Heater with removable cartridge

• US 6,512,212 B1
• Filed: 10/30/2000
• Issued: 01/28/2003
• Est. Priority Date: 10/30/2000
• Status: Expired due to Fees

• Current Assignee: The Thermomedics International Incorporated
• Original Assignee: The Thermomedics International Incorporated
• Inventors: Leverne Harris, J. C.
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): VAN, QUANG T
• Application Number:
  US09/702,031
• Time in Patent Office: 820 Days
• Field of Search: 219/628, 219/629, 219/630, 219/635, 219/602, 392/470, 392/465, 392/477, 392/493, 428/35.7, 428/36.91, 428/35.9
• US Class Current: 219/628
• CPC Class Codes: A61M 2205/368 by electromagnetic radiation, e.g. IR waves
• CPC Class Codes: A61M 5/44 having means for cooling or heating the devices or media

Abstract

A heater device that is particularly adapted for use in supplying fluids to a living entity, such as a human or an animal. The heater is a transformer and includes a core, a primary winding and a secondary. The core is preferably a pair of E-shaped core sections, each having outer legs and an inner leg, with the outer legs being longer than the inner legs. The core thus forms a receiver opening intermediate the inner legs that slidingly receives a self-contained cartridge enclosing the secondary. The secondary is a planar, tubular conduit shaped in the configuration of an elongated loop and having an inlet for receiving fluid and an outlet for discharging that fluid at an elevated temperature. The extending ends of the outer and inner legs of each core sections face each other and form a receiver opening intermediate the inner legs. The cartridge is insertable and removable from the opening. When inserted, the secondary is in the magnetic flux created by an alternating power supplied to the primary windings and the secondary is shorted out to convert that magnetic flux into heat to warm the fluid passing through the secondary to the desired temperature. The cartridge is easily removable for cleaning and/or replacement.

Claims

1. A heater for warming a fluid, said heater comprising:

a transformer, said transformer having a core, a primary winding associated with said core and adapted to generate an alternating magnetic field in the presence of an alternating power passing through said primary winding and a secondary winding,

a secondary cartridge interfitted into said core, said secondary cartridge enclosing the secondary winding comprising a metallic conduit having an inlet and an outlet for passing a fluid through said secondary cartridge, said secondary cartridge, when interfitted into said core, being located in the alternating magnetic field to produce induced currents in said secondary winding, said secondary winding being shorted out to convert the induced currents into heat to heat a fluid passing therethrough,

wherein said secondary cartridge is readily removed from the interfitting relationship with said core.

2. The heater as defined in claim 1 wherein said core has an opening therein and said secondary cartridge interfits into said opening.

3. The heater as defined in claim 1 wherein said secondary cartridge comprises a housing having said metallic conduit embedded therein.

4. The heater as defined in claim 3 wherein said metallic conduit comprises an elongated loop configuration wherein said elongated loop is electrically connected to create an electrical short at about said inlet and said outlet.

5. The heater as defined in claim 3 wherein said metallic conduit has an internal surface coated with a lubricious film.

6. The heater as defined in claim 5 wherein said metallic conduit has an internal surface coated with parylene.

7. The heater as defined in claim 3 wherein said heater has at least one temperature sensor affixed with respect to said core, said at least one temperature sensor adapted to directed energy toward said metallic conduit and to receive energy reflected therefrom to sense the temperature of at least one area of said conduit.

8. The heater as defined in claim 7 wherein said heater has three temperature sensors adapted, respectively, to direct the energy toward and receive reflected energy from areas of said conduit near said inlet, near said outlet and about an area equidistant between said inlet and said outlet.

9. A transformer secondary cartridge for removably interfitting with a transformer core having a primary winding, said transformer secondary cartridge comprising a housing, a conduit contained within said housing and being comprised at least partially of an electrical conducting material, said conduit having an inlet and an outlet for supplying a fluid to and for receiving fluid from said conduit, said conduit forming an elongated, generally planar loop and being shorted out near said inlet and said outlet whereby said transformer secondary cartridge is self-contained and is readily attachable and detachable from a transformer core having a primary.

10. The transformer secondary cartridge as defined in claim 9 wherein said conduit is a tubular thin-walled ferrous material.

11. The transformer secondary cartridge as defined in claim 10 wherein said tubular thin-walled ferrous conduit is stainless steel having a wall thickness of about 0.004 to 0.006 inches.

12. The transformer secondary cartridge as defined in claim 9 wherein said conduit is embedded in said housing.

13. The transformer secondary as defined in claim 9 wherein said conduit has an internal surface coated with a lubricious film.

14. The transformer secondary as defined in claim 13 wherein said lubricious film is parylene.

15. The transformer secondary as defined in claim 9 wherein said elongated, generally planar loop of said secondary comprises a loop having a plurality of abrupt curves in excess of 45 degrees.

16. The transformer secondary as defined in claim 15 wherein said elongated loop has at least 6 abrupt curves.

17. The transformer secondary as defined in claim 15 wherein each of said abrupt curves comprises an expanded diameter between an entrance to an abrupt curve and an end point of the abrupt curve.

18. A heater for warming a fluid, said heater comprising:

a pair of E-shaped transformer core sections, each of said E-shaped core sections having outer legs and an inner leg, said inner leg of each of said core sections being shorter in length that said outer legs, a primary winding wound around each of said core sections, said core sections being positioned such that said outer legs of one of said core section is located contiguous to the outer legs of said other core section, each of said primary windings adapted to generate an alternating magnetic field in the presence of an alternating power passing through each of said primary windings, said pair of primary windings being enclosed with a potting material and forming a receiver opening intermediate said inner legs of said core sections,

a secondary cartridge interfitted into said receiver opening, said secondary cartridge including a thin-walled, metallic conduit having an inlet and an outlet for passing a fluid through said secondary cartridge, said secondary cartridge, when interfitted into said receiver opening, being located in the alternating magnetic field to produce induced currents in said metallic conduit, said thin-walled metallic conduit acting as a secondary winding to said primary winding and being shorted out to convert the induced currents into heat to heat the fluid passing therethrough, said secondary cartridge being readily removed and reinserted into said receiver opening.

19. The heater for warming a fluid as defined in claim 18 wherein said secondary cartridge is comprised of a plastic material enclosing said thin-walled metallic conduit.

20. The heater for warming a fluid as defined in claim 18 wherein said thin-walled metallic conduit is formed in the configuration of an elongated loop.

21. The heater for warming a fluid as defined in claim 18 wherein said thin-walled metallic conduit has an interior surface coated with a film of a lubricious material.

22. The heater for warming a fluid as defined in claim 18 wherein said plastic material is a glass filled polyetheramide composition.

23. The heater for warming a fluid as defined in claim 18 wherein said metallic conduit is a stainless steel conduit having a wall thickness of about 0.004 to 0.006 inches.

24. The heater for warming a fluid as defined in claim 18 wherein said metallic conduit is a planar, elongated loop having a plurality of abrupt curves.

25. The heater for warming a fluid as defined in claim 24 wherein said thin-walled metallic conduit has a predetermined diameter and wherein said abrupt curves have an increased diameter with respect to said predetermined diameter.

26. The heater for warming a fluid as defined in claim 18 wherein said secondary winding is shorted out by means of a weld joining said elongated loop together at a point near said inlet and said outlet.

27. The heater for warming a fluid as defined in claim 26 wherein said weld has a weld area and said weld area is at least 2 times the cross sectional area of said metallic conduit.

28. The heater for warming a fluid as defined in claim 19 wherein said heater includes at least one temperature sensor in a potting material, said at least one temperature sensor being adapted to sense the temperature of at least one area of said metallic conduit.

29. The heater for warming a fluid as defined in claim 28 wherein said at least one temperature sensor comprises three temperature sensors adapted to sense, respectively, the temperature of said thin-walled metallic conduit at an area near said inlet, an area near said outlet and an area about equidistant between said inlet and said outlet.

30. The heater for warming a fluid as defined in claim 28 wherein said at least one area of said conduit comprises at least one blackened area of the external surface of said conduit.

31. The heater for warming a fluid as defined in claim 30 wherein said temperature sensor is an infrared sensor and said plastic material surrounding said secondary has at least one opening corresponding to said at least one blackened area to allow infrared energy from said temperature sensor to impinge upon and be reflected from said at least one blackened area.

32. The heater for warming a fluid as defined in claim 30 wherein said at least one area of said conduit comprises three areas located at, respectively, near said inlet, near said outlet and about equidistant between said inlet and said outlet.

33. The heater for warming a fluid as defined in claim 19 further including a pair of transition blocks comprised of a low magnetic permeability material located in contact with and spanning the lateral external surfaces of said core sections.