Fluid flow control device
A flow control device that is uniquely capable of providing uniform flow under changing environmental conditions of temperature and pressure. The device achieves flow rate stabilization by taking advantage of the properties of the moving fluid in a channel with eddy currents that are generated as fluid moves past obstacles located in the fluid flow path. The shape and magnitude of such eddies depend on the viscosity of the fluid. Additionally, the device can also simultaneously stabilize the fluid flow rate under varying pressure by using a strategically positioned, yieldably deformable elastomeric membrane. Therefore, the invention uniquely combines two devices into one novel fluidic device that can stabilize a flow rate under simultaneously changing temperatures and pressures.
1. A flow control device comprising:
(a) a housing;
(b) a first fluid pathway formed in said housing, said first fluid pathway containing a fluid at a static pressure and having a first end having a fluid inlet and a second closed end;
(c) a second fluid pathway formed in said housing in communication with and located proximate said first fluid pathway, said second fluid pathway having a first end having a fluid inlet and a second end having a fluid outlet, said second fluid pathway containing a fluid flow;
(d) a yieldably deformable membrane disposed between said first and second fluid pathways; and
(e) flow rate stabilization means disposed within said second fluid pathway for achieving flow rate stabilization there within by providing viscosity dependent resistance to fluid flow along said fluid pathway, said means comprising an obstacle disposed within said second fluid pathway, said obstacle being constructed and arranged to produce an eddy within the fluid flowing along said second fluid pathway.
2. The device as defined in claim 1 in which said second fluid pathway contains a fluid flow having an inlet pressure at said fluid inlet and an outlet pressure at said fluid outlet and in which said yieldably deformable membrane is movable into said second fluid pathway when said outlet pressure at said fluid outlet of second fluid pathway is less than said inlet pressure at said fluid inlet of second fluid pathway.
3. The device as defined in claim 1 in which said obstacle comprises a stationary vane protruding into said second fluid pathway.
4. The device as defined in claim 2 in which said vane is constructed and arranged to produce an eddy within the fluid flowing along said second fluid pathway.
5. A flow control device comprising:
(a) a housing;
(b) a first fluid pathway formed in said housing, said first fluid pathway containing a fluid at a first pressure and having a first end having a fluid inlet and a second closed end;
(c) a second fluid pathway formed in said housing in communication with and located proximate said first fluid pathway, said second fluid pathway having a first end having a fluid inlet and a second end having a fluid outlet, said second fluid pathway containing a fluid flow having an inlet pressure at said fluid inlet and an outlet pressure at said fluid outlet;
(d) a yieldably deformable membrane disposed between said first and second fluid pathways, said yieldably deformable membrane being movable into said second fluid pathway when said outlet pressure at said fluid outlet of second fluid pathway is less than said inlet pressure at said fluid inlet of second fluid pathway; and
(e) flow rate stabilization means disposed within said second fluid pathway for achieving flow rate stabilization there within by providing viscosity dependent resistance to fluid flow along said fluid pathway, said means comprising an obstacle disposed within said second fluid pathway, said obstacle being constructed and arranged to produce an eddy within the fluid flowing along said second fluid pathway.
6. The device as defined in claim 5 in which said obstacle comprises a stationary vane protruding into said second fluid pathway.
7. The device as defined in claim 6 in which said vane is constructed and arranged to produce an eddy within the fluid flowing along said second fluid pathway.
8. The device as defined in claim 6 in which said second fluid pathway has a side wall and in which said obstacle comprises a vane affixed to said side wall and extending into said second fluid pathway.
9. The device as defined in claim 6 in which said second fluid pathway has a bottom wall and in which said obstacle comprises a vane affixed to said bottom wall and extending into said second fluid pathway.
10. The device as defined in claim 6 in which said second fluid pathway has a side wall and a bottom wall and in which said obstacle comprises a vane affixed to said side wall and said bottom wall and extending into said second fluid pathway.
11. The device as defined in claim 6 in which said vane has a length of between about 25 μm and about 1,000 μm.
12. The device as defined in claim 6 in which said vane has a thickness of between about 5 μm and about 100 μm.
13. A flow control device comprising:
(a) a housing;
(b) a first micro channel formed in said housing, said first micro channel containing a fluid at a first pressure and having a first end having a fluid inlet and a second closed end;
(c) a second micro channel formed in said housing in communication with and located proximate said first micro channel, said second micro channel having a first end having a fluid inlet and a second end having a fluid outlet, said second micro channel containing a fluid flow having an inlet pressure at said fluid inlet and an outlet pressure at said fluid outlet;
(d) a yieldably deformable membrane disposed between said first and second micro channels, said yieldably deformable membrane being movable into said second micro channel when said outlet pressure at said fluid outlet of second micro channel is less than said inlet pressure at said fluid inlet of second micro channel; and
(e) an obstacle disposed within said second micro channel for achieving flow rate stabilization there within by providing viscosity dependent resistance to fluid flow along said micro channel, said obstacle being constructed and arranged to produce an eddy within the fluid flowing along said second fluid pathway.
14. The device as defined in claim 13 in which said obstacle comprises a stationary vane protruding into said second micro channel.
15. The device as defined in claim 13 in which said vane has a length of between about 25 μm and about 1,000 μm.
16. The device as defined in claim 13 in which said vane has a thickness of between about 5·mu·m and about 100·mu·m.
17. The device as defined in claim 13 in which said first micro channel has a first segment of a first width, a second tapered segment and a third segment of a second width greater than said first width.
18. The device as defined in claim 17 in which said second micro channel has a first segment of a first width, a second tapered segment and a third segment of a second width greater than said first width.