Apparatus and method for controlling fluid flow

• US 20040046137A1
• Filed: 04/23/2003
• Published: 03/11/2004
• Est. Priority Date: 02/29/2000
• Status: Active Grant

• Current Assignee: Sloan Valve Company
• Original Assignee: Arichell Technologies Inc. (Sloan Valve Company)
• Inventors: Mo, Xiaoxiong, Parsons, Natan E., Herbert, Kay
• Granted Patent: US 6,948,697 B2
• Time in Patent Office: Days
• US Class Current: 251/129.04
• CPC Class Codes: F16K 31/0672 the valve member being a diaphragm
• CPC Class Codes: F16K 31/0675 Electromagnet aspects, e.g. electric supply therefor
• CPC Class Codes: F16K 31/082 using a electromagnet and a permanent magnet
• CPC Class Codes: F16K 37/00 Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given
• CPC Class Codes: F16K 37/0041 for measuring valve parameters F16K37/0033 takes precedence
• CPC Class Codes: Y10T 137/8242 Electrical

Abstract

An actuator base, bobbin, and pole piece form a pocket for an armature that a flexible membrane encloses to form an armature chamber filled with an incompressible fluid. The membrane protects the armature from exposure to corrosive fluids flowing in a conduit. Conduit flow can be stopped by driving the membrane against a valve seat. Pressure from the controlled fluid in the conduit is transmitted through the membrane to the fluid within the armature chamber so that the armature does not need to counteract force applied to the membrane by the conduit fluid'"'"'s pressure.

Claims

1. An electromagnetic actuator, comprising:

a solenoid coil and an armature housing constructed and arranged to form an armature pocket arranged to receive a ferromagnetic armature including a distal part, and

a membrane secured with respect to said pocket and arranged to enclose at least partially said distal part to seal armature fluid within said pocket, wherein displacement of said distal part displaces said membrane with respect to a valve passage controlled by said actuator.

2. The actuator of claim 1 further including a permanent magnet arranged to form a latching actuator.

3. The actuator of claim 2 further including a bias spring positioned and arranged to bias said armature toward its extended position.

4. The actuator of claim 1, 2 or 3 wherein said armature fluid includes incompressible fluid comprising corrosion inhibitor.

5. The actuator of claim 1, 2, or 3 wherein the incompressible fluid consists essentially of water mixed with a corrosion inhibitor.

6. The actuator of claim 1, 2, or 3 wherein said distal part of the armature is arranged to compress said membrane against a valve seat when said armature is disposed in its extended armature position.

7. The actuator of claim 6 wherein a ratio that the area of said distal part bears to the area of said membrane exposed to a conduit upstream of the membrane is between 1.4 and 12.3.

8. A method of operating an actuator of claim 1.

9. An actuator system comprising:

an actuator including an armature and a coil operable by application of a coil drive to displace said armature;

a membrane partially enclosing said armature;

an armature sensor constructed to detect displacement of said armature; and

a control circuit constructed to apply said coil drive to said coil in response to an output from said armature sensor.

10. An actuator system comprising:

a latching actuator including an armature and a coil operable by application of a coil drive thereto in a first drive direction to conduct current in a first current direction and thereby tend to drive said armature to a first end position;

a membrane partially enclosing said armature;

a sensor so coupled to the actuator as to sense said armature reaching said first end position; and

a control circuit operable to begin applying coil drive to said coil in said first drive direction and responsive to an output from said sensor meeting a predetermined first current-termination criterion to stop applying coil drive to the coil in the first drive direction.

11. The actuator of claim 10 wherein:

the coil is operable by application of a coil drive thereto in a second drive direction to conduct current in a second current direction and thereby tend to drive the armature to a second end position;

said sensor is so coupled to the actuator as to sense said armature reaching the second end position; and

said control circuit is operable to begin applying coil drive to the coil in the second drive direction and responsive to said sensor output meeting a predetermined second current-termination criterion to stop applying coil drive to said coil in the second drive direction.

12. The actuator of claim 11 wherein the first and second current-termination criteria differ.

13. The actuator of claim 9 or 10 wherein said sensor includes a piezoelectric transducer.

16. The actuator of claim 13 wherein:

said actuator system includes a housing that contains the armature and coil;

and said piezoelectric transducer is secured to the housing.

21. The system of claim 9 or 10 further including a motion sensor.

22. The system of claim 9 or 10 further including a presence sensor.

14. The actuator of claim 14 wherein, if the sensor output does not meet the first current-termination criterion within a predetermined first drive duration after the control circuit begins application of coil drive to the coil in the first drive direction, the control circuit applies coil drive to the coil in the first drive direction at a level higher than that at which it began application of coil drive to the coil.

15. The actuator of claim 14 wherein, if the sensor output does not meet the second current-termination criterion within a predetermined second drive duration after the control circuit begins application of coil drive to the coil in the second drive direction, the control circuit applies coil drive to the coil in the second drive direction at a level higher than that at which it began application of coil drive to the coil.

17. An actuator system comprising:

an actuator including an armature and a coil operable by application of a coil drive thereto in a first drive direction to conduct current in a first current direction and thereby tend to drive the armature to a first end position;

a membrane partially enclosing said armature;

an endpoint detector that detects the armature'"'"'s reaching the first end position and responds thereto by generating a detector output indicative thereof; and

a control circuit operable to begin application of coil drive to the coil in the first direction at a normal first-direction drive level and, if the detector output has not indicated within a predetermined first drive duration thereafter that the armature has reached the first end position, to apply coil drive to the coil in the first direction at an elevated first-direction drive level higher than the normal first-direction drive level.

18. A flow-control system comprising:

a valve operable between open and closed states;

a latching actuator including an armature operatively connected to the valve and further including a coil operable by application of a coil drive thereto in a first drive direction to conduct current in a first current direction and thereby tend to drive the armature to a first end position, in which the armature holds the valve in one of said open and closed states;

a membrane partially enclosing said armature;

an endpoint detector that detects the armature'"'"'s reaching the first end position and responds thereto by generating a detector output indicative thereof; and

a control circuit operable to begin application of coil drive to the coil in the first direction and responsive to the detector output indicative of the armature'"'"'s reaching the first end position to stop applying coil drive to the coil in the first drive direction.

19. The system of claim 18 wherein:

the flow-control system additionally includes an object sensor that produces an object sensor output; and

the control circuit'"'"'s application of the coil drive to the coil is dependent on the object-sensor output.

20. The system of claim 18 wherein:

the coil is operable by application of a coil drive thereto in a second drive direction to conduct current in a second current direction and thereby tend to drive the armature to a second end position, in which the armature holds the valve in the other of said open and closed states;

the endpoint detector detects the armature'"'"'s reaching the second end position and responds thereto by generating a detector output indicative thereof; and

the control circuit is operable to begin application of coil drive to the coil in the second direction at a normal first-direction drive level and responsive to the detector output indicative of the armature'"'"'s reaching the second end position to stop applying coil drive to the coil in the second drive direction.

23. For controlling an actuator including an armature and a coil operable by application of a coil drive thereto in a first drive direction to conduct current in a first current direction and thereby tend to drive the armature to a first end position, a method comprising:

applying coil drive to the coil in the first drive direction;

determining whether the armature has reached the first end position; and

if the armature has not reached the first end position within a predetermined first drive duration thereafter, applying coil drive to the coil in the first direction at an elevated first-direction drive level higher than the normal first-direction drive level.

24. The method of claim 23 wherein the actuator is a latching actuator.