US2815940A - Aggregate dryer - Google Patents

Description

AGGREGATE DRYER W. M. MADSEN Filed Feb. 23, 1954 rlllll Dec. 10, 1957 M km INVENTORQ Waller Madsen Unite St AGGREGATE DRYER Walter M. Madsen, Arcadia, Calif.

Application February 23, 1954, Serial No. 411,706

12 Claims. (Cl. 259-3) This invention relates generally to drying equipment and relates more particularly to apparatus for drying various types of aggregates used in the paving industry and the like.

While the present apparatus has particular utility in the heating and drying of aggregates, such as rock, sand, etc. used in the asphalt paving industry and is shown and described in connection with drum type dryers used in said industry, it is to be understood that its utility is not confined thereto.

In the asphalt paving industry, it is necessary to dry as well as heat the rocks and sand aggregates. These aggregates are fed or delivered to the dryer from a suitable source such as a feed bunker or tunnel by various means such as, for example, a conveyor belt or elevator.

Various problems are encountered in drum type dryers used for drying various aggregates and it is an object of the present invention to provide a dryer that is highly efficient and effective.

Another object of the invention is to provide a dryer of this character having a maximum opening within the shell so as to provide maximum productive capacity.

Still another object of the invention is to provide apparatus of this character adapted to effectively handle a greater amount of material than heretofore.

A further object of the invention is to provide apparatus of this character wherein the material is carried further up and over as the dryer shell is rotated.

A further object of the invention is to provide apparatus of this character wherein there is a delay in dropping of the material within the dryer shell.

A still further object of the invention is to reduce the number of channel lifters required.

Another object of the invention is to provide apparatus of this character which will more uniformly create aggregate curtain walls throughout the entire dryer int'erior.

Still another object of the invention is to provide apparatus of this character that is relatively simple in construction.

A further object of the invention is to provide apparatus of this character that is relatively inexpensive to manufacture.

Other objects and advantages of the invention will appear from the following part of the specification.

Referring more particularly to the drawings, which are for illustrative purposes only,

Fig. 1 is a side elevation of apparatus embodying the present invention, there being portions broken away showing certain interior structural features;

Fig. 2 is a sectional view taken on line 2--2 of Fig. l; and

Fig. 3 is a sectional view taken on line 33 of Fig. 1.

Referring more particularly to the drawings, there is shown a cylindrical shell 16 arranged substantially horiz-ontally, the inlet end 11 being higher than the outlet end 12. The shell is provided with a plurality of longitudinally spaced rows of annularly spaced elongated 2,815,940 Patented Dec. 10, 1951 openings which are substantially parallel to the axis of the shell and the openings of the rows are staggered with respect to the openings of adjacent rows. The openings 14 may be of any suitable shape but are disclosed herein as being generally rectangular with the length of said openings extending longitudinally with respect to the length of the shell.

Within the shell is provided material lifting means shown herein as comprising a plurality of longitudinally spaced rows of annularly spaced channel members or lifters, indicated generally at 15. The lifters 15 are channel-shaped or U-shaped in cross-section and have arms 16 secured to the interior wall of the shell. The opposite arms 17 extend in the direction of rotation of the device, which direction of rotation is indicated by the arrows 19. The lifters are secured to the shell by means of welding or other suitable means and at the back thereof are angle irons or members 20 which are secured to the shell and to the respective lifters by suitable means such as welding or the like. The members 20 are at the backs of the lifters 15 and 'serve to strengthen same.

The lifters 15 are adjacent to the leading edges 31 of the openings 14 and are arranged in generally parallel relationship therewith.

On the exterior of the shell 10, there are a plurality of longitudinally spaced rows of annularly spaced pockets 25, each of which is defined by a casing, indicated generally at 26 and comprising arcuately shaped walls 27 and end walls 28. There is a pocket for each opening 14 and said pockets are arranged generally parallel to the axis of the shell. Each casing 26 is substantially wider at its open end than the width of the respective opening 14 and said casing is secured to the exterior of the shell by means of welding or the like. It is to be noted that the leading edge 30 of each casing is located adjacent the leading edge 31 of the respective opening 14 and the trailing edge or side 32 of the casing is spaced rearwardly of the trailing edge 22 of said opening so that there is a portion 35 of the shell wall which serves to partially define the respective pocket.

Means for rotatably supporting the above described mechanism comprises a plurality of annular rings 37 which encircle the shell and pockets, said rings being spaced apart longitudinally with respect to the shell. The rings 37 are shown as being secured to the outer portions of the walls 27 of the casings 26 but it is to be understood that said rings may be otherwise mounted. The rings rest on rollers 38 carried by shafts 39 which are mounted in bearings 40 carried by a frame, indicated generally at 42. The frame includes longitudinally extending beams 43.

Between the rings 37 is a gear ring suitably secured to the casings 26, said ring being connected by a chain 46 to a sprocket 47 mounted on a shaft 48 having bearings 49 carried by transverse beams 50 secured tothe longitudinal beams 43; The shaft 48 extends longitudinally of the apparatus to the forward end thereof and is provided with additional bearings 52. Means for driving the shaft comprises an electric motor 53 which is connected to a gear reduction mechanism 54 having a sprocket 55 connected to a sprocket 56 on the shaft 48 by means of a chain 57.

Material to be heated and dried by the apparatus is delivered to the inlet end 11 by any suitable means shown as comprising a chute 61) which projects into the shell through an inlet opening 61 of smaller diameter than the diameter of the shell. provided with a plurality of spiral flanges or vanes 63 which provide means for feeding aggregate material quickly into the dryer and away from the inlet end so as to prevent congestions which might otherwise develop.

In operation, as the shell is rotated, the. material is de- The inlet end portion 62 is.

livered to the inlet and is moved further into the shell by the flanges or vanes 63. This material enters the lowermost pockets 25 by passing through the respective openings 14- and this pocket of material, as well as material picked up by the lifters 15, will be carried upwardly. As the material is thus carried up, a point is reached whereat said material begins to fall from the lifters and some of the pocketed material will begin to fall. The

falling material forms curt ins with the sh ll so that the heated air movin throu h the shell w ll quickly dr and heat the m terial. It is to be noted that the pocketed material will be carried further up and over during the rotati n of the drver shell than occurs wi h the material picked no by the lifters. With the combination of pockets and lifters. there are curtain walls over substantially the entire interior of the shell.

As additional material enters the shell and is moved inwardly by the vanes or flan es 63. the body f material moves toward the outlet and there is handled successively by the rows B. C. D and E of the a aratus from which it will pass outwardly and be discharged from the outlet end.

I claim:

1. Apparatus for drying various a regates used in the paving industry and the like, comprising: a cylindrical shell having an inlet at one end and an outlet at the other end. said shell having a plurality of longitudinally spaced rows of annularlv spaced enerally rectangular openings therein substantially parallel to the axis of said shell. the openings of the rows being sta ered with respect to the openin s of adiacent rows; a plurality of spiral flan es at the inlet end for feeding material into the drver; a plurality of longitudinally s aced rows of annularly spaced channel lifters, there being a lifter secured to the shell interior adiacent each opening at the leading side thereof. the lifters of each row being parallel to each other and extending parallel to the axis of the shell, the lifters of the rows being staggered with respect to the lifters of adjacent rows; a plurality of longitudinally spaced rows of annularly spaced casing members, there being a casing member for each opening in the shell secured to the exterior thereof to provide staggered rows of annularly spaced pockets parallel to the axis of the shell, each casing member comprising an arcuate wall and end walls. the casing member being open at its widest side, the leading side of each casing member being generally aligned with the leading edge of its respective shell opening, the width of said casing members being substantially greater than the width of the openings so that the portions of the shell covered by the casing members at the trailing sides of the openings partially define said pockets and provide walls adapted to carry material upwardly at the upwardly'moving side of the shell as said shell rotates and from which curtains of material gradually drop with further rotation of said shell; means for rotatably mounting said shell with the inlet end higher than thheuoutlet end; and means for effecting rotation of said s e 2. In apparatus for drying various aggregates used in the paving industry and the like: a cylindrical shell hav- 1ng an inlet at one end and an outlet at the other end, said shell having a plurality of longitudinally spaced rows of annularly spaced generally rectangular openings therein substantially parallel to the axis of said shell, the openngs of the rows being staggered with respect to the openrngs of adjacent rows; a plurality of spiral flanges at the inlet end for feeding material into the dryer; a plurality of longitudinally spaced rows of annularly spaced channel lifters, there being a lifter secured to the shell interior adjacent each opening at the leading side thereof, the lifters of each row being parallel to each other and extending parallel to the axis of the shell, the lifters of the rows being staggered with respect to the lifters of adjacent rows; a plurality of longitudinally spaced rows of annularly spaced casing members, there being a casing member for each opening in the shell secured to the exterior thereof to provide staggered rows of annularly' spaced pockets parallel to the axis of the shell, each casing member comprising an arcuate wall and end walls, the casing member being open at its widest side, the leading side of each casing member being generall aligned with the leading edge of its respective shell opening, the width of said casing members being substantially greater than the width of the openings so that the portions of the shell covered by the casing members at the trailing sides of the openings partially define said pockets and provide walls adapted to carry material upwardly at the upwardly moving side of the shell as said shell rotates and from which curtains of material gradually drop with further rotation of said shell; and means for rotatably mounting said shell with the inlet end higher than the outlet end.

3. In apparatus for drying various aggregates used in the paving industry and the like: a cylindrical shell having an inlet at one end and an outlet at the other end, said shell having a plurality of longitudinally spaced rows of annularly spaced elongated openings therein substantially parallel to the axis of said shell, the openings of the rows being staggered with respect to the openings of adjacent rows; a plurality of spiral flanges at the inlet end for feeding material into the dryer; a channel lifter secured to the shell interior adjacent each opening at the leading side thereof; a casing member for each opening in the shell secured to the exterior thereof to provide external pockets, each casing member being generally semi-circular in cross section and being open at its widest side, the leading side of each casing member being generally aligned with the leading edge of its respective shell opening, the width of said casing members being substantially greater than the width of the openings so that the portions of the shell covered by the casing members at the trailing sides of the openings partially define said pockets and provide walls adapted to carry material upwardly at the upwardly moving side of the shell as said shell rotates and from which curtains of material gradually drop with further rotation of said shell; and means for rotatably mounting said shell with the inlet end higher than the outlet end.

4. In apparatus for drying various aggregates used in the paving industry and the like: a cylindrical shell having an inlet at one end and an outlet at the other end, said shell having a plurality of longitudinally spaced rows of annularly spaced elongated openings therein substantially parallel to the axis of said shell, the openings of the rows being staggered with respect to the openings of adjacent rows; a plurality of spiral flanges at the inlet end for feeding material into the dryer; a channel lifter secured to the shell interior adjacent each opening at the leading side thereof; a casing member for each opening in the shell secured to the exterior thereof to provide external pockets, each casing member being generally semi-circular in cross section and being open at its widest side, the leading side of each casing member being generally aligned with the leading edge of its respective shell opening, the width of said casing members being substantially greater than the width of the openings so that the portions of the shell covered by the casing members at the trailing sides of the openings partially define said pockets and provide walls adapted to carry material upwardly at the upwardly moving side of the shell as said shell rotates and from which curtains of material gradually drop with further rotation of said shell; and means for rotatably mounting said shell.

5. In apparatus for drying various aggregates used in the paving industry and the like: a tubular shell having an inlet at one end and an outlet at the other end, said shell having a plurality of longitudinally spaced rows of annularly spaced generally rectangular openings therein substantially parallel to the axis of said shell; a channel lifter secured to the shell interior adjacent each opening at the leading side thereof to gradually drop material, from the upwardly moving side of the shell as it rotates to a point approximately at the uppermost rotation point for said shell; a casing member over each opening in the shell secured to the exterior thereof to provide external pockets, the width of said casing members being substantially greater than the width of the openings with portions of the shell at the trailing sides of the openings covered by the casing members to provide walls adapted to carry material upwardly at the upwardly moving side of the shell as said shell rotates and from which curtains of material gradually drop with further rotation of said shell beyond the uppermost rotation point for said shell; and means for rotatably mounting said shell.

6. In apparatus for drying various aggregates used in the paving industry and the like: a tubular shell having an inlet at one end and an outlet at the other end, said shell having a plurality of longitudinally spaced rows of annularly spaced generally rectangular openings therein substantially parallel to the axis of said shell, the openings of the rows being staggered with respect to the openings of adjacent rows; material lifters secured to the shell interior adjacent respective openings at the leading sides thereof; a casing over each opening in the shell secured to the exterior thereof to provide external pockets, the width of said casings being substantially greater than the width of the openings and said casings covering portions of the shell at the trailing sides of the openings; and means for rotatably mounting said shell.

7. In apparatus for drying various aggregates used in the paving industry and the like: a rotatably mounted tubular shell having an inlet at one end and an outlet at the other end, said shell having a plurality of longitudinally spaced rows of annularly spaced generally rectangular openings therein substantially parallel to the axis of said shell; material lifters secured to the shell interior adjacent respective openings at the leading sides thereof, the lifters being parallel to each other and extending parallel to the axis of the shell; and means defining pockets externally of the shell, there being a pocket for each opening, said openings communicating with respective pockets, each pocket having a material retaining portion disposed on the trailing side of the opening with which it communicates.

8. In apparatus of the class described: a rotatably mounted shell having an inlet at one end and an outlet at the other end; means defining a plurality of annularly spaced pockets on the exterior of the shell and parallel to the axis of said shell, said shell having openings therein providing communication between the interior of said shell and said pockets with the pockets having material retaining portions disposed on the trailing side of the openings in rotation of said shell; and material lifting means operably associated with said openings interiorly of said shell.

9. In apparatus for drying various aggregates used in the paving industry and the like: a rotatably mounted tubular shell; means defining a plurality of annularly spaced elongated pockets on the exterior of said shell, said shell having an elongated opening therein for each pocket, said openings being narrower than said pockets with a substantial portion of each pocket being disposed on the trailing side of the opening with which it communicates; and material lifting means on the interior of said shell operably associated with said openings.

10. In apparatus of the class described: a tubular shell having a plurality of openings therein; and a casing member over each opening in the shell secured to the exterior thereof to provide exterior pockets, the width of said casing members being substantially greater than the width of the openings with a portion of the shell at the trailing side of each of the openings covered by the casing members to provide walls adapted to carry material upwardly at the upwardly moving side of the shell as said shell rotates and from which curtains of material gradually drop as said shell rotates.

11. In apparatus for drying various aggregates used in the paving industry and the like, a rotatable tubular shell through which the hot drying gases pass in drying the particulate aggregate material, said shell being mounted for rotation about its longitudinal axis and having an inlet for aggregate material at one end and an outlet at the other end, a first series of material lifting means carried by and peripherally spaced around the wall of said shell with each lifting means in said series including a wall member extending inwardly of the wall of said shell and disposed to carry material upwardly and gradually drop such material to the point at which the wall member reaches approximately the uppermost point in the rotary movement of said shell, a second series of material lifting means carried by and peripherally spaced around the wall of said shell with each lifting means of said second series including a pocket carried by said shell having a material retaining portion and a mouth opening into the shell interior, the material retaining portion of said pocket being disposed to trail the mouth as the shell rotates so that a substantial part of material picked up and carried upwardly by said pocket during rotation of said shell is gradually dropped after the pocket is carried by shell rotation beyond the uppermost point in rotary movement of said shell.

12. In apparatus for drying various aggregates used in the paving industry and the like, a rotatable tubular shell through which the hot drying gases pass in drying the particulate aggregate material, said shell being mounted for rotation about its longitudinal axis and having an inlet for aggregate material at one end and an outlet at the other end with the rotation axis of said shell inclined downwardly from said inlet toward said outlet, means for rotating said shell in a predetermined direction, a plurality of material lifting means carried by and peripherally spaced around the wall of said shell to pick up material from the bottom of said shell as said shell rotates and carry the material upwardly for release in a free falling curtain extending transversely of the shell, each of said lifting means including a wall member extending inwardly of the wall of said shell and disposed to carry material upwardly and gradually drop such material to the point at which the wall member reaches approximately the uppermost point in the rotary movement of said shell and a pocket carried by said shell having a material retaining portion and a mouth opening into the shell interior, the material retaining portion of said pocket being disposed to trail the mouth as the shell rotates so that a substantial part of material picked up and carried upwardly by said pocket during rotation of said shell is gradually dropped after the pocket is carried by rotation of said shell beyond the uppermost point in rotary movement of said shell.

References Cited in the file of this patent UNITED STATES PATENTS 1,061,762 Lierfeld May 13, 1913 1,567,335 Scrive Dec. 29, 1925 2,187,601 Glaxner Jan. 16, 1940 2,660,408 Laschinger Nov. 24, 1953 FOREIGN PATENTS 334,049 Germany Mar. 9, 1921

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