechanical work. The mechanical motion is typically reciprocating linear motion. This linear displacement can be accurately controlled, can be modulated at high frequencies and responds quasi-instantaneously to the applied DC voltage. The electrochemical valve can be computer or microprocessor-controlled.

Claims

1. A control valve and actuator assembly comprising:

a gas-tight housing having two ends and a first wall at a first end;

flexible bellow means, disposed to form a second wall at a second end of said fluid-tight housing, having a first contacting surface;

a rigidly-supported electrolytic membrane having two sides disposed in said gas-tight housing and defining therein, with said first wall, a storage chamber for holding a supply of electrochemically active gas, and defining therein, with said flexible bellows means, a pump chamber;

one pervious electrode disposed on each said side of and in contact with said electrolytic membrane;

said electrode on a first said side of said electrolytic membrane and said electrode on a second said side of said electrolytic membrane being disposed to form one electrode pair separated by said electrolytic membrane;

said gas being electrochemically reversibly active so as to enter into an anodic reaction at one said electrode where the gas molecules are converted to ions transportable through said electrolytic membrane and a cathodic reaction at the opposite electrode in said electrode pair where said ions are reconverted to gas molecules;

a valve means having a second contacting surface disposed in contact with said first contacting surface adapted to open and close said valve means by moving forward and backward in response to motion of said flexible bellows means;

means for providing a reversible electric current to said electrode pair, said electric current acting to transport said ions through said electrolytic membrane whereby said gas is pumped reversibly from one side of said electrolytic membrane to the other;

pressure sensing means for sensing the pressure of said gas in said gas-tight pump chamber; and

control means, responsive to said pressure sensing means for varying the magnitude and direction of said electric current.

2. The apparatus of claim 1 wherein said pressure sensing means comprises an integrated electrochemical pressure sensor comprising at least one additional pair of electrodes disposed on opposite sides of said electrolytic membrane in electrical isolation from said pervious electrode pair.

3. The apparatus of claim 2 further comprising:

means for measuring the rate of fluid flow controlled by said valve; and

second control means, responsive to said flow rate sensing means, for varying the magnitude and direction of said electric current.

4. The apparatus of claim 2 further comprising:

temperature sensing means for sensing the gas temperature in said pump chamber; and

second control means, responsive to said temperature sensing means, for varying the magnitude and direction for said electric current.

5. The apparatus of claim 1 wherein said flexible bellows means comprises a flexible diaphragm.

6. Control valve and actuator assembly comprising:

a gas-tight housing having two ends and a first wall at a first end;

flexible bellows means, disposed to form a second wall at a second end of said fluid-tight housing, having a first contacting surface;

a rigidly-supported electrolytic membrane having two sides disposed in said gas-tight housing and defining therein, with said first wall, a storage chamber for holding a supply of electrochemically active gas, and defining therein, with said flexible bellows means, a pump chamber;

a plurality of pervious electrodes disposed on each said side of and in contact with said electrolytic membrane;

said plurality of electrodes on a first said side of said electrolytic membrane being separated from one another by spaces and said plurality of electrodes on a second said side of said electrolytic membrane being disposed to form, with said electrodes on said first side, a plurality of electrode pairs separated by said electrolytic membrane;

said gas being electrochemically reversibly active so as to enter into an anodic reaction at one said plurality of electrodes where the gas molecules are converted to ions transportable through said electrolytic membrane and a cathodic reaction at the opposite electrodes in said plurality of electrode pairs where said ions are reconverted to gas molecules;

a valve means having a second contacting surface disposed in contact with said first contacting surface adapted to open and close said valve means by moving forward and backward in response to motion of said flexible bellows means;

means for providing a reversible electric current to said plurality of electrode pairs, said electric current acting to transport said ions through said electrolytic membrane whereby said gas is pumped reversibly from one side of said electrolytic membrane to the other;

pressure sensing means for sensing the pressure of said gas in said gas-tight pump chamber; and

control means, responsive to said pressure sensing means for varying the magnitude and direction of said electric current.

7. The apparatus of claim 6 wherein said pressure sensing means comprises an integrated electrochemical pressure sensor comprising at least one additional pair of electrodes disposed on opposite sides of said electrolytic membrane in electrical isolation from said plurality of pervious electrode pairs.

8. The apparatus of claim 7 further comprising:

means for measuring the rate of fluid flow controlled by said valve; and

second control means, responsive to said flow rate sensing means, for varying the magnitude and direction of said electric current.

9. The apparatus of claim 7 further comprising:

temperature sensing means, for sensing the gas temperature in said pump chamber; and

second control means, responsive to said temperature sensing means for varying the magnitude and direction for said electric current.

10. The apparatus of claim 6 wherein said flexible bellows means comprises a flexible diaphragm.