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EP0149595B1 - Procédé et dispositif de régénération de sables de fonderie - Google Patents

Procédé et dispositif de régénération de sables de fonderie Download PDF

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Publication number
EP0149595B1
EP0149595B1 EP85890004A EP85890004A EP0149595B1 EP 0149595 B1 EP0149595 B1 EP 0149595B1 EP 85890004 A EP85890004 A EP 85890004A EP 85890004 A EP85890004 A EP 85890004A EP 0149595 B1 EP0149595 B1 EP 0149595B1
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EP
European Patent Office
Prior art keywords
sand
containers
container
rotary drum
foundry sand
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85890004A
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German (de)
English (en)
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EP0149595A3 (en
EP0149595A2 (fr
Inventor
Volker Dipl.-Ing. Godderidge
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kgt Giessereitechnik GmbH
Original Assignee
GSR SANDREGENERIERUNGSGESELLSCHAFT MBH
Kgt Giessereitechnik GmbH
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=25817474&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0149595(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from DE19843400656 external-priority patent/DE3400656A1/de
Priority claimed from DE19843400648 external-priority patent/DE3400648A1/de
Application filed by GSR SANDREGENERIERUNGSGESELLSCHAFT MBH, Kgt Giessereitechnik GmbH filed Critical GSR SANDREGENERIERUNGSGESELLSCHAFT MBH
Priority to AT85890004T priority Critical patent/ATE33105T1/de
Priority to DK212385A priority patent/DK157740C/da
Publication of EP0149595A2 publication Critical patent/EP0149595A2/fr
Publication of EP0149595A3 publication Critical patent/EP0149595A3/de
Application granted granted Critical
Publication of EP0149595B1 publication Critical patent/EP0149595B1/fr
Expired legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C5/00—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose
    • B22C5/18—Plants for preparing mould materials

Definitions

  • the invention relates to a process for the regeneration of foundry rubble sands which contain old sand mixtures with organic and inorganic binders, such as active and still burned bentonite and synthetic resins and optionally further sludge materials, such as hard coal dust, polystyrene, quartz fine dust, etc., in which process the crushed and optionally sieved foundry sand is used Removal of organic binders is subjected to thermal regeneration by heating and then to post-cleaning, in which binder residues adhering to the sand grains are mechanically removed from the grain surfaces, and a device therefor.
  • organic and inorganic binders such as active and still burned bentonite and synthetic resins and optionally further sludge materials, such as hard coal dust, polystyrene, quartz fine dust, etc.
  • green sand molds with green sand being a quartz sand with inorganic binders such as e.g. B. bentonite (clay) is understood.
  • the green sand is mechanically solidified with the addition of water by shaking to the required dimensional stability.
  • core pieces are inserted into the green sand molds, which are formed from quartz sand with the addition of organic binders, such as furan resins or phenolic resins.
  • the core gets its strength through chemical hardening of the binders.
  • the core pieces disintegrate due to the thermal load during the casting process, resulting in a mixture of green sand and core sand (“rubble sand”), which has to be processed if it is to be used again.
  • H.W. Zimnawoda and H. Jansen point out the possibility of regenerating foundry sands in a two-stage process, in which the main part of the clay residues is to be removed by wet regeneration in a first stage and in a subsequent thermal stage the organic parts of the bend agent are to be removed by annealing (750-820 ° C) should be completely removed (Zimnawoda loc. Cit. Page 597 and Jansen loc. Cit. Page 604).
  • Wet regeneration «water purification •
  • this known two-stage process can only be used satisfactorily if the so-called sludge content of the rubble sand is less than 4%.
  • slurries are the components of active bentonite (swellable bentonite), still burned bentonite (non-swellable bentonite), hard coal dust or so-called carbonaceous materials such as polystyrene, resins and Qu fine dust, understood.
  • Rubble sands but especially those with a sludge content of approx. 10% and more, are therefore regularly deposited in landfills. Due to the ever decreasing number of suitable landfills and the large amount of rubble sands, there are considerable space problems. This waste of raw materials is economically unacceptable due to the transport costs and landfill fees incurred and the expensive new sand that is only available to a limited extent. In addition, environmental problems arise due to the chemical components in the rubble sands, since these components can be washed out under the influence of the weather when it rains and there is a risk of groundwater contamination.
  • the invention has for its object to provide a method with which a complete regeneration of foundry rubble sands with a high sludge content is possible down to the quality level of new sand, so that the regenerate can be processed like new sand during core production.
  • This object is achieved in that the foundry sand is subjected to a dry pre-regeneration before the thermal regeneration, in which sludge adhering to the sand grains, in particular inorganic binders, are removed from the sand grains, and in that the removed sludge is then preferably removed by the foundry sand thus pre-regenerated a gas stream to be separated.
  • the three-stage regeneration process according to the invention mechanical pre-cleaning, thermal treatment, mechanical post-cleaning - surprisingly achieves a high-quality regenerated quartz sand that can be used indefinitely for all of the core manufacturing processes that occur.
  • the possibility of also reusing high-sludge-containing rubble sands after the regeneration according to the invention means that the dumping of these old sands on heaps described above and the consequent impairment of the environment is considerably reduced.
  • up to 75% recovery of high-quality regenerated quartz sand is possible. This enables considerable cost savings in the production of molds, since quartz sand regenerated by the method according to the invention is less expensive than new sand and, moreover, the landfill costs and freight costs can be saved.
  • the intensive mechanical pre-cleaning advantageously reduces the sludge content of the debris sand to be regenerated to 2 to 4%. This is preferably done by intensive grain-to-grain friction and / or by allowing the sand grains to impact, so that contaminants adhering to the quartz sand grain are rubbed off, ground off and / or blasted off.
  • the foundry sand is dried and preheated during the pre-cleaning by warm exhaust gas originating from the thermal regeneration. This ensures low energy consumption when carrying out the method.
  • the foundry sand is preferably dried to a water content of 0.5% in the pre-regeneration stage.
  • the invention also relates to a device for the regeneration of foundry rubble sands containing old sand mixtures with organic and inorganic binder parts, active and still burned bentonite and synthetic resins, and optionally further sludge materials, such as hard coal dust, polystyrene, quartz fine dust, etc., with an oven, preferably a fluidized bed oven which the foundry sand is heated for the purpose of annealing and a cleaning device downstream of the furnace for mechanical cleaning of the foundry sand, which is preferably designed as a rotating drum with an essentially horizontal axis and / or as a centrifugal wheel cleaner.
  • an oven preferably a fluidized bed oven which the foundry sand is heated for the purpose of annealing and a cleaning device downstream of the furnace for mechanical cleaning of the foundry sand, which is preferably designed as a rotating drum with an essentially horizontal axis and / or as a centrifugal wheel cleaner.
  • Such a device is known from DE-A-22 52 259.
  • the invention is further based on the object of developing a device of this type in such a way that, particularly using the method according to the invention, rubble sands with high sludge contents can be regenerated down to the quality level of new sand, so that the regenerate, like new sand, can also be processed in the core production .
  • the device according to the invention for the regeneration of foundry rubble sands should be largely prefabricated and easily transportable and should be able to be put into operation easily and in a short time at the place of use.
  • the furnace is preceded by a waterless mechanical pre-regeneration device, which is rotatable about a substantially horizontal axis rotating drum, in which baffle internals are preferably arranged and / or grinding media, such as balls, and / or as a centrifugal wheel cleaner is formed and that the units of the device are arranged in several transportable containers, connection flanges, intermediate pieces, couplings or plug connections for connecting the individual units of the device being provided in the area of the ceilings and / or the floors of the containers which can be placed congruently with one another.
  • a waterless mechanical pre-regeneration device which is rotatable about a substantially horizontal axis rotating drum, in which baffle internals are preferably arranged and / or grinding media, such as balls, and / or as a centrifugal wheel cleaner is formed and that the units of the device are arranged in several transportable containers, connection flanges, intermediate pieces, couplings or plug connections for connecting the individual units of the device being provided in the area of the ceilings
  • the dry-working pre-cleaning device is a centrifugal wheel cleaner and / or a cylindrical drum rotating about a horizontal axis, in which baffle internals in the form of sheets or grinding media, such as balls or the like, are preferably arranged or accommodated.
  • baffle internals in the form of sheets or grinding media, such as balls or the like are preferably arranged or accommodated.
  • intensive rubble sand comminution is achieved in the course of the pre-regeneration, which enables high efficiency in the thermal regeneration in the downstream furnace.
  • This mechanical pre-regeneration which is also possible for pure green sand, has the advantage over the devices that work with an air stream that the wear on the machine is lower and the self-stressing of the sand in the rotating drum does not lead to increased fine dust contents or to the destruction of the sand grain structure.
  • the necessary connections between the containers can be formed by intermediate pieces, quick couplings, plug connections and / or connecting flanges, the connections of which are congruent with one another.
  • the arrangement in containers creates a mobile system that can be easily brought on site and that can be installed and removed with little effort. In this way, it is possible for the first time to regenerate rubble sand cost-effectively using the service process.
  • Such a system is also particularly suitable for carrying out experiments, since as a rule the suitable conditions for a regeneration process must be examined on site for practical testing in a pilot process.
  • a line containing a blower opens axially, preferably coaxially, in the rotary drum and is connected to the furnace for supplying hot exhaust gas from the latter.
  • the line for the supply air for the fluid bed furnace is connected to the rotary drum for subsequent cleaning, the supply air being supplied through this rotary drum.
  • the containers sea containers have corresponding dimensions.
  • the units in particular the machines in the respective container, are mounted in a vibration-damped manner.
  • an elevator for feeding the rubble sand to be regenerated to the loading point provided in the upper container is arranged next to the stacked containers.
  • the device according to the invention can be accommodated in (used) sea containers. However, it is also possible to arrange the units in container-like containers. It is recommended according to the invention to provide that some of the units arranged in the containers, in particular the containers, the support structure for the rollers and the drives of the rotary drums and / or the fluidized bed furnace, at least partially in the frame, wall, floor and / or Ceiling construction of the affected containers are integrated.
  • the device according to FIG. 1 is arranged in three transportable containers up to III, which are congruent with one another.
  • Quick connections and connecting flanges are provided in the connection levels between the containers in order to connect the units provided in the individual containers to one another.
  • the connections are preferably congruent.
  • the containers used in the exemplary embodiment have the dimensions standardized for sea containers. For example, they are 12.19 m long, 2.44 m wide and 2.59 m high on the outside.
  • a feed silo 2 with a vibrator trough 3 arranged underneath In the upper container 111 there is a feed silo 2 with a vibrator trough 3 arranged underneath.
  • a filter system 22 is installed, which filters the exhaust air of the device before being discharged into the open.
  • a fluidized bed furnace 9 is provided in container III, in which the thermal treatment (second stage of the method according to the invention) of the rubble sand is carried out.
  • a buffer 12 and an output silo 18 are provided in container III.
  • a magnetic separator 4 In the middle container II, a magnetic separator 4, two cylindrical rotary drums 5 and 10, each with a horizontal turning axis 24, and a mechanical screening system 13 are arranged side by side.
  • Each rotary drum 5 and 10 is assigned a blower 6 or 23.
  • the rubble sand is pretreated for pre-regeneration before being placed in the fluidized bed furnace 9, in which the rubble sand is annealed for thermal regeneration.
  • the rotating drum 10 arranged in the longitudinal direction behind the rotating drum 5 serves for the subsequent cleaning of the rubble sand flowing out of the fluidized bed furnace 9.
  • a gas system 20 In the lower container I, a gas system 20, a compressed air system 21, a buffer store 7 with a pneumatic conveyor 8 arranged underneath, a controller 19, a further pneumatic conveyor 11 and several containers 14 for quartz sand, each with a grain size, are arranged next to one another Containers 14 located sand is withdrawn via a metering system 15 and a downstream mixing screw 16 is fed, which feeds the mixture to a further pneumatic conveyor 17.
  • the feed silo 2 in the upper container III is a conveyor 1, z. B. feeds an elevator, the hopper 25 is provided at the level of the lower container I near the ground.
  • a down pipe 26 leads downwards from the discharge silo 18, which ends approximately in the area of the bottom of the middle container II and to which further transport devices can be connected in order to be able to create the regenerate at the place of use.
  • the device accommodated in the three containers I, II and III only requires an electrical power connection in order to be ready for operation. After loosening the quick-release connections provided between the containers, the containers - each individually - are portable and can be brought to any location. This has the advantage, for example, that the regeneration of different rubble sands can be tested on site under practical conditions.
  • the container itself can advantageously be provided such that the individual units, in particular the machines (vibrator channel 3, magnetic separator 4, the blowers, the pneumatic conveyors, the screening system 13, the metering system 14, etc.) are vibration-damped within the respective container be stored.
  • the machines vibrator channel 3, magnetic separator 4, the blowers, the pneumatic conveyors, the screening system 13, the metering system 14, etc.
  • the first phase of the regeneration takes place in the form of a dry pre-cleaning in the first rotating drum 5.
  • conventional baffles are provided in the form of sheets, which determine the path of the incoming rubble sand and ensure further comminution.
  • 5 grinding elements in the form of balls or the like can be provided in the rotary drum, whereby a good comminution of the rubble sand is achieved.
  • the exhaust gas emitted by the fluidized bed furnace 9 is cleaned of dust particles etc. by the filter system 22 and fed to the hot air blower 6 in the line 29 symbolized by arrows, which blows the hot exhaust gases horizontally into the rotary drum 5, preferably coaxially with the axis of rotation 24.
  • the heat content of the exhaust gas from the fluidized bed furnace 9 can be used and the energy requirement of the overall system can be kept low.
  • the horizontally entering gas stream dries the rubble sand, for example, up to a water content of 0.5% and takes abrasion and floating particles with it, which are separated by the filter system 22 in the upper container 111 before the gas stream exits.
  • the sludge content z. B. reduced to 2 to 4%, in particular the binders in the green sand, namely the bentonites are separated and discharged from the quartz grain by grain-to-grain friction.
  • the shredded, pre-regenerated and preheated rubble sand falls into the buffer store 7 in the lower container 1, from which it is drawn off via the pneumatic conveyor 8 via a pipeline 28 and fed to the fluidized bed furnace 9 in the container 111.
  • the rubble sand is heated to a temperature of approximately 800 ° C., as a result of which the organic additives such as hardener and binder of the core sand burn. Bentonites that are still active are burned to death and lose their ability to swell. The combustion residues are discharged by air supplied by the fan 30 and filtered out in the filter system 22. The preferably cleaned exhaust gas from the fluidized bed furnace 9 is then fed via line 29 to the intake port of the hot air blower 6 assigned to the rotary drum 5 in the middle container II.
  • the rotary drum 10 corresponds in structure to the drum 5, also rotates about the horizontal axis 24 and preferably also has baffles and / or grinding media in the interior such as balls or the like.
  • Cooling air is fed to the rotary drum 10 horizontally and preferably coaxially to the axis of rotation 24 via a blower 23, which cools the sand in the drum 10 and at the same time discharges the combustion residues of the hardener and binder which have been abraded and ground by grain-to-grain friction.
  • the post-cleaning and the cooling of the regenerate take place simultaneously, so that voluminous cooling units for the regenerate can be dispensed with.
  • regenerate falls through a down pipe 31 into the pneumatic conveyor 11 and is conveyed through a pipe 32 into the intermediate storage silo 12 in the upper container 111.
  • the regrind is then classified by the sieve system 13 according to grain sizes and the grain fractions are temporarily stored in containers 14 in the lower container I.
  • the undersize (quartz sand dust etc.) is discharged directly via a down pipe 13 into containers (not shown) or other collecting or transport devices.
  • Quartz sand is drawn off from the containers 14 via the metering system 15 by means of sliders in the ratio corresponding to the desired grain composition of the regrind, mixed in the mixing screw 16 and conveyed by the pneumatic conveyor 17 via a line 34 into the discharge silo 18 in the upper container 111.
  • the regrind corresponding to the quality of new sand can be withdrawn from the discharge silo 18 via a down pipe 26.
  • the rubble sand processed in this three-stage regeneration device corresponds to new sand in all quality characteristics, so that the regenerate can be used for all common core manufacturing processes.
  • the original beta quartz of the new sand has been converted into alpha quartz due to the thermal treatment in the fluidized bed furnace 9, which is associated with an increase in volume of 0.86 to 1.30%.
  • such a conversion will occur when using new sand, so that the occurring Tensions and cracks in the sand surfaces of the mold and core areas are depicted in the cast surface and require an increased amount of cleaning.
  • the binding agents separated from the quartz sand granules are mainly excreted by flowing air or gas at several points of the device, namely at the magnetic separator 4, the rotary drums 5 and 10, the fluid bed furnace 9, the screening plant 13 and at the discharge silo 18.
  • the exhaust air entraining the binder particles or the exhaust gas of the individual units is conducted to the filter system 22 via a line-dotted line 36 and filtered there, so that largely dust-free exhaust air leaves the device.
  • the pilot plant shown in FIG. 2 can be used to carry out regeneration tests with old sands or old sand mixtures.
  • This system is mobile so that it can be transported to the centers of selected supply areas. In terms of workflow and process engineering, it corresponds to a large system according to the invention.
  • the pilot plant shown in FIG. 2 has sufficient procedural safeties so that the diversity of the existing old sand mixtures can be managed.
  • the pilot plant offers the possibility of further optimizing the design of large plants.
  • the pilot plant shown in Figure 2 is mounted in three containers with internal dimensions of 12020 x 2350 x 2390 mm. All pipelines and electrical supply and control cables are permanently installed within the individual containers, with the containers being connected to one another by means of removable intermediate pieces, quick couplings or plugs. Like the system shown in FIG. 1, the system according to FIG. 2 only requires a power connection, since a gas and compressed air supply is installed in the system itself.
  • the elevator 41 attached to the side of the containers IV, V and Vi has a feed hopper 42 and at its upper end an inlet pipe 43 leading into the upper container VI from above.
  • an old sand container 44 In the upper container VI an old sand container 44, a screw conveyor 45, a rotating drum 46 with a horizontal axis and four sand containers 47 (only two are visible) are accommodated.
  • a fan 48 In the middle container V, a fan 48, a cyclone separator 49, a further fan 50.a fluidized bed furnace 51 with an inlet pipe 52 attached to the side, a fan 53, a grain classifier 54 (Mogensensor), a blast wheel cleaner 55 with an outlet pipe 56 and a riser 57 are accommodated.
  • a grain classifier 54 Mogensensor
  • blast wheel cleaner 55 With an outlet pipe 56 and a riser 57 are accommodated.
  • a gas tank 90 In the lower container IV there is a gas tank 90, a screw conveyor 58 connected to the lower end of the cyclone 49, a rotary drum 59, pneumatic conveyors 60, 61 and 62, storage containers 63 for the various grain fractions, which are connected to a screw conveyor 64 on the outlet side, and another sand tank 65.
  • the rotary drum 46 is divided into three sections by internals arranged perpendicular to the drum axis.
  • the sand tubers are primarily crushed, which is supported by the use of rod-shaped grinding media.
  • This section is separated from the following section of the rotary drum 46 by a perforated plate, so that only free-flowing sand can get into the next section of the drum.
  • the old sand to be regenerated (rubble sand) is pre-regenerated by grain-to-grain friction, which is supported by a variable proportion of grinding media.
  • the third section of the rotary drum 46 works without grinding media and is mainly used to remove dust from the sand.
  • the sand contained in the rotary drum 46 is dried, dedusted and preheated by exhaust air from the fluidized bed furnace 51 which is conducted in countercurrent.
  • the fluidized bed furnace 51 is connected via a line 66 with a throttle valve 67.
  • the sand in the rotary drum 46 which is freed from the abraded fine particles by air sifting and preheated to a temperature of approx. 300 ° C. and has a sludge content of 3-4%, is fed through a pipe 69 at 52 into the fluidized bed oven 51, in with a sand temperature of 700-800 ° C is given up.
  • organic binder residues are completely burned and the sand is then fed through an outlet pipe 70 to the rotating drum 59 arranged in the lower container IV.
  • the rotating drum 59 has the same structure as the rotating drum 46 in the upper container VI and causes the sand to cool to approximately 120 ° C. the cleaning of the combustion residues and the deactivated bentonite as well as the dedusting of the sand.
  • Both the rotating drum 46 and the rotating drum 59 are designed so that the sand has a residence time of approx. 60 min at a capacity of 0.50 t / h. Has.
  • the sand emerging from the rotary drum 59 is brought by the pneumatic conveyor 60 via a line 71 into the sand container 47 having four chambers.
  • the pneumatic quest valves 72 arranged on the container 47 it can be selected in which of the chambers of the container 47 the sand supplied via the line 71 is released.
  • This makes it possible to fill one of the chambers of the container 47, while sand is fed to the centrifugal wheel cleaner 55 from another of the chambers via one of the sliders 73 and the downpipe 74.
  • the centrifugal wheel cleaner 55 is designed so that the cleaning process can be repeated four times during the filling time of one of the chambers of the container .47.
  • the sand passes through the container 65 and the pneumatic conveyor 62 and a sand conveying line 75 into another of the chambers of the container 47 or, after the after-cleaning has been completed, into a third of the chambers of the container 47.
  • the cleaned sand is now in the third chamber of the container 47, the previously filled chamber is now empty and the first chamber is filled with sand.
  • the sand cleaned by the centrifugal wheel cleaner 55 and contained in one of the chambers of the container 47 is brought into the classifier 54 via a line.
  • the regrind is broken down into the three most important grain fractions, the separating cuts being selected in such a way that all the usual grain distributions can be produced.
  • the individual grain fractions enter the three-part container 63 through downpipes 76 indicated by dash-dotted lines.
  • the desired quantities of grain fractions are removed from the container 63 via adjustable discharge metering slides 77 and mixed with the screw conveyor 64, the pneumatic conveyor 61 and a line 78 into the fourth Chamber of the container 47 promoted.
  • the regenerate with the desired particle size distribution can be drawn off from the container 47 via an outlet pipe (not shown).
  • the fluidizing air required for the fluid bed furnace 51 is supplied by the fan 53 which draws in fresh air.
  • the exhaust gas which heats up to 700 to 800 ° C. in the fluidized bed furnace 51, is fed to the rotary drum 46 via the exhaust gas line 66 and sucked out of it via a line 78 into a collecting line 79.
  • a second air flow originating from the centrifugal wheel cleaner 55 or from the classifier 54 is fed as cooling air to the rotary drum 59 via a line 80 and finally also reaches the collecting line 79.
  • the exhaust air passes through the fan 50 into the cyclone separator 49 and further via a line 81 to the clean gas fan 48 and finally via a line 82 to the outside.
  • the system is supplied with gas via, for example, a 900 kg tank 90 for liquid gas, which is equipped with all the necessary control and safety fittings.
  • One filling of the tank 90 is sufficient for an operating time of approximately 80 hours.
  • a compressor (not shown) is provided in the lower container IV, for example to the right of the container 65, which supplies conveying air for the pneumatic conveyors 60, 61 and 62 and furthermore the control air for the pneumatic slide valves 73 and 77.
  • the dust fraction separated in the cyclone 49 (if desired, two or more cyclones can also be provided) is conveyed via the screw conveyor 58 to a cellular wheel sluice and discharged through it from time to time.
  • FIGS. 3 to 5 The embodiment of the plant according to the invention shown in FIGS. 3 to 5 is also accommodated in three containers VII, VIII and IX arranged one above the other and is designed for a throughput of 7.5 t / h.
  • the silos for the rubble sand, the regenerate and the classifying unit are accommodated outside the container, which offers the advantage that the capacity of the plant is expanded to 15 t / h, for example, by installing a second regeneration unit (containers VII, VIII and IX) can be.
  • the sand containers 101 and 112 are constructed as a wall construction using the frame construction of the container IX.
  • the supporting structure for the accommodation of the rollers and the drives for the two rotary drums 107 and 109 are also the base construction of the containers VII and IX.
  • the fluid bed furnace 108 is integrated in the container VIII and likewise does not have its own support and wall construction.
  • the three containers VII, VIII and IX standing one above the other represent a complete regeneration unit, only the two elevators 105 and 145 and the pneumatic conveyor 150 are arranged externally.
  • An adjustable portion (for example 20 to 20%) of the sand conveyed through the line 103 is conveyed by a pneumatic conveyor 148, which is arranged in the lower container VII, into a sand container 106 at the top of the upper container IX, whereas the elevator 105
  • the rest for example 70 to 80% of the sand stream, is conveyed back into the sand container 101.
  • This arrangement ensures that the sand passes through the centrifugal wheel cleaner 102 three to five times before it reaches the rotary drum 107 for further treatment.
  • the rotary drum and its function correspond to the rotary drum 46 of the embodiment shown in FIG. 2.
  • the pre-regenerated rubble sand passes through a fluidized bed furnace 108 to burn off organic binder residues and then through a rotating drum 109 for subsequent cleaning.
  • Another pneumatic conveyor 150 arranged in the foundation 149 after the rotary drum 109 and below the lower container VII conveys the regenerated sand into the sand container 112 in the upper container IX. From this sand container 112, the sand reaches a second centrifugal wheel cleaner 151, in which a final cleaning process is carried out. From the centrifugal wheel cleaner 151, the completely regenerated sand passes through a vibro pipe 152 into a pneumatic conveyor 104 which conveys the regenerate, for example, to a mixture silo set up next to the containers VII, VIII, IX.
  • a device for classifying and mixing the individual grain fractions in the desired ratio which can have a structure similar to the corresponding device of the plant shown in FIG.
  • a fan 111 for the fluidized bed furnace 108 is also shown in the lower container VII.
  • the remaining air duct lines are only partially shown in Figures 3 to 5 for clarity.
  • the air flow or exhaust gas flow in the system shown in FIG. 5 corresponds in principle to that of FIG. 2.
  • the regenerated sand practically corresponds to new sand and it is possible to adapt these quality characteristics to the respective requirements by classifying and classifying them.
  • regenerate obtained in accordance with the invention is such that the same strengths as with new sand are possible when used in core making with the same binder additions. It is taken into account that regenerate yields of 75% of the amount of old sand are achieved, so that a mixture of regenerate and new sand of 75:25 can be compared with pure new sand.
  • the following overview summarizes the most important pollutants to be removed during sand regeneration. At the same time it is indicated which degradation is achieved in the individual regeneration stages.
  • the "mechanical 1" level corresponds to the treatment in the rotary drums 5, 46 and 107
  • the "thermal” process level corresponds to the treatment in the fluidized bed furnace 9
  • the "mechanical II” level corresponds to the treatment in the rotary drums 10, 59 and 109. (See table on page 11 f.)
  • the dry pre-cleaning is carried out in a rotating drum (FIGS. 1 and 2) or in a centrifugal wheel cleaner and a rotating drum (FIGS. 3 and 5).
  • a fluidized bed preheater can be provided in addition to the centrifugal wheel cleaner.
  • pre-cleaning rotating drum, centrifugal wheel cleaner with downstream rotating drum and centrifugal wheel cleaner, if necessary with fluid bed preheater
  • pre-cleaning rotating drum, centrifugal wheel cleaner with downstream rotating drum and centrifugal wheel cleaner, if necessary with fluid bed preheater
  • the supply air for the fluid bed oven alone is used for post-cleaning in a centrifugal wheel cleaner.
  • thermal regeneration takes place, can be preheated by a fluid bed cooler that cools the sand.
  • a centrifugal wheel cleaner which can be used in the context of the invention has a centrifugal wheel rotating about a vertical axis with radial strips, by means of which the sand supplied from above via a pipe coaxial with the axis of rotation is radially accelerated.
  • a fixed baffle ring with a V-shaped recessed baffle surface is arranged coaxially with the centrifugal wheel, whereby the sand radially accelerated by the centrifugal wheel strikes the lower half of the baffle ring, where it is deflected upwards to the upper half of the ring and is essentially deflected radially inwards, whereupon it the sand stream moving to the impact ring falls out of the centrifugal wheel cleaner downwards.
  • the sand is cleaned in this centrifugal wheel cleaner by impacting and rubbing the sand bodies against each other, the latter taking place in particular in the area where the sand stream crosses.

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  • Processing Of Solid Wastes (AREA)

Claims (20)

1. Procédé de régénération de sables de fonderie contenant des mélanges de vieux sable et de liants organiques et minéraux tels que bentonite active et surcalcinée et résines synthétiques et éventuellement d'autres résidus tels que poussière de carbone, polystyrène, poussière fine de quartz, etc., procédé dans lequel le sable de fonderie fractionné et éventuellement tamisé est soumis, pour l'élimination de liants organiques, à une régénération thermique par chauffage puis à une post-épuration dans laquelle les résidus de liant adhérant aux grains de sable sont enlevés mécaniquement des surfaces des grains, caractérisé par le fait qu'avant la régénération thermique le sable de fonderie est soumis à une prérégénération à sec dans laquelle les résidus, notamment des liants organiques, adhérant aux grains de sable, sont détachés de ceux-ci, et par le fait que les résidus détachés sont ensuite séparés, de préférence par un courant de gaz, du sable de fonderie ainsi prérégénéré.
2. Procédé selon revendication 1, caractérisé par le fait que, lors de la prérégénération à sec, un frottement grain contre grain est réalisé dans le sable de fonderie, par mélange et brassage de celui-ci autour d'un axe de préférence horizontal.
3. Procédé selon revendication 1 ou 2, caractérisé par le fait que, lors de la prérégénération, les grains de sable sont accélérés radialement et projetés contre une surface de rebondissement qui est fixe.
4. Procédé selon l'une des revendications 1 à 3, caractérisé par le fait que la teneur en résidus du sable de fonderie est ramenée à 2 à 4 %, lors de la prérégénération.
5. Procédé selon l'une des revendications 1 à 4, caractérisé par le fait que, pendant la prérégénération, le sable de fonderie est séché et préchauffé par du gaz chaud effluent provenant de la régénération thermique.
6. Procédé selon revendication 5, caractérisé par le fait que le sable de fonderie est séché jusqu'à une teneur en eau de 0,5 %.
7. Dispositif de régénération de sables de fonderie contenant des mélanges de vieux sable et de liants organiques et minéraux tels que bentonite active et surcalcinée et résines synthétiques et éventuellement d'autres résidus tels que poussière de carbone, polystyrène, poussière fine de quartz, etc., comportant un four (9, 51, 108), de préférence un four à lit fluidisé, dans lequel le sable de fonderie est chauffé aux fins du traitement de calcination, et un dispositif d'épuration disposé à la suite du four (9, 51, 108), pour épurer mécaniquement le sable de fonderie, ce dispositif d'épuration étant de préférence réalisé en tant que tambour rotatif (10, 59, 109) avec axe (24) sensiblement horizontal et/ou en tant qu'épurateur à roue centrifugeuse (151), caractérisé par le fait que le four (9, 51, 108) est précédé d'un dispositif de prérégénération mécanique, opérant sans eau, qui est réalisé sous la forme d'un tambour rotatif (5, 46, 107) tournant autour d'un axe sensiblement horizontal (24), dans lequel sont de préférence agencées des chicanes et/ou sont reçus des corps broyeurs, tels que des boulets, et/ou est réalisé sous la forme d'un épurateur à roue centrifugeuse (102), et par le fait que les ensembles d'éléments constitutifs du dispositif sont agencés dans plusieurs conteneurs transportables (I, II, III ; IV, V ; VI ; VII, VIII, IX), des brides de raccordement, pièces intermédiaires, accouplements ou raccords à emboîtement pour la liaison des différents ensembles du dispositif étant prévus dans la région des surfaces supérieures et/ou des fonds des conteneurs (I, III, II, IV, V, VI ; VII, VIII, IX) superposés avec recouvrement de contours.
8. Dispositif selon revendication 7, caractérisé par le fait qu'une conduite (29, 66) contenant un ventilateur (6) débouche axialement, de préférence coaxialement, dans le tambour rotatif (5, 46, 107), pour l'amenée de gaz effluents chauds provenant du four (9, 51, 108) auquel elle est raccordée.
9. Dispositif selon revendication 7 ou 8, caractérisé par le fait que la conduite (70) pour l'amenée d'aire allant au four à lit fluidisé (9, 51, 108) est raccordée au tambour rotatif (10, 59, 109) pour la post-épuration, cet air affluent étant acheminé au travers de ce tambour rotatif (10, 59, 109).
10. Dispositif selon l'un des revendications 7 à 9, caractérisé par le fait que les conteneurs (I à IX) possèdent des dimensions correspondant à des conteneurs maritimes.
11. Dispositif selon l'une des revendications 7 à 10, caractérisé par le fait que le dispositif agencé dans les conteneurs (I à IX) est indépendant de l'amenée d'énergie extérieure, exception faite de la fourniture d'énergie électrique.
12. Dispositif selon l'une des revendications 7 à 11, caractérisé par le fait que les ensembles, notamment les machines, sont montés d'une manière amortissant les vibrations, dans chaque conteneur concerné (I à IX).
13. Dispositif selon l'une des revendications 7 à 12, caractérisé par le fait que les silos (2, 12, 18), une installation de filtrage (22) et un four à lit fluidisé (9) sont agencés dans le conteneur supérieur (III), par le fait que les tambours rotatifs (5, 10) pour la pré-épuration préalable et la post-épuration, ainsi qu'une installation de tamisage (13), sont agencés dans le conteneur médian (II), et par le fait qu'une installation de gaz (20), une installation d'air comprimé (21), une commande centrale (19) ainsi qu'un dispositif doseur (15) suivi d'une vis mélangeuse (16) sont agencés dans le conteneur inférieur (I).
14. Dispositif selon l'une des revendications 7 à 12, caractérisé par le fait que le tambour rotatif (46, 107) pour la prérégénération mécanique à sec est agencé dans le conteneur supérieur (VI ; IX), que le four (51 ; 108) pour le traitement thermique est agencé dans le conteneur médian (V ; VIII), et que le tambour rotatif (59 ; 109) pour la post-épuration mécanique du sable de fonderie est agencé dans le conteneur inférieur (IV ; VII).
15. Dispositif selon revendication 14, caractérisé par l'agencement, à côté des conteneurs superposés (I à IX), d'un élévateur (1, 41, 105) pour amener le sable à régénérer au poste de chargement (trémie 2 ; 44 ; 101) prévu dans le conteneur supérieur (III, VI, IX).
16. Dispositif selon l'une des revendications 7 à 15, caractérisé par le fait qu'un épurateur à roue centrifugeuse (102) est prévu entre la trémie de chargement (101) et le tambour rotatif (107).
17. Dispositif selon l'une des revendications 7 à 16, caractérisé par le fait qu'un épurateur à roue centrifugeuse (55,131) est prévu entre le tambour rotatif (10, 59, 109) pour la post-épuration ultérieure et un dispositif classeur (13, 54).
18. Dispositif selon l'une des revendications 7 à 17, caractérisé par le fait que quelques uns des ensembles agencés dans les conteneurs (VII à IX), notamment les trémies (101, 112), la structure porteuse pour les galets de roulement et les systèmes d'entraînement des tambours rotatifs (107,109) et/ou le four à lit fluidisé (108), sont intégrés au moins en partie dans l'ossature, la structure de paroi, du fond et/ou de la surface supérieure du conteneur concerné (VII à IX).
19. Dispositif selon l'une des revendications 7 à 18, caractérisé par le fait que l'épurateur à roue centrifugeuse (102, 151) présente une roue centrifugeuse entraînée en rotation autour d'un axe vertical, dotée de nervures prévues sur son côté supérieur, et présente un anneau de rebondissement fixe dont la surface intérieure tournée vers la roue centrifugeuse comporte une dépression en forme de V, et par le fait que la roue centrifugeuse et agencée dans la région de la moitié inférieure de l'anneau de rebondissement.
20. Dispositif selon l'une des revendications 7 à 19, caractérisé par le fait que l'épurateur à roue centrifugeuse pour la prérégénération du sable de fonderie est suivi d'un échangeur de chaleur à lit fluidisé qui est raccordé à la conduite de sortie de gaz du four à lit fluidisé pour la régénération thermique.
EP85890004A 1984-01-11 1985-01-10 Procédé et dispositif de régénération de sables de fonderie Expired EP0149595B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AT85890004T ATE33105T1 (de) 1984-01-11 1985-01-10 Verfahren und vorrichtung zur regenerierung von giessereischuttsanden.
DK212385A DK157740C (da) 1985-01-10 1985-05-14 Fremgangsmaade og apparat til regenerering af stoebesand

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19843400656 DE3400656A1 (de) 1984-01-11 1984-01-11 Verfahren zur regeneration von giesserei-schuttsanden
DE3400656 1984-01-11
DE3400648 1984-01-11
DE19843400648 DE3400648A1 (de) 1984-01-11 1984-01-11 Vorrichtung und verfahren zur regeneration von giesserei-schuttsand

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EP0149595A2 EP0149595A2 (fr) 1985-07-24
EP0149595A3 EP0149595A3 (en) 1986-07-30
EP0149595B1 true EP0149595B1 (fr) 1988-03-23

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019130747A1 (de) * 2019-11-14 2021-05-20 WEBAC - Gesellschaft für Maschinenbau mbH Anlage und verfahren zum regenerieren von altsand, vorrichtung zum betreiben einer derartigen anlage sowie verwendung von abluft
FI131805B1 (fi) * 2023-03-22 2025-12-09 Resand Oy Menetelmä ja laitteisto tuorehiekan elvyttämiseksi

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Publication number Priority date Publication date Assignee Title
CH682986A5 (de) * 1990-03-08 1993-12-31 Fischer Ag Georg Verfahren zur chargenweisen Regenerierbehandlung von überwiegend tongebundenem Giesserei-Altsand.
CH682056A5 (fr) * 1990-03-08 1993-07-15 Fischer Ag Georg
ATE158731T1 (de) * 1990-06-28 1997-10-15 Krupp Ag Hoesch Krupp Verfahren zum regenerieren von giesserei- altsanden
IL97699A0 (en) * 1990-09-24 1992-06-21 Gaehler Franz Method and apparatus for reprocessing loose materials
DE4111726C2 (de) * 1991-04-10 1994-02-24 Kgt Giessereitechnik Gmbh Verfahren zur mechanischen Reinigung von Gießereialtsand
DE4316610A1 (de) * 1993-05-18 1994-11-24 Gut Gieserei Umwelt Technik Gm Öko-Sandregenerierung mech./pneum. im Chargenbetrieb

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DE1806842A1 (de) * 1968-11-04 1970-05-27 Wilhelm Schwiese Verfahren und Vorrichtung,um Giesserei-Altsande zu regenerieren
DE2252217A1 (de) * 1972-10-25 1974-05-09 Halbergerhuette Gmbh Verfahren zum rueckgewinnen von formgrundstoff
DE2252259A1 (de) * 1972-10-25 1974-05-09 Halbergerhuette Gmbh Einrichtung zum rueckgewinnen von giesserei-formgrundstoff
US4144088A (en) * 1977-01-19 1979-03-13 Kenzler Engineering Company, Inc. Process of reclaiming used foundry sand

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019130747A1 (de) * 2019-11-14 2021-05-20 WEBAC - Gesellschaft für Maschinenbau mbH Anlage und verfahren zum regenerieren von altsand, vorrichtung zum betreiben einer derartigen anlage sowie verwendung von abluft
FI131805B1 (fi) * 2023-03-22 2025-12-09 Resand Oy Menetelmä ja laitteisto tuorehiekan elvyttämiseksi

Also Published As

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DE3561928D1 (en) 1988-04-28
EP0149595A3 (en) 1986-07-30
EP0149595A2 (fr) 1985-07-24

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