EP3083102B1 - Regeneration device and its use - Google Patents

Description

Regeneration device according to the preamble of patent claim 1.

From the EP 0 343 272 A1 , of the EP 1 306 146 A2 , of the DE 21 13 657 A1 and the US 5 005 980 A Regeneration devices and a mixer device and methods for the preparation of foundry sand or of mixing concrete are known. In the EP 0 343 272 A1 The sand is poured batchwise into a container and mechanically processed by means of friction elements.

Against this background, the object of the invention is to provide a device which further develops the prior art.

The object is achieved by a regeneration device having the features of patent claim 1. Advantageous embodiments of the invention are the subject of dependent claims.

According to the subject invention, a mobile regeneration apparatus is provided for processing foundry old sands, the mobile regeneration apparatus comprising a cylindrical container having a lid and a bottom and the container having a first opening and / or a second opening and a plurality of rotationally driven ones friction elements formed in the container are provided, and the friction elements are disposed on a first shaft, and a first bearing formed on the first shaft is provided, and the first shaft has a second bearing spaced from the first bearing, and the friction elements between the first bearing and the second bearing are arranged and the container at the top has a first flange and at the bottom a second flange, wherein the first flange is frictionally connected to the lid and the second flange non-positively connected to the ground and the container on a em support frame arranged and movable by means of the support frame.

It is understood that the term foundry sand used in particular refers to that sand which forms the casting molds for a metal casting. In addition to the quartz grains, which can be assigned to a specific particle size fraction, the main components of the used sand are, in particular, the aggregates such as organic or inorganic binders and substances for increasing the thermal conductivity. Due to the addition of the aggregates, the used sand can not be used again in the foundry without treatment and must be disposed of. In addition to the significant environmental impact for the transport of large quantities of sand, additional significant disposal costs.

It should be noted that at least one opening for loading the container with waste sand and for removing the regenerated sand is provided on the container. The regenerated sand is also called regeneration. For a regernation of the sand, the shaft is preferably brought to a certain speed by an electric motor during or after the filling of the container with waste sand. As a result, the friction elements arranged on the shaft perform circular movements and transfer part of the mechanical energy into the sand to be regenerated. Depending on the number of revolutions of the shaft and duration of the sand is less or more heated and held in the container in suspension. Studies have shown that it is advantageous that the temperature of the sand in the regeneration is preferably in a range between 20 ° C and 350 ° C, and most preferably in a range between 50 ° C and 250 ° C. Furthermore, it is advantageous to determine the temperature of the sand and in another development to change the number of revolutions of the shaft as a function of the temperature and in particular to regulate. After a time interval, the sand is regenerated and can be removed. In order to facilitate handling it is to provide on the container a first opening for supplying the used sand and a second, spaced from the first opening second opening for removal of the regenerate. An advantage of the formation of two openings is that, without rotation of the container, the old sand can easily be supplied to the container and the regenerated material can be removed from the container. It has also been shown that at least Double storage of the shaft can increase the stability of the regeneration device considerably.

Another advantage of the device according to the invention is that the used sands can be almost completely regenerated. The degree of regeneration is above 60%, preferably above 85%, and most preferably above 95%. The degree of regeneration here is understood to mean the weight ratio of filled used sand to regenerated matter.

Studies have shown that batch operation, i. Supply of the total amount of regenerating sand at the beginning of the workup and removal of the regenerated amount of sand at the end of the workup is particularly advantageous and leads to the highest levels of regeneration. In particular, in the processing of so-called inorganic bound sands can be achieved in addition to degrees of regeneration above 95% after the workup of used sand each new sand quality. It turned out that even a repeated workup leads to no loss of quality and the used sand can be worked up as often as desired.

In a development, the cover is connected by means of a first screw connection to the first flange and the bottom to a second screw connection to the second flange. As a result, the parts can be easily disassembled and perform a revision of the system quickly and inexpensively. In particular, the friction elements arranged on the shaft and the shaft itself are subject to a closure and should be replaced from time to time. In another development, the first bearing is flanged to the top of the lid, preferably secured by means of screw non-positively on the lid.

According to a preferred embodiment, the first opening is designed as a filling device and / or as an exhaust air opening and the second opening as an outlet device and / or as a supply air opening. Investigations have shown that the quality of the regenerated material can be increased if a part of the fine dust formed during the treatment works over the exhaust air opening can be deployed. For this purpose, it is advantageous to provide a third opening which is at a distance from the first opening and which is designed as an exhaust air device, and / or a fourth exhaust air opening which is at a distance from the second opening and which is designed as a supply air device. In particular, if in addition to the exhaust opening and a supply air opening is formed, it is possible to remove a great deal of the resulting particulate matter from the sand.

In another embodiment, the bottom is formed as a Anströmkasten, wherein the Anströmkasten is delimited from the container by means of a nozzle plate. It is advantageous the fourth opening, d. H. In particular, it is advantageous to form the fourth opening on an underside of the floor, preferably in the middle or in the vicinity of the center of the floor. Furthermore, it is advantageous if the first opening and the second opening are formed directly on the container and have a nozzle-shaped design on the outside of the container.

According to a preferred refinement, one or more temperature sensors are arranged on the container in order to determine the temperature of the sand. In another development, hole-like formations for receiving the temperature sensors are provided in the container wall. It has been found that for a rapid and reliable determination of the sand temperature during the regeneration process, it is advantageous to guide the temperature sensors through the container wall and to attach them to the inside of the container. In another development, the sensors are fastened to the container wall at different vertical positions. Studies have shown that the quality of the treated sand and the degree of regeneration depend, inter alia, on the duration of the regeneration and in particular on the continuous temperature-time profile in the regeneration, ie in the treatment. Furthermore, it is advantageous to determine the number of revolutions of the shaft, preferably by means of a frequency converter, and to change it if necessary. As a result, the temperature of the sand in the container can both lower and increase. In particular, it is advantageous to use a programmable controller to control the number of revolutions of the shaft by controlling the electric motor based on the measured temperature of the sand and the time duration. It has been found that with a given filling quantity and a given old sand type, a predefined regernation program can be run through and the deviation determined by means of a setpoint-actual comparison, in particular the variables such as temperature, time and number of revolutions, and by means of a change in the number of revolutions reduce the rejection. Furthermore, the control unit can be connected to both with a shut-off device formed at the first opening and with a shut-off device formed at the second opening in order to enable automatic loading and unloading of the container. Automation can improve the quality of the regrind.

In another embodiment, the second bearing forms a frictional connection with the ground. Furthermore, it is advantageous if the base has a first shape and the first shape receives the second bearing, so that the second bearing is arranged outside the housing outside. This increases the ease of maintenance of the system. It has been found that due to the high mechanical forces which are exposed to the bearings, it is advantageous if the first bearing and the second bearing each have a grease nipple to simply grease the bearings can.

In order to further reduce the mechanical stress, it is advantageous according to another embodiment, to align the shaft parallel to the longitudinal axis of the cylinder. According to an alternative embodiment, a second shaft is provided with second friction strips. In particular for larger containers this ensures uniform mixing and preparation. Especially with large diameters, there is a large difference in speed between the tangential ends on the friction elements and the shaft-near regions on the friction elements. Among other things, this places high demands on the imbalance and the stability of the waves. By designating with two or more waves Regions in the container are not swept by the friction elements, it is particularly advantageous for increasing the efficiency in the work-up to provide at the areas on the inside of the container deflection bar. As a result, the sand is redirected to the center of the container and achieved a consistent quality.

In a preferred embodiment, the friction elements on a middle and two adjoining the central region outer regions. The middle region is preferably fully or almost completely inserted either in the first shaft or in the second shaft. Upon rotation of the first shaft and the second shaft abrasion by the sand takes place at the outer regions. To increase the service life of the friction element, a hard material layer is formed on the upper side and on the lower side in the outer regions. The upper side is in this case the side of the friction element, which in the direction of the first flange and the underside of the friction element is the side which points in the direction of the second flange. In an alternative embodiment, the outer regions of the friction element are completely or alternatively only that surface of the friction element, which has a component of the normal vector in the direction of rotation, coated with a hard material coating. In this case, it is preferable to join the hard material supports firmly and firmly with the friction element. Preferred materials for the hard material coatings are in particular hard metals such as so-called Widia coatings or nitrides. It goes without saying that the hardness of the coatings should always be greater than the hardness of the base material or the carrier material of the friction element. Studies have shown that the higher the hardness of the hard material support, the greater the service life of the friction elements. Furthermore, it is preferable to make the thickness of the hard material layer differently. Since the abrasion through the sand at the parts of the friction element which are further away from the shaft is greater as a result of the higher speed, it is preferable to increase the thickness of the hard material support at the remote parts.

Figur 1

eine Querschnitt auf eine nicht erfindungsgemässe erste Ausführungsform,

Figur 2

einen Querschnitt auf eine erfindungsgemäße zweite Ausführungsform,

Figur 3

einen Querschnitt auf eine erfindungsgemäße dritte Ausführungsform,

Figur 4

einen Querschnitt auf eine erste Weiterbildung des Reibelements,

Figur 5

einen Querschnitt auf eine zweite Weiterbildung des Reibelements,

Figur 6

verschiedene Ansichten auf eine mobile Ausführungsform der Regerationsvorrichtung.

In another embodiment, the hard material support is connected by means of a fastening means with the friction element and thereby the friction element is easily replaceable. Preferred fastening means are in particular screws and nuts. One advantage is that the friction elements have a particularly long service life, by being able to replace the hard material support in case of excessive wear or abrasion without the friction element has to be removed from the respective shaft. This reduces maintenance and shortens the maintenance time. Studies have shown that it is advantageous to fix the hard material support preferably at a uniform distance at three or more points.
In a development, the regeneration device is designed as a mobile regeneration device. All parts of the regeneration device are arranged on a support frame, which receives the entire weight. As a result, the regeneration device can be easily transported by means of a truck.
In another embodiment, the regeneration device has a tilting device. By means of the tilting device, the container can be tilted preferably up to 90 °. In particular, for transport on the truck, this is advantageous in order to reduce the height of the structure and thus to increase the mobility of the entire system.
The invention will be explained in more detail with reference to the drawings. Here similar parts are labeled with identical names. The illustrated embodiments are highly schematic, ie the distances and the lateral and the vertical extensions are not to scale and have, unless otherwise indicated, no derivable geometric relation to each other. In it show:

FIG. 1

a cross section of a non-inventive first embodiment,

FIG. 2

a cross section of a second embodiment according to the invention,

FIG. 3

a cross section of a third embodiment according to the invention,

FIG. 4

a cross-section of a first development of the friction element,

FIG. 5

a cross-section on a second development of the friction element,

FIG. 6

various views of a mobile embodiment of the Regerationsvorrichtung.

The picture of the FIG. 1 shows a schematic cross section of a not inventive regeneration device 5, designed for the treatment of foundry old sands, with a cylindrical container 10 with a cover 12 and a bottom 14, a plurality of rotationally driven formed in the container 10 disposed on a first shaft 30 friction elements 40. The longitudinal axis of the first shaft 30 is substantially aligned, preferably exactly parallel to the longitudinal axis of the container 10. On the first shaft 30, a drive in the form of an electric motor 20 and a first bearing 22 are arranged on the upper side of the shaft 30. On the underside of the shaft 30, which passes through the bottom 14 a spaced from the first bearing 22 second bearing 25 is arranged. The second bearing 25 forms with the bottom 14 a frictional connection. Both the first bearing 22 and the second bearing 25 each have a lubricating nipple 26. The friction elements 40 are disposed between the first bearing 22 and the second bearing 25 within the container 10. At the top, the container 10 has a first flange 42 and on the underside a second flange 44, wherein the first flange 42 frictionally with the cover 12 and the second flange 44 is frictionally connected to the bottom 14.

On the outside, the container 10 has two receptacles 50 for temperature sensors. The receptacles 50 each have recesses in the container wall, so that the temperature sensors measure the temperature within the container. Furthermore, the container 10 has a first opening 60, which is designed as a filling device and a second opening 70, which is formed as an outlet device and a third opening 80, which is designed as an exhaust device or as an exhaust port on. The first opening 60, the second opening 70 and the third opening 80 have on the outside of the container 10 a nozzle-shaped configuration. Automatic shut-off devices 110 are provided both at the first opening 60 and at the second opening 70.
The cover 12 is connected in each case by means of a first screw 82 with the first flange 42 and the bottom 14 with a second screw 84 with the second flange 14 each frictionally engaged and each easily. Furthermore, the first bearing 22 is flanged to the cover 12. The first bearing 22 is covered with a sleeve. The sleeve is connected at the bottom with a third screw 86 with the cover 12 and at the top by means of a fourth screw 88 with the electric motor. In order to monitor the rotational speed of the shaft 30, a frequency converter 100 is provided. At the exhaust port, a suction device can be attached to create a slight negative pressure in the container 10 and to suck the resulting dust. By the first opening 60 and the second opening 70 are not made airtight, flows through both openings 60 and 70 to air.

In the picture of the FIG. 2 a erfiindungsgemässe second embodiment of the regeneration device 5 is shown. Hereinafter, only the differences from the embodiment of FIG. 1 explained. For the sake of clarity, some details of the execution of the FIG. 1 not shown. The bottom 14 is formed as a Anströmkasten, wherein the Anströmkasten relative to the container 10 by means of a nozzle plate 115 delimited and the fourth opening 125 at the bottom of the bottom 14 as Zuluftöffnung or Supply air device is formed on the Anströmkasten. Furthermore, the Anströmkasten on a revision opening 127 for lubricating the second bearing 25. the nozzle bottom 115 has a plurality of holes through which the supplied air flows. As a result, the sand is also held in suspension during regeneration.

In the picture of the FIG. 3 a third embodiment of the regeneration device 5 according to the invention is shown. Hereinafter, only the differences from the embodiment of FIG. 1 or the FIG. 2 explained. For the sake of clarity, some details of the execution of the FIG. 1 or the FIG. 2 not shown. In this case, a second shaft 130 is provided with second friction strips 140. The bottom 14 now has a first shape, wherein the first shape receives the second bearing 25, so that the second bearing 25 are arranged outside the housing outside. Furthermore, a deflecting strip is provided on the inside of the container 10 is not shown.
In the picture of the FIG. 4 is a cross-section of a first embodiment of the friction element 40 shown. Only the differences from the embodiments of the preceding figures will be explained below. The friction element 40 has a central region 240 and two outer regions 250 adjoining the central region 240. The central region is preferably fully inserted in either the first shaft 30 or the second shaft 130. Upon rotation of the first shaft 30 and the second shaft 130, the mechanical energy is transferred from the two outer regions 250 to the sand. Accordingly, abrasion by the sand takes place at the outer regions 250. To increase the service life of the friction element 40, a hard material layer 260 is formed on the upper side and on the lower side in the outer regions 250. The upper side is in this case the side of the friction element 40, which in the direction of the first flange 42 and the underside of the friction element 40 is the side which points in the direction of the second flange 44. In an alternative embodiment, the outer regions 250 of the friction element 40 are complete or only the surface of the friction element formed in the direction of rotation 40 subjected to a hard coating or jacketed. In this case, it is preferable for the hard material supports 260 to be bonded to the friction element 40 in a material-locking and rigid manner, ie not releasably. Preferred materials for the hard coatings 260 are in particular hard metals such as so-called Widia coatings or nitrides. It goes without saying that the hardness of the coatings 260 should always be greater than the hardness of the base or support material of the friction element 40. Studies have shown that the higher the hardness of the hard material support 260, the greater the service life of the friction elements.

In the picture of the FIG. 5 is a cross-section of a first embodiment of the friction element 40 shown. Only the differences from the embodiments of the preceding figures will be explained below. The friction element 40 has, on the side which points in the direction of rotation of the first shaft 30 or in the direction of rotation of the second shaft 130, on the entire two outer regions 250 hard material supports 260. The hard material support 260 is connected to the friction element 40 by means of one or more fastening means 270. Preferred fastening means 270 are in particular screws and nuts. Due to the fastening means 270, the hard material support 260 is easily exchangeable. One advantage is that the friction elements 40 have a particularly long service life, in that the hard material support 260 can be replaced in the event of excessive wear or abrasion without the friction element 40 having to be removed from the respective shaft 30 or 130. This reduces maintenance and shortens the maintenance time. Investigations have shown that it is advantageous to fix the hard material support 260 to the outer region 250 at three points 280.

Preferably, the hard material support 260 according to a first variant I can be formed as a rectangular strip 300. Here, the outer wheels of the strip 300 protrude from the circle radius of the friction element.

According to a second variant II, the hard material support 260 is formed as a strip-shaped circular segment and forms, with the exception of the fastening means 270 form-fitting with the friction element 40 by the hard material layer 260 with the outer surface on the same radius as the friction element 40 is located.

According to a third variant III, the hard material support 260 is formed as a strip-shaped segment and forms at the junction with the friction element 40 a positive connection. On the outside of a flat surface 305 is formed.

In the picture of the FIG. 6 different views of a mobile embodiment of the regeneration device 5 are shown. Only the differences from the embodiments of the preceding figures will be explained below. In a first illustration I is a plan view is shown. The regeneration device 5 has a metering container 600 connected to the first opening 60. Further, a blower 610 is provided to introduce air into the container 10, preferably from the bottom of the container 10 by means of a nozzle bed, not shown, in the lower region. In the container 10 can thereby easily form a flow of air and to keep the sand during regeneration in limbo. The exhaust air or the dust escapes with the air flow preferably through the third opening 80. At the side facing away from the first representation I side, that in this case behind the container 10, a control and switching cabinet 620 is arranged. In the control and switching cabinet 620, all the electrical devices and sensors of the regeneration device 5 are arranged for controlling or reading. All parts of the regeneration device 5 are arranged on a support frame 630, which receives the entire weight. As a result, the regeneration device 5 can be implemented as a mobile regeneration device. In particular, the regeneration device 5 can be easily transported by means of a truck.

According to the second illustration II, the control and switching cabinet 620 is arranged at a distance from the container 10. This allows a transfer of vibration from the container to the control and switching cabinet Reduce 620. Furthermore, a tilting device 640 is formed. By means of the tilting device 640, the container 10 can be tilted preferably up to 90 °, most preferably between 5 ° and 90 °. In particular, for transport on the truck, this is advantageous in order to reduce the height of the structure and thus to increase the mobility of the entire system.

In the third illustration III, a top view from above of the regeneration device 5 is shown. The first opening 60 is arranged centrally in the dosing tank 600.

Claims (18)

1. Regeneration device (5) constructed for preparation of reclaimed foundry sands, comprising:

   - a cylinder-shaped container with a lid (12) and a base (14),

   - a first opening (60) and/or a second opening (70),

   - a plurality of friction elements constructed to be rotationally driven in the container, wherein the friction elements are arranged on a first shaft, and

   - a first bearing (22) constructed at the first shaft,

   characterised in that
   the first shaft has a second bearing (25) spaced from the first bearing (22) and the friction elements (40) are arranged between the first bearing (22) and the second bearing (25),
   the container (10) has a first flange (42) at the upper side and a second flange (44) at the lower side, wherein the first flange is non-positively connected with the lid and the second flange is non-positively connected with the base,
   the container (10) is arranged on a support frame (630) and is movable by means of the support frame, and
   the base is constructed as an inflow box, wherein the inflow box is delimited relative to the container by means of a nozzle base (115).
2. Regeneration device (5) according to claim 1, characterised in that the lid is connected with the first flange by means of a first screw connection (82) and the base is connected with the second flange by a second screw connection (84).
3. Regeneration device (5) according to claim 1 or 2, characterised in that the first opening is constructed as a filling device and/or as an air exhaust opening and the second opening is constructed as an outlet device and/or as an air feed opening.
4. Regeneration device (5) according to any one of claims 1 to 3, characterised in that a third opening (80) spaced from the first opening and constructed as an air exhaust device and/or a fourth opening (125) constructed as an air feed device is or are provided and the fourth opening is spaced from the second opening.
5. Regeneration device (5) according to claim 4, characterised in that the fourth opening is formed at the inflow box.
6. Regeneration device (5) according to claim 5, characterised in that the nozzle base (115) has a plurality of apertures, wherein the supplied air flows through the apertures in order to keep the sand in suspension during the regeneration.
7. Regeneration device (5) according to one of claims 4 and 5, characterised in that the fourth opening is formed at an underside of the base.
8. Regeneration device (5) according to any one of claims 1 to 7, characterised in that the first opening and the second opening are formed at the container and have a support-shaped construction at the outer side of the container (10).
9. Regeneration device (5) according to any one of the preceding claims, characterised in that a temperature sensor is arranged at the container (10).
10. Regeneration device (5) according to any one of the preceding claims, characterised in that the second bearing forms a non-positive connection with the base.
11. Regeneration device (5) according to any one of the preceding claims, characterised in that the base has a first shaped portion and the first shaped portion receives the second bearing so that the second bearing is arranged outside the housing outer side.
12. Regeneration device (5) according to any one of the preceding claims, characterised in that the first shaft (30) is oriented parallel to the longitudinal axis of the cylinder.
13. Regeneration device (5) according to any one of the preceding claims, characterised in that a second shaft (130) with second friction strips (140) is provided.
14. Regeneration device (5) according to claim 13, characterised in that a deflecting strip arranged at the inner side of the container (10) is provided.
15. Regeneration device (5) according to any one of the preceding claims, characterised in that the friction elements (40) have a coating (260) of mechanically resistant material.
16. Regeneration device (5) according to any one of the preceding claims, characterised in that at least one temperature sensor is arranged at the container and a programmable control device is provided in order to regulate the rotational speed of the shaft by control of the electric motor on the basis of the measured temperature of the sand and the time duration.
17. Regeneration device (5) according to any one of the preceding claims, characterised in that the container (10) comprises a tipping device in order to tip the container (10) relative to the support frame (630).
18. Use of the regeneration device (5) for regeneration of sand according to any one of the preceding claims, wherein the entire sand quantity is supplied at the start of the recycling and removed at the end of the recycling.

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