WO2013144518A1

WO2013144518A1 - Device and method for producing hot-mix products

Info

Publication number: WO2013144518A1
Application number: PCT/FR2013/050684
Authority: WO
Inventors: Antoine Carrasco
Original assignee: Argumat
Priority date: 2012-03-29
Filing date: 2013-03-28
Publication date: 2013-10-03
Also published as: FR2988741B1; FR2988741A1

Abstract

The invention concerns a device for producing hot-mix products, for example with bitumen, comprising: - a furnace comprising an enclosure (2) that is rotated, said enclosure (2) being provided with a main inlet intended to receive granular products, and an outlet (30), said granular products flowing from the main inlet towards the outlet, - a heating means defining a combustion section (5) in the enclosure (2) and generating a drying flow, said enclosure (2) continuing into a drying section (6), then into a mixing section (7), characterised in that the enclosure (2) is provided with a system (12) for discharging the hot granulates, said system (12) being integrated between the drying section and the mixing section and being positionable between an active position and an inactive position.

Description

DEVICE AND METHOD FOR MANUFACTURING HOT COATED PRODUCTS

TECHNICAL FIELD The present invention relates to the general technical field of devices and processes for manufacturing hot-mix products, for example with bitumen, for obtaining bituminous coated products, from a mass of aggregates or solid granular products. , whether new and cold aggregates and / or used bituminous products to be recycled or a mixture of both, in order to achieve a finished coated product used for example in the field of construction and public works.

The present invention relates more particularly to a device for manufacturing hot-coated products, for example with bitumen, comprising:

an oven comprising a substantially cylindrical enclosure intended to be rotated about its longitudinal axis by a drive means, said enclosure being provided towards its two opposite ends, on the one hand with a main inlet intended to receive products; uncoated or recycled virgin granules or a mixture of both, pebbles or aggregates, and secondly an outlet for bituminous coated products made in the enclosure, said granular products circulating from the main entrance to the outlet according to a direction F to become coated products at the exit, after passage and treatment in the enclosure,

a heating means defining a combustion section in the chamber and generating a drying flow capable of ensuring the drying of the granular products, said chamber continuing from said combustion section by a drying section and then by a section mixing. The invention also relates to a method of manufacturing hot mixes in a coating drum dryer comprising a substantially cylindrical chamber composed of a series of successive sections comprising a combustion section, a drying section and a mixing section. PRIOR ART

The devices for manufacturing hot-coated products, in particular bituminous coated products, are known and generally consist of rotary kilns generally qualified coating drying drums (TSE). The techniques used may be continuous or discontinuous techniques and operate, depending on the relative displacement of the heating flow and aggregates, according to the so-called parallel current (or even-current) or counter-current techniques. current.

Known manufacturing devices and methods use a drying oven generally in the form of a cylindrical body of revolution defining an enclosure having at least one inlet at one of its ends and an outlet at the other end. the drying oven being rotated by any suitable means while the mass of aggregates or pebbles to be treated is introduced at one end so as to progress towards the outlet end to be treated.

The rotation of the enclosure thus makes it possible to circulate the aggregates that enter cold and wet through the inlet, towards the other outlet end while stirring and raising them in the enclosure with the help of any appropriate means, and for example using lifting blades mounted on the inner peripheries of the walls of the enclosure.

The known furnaces also use a heating flux produced by a burner associated with the enclosure, which burner furnishes a flame in a combustion zone of the enclosure, the flame emitting a hot air flow circulating, depending on the type oven, against the current or in the direction of circulation of the cold and wet aggregates inside the enclosure. In general, the known rotary kilns implement a coating drum dryer which is composed of a series of successive sections comprising, in consideration of the direction of progression of the aggregates inside the furnace, a combustion section, then a section drying and finally a kneading section. The traditional operation of these conventional rotary kilns means that the aggregates, whether new or used aggregates or a mixture of both, necessarily pass through the final mixing section within which is injected in an automated manner and controlled a fraction of liquid bitumen that is precisely mixed in the mixing zone with the aggregates to obtain the final product at the outlet of said mixing zone.

This technique is generally satisfactory but is not perfectly adapted to all types of coated products that can be manufactured and in particular so-called "special" coated products for which particular conditions of mixtures may be desired or required, these particular conditions mixtures should not involve, at least at this stage of manufacture, a passage in the mixing zone leading to an immediate mixing with liquid bitumen. It may indeed be necessary to resort to various treatments prior to coating with bitumen, where it may be necessary to perform special operations on hot aggregates, for example coloring aggregates after drying .

SUMMARY OF THE INVENTION

The objects assigned to the invention therefore aim to remedy the various disadvantages listed above and to propose a new device and a new process for producing hot-mix products, for example with bitumen, which are particularly versatile and capable of to adapt to various situations of industrial production.

Another object of the invention is to propose a new device and a new method of manufacturing hot-mix products which are particularly simple and effective to implement. Another object of the invention is to propose a new device and a new process for manufacturing hot-mix products which are particularly robust and proven in its operation.

The objects assigned to the invention are achieved by means of a device for manufacturing hot-coated products, for example with bitumen, comprising:

an oven comprising a substantially cylindrical enclosure intended to be rotated about its longitudinal axis by a drive means, said enclosure being provided towards its two opposite ends, on the one hand with a main inlet intended to receive products; uncoated or recycled virgin granules or a mixture of both, pebbles or aggregates, and on the other hand an outlet for the bituminous coated products made in the enclosure, said granular products circulating from the main entrance to the outlet according to a direction F to become coated products at the exit, after passage and treatment in the enclosure,

a heating means defining a combustion section in the chamber and generating a drying flow capable of ensuring the drying of the granular products, said chamber continuing from said combustion section by a drying section and then by a section characterized in that the enclosure is provided with a system for discharging hot aggregates, said system being integrated between the drying section and the mixing section and being positionable between an inactive position in which the hot aggregates are discharged from the drying section to the mixing section and an active position in which the hot aggregates are discharged from the enclosure without passing through the mixing section. The objectives assigned to the invention are also attained by means of a process for manufacturing hot mixes in a coating drum comprising a substantially cylindrical enclosure composed of a series of successive sections comprising a combustion section, a drying section and a mixing section characterized in that it is possible selectively to ensure the removal of hot aggregates at the outlet of the drying section out of the drying drum enrobeur either their passage to the kneading section from the drying section.

SUMMARY DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will become apparent and will be described in more detail on reading the description given below, with reference to the appended drawings, given solely by way of illustrative and nonlimiting example, in which:

- Figure 1 illustrates, in a longitudinal cross-sectional view, a general view of a hot-coated product manufacturing device according to the invention. - Figure 2 shows, in a perspective view and in partial cross section taken along the line ll-ll of Figure 1, the details of embodiment of a selective two-position evacuation system according to the invention and integrated in a manufacturing device according to the invention.

- Figures 3 and 4 illustrate, in cross-sectional views, a selective evacuation system according to the invention in position, respectively, inactive and active discharge of hot aggregates.

- Figure 5 illustrates, in a partial sectional view, a detail of embodiment of the selective exhaust system according to the invention.

- Figure 6 illustrates in a partial cross-sectional view, a detail of embodiment of a control means equipping the device for manufacturing hot-coated products according to the invention.

- Figure 7 illustrates in a perspective view, a detail of embodiment of a ring forming part of the device for manufacturing hot-coated products according to the invention. BEST MODE OF REALIZING THE INVENTION

Figure 1 illustrates in a longitudinal cross-sectional view, a general view of a device for manufacturing hot-coated products, for example with bitumen, to manufacture bituminous coated products. The device illustrated in FIG. 1 is, for purely illustrative purposes, a so-called parallel-current device insofar as the heating flux F flows in the same direction as the direction of feed and progression of the granular products illustrated by the arrow F inside the device.

It should nevertheless be noted that the invention can also be applied to devices for manufacturing hot-mix products, in particular bituminous, said "against the current" devices in which the heating flow F flows in the opposite direction to that coated products to be dried and processed into bituminous coated products.

In the same way, the device for manufacturing hot-coated products according to the invention will be either a continuous manufacturing device or a device for the discontinuous production of hot coated products.

The device for manufacturing hot-coated products illustrated in FIG. 1 comprises a furnace 1 or coater-drying drum comprising a substantially cylindrical enclosure 2 intended to be rotated about its longitudinal axis XX 'by a drive means (not shown). in the figures), said enclosure 2 being provided at its two opposite ends, firstly with a main inlet 3 intended to receive virgin granules and uncoated or recycled products or a mixture of the two, the kind of pebbles or aggregates, and on the other hand, an outlet 30 for the bituminous coated products manufactured in the enclosure 2, said granular products circulating from the main inlet 3 towards the outlet 30 in a direction F to turn into coated products at the outlet 30, after passage and treatment in the enclosure 2. As is well known to those skilled in the art, the drive means (not shown in the figures) will comprise, in a manner known in itself, a source of energy, of the motor type, driving [enclosure 2 itself, by a series of gears or conventional drives, consisting for example of rollers 4 engaging drive means secured to the outer wall 2A of the enclosure 2.

Thus, the device for manufacturing hot-coated products according to the invention is a coating drum dryer composed, from the inlet 3, of a series of successive sections each having a specific function, the successive sections comprising a section of 5, a drying section 6 and a mixing section 7 opening towards or into the outlet 30. Said successive sections are advantageously contained in the chamber 2, which is substantially cylindrical.

For the purposes of the invention, the expression "uncoated virgin granular product" will be understood to mean any type of the product of the genus type aggregates, pebbles, granules, sand or the like, having sufficient mechanical strength to be used in the manufacture of the product. coated product of all kinds likely to be used as construction materials in the field of public works, such as roads or walls, without such applications are therefore limiting. In the same way, within the meaning of the invention will be understood by the expression "recycled granular products" any type of products of the kind aggregates, pebbles, aggregates, sands or other having already been used as road construction materials or others having already been in this respect provided with a coating based on bitumen, such products are therefore intended to be recycled and stripped of their coating to be re-coated.

All these virgin or recycled granular products therefore have a very heterogeneous particle size, a physical and chemical composition which is also very heterogeneous and which also has various sizes, shapes, moisture content, consistency and so on. extremely varied. In general, the rotary kiln is designed so that the virgin or recycled granular products, or a mixture of both, flow from the main feed inlet 3 to the outlet 30 during the rotation of the enclosure 2, for transforming, after successive passage: first in a combustion zone 5 in which opens the main entrance 3 in the form of a channel 8 (Figures 3 and 4), then in the drying zone 6, provided for example of lifting blades 6A, and finally in the mixing zone 7 in which it is also possible, for example, to continuously introduce, for example, a liquid coating product, for example bitumen, by way of a tubing 9 to produce a final bituminous coated product to the outlet 30.

As illustrated in FIG. 1, the device for manufacturing hot-coated products according to the invention also comprises a heating means 10 associated with the combustion section 5, said heating means 10 being thus disposed in the vicinity of the input 3 in the specific exemplary embodiment illustrated. For example, the heating means 10 is constituted by a burner 11 producing a drying flame which extends substantially axially in the central zone of the drying section 6 to generate a drying flow circulating within the enclosure 2 in the direction F and thus ensuring the drying of the granular products within the drying section 6.

The heating means 10 thus defines the combustion section 5 in the chamber 2 and generates a drying flow F able to ensure the drying of the granular products, said chamber continuing from said combustion section 5 and contiguous to the direction F, by a drying section 6 and then by a mixing section 7.

According to an important characteristic of the invention, the enclosure 2 is provided with a system for discharging hot aggregates 12, which system is selective and for example at two positions, said system 2 being integrated between the drying section 6 and the mixing section 7, and being positionable between an inactive position in which the hot aggregates are removed from the drying section 6 to the mixing section 7 and an active position in which the hot aggregates are removed from the chamber 2 without go through the mixing section 7. Thus, and according to the position likely to occupy the discharge system 12, the device according to the invention allows in its inactive position to normally transfer the hot aggregates to the kneading section 7, for example using buckets 13 mounted inside the chamber 2 to allow the hot aggregates to be kneaded with bitumen in said mixing section, whereas when the discharge system 1 is in the active position, it allows the evacuation of the aggregates through the discharge device 12, even through a discharge outlet 14. In this way, the device according to the invention allows a dual possibility of operation of the furnace which can thus be adapted to several conditions. of operation and for example:

or to the production of bituminous mix by passing through the kneading section 7 with injection of the bitumen via the pipe 9,

- Or to the production of hot aggregates for mixing with bitumen outside the mixing section 7, and for example in another manufacturing unit, avoiding the mixing section 7 through the exhaust system 12 when is in its active position.

Moreover, such a system makes it possible to optimize the operation of the device according to the invention by authorizing at the beginning and end of manufacture to evacuate the beginnings and end of manufacture whose compositions are often heterogeneous, which makes it possible to ensure the granuiometric homogeneity of the coated product. The evacuation system 12 can also be used to verify the correct operating parameter of the furnace before launching a complete production.

Particularly advantageously, the selective exhaust system 12 is formed by a ring 15 mounted on the enclosure 2 and at its periphery, said ring 15 being mounted movably between the active position and the inactive and positionable position on or in the one or other of these two positions opposite orifices 16 formed through the chamber 2 in an annular zone situated opposite the ring 15.

In the same way, the ring 15 is provided with openings 17 which coincide with the orifices 16 of the enclosure 2 when the ring 15 is in the active position of evacuation. As illustrated, the orifices 6 and openings 17 will be of all shapes and sizes adapted to allow, in conventional operation of the device, a fluid discharge of the hot aggregates out of the enclosure 2.

Preferably, the openings 17 will for example be of rectangular shape as illustrated in FIG.

According to a particularly preferred version of the invention, the ring 15 is concentrically mounted with the enclosure 2 about the axis X-X 'and movable by rotation about said enclosure 2 and about said axis XX'.

As a variant, it is of course conceivable to mount a movable ring according to other freedom of movement, and for example by translation between the periphery of the enclosure 2, without departing from the scope of the invention.

Particularly advantageously, and as illustrated, the ring 15 is formed by a cylindrical cap of U cross-section with a core 15A and two folded lateral wings 15B, the openings 17 being formed through the core 15A of the U As illustrated, and preferably, the openings 17 are distributed angularly over the entire peripheral surface of the ring 15 and at regular intervals, the orifices 16 of the chamber 2 being formed through the chamber 2 at intervals. also regular and angularly distributed appropriately so that in the inactive (or closing) position of the ring 15 (FIG. 3), said orifices 16 and openings 17 are completely offset without any overlapping whereas in the active position (or total opening) of the system 12, said orifices 16 and openings 17 are in total or maximum coincidence.

Of course, within the meaning of the invention, the relative intermediate positions of the orifices 16 and openings 17 are also conceivable outside the end positions of abutment in total coincidence (active position) or in total offset (inactive position), from the moment when a relative passage is possible so that the hot aggregates can be evacuated through the discharge outlet 14. Particularly advantageously, the ring 15 is displaceably mounted by means of a series of rollers 18 interposed between the enclosure 2 and the ring 5 so as to allow the evacuation system to be rotated. .

Finally, as illustrated, the interface zone of the chamber 2 located between the end of the drying section 6 and the beginning of the kneading section 7 and which corresponds to the installation area of the evacuation system. , is formed by an annular outer casing 19 providing a seal between the two sections 6 and 7 and defining, in its lower part, the discharge outlet 14.

As illustrated in FIG. 5, the evacuation system 12 according to the invention is provided with a control means 20 for positioning and passing said evacuation system 12 in one or the other of these so-called active or inactive positions.

According to a preferred version of the invention, the control means 20 is formed on the one hand by at least one cleat 21 integral with the evacuation system 12 and protruding from said system so that its position can be detected, and secondly by at least one position detector 22 operatively connected to a control member (not shown) adapted to act on the latch 21 to move the ring 15 to its active or inactive position.

As illustrated in the figures, the tab 21 extends radially from the web 15A of the ring 15 towards the outside of said ring 15 and positioned substantially in a central position from the web 15A between two successive openings. 17.

According to this arrangement, it is thus possible to easily locate the angular position of the catch 21 and consequently of the ring 15 and to control its position by means of the catch 21, the control system 20 being brought into contact with the catch 21 for a predefined time, depending on the speed of rotation to allow to move the position of the ring 15 and bring the exhaust system 12 in its active or inactive position. Finally, the device according to the invention is formed by a device with a parallel flow or against the current, the heating flow F being able to flow in the same direction as the direction of progression of the granular products or in the opposite direction, that is, to say against the current. The invention also relates to a method for manufacturing hot mixes in a coating drum comprising a substantially cylindrical chamber 2 composed of a series of successive sections comprising a combustion section, a drying section and a mixing section, said the method being such that it is possible to selectively ensure either the discharge of the hot aggregates at the outlet of the drying section 6 from the drum, or their passage to the kneading section 7 from the drying section 6,

According to the method of the invention, the heating flux is parallel flow or countercurrent. The operation of the device is as follows.

During operation, according to a continuous or discontinuous cycle, during which the hot aggregates advance in the enclosure 1 in the direction F and continuously or discontinuously are transported from the inlet 3 to the outlet 30 passing successively through all the sections 5, 6, 7 of the device to be extracted by the outlet 30 in the form of hot bituminous mix, it is possible to evacuate all or part of the hot aggregates of the enclosure 2 without passing through the section kneading 7.

For this, the control means 20, after locating the position of the catch 21 rotates the ring 15 so that the exhaust system 12 reaches its active position in which the orifices 16 and the openings 17 are in correspondence, total or partial, so that the flow of the hot aggregates is discharged through the discharge outlet 14 at the end of the drying section 6 and before entering the mixing section 7. At any time, it is possible to reverse the rotational movement of the ring 15 to position the evacuation system 12 in the inactive position in which the orifices 16 and the openings 17 are no longer in coincidence and are instead totally shifted in such a way that the flow of the hot aggregates passes, in particular using the buckets 13 of the drying section 6, to the mixing section 7 to be mixed with bitumen and extracted by the outlet 30.

The device for manufacturing hot-coated products according to the invention thus makes it possible, by means of particularly simple technical means, to increase the operating versatility of the devices for manufacturing hot-mix products and to have a simple means for controlling at best the start-up and end-of-manufacturing phases.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the design, manufacture and use of devices for manufacturing hot-mix products, for example with bitumen, and in the implementation of a process for manufacturing hot mixes .

Claims

Apparatus for producing hot-coated products, for example with bitumen, comprising:

an oven (1) comprising a substantially cylindrical enclosure (2) intended to be rotated about its longitudinal axis (Χ-Χ ') by a drive means, said enclosure (2) being provided towards its two opposite ends; on the one hand, a main inlet (3) intended to receive uncoated or recycled virgin granular products or a mixture of the two, such as pebbles or aggregates, and on the other hand an outlet (30) for bituminous coated products manufactured in the enclosure (2), said granular products circulating from the main inlet (3) to the outlet (30) in a direction F to become coated products at the outlet (30), after passage and treatment in the enclosure (2),

a heating means (10) defining a combustion section (5) in the enclosure (2) and generating a drying flow capable of ensuring the drying of the granular products, said enclosure (2) continuing from the said combustion section (5) by a drying section (6) and then by a mixing section (7), characterized in that the enclosure (2) is provided with a system for discharging (12) the hot aggregates, said system (12) being integrated between the drying section (5) and the kneading section (7) and being positioned between an inactive position in which the hot aggregates are removed from the drying section (6) to the kneading section (7) and an active position in which the hot aggregates are discharged from the enclosure (2) without passing through the mixing section (7).

Device according to claim 1 characterized in that the selective evacuation system (12) is formed by a ring (15) mounted on the enclosure (2), and at its periphery, said ring being movably mounted between the active position and the inactive position and positionnabie on one or the other of these two positions facing holes (16) formed through the enclosure (2). - Device according to claim 2 characterized in that the ring (15) is provided with openings (17) which coincide with the orifices (16) of the enclosure (2) when the ring (15) is in active position of evacuation. - Device according to claim 3 characterized in that the ring (15) is concentrically mounted with the enclosure (2) and movable by rotation around the enclosure (2). - Device according to one of claims 2 to 4 characterized in that the ring (5) is movably mounted by means of a series of rollers (4) of bearings interposed between the enclosure (2) and the ring (15). - Device according to one of claims 3 to 5 characterized in that the ring (15) is formed by a cylindrical cap of U cross section, the openings being formed through the web (15A) of the U. - Device according to one of the preceding claims, characterized in that the evacuation system (12) is provided with a control means for positioning and passing said evacuation system (12) into one or other of its so-called active or inactive positions. - Device according to claim 7 characterized in that the control means (20) is formed on the one hand by at least one cleat (21) integral with the discharge system (12) and projecting out of said system so as to that its position can be detected and on the other hand by at least one position detector (22) operatively connected to a control member adapted to act on the catch (21) to move the ring (15) towards its active position or inactive. - Device according to claim 6 and claim 8 characterized in that the cleat (21) extends radially from the core (15A) of the ring (15). - Device according to one of the preceding claims characterized in that it is formed by a parallel flow device or against the current. - A method of manufacturing hot mixes in a coating drum dryer comprising a substantially cylindrical enclosure (2) composed of a series of successive sections comprising a combustion section (5), a drying section (6) and a section of kneading (7) characterized in that it is possible selectively to ensure the discharge of the hot aggregates at the outlet of the drying section (6) out of the coater drying drum or their passage to the kneading section (7) from of the drying section (6). - Method according to claim 1 characterized in that it is implemented using a device according to one of claims 1 to 10.