Pouring device and method for preheating a melt transport device of a pouring device

Description

[0001] The invention relates to a casting device comprising a melt transport device and a preheating station for preheating a melt transport device, as well as a method for preheating the melt transport device by means of the preheating station.

[0002] In AT 523 252 A1, a melt transport device is designed with at least one melt container, in which a melt receiving chamber and a spout in the form of a lance located at the bottom of the melt container are formed, wherein the spout has a spout opening which is flow-connected to the melt receiving chamber.

[0003] In a casting process using the melt transport device known from AT 523 252 A1, it can happen that only an inadequate casting result is achieved.

[0004] Other melt transport devices are known from US 2012 / 146267 A1, CA 1 137 302 A, CN 113 547 110 A, US 4 359 209 A and CN 108 655 384 A. The object of the present invention was to provide an auxiliary device for the casting apparatus and a casting process by means of which an improved casting result can be achieved.

[0005] This problem is solved by a device and a method according to the claims.

[0006] The scope of the present invention is defined by independent claims 1 and 9, and further embodiments of the invention are set out in dependent claims 2-8 and 10-13.

[0007] The casting device according to the invention offers the advantage that, by means of the preheating station, the melt receiving chamber of the melt transport device can be brought to a sufficiently high temperature so that, upon commissioning or initial filling of the melt transport device, the melt encounters already pre-tempered surfaces. This largely prevents oxide formation during the melt reception. Oxide formation can be prevented by reducing the local cooling of the melt. Particularly with aluminum melts, this can improve the melt quality, as aluminum melts are especially prone to forming an oxide layer upon local cooling.The preheating station according to the invention offers the advantage that it allows the melt receiving chamber of the melt transport device to be heated to a sufficiently high temperature so that, upon commissioning or initial filling of the melt transport device, the melt encounters already pre-tempered surfaces. This largely prevents oxide formation during the melt's intake. Oxide formation can be prevented by reducing the local cooling of the melt. Particularly with aluminum melts, this can improve melt quality, as aluminum melts are especially prone to forming an oxide layer upon local cooling. Furthermore, this measure prevents local solidification of the melt on a cold surface.

[0008] Furthermore, it can be advantageous to incorporate a computing unit, whereby the air heater and the blower are controlled by the computing unit, and wherein a first temperature sensor is arranged in the flow channel and coupled to the computing unit, the computing unit being configured to control the air heater and the blower based on the information from the first temperature sensor. This allows the air volume flow and / or the temperature of the air volume to be precisely set or regulated. Thus, the heating time of the melt transport device can be predicted or precisely controlled.

[0009] Furthermore, the computing unit can be designed to connect to a second temperature sensor, with the second temperature sensor being located in the melt transport device. This offers the advantage that not only the output temperature of the preheating station can be measured, but also the actual temperature within the melt transport device. This allows the desired or target temperature in the melt transport device to be set with increased accuracy. In one embodiment, the second temperature sensor can be connected to the computing unit via a data line. In another embodiment, the second temperature sensor can be connected to the computing unit wirelessly.

[0010] Furthermore, the blower can be positioned upstream of the air heater when viewed in the direction of airflow. This has the advantage that the air flowing through the blower is not yet heated, which can increase the blower's service life.

[0011] In particular, the air heater can be positioned as close as possible to the transition to the melt transport device. This measure minimizes heat losses and thus maximizes energy efficiency.

[0012] Another advantageous design is one that incorporates a return channel, allowing at least portions of the exhaust air stream from the melt transport device to be returned to the flow channel. This offers the benefit of improved energy efficiency.

[0013] According to further training, it is possible for the return channel to open into the flow channel downstream of the blower, with the return channel opening into the flow channel in such a way that, utilizing the Venturi effect, the exhaust airflow is drawn into the flow channel. This has the advantage that the air flowing through the blower is not heated, which can increase the blower's service life.

[0014] Furthermore, it can be advantageous to incorporate a heat exchanger in the flow channel, coupled to an exhaust air duct for conveying an exhaust air stream from the melt transport device. This offers the advantage of improved energy efficiency, as the thermal energy of the exhaust air flowing from the melt transport device can be utilized.

[0015] Furthermore, the melt transport device is designed to include a melt container with a melt receiving chamber and a spout in the form of a lance located at the bottom of the melt container. The spout has a pouring opening that is fluidly connected to the melt receiving chamber, and the coupling of the preheating station is designed such that, when the preheating station and the melt transport device are coupled, the melt receiving chamber is fluidly connected to the flow channel. Particularly with a melt transport device designed in this way, the preheating station can achieve improved heating of the melt transport device. Thus, an improved casting result can be achieved with such a melt transport device. In particular, the quality of the casting result can be improved when casting molten aluminum.

[0016] Furthermore, the coupling of the preheating station is designed such that, when the preheating station and the melt transport device are coupled, the heated air volume is introduced into the melt receiving chamber via the lower lance. This has the advantage that not only the melt receiving chamber but also the lower lance can be heated to a predetermined target temperature.

[0017] In particular, the melt transport device may be equipped with a vacuum pump, which, during operation, can create a vacuum in the melt receiving chamber to allow the melt to be drawn into or selectively discharged. Especially with such a melt transport device, the lance and the melt receiving chamber can be circulated through the heated air volume to ensure uniform heating of the melt receiving chamber.

[0018] As an alternative to a vacuum pump, a free outlet duct for the heated air can be provided in the form of a chimney. Furthermore, a shut-off device can be installed in the chimney.

[0019] In one particular embodiment, the second temperature sensor can be located in the melt receiving chamber of the melt transport device. This offers the advantage that not only the output temperature of the preheating station but also the actual temperature within the melt transport device can be measured. This allows for more precise setting of the desired temperature within the melt transport device. Specifically, the second temperature sensor can be positioned above a maximum fill level within the melt receiving chamber. This largely prevents contamination of the second temperature sensor by melt, thereby extending its service life. Furthermore, the second temperature sensor can be protected from below by a splash guard.

[0020] Furthermore, according to independent claim 9, a method for preheating a melt transport device by means of a preheating station is provided.

[0021] The method according to the invention offers the advantage that the melt receiving chamber of the melt transport device can be heated to a sufficiently high temperature so that, upon commissioning or initial filling of the melt transport device, the melt encounters already pre-tempered surfaces. This largely prevents oxide formation during the melt's intake. Oxide formation can be prevented by reducing the local cooling of the melt. Particularly with aluminum melts, this can improve melt quality, as aluminum melts are especially prone to forming an oxide layer upon local cooling.

[0022] In particular, it can be advantageous if the air volume is heated to a temperature between 700°C and 1100°C, especially between 800°C and 1000°C, and preferably between 850°C and 950°C. Surprisingly, it has been found that, especially with an air volume heated to this temperature, energy-efficient heating of the melt transport device to the desired target temperature can be achieved. The specified air volume temperature has proven particularly advantageous for a desired target temperature between 300°C and 390°C.

[0023] Furthermore, it can be provided that the air volume is conveyed into the melt transport device until a temperature between 200°C and 450°C, in particular between 250°C and 420°C, preferably between 300°C and 390°C, is reached in a melt receiving chamber of the melt transport device, and that in a subsequent process step the melt transport device is used for casting a workpiece. Specifically, a temperature between 340°C and 360°C in the melt receiving chamber can be targeted. Particularly when casting molten aluminum, a melt transport device pre-tempered to this temperature offers the advantage that oxide formation during the intake of molten metal into the melt receiving chamber can be largely prevented.

[0024] Furthermore, it can be provided that a first melt transport device is used to cast a workpiece, while a second melt transport device is heated by the preheating station, and that in a subsequent process step, the first melt transport device is heated by the preheating station while it is used to cast a workpiece. This has the advantage that the melt transport device not yet in use can be preheated to the appropriate temperature so that it is ready for use at any time should a change of melt transport device be necessary for process reasons.

[0025] Furthermore, it may be provided that the preheating station has a first melt transport device mounting position and a second melt transport device mounting position, so that two melt transport devices can be heated simultaneously at the preheating station.

[0026] Another advantageous configuration is one in which, simultaneously with the blower conveying air volume into the melt transport device, a vacuum pump extracts air volume from the melt receiving chamber of the melt transport device. This ensures that the melt receiving chamber is heated thoroughly and uniformly.

[0027] For the purposes of this document, a lance is defined as a spout with a cross-section that is narrower than that of the melting vessel. In particular, the lance may be designed to be tubular, at least in part.

[0028] To better understand the invention, it is explained in more detail with reference to the following figures.

[0029] They each show, in a highly simplified, schematic representation: Fig. 1 a first embodiment of a melt transport device; Fig. 2 a first embodiment of a preheating station for preheating the melt transport device; Fig. 3 a schematic representation of a first embodiment of a casting device comprising the preheating station with a melt transport device mounted thereon; Fig. 4 a schematic representation of a second embodiment of a casting device comprising the preheating station with a melt transport device mounted thereon; Fig. 5 a schematic representation of a third embodiment of a casting device comprising the preheating station with a melt transport device mounted thereon; Fig. 6 a perspective view of an embodiment of a preheating station with two couplings for simultaneously mounting two melt transport devices.

[0030] It should be noted at the outset that in the differently described embodiments, identical parts are provided with the same reference numerals or component designations, and the disclosures contained in the entire description can be applied analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the figure directly described and illustrated, and these positional designations must be applied analogously to the new position if the position changes.

[0031] Fig. 1 shows a first embodiment of a melt transport device 1, which serves to transport melt 2.

[0032] This document describes the melt transport device 1 only to the extent that the described features are necessary for describing the preheating station 12. For a detailed description of the melt transport device 1 and for possible configurations of the melt transport device 1, reference is made to AT 523 252 A1, the contents of which are hereby incorporated into this application.

[0033] The melt transport device 1 has a melt container 3 in which a melt receiving chamber 4 is formed, which serves to receive the melt 2.

[0034] Furthermore, the melt transport device 1 can include a spout 5 which is coupled to the melt container 3. The spout 5 can be designed as an integral part of the melt container 3. Alternatively, the spout 5 can be designed as a separate component coupled to the melt container 3. The spout 5 can have a pouring opening 6 through which the melt 2 received in the melt container 3 can flow from the melt transport device 1 into a mold or a filling chamber of an injection molding machine.

[0035] As from Fig. 1 It can also be seen that the spout 5 is designed in the form of a lance 7.

[0036] Furthermore, a gas valve 8 can be provided, which is fluidically connected to the melt receiving chamber 4 and which is designed to regulate the gas input into the otherwise gas-tight melt receiving chamber 4. The gas valve 8 is arranged above a maximum fill level 9, so that no melt 2 can flow into the gas valve 8. The maximum fill level is selected such that when the melting vessel 3 is filled with melt 2 up to the maximum fill level 9, a gas-filled space remains in the melt receiving chamber 4, in which a pressure can be set by means of the gas valve 8.

[0037] As from Fig. 1As further evident, the melt transport device 1 may be provided with a siphon 10. In particular, the siphon 10 may be arranged on the underside of the lance 7. Alternatively, the siphon 10 may be integrated directly into the lance 7. A siphon 10 integrated into the lance 7 can operate according to the same principle as described here.

[0038] In Fig. 1 The melting vessel 3 is shown partially filled with melt 2.

[0039] As from Fig. 1 As further shown, the melt transport device 1 may be provided with or coupled to a vacuum pump 11. The vacuum pump 11 can draw a volume of air from the melt receiving chamber 4. This allows a negative pressure to be generated in the melt receiving chamber 4 during operation of the melt transport device 1.

[0040] Fig. 2shows a first embodiment of a preheating station 12 for preheating the melt transport device 1.

[0041] The preheating station 12 comprises a base assembly 13, which can serve to accommodate the individual components of the preheating station 12. In other words, the base assembly 13 can also be referred to as a frame or support structure. In particular, it may be provided that the base assembly 13 is formed by an assembly of several steel profiles or steel components.

[0042] Furthermore, a flow channel 14 may be provided for transporting a volume of air. The flow channel 14 may be attached to or held on the base assembly 13.

[0043] Furthermore, the flow channel 14 may be formed by a steel pipe. In particular, the flow channel 14 may be encased by insulation 15. The insulation 15 may, for example, be in the form of a ceramic fiber mat.

[0044] Furthermore, a coupling 16 may be provided, which serves to connect the melt transport device 1 to the base assembly 13. In particular, the coupling 16 may serve to connect the melt transport device 1 to the flow channel 14. Thus, a flow connection between the flow channel 14 and the melt transport device 1 can be established by means of the coupling 16. In particular, it may be provided that a flow connection can be established between the flow channel 14 and the melt receiving chamber 4 of the melt transport device 1.

[0045] As from Fig. 2As can be seen, the coupling 16 may comprise a first coupling part 17 and a second coupling part 18. The first coupling part 17 and the second coupling part 18 may be arranged at a distance from each other.

[0046] In particular, the first coupling part 17 may serve to support the load or stabilize the melt transport device 1. Furthermore, the second coupling part 18 may serve to create a tight connection between the melt transport device 1 and the flow channel 14 of the preheating station 12.

[0047] As from Fig. 2As can be seen, the second coupling part 18 can be designed in the form of a flange, which is arranged on an end face of the flow channel 14. The second coupling part 18 can include a seal 19, which serves to bear against the melt transport device 1 and thus to create a flow-tight connection between the flow channel 14 and the melt transport device 1. In particular, the seal 19 can be designed in the form of a ceramic sealing cord.

[0048] In a preferred embodiment, the seal 19 can be designed to rest against the base of the melt transport device 1. Specifically, the seal 19 can rest against the base of the melt transport device 1, surrounding the lance 7.

[0049] Furthermore, an air heater 20 may be arranged in the area of ​​the flow channel 14. A blower 21 may also be provided, which serves to convey the air volume in the flow channel 14. The blower 21 can convey the air volume in the flow channel in a flow direction 22. Fig. 3 Figure 23 shows a highly simplified, schematic representation of a casting device, where the same reference numerals or component designations are used for identical parts as in the preceding figures. Figure 1 and 2 to be used. To avoid unnecessary repetition, reference is made to the detailed description in the preceding sections. Figure 1 and 2 pointed out or referenced.

[0050] The casting device 23 comprises the melt transport device 1 and the preheating station 12. Furthermore, the casting device 23 may include a computing unit 24, which is configured to control a process for preheating the melt transport device 1 or for controlling a process for casting a workpiece. As shown in Fig. 3 As can be seen, a temperature sensor 25 may be arranged in the flow channel 14, which is designed to detect the temperature in the flow channel 14. Furthermore, a second temperature sensor 26 may be provided, which is arranged in the melt transport device 1. In particular, the second temperature sensor 26 may be arranged in the melt receiving chamber 4 of the melt transport device 1. Specifically, the second temperature sensor 26 may be arranged above the maximum fill level 9 in the melt receiving chamber 4. In the illustration according to Fig. 3The melt transport device 1 is coupled to the preheating station 12, thereby creating a flow connection between the flow channel 14 and the melt receiving chamber 4.

[0051] As from Fig. 3 It can be seen that an underside of the melt container 3 rests against the seal 19 of the second coupling part 18, thereby creating a tight connection between the melt receiving chamber 4 and the flow channel 14.

[0052] To heat the melt transport device 1, in particular the melt receiving chamber 4, a volume of air is drawn in by the blower 21 and blown into the flow channel 14. Within the flow channel 14, or before entering it, the air volume can be heated to a desired temperature by means of the air heater 20. The heated air volume can then be guided through the lance 7 into the melt receiving chamber 4. The pressure of the blower 21 then blows the heated air volume out of the melt receiving chamber 4. Additionally, the vacuum pump 11 can be used to pump the air volume out of the melt receiving chamber 4.

[0053] In the Fig. 4 Another embodiment of the casting device 23, which may be independent in itself, is shown, with the same reference numerals or component designations used for identical parts as in the preceding illustrations. Figures 1 to 3to be used. To avoid unnecessary repetition, reference is made to the detailed description in the preceding sections. Figures 1 to 3 pointed out or referenced.

[0054] As from Fig. 4 It can be seen that a return channel 27 is provided, by means of which at least parts of the exhaust air flow from the melt transport device 1 can be returned to the flow channel 14.

[0055] In another embodiment, not shown, it is also conceivable that the return channel 27 is designed such that the air conveyed from the melt receiving chamber 4 is completely returned to the flow channel 14. Thus, the air can be circulated. In this case, it may be necessary for the air conveyed via the return channel 27 to pass through the blower 21.

[0056] In the Fig. 5Another embodiment of the casting device 23, which may be independent in itself, is shown, with the same reference numerals or component designations used for identical parts as in the preceding illustrations. Figures 1 to 4 to be used. To avoid unnecessary repetition, reference is made to the detailed description in the preceding sections. Figures 1 to 4 pointed out or referenced.

[0057] Fig. 5 Figure 23 shows a further embodiment of the casting device. As shown Fig. 5 It can be seen that a heat exchanger 28 is arranged on the flow channel 14. The heat exchanger 28 can be coupled to an exhaust air channel 29 for conveying the exhaust air flow from the melt transport device 1.

[0058] The exemplary embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiment variants, but rather various combinations of the individual embodiment variants are also possible and this possibility of variation lies within the skill of the person skilled in this technical field due to the teaching on technical action by the present invention.

[0059] The scope of protection is defined by the claims. However, the description and drawings must be consulted for the interpretation of the claims. Individual features or combinations of features from the different embodiments shown and described can, in themselves, represent independent inventive solutions. The problem underlying these independent inventive solutions can be found in the description.

[0060] All references to value ranges in this description are to be understood as encompassing any and all sub-ranges thereof, e.g., the reference 1 to 10 is to be understood as including all sub-ranges, starting from the lower limit 1 and the upper limit 10, i.e., all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g., 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0061] Finally, for the sake of clarity, it should be noted that, for a better understanding of the structure, some elements have been shown not to scale and / or enlarged and / or reduced in size. Reference numeral list

[0062] 1 Melt transport device 2 Melt 3 Melt container 4 Melt receiving chamber 5 Pouring spout 6 Pouring opening 7 Lance 8 Gas valve 9 Maximum fill level 10 Siphon 11 Vacuum pump 12 Preheating station 13 Base assembly 14 Flow channel 15 Insulation 16 Coupling 17 First coupling part 18 Second coupling part 19 Gasket 20 Air heater 21 Blower 22 Flow direction 23 Pouring device 24 Computing unit 25 First temperature sensor 26 Second temperature sensor 27 Return channel 28 Heat exchanger 29 Exhaust duct

Claims

1. A casting device (23), comprising - a melt transport device (1); - a preheating station (12), wherein the preheating station (12) is configured for preheating a melt transport device (1), the preheating station (12) comprising: - a base assembly (13); - a flow channel (14) for transporting an air volume, wherein the flow channel (14) is arranged on the base assembly (13); - a coupling (16) for coupling the melt transport device (1) to the base assembly (13), wherein the coupling (16) is configured to establish a flow connection between the flow channel (14) and the melt transport device (1); - an air heater (20) for heating the air volume, wherein the air heater (20) is coupled to the flow channel (14); - a fan (21) for conveying the air volume in the flow channel (14) in a flow direction (22), wherein the melt transport device (1) has a melt container (3) with a melt receiving space (4) and a spout (5) in the form of a lance (7) located at the bottom of the melt container (3), wherein the spout (5) has a spout orifice (6), which is flow-connected to the melt receiving space (4), and wherein the coupling (16) of the preheating station (12) is configured such that, in the coupled state of the preheating station (12) and the melt transport device (1), the melt receiving space (4) is flow-connected to the flow channel (14), wherein the coupling (16) of the preheating station (12) is configured such that, in the coupled state of the preheating station (12) and the melt transport device (1), the heated air volume is introduced into the melt receiving space (4) via the lance located at the bottom.

2. The casting device (23) according to claim 1, characterized in that a computational unit (24) is formed, wherein the air heater (20) and the fan (21) are controlled by the computational unit (24) and wherein a first temperature sensor (25) is arranged in the flow channel (14) and is connected to the computational unit (24), wherein the computational unit (24) is configured to control the air heater (20) and the fan (21) based on the information of the first temperature sensor (25).

3. The casting device (23) according to claim 2, characterized in that the computational unit (24) is configured for coupling with a second temperature sensor (26), wherein the second temperature sensor (26) is arranged in the melt transport device (1).

4. The casting device (23) according to one of the preceding claims, characterized in that the fan (21) is arranged upstream of the air heater (20) as seen in the flow direction (22).

5. The casting device (23) according to one of the preceding claims, characterized in that a return channel (27) is formed, by means of which at least parts of an exhaust air flow from the melt transport device (1) can be returned into the flow channel (14).

6. The casting device (23) according to claim 5, characterized in that the return channel (27) opens into the flow channel (14) downstream of the fan (21) as viewed in the flow direction (22), wherein the return channel (27) opens into the flow channel (14) in such a way that the exhaust air flow is drawn into the flow channel (14) using the Venturi effect.

7. The casting device (23) according to one of the preceding claims, characterized in that a heat exchanger (28) is formed on the flow channel (14), wherein the heat exchanger (28) is coupled to an exhaust air channel (29) for conveying an exhaust air flow out of the melt transport device (1).

8. The casting device (23) according to claim 3, characterized in that the second temperature sensor (26) is accommodated in the melt receiving space (4) of the melt transport device (1).

9. A method for preheating a melt transport device (1) of a casting device (23) by means of a preheating station (12), comprising: - a base assembly (13); - a flow channel (14) for transporting an air volume, wherein the flow channel (14) is arranged on the base assembly (13); - a coupling (16) for coupling the melt transport device (1) to the base assembly (13), wherein the coupling (16) is configured to establish a flow connection between the flow channel (14) and the melt transport device (1); - an air heater (20) for heating the air volume, wherein the air heater (20) is coupled to the flow channel (14); - a fan (21) for conveying the air volume in the flow channel (14) in a flow direction (22), comprising the method steps of: - providing the preheating station (12); - providing the melt transport device (1); - coupling the melt transport device (1) to the preheating station (12), wherein the melt transport device (1) has a melt container (3) with a melt receiving space (4) and a spout (5) in the form of a lance (7) located at the bottom of the melt container (3), wherein the spout (5) has a spout orifice (6) which is flow-connected to the melt receiving space (4), and wherein the coupling (16) of the preheating station (12) is configured in such a way that, in the coupled state of the preheating station (12) and the melt transport device (1), the melt receiving space (4) is flow-connected to the flow channel (14), wherein the coupling (16) of the preheating station (12) is configured such that, in the coupled state of the preheating station (12) and the melt transport device (1), the heated air volume is introduced into the melt receiving space (4) via the lance located at the bottom; - heating the air volume by means of the air heater (20) and conveying the air volume into the melt transport device (1) by means of the fan (21) and thereby heating the melt transport device (1).

10. The method according to claim 9, characterized in that the air volume is heated to a temperature between 700°C and 1100°C, in particular between 800°C and 1000°C, preferably between 850°C and 950°C.

11. The method according to claim 9 or 10, characterized in that the air volume is conveyed into the melt transport device (1) until a temperature of between 200°C and 450°C, in particular between 250°C and 420°C, preferably between 300°C and 390°C, is reached in a melt receiving space (4) of the melt transport device (1), and that the melt transport device (1) is used to cast a workpiece in a subsequent method step.

12. The method according to one of claims 9 to 11, characterized in that a first melt transport device (1) is used for casting a workpiece while a second melt transport device (1) is heated by means of the preheating station (12) and that, in a subsequent method step, the first melt transport device (1) is heated by means of the preheating station (12) while the first melt transport device (1) is used for casting a workpiece.

13. The method according to one of claims 9 to 12, characterized in that, simultaneously to conveying the air volume into the melt transport device (1) by means of the fan (21), an air volume is extracted from the melt receiving space (4) of the melt transport device (1) by means of a vacuum pump (11).