DE3414365A1 - DEVICE FOR TREATING BITUMINOESE MIXED MATERIAL, IN PARTICULAR ROAD CONSTRUCTION ASPHALT - Google Patents

Abstract

A reduction in the overall dimensions of the entire installation and in energy losses is achieved with at the same time improved handling characteristics of the installation and a comparative simplification of its construction by the fact that the rock mixture which is dried in a dry rotary drum (1) and constitutes the aggregate is introduced immediately after passing through the dry rotary drum (1) into an annular chamber (12) between the dry rotary drum (1) and another drum (13) surrounding the latter and is mixed with the bitumen or bitumen-containing material; next, the aggregate produced passes through the annular chamber (12) in the opposite direction to the movement of the rock mixture in the dry rotary drum (1) up to a delivery device (29).

Description

Equipment for processing bituminous mix, especially

special road construction asphalt.

The invention relates to a device for processing bituminous material Mixture, especially road construction asphalt, with a drying rotary drum, which heatable by means of a burner arrangement and in which by means of a conveyor device a rock mixture can be introduced as aggregates from one end, which is also designed so that the rock mixture with the drum rotation in the direction migrates to the other end of the rotary drying drum and which over a Exhaust duct can be vented by means of a suction fan1 and with a mixing device for adding bitumen to the dried rock mix.

In known devices of this type, this is done in the drying rotary drum Dried and heated rock mix is discharged from the rotary drying drum and conveyed up by means of a hot elevator to after falling through a sieve device to get sorted according to grain size into a dosing and mixing device in which Batch quantities of aggregate of the required grain size from storage compartments taken and with dosed sprayed bitumen in a mixer. be mixed.

A device constructed according to this known principle has one takes up considerable space, is technically complex and causes energy losses.

Other known devices for processing bituminous mix see an introduction of the rock mixture into the drying rotary drum already in the desired composition in terms of grain size proportions before, so that after Removal of the rock mix from the drying rotary drum and conveying up via the bitumen can be added using a hot elevator in a mixing drum, which is injected into the rotating mixing drum. The mix can come out removed from the end of the mixing drum remote from the rotating drying drum and be delivered to a storage silo.

This known system also has considerable dimensions in the direction of the drum axis Requires space and makes complex measures to isolate the system parts against Heat losses required.

Also known devices for processing bituminous Mixtures are designed in this way; that the rotary drying drum is also the mixing device forms, the bitumen directly into the drying rotary drum along a certain axial length of the same is injected in a region - in which the into the Dry rotary drum with the desired composition of the aggregate introduced already dried to a sufficient extent by heating the drying rotary drum is. Facilities of this type have the advantage of requiring little space and a comparatively simple structure, but considerable difficulties arise the setting of a stable operation in such a way that overheating of the Bitumen due to excessive heating of the rotary drying drum by the in they directed burner flame on the one hand is avoided and on the other hand a adequate drying of the rock mix before the union is achieved with the sprayed bitumen. so that the bitumen on the surfaces the aggregate adheres satisfactorily. Next has the facilities of last-mentioned type the problem arise that the exhaust gases from the drying rotary drum especially during the commissioning of the system with bitumen mist or from it resulting combustion products can be offset, thereby arranged in the exhaust duct Dust collectors clog and become ineffective. A charge of uncleaned Exhaust gases from the rotary drying drum of the last-mentioned known device in the environment is unsuitable, at least in inhabited areas, and in many countries. strictly prohibited in Europe in particular.

The object of the invention is to be achieved, a device with the features of the preamble of claim 1 in such a way that a small space requirement of the entire system and a reduction in energy losses and a simplification of the structure can be achieved and an adjustment at the same time the drying result or the heating of the input in the rotary drying drum Rock mix on the one hand and the addition and dosage of the binding agent on the other is possible essentially independently of one another.

This task is achieved by the characterizing features of claim 1 solved.

Advantageous refinements and developments are the subject of appended claims 2 to 15, the content of which is hereby expressly an integral part the description is made; without repeating the wording at this point.

It should be noted that it is from the German patent specification 1 217 992 is known per se, a focus on the drying of the rock mix subsequent process step in the processing of bituminous Mixture, namely the classification into aggregate proportions of a certain grain size, to be laid in a sieve drum coaxially surrounding the rotating drying drum and thereby an advantageous compact design of the entire device without one of the rotary drying drum downstream hot elevator and an adjoining screening device obtain. However, the sieve drum of the known device does not offer the possibility of carry out other process steps besides the sieving process in it.

Before a detailed description of the exemplary embodiments is given A preferred embodiment is briefly discussed at this point.

According to this preferred embodiment, the annular space between Rotary drying drum and the additional drum surrounding it via a separate one Exhaust duct vented, which opens into the exhaust duct for the drying rotary drum and contains a throttle member, so the from the burner assembly in the rotary drying drum Introduced thermal energy through appropriate setting of the throttle element between the two working spaces of the facility, namely the interior of the rotary drying drum and the annular space between the drying rotary drum and the other surrounding it Drum can be divided as required.

The setting of the throttle member can be made so that already in the start-up phase of the facility, in which not all System parts are in thermal equilibrium, an optimal drying result the rock mix and at the same time sufficient heating of the mix containing annular space between the rotary drying drum and the further drum because the suction fan takes part of the hot exhaust air and the combustion gases from the drying drum immediately above the connected Exhaust duct sucks off another part of this hot exhaust air and the combustion gases but via wall breaks in the rotary drying drum and the aforementioned annular space accordingly the setting of the throttle member via the other containing the throttle member Exhaust duct pulls off. Overheating or burning of the bitumen from too strong Heating the mix can safely be avoided. At the same time it results the main advantage of a good utilization of the thermal energy, which due to the high temperatures in the interior of the rotary drying drum radiated from its jacket and in the case of the device specified here in the one surrounding the rotary drying drum Annular space is also made available for heating.

A few exemplary embodiments are described below with reference to the drawing described. 1 shows a schematic view of an axial section through a device working with countercurrent drying for the processing of bituminous Mixture of the type specified here FIG. 2 with a variant compared to FIG Co-current drying working embodiment of a device for processing of bituminous mix, also shown in an axial section, Fig. 3 a Axial section through one of the device according to Figure 1 similar device with a Mixing feed device for adding old asphalt, FIG. 4 shows an axial section by a device similar to the device according to FIG. 2 with an admixing feed device for the addition of old asphalt and Fig. 5 is an axial section through a device similar to the device according to Figure 1, each with separate storage and drive devices for the rotary drying drum and the others surrounding it Drum and with another burner arrangement for additional heating of the the rin space surrounding the rotary drying drum.

First of all, it should be noted that in the drawing figures 1 to 5 shows the bituminous processing equipment shown in axial section Mixture are shown shortened in the axial direction to provide an overall view of the essentials To be able to reproduce parts of the system in a representation.

In practice, however, have the rotary drying drum and the surrounding area Another drum compared to the axial dimension shown is about twice the length. However, other proportions of the dimensions can also be determined by a person skilled in the art at any time to be provided if necessary.

The device shown in Figure 1 includes a rotary drying drum 1, which is closed at its front end by an end wall 2, which over a drum rotation allowing sealing gap 3 to the rotary drying drum adjoins. A conveyor belt 5 extends into the through an opening 4 of the end wall 2 Inside the drying rotary drum.

The conveyor belt 5 is used to input a prepared rock mix with the desired grain proportions in the interior of the rotary drying drum.

At its rear end, on the right in FIG. 1, is the rotating drying drum 1 completed by an end wall 6, which has a drum rotation permitting sealing gap 7 adjoins the rotary drying drum 1. Will the drying rotary drum 1 offset in rotation, so it moves rock mix to be dried, which is entered via the conveyor belt 5 into the interior of the rotary drying drum has been gradually in the direction of arrow P in the rotary drying drum of left to right, with the rock mixture due to the drum rotation with the help of internals not shown in the drawings, for example in the form of blading the inner wall of the drum. is transported up on this and then falls down in the drum, with hot combustion gases flowing from right to left in the rotating drying drum cause intensive drying of the rock mix.

The hot combustion gases are generated by a burner 8, which via an opening in the end wall 6 into the interior of the rotary drying drum 1 extends and a burner flame directed axially into the rotary drying drum 1 9 generated. The burner 8 can be fed with the usual fuels.

The end wall 2 is provided with an opening, one of which Exhaust duct 10 leads away, which is connected to a suction fan. This in the Drawings suction fan, not shown, sucks combustion products from the rotary drying drum, Exhaust gas and water vapor from.

Near the burner end of the rotary drying drum 1 is the Wall provided with Durchbxmchen 11, which such axial and circumferential dimension show that the dried rock mixture when it is on its way through the Rotary drying drum reaches the area of the openings from left to right, falls through this completely into an annular space 12, which between the Outer wall of the drying rotary drum 1 and a further drum surrounding it 13 is formed.

The further drum 13 is against the rotating drying drum 1 above in Figure 1 only schematically indicated spokes 14 supported. However, it should be noted: that the support of the rotary drying drum with respect to the further drum also means a blading spanning the annular space 12 can take place.

The spokes 14 also serve to support races 15 against the rotary drying drum 1 bridging the annular space 12, so that the rotary drying drum 1 by means of the races 15 and flanged rollers 16 cooperating with them is stored, bearing and drive means not shown in detail in the drawing as well as drive motors cause the drum to rotate.

The further drum 13 has in the embodiment according to FIG 1 such an axial length that it is not only in the section between the two Races 15 shown extends, but also to the left of the left race 15 and located to the right of the right race 15 has drum sections.

It is important that the drying rotary drum 1 the cantilevered through the spokes 14 and the Laufrinqe 15 supported structural part of the drum assembly forms, which in turn serves to support the further drum 13 from a number of arcuate wall elements is assembled in such a way that the annular space 12 for carrying out maintenance or repair work by acceptance individual or all wall elements of the further drum 13 made accessible can be.

The construction described allows, deviating from the in The embodiment shown in FIG. 1 shows the further drum 13 only in the axial area to be provided between the races 14 or to be provided with such an axial length, that the further drum 13 does not extend beyond the race 15 on the left side. According to yet another embodiment, the further drum 13 can also only in the area of a freely cantilevered part of the rotary drying drum 1 outside of Area of the races 15 of the rotary drying drum are provided.

There is also the possibility of 1 the rotary drying drum 1 on in FIG Equip 1 right-hand end with a smaller axial length, so that the drying rotary drum 1 ends at a certain axial distance from the end of the further drum 13 and that dried rock mix from the rotary drying drum 1 from the one on the right Drum opening falls directly onto the inner wall of the further drum 13, wherein openings 11 can be dispensed with in this modified embodiment.

One not shown in FIG. 1 for the sake of clarity Inner blading of the further drum 13 has the effect that the breakthroughs 11 in the area 17 in the annular space 12 falling material gradually from the area 17 opposite to the direction of migration within the dry rotary drum with reference to the representation of Figure 1 again moves to the left, the material due to the drum rotation is carried up on the inner wall of the further drum 13 and constantly within the annular space 12 again to the lower region of the further drum 13 partially falls and partially slides down.

A bitumen metering device 18 includes a gear motor 19 and a bitumen pump 20, from which an injection line 21 through an opening the end wall 6 in the annular space between the rotary drying drum 1 and the other Drum 13 extends in and ends near area 17 in an injection nozzle. the The bitumen is added to the dried rock mix by spraying of bitumen preferably where the dried barley in a mixture through the openings 1 falls through onto the inner wall of the further drum 13.

It should also be noted that the end wall 6 has a drum rotation permitting sealing gap 22 adjoins the further drum 13.

On the side of the further drum facing away from the openings 11 13 this extends into a collector housing 23 which is attached to the drum 13 a sealing gap 24 allowing drum rotation is adjacent. Another that Annular gap 25 allowing drum rotation is between the collector housing 23 and the Rotary drying drum 1 is provided, as is readily apparent from FIG. from a separate exhaust gas duct leads to the collector housing 23 in its upper region 26 away, which contains a throttle element 28 which can be adjusted by means of an actuating drive 27.

In the lower area is the collector housing 23 with a discharge opening 29 for removing the bituminous mix from the annular space 12. The discharge opening 29 is connected to an extraction channel 30 which leads to an extraction silo 31, and is designed as a double lock to avoid sucking in false air.

Will the migration of the rock mix in the drying rotary drum 1 by inclining its axis to form a slope from left to right generated, the further drum 13 must be bladed on its inner wall are provided, which the migration of the mix produced in area 17 in forces the further drum 13 from right to left. In a corresponding way must if the migration of the material to be mixed in the further drum is due to a gradient is generated from right to left, the rotary drying drum on its inner wall be provided with a blading, which the gradual migration of the rock mix forces in the drying rotary drum from left to right. Is the axis of rotation of the Rotary drying drum 1 and the further drum 13 surrounding it horizontally, see above have to to generate the desired direction of migration of the material both drums are equipped with corresponding blading on their inner wall will. The creation of migration of the material in the drums only by inclination the respective rotary drum axis is possible if the rotary drying drum and the further drum are each separately stored and driven. Such a one Construction is discussed in more detail below.

Control lines not shown in the drawing can be used by the actuator 27, the drive for the conveyor belt 5, the drive for the one connected to the exhaust gas duct 10 Suction fan, the control means for the burner 8 and for the gear motor 19 to a central control unit to run the entire facility automatically to be able to control it shows that the adjustability of the throttle element 28 a distribution of the thermal energy generated by the burner 8 on the interior of the rotary drying drum 1 and the annular space 12 allows, so that the drying result with respect to the rock mixture on the one hand and the result of the preparation of the bituminous mix on the other can be optimized.

The embodiment of Figure 2 differs from the device according to Figure 1 in that in the Ausführungsfotm according to Figure 2 in contrast to the construction according to Figure 1 of the burner 8 via an opening in the end wall 2 extends into the interior of the rotary drying drum 1, while the exhaust duct 10 leads away from an opening in the end wall 6 on the right-hand side of the device, such that the flow of hot exhaust air and combustion gases in the rotating drying drum 1 is oriented from left to right and a direct current drying of the rock mix is carried out.

Similar to the embodiment of Figure 1, the separate, the AbJgasEka ** alv26 containing adjustable throttle element to the collector housing 23 connected, as in Figure 2 at 26a, 27a and 28a for the expert in sufficient Dimensions is made clear. By such a construction it is achieved that the for the annulus 12 to be branched off hot combustion gases through the openings 11 get into the annular space 12 and there with reference to the representation of FIG 2 flow through the annulus from right to left and a considerable duration of action is achieved within the annular space 12.

The embodiment according to FIG. 3 corresponds in principle Structure in all details of the construction according to Figure 1. In addition, however the device shown in Figure 3 is provided with an admixing feed device 33, which includes a screw conveyor 34 from an input hopper 35 via a Breakthrough in the end wall 6 extends into the interior of the rotary drying drum 1. The front end of the screw conveyor 34 and the shell surrounding it is located near the breakthroughs 11. By means of the admixture feed device 33, pieces of old asphalt together with the rock mixture dried in the drying rotary drum into the Entered area 17 and after additional addition of bitumen by means of the bitumen metering device 18 passed through the annular space 12 and heated in this annular space. The adjustability of the throttle element 28 in the separate exhaust gas duct 26 is essentially ensured a setting independently of the drying process within the rotary drying drum 1 the heat supply to the mixed material mixed with old asphalt within the annulus 12th

According to a modified embodiment, the admixing feed device 33 also extends into the rotary drying drum 1 and is designed to be conveyed into it be.

The embodiment shown in Figure 4 corresponds in his basic structure of the embodiment according to Figure 2. The embodiment also contains according to Figure 4 in a corresponding manner as described in connection with Figure 3, an admixture feed device 33 with a screw conveyor 34 and the input hopper 35 for feeding of old asphalt. The other exhaust duct 26, which the throttle member is in turn connected to the collector housing 23.

Finally, the embodiment of FIG. 5 contains some noteworthy ones Modifications to the previously described embodiments.

In the device according to Figure 5, the annular space 12 opens at his on the right, the end adjacent to the burner 8 in an input collector housing 36 a, which via the drum rotation permitting annular gaps 37 and 38 to the other Drum 13 or the rotating drying drum 1 is adjacent. Another burner arrangement 39 extends through an opening in the input collector housing 36 and is capable of one To direct the burner flame 40 into the annular space 12. The one available in the annulus 12 Thermal energy is so in the embodiment of Figure 5 by regulating the Throttle member 28 and by the heat supply through the burner 39 essentially Regulated independently of the conditions in the interior of the rotary drying drum 1.

It can also be seen from Figure 5 that the rotary drying drum 1 and the further drum 13 surrounding them each have separate bearing and drive means each with separate races, flange rollers and drive motors.

The separate storage for the drying rotary drum 1 and the further drum 13 enables the two drums to be eccentric relative to one another to store to on a drum side larger dimensions of the annular space 12 for the Processing of the mixed material available. Next, the drums can be opposite each other and / or at different speeds in rotation will. Finally, due to the basic structure shown in FIG the possibility of each different Inclination of the drum rotation axes to be provided to the migration of the material within the drums accordingly influence.

Due to the different types of exhaust gases coming from the interior the rotary drying drum on the one hand and the annular space 12 on the other hand escape, is an advantageous development not shown in the drawing better dedusting and filtering then achieved when in the exhaust duct 10 and in the separate Exhaust gas duct 26 each have separate, different dedusting devices or Filters are provided.

Finally, in Figures 1 to 4 at 41 by dash-dotted lines Lines indicate a housing surrounding the essential parts of the device, which is provided with insulation to further reduce heat losses can be.

Claims (15)

Claims 1. Device for processing bituminous mix, in particular road construction asphalt, with a drying rotary drum (1), which by means of a burner arrangement (8) can be heated, in which by means of a conveying device (5) a rock mixture can be introduced as aggregate from one end, which is also designed so that the amount of rock during drum rotation in the direction migrates to the other end of the rotary drying drum and which over a Exhaust gas duct (10) can be vented by means of a suction fan, as well as with a mixing device for adding bitumen to the dried rock mix, characterized in that that the drying rotary drum is surrounded by a further drum (13), which is rotatable about an axis substantially parallel to the rotary drying drum, that the interior of the rotary drying drum (1) close to its from the conveyor device (5) remote end with the annular space (12) between the drying rotary drum (1) and the further drum (13) is connected, that the mixing device is a bitumen metering device (18) contains, by means of which the bitumen in said annulus (12) near the Area of connection between the interior of the rotary drying drum (1) and the Annular space (12) can be sprayed and that the further drum (13) is designed so that in it the mixed material is opposite to the direction of migration of the rock mix migrates to a discharge device (29, 30, 31). 2. Device according to claim 1, characterized in that the interior the rotary drying drum (1) and the annular space (12) via openings (11) in the drum wall the drying rotary drum are in communication. 3. Device according to claim 1 or 2, characterized in that the exhaust gas duct (10) at the end of the rotary drying drum remote from the conveying device (5) (1) is connected to this and that the burner assembly (8) on that of the conveyor Near the end of the rotary drying drum (1) a burner flame directed into it (9) generated. 4. Device according to claim 1 or 2, characterized in that the exhaust gas duct (10) at the end of the rotary drying drum that is close to the conveyor device (5) (1) is connected to this and that the burner assembly (8) on that of the conveyor distant end of the rotating drying drum (1) a burner flame directed into it generated. 5. Device according to one of claims 1 to 3, characterized in that that the annular space (12) between the rotary drying drum (1) and the further drum (13) near the end facing the conveyor device by means of a separate exhaust gas duct (26) which contains an adjustable throttle element (28) and in particular into the exhaust duct (10) connected to the interior of the rotary drying drum (1) joins. 6. Device according to claim 5, characterized in that in the separate exhaust gas duct (26) and in which to the interior of the rotary drying drum (1) connected exhaust duct (10) each with separate dedusting devices are arranged. 7. Device according to one of claims 1 to 6, characterized in that that the rotating drying drum (1) and the further drum (13) are parallel to one another Have axes, in particular are arranged coaxially to one another. 8. Device according to claim 7, characterized in that the rotary drying drum (1) and / or the further drum (13) are cylindrical or polygonal in cross section are. 9. Device according to one of claims 1 to 8, characterized in that that the rotary drying drum (1) and the further drum (13) with internal blading are provided to generate the migration of the rock mix or the mixed material. 10. Device according to one of claims 1 to 9, characterized in that that the further drum (13) via spokes (14) provided in the annular space (12) the rotary drying drum (1) is connected and that bearing and drive means (15, 16) intended to support the drums and to generate the drum rotation are. 11. Device according to one of claims 1 to 9, characterized in that that the rotary drying drum (1) has a greater axial length than the further drum (13) and that each separate storage and drive means for the drying rotary drum and the further drum are provided. 12. Device according to one of claims 1 to 10, characterized in that that by means of the bitumen metering device (18) the bitumen in that area (17) of the annular space (12) between the rotating drying drum (1) and the further drum (13) can be sprayed into which the rock mixture from the rotary drying drum (1) falls into the annular space (11). 13. Device according to one of claims 1 to 12, characterized in that that an admixture feed device (33, 34, 35) for adding Altaspahlt the side facing away from the conveying device (5) for inputting the rock mixture the rotary drying drum (1) protrudes into this or the annular space (12). 14. Device according to one of claims 1 to 13, characterized in that that by means of a further burner arrangement (39) at least one approximately axially in the Annular space (12) between the rotating drying drum (1) and the further drum (13) reaching burner flame (40) can be generated. 15. Device according to one of claims 1 to 14, characterized in that that the further drum (13) can be at least partially dismantled axially and circumferentially divided, arched wall elements is composed.