초록

An archimedic or logarithmic scroll is used with an axial fan to provide a smooth and relatively quiet air flow over the electric heating elements. Additionally a lip 21 is mounted at the air outlet to prevent heated air from being drawn back through the axial fan.

대표청구항 ▼

A heating apparatus comprising a housing defining an air passageway and having a fan rotatably mounted therein for axially drawing air into said passageway, said housing having a scroll mounted therein, said scroll surrounding a portion of the fan and forming a part of the air passageway, said scrol

A heating apparatus comprising a housing defining an air passageway and having a fan rotatably mounted therein for axially drawing air into said passageway, said housing having a scroll mounted therein, said scroll surrounding a portion of the fan and forming a part of the air passageway, said scroll being of an archimedic design; said scroll having two ends, one said end closely adjacent the fan and the other said end removed from the fan, said ends positioned with respect to a line drawn through the center of the fan and normal to the projected air flow of the fan, such that both ends are on the same side of the line in the direction of the projected air flow and the removed end is a substantially greater distance from said line than the adjacent end; each said scroll end immediately adjacent and connected to an interior wall of the passageway such that the distance between the scroll ends substantially equals the width of the passageway, means for heating air disposed adjacent said scroll in said passageway, motor means mounted in said housing for rotating said fan about its axis and cover means for covering the air passageway and for directing heated air out of the apparatus, means for preventing the heated air from recirculating through the heating elements comprising a lip formed on said housing between the fan and the means for directing heated air out of the apparatus, adjacent said air direction means and a front cover plate mounted to the housing over the lip.