Device and a method for transporting blanks made from an initially plastic, especially ceramic, material to and from a dryer and a kiln

A device and method for transporting blanks is provided. The blanks are made from an initially plastic, subsequently dried and finally fired material. A transport tray transports the blanks through both a dryer and a kiln. The blanks can be stacked on a drying trolley or a firing trolley. A first transfer device transfers the blanks onto the drying trolley when the blanks are stacked on the transport tray and are plastic. The drying trolley transports the blanks and the transport tray in the dryer for drying the blanks. A second transfer device transfers the blanks and the transport tray onto the firing trolley after the blanks have been dried. The firing trolley transports the blanks and the transport tray in the kiln for firing the blanks.

BACKGROUND

The invention relates to a device and a method for transporting blanks made from an initially plastic, especially ceramic, material to and from a dryer and a kiln.

In the manufacture of blanks made from a plastic, especially ceramic, material, in particular, with blanks used in the building industry, for the manufacture of buildings, for example, for bricks or roof tiles, the blanks are transported forward in the extrusion-moist condition, having been formed through extruders or other presses, and deposited on dryer trolleys of a dryer and/or on firing trolleys of the kiln, in order to be dried and then fired, dependent upon the consistency of the material, especially the moisture, or to be fired directly. In the first case named above, a transfer of the blanks from the dryer trolley to the kiln trolley is required in every case. In the second case named above, it is necessary to unload the kiln trolleys by means of an appropriate loading device, for example, with a gripping or suction system. Accordingly, in order either first to dry and then to fire the blanks, or to fire them directly, the prior art is relatively transport- and time-intensive.

SUMMARY

The invention is based upon the object of developing further an existing device or an existing method, so that the cost for transporting the blanks is or will be reduced.

Transport trays made from a heat-resistant material for the blanks are associated with the device according to the invention, wherein the supply device for supplying the blanks to the dryer provides a blank-loading device for loading each transport tray with blanks, and the removal and supply device for removing the dried blanks provides a transfer device for gripping and transferring the respective transport tray loaded with the blanks to the kiln. As a result, it is possible to transfer the fired blanks, in each case with the transport tray carrying them, from the drying trolley to the kiln trolley, wherein the blanks themselves need not be gripped and stressed. The transport tray with the blanks can be transferred in a simple manner, because the transfer device engages with the transport tray and transfers it to the kiln trolley. According to the invention, the transport of the blanks can be reduced and facilitated, both in the previously described transfer and also in the further conveyance of the blanks at the output of the kiln, because, at the kiln output, the blanks can also be transported further with the respectively associated transport tray and unloaded from the transport tray at an appropriate station.

The supply of the extrusion-moist blanks by setting them down with the transport tray at the set-down station at the input of the dryer is also simplified and improved.

The advantages described above also apply to the method according to an aspect of the invention, wherein the blanks are loaded onto the associated transport tray, in each case by means of a blank-loading device, and, after drying, the transport tray is gripped by means of a transfer device and transferred to the kiln with the blanks disposed on it.

Since the transport trays according to the invention are made from a correspondingly heat-resistant material, they are suitable not only for the drying process but also for the firing process.

Transport trays with a plate-shaped carrying element at the top, which is preferably flat on its upper side, are suitable as transport trays. The carrying function of the transport tray is guaranteed because the transfer device provides carrying elements, preferably fork-shaped carrying arms, which engage under the transport tray, or engage in the latter. Lateral recesses in the transport tray, into which the fork-shaped carrying elements can be introduced, for example, two or three fork-shaped elements, in each case, with a horizontal distance from one another, can be used for this purpose.

The engagement of the fork-shaped carrying arms in the transport tray also achieves the advantage that the carrying arms can be arranged simply in such a manner that they do not project over the edges of the transport tray, and accordingly, several transport trays can be arranged side-by-side on a drying trolley and/or kiln trolley, so that the available space can be better exploited, and the performance of the dryer and/or of the kiln can be increased.

Further advantages of the invention can be achieved by providing a transfer device which can be moved to the removal station for the dryer and/or to the removal station for the kiln, so that one and the same transfer device can be used to grip and to transport the dried blanks and/or the fired blanks, in each case on the associated transport tray. Such an advantageous embodiment and simple design and short transport distances can then be realised, if a single transfer device can be displaced along a preferably straight movement axis, especially transversely to the longitudinal direction of the dryer and of the kiln, into stations, in which it is, on the one hand, moveable a loaded transport tray from its loading station or an intermediate station to the supply set-down station of the dryer and/or from a dryer removal station to the supply set-down station of the kiln and/or from the kiln removal station to an intermediate station or a blank removal station for the transport tray.

The arrangement and embodiment of the transfer device described above is then especially advantageously suitable in combination with a dryer and/or a kiln, which provides two longitudinal portions disposed in the manner of a turning loop, which are arranged side-by-side, so that their input and output are associated with on one and the same side.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the exemplary embodiments to be described, the same or similar parts have been shown with identical reference numbers.

The device shown with reference number1, is used to transport blanks2made from an initially plastic, especially ceramic, material towards a dryer3and a kiln4. The blanks2are preferably disposed, in the form of a batch2a, for example, a stack of blanks, on a transport tray5, of which the horizontal longitudinal and transverse dimensions can correspond to the longitudinal and transverse dimensions of the blanks2or batches2adisposed on it. The transport trays5are made from a heat-resistant material appropriate for the firing temperature and are preferably embodied identically to one another. The top carrying surface of the transport tray5is, in particular, rectangular, for example, square, and is preferably formed by the flat, upper side of a plate-shaped carrying element5a. This can be a plate-shaped carrying element which provides laterally open recesses6, for example, two or three in number, which are used to receive, for example, two or three carrying arms of a transport means still to be described, which can be, for example, a transport device corresponding to or similar to a forklift, with which an unloaded or loaded transport tray5can be displaced vertically and horizontally. The recesses6can be formed by feet5bprojecting at the bottom, which are arranged at a distance from one another and at a distance from the edge of the transport tray5.

In one simple embodiment, the dryer3and/or the kiln4can be a drying or firing chamber, to which the loaded transport tray5can be supplied by a supply device7for a drying process and, after drying, can be removed again by a removal and supply device8and supplied to the firing chamber. After firing, an appropriate removal device is provided for the removal of the loaded transport tray5.

To improve performance in the exemplary embodiment, a throughput or tunnel dryer3and a throughput or tunnel kiln4is provided, through which a corresponding plurality of dryer trolleys9or firing trolleys11can be conveyed on a transport pathway, for example, on tracks, in each case by a suitable, per se known drive device (not illustrated), and onto which or from which the loaded transport trays5can be placed or respectively removed at the input and output.

For functional reasons and reasons of thermal technology, it is advantageous to arrange a set-down station12,13and removal station14,15respectively in front of and behind the dryer3and the kiln4in the throughput direction for setting down and picking up in each case a loaded transport tray5. A pre-heater4aindicated by dotted lines, through which the firing trolleys11can be conveyed for preliminary heating, can be arranged between the kiln4and the associated set-down station13.

For purposes of rational operation, it is also advantageous to provide a drying trolley circulation16and a firing trolley circulation17, which are each formed, for example, by four circulating conveyor paths16a,16b,16c,16dand17a,17b,17c,17d, on which the dryer trolleys9and respectively firing trolleys11can be conveyed by an appropriate and per se previously known conveyor device.

The functioning of the device1is described below with reference to the following advantageous method steps.

The device is suitable for blanks2made from an initially plastic, especially ceramic, material, which is initially dried in the dryer3dependent upon moisture content for the purpose of preventing distortion or cracks, and then fired in the kiln4, as is the case, especially in the manufacture of building elements, such as bricks and roof tiles.

After forming (for example through an extruder or other presses) the blanks2are deposited by a gripping or suction system at a loading station21, in the extrusion-moist condition onto the respective transport tray5. This therefore forms a batching device19or stacking device for building up a stack2aof blanks on the transport tray5. By means of a first transfer device22a, which can be, for example, a conveyor device with projecting carrying arms20, which can be inserted into the recesses6, as is conventional with a forklift, the loaded transport tray5is conveyed to the set-down station12on an available drying trolley9, and this trolley unit is then conveyed through the dryer3. The transport tray5of the respectively emerging trolley unit with dried blanks2is then deposited by means of an identical or similar second transfer device22bat the set-down station13disposed in front of the kiln4on the kiln trolley11available there, and this trolley unit is conveyed through the optionally available pre-heater4aand the kiln4towards the removal station15. Transported by means of a third transfer device22cprovided there, for example, another device with carrying arms20capable of being inserted into the recesses6, towards an unloading station24, at which the blanks2are removed from the stack by means of a stack-removal device25indicated schematically, and the transport tray5is unloaded. For a further improvement of functioning, a return device26for returning the unloaded transport trays5to the loading station21is provided for the device1.

It is advantageous to provide a storage device27,28, respectively for the drying trolleys9and transport trays5, in the region of the drying-trolley return-device16and the return-device26for the transport trays5. As a result, it is possible to avoid throughput disturbances and to vary the rate of operation of the dryer3and the kiln4, without getting into the situation of not having a drying trolley available in the region of the set-down station12and/or transport trays5in the region of the loading station21. The respective storage device27,28allows the respective arrangement of the drying trolleys9and transport trays5as a store, from which a drying trolley9and/or a transport tray5can be taken respectively.

Moreover, it is advantageous to cool the drying trolleys9and/or the transport trays5on their respective return path through an appropriate cooling device29or respectively31, so that the loaded blanks do not suffer distortion or cracks as a result of excessively rapid heating. The respective cooling device29or31is particularly effective especially if it is arranged in the region of the storage device27,28, where several drying trolleys9or transport trays5can generally be cooled at the same time. The cooling devices29,31, can, for example, provide a fan33, which generates an air stream passing over the drying trolley/s9and/or the transport tray/s5.

The exemplary embodiment according toFIG. 2differs from the exemplary embodiment according toFIG. 1in that a common transfer device22ais provided, which can implement at least two of the transfer functions described above and, can preferably be displaced transversely to the input and/or output of the dryer3and/or output of the kiln4, preferably along a straight movement line34, in such a manner that it can be displaced for the transfer from the loading station21or a parallel, intermediate supply station and the supply set-down station12of the dryer and/or between the dryer removal station14and the supply set-down station13of the kiln4and/or between the kiln removal station15and the blank removal station23or an intermediate removal station24, and can implement the transfer movements described above in its respectively associated movement station along the movement line34.

The exemplary embodiment according toFIG. 2, in which a transfer device22acan be used for at least two transfer stations, is particularly suitable for a dryer3or kiln4which provides in each case two longitudinal tunnel or throughput portions3a,3b, and4a,4b, which are arranged in the manner of a turning loop, so that they are disposed side-by-side and have their input and output at one and the same side. The ends of the longitudinal portions3a,3bfacing away from the input and output3c,3dare connected to one another by a transfer platform3e, by means of which the dryer trolleys9can be transferred from the input3ato the output3bin the manner of a conveyor path turning loop.

The turning-loop embodiment of the kiln4differs from the embodiment previously described in that the input4cis in fact disposed approximately in a transverse line with the previously described inputs3aand3b, but the output4dof the kiln4is disposed opposite to the input4cat a longitudinal distance a, which is greater than the longitudinal dimension of the transport tray5, so that this can be displaced inwards and outwards between the input4cand the output4d. With this embodiment, the kiln4provides three longitudinal portions4a,4d,4f, which are connected transversely to one another by two transfer platforms4eat the ends facing away from one another, through which the kiln trolleys can be transferred.

Moreover, the embodiment according toFIG. 10can correspond to the embodiment of the device1according toFIG. 1orFIG. 2.

In the exemplary embodiment, an extruder41which, during functional operation, extrudes an extrusion-moist slab42onto a conveyor43, which extends parallel to the dryer3or the kiln4and therefore longitudinally, is arranged on the side of the device1facing away from the kiln4. A cutting device44, with which the slab can be cut transversely into longitudinal portions which are not recognisable in detail, is arranged in the middle region of the slab42.

The three transfer devices described above, or respectively a common transfer device22a, can be moved transversely to and fro along a movement path45extending transversely to the input and output3a,3b,4a,4band indicated schematically. Moreover, a return device26for the transport trays5is provided.

The transport trays5are each conveyed from a return conveyor portion26ato a longitudinal conveyor46arranged on the side facing away from the kiln4, which conveys the respective transport tray5to the right inFIG. 10towards the loading station21, at which the cut blanks2are arranged or stacked on the transport tray5by a batching device19not illustrated in greater detail. The unit comprising the transport tray5and the blanks2is conveyed by the longitudinal conveyor46into the transverse region of the movement path45, from where the transfer device22adisplaces this unit transversely inwards and deposits it at the supply set-down station12of the dryer3on the dryer trolley disposed there. After this, the transport of the dryer trolleys9disposed one after the other, with the transport trays5and blanks2disposed on them, is implemented through the dryer, along the direction of the arrows.

At the output3b, the transport tray5with the blanks2is displaced transversely to the supply set-down station13at the input4aof the kiln4and deposited on the associated kiln trolley11, after which, the conveying of the firing trolleys11and transport trays5, with the blanks2arranged one behind the other, is then also implemented through the kiln4in a per se known manner. The horizontal size of the transport trays5can correspond to the horizontal size of the preferably mutually identical firing trolleys11.

However, the horizontal size, for example, the transverse width b of the transport trays5can also be equal to or smaller than an associated half horizontal dimension of the associated firing trolley11, so that two or more transport trays5fit onto each firing trolley11. For example, a plurality of transport trays5can be arranged respectively in two rows extending along the associated longitudinal portion4bof the kiln4.

In the cases described above, the associated transfer device22aoperates in such a manner that it alternately conveys a loaded transport tray5from the kiln removal station15to a conveyor47, offset, for example, towards the inside, and extending longitudinally, which supplies the blanks2to an unloading device48, indicated schematically, which removes the blanks longitudinally on a longitudinal conveyor49in the direction of the arrow51and, in each case, the transport tray5moves, transversely to the return portion26a, to the longitudinal conveyor46and towards the loading station21, while the blanks2can be transported to a packaging region.

With this exemplary embodiment, a storage device27for the dryer trolley9and a storage device28for the transport trays5is also provided in order to guarantee a disturbance-free operation of the device1. The storage device27can be arranged, for example, adjacent to the supply set-down station12of the dryer, for example, adjacent on the left. The storage device28for the transport trays5can be arranged, for example, disposed opposite to the output of the dryer portion3b, wherein appropriate conveyors are provided to convey the dryer trolleys9and the transport trays5optionally into and out of the associated storage device27,28. In the exemplary embodiment, the transfer device/s22ais/are illustrated by trapeze-shaped arrow portions.

FIGS. 3 and 4show a transfer device22a,22b,22c, which can be embodied in an identical manner and can be formed by a common transfer device22a, as has already been described.

The transport trays5can be embodied in one part or several parts, for example, comprising a plate-shaped carrying element5a, on the underside of which the feet5bare arranged in a rigid manner. In one simple embodiment, the feet5bcan also be separate components which form fixed or loose parts of the transport tray5. The cross-section of the feet5bcan be rectangular or tapering upwards, as is also shown inFIGS. 5 to 8.

FIG. 9shows a batch19or stack with blanks on transport trays5, which are positioned close to one another in a space-saving manner, so that the available space can be readily exploited.

One further substantial advantage of the device1according to the invention is that the transport trays5can be loaded or unloaded outside the kiln4or the associated supply set-down station12or dryer removal station14. As a result, the at least one transfer device and/or a stack-removal device can be arranged in an operationally favourable and space-saving manner.

FIG. 11shows a further modified embodiment of a device for transporting blanks to and from a dryer and a kiln according to the present invention. In this context, identical and similar elements and devices are provided with identical and similar reference numbers, as in the embodiments described above and the previously presented drawings. The presentation inFIG. 11corresponds to the presentation of the alternative embodiment fromFIG. 10. All of the deliberations and explanations provided above also apply for the embodiment ofFIG. 11, unless they are replaced by the following explanations.

With the embodiment illustrated inFIG. 11, as with the embodiments explained above, an implementation with two separate circulations for the dryer trolleys and the kiln trolleys is also proposed. Accordingly, it is possible to reduce the number of comparatively expensive kiln trolleys in the plant as a whole. In a similar manner to the case of the previous embodiments, with the embodiment fromFIG. 11, an extrusion-moist slab is also produced by an extruder41from a blank-extrusion material, subdivided by an appropriate cutting device into moist blanks and supplied to a transfer device22aby means of a conveyor43. The transfer device22ashown inFIG. 11engages over the first two tracks and supplies the fresh blanks at the same time to dryer trolleys9, which are disposed on the first two tracks. In this context, the fresh blanks in the sense of the present invention are not placed directly onto the dryer trolleys9, but onto transport trays, which have already been explained in detail above. In one minor modification of the previously explained embodiments, the transport trays are already arranged on the trolleys9at the time of placing the fresh blanks by the transfer device22a. The dryer trolleys9, with the transport trays and the fresh blanks disposed on them, are transported away by the transfer device22aon two tracks, that is, on the first two tracks illustrated (from above) inFIG. 11towards the right, and transferred to a transfer platform3e, which transfers the trolleys from the first and second track to the third track, on which the dryer trolleys9are transported in the direction towards the dryer3, to the left in the view fromFIG. 11. The two regions of the first tracks between the transfer device22aand transfer platform3eand the region between the transfer platform3eand the dryer3on the third track is marked as the region3a, which serves, so to speak, as a waiting region or supply region for the dryer3. For example, there are application situations, in which the extruder41and the cutting device only operate on working days and are supervised by personnel during these working days, while the fresh blanks on the dryer trolleys9are passed through the dryer3for automatic drying during the weekend. In this context, it is important that, at the beginning of the weekend, sufficient fresh blanks, which can be dried over the weekend in the dryer3, are already disposed on the dryer trolleys9. For this purpose, the region3ais used. The transfer platform3ewas also already presented, for example, inFIG. 10, and can move the trolleys from one track to the other in an automated manner. As an alternative, instead of a transfer platform, any other embodiment can be provided, which causes the trolleys to travel or to be moved from one track to the next track.

After the drying of the fresh blanks in the dryer3, the dried blanks are transferred, together with the transport trays, by a transfer device22bwith the embodiment already described in detail above, to firing trolleys11, which are disposed on the fourth track. The dried blanks, disposed together with the transport trays on the firing trolleys or kiln trolleys11, are then driven or conveyed through the kiln4. The transfer platform3ethen transfers the firing trolleys11with the fired blanks from the fourth track to the fifth track, where they are supplied to the transfer device22b. The transfer device22btransfers the transport trays with the fired blanks to drier trolleys9which are disposed on the first two tracks. The fired blanks are then supplied with the dryer trolleys, towards the right in the illustrated view, towards a further transfer device22c, which is disposed in the direction of movement in front of the transfer device22aalready explained above. The transfer device22cremoves the fired blanks from the transport trays disposed on the dryer trolleys9and supplies them to an unloading plant50, in which the fired blanks are further processed in a corresponding manner, for example, by packing and so on. The dryer trolleys9with the transport trays drive on from the transfer device22ctowards the transfer device22a, where they are loaded with fresh blanks.

The transfer platform4e, which, on the one hand, transfers dryer trolleys9after unloading by the transfer device22bback from the third track onto the first and second track, and on the other hand, transfers unloaded firing trolleys11from the fifth track to the fourth track, where they are again supplied to the transfer device22b, is clearly evident at the left-hand side ofFIG. 11. The transfer device22balways transfers the dried or respectively fired blanks together with the transport trays in the manner described above in greater detail.

As a result of the two separate circulations for dryer trolleys9and firing trolleys11, it is possible to reduce the number of firing trolleys. Firing trolleys11are more expensive than dryer trolleys9, so that a cost reduction can be achieved in this manner. With the embodiment shown inFIG. 11, it is possible to produce fresh blanks on working days, which are dried at the weekend in a semi-automatic or fully automatic manner in the dryer3and fired in the burner4. Since a sufficient number of fresh blanks must already be provided before the beginning of the weekend, (waiting region3a), the comparatively less expensive dryer trolleys9, of which an sufficient number must be available, can be used for this purpose. The more expensive firing trolleys11must only be available in the required number for filling the kiln4plus shunting operations on the fourth and fifth track. The transfer device22band dryer3and kiln4can run in a fully automated manner on seven days, while the production and provision of fresh blanks in the extruder41and so on, and the unloading and further processing of the fired banks can be implemented with personnel supervision only on working days.