Agricultural products drying heater

Claim 2

Agricultural products-drying heater apparatus for drying agricultural products in bins to which the unit is coupled, comprising an axially elongated substantially cylindrical tubular shell having an ambient air inlet end and a heated air outlet end, a motor driven propeller-type fan mounted in said shell intermediate said ends for producing a current of air in said shell flowing from said inlet end to said outlet end, an annular fuel burner unit in said shell between said fan and said inlet end defining a ring structure adjacent the outer wall of the shell surrounding an open center region and forming a circular flame zone concentric with the shell axis, and an airfoil member in said shell upstream of the burner unit between the latter and said inlet end including a cylindrical center tube portion extending axially through the open center region of said ring structure to a location adjacent the motor of said fan to form an inner core stream of cooling air for cooling said motor, said airfoil member having a truncated conical skirt portion joined to the upstream end of said center tube portion and diverging outwardly and downstream therefrom to a location adjacent the burner ring structure to produce turbulence conditions providing substantially even temperatures across the whole area of said outlet end, said burner ring structure comprising an inner cylindrical ring of sheet material, an outer cylindrical ring of sheet material coaxial with and spaced outwardly from said inner ring, and a fuel pipe arranged in a closed circle path in a plane perpendicular to the axis of the shell joined to the upstream edges of said inner and outer rings to define a downstream opening annular chamber therebetween in which combustion occurs, said pipe having fuel outlet orifices opening into said combustion chamber, said outer ring including a radially outwardly projecting flange extending continuously around the same at its downstream edge.

Claim 3

Apparatus as defined in claim 3 wherein the downstream edge of said conical skirt portion of said airfoil member is located closely adjacent and radially inwardly of said inner ring, and wherein said center tube portion extends through and downstream beyond the open center space surrounded by said inner ring.

Claim 4

Apparatus as defined in claim 3, wherein said conical skirt portion diverges downstream to a diameter close to the internal diameter of said ring structure.

Claim 5

Apparatus as defined in claim 3, wherein said tubular shell defines a discontinuous tubular wall having two axially spaced sections of uniform diameter extending from said inlet end to said outlet interrupted by a circumferential slot forming an inlet for secondary air.

Claim 6

Agricultural products drying heater apparatus for drying agricultural products in bins to which the unit is coupled, comprising an axially elongated substantially cylindrical tubular shell having an ambient air inlet end and a heated air outlet end, a motor-driven propeller-type fan mounted in said shell intermediate said ends for producing a current of air in said shell flowing from said inlet end to said outlet end, an annular fuel burner unit in said shell between said fan and said inlet end defining a ring structure adjacent the outer wall of the shell surrounding an open center region and forming a circular flame zone concentric with the shell axis, and an airfoil member in said shell upstream of the burner unit between the latter and said inlet end including a cylindrical center tube portion extending axially through the open center region of said ring structure to a location adjacent the motor of said fan to form an inner core stream of cooling air for cooling said motor, said air foil member having a truncated conical skirt portion joined to the upstream end of said center tube portion and diverging outwardly and downstream therefrom to a location adjacent the burner ring structure to produce turbulence conditions providing substantially even temperatures across the whole area of said outlet end, said tubular shell defining a discontinuous tubular wall having two axially spaced sections of uniform diameter extending from said inlet end to said outlet interrupted by a circumferential slot forming an inlet for secondary air.

Claim 7

Agricultural products drying heater apparatus for drying agricultural products in bins to which the unit is coupled, comprising an axially elongated substantially cylindrical tubular shell having an ambient air inlet end and a heated air outlet end, a motor driven propeller-type fan mounted in said shell intermediate said ends for producing a current of air in said shell flowing from said inlet end to said outlet end, an annular fuel burner unit in said shell between said fan and said inlet end defining a ring structure adjacent the outer wall of the shell surrounding an open center region and forming a circular flame zone concentric with the shell axis, and an airfoil member in said shell upstream of the burner unit between the latter and said inlet end including a cylindrical center tube portion extending axially through the open center region of said ring structure to a location adjacent the motor of said fan to form an inner core stream of cooling air for cooling said motor, said airfoil member having a truncated conical skirt portion joined to the upstream end of said center tube portion and diverging outwardly and downstream therefrom to a location adjacent the burner ring structure to produce turbulence conditions providing substantially even temperatures across the whole area of said outlet end, said conical skirt portion diverging downstream to a diameter close to the internal diameter of said ring structure, said tubular shell defining a discontinuous tubular wall having two axially spaced sections of uniform diameter extending from said inlet end to said outlet end interrupted by a circumferential slot forming an inlet for secondary air.