DE19526495A1 - Thermally treating hydraulically bonded mineral fibre materials - Google Patents

Abstract

Glass, mineral or asbestos fibres, bonded by a hydraulic medium, are thermally converted by treatment in a stationary (10) or mobile plant, into which the material is charged (14) from a container or conveyor belt, passing into a storage bunker separated by a slide plate (11) from a treatment chamber (13) in which the charge is subjected to an electromagnetic radiation filed from a microwave generator which produces wavelengths in the range 10<-1> - 10<-6> m. At least part is in a region of an absorption max., so that the charge is heated, transforming the material from a fibrous state to, e.g. a granular state.

Description

The invention relates to a method for the thermal conversion of hydraulic setting agents bound construction u. Like-substances with fibers on a mineral basis such as Glass, rock or asbestos fibers; it also relates to a device for performing the Procedure.

The known fibrous materials are because of their special properties, low density, high Isolation ability, often used in construction. Facade panels or insulating components used in the wall and roof area of buildings both outside and inside and often exposed to external influences.

The fiber components of these components can come loose and as air-borne air contaminants are also inhaled, making them a health risk for Become humans and also animals. Due to the pointed shape of the fibers, these can become fix on the inner walls of the lungs and there the formation of tumors such as Trigger mesothelioma.

Therefore, these building materials must be disposed of in compliance with the greatest safety regulations. For this purpose, the materials removed under respiratory protection are wrapped in films, into one Landfill transported and deposited there.  

Whether the foils survive the transport undamaged depends on how carefully they are handled with the substances packaged in this way, causing the foils to leak and thus the danger An escape of such substances cannot be ruled out, which poses a risk living people now leads. The deposited substances remain unchanged in the landfill. This also leads to a potential hazard for future generations.

In order to render these fibrous building materials harmless, attempts have already been made to remove them to shred by means of complex mechanical comminution processes so that they without significant dangers can be reused as building materials or additives. To oscillating ball mills or drive-dynamic mills have been proposed. With these Mechanical processes break down the fibrous building materials, but they cannot fail to release straight fiber fragments in the dangerous length range, since experience has shown that the entire amount of fibers cannot be shredded to the extent that Cell damage must be excluded; rather, a certain amount of fiber remains in the Hazardous area. This proportion of insufficiently ground fibers leads to the fact that such mechanical preparations do not completely rule out hazards.

According to another proposal, the fibers are heated to high temperatures; lying there these temperatures are at least close to the melting point of glass or fiber Minerals in the range from around 900 ° C to 1200 ° C, with those from asbestos above about 1400 ° C. This results in melting with a change in the crystal structure loses its pointed shape and changes into granular structure, which makes it reusable as a building or aggregate without endangering.

The heat is transferred in a kiln by direct contact with the Flue gases, the furnace must be brought to the required temperature and the flue gases must also be removed. These smoke gases still cannot remove the converted fibers that are not in a subsequent flue gas cleaning be separated quantitatively, especially with the large amounts of distillate to be used Substantial amounts of flue gas are produced.

The task on which the invention is based is derived from this, a method and to propose a device for its implementation, in which the thermal Treatment is carried out independently of a combustion chamber, the for Treatment proposed facilities should be stationary or mobile, which is safe and allow economic transformation.

To solve this problem, a method according to the main claim is proposed; for the Device solve the characteristics of the subsidiary claims this task.

The respective advantageous developments or preferred embodiments describe the subclaims.

In order to heat the fibrous building materials, treatment in fields with electro magnetic radiation, the wavelengths of which are in the range from 10-1 m to 10-6 m, proposed, that includes the range of microwaves to infrared. Will be beneficial the frequency of the electromagnetic oscillation generating these radiation fields to the area of maximum radiation absorption due to the base material of the treated building material, this frequency from material to material can be different, but always in the case of hydraulically bound materials Dipole frequency of the water is bound. Due to the radiation field in the area of Absorption energy are excited to vibrate molecules, whose Corresponds to the intensity of the heating.

The electromagnetic field in the microwave range acts at least initially in the essential about dipole moments on the molecules, so that always water molecules containing hydraulically bound building materials are thereby heated. While with increasing heating and progressive calcination of the water content and thus the heating caused by this decreases, heat generation due to onset electrical conductivity via conductivity mechanisms, which then become stronger and stronger prevails. In the transition area between microwaves and infrared there is Energy conversion due to dielectric absorption, characterized by the dielectric Loss angle, before, in the short-wave range infrared radiation, however, the direct beam absorption.  

It goes without saying that the frequency of the electromagnetic fields towards the treating substance must be turned off.

It is true that the oscillation must be used to generate sufficiently high-energy radiation fields sufficient power is supplied to the generator, which ultimately in a power plant z. B. is generated by burning fossil fuels, but the flue gas passage is eliminated flow of the fibrous mixture, a discharge of suspended fibers from the ver driving is prevented.

The conversion advantageously takes place at reduced pressure, for which purpose the internal chamber pressure is reduced to below 0.5 bar (50% vacuum). Through this pressure reduction, the Reduced heat loss.

The reduced oxygen partial pressure suppresses oxidative processes, so that occurrence of voluminous gaseous combustion products is avoided. Of the Pressure when converting substances sensitive to oxygen, in particular those that would give off gaseous combustion products will therefore be reduced of the oxygen content significantly below the specified limit.

The metering of the energy transmitted via the electromagnetic radiation field becomes determined by the type and amount of fibrous portion in the material to be treated, the dose to be applied also from the final temperature to be reached and from the Material constants is determined.

The dose rate is the permissible (anode) power loss of the vibration Producer dependent, so that the dose ultimately over the period of exposure is specified.

The conversion process is advantageously carried out as follows: For example, when renovating a building resulting fiber-containing materials are usually with mortar, glue, paints, or the like. contaminated; after a rough sorting, they are placed in a chamber which is shielded electromagnetically, and in which the electro magnetic radiation field can be generated.  

Suitable radiation generators in the microwave range are magnetrons, the frequency of which the magnetic field in connection with the external resonator to a desired value can be brought up, while in the infrared range lasers, especially high energy lasers Find application where radiation fields from thermal radiators are also used can. These substances absorb radiation in this electromagnetic radiation field energy, its temperature rises.

The fibrous materials lose their fiber structure and above a temperature limit transform into a granular structure. Although this treatment doesn't work with that mechanical crushing in a mill is comparable, they correspond vice versa changed materials, for example, to those created by grinding: the pointed Fibers that penetrate the cell membrane and can thus mechanically damage cells rounded and granular due to the conversion and thus no longer pose a danger to cells because the fibers no longer have any tips.

Through this type of thermal treatment in an electromagnetic radiation field, like a microwave field or an infrared radiation field, a substance with new Surface structure created, the conversion so in a relatively short time and with low cost can be achieved. It comes down to the ones that arise Grain sizes do not adhere, because with the transition from fibrous to granular substances the healthy harmfulness is eliminated; they can be used again without hesitation, for example as Main component or aggregate of building blocks or slabs. Because many of these inorganic Fibers formed by silicates also bind the substances derived from them hydraulically ab, they are cement-like and are suitable as building materials or aggregates. It enables the process an economical preparation of fibrous materials, in particular those that contain asbestos and artificial mineral fibers for reusable construction also fillers.

The method is advantageous in a device with a cubic or cylindrical Container which has a closable filling opening and a closable outlet opening has, carried out, the filling and outlet openings being locked against one another, that only one of the two can be opened in the conversion operation.  

A sieve plate upstream of the outlet opening allows the passage to be separated, during the residue remaining on the sieve the microwave treatment again is subjected. The screen plate advantageously forms a vibrating screen with a drive with which coarse parts are retained for further treatment.

The motorized drive sets the vibrating screen in lateral movement, making smaller Particles pass through the sieve as passage, while coarse particles as residue on the sieve be held back. The vibrating screen is above the outlet opening sealing plate so that the residue always remains in the treatment room.

The side walls of the cubic treatment container are temperature resistant and at least one of the side walls is made of electromagnetic radiation non-absorbent material behind which is the electromagnetic vibration field generating radiator is located.

Such materials are, for example, quartz, glass, porcelain, earthenware or ceramics also melt basalt or similar linings with which at least the walls are clad can be that are not adjacent to the radiation source. For a microwave field an antenna coupled to the output of a vibration generator is used, the the power is emitted into the container via a horn or a parabolic mirror, which is preferably via waveguide to the output resonator of the vibration energy delivering vibration generator is coupled.

In the case of microwave fields, the antenna device does not become the microwave absorbing partition partitioned from the treatment chamber of the container, at infrared vibration fields, if necessary after their fanning out to adapt to the Container geometry, thanks to a partition that is permeable to infrared. That’s why Means for generating the radiation field are separated from the treatment chamber, so that Impairment of the vibration generator or the antenna device excluded the partitioning walls neither weaken the radiation nor penetrate Heat self-absorption.  

The energy is advantageously radiated into the treatment chamber from two sides. The other two, perpendicular to the "antenna wall", are also advantageous Walls made of a microwave or infrared non-absorbent material, so that the Can form radiation field unhindered. It is advantageous if directed against each other Radiators are provided, the material to be treated being advantageously circulated.

It goes without saying that shielding also prevents possible health damage to the personnel operating the system as well as - especially at the An use of microwaves - also to prevent radio interference.

In the case of a cylindrical arrangement, the treatment chamber is advantageously equipped with at least one radiation beams aligned transversely to the chamber axis, originating from parabolic antennas, penetrates, with intersecting beams of radiation intensify the action. With cubic Parabolic antennas can also be used, but here is the one Use of horn blowers possible.

The treatment system is also particularly suitable for the cylindrical arrangement mobile use; for this purpose, the treatment chamber is pre-set in a treatment container see, which is arranged on the chassis of a treatment vehicle. To the treated A receptacle is provided so that it can be emptied well and stored safely which can also be designed as a removable container. Through this training in ensured in a simple manner that the thermal treatment of the resulting masses does not occur a full receptacle must be interrupted.

The goods to be treated are taken into consideration taking the necessary precautionary measures Dust and released fibers are filled in the treatment container and in the Treatment tank provided treatment chamber under the thermal treatment pulled.

After completion, the largely (possibly still hot) granular masses are combined into one Transfer container transferred. This is advantageously achieved in that the treatment Solution container is pivoted into an emptying position, so that the treated material under Gravity in the receptacle "falls".  

In this case, a transfer channel is advantageously provided, which from the receptacle after opening it by swinging open a filling flap or moving one Filling lid can be extended to the position required for emptying the treatment container is. This pivoting of the treatment container is advantageously locked so that a Panning can only be triggered when there is no electromagnetic energy in the treatment tank is engaged.

It is advantageous if this transfer channel with sufficient positive locking to the Creates the emptying opening of the treatment container. This will on the one hand be a clean and largely dust-free transfer of the treated goods from the treatment container to the Receiving container reached, and on the other hand there is the possibility of the treatment lid closing the container when the treatment is pivoted into the emptying position Lock container so that opening is only possible if the transfer channel fits properly against the emptying opening of the treatment container.

The essence of the invention will be explained in more detail with reference to the execution examples shown in Figures 1 to 8; show

Fig. 1 Stationary plant for the treatment of fibrous substances, filling, schematic vertical section;

Fig. 2 Stationary plant for the treatment of fibrous substances, emptying; schematic vertical section;

Fig. 3 mobile system for the treatment of fibrous substances, schematic representation, filling and treatment position;

Fig. 4 mobile system of Figure 3, preparation position for emptying the treatment container.

Fig. 5 mobile system of Figure 3, transfer of the treated masses in the transport container.

Fig. 6 Mobile system for the treatment of fibrous substances, alternative embodiment;

Fig. 7 Mobile system for the treatment of fibrous materials according to Fig 6, view from behind, system in the working position.

Fig. 8 mobile system for the treatment of fibrous materials according to Fig. 6, view from behind, plant ready position.

Fig. 9 mobile system for the treatment of fibrous substances, schematic representation, filling and treatment container part in section;

Fig. 10 Mobile system according to FIG 9, the treatment container part in radial section with a hinausschiebbaren residual and waste container.

Fig. 11 Mobile system according to FIG. 9, the treatment container part in radial section with a postponed residual and waste container in emptying position.

Fig. 1 shows a stationary system ( 10 ) with a cubic treatment chamber ( 13 ) for receiving material to be treated with an upwardly open filler opening ( 14 ), so that the material to be treated directly from a delivery vehicle ( 21 ) with a corresponding receiving container ( 22 ) can be introduced into the treatment chamber ( 13 ) from a container or via a conveyor belt.

The introduced material ( 2 ) reaches a pre-bunker, which is initially closed off from the treatment chamber ( 13 ) by the shut-off plate ( 11 ). To fill the treatment room ( 13 ), the shut-off plate ( 11 ) is withdrawn so that the material ( 2 ) can fall into the treatment chamber ( 13 ).

After the treatment chamber ( 13 ) is filled, its filling opening ( 14 ) is closed with the shut-off plate ( 11 ) and the microwave generator ( 19 ) is brought to power, the power required for generating a microwave field is disengaged and into the treatment chamber ( 13 ) initiated.

Under the action of the electromagnetic field, the material in the treatment chamber ( 13 ) heats up to the necessary treatment temperature. After the action of the microwave field has ended, the microwave generator ( 19 ) is shut down and the treated material, which has become granular or powdery like powder, is drawn off; for this purpose the base plate ( 12 ) of the treatment chamber ( 13 ) is opened so that the treated material can run out. An inserted sieve plate ( 14 ) retains the coarse fraction still to be treated as a residue, which remains in the treatment chamber ( 13 ).

The passage collects in the outlet bunker ( 17 ) as a reusable building material or aggregate ( 9 ) which - in its structure is no longer fibrous and is a health hazard - open via a filling dome ( 25 ) into the receptacle ( 24 ) of a transport vehicle ( 23 ) can be deducted and sent for further processing.

FIGS. 3, 4 and 5 show a mobile treatment plant in different Trt ungsphasen with a treatment vessel (30) with chassis (31) having a (32) provided with chassis wheels and a driving and control cab (33). On the chassis ( 31 ) a treatment container ( 35 ) is arranged, below which treatment container ( 35 ) the generator ( 34 ) for the electromagnetic field energy is provided, which is connected via line ( 34.1 ) to the motor of the treatment vehicle ( 30 ) coupled power supply (it goes without saying that a connection to an external power supply can also be provided). On the chassis 31 further stamps ( 31.1 ) are provided, the upper ends of which have bearings ( 31.2 ), in which pivot axes of the treatment container ( 35 ) are mounted so that the container from the filling and treatment position ( Fig. 3) to the emptying position ( Fig. 5) can be pivoted.

For pivoting, swivel bends ( 35.1 ) are provided, which cooperate with swivel drives ( 34.2 ) provided on the energy generator, these being locked in such a way that the treatment container ( 35 ) can only be swiveled when no electromagnetic energy is fed into the treatment container. A drive ( 37 ) is also provided on the swivel arch ( 35.1 ) with which the lid ( 36 ) of the treatment container ( 35 ) can be opened, specifically for filling and emptying. Here, too, a lock is provided such that the treatment container ( 35 ) can only be opened if no electromagnetic energy is fed into the treatment container ( 35 ).

On the chassis ( 31 ) of the treatment vehicle ( 30 ) there is also a receptacle ( 40 ) into which the material that has become granular due to the thermal treatment is transferred. In order to ensure a sufficiently dust-free transfer of this (possibly still hot) goods, the receptacle ( 40 ) has a flap or a displaceable closure cover ( 41 ) which is opened for transferring this goods.

After opening this flap or the closure cover, a transfer channel ( 42 ) is extended ( FIG. 4), which lies against the emptying opening of the treatment container ( 35 ) with a sufficient positive fit. It is advantageous if the transfer channel ( 42 ) cooperates with an unlocking of the lid ( 36 ) so that the opening of the lid ( 36 ) in the emptied position ( Fig. 5) treatment container ( 35 ) is only possible if the advantageously arcuate transfer channel ( 42 ) is properly in its sealing position.

FIGS. 6 to 8 show an alternative embodiment of a treatment vehicle (50) with mounted on its chassis (51) with a chassis with wheels (52) and driving and control cab (53) treatment plant with a (not shown here in detail) treatment chamber contains a treatment container ( 55 ) which is filled directly with delivery material ( 54 ) via a conveyor system with the material to be treated.

Fig. 9 shows a mobile system for the treatment of fibrous materials ( 30 ) with a schematic representation of the filler ( 40 ) and treatment container part ( 35 ) in an axial section.

The treatment container ( 35 ) is advantageously assigned two microwave generators and loaders ( 13 ) which are each supported by two parabolic antennas ( 13.1 ).

The fiber-containing substances are filled into the treatment container ( 35 ) through the opening of a radially displaceable flap ( 36 ). The substance to be treated is caused by the air circulation, which is generated by a motorized blower ( 40.1 ), and through a channel ( 42.1 ) whose outlet opening is located below the treatment container ( 35 ), in a wired state. The treated substance can then be sucked up on the top and filled into the filling container ( 40 ) through a channel ( 42 ).

Waste and residues are optionally introduced through a sliding and tiltable flap ( 35.2 ) which is inserted below the treatment container ( 35 ). This flap is advantageously the lower part of the treatment container ( 35 ).

Fig. 10 and Fig. 11 show a mobile system according to Fig. 9, the treatment container part ( 35 ) is equipped in radial section with a sliding out residual and waste container ( 35.2 ).

The displaceable and tiltable flap ( 35.2 ) which is arranged below the treatment container ( 35 ) can be pushed out, tilted, emptied and cleaned relatively easily.

FIGS. 10 and 11 also show the frontal views of the parabolic antennas and the microwave device (13) in a mobile system according to Fig. 9. Furthermore, the air channel (42.1) and advantageously a motor airflow generator (40.1), respectively.

Claims (23)

1. Process for thermal conversion with hydraulically setting agents bound construction u. The like. Fabrics with mineral-based fibers such as glass, rock or asbestos fibers, characterized in that the fibrous substances in a treatment chamber in an electromagnetic radiation field, with wavelengths in the range of 10-1 m to 10-6 m, of which at least one Part is in the range of an absorption maximum, exposed and heated so that the fibrous structure is dissolved. 2. The method according to claim 1, characterized in that the heating in one Microwave radiation field is carried out. 3. The method according to claim 1, characterized in that the heating in one infrared radiation field is carried out. 4. The method according to claim 1, 2 or 3, characterized in that the to be treated Building materials are introduced in portions into a treatment chamber and removed after treatment are pulled, the residence time of the material in the treatment chamber reaching temperature taking into account the available power of the corresponds to the electromagnetic radiation field. 5. The method according to claim 1, 2 or 3, characterized in that the to be treated Building materials are continuously guided through the radiation field, reducing the speed the passage of the material through the area of the field of the temperature to be reached taking into account the available power of the radiation field.   6. The method according to any one of claims 1 to 5, characterized in that the Conversion at negative pressure, preferably below 0.5 bar (<50% vacuum) lowered chamber pressure is made. 7. Apparatus for carrying out the method according to one or more of the preceding claims for converting fibrous building materials bound with hydraulically setting agents, in particular those based on minerals such as glass, rock or asbestos fibers with thermal influence, characterized in that a treatment chamber ( 13 ) is provided, into which the material to be treated is filled, to which a generator for electromagnetic vibrations via a radiation transmitter is connected from one side so that an electromagnetic radiation field is formed in the treatment chamber ( 13 ), the treatment chamber ( 13 ) is provided with a filling opening and with an outlet opening, which can be closed with gate valves ( 11 , 12 ; 36 ), the device as a whole being provided with a screen cover to prevent unwanted radiation of electromagnetic energy. 8. An apparatus for carrying out the method according to one or more of the preceding claims for converting fibrous building materials bound with hydraulically setting agents, in particular those based on minerals such as glass, rock or asbestos fibers with thermal influence, characterized in that a container ( 10 ; 35 ) is provided with a treatment section which passes through the material to be treated, to which a generator for electromagnetic vibrations via a radiation generator is connected from one side in such a way that an electromagnetic radiation field is formed in the treatment section, the treatment chamber ( 13 ; 35 ) has an inlet and an outlet through which the material to be treated is introduced and drawn off, the inlet and outlet being provided with locks and the device as a whole provided with a shielding cover to prevent undesired radiation of electromagnetic energy is. 9. Apparatus according to claim 7 or 8, characterized in that the container ( 13 ; 35 ) or the treatment section in the basic form has a cubic cross-section, and that its walls are temperature-resistant and at least one of the walls is designed to be permeable to the electromagnetic radiation used . 10. The device according to claim 7 or 8, characterized in that the container ( 13 ; 35 ) or the treatment section in the basic form has a cylindrical cross section, and that its walls are temperature-resistant and at least one of the walls is designed to be permeable to the electromagnetic radiation applied . 11. Device according to one of claims 7 to 10, characterized in that the outlet of the treatment chamber or the treatment section of the treatment container ( 13 ; 35 ) has a sieve ( 14 ), which is preferably designed as a vibrating sieve. 12. Device according to one of claims 7 to 11, characterized in that the side or side wall of the treatment container ( 13 ; 35 ) associated with the antenna or the radiator with the treatment chamber or treatment section made of a material which does not absorb the electromagnetic radiation, preferably from Quartz, glass, chamotte, ceramics or the like is formed. 13. The device according to one of claims 7 to 12, characterized in that the treatment chamber or the treatment section of the treatment container ( 13 , 359 ) is provided with a vacuum device, the treatment chamber or the treatment section being vacuum-tight lockable / lockable, and wherein a filter ( 3 ) is preferably provided in the suction of the vacuum device. 14. Device according to one of claims 7 and 9 to 13, characterized in that a drive ( 10 ; 37 ) is provided which cooperates with the shut-off plates ( 11 , 12 ; 36 ) of the filling or outlet opening in such a way that they mutually are locked. 15. The device according to one of claims 7 to 14, characterized in that the treatment chamber or the treatment section in a treatment container ( 35 ) of a treatment vehicle ( 30 ) is provided. 16. The apparatus according to claim 15, characterized in that the vibration generator ( 34 ) is also provided on a vehicle, preferably on the same treatment vehicle ( 30 ), with a power generator that can be driven by the drive motor of the vehicle or a for supplying energy to the vibration generator ( 34 ) connection ( 34.1 ) which can be connected to an electrical supply network is provided. 17. The apparatus according to claim 15 or 16, characterized in that the treatment container ( 35 ) is designed such that it can be pivoted about a horizontal axis and, after completion of the treatment of the material present in the treatment chamber of the treatment container ( 35 ), pivots with the outlet opening above a filling opening a receptacle ( 40 ) for the treated material for transferring the treated material, the pivoting drive ( 35.1 , 34.2 ) being locked with the vibration generator in such a way that the pivoting can only be triggered when there is no electromagnetic energy from the vibration generator in the treatment chamber is fed. 18. The apparatus according to claim 17, characterized in that the chassis ( 31 ) of the treatment vehicle ( 30 ) has substantially vertically aligned posts ( 31. 1 ), the upper ends of which have the pivot bearings ( 31.2 ) for the treatment container ( 35 ). 19. The apparatus according to claim 17 or 18, characterized in that the treatment tank ( 35 ) is provided with an approximately 120 ° swivel arc ( 35.1 ) which cooperates with a drive wheel ( 34.2 ), the drive for this drive wheel ( 34.2 ) cooperates with the vibration generator ( 34 ) such that the vibration generator can only be put into operation when the treatment container ( 35 ) is in the working position ( Fig. 3). 20. Device according to one of claims 15 to 19, characterized in that the emptying opening of the treatment container ( 35 ) is closed with an openable flap ( 36 ) which can be opened by means of a drive ( 37 ), preferably the drive ( 37 ) such is locked with the vibration generator ( 34 ) that the vibration generator can only be put into operation when the treatment container ( 35 ) is in the working position ( Fig. 3). 21. Device according to one of claims 15 to 20, characterized in that a receiving container ( 40 ) is provided, in the treated material from the treatment container ( 35 ) is transferred. 22. The apparatus according to claim 21, characterized in that the receiving container ( 40 ) has a with a pivoting flap or a sliding cover ( 41 ) closable filling opening. 23. The device according to claim 22, characterized in that the closable filling opening of the receptacle ( 40 ) has a transfer channel ( 42 ) which can be pivoted out after opening the pivoting flap or the sliding cover ( 41 ) and which preferably has the flap ( 36 ) of the treatment container ( 35 ) interacts in such a way that the flap ( 36 ) can only be opened when the opening of the transfer channel ( 42 ) lies in the region of the emptying opening of the treatment container ( 35 ).