Electric air-heater unit utilizing a centrifugal impeller

{
  "publication_number": "US4090061A",
  "country": "US",
  "kind": "A",
  "title": "Electric air-heater unit utilizing a centrifugal impeller",
  "abstract": "An air heating unit comprises a blower casing, a centrifugal impeller and a heating element in the shape of a cylindrical cage of longitudinal guide vanes fastened to the wall of the casing. The guide vanes are made from an electric resistance alloy in sheet form in the shape of uniform strips of a length conforming to the width of the impeller, all vanes being connected at their ends by conductive bridging pieces jointing the alternate ends of each two proximate vanes, thus forming a resister in zigzag pattern provided with terminals for energizing it. The vanes and the bridging pieces may form part of a single rectangular sheet rolled up to form the cylindrical casing and provided with alternate transverse cuts along both edges which stop short of the bridging pieces. The strips between the bridging pieces are bent or curved outwardly from the sheet at a desired angle.",
  "claims": [
    "1. An apparatus for heating and delivering air comprising a bladed, centrifugal impeller rotatable about an axis and an electric heating element in the shape of a stationary cylindrical cage of spaced longitudinal air guide vanes made of an electric resistance alloy, said cage being substantially coextensive in height with the width of the impeller and being positioned so as to surround said impeller in peripheral, spaced concentric alignment, said guide vanes being in the shape of strips of uniform width extending substantially parallel to the longitudinal axis of the cage, the surface of each strip being inclined in respect of the ideal cylindrical surface of the cage, the inclination being uniform in degree and direction for all strips of the cage, means being provided for electrically energizing the said guide vanes for heating said vanes to a temperature adequate for heating the air passing through the impeller and the guide vanes and means for rotating the impeller to cause air to flow through the air guide vanes of the cage.",
    "2. An apparatus for heating and delivering air as defined in claim 1, wherein said centrifugal impeller and said cylindrical cage are at least partly enclosed in casing means provided with openings for the inlet and discharge of air, said cylindrical cage being supported in said casing means in concentric alignment with the centrifugal impeller by engagement of at least one end of said cage with the walls of said casing means.",
    "3. An apparatus for heating and delivering air as defined in claim 2, wherein said casing means is in the shape of a blower housing with opposed circular grooves provided in its side walls for insertion therein of the two opposite ends of the cylindrical cage.",
    "4. An apparatus for heating and delivering air as defined in claim 1, wherein said cylindrical cage is formed from an electric resistance alloy sheet and said guide vanes are in the shape of uniform strips of a length substantially commensurate with the width of said impeller and curved in a direction perpendicular to their long axis, said guide vanes being held in a predetermined angle of incidence by conductive bridging pieces jointing the alternate ends of each two proximate vanes of the cage, so as to form a resistor circuit in zigzag pattern, said means for electrically energizing said guide vanes comprising at least two terminals being provided on the heating element for supplying electric current to the resistor circuit.",
    "5. An apparatus for heating and delivering air as defined in claim 4, wherein said bridging pieces and said guide vanes are integrally formed from a single sheet of resistance alloy material.",
    "6. An appratus apparatus for heating and delivering air, as defined in claim 1, wherein said means for electrically energizing said guide vanes comprises at least three electric terminals spaced over the circumference of the cylindrical cage."
  ],
  "cpc": [
    "F24H 3/0405"
  ],
  "assignees": [
    "GLUCKSMAN DOV ZEEV"
  ],
  "filing_date": "1976-03-01",
  "publication_date": "1978-05-16",
  "grant_date": "1978-05-16",
  "priority_date": "1975-03-09",
  "application_number": "US-66280776-A",
  "family_id": "11048110",
  "citations": [
    "US1928142A",
    "US1975410A",
    "US2102302A",
    "US2133188A",
    "US2424780A",
    "US2474664A",
    "US2553875A",
    "US2702332A",
    "US2790889A",
    "US3211891A"
  ]
}