High power density insulated exhaust heating system

Patent metadata

Field	Value
Publication number	US-2020200060-A1
Application number	US-202016806175-A
Country	US
Kind code	A1
Filing date	Mar 2, 2020
Priority date	Oct 31, 2016
Publication date	Jun 25, 2020
Grant date	—

Abstract

A heating apparatus for a fluid flow system having a fluid conduit includes at least one heater element and a support member within the conduit. The at least one heater element includes a resistance wire, a sheath, and an electrically insulating material. The sheath has a closed profile shape that extends along a tortuous path through the container body and surrounds the resistance wire along the tortuous path. The insulating material is disposed about the wire between the wire and the sheath. The support member restricts movement of the at least one heater element relative to the fluid conduit. The support member defines a corrugated geometry that follows the tortuous path while contacting the sheath along a majority of a length of the sheath. The support member increases heat transfer from the at least one heater element to a fluid flowing through the fluid conduit.

First claim

What is claimed is:

1 . A heating apparatus for an exhaust gas system having a container body, the heating apparatus comprising:
at least one heater element within the container body, the at least one heater element including a resistance wire, a sheath, and an insulating material, the sheath having a closed profile shape that extends along a spiral path through the container body and surrounds the resistance wire along the spiral path, the insulating material disposed about the resistance wire between the resistance wire and the sheath; and a support member disposed inside the container body and configured for restricting movement of the at least one heater element in the container body, the support member including a strip that defines a tortuous geometry that follows the spiral path while contacting the sheath along a majority of a length of the sheath, wherein the insulating material electrically insulates the resistance wire from the sheath, wherein the support member increases heat transfer from the at least one heater element to an exhaust gas flowing through the container body.

2 . The heating apparatus according to claim 1 , wherein the at least one heater element is sandwiched between portions of the strip that are located at different locations along the spiral shape of the strip.

3 . The heating apparatus according to claim 1 , wherein the strip is a corrugated strip defining a plurality of ridges and grooves.

4 . The heating apparatus according to claim 3 , wherein the corrugated strip further defines a plurality of indentations disposed at the ridges and grooves and the sheath is received in the indentations.

5 . The heating apparatus according to claim 1 , wherein the support member further includes an outer peripheral wall surrounding the strip.

6 . The heating apparatus according to claim 5 , wherein the outer peripheral wall defines at least one annular groove.

7 . The heating apparatus according to claim 5 , wherein the outer peripheral wall defines an outer boundary of an exhaust gas flow channel through the container body.

8 . The heating apparatus according to claim 5 , wherein the container body defines an outer boundary of an exhaust gas flow channel and the outer peripheral wall is a separate component from the container body and is disposed inside the container body.

9 . The heating apparatus according to claim 5 , wherein the outer peripheral wall is fixed to the strip.

10 . The heating apparatus according to claim 1 , wherein the strip is fixed to the at least one heater element at a plurality of contact points, the plurality of contact points being spaced at a spacing along a length of the strip, the spacing is less than ten times an outside diameter of the at least one heater element.

11 . The heating apparatus according to claim 10 , wherein a natural frequency of vibration for sections of the at least one heater element between adjacent two of the contacts points is greater than 400 Hz.

12 . The heating apparatus according to claim 10 , wherein the number of contact points is selected such that a temperature variation across the heating apparatus is less than 200° C.

13 . The heating apparatus according to claim 1 , wherein the at least one heating element has a power density greater than 84 watts/in 2 for the sheath.

14 . A heating apparatus for a fluid flow system having a fluid conduit, the heating apparatus comprising:
at least one heater element within the fluid conduit, the at least one heater element including a resistance wire, a sheath, and an insulating material, the sheath having a closed profile shape that extends along a tortuous path through the container body and surrounds the resistance wire along the tortuous path, the insulating material disposed about the resistance wire between the resistance wire and the sheath; and a support member disposed within the fluid conduit and configured for restricting movement of the at least one heater element relative to the fluid conduit, the support member defining a corrugated geometry that follows the tortuous path while contacting the sheath along a majority of a length of the sheath, wherein the insulating material electrically insulates the resistance wire from the sheath, wherein the support member increases heat transfer from the at least one heater element to a fluid flowing through the fluid conduit.

15 . The heating apparatus according to claim 14 , wherein the support member includes a strip that defines the corrugated geometry.

16 . The heating apparatus according to claim 14 , wherein the corrugated shape includes a plurality of ridges and grooves and the strip defines a plurality of indentions disposed at the ridges and grooves, the sheath being received in the indentions.

17 . The heating apparatus according to claim 14 , wherein the support member includes a peripheral wall that defines an outer boundary of a gas flow channel of the fluid conduit.

18 . A heating apparatus for a fluid flow system having a fluid conduit, the heating apparatus comprising:
at least one heater element extending along a tortuous path within the fluid conduit, the at least one heater element including a resistance wire and an insulating material disposed about the resistance wire; and a continuous support member disposed within the fluid conduit and configured for restricting movement of the at least one heater element relative to the fluid conduit, the support member defining a tortuous geometry and following the tortuous path such that one side of a region of the heater element contacts a first location on the support member and an opposite side of the region of the heater element is flanked by a second location on the support member, the second location being further along the tortuous path than the first location, wherein the insulating material electrically insulates the resistance wire from the support member, wherein the support member increases heat transfer from the at least one heater element to a fluid flowing through the fluid conduit.

19 . The heating apparatus according to claim 18 , wherein the tortuous path is a spiral path.

20 . The heating apparatus according to claim 19 , wherein the support member includes a strip that defines the tortuous geometry and follows the spiral path.

Assignees

• Watlow Electric Mfg

Inventors

• Everly Mark D
• Ohse Jeremy
• Culbertson David P
• Williams Richard T
• Jambor George
• Wilson Jacob

Classifications

• H05B3/06

  Heater elements structurally combined with coupling elements or holders · CPC title

• H05B3/02

  Details · CPC title

• H05B3/00

  Ohmic-resistance heating · CPC title

• F01N2240/16

  an electric heater, i.e. a resistance heater · CPC title

• F01N3/2013 Primary

  using electric or magnetic heating means · CPC title