Device and method for charging a glass melting plant

Abstract

Device for feeding a glass melting plant with bulk material consisting of cullet (4) and raw material mixture (5), comprising a first storage container (10) for the shards (4) and a second storage container (20) separate from the first storage container (10) for the raw material mixture (5) and an output section (2), wherein the output section (2) has a distribution chamber (26, 26'), and at least two adjacent extraction devices (3) in the form of a conveying means, each comprising a screw conveyor, a vibrating trough or a vibrating tube, wherein the at least two adjacent extraction devices each convey the bulk material parallel to each other from the outlet section (2) to an inlet of the glass melting plant along a conveying direction (33), wherein the device has a metering device (22) connected to the second storage container (20), which forcibly conveys the raw material mixture (5) from the second storage container (20) into the distribution chamber (26, 26') of the outlet section (2), wherein the distribution chamber (26, 26') receives the raw material mixture (5) over a width (28) of the device transverse to the conveying direction (33), which overlaps at least the at least two extraction devices (3), and transports it in a transport direction separate from the shards (4) to the at least two extraction devices (3), wherein the shards (4) and the raw material mixture (5) are brought together in the transport direction in and / or behind an outlet of the distribution chamber (26, 26') and in and / or behind an outlet (11) of the first storage container (10) in the respective extraction device (3).

Description

[0001] The invention relates to a device and a method for feeding a glass melting plant with bulk material consisting of cullet and a mixture of raw materials.

[0002] In the production of glass products, the bulk material continuously fed into the glass melting plant consists of cullet and primary raw materials (raw material mixture). This bulk material is also referred to as melting material. The cullet can originate from rejected production runs and / or be so-called recycled cullet. The raw material mixture refers to the starting materials for glass production. These include, for example, quartz sand, soda ash, nitrate, sulfate, sodium sulfate, potash, feldspar, alumina, lime, and dolomite. These raw materials are fed into the glass melting plant in the desired composition as a raw material mixture.

[0003] Adding cullet to the melting process has a positive impact on the melting behavior and energy consumption of the glass melting plant. Adding cullet accelerates the entire melting process and reduces energy requirements. Using a raw material mixture alone, without cullet, to produce the glass melt results in significantly higher energy consumption. It has been shown that increasing the amount of cullet added by 10% by weight reduces energy consumption in container glass production by approximately 3%. However, it is essential that the ratio of raw material mixture to cullet is controlled and maintained within a narrow range. A fluctuating ratio would mean that the melting energy requirement would also fluctuate, which is undesirable in glass production.

[0004] The desired ratio of cullet to raw material mixture is typically set in an open system using metering screws or simple weighing. The device located upstream of the glass melting furnace is supplied with the cullet and raw material mixture for storage. The two components are layered on top of each other in a silo. During removal, the two components are thoroughly mixed.

[0005] Further energy savings can be achieved by supplying heat energy from the hot exhaust gases of the glass melting plant to the shards and the raw material mixture.

[0006] With a high proportion of cullet available, it is economically advantageous to transfer this usable heat only to the cullet stream. Since the material streams must be combined in a specific mass ratio before entering the glass melting plant, open weighing of the components is not practical in this case, as the preheated cullet would then release the heat again. Furthermore, significant dust generation is to be expected in the transfer and mixing area, and heat transfer from the cullet to the raw material mixture leads to clumping and adhesion of the raw material mixture in the storage container or conveying system.

[0007] Document US 5,123,942 A discloses a loading machine for charging a glass melting furnace. Raw material falls from a primary loading hopper through a valve into a secondary loading hopper. From there, it slides down onto a loading plate that moves back and forth. A sand seal prevents the raw material on the loading plate from moving backward as the plate moves back. This causes a load of raw material to fall onto a surface of molten glass in the glass melting furnace from a protrusion on the loading plate opposite the sand seal. A cullet hopper is provided between the loading hopper and an outlet of the loading machine. This cullet hopper deposits a layer of cullet material over a layer of raw material previously deposited on the loading plate. The height of the cullet layer is adjusted by a height-adjustable gate plate on the front of the cullet hopper.The feed hopper contains adjacent chambers formed by vertical, spaced-apart partitions. These chambers hold the raw material for placement on the insert plate. Each chamber has a height-adjustable cover plate, allowing the thickness of the raw material layer on the insert plate to be set.

[0008] A device for feeding a glass melting plant with bulk material consisting of cullet and raw material mixture, which achieves improved results with regard to dust formation in the transfer area, is known from German patent application DE 10 2014 010 914 A1. In the device described in this document, the raw material mixture is conveyed directly into a discharge hopper of a storage container for the cullet. The feeder for the raw material mixture in the storage container is equipped with a roof-shaped cover, so that the forced-feed raw material mixture falls directly into the cullet stream. The fed raw material mixture is carried along by the cullet stream.

[0009] To increase the conveying rate of the molten material to the glass melting plant, it would be desirable to use multiple discharge devices. However, it has been shown that when using two or more discharge devices in known feeding systems, a reliable and uniform distribution of the raw material mixture to the different discharge devices is not achieved. This alters the ratio of raw material mixture to cullet.

[0010] The object of the present invention is therefore to provide a device and a method for achieving a higher conveying rate of bulk material as molten material to an inlet of a glass melting plant. Furthermore, the addition should be as dust-tight as possible.

[0011] The above-mentioned problem is solved by a device for feeding a glass melting plant with bulk material consisting of shards and raw material mixtures, having the features of claim 1.

[0012] According to the invention, the device comprises a first storage container for the cullet and a second storage container for the raw material mixture, separate from the first storage container, as well as an outlet section, wherein the outlet section has a distribution chamber, and at least two adjacently arranged extraction devices, which each convey the bulk material parallel to each other from the outlet section to an inlet of the glass melting plant along a conveying direction, wherein the device has a metering device connected to the second storage container, which forcibly conveys the raw material mixture from the second storage container into the distribution chamber of the outlet section. wherein the distribution chamber receives the raw material mixture across a width of the device transverse to the conveying direction, which overlaps at least the two extraction devices, and transports it in a transport direction separate from the shards to the two extraction devices, wherein the shards and the raw material mixture are brought together in the transport direction in and / or behind an outlet of the distribution chamber as well as in and / or behind an outlet of the first storage container in the respective extraction device.

[0013] In the device according to the invention, the outlet section is the section of the device located directly in front of the at least two dispensing devices. The outlet section, which could also be referred to as the storage outlet section, comprises the distribution chamber in the area of ​​the raw material mixture and, in the area of ​​the cullet, the end of the first storage container facing the dispensing devices. At the end or outlet of the outlet section located in the direction of transport, the cullet or the raw material mixture is fed to the dispensing devices and combined there.

[0014] The present invention transports the raw material mixture, forcibly conveyed by the metering device, as well as the preferably preheated cullet, to the at least two discharge devices. This allows the at least two discharge devices to contribute to conveying the bulk material to the inlet of the glass melting plant. This results in a higher overall conveying capacity of molten material to the inlet of the glass melting plant.

[0015] In the context of the present invention, the inlet of a melting vessel / (glass) melting tank forms the inlet of the glass melting plant. The melting vessel is the vessel in which the cullet and the raw material mixture are melted. The molten glass is drawn off from the melting vessel at the end opposite the inlet for subsequent processing.

[0016] The total throughput is the weight of the bulk material or molten material conveyed by the at least two discharge devices per unit of time to the inlet of the glass melting plant. It can be expressed, for example, in the unit t / h (tons per hour). The proportion of the raw material mixture is always understood to be the weight percentage of the raw material mixture to the total weight of the bulk material per unit of time, unless explicitly specified otherwise.

[0017] According to the invention, distributing the raw material mixture to the at least two extraction devices results in a more uniform and improved distribution of the raw material mixture in the glass melt of the glass melting plant. The flows of the raw material mixture and the cullet are kept separate from each other until they are combined in and / or downstream of the outlet of the first storage container and in and / or downstream of the outlet of the distribution chamber. They are only combined in the respective extraction device. The sequence in which the cullet is fed from the first storage container and the raw material mixture from the distribution chamber to the respective extraction device, in the transport or conveying direction, can be any sequence, with varying advantages.Furthermore, the distribution chamber can be positioned at a distance D from the end of the first storage container facing the dispensing devices (the distance is measured between the opposing walls of the distribution chamber and the first storage container, respectively). This distance D can be, for example, between 100 mm and 2000 mm. Because the distribution chamber transports the raw material mixture, which is forcibly conveyed by the dosing device, to the at least two dispensing devices, it is not necessary to provide a separate dosing device for each of the dispensing devices. This significantly reduces the complexity and space requirements of the device and improves its efficiency, cost-effectiveness, and reliability.

[0018] Within the scope of the present invention, the transport direction is defined as the direction of movement of the raw material mixture from the second storage container, through the metering device, through the distribution chamber, and along the discharge device until it is discharged into the glass melting plant. The transport direction is generally not linear, but may, for example, include bends and / or kinks. In the area of ​​the discharge device, the transport direction runs parallel to the conveying direction of the respective discharge device.

[0019] According to the invention, the discharge devices each comprise a screw conveyor, a vibrating trough, or a vibrating tube. Both vibrating troughs, vibrating tubes, and screw conveyors are sufficiently robust and suitable for conveying the required quantity of bulk material. The discharge devices are arranged below the outlet of the distribution chamber or the outlet of the first storage container, so that the raw material mixture or the cullet falls into the respective discharge device due to gravity.

[0020] Preferably, the proportion of cullet in the molten material is more than 50% by weight, particularly preferably more than 65% by weight, and most preferably more than 80% by weight. The greater the proportion of cullet in the molten material conveyed to the inlet of the glass melting plant, the more energy-efficient the operation of the glass melting plant can be. Since the raw material mixture constitutes a smaller proportion of the molten material, only the conveying capacity of the metering device for supplying the at least two discharge devices with raw material mixture needs to be regulated. As it continues along the transport path, the raw material mixture, due to its small proportion in the bulk material, distributes itself well and is transported along with the bulk material towards the glass melting plant.

[0021] In an advantageous embodiment, the device is designed for a total conveying capacity of 2 t / h to 37.5 t / h (corresponding to approximately 50 t / day to 900 t / day) of molten material to the inlet of the glass melting plant, particularly preferably 4 t / h to 25 t / h (corresponding to approximately 100 t / day to 600 t / day), and most preferably 10 t / day to 18 t / day (corresponding to approximately 250 t / day to 450 t / day). With such a feed rate of molten material, glass melting plants can be operated particularly efficiently. This feed rate is especially suitable for a melting plant for packaging glass, which uses a larger proportion of recycled cullet compared to other glass manufacturing processes.

[0022] Preferably, the cullet is fed simultaneously and continuously from the first storage container to at least two discharge devices. This allows for particularly easy control of the at least two discharge devices. In particular, they can each be operated at the same conveying rate. Since the cullet constitutes a larger proportion of the melt, this procedure ensures a uniform supply of molten material to the glass melting plant.

[0023] In a further embodiment of the invention, heat from hot exhaust gases of the glass melting plant is supplied to the first storage container for the cullet via a heat exchanger arranged in the first storage container, thereby preheating the cullet. This results in significant energy savings. By combining the cullet and the raw material mixture in the discharge section of the device only after the distribution chamber or in the respective discharge device of the at least two discharge devices, premature heating of the raw material mixture by preheated cullet is avoided. Premature heating of the raw material mixture would cause the soda contained in the raw material mixture to release the water bound to it in a decomposition process at a low temperature.Then the raw material mixture would no longer be free-flowing and could back up. Furthermore, warmed raw material mixture could stick to the respective container or conveying device. This would significantly hinder or even prevent the dosing and, in particular, the distribution of the raw material mixture to the various dispensing devices, ultimately leading to an uneven distribution of the raw material mixture at the inlet of the glass melting plant and within the glass melt.

[0024] It has proven advantageous if the metering device, which forcibly conveys the raw material mixture into the distribution chamber of the output section, and / or the distribution chamber itself are sealed dust-tight to the outside. This prevents unwanted dust formation.

[0025] Preferably, the at least two discharge devices convey the molten material to different inlets of the glass melting plant. This significantly improves the distribution of the molten material within the glass melt. Better distribution of the molten material results in faster heating of the glass, thus enabling more economical operation of the glass melting plant.

[0026] In a further development of the invention, the two dispensing devices are arranged at the same height with respect to one direction of gravity. This facilitates the uniform transport of the raw material mixture through the distribution chamber into the at least two dispensing devices.

[0027] Preferably, the at least two discharge devices extend counter to the conveying direction along the outlet of the first storage container and the outlet of the distribution chamber. This allows the raw material mixture to be easily combined with the cullet in the conveying direction only after the outlet of the distribution chamber and after the outlet of the first storage container, and also facilitates the conveying of the bulk material from the outlet section of the device to the inlet of the glass melting plant. The cullet and the raw material mixture are particularly preferably combined in the area of ​​the outlet of the first storage container or in the area of ​​the outlet of the distribution chamber.

[0028] In a further, preferred embodiment of the invention, the outlet of the distribution chamber is arranged in front of the outlet of the first storage container with respect to the conveying direction.

[0029] In another embodiment, the distribution chamber can be separated from the outlet of the first storage container, preferably along a section of the first storage container in the outlet segment, by a partition, which is preferably made of a heat-resistant steel alloy. It is highly preferred that the partition is provided with a hard material as wear protection on a first side facing the first storage container. This increases the durability of the partition and reduces downtime of the device. Alternatively, the distribution chamber can be formed by a substantially box-shaped (cassette-shaped) container, which is also preferably made of a heat-resistant steel alloy. The box-shaped container is a cuboid hollow body that is closed to the environment except for the inlet and the at least two outlets for the raw material mixture (one outlet for each dispensing device).This ensures in a simple and effective way that the raw material mixture in the distribution chamber is transported separately from the shards in the direction of transport to the at least two extraction devices.

[0030] In a further development of the invention, a metering outlet of the metering device leads into the distribution chamber. The raw material mixture is forcibly conveyed into the distribution chamber by the metering device.

[0031] In one embodiment of the invention, a distribution device is arranged in and / or on the distribution chamber, which distributes the raw material mixture supplied from the metering device evenly across the entire width of the distribution chamber. This ensures that the raw material mixture is transported evenly towards the at least two dispensing devices. During transport, the raw material mixture can be accumulated and thus stored in the distribution chamber in front of one or more of the at least two dispensing devices.

[0032] The distribution device preferably includes a deflector that can be rotated about an axis of rotation into at least two different positions, with the metering outlet for adding the raw material mixture opening into the distribution chamber in the transport direction upstream of the axis of rotation. The metering outlet directs the raw material mixture towards the deflector. Most preferably, the axis of rotation runs essentially parallel to the conveying direction or transversely to the transport direction of the raw material mixture.

[0033] Preferably, the width of the deflector is at least 10 mm, and more preferably at least 5 mm, shorter than the depth of the distribution chamber. This ensures sufficient mechanical clearance for the deflector. In a further, particularly preferred embodiment of the invention, the deflector is designed as a plate-shaped element. In particular, the deflector can be designed as a flat iron bar or as a suitably profiled element at its respective ends, for example, with one angle (L-profile) or two angles (double-T-profile). This allows for simple and cost-effective manufacturing of the deflector.

[0034] A motor and gearbox for rotating the deflector are particularly preferred. The motor and gearbox allow the deflector to be pivoted or rotated into at least two different positions.

[0035] Alternatively, the deflector can be designed as a vibrating distributor, which moves back and forth in a direction perpendicular (transverse) to the transport direction and is located below the metering outlet. The deflector designed as a vibrating distributor also serves to distribute the raw material mixture supplied from the metering device evenly across the entire width of the distribution chamber.

[0036] In an advantageous embodiment of the invention, the distribution device comprises at least two of the deflectors described above, which are preferably arranged side by side in and / or on the distribution chamber (in a direction transverse to the transport direction of the raw material mixture). This allows the raw material mixture, forcibly conveyed from the metering device into the distribution chamber, to be easily distributed to more than two dispensing devices, in particular to more than three dispensing devices, by the interaction of the at least two deflectors.

[0037] It has proven advantageous if at least three adjacent discharge devices each convey the bulk material parallel to one another from the outlet section of the device to the inlet of the glass melting plant along the conveying direction, and if the distribution chamber receives the raw material mixture across the width of the device transversely to the conveying direction, which overlaps at least the three discharge devices, and transports it separately from the cullet to the three discharge devices. This allows for an even higher overall conveying capacity. Furthermore, the molten material is distributed even more effectively at the inlet of the glass melt. The three discharge devices are particularly preferably arranged in a row transversely to the conveying direction, and most preferably at equal intervals.It is also advantageous if the at least three dispensing devices are each arranged at the same height relative to one direction of gravity. This makes it particularly easy and efficient to distribute the raw material mixture among the at least three dispensing devices.

[0038] In a further embodiment of the invention, the device has three dispensing devices and a deflector in and / or on the distribution chamber, which can be rotated in at least three positions. In this way, the raw material mixture can be evenly distributed across the entire width of the distribution chamber with just one deflector and transported to the three dispensing devices.

[0039] According to a further embodiment of the invention, the device has four or five dispensing devices arranged side by side and three deflectors in the distribution chamber. The three deflectors ensure that the raw material mixture is evenly distributed in the distribution chamber, so that all four or five dispensing devices are supplied with the raw material mixture evenly. The three deflectors are arranged in and / or on the distribution chamber such that an upper deflector is positioned centrally above the two lower deflectors, which are arranged at the same height. The upper deflector is located below the dispensing outlet of the dispensing device in the direction of transport.

[0040] In a further development of the invention, the second storage container rests on at least one, and preferably at least three, pressure sensors (weight load cells). The pressure sensor(s) allow the amount of raw material dispensed from the second storage container per unit of time to be measured. This enables more precise monitoring and / or control of the device.

[0041] In a further embodiment of the invention, the device comprises a control unit. The total conveying capacity per unit of time, for example in tons per hour (t / h), can be entered into the control unit. Alternatively and / or additionally, it can be provided that a total production output per unit of time for a discharge point (production), in particular for the glass melting plant or for downstream glass processing, can be entered. The total production output is calculated, for example, from the weight of finished products (here, the molten glass discharged by the glass melting plant). In this case, the control unit calculates the required total conveying capacity of the bulk material to be supplied.

[0042] Preferably, the proportion of the raw material mixture to the melt is freely selectable and entered into the control unit, for example, as a percentage of the total throughput. It has proven advantageous to record the weight loss of the second storage container over a time interval, for example, every fifteen minutes, and compare it with the entered proportion of the raw material mixture by the control unit. If there is a deviation from the entered proportion, the dosing of the raw material mixture is preferably adjusted (controlled) by the dosing device in predetermined, fixed increments according to the specified value. These incremental adjustments are made at further time intervals until the recorded weight loss of the raw material mixture per unit of time corresponds to the entered proportion within a tolerance range that is calculated in the process control system.Setting the parameters at fixed time intervals and with specific step sizes ensures that the control system does not tend to overshoot. To start up the system, the delivery rate of the dosing device can be set to a lower limit (minimum dosing).

[0043] The above-mentioned problem is further solved by a method for feeding glass melting plants with bulk material consisting of shards and raw materials with the features of claim 7.

[0044] According to the inventive method, a first storage container receives the shards and a second storage container, separate from the first storage container, receives the raw material mixture. wherein the bulk material is conveyed by means of two adjacent extraction devices, each parallel to each other, from an outlet section of the device to an inlet of the glass melting plant along a conveying direction, wherein the raw material mixture is forcibly conveyed from the second storage container into a distribution chamber of the output section by means of a dosing device connected to or attached to the second storage container, wherein the raw material mixture is taken up by the distribution chamber over a width of the device transverse to the conveying direction, which overlaps at least the at least two extraction devices, and transported in a transport direction separate from the shards to the at least two extraction devices, wherein the shards and the raw material mixture are brought together in the transport direction in and / or behind the distribution chamber as well as in and / or behind an outlet of the first storage container in the respective extraction device.

[0045] The advantages and specific embodiments will become apparent with respect to the device according to the invention. For example, a device according to the invention can be configured to carry out the method according to the invention. Similarly, the method according to the invention can be carried out using the device according to the invention or its embodiments.

[0046] Preferably, the raw material mixture is fed to the at least two dispensing devices via the distribution chamber. Within the distribution chamber, the raw material mixture is distributed across its entire width, which overlaps the at least two dispensing devices. Particularly with a low conveying capacity of the dosing device, this can enable more reliable and / or precise control of the raw material mixture's distribution to the at least two dispensing devices.

[0047] Preferably, the at least two extraction devices are each operated with the same conveying capacity for the molten material. This simplifies the control and regulation of the device and also ensures a uniform distribution of the molten material at the inlet of the glass melting plant.

[0048] According to a further embodiment of the method according to the invention, the at least two extraction devices are operated with a total conveying capacity that is higher than the conveying capacity with which the metering device adds the raw material mixture. This ensures that the raw material mixture is discharged from the distribution chamber by the at least two extraction devices so quickly that no undesirable accumulation of the raw material mixture occurs in the distribution chamber and / or in the metering device. Particularly preferably, the total conveying capacity of the at least two extraction devices is at least one and a half times, more preferably at least three times, and most preferably at least four times the conveying capacity of the metering device.

[0049] It has proven advantageous for at least three adjacent extraction devices to convey the bulk material parallel to each other from the outlet section of the device to the inlet of the glass melting plant along the conveying direction, wherein the distribution chamber receives the raw material mixture across the width of the device transversely to the conveying direction, which overlaps at least the three extraction devices, and transports it separately from the cullet to the three extraction devices in the transport direction.

[0050] In a further development of the inventive method, the total conveying capacity of the bulk material is controlled by measuring a level of the molten glass in the glass melting plant using a level probe and by adjusting the conveying speed of the at least two extraction devices.

[0051] The invention is explained below with reference to exemplary embodiments and the figures. All features described and / or illustrated, individually or in any combination, constitute the subject matter of the invention, even independently of their compilation in the claims or their cross-references.

[0052] They show schematically: Fig. 1 A first embodiment of a device according to the invention for feeding glass melting plants with bulk material consisting of cullet and raw material mixture in a longitudinal section, Fig. 2a the embodiment according to Fig. 1 in a cross-section along the cross-sectional plane AA (see Fig. 1) with a deflector in a first rotation position, Fig. 2b the embodiment according to Fig. 1 in a cross-section along the cross-sectional plane AA (see Fig. 1) with a deflector in a middle, second rotation position, Fig. 2c the embodiment according to Fig. 1 in a cross-section along the cross-sectional plane AA (see Fig. 1) with a deflector in a further, third rotational position, Fig. 2d a second embodiment of a device according to the invention along the in the Fig. cross-sectional plane shown in 2a to 2c, Fig. 3 a third embodiment of a device according to the invention in a perspective view cut along a longitudinal direction, Fig. 4 a rule scheme for the in Fig. Exemplary embodiment shown in 1 and 2a to 2c, Fig. 5 a fourth embodiment of a device according to the invention for feeding glass melting plants with bulk material consisting of cullet and raw material mixture in a longitudinal section and Fig. 6 a fifth embodiment of a device according to the invention for feeding glass melting plants with bulk material consisting of shards and raw material mixture in a longitudinal section.

[0053] The in Fig. Figure 1, the first embodiment of a device according to the invention, comprises a first storage container 10, which receives the shards 4, and a second storage container 20, which receives the raw material mixture 5. The mixture of the shards 4 and the raw material mixture 5 is hereinafter referred to as bulk material or melt material.

[0054] Three adjacent extraction devices 3 convey the bulk material parallel to each other from an outlet section 2 of the device along a conveying direction 33 to an inlet of a glass melting plant (see Fig. 4). In the Fig. In the longitudinal section shown in section 1, only one of the three extraction devices 3 is visible, in which Fig. In contrast, all three extraction devices 3 are visible in 2a to 2c. They are arranged side by side in a row below the lower end of the outlet section 2, transverse to the conveying direction 33. The outlet section 2 of the device comprises an outlet 11 of the first storage container 10 and a distribution chamber 26 for the raw material mixture 5, and opens into the extraction devices 3 arranged side by side.

[0055] The first storage container 10 has a heat exchanger (not shown) to which hot exhaust gases from the glass melting plant are fed in a counterflow configuration. The heat from these exhaust gases preheats the cullet 4 in the first storage container 10. The cullet 4, added from above into the first storage container 10, slide downwards due to gravity and pass through the outlet 11 of the first storage container 10 into the three discharge devices 3. From the three discharge devices 3, the cullet 4 is conveyed in the conveying direction 33 to the inlet(s) of the glass melting plant (not shown).

[0056] The raw material mixture 5 is fed from above into the second storage container 20. From there, it slides downwards due to gravity into an outlet 21 of the second storage container 20 and from there into a metering device 22. The metering device 22 comprises, for example, a screw conveyor 23 driven by a drive unit 24. The drive unit 24 has a motor, for example, an electric motor. It may also include a gearbox. The metering device 22 forcefully conveys the raw material mixture 5 from the outlet 21 of the second storage container 20 to the distribution chamber 26 of the outlet section 2 of the device. Alternatively, a vibrating trough or a closed vibrating tube can also be used in the metering device 22.

[0057] Through a metering outlet 25, which forms an outlet opening from the metering device 22 towards the distribution chamber 26, the raw material mixture 5 enters the distribution chamber 26 from the screw conveyor 23 and falls downwards due to gravity along a transport direction. The transport of the raw material mixture 5 in the distribution chamber is described below using the Fig. 2a to 2d are explained in more detail.

[0058] Each of the three extraction devices 3 extends, opposite to its conveying direction 33, along a lower end of the outlet 11 of the first storage container 10, or along a lower end of the outlet section 2 and along an outlet of the distribution chamber 26. Each extraction device 3 has a screw conveyor 31 driven by a drive unit 32. Alternatively, a vibrating trough or vibrating tube can be used to transport the bulk material. The drive unit 32 comprises a motor and can also include a gearbox if required. The distribution chamber 26 is separated from the outlet 11 of the first storage container 10 above the extraction devices 3. Viewed in the conveying direction 33 and in the transport direction of the raw material mixture 5, it is located upstream of the outlet 11 of the first storage container 10.The distribution chamber 26 therefore transports the raw material mixture 5 separately from the shards 4 to the three extraction devices 3. As shown in the diagram. Fig. As can be seen in Figures 1 to 2c, the distribution chamber 26 is shaped as a separate, essentially box-shaped container, sealed off from the environment. The container is located in the area of ​​the outlet section 2 next to the outlet 11 of the first storage container 10 and above the three dispensing devices 3.

[0059] As soon as raw material mixture 5 enters one of the discharge devices 3, it is conveyed by the respective screw conveyor 31 to the outlet 11 of the first storage container 10. At outlet 11, the cullet 4 also slide into the screw conveyors 31 of the discharge devices 3 due to gravity. As they continue along the screw conveyor 31, the cullet 4 mix with the raw material mixture 5 already present in the conveyor. Thus, in the lowest section of outlet 11 of the first storage container 10, or outlet section 2, the raw material mixture 5 and the preheated cullet 4 are mixed together in the specified ratio within the discharge devices 3. The resulting bulk material is then conveyed by the discharge devices 3 to the inlet(s) of the glass melting plant.

[0060] Based on the Fig. Sections 2a to 2c now explain the operation and construction of the distribution chamber 26. The width of the distribution chamber 26 corresponds to the total width of all adjacent extraction devices 3. The height of the distribution chamber is preferably designed such that a distribution device (40) of sufficient length moving within it can perform a cyclic (rotary) movement so that the material flow (here, the raw material mixture 5) can also be transported towards the two outermost, opposing extraction devices 3. The distribution device 40 provided in the distribution chamber 26 comprises a deflector 41 designed as a plate-shaped element (e.g., an elongated flat iron or an element suitably profiled at the ends), which is divided into three sections about a pivot axis 44. Fig. The rotary positions shown in 2a to 2c are rotatable. A width B of the deflector 41 along the axis of rotation 44, which runs parallel to the conveying direction 33, is defined according to Fig. 1 slightly less than the depth of the distribution chamber 26 in the same direction, so that sufficient mechanical clearance remains for rotation of the deflector 41 about the axis of rotation 44. A distance of at least 10 mm to the inside of the side wall 26a is sufficient; preferably, a distance of at least 5 mm to the side wall 26a is preferred (see Fig. 2a to 2d).

[0061] From the metering outlet 25 of the metering device 22, which is preferably located directly above the axis of rotation 44 of the distribution device 40, the raw material mixture reaches the deflector 41. The deflector 41 is continuously rotated or pivoted about the axis of rotation 44 and thereby distributes the raw material mixture 5 evenly across the entire width of the distribution chamber 26, the width of which is selected such that it extends over all the dispensing devices 3. The axis of rotation 44 of the deflector 41 is arranged along the deflector 41. The distribution of the raw material mixture is described in more detail below.

[0062] In Fig. 2b, the deflector 41 is in a middle, second position. In this second position, the deflector 41 is oriented approximately vertically, meaning that the plate-shaped element runs parallel to the direction of gravity. In this state, it does not deflect the raw material mixture 5 that has exited the metering outlet 25 and is falling into the distribution chamber 26. The raw material mixture 5 falls vertically towards the middle extraction device 3 or the middle area of ​​the distribution chamber 26.

[0063] However, if deflector 41 is located in the Fig. In the first rotational position shown in 2a, the deflector 41 blocks the raw material mixture from falling downwards from the metering outlet 25 towards the central dispensing device 3. Since the deflector 41 in the first rotational position is opposite the Fig. In the second rotation position shown in 2b, the raw material mixture 5 exiting the metering outlet 25 is rotated 45° counterclockwise around the axis of rotation 44. Fig. 2a onto the inclined deflector 41 and is diverted transversely to the conveying direction 33 in the direction of the right extraction device 3 or the right part of the distribution chamber 26.

[0064] In Fig. In position 2c, the deflector 41 is in a third rotational position, in which it is rotated 45° clockwise around the axis of rotation 44 relative to the second rotational position. In this rotational position, the raw material mixture 5 exiting the metering outlet 25 falls onto the inclined deflector 41 and is diverted transversely to the conveying direction 33 towards the left extraction device 3 or the left part of the distribution chamber 26.

[0065] As in Fig. As can be seen in Figure 1, the deflector 41 is driven by a motor 42 via a gearbox 43 and can thus be continuously rotated or pivoted between the three described rotary positions. The motor 42 can be, for example, an electric motor. It is also possible that the motor 42 contains the gearbox 43 or that the deflector 41 is driven directly by the motor 42 without a gearbox. By switching between the described rotary positions, the distribution chamber 26 receives the raw material mixture 5 over a width 28 of the device transverse to the conveying direction 33, which overlaps the three discharge devices 3. The total width 28 is approximately 1500 to 2500 mm. By means of a suitable rotational speed (0.25 s -1 up to 0.025 s -1The deflector 41 distributes the raw material mixture 5 evenly to the three discharge devices 3 on average over time. The specified rotational speed means that the deflector 41 requires 1 to 10 seconds to move between its first and third rotational positions. Consequently, if the screw conveyors 31 of each of the three discharge devices 3 are operated at the same speed, the same average mass of raw material mixture is conveyed per unit of time to the inlet of the glass melting plant.

[0066] Alternatively, in a second embodiment of the device according to the invention, the distributor device 40 can be, as shown in Fig. The vibratory distributor 46 is shown in Figure 2d. It is arranged in the distribution chamber 26 and connected, for example, via a rod to a vibration device located outside the distribution chamber 26. The vibration device causes the vibratory distributor 26 to move back and forth transversely (perpendicularly) to the direction of transport of the raw material mixture (perpendicular to the plane of the Fig. 2d). The particles fall from the metering outlet 25, which is located above the vibrating distributor 26, onto the oscillating vibrating distributor 46. It disrupts the direct vertical discharge of the material and ensures that the particles of the raw material mixture 5 impact the lower end of the distribution chamber 26 over a larger area.

[0067] Preferably, the three extraction devices 3 are each operated with a conveying capacity that is equal to or higher than the conveying capacity of the metering device 22. This prevents the raw material mixture 5, which is forcibly conveyed by the metering device 22, from accumulating excessively in the distribution chamber 26 and thus causing problems in the operation of the device.

[0068] Fig. Figure 3 shows a third embodiment of a device according to the invention. The construction and operation are essentially the same as those of the device described in the Fig. The first embodiment is illustrated in Figures 1 to 2c. The same reference numerals are used for identical elements. The device of the second embodiment also has three removal devices 3, of which the cutaway view in Figure 1 to 2c shows three removal devices 3. Fig. However, only two are visible. The ones in Fig. The device shown in Figure 3 differs from the one described above in that the metering device 22 has a vibrating tube 23' instead of a screw conveyor 23. The vibrating tube 23' opens into the distribution chamber 26' at a metering outlet 25'. Another difference is that the distribution chamber 26' is separated from the outlet 11 of the first storage container 10 in the outlet section 2 only by a partition 27. The partition is also made of a heat-resistant steel alloy and is intended to ensure that the flow of raw material mixture 5, which is filled into the distribution chamber 26, does not impede the flow of cullet 4. Furthermore, the axis of rotation (in Fig. 3 not shown) of the deflector 41 not parallel to the conveying direction 33.

[0069] In the Fig. In the embodiments of the invention shown in Figures 1 to 2c and 3, three dispensing devices 3 each contribute equally to conveying the raw material mixture 5 towards the inlet of the glass melting plant. This enables a higher overall conveying capacity of molten material to the glass melting plant compared to a device with only one dispensing device. Nevertheless, in both embodiments, only a single metering device 22 is required for the raw material mixture 5, since the raw material mixture 5 is distributed evenly across all three dispensing devices 3. This reduces the complexity, costs, and space requirements for feeding the bulk material. Furthermore, the even distribution of the raw material mixture 5 across the three dispensing devices 3 results in a more even distribution of the raw material mixture 5 in the molten glass of the glass melting plant.

[0070] Furthermore, in both embodiments, the flows of the raw material mixture 5 and the preheated cullet 4 are kept separate from each other until they are combined directly above or within the three dispensing devices 3 in the outlet 11 of the first storage container 10. The raw material mixture 5 remains cold and thus free-flowing before being combined with the preheated cullet 4. This facilitates the reliable and uniform distribution of the raw material mixture 5 to the three dispensing devices 3.

[0071] The Fig. 5 and Fig. Figure 6 shows further embodiments of the feeding device according to the invention.

[0072] The in Fig. The device shown in section 5 corresponds to the device according to Fig. 1, however, here the distribution chamber 26 is arranged at a distance D (advantageously between 100 mm and 2000 mm) in the conveying direction 33 from the outlet 11 of the first storage container 10. The feed of the raw material mixture into the main stream containing the cullet is spatially separated from the first storage container 10 for the cullet. In the case that the cullet has been heated and the raw material mixture tends to stick and clump together even with slight heating, this embodiment of separate mixing is advantageous.

[0073] The embodiment described in Fig. The embodiment shown in Figure 6 also corresponds to the first embodiment, with the difference that the second storage container 20, the metering device 22, and the distribution chamber 26 with distributor 40 are now arranged behind the first storage container 10 in the conveying direction 33 and in the transport direction. In all embodiments, when a vibratory feeder is used as the discharge device, a specific stratification of both material streams is achieved by arranging the feed of the raw material mixture and the cullet one after the other in the transport direction and conveying direction, respectively. In the case of the arrangement of Fig. In step 6, the raw material mixture 5 comes to rest on the cullet 4. When this mixture is conveyed into the glass melting plant, the raw material mixture 5 is exposed more directly to radiant heat.

[0074] In Fig. Figure 4 is a control scheme for a feeding device according to the invention as described in Figure 4. Fig. The embodiment shown in Figures 1 and 2a to 2c is illustrated. The feeding device includes a control and regulating unit 50, which contains a microprocessor for data processing.

[0075] The raw material mixture 5, which is added to the glass cullet 4, is stored in the second storage container 20. The quantity of raw material mixture 5 contained in the second storage container 20 corresponds approximately to a day's requirement. The withdrawal from the second storage container 20 is continuously monitored by the control unit 50 and adjusted by controlling the conveying speed of the dosing device 22. The weight loss of the entire second storage container 20 (including the weight of the container itself) is detected by pressure sensors 29 in the supporting structure for the second storage container 20 and transmitted as input to the control unit 50. The target quantity for the withdrawal of raw material mixture 5 corresponds exactly to the desired percentage of raw material mixture 5 relative to the total quantity of glass to be produced.The amount of molten glass removed (see arrow 48 in . Fig. 4) The amount of glass produced is, for example, monitored via the gap size of the outlet at the end of the melting vessel of the glass melting plant 7 and preferably controlled by the control unit 50. The quantity of glass produced is measured. Deviations from the target value are used to correct the gap size. The fill level in the melting vessel is also continuously monitored, i.e., measured and preferably also controlled, by means of a fill level measuring device 49. The glass level is measured, and deviations from the target are controlled by regulating the conveying speed of the discharge devices 3 such that a constant fill level in the melting vessel is maintained. Reference symbol list: 2 Initial section 3. Extraction device 4 shards 5 Raw material mixture 7 Glass melting plant 10 first storage container 11. Outlet of the first storage container 10 20 second storage containers 21. Outlet of the second storage container 22 Dosing device 23 screw conveyors 23' Vibration tube 24 drive unit 25, 25' Metering outlet 26, 26' Distribution Chamber 26a Side wall of the distribution chamber 27 dividing bridge 28 width 29 Pressure sensor 31 screw conveyors 32 Drive unit 33 Direction of conveyance 40 distribution device 41 deflectors 42 Engine 43 gearboxes 44 axis of rotation 46 vibration distributors 47 Glass melting 48% of molten glass removed 49 Level measuring device 50 Control and regulating device B Width of the deflector 41 in the direction of the axis of rotation 44 D Distance of the distribution chamber 26 from the outlet 11 of the first storage container 10

Claims

[1] Device for feeding a glass melting plant with bulk material consisting of cullet (4) and raw material mixture (5), comprising a first storage container (10) for the shards (4) and a second storage container (20) separate from the first storage container (10) for the raw material mixture (5) and an output section (2), wherein the output section (2) has a distribution chamber (26, 26'), and at least two adjacent extraction devices (3) in the form of a conveying means, each comprising a screw conveyor, a vibrating trough or a vibrating tube, wherein the at least two adjacent extraction devices each convey the bulk material parallel to each other from the discharge section (2) to an inlet of the glass melting plant along a conveying direction (33), wherein the device has a metering device (22) connected to the second storage container (20), which forcibly conveys the raw material mixture (5) from the second storage container (20) into the distribution chamber (26, 26') of the outlet section (2), wherein the distribution chamber (26, 26') receives the raw material mixture (5) over a width (28) of the device transverse to the conveying direction (33), which overlaps at least the at least two extraction devices (3), and transports it in a transport direction separate from the shards (4) to the at least two extraction devices (3), wherein the shards (4) and the raw material mixture (5) are brought together in the transport direction in and / or behind an outlet of the distribution chamber (26, 26') and in and / or behind an outlet (11) of the first storage container (10) in the respective extraction device (3). [2] Device according to claim 1, characterized by, that the outlet of the distribution chamber (26, 26') is located in front of the outlet (11) of the first storage container (10) with respect to the conveying direction (33). [3] Device according to one of claims 1 and 2, characterized by , that the distribution chamber (26') is delimited by a partition (27) and separated from the outlet (11) of the first storage container (10) or that the distribution chamber (26) is formed by a substantially box-shaped container. [4] Device according to one of claims 1 or 2, characterized by , that a distribution device (40) is arranged in and / or on the distribution chamber (26, 26') which distributes the raw material mixture (5) supplied from the metering device (22) evenly over the entire width of the distribution chamber (26, 26'). [5] Device according to claim 4, characterized by , that the distributor device (40) has a deflector (41) which can be rotated about a pivot axis (44) into at least two different rotational positions, wherein preferably a metering outlet (25, 25') of the metering device (22) opens into the distribution chamber (26, 26') in front of the deflector (41) with respect to the transport direction and directs the raw material mixture (5) in the direction of the deflector (41). [6] Device according to any one of the preceding claims, characterized by, that at least three adjacent extraction devices (3) each convey the bulk material parallel to each other from the outlet section (2) to the inlet of the glass melting plant along the conveying direction (33) and that the distribution chamber (26, 26') receives the raw material mixture (5) across the width (28) of the device transverse to the conveying direction (33), which overlaps at least the at least three extraction devices (3), and transports it in a transport direction separate from the cullet (4) to the at least three extraction devices (3). [7] Method for feeding a glass melting plant with bulk material consisting of cullet (4) and raw material mixture (5), wherein a first storage container (10) receives the shards (4) and a second storage container (20) separate from the first storage container (10) receives the raw material mixture (5), wherein the bulk material is conveyed by means of two adjacently arranged extraction devices (3) in the form of a conveying means, each comprising a screw conveyor, a vibrating trough or a vibrating tube, wherein the bulk material is conveyed by the two adjacently arranged extraction devices parallel to each other from an outlet section (2) of the device to an inlet of the glass melting plant along a conveying direction (33), wherein the raw material mixture (5) is forcibly conveyed from the second storage container (20) into a distribution chamber (26, 26') of the output section (2) by means of a metering device (22) connected to the second storage container (20), wherein the raw material mixture (5) is received by the distribution chamber (26, 26') over a width (28) of the device transverse to the conveying direction (33), which overlaps at least the at least two extraction devices (3), and is transported in a transport direction separately from the shards (4) to the at least two extraction devices (3), wherein the shards (4) and the raw material mixture (5) are brought together in the transport direction in and / or behind an outlet of the distribution chamber (26, 26') and in and / or behind an outlet (11) of the first storage container (10) in the respective extraction device (3). [8] Method according to claim 7, characterized by , that the raw material mixture (5) is fed to the at least two extraction devices (3) by means of the distribution chamber (26, 26'). [9] Method according to one of claims 7 or 8, characterized by, that the at least two extraction devices (3) are operated with a total conveying capacity that is higher than a conveying capacity with which the metering device (22) doses the raw material mixture (5). [10] Method according to any one of claims 7 to 9, characterized by , that at least three adjacent extraction devices (3) each convey the bulk material parallel to each other from the outlet section (2) to the inlet of the glass melting plant along the conveying direction (33), wherein the distribution chamber (26, 26') receives the raw material mixture (5) across the width (28) of the device transverse to the conveying direction (33), which overlaps at least the at least three extraction devices (3), and transports it in the transport direction separately from the cullet (4) to the at least three extraction devices (3).

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