Vortex gas elimination device

• US 5,707,431 A
• Filed: 12/18/1996
• Issued: 01/13/1998
• Est. Priority Date: 02/15/1994
• Status: Expired due to Term

• Current Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Original Assignee: Sims Level 1 Inc. (Smiths Group International Holdings Ltd.)
• Inventors: Ellsworth, James R., Sundstrom, Christina J., Verkaart, Wesley H.
• Primary Examiner(s): BUSHEY, CHARLES S
• Application Number:
  US08/767,199
• Time in Patent Office: 391 Days
• Field of Search: 55/320, 55/327, 55/337, 55/417, 55/459.1, 55/482, 55/498, 55/502, 96/177, 96/209, 96/212, 96/216, 96/219, 210/349, 210/430, 210/436, 210/453, 210/472, 210/512.1, 422/101
• US Class Current: 96/177
• CPC Class Codes: A61M 1/3623 Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 2206/16 Rotating swirling helical flow, e.g. by tangential inflows
• CPC Class Codes: A61M 5/40 using low-level float-valve to cut off media flow from reservoir position detection of a floating member A61M5/1685
• CPC Class Codes: B01D 2201/4084 Snap or Seeger ring connecting means

Abstract

A gas elimination device for cellular fluids has a cylindrical chamber that is divided radially into two parts by a cylindrical filter centrally located in the chamber. The fluid inlet is directed tangentially to the outer part of the chamber to create a vortex flow. The vortex flow is stopped by passage of the fluid through the filter, and gas bubbles that have formed rise to the top of the outer part of the chamber. A hydrophobic membrane covers the top of the chamber and allows the gas to exit the chamber to the atmosphere. A one way valve formed in a two part cap covering the chamber prevents flow of air into the chamber. A float valve stops flow when the chamber fills with air.

Claims

1. Apparatus for separating a gas from a fluid comprising a housing forming an elongate chamber, dividing means comprising a filter pervious to said fluid and said gas for dividing said chamber radially into outer and inner portions, inlet means for directing said fluid into said outer portion and for forming a vortex in said fluid in said outer portion, means for venting from said chamber gas that has been separated from said fluid, and outlet means for discharging said fluid from said inner portion wherein said outlet means comprises an elongate section having a fluid outlet and a float movable vertically in said elongate section for closing said outlet when said elongate section contains a predetermined amount of gas.

2. Apparatus according to claim 1 wherein said dividing means is positioned such that said fluid flows from said outer portion through said dividing means and into said inner portion and said dividing means substantially terminates vortex flow in said fluid.

3. Apparatus according to claim 1 wherein said means for venting comprises a hydrophobic membrane.

4. Apparatus according to claim 1 wherein said float comprises a tip that engages said fluid outlet to stop flow of said gas.

5. Apparatus according to claim 1 wherein said chamber comprises an upper cylindrical part aligned with said elongate section.

6. Apparatus according to claim 2 wherein said means for venting comprises one-way valve means for preventing the drawing of air into said chamber, said one-way valve means comprising a first part forming a valve seat and a second part made of flexible material and covering said seat, said second part having an outlet opening therein.

7. Apparatus for separating gas from a fluid comprising a housing forming a chamber, a filter extending axially along said chamber to divide said chamber radially into inner and outer portions, an inlet for supplying said fluid to the outer portion of said chamber and for forming a vortex in said fluid in said outer portion, means for supporting a hydrophobic membrane in communication with said chamber for allowing gas separated from said fluid to exit said apparatus, wherein said filter substantially stops vortex flow in said fluid as said fluid flows through said filter, and the downward velocity of fluid in said chamber is slower than the upward velocity of gas bubbles, whereby gas bubbles form in said fluid and gas exits through said hydrophobic membrane and further comprising outlet means for allowing said fluid to exit said chamber, said outlet means comprising an elongate section having a fluid outlet and a float movable vertically in said elongate section for closing said outlet when said elongate section contains a predetermined amount of gas.

8. Apparatus according to claim 7, wherein said filter includes separating means near the inlet for separating the filter from the sides of the chamber and sealing means for engaging an end portion of said chamber remote from said inlet and the transverse dimension of said seal is smaller than the transverse dimension of said separating means to facilitate insertion of said filter into said chamber.

9. Apparatus according to claim 8 wherein said chamber is cylindrical.

10. Apparatus for separating gas from a fluid comprising a housing forming a chamber, a filter extending axially along said chamber to divide said chamber radially into inner and outer portions, an inlet for supplying said fluid to the outer portion of said chamber and for forming a vortex in said fluid in said outer portion, means for supporting a hydrophobic membrane in communication with said chamber for allowing gas separated from said fluid to exit said apparatus, wherein said filter substantially stops vortex flow in said fluid as said fluid flows through said filter, and the downward velocity of fluid in said chamber is slower than the upward velocity of gas bubbles, whereby gas bubbles form in said fluid and gas exits through said hydrophobic membrane, wherein said means for supporting a hydrophobic membrane comprises a first part forming a valve seat and a second part made of flexible material covering said valve seat for engaging and sealing said valve seat, and wherein said second part comprises an outlet opening therein aligned with said valve seat for discharging gas that has passed through said hydrophobic membrane when said second part is displaced from said valve seat.

11. Apparatus according to claim 10 wherein said first and second parts form a one-way valve for allowing discharge of said gas when the pressure of said gas that has passed said hydrophobic membrane is greater than atmospheric pressure and preventing ingress of air when said pressure of said gas that has passed said hydrophobic membrane is less than atmospheric pressure.

12. Apparatus according to claim 11 wherein said second part is lifted from said seat to allow discharge of said gas when the pressure of said gas that has passed said hydrophobic membrane is greater than atmospheric pressure and said second part is held against said seat to prevent ingress of air when said pressure of said gas that has passed said hydrophobic membrane is less than atmospheric pressure.

13. Apparatus according to claim 12 wherein said first part comprises a relatively rigid structure having said hydrophobic membrane attached to a lower surface thereof, said valve seat extends upward from said lower surface, and said lower surface includes means surrounding said valve seat for allowing passage of said gas that has passed through said membrane to said valve seat.