WO1989003914A1

WO1989003914A1 - Heated mixer-conveyor for continuous manufacture of road asphalt or poured asphalt

Info

Publication number: WO1989003914A1
Application number: PCT/EP1988/000924
Authority: WO
Inventors: Karl Martin Stahl
Original assignee: Karl Martin Stahl
Priority date: 1987-10-22
Filing date: 1988-10-15
Publication date: 1989-05-05
Also published as: DE3735740A1

Abstract

A heated mixer-conveyor for recycling broken road asphalt comprises a heating drum (3) heated indirectly from the inside (D) and from the outside (E) and a tubular double-walled shaft (11) fitted with screw shovels (19) and paddles (20) of various shapes for conveying, crushing and mixing.

Description

description

Heating mix conveyor for the continuous production of road asphalt or mastic asphalt

The invention relates to a heating mixer conveyor for the continuous production of road asphalt or mastic asphalt by heating, crushing and mixing fresh material and / or ground road asphalt breakup in a directly or indirectly heated drum, containing a driven and rotating conveyor, a filling opening and one

Outlet opening.

Road asphalt with a bitumen content of approximately 3% by weight or mastic asphalt with a bitumen content of approximately 10% by weight is usually produced in batches in a heating mixer (boiler).

It is also known to melt broken street asphalt in a drum with direct or indirect hot gas flow using high temperatures. In this known method, it has been found to be disadvantageous that the high hot gas temperatures cause overheating of the asphalt and bitumen, which deprive the mixed material of the mixture by volatilization, thereby embrittling and coking the surfaces of the break-up. The contaminated hot gases then have to pass through extensive filters in order to clean them and to re-heat them after heating.

The invention has for its object to provide a device with the continuous road or mastic asphalt Combinations of these materials can be made from both fresh materials and ground asphalt. In particular, the invention is intended to make it possible to recycle the waste material, as it occurs in large quantities on construction sites, and to reuse it. It is the task of the device to heat up the waste material, to crush it, to mix it and, if necessary, to make it operational again by adding binders. The device according to the invention is intended to work in such a way that overheating of the material is avoided in any case and the heating, comminution, mixing can be carried out in a single device until the continuous dispensing of a directly usable product.

To achieve this object, the invention proposes a heating mixer conveyor of the generic type, in which the conveyor element is heatable as a double-walled tubular shaft with a heating chamber D arranged between an outer jacket tube and an inner jacket tube, and the tubular drum surrounding the tubular shaft is equipped with heating chambers E and that as through the heating chambers E, D in the forced circulation heating medium is provided to a temperature below the decomposition temperature of the asphalt or bitumen liquid is provided. Suitable heating media and heat transfer media are, for example, suitable thermal oils that are heated to a temperature not exceeding 250 ° C. for recycling asphalt. This heating temperature precludes any decomposition and change in the binder contained in the asphalt mixture, such as bitumen. Any indirect overheating of the material to be processed is avoided by the indirect heating and heating of the fresh material or asphalt opening via the contact heat emitted by the drum and the tubular shaft. Since no hot gases flow through the material to be processed, no dust is removed. The heating of the heating mixer conveyor according to the invention takes place on the one hand from the inside with the aid of a sufficiently large double-walled tubular shaft and from the outside enclosing the mixing chamber Heating chambers of the drum formed heating area.

Both street asphalt and mastic asphalt can be produced continuously with the device according to the invention. Starting material can be fresh material and / or old material, i.e. Road asphalt departure.

The recycling material with the device according to the invention is suitable both for direct reinstallation and as an excellent addition of raw materials in large asphalt mixing plants. This means that road asphalt demolition can be completely and fully recycled. The device according to the invention thus makes a contribution to environmental protection, there are large waste dumps and the recycling takes place without environmental pollution by gases and dust.

In order to achieve good comminution and thorough mixing of the demolition material, the tubular shaft as a conveying element is also designed as a comminuting and mixing element by means of specially shaped blades or paddles attached on the outside. According to a preferred embodiment, on the outer casing tube of the tubular shaft at the beginning of the tubular shaft in the region of the filling opening of the drum and at the end of the tubular shaft in the region of the outlet opening of the drum, worm blades with a conveying effect are fastened and in the area in between, preferably in alternating sequence, spade-shaped paddles and V -shaped paddles attached for mixing and crushing. AI 1 e ^■ Paddles and paddles are provided in a helical arrangement on the outer casing tube. The heating mixer conveyor according to the invention is intended to enable a long dwell time of the break-up material to completely carry out the slow melting and sufficient comminution. For this reason, for the conveyance of the demolition material in the heating mixer conveyor, ie in the drum, screw blades or worm blades are provided only in the entrance area and in the discharge area, while in the entire central part the chunks of the demolition material are now and then Fly here, crushed, warmed and only slowly conveyed on. The spade-shaped paddles are used for kneading, the toothed paddles serve as impact tooth paddles, in particular in cooperation with webs which act as breaking teeth on the inside of the drum and engage in the V-shaped paddles to break up and crush the material. The device according to the invention thus also counteracts a new formation of lumps. - Even larger stones as foreign bodies ^' are broken in the heating mixer conveyor and adapted to the recycling material.

In order to convey the material carried up a little further when the tubular shaft is rotated, in a further embodiment of the device it is provided that the drum with the tubular shaft inclines from the inlet opening to the outlet opening from the horizontal by a small angle CC of approximately I to 3 ° with a gradient is arranged. A slight incline is sufficient to achieve the desired conveyance of the material carried up, but at the same time to ensure that the material remains in the heating mixer conveyor for as long as possible, i.e. is slowly and continuously conveyed through the drum to achieve the longest possible heating-up time. In particular, it is also provided that the drum with a tubular shaft is designed to be adjustable from the horizontal, for example by means of a spindle or other mechanical or hydraulic lifting elements, such as lifting cylinders. According to the invention, the entire heating mixer conveyor can therefore be adjusted in a desired inclined position in order to force a small feed by the material falling freely. The mixing and kneading blades and paddles, which are attached to the tubular shaft, support the feed while avoiding lump formation.

In order to make the mixing chamber of the drum between the tubular shaft and the drum inner wall accessible for inspection or repair at any time, according to a further proposal of the invention, at least part of the upper drum is designed to be hinged. In particular, it is provided that the drum in the horizontal is divided into the longitudinal extent and is formed in the areas between the inlet opening and the outlet opening with an overhead separate half-shell, which is articulated and hinged along one side in the longitudinal extension of the drum and hinged to the lower remaining half-shell of the drum. The half-shell can be opened mechanically or hydraulically, for example, a hydraulic device with a lifting cylinder can be provided, which is connected to the half-shell to be opened via tilting bearings.

To the outlet from when heating. To allow the break-up material to be generated, at least one vapor outlet, e.g. an outlet pipe or the like, is provided on the top of the drum.

In the event that the demolition material to be recycled still needs to be added for later re-use, this, for example bitumen, can be dosed in small quantities hot or cold in comminuted form with the demolition material directly into the inlet opening of the drum. However, it is also possible, according to a further proposal of the invention, to equip the drum with a separate feed device for binders, in particular liquid bitumen, for example an atomizing device. This facility is preferably near the end of discharge, i.e. the outlet opening of the drum, where the processed material arrives in shredded form.

For the rotatable mounting of the tubular shaft as a conveying member in the drum, it is proposed that a tubular shaft end piece is inserted into the inner casing tube at each end of the tubular shaft, with which the tubular shaft is supported in end-side end shields which close the drum ends.

For the supply of the heating medium in the tubular shaft, a pipeline is proposed, which lies coaxially through the tubular shaft and in the region of the inlet opening of the drum Rohrwel 1 end piece is guided and is connected at the end in the region of the outlet opening of the drum via a passage with the heating chamber of the tubular shaft. Thus, the heating medium can flow back through the heating chamber through the pipeline guided inside the tubular shaft from the rear end of the tubular shaft and can be discharged again via a passage connecting the heating chamber with an outlet line. In order to ensure a continuous return and delivery of the heating medium in the heating chamber of the double-walled tubular shaft, it is proposed to arrange a coil in the tubular heating chamber formed by the outer jacket tube and the inner jacket tube. This spiral or swirl guide causes a forced delivery of the heating medium in the desired direction during the rotation of the tubular shaft.

Two heating circuits are preferably provided for uniform heating of the drum. For this purpose, it is proposed that the heating chambers of the drum lying below the horizontal central plane of the drum are connected in one heating medium circulation with a pipeline and a return line and the heating chambers lying above the horizontal central plane are connected in a further heating medium circulation with a pipeline and a return line are. In order to include the hinged half-shell of the drum in the upper heating medium circulation, the heating chamber formed in the movable half-shell is connected to the adjacent heating chambers by means of an elastically movable pipe loop running outside the drum.

It is important for the operation of the device according to the invention that the temperature of the heating medium, for example thermal oil, must be kept very constant, in all flow areas both in the tubular shaft and in the drum, in order to avoid deformations of the device parts due to uneven thermal expansion. It is advisable to provide temperature control for the heating medium.

The invention is exemplified in the drawing. It Figure 1 shows a longitudinal section in view through the heating mixer conveyor with drum and tubular shaft

FIG. 2 shows the cross section ON according to FIG. 1 with the drum upper part additionally opened

3 shows the cross section XY according to FIG. 1

Figure 4 is a schematic view of the heating mixer conveyor according to Figure 1 with lifting device

Figure 5 shows a schematic cross section through drum with tubular shaft and paddles perpendicular to the longitudinal axis

Figure 6 schematically shows a top view of a V-shaped paddle

Figure 7 View of a recycling plant with heating mix conveyor

8 shows a cross section analogous to FIG. 2 with demolition material al.

1 to 3 show an embodiment of a heating mixer conveyor according to the invention for recycling street asphalt in partially schematic cross sections. The mixing chamber V is located between the inner wall of the drum 3 and the tubular shaft 11. The cylindrical drum 3 is closed at the end with the two end shields 1, 2, which have the bearing bushes la, 2a centrally around the longitudinal axis H, in which the tubular shaft is guided and is stored. The drum as well as the tubular shaft 11 are divided into three sections, the entrance area with the inlet opening F for the material to be recycled, the middle area for heating, crushing and mixing and the Discharge area with the outlet opening G for the recycling material.

The drum 3 is formed horizontally divided in the longitudinal extent to its longitudinal axis H. In the middle part of the drum, the upper part of the drum is designed as a hinged half-shell 3b. The edge-side drum parts 3c and 3d and the lower half-shell 3a are firmly connected to one another. All areas of the drum are heated. For this purpose, the drum walls are double-walled with the heating jackets 4 and form cylindrical shells with the heating chambers E, i.e. Ea in the lower and Eb, Ec, Ed in the upper half of the drum. The heating medium, e.g. Oil, via pipes not shown in the direction of arrow S, the heating chambers Ec, Eb, Ed of the upper half of the drum and R to the heating chambers Ea of the lower half of the drum and at the end, as indicated by the arrows T and U, removed and the heating unit for reheating forwarded. The discharge pipe 21 for vapors and vapors is provided in the upper drum shell 3b against the discharge end of the drum. To inject liquid bitumen, the injection device 25 is provided near the discharge end of the drum, with which the missing binder can be metered directly into the mixing chamber. The hinged drum shell 3b is mounted on both sides between the flange support pieces 5, 6, which are connected to the tilting bearings 22, on which hydraulically actuated lifting cylinders 23, which are supplied by a hydraulic unit 26, are articulated. Figure 3 shows the lifting cylinder in the extended state, i.e. in the closed state of the drum, while Figure 2 shows the lifting cylinder 23 in the retracted state, i.e. shows in the opened state of the drum. The heating oil lines from the heating chamber Ec to the heating chamber Eb and from the heating chamber Eb to the heating chamber Ed are designed as elastically movable pipe loops, which are not shown here, and bridge the flange support pieces 5, 6 from the outside.

The drum 3, ie all parts 3a to 3d of the drum, is covered on the outside with a thermal insulation layer 24. The tilting device 22, 23, 26, the drum shell 3b is, for example, attached to the stands 14, 15, which simultaneously support the drum.

The double-walled, heatable tubular shaft has the outer jacket tube 11 and the inner jacket tube 10, between which the tube-shaped heating chamber D is created, through which the heating medium is guided. On the outer casing tube 11, the crushing and conveying elements, such as worm blades 19, spade-shaped paddles 20, fang-tooth paddles 20a and V-shaped press paddles 20b, see FIG. 6, are attached. The material to be processed is heated via the contact heat on the inside of the drum and the outside of the outer casing tube 11 of the tubular shaft. At the two ends of the double-walled tubular shaft 10, 1, a tubular shaft end piece 7, 8 is inserted into the inner jacket tube, the outwardly projecting end of which forms the bearing shaft in the end shields 1, 2 of the drum. These tubular shaft end pieces 7, 8 are each firmly connected to the inner casing tube 10 by means of supporting cross members 9. The tubular shaft end pieces also serve to transport the heating medium. For this purpose, the pipeline 12 is provided, which runs coaxially to the longitudinal axis H of the tubular shaft and leads from the rotor stuffing box 18 through the tubular shaft end piece 8 on the input side of the drum through the tubular shaft 11, 10 to the tubular shaft end piece 7. The rotor stuffing box 18 is fastened to the end shield 1 by means of the bracket 17. The tubular shaft 11 is driven by the gears 16 by a motor, not shown. The heating medium is now introduced in direction A through the rotor stuffing box 18 into the pipe 12, flows through the pipe into the pipe shaft end piece 7, see arrow B. The interior of the pipe shaft end piece 7 is connected via passage 71 to the heating chamber D of the pipe shaft . Through this passage, the heating oil flows into the heating chamber D and from here in the opposite direction of the recycling material back to the input side, ie to the tubular shaft end piece 8. Here, the heating chamber D is via a further passage 82 with an outlet line 82 provided in the tubular shaft end piece 8 connected via which the heating medium flows back into the rotor stuffing box 18 and exits here in the direction of arrow C and is fed back to the heating device.

In order to enable a uniform delivery of the heating oil through the heating chamber D, the schematically indicated swirl guide 13 is provided in the form of a spiral which continuously connects the walls of the outer jacket tube 11 and the inner jacket tube 10.

So that when the material is added in the direction of arrow F in the mixing space, the chunks and stones do not fly back or get stuck to the end of the drum in the area of the end shield 1, one of the worm blades 19 is arranged in opposite directions, likewise at the end of the drum. The crushing and conveying members 20, 20a, 20b are attached and arranged in a helically offset manner on the tubular shaft 11. With an inner diameter of the drum of, for example, 850 cm, an outer diameter of the drum of 1200 cm, an outer diameter of the tubular shaft of '450 cm and a drum length of 12 m, the heating mix conveyor can at a temperature of the heating medium up to a maximum of 250 ° C about 20 t each Recycle one hour of asphalt. Here, the tubular shaft is occupied with, for example, 8 paddles per circumference. A total of approx. 160 paddles and the snail wings are provided.

The paddles and wings are provided with wear layers on the work surfaces and edges, for example hard metal pads.

In order to achieve a high comminution effect, simple mixing paddles, for example spade-shaped paddles 20 and press paddles 20b according to FIG. 6, are provided in an alternating sequence of the gradients. The V-shaped ^' press paddles 20b, see FIG. 6, which are welded onto the top of the tubular shaft 11, for example, work with webs or projections or teeth which are welded onto the inside of the drum 3 20c together. The paddles 20 can have a suitable shape adapted to the material to be processed.

This is schematically shown in cross section in FIG

Interaction of V-shaped paddles 20b and the webs 20c shown on the drum inner wall, purely schematically.

In the figure 4 is a schematic front view of the Heizmischförderers 100 with drum 3 shown inlet for ^'the material F, G outlet opening, with a lifting device for tilting the Heizmischförderers. The inclination is at a very small angle oC from the horizontal I, so that the longitudinal axis of the tubular shaft runs under the drum with a slight slope and thus produces a low free-fall feed for the material to be conveyed. Here, the drum is mounted in the area of the outlet opening via a pivot point 30 and is adjusted at the other end in the area of the inlet opening by means of a lifting device, for example mechanically or hydraulically actuated spindle 23, which is guided between the plates 28 and 29.

In addition, the heating medium circulation in the upper and lower half of the drum is shown schematically. For the top one

Half of the drum, the heating oil at S is fed through a pipe, at the apex, and then near the

Te tion level by means of the two heating chambers Ec, Eb der

Drum parts 3c, 3b connecting pipe loop 31 in the

Heating chamber Eb of the hinged drum shell 3b initiated.

The forwarding from the drum shell 3b again takes place on

Peak of the heating chamber Eb by means of another

Pipe loop 32, which connects to the fixed upper heating chamber Ed near the parting plane, in order to leave this heating chamber Ed again at the apex with the return line. The heating oil supply in the heating chambers Ea of the lower one

Drum shell takes place alternately from the apex to

Lowest point in order to heat the drum as evenly as possible. FIG. 7 shows a plant for recycling road asphalt with a heating mixer conveyor 100 according to the invention. The task of opening the road M takes place via the conveyor 50 into the grinder 51 for a grain size of 1 to 40 mm. The ground material is in via the elevator 52 in _. metered the inlet opening F of the heating mixer conveyor. The Heizmischfδrderer is ^' fed by the thermal oil heater 54 via the pipes A, R and S and the thermal oil via the pipes C, T and U returned. If required, 25 hot bitumen can be added in fine doses via the injection device. The recycled directly reusable material comes from ^* em Heizmischförderer in the filling and loading silo 53rd

8 shows ^schematis' ch the cross section of

Heating mixer conveyor with opened drum half-shell for inspection and the filling volume with the material M to be recycled

Claims

1. Heating mixer conveyor for the continuous production of.

Road asphalt or Gu ^' ßasphalt by heating, crushing and mixing fresh material and / or ground road asphalt Au break in a directly or indirectly heated drum, containing a driven and rotating conveyor, a filling opening and an outlet opening, characterized in that the conveyor can be heated is designed as a double-walled tubular shaft (10, 11) with a heating chamber (D) arranged between an outer jacket tube (11) and an inner jacket tube (10) that the tubular drum (3) surrounding the tubular shaft (10, 11) with heating chambers (E) is equipped, and that as the heating medium in the forced circulation through the heating chambers (D, E) a liquid is provided which is heated to a temperature below the decomposition temperature of the asphalt or bitumen.

2. heating mix conveyor according to claim 1, characterized in that on the outer casing tube (11) of the tubular shaft at the beginning of the tubular shaft, in the region of

Filling opening (F) and at the end of the tubular shaft, in the area of the outlet opening (G) of the drum (3) worm blades (19) with conveying action and in the area in between, in alternating sequence, spade-shaped paddles (20) and V-shaped paddles (20a , 20b) are attached for mixing and crushing in a helical arrangement.

3. heating mixer conveyor according to claim 1 or 2, characterized in that on the inside of the drum (3) acting as a breaking tooth in the V-shaped paddles (20b) engaging webs (20c) are attached.

4. heating mixer conveyor according to one of claims 1 to 3, characterized in that the drum (3) with tubular shaft (10, 11) from the inlet opening (F) to the outlet opening (G) from the horizontal by an angle oC of about 1 ° to 3 ° is inclined with a slope to the outlet opening (G) is adjustable.

5. heating mixer conveyor according to one of claims 1 to 4, characterized in that the drum (3) divided in the horizontal plane in the longitudinal extent and in the areas between the inlet opening (F) and outlet opening (G) with an overhead separate half-shell (3b) - Is formed, which is hinged along one side in the longitudinal extension of the drum and hinged to the lower half-shell (3a) of the drum.

6. heating mixer conveyor according to claim 5, characterized in that for opening the half-shell (3b) a hydraulically with Hubzy ^' lindem (23) working device is provided which is connected via tilting bearing (22) with the half-shell (3b) to be opened.

7. heating mixer conveyor according to one of claims 1 to 6, characterized in that the drum is equipped on the upper side with at least one outlet pipe (21) for vapor vapor outlet.

8. heating mixer conveyor according to one of claims 1 to 7, characterized in that the drum is equipped with a feed device (25) for binders, in particular liquid bitumen.

9. heating mixer conveyor according to one of claims I to 8, characterized in that in the inner casing tube (10) of the tubular shaft at each end a tubular shaft end piece (7,8) is used, with which the tubular shaft in end-side end shields (1,2) of the drum is stored.

10. Heating mixer conveyor according to one of claims 1 to 9, characterized in that for the supply of the heating medium into the tubular shaft (10, 11), a pipeline (12) coaxially through the tubular shaft and the tubular shaft end piece (8) lying in the region of the inlet opening of the drum. is guided and is connected in the region of the outlet opening (G) of the drum via a passage (71) to the heating chamber (D) of the tubular shaft, and the heating chamber (D) at its area adjacent to the inlet opening (F) via a further passage ( 81) with an outlet line led through the tubular shaft to the outside. (82) is connected.

11. Heating mixer conveyor according to one of claims 1 to 10, characterized in that a coil (13) is arranged in the tubular heating chamber (D) formed by the outer jacket tube (11) and the inner jacket tube (10).

12. heating mixer conveyor according to one of claims 1 to 11, characterized in that the below the horizontal central plane of the drum (3) lying heating chambers (Ea) of the drum (3) in a heating medium circulation with a pipe feed line (R) and a return line ( U) are connected and the heating chambers (Eb, Ec, Ed) above the horizontal central plane are connected in a further heating medium circuit with a pipe feed line (S) and a return line (T), the ones formed in the hinged half-shell (3b) Heating chamber (Eb) is connected to the adjacent heating chambers (Ec and Ed) by means of an elastically movable pipe loop running on the outside of the drum.