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EP-4251862-B1 - ELECTRICALLY POWERED CATALYST HEATER FOR FLUID TREATMENT SYSTEMS

EP4251862B1EP 4251862 B1EP4251862 B1EP 4251862B1EP-4251862-B1

Inventors

  • COLLINS, THOMAS ADAM
  • HEINE, David Robert
  • SHINDE, Avinash Tukaram

Dates

Publication Date
20260506
Application Date
20211122

Claims (14)

  1. A heater assembly (10) comprising: a heater body (12) comprising a monolithic honeycomb structure comprising a plurality of intersecting walls (16), wherein the walls (16) have a thickness (t) and extend in an axial direction (Z) to form a plurality of cells (18) of the honeycomb structure that extend axially from a first end face (24a; 24") to a second end face (24b; 24"); a first electrode (14) coupled to the heater body (12); a second electrode (14) coupled to the heater body (12), wherein a current-carrying path (22) is defined over the walls (16) between the first electrode (14) and the second electrode (14); and a plurality of openings (26) that extend through the thickness (t) of at least some of the walls (16); characterized in that the openings (26) comprise a shape having a larger flow area in a downstream axial half proximate to a downstream side (30) of the shape than in an upstream axial half proximate to an upstream side (32) of the shape.
  2. The heater assembly (10) of claim 1, further comprising a plurality of insulating slots (20) that each extend laterally across at least a portion the heater body (12) and disrupt the current-carrying path (22).
  3. The heater assembly of any one of claims 1-2, wherein the openings (26) comprise a shape having a downstream side (30) and an upstream side (32), relative to a flow of gas (25) through the heater body (12), wherein a first lateral dimension (W1) of the downstream side (30) is wider than a second lateral dimension (W2) of the upstream side (32), wherein the specific lateral dimensions are measured at the axial extremes of the upstream and downstream edges of its shape.
  4. The heater assembly of claim 1, wherein the openings (26) each comprise a shape having a tapered end and the tapered end is at an upstream side (32) of the shape, relative to a flow of gas (25) through the heater body (12), wherein a maximum lateral dimension is located in a downstream axial half of the shape, which then tapers in an upstream axial half of the shape.
  5. The heater assembly (10) of any one of claims 1-4, wherein each cell (18) is enclosed by a plurality of segments (28) of the intersecting walls (16), and wherein the heater body (12) comprises a plurality of the openings (26) in at least some of the segments (28) of the walls (16) that enclose each of the cells (18).
  6. The heater assembly (10) of claim 5, wherein at least some of the segments (28) comprise a row of at least two of the openings (26), or wherein at least some of the segments (28) comprise a column of the openings (26) axially-spaced along the segment (28), or wherein at least some of the segments (28) comprise an array of the openings (26) and the array comprises a plurality of rows and a plurality of columns.
  7. The heater assembly (10) of any one of claims 1-6, wherein at least a subset of the cells (18) are enclosed by a plurality of segments (28) of the intersecting walls (16), wherein the plurality of segments (28) for each cell (18) comprises at least a first wall segment and a second wall segment, wherein both of the first wall segment and the second wall segment each comprise at least one of the openings (26), and wherein the at least one (26) opening in the first wall segment is not axially aligned with any of the openings (26) in the second wall segment.
  8. The heater assembly (10) of claim 7, wherein the at least one opening (26) in the first wall segment comprises a first set of openings (26) that are axially-spaced from each other along the first wall segment, wherein the at least one opening (26) in the second wall segment comprises a second set of openings (26) that are axially-spaced from each other along the second wall segment, and wherein the first set of openings (26) are axially aligned with respect to the second set of openings (26).
  9. The heater assembly (10) of claim 7, wherein the at least one opening (26) in the first wall segment comprises a first set of openings (26) that are axially-spaced from each other along the first wall segment, wherein the at least one opening (26) in the second wall segment comprises a second set of openings (26) that are axially-spaced from each other along the second wall segment, and wherein the first set of openings (26) are axially offset with respect to the second set of openings (26).
  10. The heater assembly (10) of any of claims 7-9, wherein a cross-sectional shape of the cells (18) in the subset of cells (18) is rectangular, and the first wall segment and the second wall segment are oppositely disposed sides.
  11. The heater assembly (10) of any of claims 1-10, wherein a first axial distance (d3) between at least a first adjacent pair of axially-spaced openings (26) is not equal to a second axial distance (d4) between at least a second adjacent pair of axially-spaced openings (26).
  12. An exhaust aftertreatment system (100) comprising the heater assembly (10) of any one of claims 1-11 and a catalyst substrate or particulate filter in fluid communication with each other.
  13. A method of treating a fluid with the fluid treatment system (100) of claim 12, comprising: applying a voltage potential across the electrodes (14) of the heater assembly (10) to generate heat in the heater body (12) as a result of current flowing through the current-carrying path (22) between the electrodes (14); heating a gas flow (25) with the heat generated by the heater body (12) to increase a temperature of the gas flow (25); and then heating a ceramic honeycomb body with the gas flow (25).
  14. A method of manufacturing a monolithic heater body (12) for a heater assembly (10) of any one of claims 1-11, the method comprising: forming the plurality of intersecting walls (16), wherein the walls (16) have a thickness (t) and extend in the axial direction (Z) to form the plurality of cells (18) of a honeycomb structure that extend axially from the first end face (24a) to the second end face (24b); and forming the plurality of openings (26) that extend through the thickness (t) of at least some of the walls (16).

Description

BACKGROUND This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Serial No. 63/119029 filed on November 30, 2020. 1. Field This disclosure relates to fluid treatment systems, such as exhaust aftertreatment systems, and more particularly heater assemblies to aid in the treatment of fluids, such as electrically powered heaters useful for activating catalysts in exhaust aftertreatment systems. 2. Technical Background Some fluid treatment systems, such as engine exhaust aftertreatment systems, may benefit from additional heat supplied from a supplemental heater. Examples of such systems include electrically heated catalyst (EHC) systems that have an electrically powered heater useful to quickly achieve temperatures sufficient to initiate activation of a catalyst material in the aftertreatment of engine exhaust. US 5 514 347 A discloses a heater assembly showing the features of the preamble of claim 1. US 5 436 216 A, WO2007/010985 A1 and EP 0 661 421 B1 show additional prior art. SUMMARY The invention provides a heater assembly according to claim 1. In some embodiments, the heater assembly further comprises a plurality of insulating slots that each extend laterally across at least a portion the heater body and disrupt the current-carrying path. In some embodiments, the insulating slots are formed by an absence of the intersecting walls along the slots. In some embodiments, the tapered end is triangular, trapezoidal, semi-circular, or semi-ellipsoidal. In some embodiments, the shape is pentagonal. In some embodiments, the channels have a cross-sectional shape enclosed by a plurality of web portions of the walls, each web portion extending between intersections between the walls. In some embodiments, a cross-sectional shape of the cells is square. In some embodiments, each cell is enclosed by a plurality of segments of the intersecting walls, and wherein the heater body comprises at least one of the openings in each segment of the walls. In some embodiments, each cell is enclosed by a plurality of segments of the intersecting walls, and wherein the heater body comprises a plurality of the openings in at least some of the segments of the walls that enclose each of the cells. In some embodiments, at least some of the segments comprise a row of at least two of the openings. In some embodiments, at least some of the segments comprise a column of the openings axially-spaced along the segment. In some embodiments, at least some of the segments comprise an array of the openings, wherein the array comprises a plurality of rows and a plurality of columns. In some embodiments, at least a subset of the cells are enclosed by a plurality of segments of the intersecting walls, wherein the plurality of segments for each cell comprises at least a first wall segment and a second wall segment, wherein both of the first wall segment and the second wall segment each comprise at least one of the openings, and wherein the at least one opening in the first wall segment is not axially aligned with any of the openings in the second wall segment. In some embodiments, the at least one opening in the first wall segment comprises a first set of openings that are axially-spaced from each other along the first wall segment, wherein the at least one opening in the second wall segment comprises a second set of openings that are axially-spaced from each other along the second wall segment, and wherein the first set of openings are axially aligned with respect to the second set of openings. In some embodiments, the at least one opening in the first wall segment comprises a first set of openings that are axially-spaced from each other along the first wall segment, wherein the at least one opening in the second wall segment comprises a second set of openings that are axially-spaced from each other along the second wall segment, and wherein the first set of openings are axially offset with respect to the second set of openings. In some embodiments, a cross-sectional shape of the cells in the subset of cells is rectangular, and the first wall segment and the second wall segment are oppositely disposed sides. In some embodiments, a first axial distance between at least a first adjacent pair of axially-spaced openings is not equal to a second axial distance between at least a second adjacent pair of axially-spaced openings. In some embodiments, the heater body is arranged as a disc. In some embodiments, a fluid treatment system comprises the heater assembly of any one of the preceding paragraphs and a ceramic honeycomb body in fluid communication with each other. In some embodiments, the ceramic honeycomb body is arranged as a catalyst substrate or a particulate filter. In some embodiments, the fluid treatment system is an exhaust aftertreatment system. In some embodiments, a method of treating a fluid with the fluid treatment system of any of the preceding paragraphs comprises applying a voltage potential