Rotary dryer having notched flights
View Patent ↗A dryer adapted for use in an asphalt plant. The dryer includes a drum having an inner wall and a flight having a proximal end connecting the flight to the inner wall of the drum and a distal end that is spaced apart from the proximal end. A first profile extends from the proximal end to the distal end of the flight and defines a flight shape. A notch is formed in the distal end of the flight, which notch includes a notch shape that is defined by a second profile. The second profile has a length L, a center point, and a portion that substantially approximates a conic section.
1. A dryer adapted for use in an asphalt plant, the dryer comprising:
a drum having an inner wall;
a flight having a proximal end connecting the flight to the inner wall of the drum and a distal end that is spaced apart from the proximal end;
a first profile extending from the proximal end to the distal end that defines a flight shape of the flight;
a notch formed in the distal end of the flight having a notch shape that approximates a conic section and that is defined by a second profile, the second profile having a length L, a notch center, and formed by a pair of notch profile portions with ends joined together at the notch center and opposite ends joined to the distal end of the flight, each notch profile portion comprising a spline of at least two sections connected together at ends and that are each defined by a different polynomial function and have a different curvature.
2. The dryer of claim 1 wherein the first profile comprises a partial conic section formed by a spline of at least two sections connected together at end and including at least two sections that have a different curvature.
3. The dryer of claim 1 wherein at least a portion of the first profile is curved.
4. A dryer apparatus comprising:
a flight configured for use in a dryer in an asphalt plant and having a proximal end configured to mount to an inner surface of a drum of the dryer and a distal end, wherein a shape of the flight is continuous and curved; and
a notch disposed in the distal end of the flight, the notch having a notch center and being defined by a continuous curve that approximates a conic section and that is formed by a pair of notch profile portions with ends joined together at the notch center and opposite ends joined to the distal end of the flight, each notch profile portion comprising a spline of at least two sections connected together at ends and that each have a different curvature.
5. The dryer of claim 1 wherein the at least two sections of each notch profile portion comprise a straight section and a curved section.
6. The dryer of claim 1 wherein each notch profile portion comprises a spline of at least three sections that are each defined by a different polynomial function to provide a different curvature.
7. The dryer of claim 1 wherein the spline of each notch profile portion includes two or more conic sections that are each selected from the group consisting of a hyperbola and a parabola.
8. The dryer of claim 7 wherein each notch profile portion further includes at least one straight section.
9. The dryer apparatus of claim 4 wherein the spline includes at least one curved section and one straight section.
10. The dryer apparatus of claim 4 wherein the spline is continuously curved without bends.
11. A dryer flight configured for placement within a drum of a dryer and configured to scoop, carrying, and shower asphalt material within the drum as the drum is rotated, the dryer flight comprising:
a proximal end configured to connect the flight to an inner wall of the drum;
a distal end that is spaced apart from the proximal end;
a flight shape beginning at the proximal end and ending at the distal end of the flight that is defined by a spline having three or more sections joined together at ends, wherein the three or more sections include at least two of the following types of sections that are each defined by a polynomial function: a straight section, a parabolic section, or a hyperbolic section, wherein the end of the section is located where the type of section changes from one type of section to another type of section or where the polynomial function and curvature of the section changes to a different polynomial function and different curvature;
a notch formed in the distal end of the flight having a notch shape defined by a pair of notch portions joined together at a notch center of the notch and extending to the distal end of the flight, a shape of each notch portion defined by a spline having three or more sections joined together at ends, wherein the three or more sections include at least two of the following types of sections that are each defined by a polynomial function: a straight section, a parabolic section, or a hyperbolic section, wherein the end of the section is located where the type of section changes from one type of section to another type of section or where the polynomial function and curvature of the section changes to a different polynomial function and curvature.