FR3034786A1 - ROTARY DRUM DRYER HAVING ADJUSTABLE RUNNING BLADES - Google Patents

Abstract

The dryer (2) for drying aggregates comprises a rotary drum (4) for receiving aggregates, vanes (12, 14) disposed on the inner surface (16) of the drum (4) to lift aggregates. and causing them to fall back due to the rotation of the drum (4), and a burner to generate a flow of hot gas in the drum (4). The dryer (2) comprises adjustable lift vanes (14), each adjustable lift blade (14) is at least partly movable relative to the drum (4), and a synchronization mechanism connecting the lift vanes (14). adjustable so that changing the setting of an adjustable tilt blade (14) results in a corresponding change in the setting of the other adjustable tilt blades (14).

Description

The present invention relates to the field of rotary drum dryers for the drying of aggregates, for example for the production of bituminous mixes, in particular paving mixes for road surfacing. To produce road paving mixes, it is possible to dry and heat aggregates and then mix the dry and hot aggregates with binder, including an asphalt binder, to produce asphalt paving. As an option, it is possible to mix dry and hot aggregates with aggregates from recycled mixes. For the drying of aggregates, it is possible to use a dryer comprising a drum rotatably mounted about its axis inclined relative to the horizontal plane, lifting blades disposed on the inner surface of the drum to lift the aggregates due to the rotation. drum and drop them by forming a curtain of aggregates inside the drum, and a burner generating hot gases circulating in the drum. In operation, the drum is fed with wet and cold aggregates. Because of the rotation of the drum, the aggregates are raised by the lifting blades and fall forming a curtain of aggregates through which the hot gases produced by the burner. The aggregates advance inside the drum due to successive tilts and the inclination of the axis of the drum relative to the horizontal plane, being gradually dried and heated. The fumes generated by the hot gas passing through the curtain of aggregates and out of the drum are recovered and filtered. To ensure a good performance, the fumes must be neither too cold, because it entails a risk of condensation, nor too hot, because it involves an overconsumption of energy. Depending on the shape of the lifting blades, the lifting blades reveal a quantity of aggregate more or less important, the curtain of aggregates formed in the rotating drum is more or less dense, and the heat exchange between hot gases and aggregates is more or less intense, which influences the temperature of the fumes leaving the dryer. It is possible to provide adjustable lifting vanes, to adjust the dryer depending on the production to be performed, particularly depending on the humidity of the aggregates used, the temperature of the desired asphalt at the output of the production facility. coated, or a recycle rate of asphalt.

US 3,641,683 discloses a rotary drum dryer comprising adjustable lift vanes pivotally mounted on the drum, each blade being able to be immobilized in several different setting positions by means of a respective adjustment bar. No. 5,083,382 discloses a rotary drum dryer comprising lift blades pivotally mounted on the drum, each blade being detachable in a plurality of setting positions by means of a sliding pin in a groove having a plurality of notches, each notch defining a respective setting position. US 5,515,620 discloses a rotary drum dryer comprising adjustable lift vanes, each blade being attachable to the inner surface of the drum selectively in three distinct setting positions.

US 2003/0227815 A1 discloses a rotary drum dryer comprising adjustable lift vanes, each vane being attachable to the inner surface of the drum selectively in two distinct setting positions. However, these rotary drum dryers are tedious to use, which increases the dryer idle time between two consecutive productions between which it is necessary to adjust the adjustable blades. One of the aims of the invention is to provide a rotary drum dryer for drying aggregates, the use of which is simplified. To this end, the invention provides a dryer for drying aggregates, the dryer comprising a rotary drum for receiving the aggregates, blades 20 disposed on the inner surface of the drum to lift the aggregates and make them fall because of the rotation of the drum, and a burner for generating a flow of hot gas in the drum, the dryer comprising adjustable lift blades, each adjustable lift blade is at least partly movable relative to the drum, and a synchronizing mechanism connecting the Adjustable lift vanes so that changing the setting of an adjustable lift blade results in a corresponding change in the setting of the other adjustable lift vanes. In particular embodiments, the dryer comprises one or more of the following optional features: each adjustable tilt blade is at least partially pivotable relative to the drum; the synchronization mechanism comprises synchronization rods, each synchronization rod being articulated on two adjustable lifting blades; it comprises a control element disposed inside the drum between an adjustable lifting blade and the inner surface of the drum, and making it possible to immobilize this selectively adjustable lifting blade in a plurality of adjustment positions; 3034786 3 - it comprises a control mechanism configured for controlling the adjustment of the lift blades adjustable from outside the drum, in particular from an axial end of the drum; the control mechanism comprises at least one control link arranged to exert traction on an adjustable lifting blade so as to modify the adjustment of this adjustable lifting blade; - The control mechanism comprises two control links arranged to act in opposite directions on the adjustable lifting vanes; the control mechanism comprises an elastic return device provided for exerting a return force on the adjustable lifting vanes towards a determined adjustment position; - The return device exerts a tensile force on one of the links to generate a return force on the adjustable lift blades, the other link for exerting a force on the lift blades adjustable in the opposite direction; The dryer is a single drier or a dye-mixer, co-current or counter-current. The invention and its advantages will be better understood on reading the description which follows, given solely by way of nonlimiting example and with reference to the appended drawings, in which: FIG. 1 is a schematic side view a rotary drum dryer for drying aggregates; - Figures 2 and 3 are sectional views of the drum, showing a row of blades comprising adjustable lifting blades, respectively in two different setting positions; Figures 4 and 5 are views similar to those of Figures 2 and 3, illustrating a variation; - Figures 6 and 7 are views similar to those of Figures 2 and 3, illustrating another variant; Figures 8 and 9 are partial side views of the dryer of Figures 6 and 7, illustrating a control mechanism for controlling adjustable lift vanes from outside the drum; - Figure 10 is a detail view of a dryer illustrating a variant; and Figures 11 and 12 illustrate rotary drum dryers according to variants. The rotary drum dryer 2 illustrated in FIG. 1 comprises a drum 4 having a longitudinal axis A-A '. The drum 4 is tubular and extends along its longitudinal axis A-A '. The drum 4 is rotatably mounted about its longitudinal axis A-A '.

The longitudinal axis A-A 'of the drum 4 is oblique with respect to a horizontal plane. The longitudinal axis A-A 'forms a non-zero angle with the horizontal plane and a non-zero angle with the vertical direction. The angle of inclination of the longitudinal axis AA 'of the drum 4 relative to the horizontal plane is for example between 2 ° and 100, in particular between 3 ° 5 and 5 ° The drum 4 comprises an inlet 6 for the aggregates wet and cold, formed by an axial end of the drum 4, and an outlet 8 for dry and hot aggregates, formed by the opposite axial end of the drum 4. The inlet 6 is located at a height greater than that of the outlet 8, due to the inclination of the longitudinal axis AA 'of the drum 4 relative to the horizontal plane. In operation, the granules circulate in the drum 4 progressively advancing from the inlet 6 to the outlet 8. The dryer 2 comprises rows 10 of lifting blades 12, 14 disposed on the inner surface 16 of the drum 4. The blades 12, 14 are arranged to raise the aggregates present in the drum 4 due to the rotation of the drum 4, and fall back to form a curtain of aggregates. The lifting blades 12, 14 are arranged in a drying section 18 of the drum 4. The lifting blades 12, 14 of each row 10 are distributed circumferentially on the inner surface 16 of the drum 4. The lifting blades 12, 20 14 of each row 10 are located at the same axial position along the longitudinal axis AA 'of the drum 4. The dryer 2 comprises a burner 20 arranged to generate hot gases flowing axially inside the drum 4. The burner 20 is arranged to form a flame inside the drum 4. The flame is generated in a flame section 22 of the drum 4. The flame section 22 is distinct from the drying section 18. The dryer 2 of FIG. a counter-current dryer. The burner 20 is arranged to generate hot gases flowing axially in the drum 4 in the opposite direction of the aggregates. The burner 20 is arranged to generate hot gases flowing axially in the drum 4 from the end of the burner 20 to the inlet 6. The drying section 16 is situated upstream of the flame section 22, considering the direction of circulation of aggregates from the entrance 6 to the exit. In a variant, the dryer 2 is a co-current dryer. The burner 20 is arranged to generate hot gases flowing axially in the drum 4 in the same direction as the aggregates. The burner 20 is then arranged to generate hot gases 35 flowing axially in the drum 4 from the end of the burner 20 to the outlet 8. The drying section 16 is then located downstream of the flame section 22 in the direction circulation of aggregates from the inlet 6 to the outlet. The dryer 2 comprises a feed device 24 for supplying the inlet 6 with wet and cold aggregates. The feed device 24 is for example a belt conveyor 5 arranged to discharge the aggregates into the inlet 6. The dryer 2 comprises a flue gas collector 26 for recovering the fumes generated by the hot gases and leaving the drum 4. In the dryer 2 against the current of Figure 1, the flue gas collector 26 is disposed at the inlet 6. In a cocurrent dryer variant, the flue gas collector is disposed at the outlet 8.

The dryer 2 here comprises several rows of lifting blades 12, 14. At least one of the rows 10 of lifting blades 12, 14 comprises adjustable lifting vanes. Figures 2 and 3 illustrate a row 10 of lifting blades 12, 14 comprising fixed 12 lifting blades and adjustable lifting blades 14.

Each fixed tilt blade 12 is non-adjustable. Each lifting blade 12 fixed is stationary relative to the drum 4. Each adjustable lifting blade 14 is at least partially movable relative to the drum 4. Each adjustable tilt blade 14 is mounted movable in part or in total relative to the drum 4, preferably by pivoting about a rotation axis, preferably an axis of rotation B - B 'parallel to the longitudinal axis A - A' of the drum 4. Each adjustable lifting blade 14 is positionable in a plurality setting positions. The adjustment positions of each adjustable tilt blade 14 make it possible to adjust the amount of material raised by the tilting blade 14 due to the rotation of the drum 4, and thus to adjust the density of the aggregate curtain formed by the lifting blades 12, 14 due to the rotation of the drum 4. Each adjustable tilt blade 14 is adjustable between a first extreme position of adjustment (Figure 2) and a second extreme position of adjustment (Figure 3). Preferably, each lift blade 14 is adjustable in a plurality of intermediate positions between the first position and the second position. This makes it possible to form curtains of aggregates of increasing density, passing from the first position to the second position. Adjustment of the adjustable tilt blade 14 is done in a discrete manner, with a predetermined number of intermediate or continuous positions, with an infinity of possible intermediate positions.

3034786 6 The adjustment of each adjustable tilt blade 14 makes it possible to vary the volume of a trough-shaped container delimited by the tilting blade 14, and in which aggregates are carried off because of the rotation of the drum 4 In the dryer of FIGS. 2 and 3, each adjustable lifting blade 14 is in part movable relative to the drum 4. Each adjustable lifting blade 14 has a movable part 30 mounted to move relative to the drum 4. The movable part 30 each adjustable lifting blade 14 is pivotally mounted about an axis of rotation B - B 'with respect to the drum 4. The axis of rotation B - B' of the movable part 30 is parallel to the longitudinal axis A - A 'of the drum 4.

A modification of the adjustment of the adjustable tilt blade 14 corresponds to a rotation of the movable portion 30 of the tilt blade 14 adjustable with respect to the drum 4. Each adjustable tilt blade 14 comprises a fixed part 32 fixed on the inner surface 16 of the drum 4. The movable portion 30 extends the fixed portion 32 inwardly of the drum 4.

The fixed part 32 is fixedly mounted relative to the drum 4, and the movable part 30 is movably mounted on the fixed part 32 so as to be movable relative to the drum 4. The movable part 30 is here pivotally mounted around the axis of rotation B - B 'on the fixed part 32. The movable part 30 and the fixed part 32 have the shape of elongated plates 20 in the direction of the longitudinal axis A - A'. The adjustable lifting blade 14 is thus formed of two plates hinged to one another, a fixed plate (fixed part 32) being fixedly mounted on the inner surface 16 of the drum 4, and the other plate (moving part 30) being pivotally mounted on the fixed plate. Adjustment of the position of the moving part 30 modifies the profile of the raising blade 14 adjustable in view along the longitudinal axis A-A 'of the drum 4 (FIGS. 2 and 3). In the illustrated example, the fixed portion 32 is substantially flat and extends radially from the inner surface 16 inwards, and the movable portion 30 is curved by falling back in the direction of rotation of the drum 4, illustrated by the Arrow R in Figures 2 and 3.

The dryer 2 comprises a timing mechanism 34 interconnecting the adjustable lift blades 14 of the row 10, so that the adjustable lift blades 14 are synchronized. The adjustable lifting blades 14 are set jointly via the synchronization mechanism 34.

The modification of the setting of one of the adjustable tilt vanes 14 connected by the synchronization mechanism 34 causes a corresponding modification of the adjustment of the other adjustable tilt vanes 14 connected by the synchronization mechanism 34 via the synchronization mechanism 34. The synchronization mechanism 34 comprises synchronization connecting rods 36 interconnecting the adjustable lifting blades 14 of the row 10.

Each synchronizing rod 36 is articulated on two adjustable lifting blades 14. A modification of the adjustment of one of the two adjustable lifting blades 14 connected by a synchronizing rod 36, is transmitted by the synchronizing rod 36 to the other adjustable lifting blade 14.

For each pair of adjustable lifting blades 14 connected by a synchronizing rod 36, a modification of the adjustable one of the lifting blades 14 causes a corresponding modification of the adjustment of the other lift blade 14 adjustable via synchronizing rod 36 connecting these two lift blades 14 adjustable.

The adjustable lifting blades 14 of the row 10 are connected in series along the circumference of the drum 4. The modification of the adjustment of an adjustable lifting blade 14 is transmitted step by step by the synchronizing rods 36 to the other blades of lift 14 adjustable. The timing mechanism 34 of the dryer 2 of FIGS. 2 and 3 more specifically synchronizes the movable portions 30 of the adjustable lift vanes 14. The synchronizing rods 36 are hinged to the moving parts 30 and connect the moving parts in series along the circumference of the drum 4. The displacement of a movable part 30 of one of the synchronized adjustable lifting blades 14 causes a corresponding movement of the parts movable 30 of the other lifting blades 14 25 adjustable. The dryer 2 comprises a control mechanism 38 for locking one of the lift blades 14 adjustable in a specific setting position relative to the drum 4. The control mechanism 38 of Figures 2 and 3 comprises a rigid control element 40 connecting a adjustable lifting blade 14 and the inner surface 16 of the drum 4. The control element 40 is here a control rod. The control member 40 is configured to immobilize the lift blade 14 which is selectively adjustable in one of a plurality of discrete adjustment positions.

In the dryer 2 of FIGS. 2 and 3, the control element 40 is connected to the inner surface 16 of the drum 4 by means of a fastening element 42 mounted immovably on the inner surface 16 and having a series of orifices 44 for fixing the control element 40. Each orifice 44 allows the maintenance of the lift blade 14 adjustable in a respective angular position with respect to the drum 4. The control element 40 is articulated on the lift blade 14 adjustable.

Alternatively or optionally, the control element 40 comprises a series of orifices for connecting the control element 40 to the adjustable lifting blade 14, the various orifices making it possible to immobilize the adjustable lifting blade 14 in different setting positions relative to the drum 4. The control mechanism 38 more specifically allows to immobilize the movable portion 30 of an adjustable lifting blade 14. The operating element 40 is connected to this moving part 30. In operation, the drum 4 is rotated about its longitudinal axis AA 'and fed with wet and cold aggregates through its inlet 6. The aggregates are raised by the blades 12, 14 and fall down forming a curtain of aggregates traversed by the hot gases generated by the burner 20. Because of the successive raisings, the aggregates progressively advance from the inlet 6 to the outlet 8, being progressively dried and heated. The density of the aggregate curtain formed by the lifting blades 12, 14 is a function of the adjustment of the adjustable lifting blades 14. To change the setting of the 20 adjustable tilt blades 14, the dryer 2 is stopped and an operator enters the drum 4 to manually change the position of the control member 40, which changes the setting of the tilt blade 14 adjustable to the control element 40, and correspondingly the adjustment of the other lift blades 14 adjustable, due to the synchronization mechanism 34.

Thus, the work of the operator is simplified since he performs a single adjustment operation for all the adjustable lifting blades 14 of the row 10. The stop time of the dryer 2 between two different productions is therefore reduced, which increases the activity rate of the dryer 2. In the dryer 2 of Figures 2 and 3, every second lifting blade of the row 10 is adjustable, and every second lifting blade of the row 10 is fixed. The fixed lifting blades 12 and the adjustable lifting blades 14 are alternated on the circumference of the drum 4. The dryer 2 of FIGS. 4 and 5 differs from that of FIGS. 2 and 3 in that all the lifting blades of a row 10 are lift blades 14 adjustable.

Each adjustable vane 14 is partly movable, and the movable portion 30 of each tilt vane 14 of the row 10 is connected to the movable portion 30 of the following tilting vane 14 by a synchronizing rod 36. In the dryer 2 of Figures 2 and 3, it is necessary for an operator to enter the drum 4 to adjust the control mechanism 40 manually to change the blade setting. This adjustment therefore requires waiting for the cooling of the drum 4 before the operator can enter inside the drum 4 to change the setting of the lift blades 14 adjustable. The dryer 2 of FIGS. 6 to 9 differs from those of FIGS. 2 and 3 in that it comprises a control mechanism 38 configured for controlling the lift blades 14 adjustable from outside the drum 4, more particularly since axial end of the drum 4. As shown in FIGS. 6 and 7, the control mechanism 38 comprises a first control link 46 arranged to exert traction on an adjustable lifting blade 14 so as to jointly modify the adjustment of the blades lift 14 adjustable synchronized in one direction, and a second control link 48 arranged to exert traction on a lifting blade 14 adjustable so as to jointly change the setting of the adjustable lift blades 14 synchronized in the other direction of rotation.

The first control link 46 and the second control link 48 are flexible links, such as a cable, a chain or a strap. As can be seen in FIGS. 8 and 9, the first control link 46 is guided from the lifting blades 14 towards an axial end of the drum 4, here the inlet 6, so as to be able to control the adjustable lifting blades 14 from this axial end of the drum 4, more specifically the position of the moving parts 30 of the lift blades 14 adjustable. The first control link 46 is guided towards this axial end of the drum so as to coincide substantially with the longitudinal axis A-A '. The first control link 46 is connected at its opposite end to the adjustable lifting blades 14, to an actuator 50 for exerting traction on the first control link 46. The actuator 50 is disposed outside the drum 4, here at the input 6. The actuator 50 comprises an actuator link 52 connected to the end of the first control link 46 coming out of the drum 4 by a connector 54 allowing a relative rotation of the actuator link 52 relative to the first control link 46 around 3034786 10 the longitudinal axis A - A '. This avoids the twisting of the first control link 46 during the rotation of the drum 4 about its longitudinal axis A - A '. The control mechanism 38 is manual or motorized drive to exert traction on the first control link 46. The actuator 50 is for example 5 a winch, motorized or manual drive. The manual training is done for example using a crank. The control mechanism 38 comprises an elastic return device 56 exerting a permanent traction force on the second control link 48. The elastic return device 56 comprises a support 58 mounted immobile inside the drum 4 and a spring of reminder 60 disposed between the support 58 and the second control link 46 to exert the traction force on the second control link 46. The return device 56 and the second control link 48 recall the lifting blades 14 adjustable towards the setting position corresponding to the curtain of least dense aggregate, and the actuator 50 and the first control link 46 allow 15 to pivot the lift vanes 14 adjustable to the setting position corresponding to the curtain of granulate the denser to the against the return force exerted by the return device 56. In a variant, the return device 56 and the second control link 48 recall the blades of 14 can be adjusted to the setting position corresponding to the curtain of the densest granulate, and the actuator 54 and the first control link 46 make it possible to urge the raising blades 14 adjustable towards the adjustment position corresponding to the curtain of granulate the less dense against the return force exerted by the return device 56. The control mechanism 38 comprises first guide members 62 for guiding the first control link 46 and second guide members 64 for guiding the second control link 48. The first and second guide members 62, 64 are carried by a support bar 66 disposed across the drum 4. The first guide members and the second guide members 30 here comprise pulleys. As an option or alternatively, the first guide members and / or the second guide members comprise at least one elbow in which a control link passes, a tube around which a control link passes and / or a groove in which passes a command link. In the dryer 2 of FIGS. 6-9, adjustment of the adjustable lift blades 14 is effected from outside the drum 4, by pulling the first control link 46 to move the adjustable lift vanes 14 to a position of 3034786 11 setting corresponding to a denser aggregate curtain against the elastic return device 56, or by releasing the first control link 46 to move the adjustable lift blades 14 to a setting position corresponding to a curtain less granulate dense, under the effect of the return of the elastic return device 56.

The driers 2 of FIGS. 2 to 9 comprise lifting blades 14 partly movable relative to the drum 4, each adjustable lifting blade 14 comprising a movable part 30, the actuation of the control mechanism 38 making it possible to modify the position of the the movable portion 30 of each lift blade 14 adjustable. In variants, the lifting blades 14, each of which is adjustable in part movable relative to the drum 4, are replaced by adjustable lifting blades 14 each movable as a whole relative to the drum 4. FIG. 10 is a detailed view of FIG. a dryer 2 having adjustable lifting blades 14 mounted movable in their entirety with respect to the drum 4. Each adjustable lifting blade 14 is pivotally mounted relative to the drum 4 about an axis of rotation B - B ', which is here parallel to the longitudinal axis A - A 'of the drum 4. A change in the setting of the tilt blade 14 corresponds to a rotation of the tilt blade 14 adjustable in its entirety with respect to the drum 4. The modification of the orientation of each lift blade 14 adjustable with respect to the drum 4 changes the volume of the trough-shaped vessel defined by the adjustable lift blade 14. The various synchronization mechanisms 34 and the various control mechanisms 38 of the dryers 2 of FIGS. 1 to 9 can be used with adjustable lifting blades 14 each movable as a whole with respect to the drum 4. The synchronization rods 36 connect to each other the lift blades 14 adjustable. The control mechanism 38 (not visible in FIG. 10) makes it possible to immobilize one of the adjustable lifting blades 14. The dryer 2 of FIG. 1 is a simple countercurrent dryer, configured to only dry wet and cold aggregate, which comes out dry and hot from the drum 4. However, the invention is not limited to simple counter-current dryer, but also applies to a single drier or a drier-mixer, co-current or countercurrent. Figure 11 illustrates a countercurrent drier-mixer 2. The dryer-mixer 2 of Figure 11 comprises, in its drying section 18, at least one row 10 comprising synchronized adjustable lift blades.

The dryer-mixer 2 of Figure 11 differs from the dryer of Figure 1 in that the drum comprises, downstream of the flame section 22, a kneading section 70. The dryer-kneader 2 comprising a boom 72 for the introduction of a binder into the kneading section 70. The drum 4 is provided on its inner surface 16, in the kneading section 70, of mixing blade 74 for mixing the aggregates with the binder. Optionally, as illustrated in FIG. 11, the drier-kneader 2 comprises a recycling ring 76 located axially between the drying section 18 and the kneading section 70, and making it possible to introduce into the drum 4 aggregates from recycled mixes, and already coated with binder. Figure 12 illustrates a co-current drier-mixer 2. The dryer-mixer 2 of Figure 12 differs from that of Figure 10 in that the burner 20 is arranged to generate a flow of hot gas flowing in the drum 4 in the same direction as the aggregates, the inlet 6 to the outlet 8. The flame section 22 is upstream of the mixing section 15. In a co-current dryer or co-current dryer-mixer equipped with a one-row synchronized adjustable lift control mechanism, the control mechanism is preferably arranged to be controlled from the outlet 8 of the drum 4, since the burner 20 generally occupies the inlet 6, as illustrated in FIG. 12. The various variants of adjustable lift blades and synchronization mechanisms and control mechanisms described in relation with FIGS. at 10, are adaptable to different types of rotary drum dryer for drying aggregates, namely single dryers and dryers-blenders, co-current or countercurrent. In general, the dryer 2 may comprise both adjustable lifting blades 14 movable relative to the drum 4, adjustable lifting blades 14 having a movable portion relative to the drum 4, and / or fixed lifting blades 14 in the same row 10 or in different rows 10.

In general, the dryer 2 may comprise a single row of lifting blades or several rows of lifting blades. A drier 2 with a plurality of rows 10 of tilt blade exclusively comprises rows having adjustable lift vanes or comprises at least one row having adjustable lift vanes and at least one row having exclusively fixed lift vanes.

3034786 13 Each row having adjustable lift vanes exclusively includes adjustable lift vanes, or includes adjustable lift vanes and fixed lift vanes. 5

Claims (10)

1. A dryer (2) for drying aggregates, the dryer (2) comprising a rotary drum (4) for receiving aggregates, vanes (12, 14) disposed on the inner surface (16) of the drum (4). ) for raising the aggregates and lowering them due to the rotation of the drum (4), and a burner (20) for generating a flow of hot gas in the drum (4), the dryer (2) comprising lifting blades (14) adjustable, each adjustable tilt blade (14) is at least partly movable relative to the drum (4), and a synchronization mechanism connecting the tilt vanes (14) adjustable so that the modification of the setting of an adjustable lifting blade (14) causes a corresponding change in the setting of the other adjustable lifting blades (14). 2. Dryer according to claim 1, wherein each adjustable lifting blade (14) is at least partly pivotable relative to the drum (4). 3. Dryer according to claim 1 or 2, wherein the synchronization mechanism comprises synchronization rods, each synchronization rod being articulated on two lifting blades (14) adjustable. 4. Dryer according to any one of the preceding claims, comprising a control element disposed inside the drum (4) between an adjustable lifting blade (14) and the inner surface (16) of the drum (4), and to immobilize the lift blade (14) selectively adjustable in a plurality of adjustment positions. 5. Dryer according to any one of claims 1, 2 or 3, comprising a control mechanism configured for controlling the adjustment of the lifting blades (14) adjustable from outside the drum (4), in particular from an axial end drum (4). 6. Dryer according to claim 5, wherein the control mechanism comprises at least one control link arranged to exert traction on a lifting blade (14) adjustable so as to modify the adjustment of this blade lift (14). adjustable. 7. Dryer according to claim 6, wherein the control mechanism comprises two control links arranged to act in opposite directions on the lifting blades (14) adjustable. 8. Dryer according to any one of claims 5 to 7, wherein the control mechanism comprises an elastic return device provided for exerting a return force on the lifting blades (14) adjustable to a specific setting position. 3034786 15 9. Dryer according to claims 7 and 8, wherein the return device exerts a tensile force on one of the links to generate a return force on the adjustable lifting blades, the other link to exert an effort on the lift blades are adjustable in the opposite direction. 5 10. Dryer according to any one of the preceding claims, the dryer being a single drier or a drier-mixer, co-current or against the current.