Slag separation device and method

Abstract

A hopper (30) for separating slag from a mixture of product and slag, and a system and method for using such a hopper are provided. Each hopper includes: an inner gate (32) configured to prevent product from passing through but allow slag to pass through; and an outer gate (34) configured to prevent product from passing through and slag to pass through; the inner gate and the outer gate are movable between respective open and closed positions; the hopper is configured so that: when the inner gate and the outer gate are in their respective closed positions and the mixture is introduced into the hopper, the product is retained by the inner gate, while the slag passes through the inner gate and is retained by the outer gate; and when the outer gate and the inner gate are each in their respective open positions, the product can leave the hopper along a first path.

Description

Technical Field

[0001] The present disclosure relates to an apparatus, system and method for separating excess slack from a product stream comprising a mixture of product and slack. For example, the slack may be a food product covering, such as sugar for sugary candies, bread crumbs for bread products, or seasoning for savory snacks.

[0002] More specifically, aspects of the invention relate to an improved hopper design and systems and methods for using the same. The apparatus and methods according to the invention are particularly suitable for use in the food packaging industry. Background Art

[0003] Some products are packaged with additional materials, which will be referred to herein as crumbs. Crumbs, which are typically in substantially solid or liquid form, may be mixed with the solid product prior to dispensing the mixture into the package. If the crumbs are substantially solid, they are significantly smaller in size than the product itself, often at least five times smaller, more typically at least an order of magnitude smaller (i.e., ten times smaller). For example, the crumbs may be in the form of a powder or granules.

[0004] Crumbs may be included in the product packaging to protect the product in some way, for example, to prevent degradation due to exposure to certain chemicals or due to movement of the product in its packaging. Alternatively or additionally, crumbs may be included to strengthen the product in some way, for example, a food product may be provided with a loose coating of sugar, breadcrumbs or herbs to improve the taste, texture and / or appearance of the food product. Alternatively or additionally, crumbs may be generated during the handling of the product prior to packaging, for example, a product such as French fries or potato chips may be crushed or broken to form crumbs in the form of crumbs.

[0005] Additionally, in some processes (e.g., coating processes), it may be necessary to mix a higher proportion of crumbs into the product than is desired in the final packaged product, e.g., to ensure that a uniform coating can be achieved. However, this raises the question of how to separate the excess crumbs from the product before packaging.

[0006] However, for some products, it is undesirable to allow excess crumbs to float freely within the package. For example, if excess bread crumbs float in the package of a bread product intended for oven cooking, the excess crumbs may eventually burn on the oven tray. Separating the excess crumbs before packaging helps solve these problems.

[0007] Another problem occurs when a mixture of product and crumbs is poured into a package and the upper end of the package is then sealed. If the crumbs fall at a slower rate than the product (e.g., the product is a gel candy and the crumbs are icing), the crumbs (sugar) trapped within the seal may compromise the quality of the seal. To reduce this problem, the sealing step can be delayed to allow the crumbs to settle before sealing, but this approach slows the process and reduces the yield of packaged product.

[0008] Excess debris may also accumulate or become lodged in produce handling machinery. This may cause the machinery to become stuck. Similarly, where produce handling machinery is used to produce food products, debris that becomes lodged in machinery over a long period of time may cause it to spoil or attract pests, thus endangering public health.

[0009] Therefore, there is a need for an alternative method and / or apparatus for separating excess slag from a product stream that preferably helps to address one or more of the problems discussed above. Summary of the invention

[0010] The claimed invention provides an improved apparatus, system and method for removing crumbs from a product stream. Specifically, the apparatus and system according to the invention include a hopper that can be used to store, weigh and discharge a product having a reduced crumb level. For example, when used in the food industry, the claimed invention is applicable to, but not limited to, separating bulk sugar from sugary candies; separating excess seasoning and crumbs from potato chips or French fries; separating bread crumbs from bread products; and separating excess marinade from raw meat products.

[0011] As used herein, "crumbs" will be understood to include liquids and / or solids of a size that is significantly smaller than the size of the product (e.g., food product) in the product stream. Likewise, solid crumbs or solids in crumbs that contain both liquids and solids can be separated or distinguished from the product based on size. For example, the solid crumbs may be in the form of a powder or granules, while the product may be much larger. The solid crumbs may have a size that is at least five times smaller, and more typically ten times smaller, than the size of the product in the mixture of product and crumbs.

[0012] According to one aspect of the present invention, a hopper for separating slag from a mixture of product and slag is provided, the hopper comprising: an inner gate configured to prevent product from passing through but allow slag to pass through; and an outer gate configured to prevent product from passing through and to prevent slag from passing through; the inner gate and the outer gate are movable between respective open and closed positions; the hopper is configured such that: when the inner gate and the outer gate are in their respective closed positions and the mixture is introduced into the hopper, the product is retained by the inner gate while the slag passes through the inner gate and is retained by the outer gate; and, when the outer gate and the inner gate are each in their respective open positions, the product can leave the hopper along a first path.

[0013] Using such a device to remove excess debris from the product stream increases the reliability of the product handling system and improves the quality of the final product.

[0014] Furthermore, it will be appreciated that the present invention provides a particularly quick and effective means of removing scraps from a product flow. The hopper according to the present invention is particularly space-saving, since components (i.e. internal gates) for separating or separating the scraps from the product can be provided inside the hopper. Furthermore, the hopper according to the present invention can be easily retrofitted to product handling machinery, replacing existing hoppers which may not be suitable for separating scraps from a product flow.

[0015] Additionally, the slag can be removed from the product flow as the product settles in the hopper and without significantly delaying discharge of the product from the hopper. Thus, the slag can be removed from the product flow without significantly affecting the throughput of the hopper and / or the output of the wider system.

[0016] If the inner gate and the outer gate are each in their respective closed positions, i.e., with the inner gate in its closed position and the outer gate in its closed position, the hopper will separate the crumbs from the product. When the hopper is in this arrangement, the product introduced into the hopper will be retained (i.e., held or captured) by the closed inner gate. In contrast, at least a portion of the crumbs will pass through the closed inner gate (e.g., under the action of gravity). Thus, the product captured by the inner gate is separated or separated from the crumbs that have passed through the inner gate.

[0017] The slag that passes through the closed inner gate will then be retained or captured by the closed outer gate that may be located below the inner gate. The separated slag can then be collected or discharged for collection separately from the product. The collection of slag can be performed manually (i.e. by hand) or automatically by an apparatus and / or a wider system.

[0018] Excess slag separated and collected using the device can be reused and reintroduced into the production line upstream of the device to reduce waste.

[0019] The product (and any remaining scraps) retained by the closed inner gate may then be discharged or allowed to exit the hopper by opening the inner gate and the outer gate - ie moving the inner gate and the outer gate to their respective open positions.

[0020] The amount of slag removed from the mixture of product and slag by the hopper may depend on the length of time the mixture spends in the hopper (i.e., the "residence time" of the product in the hopper). Similarly, the proportion of slag removed by the hopper may depend on the specific product and slag in question. For example, in a preferred embodiment, at least 15% of the slag may be removed from the mixture introduced into the hopper, more preferably 25%, even more preferably 50%, even more preferably 75%.

[0021] It is particularly beneficial to remove crumbs from a mixture of product and crumbs at the hopper compared to other stages of the production line. This is because the product may experience significant falling or falling into the hopper (e.g. from a product feeding device such as a dispersed feeder, a screw feeder, a conveyor belt or any other suitable machine). When the product hits or collides with the hopper, this falling may generate a large amount of crumbs. Therefore, the device according to the present invention can quickly remove crumbs after the crumbs are generated and before they are transferred to a downstream product processing machine or before the product is distributed into a package of a packaging machine. In particular, before the food product is distributed into a package of a packaging machine, it is desirable to provide a crumb removal hopper as a final hopper. This is because crumbs are usually generated each time the product hits or collides with a surface such as the inside of the hopper. Therefore, a single crumb removal hopper provided as the final hopper before packaging can be used to remove all crumbs on the last occasion where significant crumbs are generated, thereby minimizing the amount of crumbs in the final packaged product. For example, the crumb removal hopper can distribute the product along a first path, which first path can directly or indirectly lead to the package of the packaging machine. For example, the product may drop directly from a hopper into the package, or may be conveyed along one or more funnels or chutes into the package.

[0022] The inner gate and / or the outer gate can be moved between their respective open positions and closed positions by rotating around hinges (e.g., corresponding hinges). Alternatively, the gates can slide between their respective open positions and closed positions.

[0023] Preferably, the hopper is configured so that when the outer gates are in their respective closed positions, a second path is provided for the debris retained by the outer gates to exit the hopper, the second path being different from the first path. Thus, debris separated from the product by the inner gates is removed or collected from the hopper via the second path (e.g., through an aperture or debris collection conduit defined by the hopper). Such removal or collection may occur automatically—i.e., without human intervention. Because the second path is different from the first path, the debris does not re-enter the product flow and does not interfere with downstream product handling equipment. Thus, the reliability of a system including the hopper and the quality of the product output by the system may be improved.

[0024] For example, the hopper may be configured so that the slag leaving the hopper along the second path may enter a storage container (or other container). Such a storage container may be emptied periodically or continuously as needed (e.g., so that the slag can be reintroduced into the product line upstream of the hopper).

[0025] In some embodiments, the second path may be inclined relative to the first path and / or laterally offset from the first path. "Inclined" is understood to mean that the second path is inclined from the first path and extends in a direction that is not parallel to the direction in which the first path extends. However, in alternative embodiments, the separated slag may be discharged or collected from the hopper along the same path as the product (i.e., along the first path), as will be discussed further below.

[0026] Preferably, the lower end of the outer gate includes a groove configured to receive debris when the outer gate is in its respective closed position. For example, debris separated from the product by the inner gate may fall to the outer gate under the action of gravity and accumulate or collect in the groove. The provision of a groove (e.g., a groove or slot) formed in or on the outer gate simplifies the collection and removal of debris.

[0027] In addition, the slot can help prevent inadvertent ejection of chips from the hopper when the outer gate moves from its open position to its closed position (or vice versa). Thus, a hopper having such a slot is more effective in preventing chips from passing through another product handling machinery and can be incorporated into a system for improved reliability.

[0028] Preferably, the hopper is configured so that when the outer gate is in its closed position, the slag can travel along the slot and exit the hopper along a second path. For example, the second path may extend through a hole or gap in the side wall of the hopper adjacent to the slot when the outer gate is in the closed position, or may extend through a duct or tube extending from the hopper. In a further preferred embodiment, the device may be configured so that when the outer gate is in either of its respective open or closed positions, the slag can travel along the slot and exit the hopper (e.g., under gravity or suction).

[0029] In some embodiments, the bottom of the trough may be inclined so that the slag can travel along the bottom of the trough under the action of gravity. It will be understood, therefore, that the bottom of the trough is not parallel to the horizontal axis or the vertical axis when in use. Therefore, the slag (especially the slag in the form of liquid or fine particles) can flow along the bottom of the trough and can leave the hopper along the second path. The slag can be easily collected at the lower end of the trough or can continue to flow out of the hopper along the second path (for example, through a gap or hole in the hopper or through a slag collection pipe defined by the hopper). However, in further embodiments, the trough may include a bottom that is not inclined - that is, the hopper may include a trough having a bottom that extends in a substantially horizontal direction when in use.

[0030] Additionally or alternatively, the hopper is configured to be connected to a vacuum pump configured to collect the debris that leaves the hopper along the second path. In this way, excess debris that has been separated from the product by the inner gate and retained by the outer gate can be quickly and easily removed from the hopper. For example, the hopper can be configured so that when the gate is at least in its closed position, a suction force from the vacuum pump can be applied at or near the outer gate to collect the debris retained by the outer gate.

[0031] In a preferred configuration, the vacuum pump can be configured to be connected to a trough formed in the lower end of the outer gate as discussed above. In these embodiments, the slag can travel along the bottom of the trough and leave the hopper under the suction force provided by the vacuum pump - that is, the vacuum pump can pull the slag along the trough and pull the slag out of the hopper along a second path. Preferably, the vacuum pump is connected to the lower end of the trough with an inclined bottom so that the slag that has flowed or traveled along the bottom of the trough can be easily collected and transferred elsewhere (e.g., reintroduced into an upstream production line).

[0032] Alternatively or additionally, the hopper may be configured so that the separated crumbs can be collected manually or can flow from the hopper under gravity. In a further embodiment, the hopper may be configured so that the outer gate is moved to its open position while the inner gate remains closed so that the separated crumbs can be discharged from the hopper while the product is retained by the inner gate.

[0033] Preferably, the hopper is configured to be connected to a tube through which the second path extends. Here, the term "tube" refers to a conduit of any shape for conveying slag out of the hopper, but typically the cross-section of the tube will be cylindrical. The tube can be rigid or flexible as desired. A "rigid" tube is a tube that does not deform substantially when subjected to forces associated with use, while a "flexible" tube may deform or bend when forces are applied. Rigid tubes can be made of materials such as metal or hard plastic and are relatively easy to clean and generally have a longer life. On the other hand, flexible tubes can accommodate high levels of vibration or movement of components of the hopper without breaking or disconnecting from the hopper. The flexible tube can be formed of natural or synthetic rubber (e.g., silicone) or any other suitable material. The tube can be permanently connected to the hopper, but in preferred embodiments, it can be removable or selectively removable (e.g., for maintenance or cleaning).

[0034] In a preferred embodiment, the tube is configured to be connected to the outer gate. In the case where the tube is flexible, the upstream end of the flexible tube can move as the outer gate moves between its open position and closed position, and the downstream end can be connected to a fixed pipe into which the slag is transported. In the case where the tube is rigid, the entire tube can move as the outer gate moves between its open position and closed position, and the pipe can be arranged with an opening that matches the path through which the rigid tube moves, so that all the slag passing through the rigid tube is received by the pipe. In an embodiment where the hopper includes a groove formed at the lower end of the outer gate, the tube can be configured to be connected to the groove or communicate with the groove. Therefore, the slag separated by the inner gate and retained by the outer gate can travel or flow along the groove and enter the tube for removal. In a particularly preferred embodiment, whether the outer gate is in its open position or closed position, the slag received in the groove can be removed from the hopper in this way. Therefore, the slag can be removed from the hopper more effectively without delaying the operation of the hopper (i.e., discharging the product by the hopper).

[0035] Additionally or alternatively, the hopper may be configured to be connected to the vacuum pump via a tube. In other words, the tube may be configured to be connected to the hopper at a first end and to the vacuum pump at a second end. Thus, a suction force from the vacuum pump may be applied to the hopper via the tube, so that the slag separated by the inner gate may be collected along a second path extending through the tube.

[0036] The tube may be integrally formed with the hopper and / or may be permanently connected to the hopper (eg, with an adhesive). However, in a preferred embodiment, the hopper is configured to be removably connected to the tube - for example, so that the tube can be removed for cleaning or maintenance.

[0037] For example, the hopper may include a rigid scrap collection conduit, wherein the hopper is connected to the tube via the rigid scrap collection conduit. Thus, the hopper may be configured such that the tube can be inserted into the scrap connection conduit and / or such that the scrap connection conduit can be inserted into the flexible tube. Thus, the tube can be easily and quickly connected to the hopper simply by pushing the tube onto or into the end of the rigid scrap connection conduit.

[0038] Thus, the slag connection conduit can transfer the slag from the hopper to the tube. The slag can leave the hopper along a second path through both the rigid slag connection conduit and the tube. The slag connection conduit can be formed as a tube or an open channel (but is not limited to these forms). Alternatively, any other means of connecting the tube to the hopper can be provided.

[0039] In a further alternative embodiment, the hopper may include a rigid slag collection conduit through which the separated slag leaves the hopper and can be collected without the need for a tube to direct the slag out of the hopper. For example, the slag collection conduit may feed the separated slag directly into a storage container.

[0040] In the above embodiment where the slag can leave the hopper via the second path, the inner gate and the outer gate can be configured to move between their respective open and closed positions simultaneously (e.g., in tandem). For example, the hopper can be configured so that the inner gate is fixed relative to the outer gate. In such an embodiment, the inner gate and the outer gate, which are rigidly connected (e.g., by screws, adhesives, or welding), will move in tandem simultaneously.

[0041] However, this is not required, and in further embodiments, the hopper can be configured so that the positions of the inner gate and the outer gate can be controlled separately (so that the outer gate and the inner gate can be opened and closed independently). In other words, the inner gate and the outer gate can be hinged separately.

[0042] The hopper may be configured to move the outer gate between its respective closed and open positions independently of the inner gate, such that when the outer gate is in its respective open position and the inner gate is in its respective closed position, the crumbs may exit the hopper in the first direction while the product is retained by the inner gate. Thus, by opening the outer gate instead of opening the inner gate, excess crumbs separated from the product by the inner gate may be discharged in the first direction separately from the product (i.e., at a different time).

[0043] In such an embodiment, the hopper can be configured to alternately release the product and the excess slag along the first path. In fact, the excess slag separated from the product by the inner gate of the hopper leaves the hopper at a different time than the product, rather than along a different path.

[0044] Additional machinery or components may be used to collect the slag that travels along the first path. For example, a vacuum pump may be configured to collect the separated slag as it is discharged from the hopper along the first path. Additionally or alternatively, the first path may traverse or pass over a filter, grid, grille, lattice, or net that includes a plurality of holes (e.g., in a regular or irregular array). The holes may be sized to allow the slag to pass, but not the product. Thus, when the product and slag pass over the filter, the product will continue to travel on the first path, while the slag may be separated and diverted along a path different from that of the product.

[0045] In a further embodiment, the device can be switched between two different modes (i.e., configured to be switched), wherein in a first mode, the outer gate and the inner gate can move together, and in a second mode, the outer gate and the inner gate can move independently. Thus, the hopper can be configured to discharge excess slag along a first path or a second path.

[0046] In a preferred embodiment, the inner gate includes one or more holes, each hole being sized to allow the passage of slag but prevent the passage of product. Thus, slag can pass through the hole (i.e., completely through the cavity or perforation of the inner gate), while the product cannot. Thus, the product is retained by the inner gate, while the slag is not. Additionally or alternatively, the hopper can be configured such that a gap or hole is defined between the inner gate and a fixed wall of the hopper, wherein the slag can pass through the gap or hole but the product cannot pass through.

[0047] Should be understood that a plurality of holes can be arranged in a variety of layouts across the surface of the inner gate.In addition, these holes can adopt various sizes and shapes.

[0048] Preferably, at least one dimension of the hole is smaller than the smallest dimension of the product for which the hopper is intended. Thus, the product may not pass through the hole. Also preferably, the size of the hole is larger than the largest dimension of the slag so that the slag can pass through the hole.

[0049] For example, the smallest dimension of each hole in the plane of the inner gate is preferably in the range of 0.1 cm to 1 cm, and preferably in the range of 0.1 cm to 0.5 cm. The term "smallest dimension" is understood to mean the smallest dimension of the hole in the plane of the inner gate. For example, if the hole is circular, its smallest dimension is the diameter of the hole. However, if the hole is elongated, its smallest dimension is its width perpendicular to its extension direction.

[0050] The dimensions discussed above are suitable for a wide range of applications and are particularly well suited for use in the food packaging industry. For example, an inner gate including an aperture having at least one size in the range of from 1 cm to 0.1 cm is well suited for separating bulk sugar from sugary candies, excess seasoning from potato chips and French fries, and excess marinade from marinated meat products. However, apertures having alternative sizes may be selected for alternative mixtures of product and scraps.

[0051] In a preferred embodiment, the inner gate may comprise a filter, a grid, a grille, a lattice, a gauze, a sieve or a net. Thus, the inner gate may comprise a plurality of holes arranged in a regular or irregular array.

[0052] In contrast, the outer gate may be formed from a continuous sheet of material. For example, the outer gate may be formed from a sheet or plate of metal with no holes or cavities extending through it. Thus, the outer gate will prevent both product and slag from passing through. Having said that, in alternative embodiments, the outer gate may include a small number of holes or holes of a size small enough that neither slag nor product can pass through.

[0053] The inner gate, outer gate and / or any fixed wall of the hopper may be formed of metal such as stainless steel, steel and aluminum, alloys, plastics or composite materials (although any other suitable material may be used). In a preferred embodiment, the gate and walls of the hopper may be constructed of folded stainless steel (but this is not required).

[0054] In a preferred embodiment, the surface roughness Ra (i.e., the average deviation of the surface) of the inner gate, outer gate and / or any fixed wall of the hopper may be less than 10 μm, more preferably less than 5 μm, more preferably less than 2 μm. In a particularly preferred embodiment, the surface roughness may be less than 1.6 μm. Materials with low surface roughness may prevent products and / or slag from sticking or adhering to the hopper. Additionally or alternatively, the inner gate, outer gate and / or any fixed wall of the hopper may be provided with a surface relief configured to reduce friction between the hopper and the product and / or slag, thereby preventing the product and / or slag from adhering to the surface of the hopper.

[0055] In a particularly preferred embodiment, the hopper comprises two opposing inner gates and / or two opposing outer gates. By opposing gates, we understand that when each opposing gate is in its respective closed position, the free ends (e.g., lower ends) of each opposing gate will intersect or abut, and when each opposing gate is in its respective open position, the free ends will be laterally spaced apart, defining an opening through which the product can leave the hopper (e.g., under the action of gravity). In other words, the two opposing inner gates are configured to close together when each is in its respective closed position, and similarly, the two opposing outer gates are configured to close together when each is in its respective closed position. In effect, the hopper is closed by two consecutive pairs of "double doors" in the form of inner and outer gates.

[0056] Therefore, in a preferred embodiment: the inner gate discussed above can be the first inner gate, and the outer gate discussed above can be the first outer gate; and wherein the hopper further comprises: a second inner gate, the second inner gate being configured to prevent the passage of product but allow the passage of debris, and wherein the first inner gate and the second inner gate are relative; and a second outer gate, the second outer gate being configured to prevent the passage of product and prevent the passage of debris, and wherein the first outer gate and the second outer gate are relative; the second inner gate and the second outer gate can be moved between respective open and closed positions; the hopper is configured such that: when the first inner gate and the second inner gate and the first outer gate and the second outer gate are in their respective closed positions and the mixture is introduced into the hopper, the product is retained by the first inner gate and the second inner gate, while the debris passes through the first inner gate and the second inner gate and is retained by the first outer gate and the second outer gate; when the first inner gate and the second inner gate and the first outer gate and the second outer gate are in their respective open positions, the product can leave the hopper along the first path.

[0057] The device can be configured to move the first inner gate and the second inner gate substantially simultaneously (i.e., in tandem or simultaneously) between their open and closed positions. Similarly, the device can be configured to move the first outer gate and the second outer gate substantially simultaneously between their open and closed positions. Thus, the movement of the first inner gate and the second inner gate can be mirror images, and the movement of the first outer gate and the second outer gate can be mirror images.

[0058] Each of the first inner gate and the second inner gate may include any of the features of the inner gate discussed above. In a preferred embodiment, the first inner gate and the second inner gate may be substantially identical, mirrored about the centerline of the hopper (although this is not required). Similarly, each of the first outer gate and the second outer gate may include any of the features of the outer gate discussed above, and the first outer gate and the second outer gate may be substantially identical, mirrored about the centerline of the hopper (although this is again not required).

[0059] Hoppers with opposed gates (so called "double doors") are particularly well suited for use with sticky products and / or crumbs (e.g., marinated meat or sticky candies). In these embodiments, the product and / or crumbs can adhere or stick to the inside of the hopper. The opposed gates, especially opposed gates that open and close substantially simultaneously, exert a significant force on the contents of the hopper to prevent the product and / or crumbs from sticking to the inside of the hopper. Thus, hoppers with these "double doors" can more consistently and reliably discharge sticky products.

[0060] In some embodiments, the hopper may be a weigh hopper, a tank hopper, a boost hopper, a timing hopper, an output hopper, or a discharge hopper. Such hoppers are commonly used in computer controlled weigh scales and other product handling devices. Thus, product handling devices can benefit from the advantages provided by reduced scrap levels in their product lines.

[0061] According to another aspect of the invention, there is provided a system comprising one or more hoppers according to the foregoing aspects of the invention. Each of these hoppers may include any of the preferred or optional features discussed above.

[0062] The system may include a vacuum pump connected to a first hopper in the one or more hoppers, the vacuum pump being configured to collect debris that exits the first hopper along the second path. Thus, the vacuum pump may provide a suction force to remove or pull debris from the first hopper. In some cases, the collected debris may be reintroduced into the system upstream of the first hopper to reduce waste. The vacuum pump may be connected to multiple hoppers within the one or more hoppers and collect debris from the multiple hoppers. Alternatively, each hopper may be connected to a different vacuum pump.

[0063] Additionally or alternatively, the system may include one or more vacuum pumps to collect the cuttings that exit the hopper along their first path (eg, by opening an outer gate of the first hopper while the inner gate remains closed).

[0064] The system may also include a tube configured to be connected to a first hopper of the one or more hoppers, wherein the second path extends through the tube. Thus, the slag can be discharged or discharged from the hopper through the tube (although this is not required). The advantages of these tubes are discussed above, and these tubes can be provided as rigid or flexible tubes to meet any cleaning or maintenance requirements of the system. Preferably, each hopper can be connected to a corresponding tube.

[0065] Preferably, the system includes a weighing system, such as a combination weigher, a multi-head weigher, a screw feed weigher, a cut gate weigher, a linear weigher or a hybrid weigher. When used with the hoppers discussed above, these machines can accurately and quickly output product portions of predetermined volume or weight, wherein these portions contain reduced levels of slag. The weighing system may include a plurality of hoppers, and preferably will include a plurality of hoppers according to the first aspect of the invention. For example, the weigher may include a plurality of the hoppers discussed above, which are arranged circumferentially around a feeding device (e.g., a dispersed feeder) and fed by the feeding device.

[0066] In a preferred embodiment, the system comprises a packaging machine, wherein preferably the packaging machine is a bag making machine, a tray sealing machine, a cartoning machine or a thermoforming machine. Thus, the product stream with a reduced proportion of crumbs discharged from one or more hoppers can be fed into a suitable container in the packaging machine. Thus, the system can output or produce packaged products with reduced crumbs output by the system.

[0067] As mentioned above, it is particularly advantageous to provide a hopper just upstream of the packaging machine in order to remove the debris as a final step before the product is packaged. Thus, preferably, the hopper is arranged to distribute the product along a first path into the packages of the packaging machine. As mentioned above, the product may drop directly into the packages of the packaging machine and / or the first path may pass the product through one or more funnels or chutes before the product enters the package.

[0068] Other benefits of the systems according to the invention are discussed above with reference to the first aspect of the invention.These systems may include any of the preferred or optional features discussed above.

[0069] According to another aspect of the present invention, there is provided a method for separating slag from a mixture of product and slag, the method comprising:

[0070] (a) introducing a mixture of product and slag into a hopper, the hopper comprising: an inner gate configured to prevent the product from passing through but allow the slag to pass through; an outer gate configured to prevent the product from passing through and the slag to pass through, the inner gate and the outer gate being movable between respective open and closed positions;

[0071] wherein the mixture is introduced into the hopper when the inner gate and the outer gate are in their respective closed positions such that the product is retained by the inner gate and the slag is retained by the outer gate;

[0072] (b) collecting debris retained by the outer gate; and

[0073] (c) moving the inner gate and the outer gate into their respective open positions so that the product retained by the inner gate exits the hopper via the first path.

[0074] This method allows the removal of slag from the product flow. The contents of the hopper discharged in step (c) by opening the inner and outer gates have a reduced level of slag compared to the mixture introduced into the hopper in step (a). Therefore, the method is very reliable and provides a product of improved quality. Other advantages of this method are discussed above with reference to the first aspect of the invention.

[0075] Preferably, collecting the debris retained by the outer gate includes: allowing the debris retained by the outer gate to leave the hopper through a second path, the second path being different from the first path; or, moving the outer gate to its respective open position while the inner gate remains in its respective closed position, so that the debris retained by the outer gate leaves the hopper via the first path.

[0076] Thus, in the first case, excess crumbs are separated from the product by an inner gate within the hopper and directed out of the hopper along a different path than the product (e.g., so that the excess crumbs can be collected and reused). While in the second case, excess crumbs separated by the inner gate are directed out of the hopper along the same path as the product. Compared to the previous option, the excess crumbs and product are discharged at different times, and the excess crumbs and product are separated in time rather than in space (as in the previous method, the crumbs and product are discharged from the hopper along different paths). In other embodiments, the crumbs separated by the inner gate and retained by the outer gate can be manually removed from the hopper (i.e., collected).

[0077] It should be understood that in some embodiments, a single device or system can be configured to perform one or both of these process steps. For example, a device or system can switch between two different modes (i.e., the device or system can be controlled to switch), where in a first mode, the device or system can implement a first method; and in a second mode, the device or system implements a second method. However, this is not required.

[0078] In a preferred embodiment, collecting the slag retained by the outer gate includes operating a vacuum pump to collect the slag from the hopper. The vacuum pump can be operated continuously or periodically. For example, the vacuum pump can be operated simultaneously with step (b) of draining excess slag from the hopper in each method. Depending on the configuration of the system, the vacuum pump can collect slag that leaves the hopper along the first path or the second path.

[0079] In a further preferred embodiment, the method may further include:

[0080] (d) moving the inner and outer gates to their respective closed positions;

[0081] Wherein steps (a) to (d) are performed iteratively, and wherein preferably each iteration of step (c) occurs at least 100 ms after the previous iteration of step (d), preferably at least 200 ms after the previous iteration of step (d), more preferably at least 300 ms after the previous iteration of step (d), even more preferably at least 400 ms after the previous iteration of step (d). Such a delay may provide time for separating the slag in the hopper before the product is discharged. A larger delay will ensure that the final product has a reduced level of slag and is of higher quality. However, in the case where the hopper dispenses the product into packages of a packaging machine, it is desirable to ensure that each iteration of step (c) occurs at most 1000 ms after the previous iteration of step (d), preferably at most 800 ms after the previous iteration of step (d), more preferably at most 600 ms after the previous iteration of step (d), and most preferably at most 500 ms after the previous iteration of step (d). Reducing the delay between each iteration helps maintain the overall throughput of the system, which is particularly important where the hopper is a bottleneck for dispensing packages into the packaging machine. The preferred range is between 200ms and 800ms, preferably between 400ms and 600ms, for each iteration of step (c) occurring after the previous iteration of step (d).

[0082] In an alternative embodiment, the hopper may form part of a weigher, such as a computer combined weigher (CCW). In such an embodiment, a longer delay may be preferred to ensure a more accurate measurement of the weight of the product. In such an embodiment, multiple hoppers in the weigher may weigh simultaneously and selectively dispense an amount of product to form batches of predetermined weights, so a longer delay will have less impact on the overall throughput of the system and may therefore be preferred to improve slag removal. In such an embodiment, it may be preferred that each iteration of step (c) occurs at least 400ms after the previous iteration of step (d), preferably at least 600ms after the previous iteration of step (d), more preferably at least 800ms after the previous iteration of step (d), and even more preferably at least 1000ms after the previous iteration of step (d). However, the delay time may be defined to provide a balance between settling time and the throughput of the device.

[0083] The inner and outer gates may be returned to their respective closed positions substantially simultaneously or simultaneously (but this is not required).

[0084] As mentioned above, the hopper may be integrated into a weighing system, and in this case, additionally or alternatively, the method further comprises the following steps after step (c):

[0085] (i) obtaining a time series of weight measurements of the contents of the hopper;

[0086] (ii) determining, based on weight measurements, that the weight of the contents of the hopper has stabilized;

[0087] Therein step c) is only performed once said determination has been made.

[0088] Thus, the weight of the contents of the hopper is monitored and the contents of the hopper are discharged only when the measurement is stable - that is, when the weight of the contents of the hopper is accurately known. For example, the weight measurement can be performed continuously or periodically (e.g. every 10 ms). In a further embodiment, the weight measurement can be performed at least every 0.5 s, preferably at least every 0.25 s, even more preferably at least every 0.1 s, even more preferably at least every 0.05 s. If two or more consecutive measurements have the same value (e.g. three consecutive measurements), and / or if the difference or range between two or more consecutive measurements is less than a predetermined value (e.g. less than 1 g, more preferably less than 0.5 g, even more preferably less than 0.15 g), it can be determined that the weight of the contents of a particular hopper has stabilized.

[0089] The method may also include the step of transferring the product exiting the hopper via the first path into a packaged article and then sealing the packaged article. This step may be performed by a bag making machine, a tray sealing machine, a carton machine, or a thermoforming machine. The packaged article filled during this step may be a bag, a tray, or a carton (although other packaged articles may also be suitable). The final packaged article may have a reduced level of debris and have improved quality.

[0090] In a preferred embodiment, the above method can be performed using any of the devices or systems discussed above with reference to the previous aspects of the present invention. In addition, further optional and preferred features of the method have been discussed above with reference to the previous aspects of the present invention (i.e., the devices and systems discussed above). Similarly, many other benefits of the method that can be achieved using these methods are also described in detail above with respect to the devices and systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1a , Figure 1b , Figure 1c A schematic cross section of a device according to the invention is shown; the figure shows the sequential arrangement of the device when the device carries out the method according to the invention.

[0092] Figure 2a and Figure 2b A schematic cross section of a further device according to the invention is shown.

[0093] Figure 3 A schematic cross section of a further device according to the invention is shown.

[0094] Figure 4a and Figure 4b Showing perspective views of another device according to the present invention in a closed arrangement and an open arrangement, respectively; Figure 4c shows a cross section through the device in its closed arrangement; Figure 4d showing a side view of the device in its open arrangement; Figure 4e Another cross section through the device in its closed arrangement is shown.

[0095] Figure 5 Schematically shows Figures 4a to 4d The preferred position of the device in the system according to the invention. DETAILED DESCRIPTION

[0096] Figure 1a , Figure 1b and Figure 1c A hopper 10 is shown which is suitable for removing shavings S from a mixture of product P and shavings S. As shown, shavings S are solid particles (e.g. excess sugar) of a size significantly smaller than product P. In more detail, Figure 1a to Figure 1c The size of the cuttings S shown in FIG. 1 is approximately an order of magnitude smaller (ie, 10 times smaller) than the size of the product P. However, the hopper 10 is equally suitable for use with mixtures containing liquid cuttings or solid cuttings having alternative sizes relative to the product.

[0097] The hopper 10 includes an upper opening 11 through which the product P and the slag S can be introduced into the hopper 10 (eg Figure 1a The hopper 10 includes two gates: an inner gate 12 and an outer gate 14.

[0098] The inner gate 12 includes a plurality of holes 13 extending through the inner gate 12 (i.e., between two opposite sides of the inner gate). The holes 13 are sized so that the debris S can pass through the holes 13 (and thus through the inner gate 12), but the products P cannot pass through. Therefore, the inner gate 12 is configured to filter the debris S or separate the debris S from the products P. The size of each hole 13 in the plane of the inner gate 12 is larger than the largest size of the debris S and smaller than the smallest size of the products P.

[0099] In contrast, the outer gate 14 is continuous and formed without any holes. Neither the product P nor the slag S can pass through the solid outer gate 14. The outer gate 14 is positioned lower than the inner gate 12, which is positioned within the hopper 10 (i.e., within the interior volume of the hopper 10 defined by the side walls 16a, 16b and the outer gate 14), so that the slag passing through the inner gate 12 will be retained by the outer gate 14.

[0100] The inner gate 12 is connected to the first side wall 16a of the hopper 10 by a hinge 12a about which the inner gate 12 can rotate. The inner gate 12 can move between two positions: Figure 1a and Figure 1b The closed position shown and Figure 1c The open position shown, in which the inner gate 12 extends between the side walls 16a, 16b of the hopper in the closed position; in the open position, the inner gate 12 is suspended from its respective hinge 12a so that a gap exists between the distal or free end of the inner gate 12 and the second side wall 16b of the hopper 10.

[0101] Similarly, the outer gate 14 is connected to the first side wall 16a of the hopper 10 by a hinge 14a, about which the outer gate 14 can rotate. Like the inner gate 12, the outer gate 14 can be placed in two positions: Figure 1a and Figure 1b The closed position shown and Figure 1c The outer gate 14 is in its open position (as shown), in which the outer gate 14 extends between the side walls 16a, 16b of the hopper to close the lower opening 19 of the hopper 10; in which the outer gate 14 is suspended from its hinge 14a so that there is a gap between the distal end or free end of the outer gate 14 and the second side wall 16b of the hopper 10. Figure 1c As shown), the lower opening 19 of the hopper 10 is opened so that the contents of the hopper 10 can leave the hopper 10.

[0102] Now refer to Figure 1a , Figure 1b and Figure 1c A method of separating scraps S from a mixture of product P and scraps S is discussed. The figures illustrate sequential steps performed using the hopper 10 .

[0103] First, a mixture of product P and slag S is introduced into the hopper 10, while the inner gate 12 and the outer gate 14 are in their respective closed positions (such as Figure 1a shown).

[0104] Having entered the hopper 10, the product P and the scraps S encounter an inner gate 12. The scraps S can pass through the holes 13 in the inner gate 12, but the product P cannot. Thus, the product P is retained by the inner gate 12, while a proportion (preferably substantially all) of the scraps S contained in the hopper 10 travels through the inner gate 12. The scraps S that pass through the inner gate 12 fall to the lower outer gate 14. Thus, the scraps S that travel through the inner gate 12 are held or captured by the outer gate 14 below. The resulting arrangement is Figure 1b Shown in.

[0105] from Figure 1bIt will be seen that a small amount of slag S may be retained with the product P retained by the inner gate 12. In many cases, it will be more preferred to remove a large proportion of the slag S (e.g., at least 75% of the slag or at least 90% of the slag) from the mixture of product P and slag S. However, in practice, it may be difficult and / or unnecessary to separate all of the slag S from the product P.

[0106] It will be appreciated that the proportion of slag S removed from the mixture using the hopper is controlled by, for example, varying the length of time the mixture spends in the hopper 10 (i.e., the residence time of the product P); and the size and distribution of the holes in the inner gate 12; and the dimensions of the hopper 10. These parameters can be varied to vary the proportion of slag S removed from a given mixture of slag S and product P.

[0107] Once the slag S has been separated from the product P by the inner gate 12, the separated slag S is allowed to leave the hopper 10. The slag S may be collected automatically or manually and may be reintroduced into the production line upstream of the hopper 10 to reduce waste. For example, the separated slag S retained by the outer gate 14 may be removed from the hopper 10 by operating a vacuum pump (not shown) and / or by opening the outer gate 14 while keeping the inner gate 12 closed to discharge only the separated slag S through the lower opening 19 of the hopper (although other techniques may also be used).

[0108] Subsequently, the product P retained by the inner gate 12 can be discharged or distributed from the hopper 10, such as Figure 1c The remaining contents of the hopper 10 are released by opening the inner gate 12 and the outer gate 14 simultaneously, ie by moving the inner gate and the outer gate to their respective open positions. Figure 1c This step is illustrated showing the product P passing through the lower opening 19 of the hopper 10 .

[0109] Thus, the product P (and any remaining scraps S) leaves the hopper 10 along a first path extending through the lower opening 19 of the hopper 10. Figure 1c The product mixture discharged from the hopper 10 has significantly less slag S than the product mixture introduced into the Figure 1a The product mixture is in the hopper 10.

[0110] The inner gate 12 and the outer gate 14 can be returned to their respective closed positions (such as Figure 1a ) and repeating the process by refilling the hopper 10 with a fresh mixture of product P and slag S.

[0111] A delay may be provided between closing the inner gate 12 and the outer gate 14 and reopening the inner gate 12 and the outer gate 14. The delay may allow the mixture of product P and slag S to enter the hopper 10 and enable the slag S to be separated and collected from the hopper 10. Additionally, the delay may allow the remaining contents of the hopper 10 to settle and the weight of the contents of the hopper to stabilize. The delay may be, for example, 400 ms or 800 ms.

[0112] Additionally or alternatively, the weight of the contents of the hopper 10 may be periodically or continuously monitored so that once the weight of the hopper 10 has stabilized (indicating that the contents of the hopper 10 have sunk and excess slag S has been removed), but not before, the gates 12, 14 of the hopper 10 are opened. For example, the weight of the contents of the hopper 10 may be measured periodically, for example every 10 ms. If three consecutive measurements have the same value, or are within a predetermined range, for example 0.15 g, it may be determined that the weight of the contents of the hopper 10 has stabilized.

[0113] The product P discharged from the hopper 10 may then be transferred or fed into a packaged article (eg, a bag, a tray or a carton). The method may further comprise the step of sealing the packaged article (eg, using a bag making machine, a tray sealing machine, a carton machine or a thermoforming machine).

[0114] Figure 2a and Figure 2b Shows Figure 1a , Figure 1b and Figure 1c This modified hopper 10 is again suitable for separating slag S from product P using the method described above and is used in conjunction with Figure 1a , Figure 1b and Figure 1c The illustrated hoppers 10 share many features and advantages. Corresponding features of the two hoppers 10, 10' are indicated by reference numerals with a prime symbol.

[0115] Figure 2a and Figure 2b The hopper 10' comprises two side walls 16a', 16b' defining an upper opening 11' therebetween through which products and slag can be introduced into the hopper 10'. The hopper 10' comprises an inner gate 12' and an outer gate 14', the outer gate 14' being located below the inner gate 12' (as shown).

[0116] The inner gate 12' includes a plurality of holes 13', which are sized so that the slag, but not the product, can pass through the inner gate 12'. Thus, the inner gate 12' can filter out the slag from the mixture of product and slag. In contrast, the outer gate 14' is continuous, with no gaps or holes formed, so that the slag does not pass through the outer gate 14'.

[0117] The inner gate 12' and the outer gate 14' can rotate about respective hinges 12a', 14a' connected to the first side wall 16a' of the hopper 10'. Thus, the inner gate 12' and the outer gate 14' can move between respective open and closed positions.

[0118] Figure 2b The inner gate 12' and the outer gate 14' are shown in their respective open positions. In this arrangement, a lower opening 19' of the hopper 10' is defined. The contents of the hopper 10' can be moved along a first path extending through the lower opening 19' (as shown by arrow R). 1 Instructions) leave the hopper 10'.

[0119] Different from the above-mentioned embodiments, Figure 2a and Figure 2b The hopper 10' includes a slag collecting duct 17 disposed in the second side wall 16b' of the hopper 10'. The slag collecting duct 17 can be used to collect slag that has passed through the inner gate 12' and has been retained by the outer gate 14'.

[0120] Therefore, the slag can follow a second path (indicated by arrow R) different from the first path. 2 The second path (indicated) leaves the hopper 10' and extends through the slag collection pipe 17. As can be seen from the figure, the second path is laterally offset and inclined from the first path.

[0121] The hopper 10' is configured so that the slag collection duct 17 is located at the lower end of the second wall 16b'. In addition, when the outer gate 14' is in the closed position (such as Figure 2a As shown in FIG. 1 , the outer gate 14 ′ is angled relative to the horizontal plane and is inclined toward the slag collection pipe 17. Therefore, the slag reaching the closed outer gate 14 ′ can flow toward the slag collection pipe 17 and flow out of the hopper 10 ′ along the second path.

[0122] A vacuum pump (not shown) may be connected to the debris collection conduit 17 (eg, via a flexible tube) to pull debris from the hopper 10'. However, in alternative embodiments, the debris may follow the second path R under gravity and without assistance. 2 It flows downward and passes through the slag collection pipe 17.

[0123] Figure 3 Another hopper 20 is shown that includes a "double door" arrangement. This hopper 20 is well suited for use with sticky products that may adhere to the side walls and gate of a "single door" hopper (such as the hoppers 10, 10' shown in Figures 1 and 2).

[0124] The hopper 20 includes an upper opening 21 defined between a pair of side walls 26a, 26b. A pair of opposing inner gates 22 and a pair of opposing outer gates 24 are disposed between the side walls (each at Figure 3 Each inner gate 22 includes a plurality of holes 23 through which slag but not product can pass. Each inner gate 22 and each outer gate 24 can be rotated about their respective hinges 22a, 24a between a respective closed position and a respective open position.

[0125] exist Figure 3 The inner gate 22 and the outer gate 24 are shown in their respective closed positions. As will be seen, the inner gates 22 protrude from their respective side walls 26a, 26b so that the free ends of the inner gates 22 intersect at the center of the hopper 20. Similarly, the outer gates 24 protrude from the side walls 26a, 26b of the hopper 20 so that their free ends intersect at the center of the hopper 20.

[0126] In this arrangement, the shavings can be filtered out of the mixture of product and shavings introduced into the hopper 20. The shavings introduced into the interior volume of the hopper 20 can pass through the holes 23 in the inner gate 22, while the product cannot. The separated shavings will then be retained by the outer gate 24 below, which is a continuous sheet without holes.

[0127] The separated slag can then be removed from the hopper 20 and collected. For example, the separated slag can be removed from the hopper 20 manually by simply opening the outer gate 24 or by operating a vacuum pump (not shown). In other embodiments, a slag collection pipe or hole can be provided in the wall of the hopper 20, through which the slag can leave the hopper 20.

[0128] Subsequently, by moving the inner gate 22 and the outer gate 24 to their respective open positions, the product remaining in the hopper 20 can be discharged from the hopper 20. Thus, the hopper 20 can be used to discharge a product mixture with reduced fines, i.e., a mixture from which fines have been removed.

[0129] It should be understood that FIG. 2 and Figure 3 The hoppers 10', 20 shown in FIG. 1 may include any preferred or optional features discussed with respect to the hopper 10 shown in FIG. 1 (and vice versa). Figure 3 The hoppers 10 ′, 20 may perform process steps corresponding to those described with respect to the hopper 10 of FIG. 1 .

[0130] Figures 4a to 4e Another hopper 30 with a "double door" is shown, which is suitable for separating the scraps from the mixture of product and scraps.

[0131] The hopper 30 includes a pair of opposed outer gates 34. Each outer gate 34 can be in a respective closed position (in Figure 4a , Figure 4c and Figure 4e ) and their respective open positions (shown in Figure 4b and Figure 4d When each outer gate 34 is in its respective closed position, the free ends of the outer gates 34 intersect or abut at the center of the hopper 30, thereby closing the lower opening 39 of the hopper 30. However, when each outer gate 34 is in its open position, the outer gates 34 are laterally offset or spaced apart, and the lower opening 39 extends between the outer gates 34.

[0132] A corresponding lever arm 34b is used to control the rotation of each outer gate 34. Each lever arm 34b is fixed to the corresponding outer gate 34 and is rotatably coupled to the side wall 36 of the hopper 30 by a hinge (not shown) extending through a hole 34c in the lever arm 34b and the side wall 36 of the hopper 30.

[0133] The hopper 30 also includes a pair of opposing inner gates 32. Each inner gate 32 is fixedly connected to a corresponding outer gate 34 (such as Figure 4c Each inner gate 32 extends parallel to the outer gate 34 to which it is attached (although this is not required). The connection between the corresponding inner gate 32 and outer gate 34 can be permanent (e.g., the gates 32, 34 can be welded or bonded together using an adhesive) or non-permanent (e.g., using threaded fasteners such as screws).

[0134] Since the inner gates 32 are fixed relative to the outer gates 34, each inner gate 32 will rotate with the outer gates 34 to which they are attached. Therefore, each inner gate 32 can be moved between a respective open position and a respective closed position by moving the corresponding outer gate 34 between its respective open position and closed position.

[0135] When the inner gates 32 are in their respective closed positions, the inner gates 32 intersect at the center of the hopper 34. Each inner gate 32 includes an array of holes 33 extending through the inner gate 32. The holes 33 are sized so that relatively large products cannot pass through the inner gates 32, while relatively small or liquid debris can travel through the inner gates 32. Thus, the inner gates 32 can act as filters to separate product from debris when each inner gate 32 is in its respective closed position.

[0136] As shown, each inner gate 32 includes a repeating array of oblong apertures 32. However, it should be appreciated that apertures having a variety of sizes and arrangements may be selected for use in the hopper 30, depending upon the mixture of product and cuttings in question.

[0137] When the inner gate 32 and the outer gate 34 are placed in their closed positions (such as Figure 4c As shown, it is along Figure 4e When a mixture of product and slag is introduced into the hopper 30, the product will be retained by the inner gate 32, while the slag can pass through the inner gate 32 and fall to the outer gate 34 below.

[0138] Each outer gate 34 also includes a slot 38 (most easily located in Figure 4c ). The trough 38 is an open passage or conduit that can receive slag that has passed through the overlapping inner gate 32. In particular, the hopper 30 is configured so that when the inner gate 32 and the outer gate 34 are in their respective closed positions, slag that has passed through the inner gate 32 may fall to the outer gate 34 and accumulate in the trough 38.

[0139] When the outer gates 34 are in their respective closed positions, the outer gates 34 are inclined toward their respective slots 38. In fact, when each outer gate 34 is in its closed position, the outer gate 34 is inclined downward from an end proximate to the respective hinge and lever arm 34b toward a free end including the slot 38. Since each outer gate 34 is inclined toward its respective slot 38 when the outer gates 34 are in their respective closed positions, debris that passes through the inner gate 32 and then reaches the outer gate 34 can fall or flow into the slot 38 along the surface of the outer gate 34 (e.g., under the action of gravity).

[0140] The bottom 38a of each trough 38 is inclined relative to the horizontal plane so that the depth of the trough 38 increases along the length of the trough 38. Therefore, debris accumulated in the trough 38 can flow or travel laterally along the bottom 38a of the trough 38 (e.g., under the action of gravity).

[0141] The hopper 30 also includes a debris collection duct 37 connected to each outer gate 34 at its lower edge. More specifically, each debris collection duct 37 is connected to the lower end of the corresponding slot 38. Therefore, the debris that passes through the inner gate 32 and falls to the outer gate 34 will flow or be discharged into the slot 38 along the inclined surface of the outer gate 34, and will then flow or be discharged to the debris collection duct along the inclined bottom 38a of each slot 38. Therefore, each slot 38 and the corresponding debris collection duct 37 are in communication, and the debris can leave the hopper 30 along a path (i.e., a second path) extending from each slot through the corresponding debris collection duct 37. This path is offset and inclined relative to the substantially vertical path (i.e., the first path) that the contents of the hopper 30 will take to pass through the lower opening 39 of the hopper when the inner gate 32 and the outer gate 34 are moved to their respective open positions.

[0142] Exit of the hopper 30 through the chip collection conduit 37 may occur under gravity by vibrating the hopper and / or the chip collection conduit 37 , and / or by connecting a vacuum pump (not shown) to apply suction to the chip collection conduit 37 .

[0143] The slag connection pipe 37 can be connected to a flexible pipe (not shown), although a rigid pipe can also be used as described above. The flexible pipe can adapt to the position changes of the slag removal pipe 37 when the outer gate 34 of the hopper 30 is opened and closed. For example, a vacuum pump can be connected to the slag connection pipe 37 via a flexible pipe. However, this is not required, and in other embodiments, the slag removal pipe 37 itself can be formed of a flexible material and / or can be directly connected to a vacuum pump or container. In these cases, the slag can continue to travel along the second path continued by the flexible pipe.

[0144] It should be understood that Figures 4a to 4e In the illustrated embodiment, when the outer gates 34 are in their respective closed positions and their respective open positions, the slag can flow from the trough 38 into the slag collection conduit 37 and thus out of the hopper. Thus, excess slag can continue to be discharged from the hopper 30 without delaying the hopper 30 from discharging its remaining contents.

[0145] Thus, once the mixture of product and slag is introduced into the hopper 30, the slag will be separated from the product through the inner gate 32. The separated slag will accumulate in the groove 38 of the outer gate and will leave the hopper for collection through the slag collection pipe 37. Subsequently, by opening the inner gate 32 and the outer gate 34, the remaining contents of the hopper can be discharged through the lower opening 39 of the hopper 30.

[0146] The contents of the hopper 30 may be discharged only when the contents have had a chance to settle. For example, the inner and outer gates 32, 34 of the hopper 30 may be opened only after a predetermined delay (e.g., 400 ms, 800 ms, or 1000 ms) or when the weight of the contents of the hopper has stabilized (e.g., when the weight measurement from the hopper is constant or falls within a predetermined tolerance range).

[0147] The discharged product with reduced scrap level distributed by the hopper 30 can then be packaged using packaging equipment and / or continue to be processed and / or modified by subsequent machines. Due to the reduced scrap level, subsequent packaging and product processing operations will be more reliable and of higher quality.

[0148] Any of the hoppers discussed above can be installed in a wider product handling system.

[0149] For example, a hopper may be provided as part of a weighing system and used to accurately discharge a known amount of product with a reduced level of crumbs. The product handling system may also include packaging equipment to package the discharged product. Alternatively, the product may continue along the production line and be further modified by subsequent machines. Due to the reduced level of crumbs dispensed by the hopper discussed above, subsequent packaging and product handling operations may be more reliable and provide higher quality packaged items.

[0150] Now refer to Figure 5 Describes the method of installing in the system according to the present invention Figures 4a to 4d A preferred embodiment of the hopper.

[0151] Figure 5 The hopper 30 described above is schematically shown installed in a system 100 that forms batches of product having predetermined weights and provides these fixed weight batches to a packaging machine.

[0152] The system 100 includes a combination weigher 200 located upstream of the hopper 30. An example of a suitable combination weigher is the RV series multi-head weigher sold by Ishida Europe Limited of 11 Kettles Wood Drive, Woodgate Business Park, Birmingham, B32 3DB.

[0153] Typically, a combination weighing device comprises a series of weighing hoppers 210 arranged in a circle around a central axis. Figure 5Only two of them are visible. Each weigh hopper is fed by a supplier (such as a product dispensing station) for receiving a certain amount of product. The weight of the product in each hopper is continuously monitored, and the combined weigher selects any two or more hoppers whose total weight meets the criteria related to the weight of a batch of products to be formed, and distributes the products from those hoppers to gather the products into a single batch of products with the required weight. In this embodiment, the combined weigher 200 is shown as having a funnel 220 that surrounds all weigh hoppers 210 and is used to gather together the products distributed by any two or more weigh hoppers 210 and deposit the products in the slag separation hopper 30. It should be noted that each weigh hopper 210 can also form a slag separation hopper according to the present invention, although this is not required.

[0154] The crumb separation hopper 30 is thus provided with a mixture of product and crumbs, the weight of which meets the predetermined weight criteria for a batch of products. The crumbs are removed from the hopper 30 by the mechanism described above, which will generally have a negligible effect on the weight of the batch of products. In the event that a large amount of crumbs are removed at the hopper 30, this will generally be adjusted for in the combination weigher 200 by forming a batch that is overweight by a predetermined amount to compensate for the expected weight loss when the crumbs are removed. After a batch of products has been received, the hopper 30 then distributes the batch of products to the packaging machine 300 located downstream.

[0155] Figure 5 Only a portion of the packaging machine 300 is shown schematically. One example of a packaging machine suitable for use in the present system is the Astro Bagmaker sold by Ishida Europe Limited of 11 Kettles Wood Drive, Woodgate Business Park, Birmingham, B32 3DB.

[0156] The packaging machine 300 includes a former 310, which forms a supply film into a cylinder, and the cylinder of the film is sealed at intervals by a sealer (not shown) to form individual bags. The former 310 includes an inner forming tube 311 and an outer forming collar 312, which together form the supply film into a cylinder. The packaging machine also includes a funnel 320, which is connected to the upper opening of the inner forming tube 311 and feeds the product into the bag when the product is formed.

[0157] In the present system, the hopper 30, after having received the product from the weigher 200 and separated the crumbs, dispenses the batch of product along a first path, which in this case involves the product falling vertically under gravity into the hopper 320 of the packaging machine 300 when the hopper is opened, where it is received in the package, i.e., bag, as it is formed by the packaging machine. Once the lower seal of the bag has been made, the product will typically be dispensed by the hopper 30, and once the product is received in the bag, an upper seal will be made to seal the bag, which upper seal will thereby form the lower seal of the next bag so that the process can be repeated.

[0158] The time at which the hopper 30 opens to dispense the product into the packaging machine will typically be controlled by a system controller (not shown) that controls the scale 200, hopper 30, and packaging machine 300 of the system 100 together. Typically the system will run a complete cycle between 100 and 1000 ms, most typically about 500 ms. That is, multiple batches of product will be dispensed by the hopper 30 at regular intervals of about 500 ms to match the packaging production speed of the packaging machine 300.

[0159] Although the above system shows the hopper 30 integrated between the weigher 200 and the packaging machine 300, it should be understood that the hopper 30 is suitable for use anywhere along the production of the mixture of product and scraps. For example, as mentioned, the hopper can be integrated into the weigher 200, or can be integrated as part of the supply to the weigher 200.

Claims

1. A hopper for separating slag from a mixture of product and slag, the hopper comprising: an inner gate configured to prevent product from passing through but allow slag to pass through; as well as, an outer gate configured to prevent passage of product and to prevent passage of slag; The inner gate and the outer gate are movable between respective open and closed positions; The hopper is configured such that: When the inner gate and the outer gate are in their respective closed positions and the mixture is introduced into the hopper, product is retained by the inner gate and cuttings pass through the inner gate and are retained by the outer gate; When the outer gate and the inner gate are each in their respective open positions, product is able to exit the hopper along a first path; as well as A second path is provided for cuttings retained by the outer gates to exit the hopper when the outer gates are in their respective closed positions, the second path being different from the first path.

2. The hopper of claim 1, wherein the second path is inclined relative to the first path and / or laterally offset from the first path.

3. The hopper of claim 1 or 2, wherein the lower end of the outer gate includes a slot configured to receive slag when the outer gate is in its respective closed position.

4. The hopper of claim 3, configured such that when the outer gate is in its closed position, cuttings are able to travel along the trough and exit the hopper along the second path.

5. The hopper of claim 3, wherein the bottom of the trough is sloped so that cuttings can travel along the trough under the action of gravity.

6. The hopper of claim 1 or 2, wherein the hopper is configured to be connected to a vacuum pump, the vacuum pump being configured to collect slag that exits the hopper along the second path.

7. The hopper of claim 1 or 2, wherein the hopper is configured to be connected to a pipe, the second path extending through the pipe.

8. The hopper according to claim 7, wherein the hopper is connected to a vacuum pump via the tube.

9. The hopper according to claim 1 or 2, configured so that the inner gate is fixed relative to the outer gate.

10. The hopper of claim 1 or 2, wherein the hopper is configured to move the outer gate between the respective closed and open positions of the outer gates independently of the inner gate, such that when the outer gates are in their respective open positions and the inner gates are in their respective closed positions, debris can exit the hopper in a first direction while product is retained by the inner gate.

11. The hopper of claim 1 or 2, wherein the inner gate includes one or more apertures, each aperture sized to allow passage of cuttings but prevent passage of product.

12. The hopper of claim 11, wherein the smallest dimension of each aperture in the plane of the inner gate is in the range of 0.05 cm to 1 cm.

13. A hopper according to claim 12, wherein the smallest dimension of each aperture in the plane of the inner gate is in the range of 0.1 cm to 0.5 cm.

14. The hopper of claim 11, wherein the inner gate comprises a filter, mesh, grid, grille, gauze, screen and / or net.

15. The hopper according to claim 1 or 2, wherein the inner gate is a first inner gate and the outer gate is a first outer gate; and The hopper further comprises: a second inner gate configured to prevent the passage of products but allow the passage of slag, and wherein the first inner gate and the second inner gate are opposed; and, a second outer gate configured to prevent passage of product and to prevent passage of slag, and wherein the first outer gate and the second outer gate are opposed; The second inner gate and the second outer gate are movable between respective open and closed positions; The hopper is configured such that: when the first and second inner gates and the first and second outer gates are in their respective closed positions and the mixture is introduced into the hopper, product is retained by the first and second inner gates and cuttings pass through the first and second inner gates and are retained by the first and second outer gates; as well as When the first and second inner gates and the first and second outer gates are in their respective open positions, product can exit the hopper along a first path.

16. The hopper according to claim 1 or 2, wherein the hopper is a weigh hopper, a tank hopper, a booster hopper, a timing hopper, an output hopper or a discharge hopper.

17. A system comprising one or more hoppers according to any preceding claim.

18. The system of claim 17, comprising a vacuum pump connected to a first hopper of the one or more hoppers, the vacuum pump configured to collect slag that exits the first hopper along the second path.

19. The system of claim 17 or 18, further comprising a tube configured to be connected to a first hopper of the one or more hoppers, wherein the second path extends through the tube.

20. The system of claim 17 or 18, wherein the system comprises a weighing system.

21. The system of claim 20, wherein the weighing system is a combination weigher, a multi-head weigher, a screw feed weigher, a cutting gate weigher, a linear weigher, or a hybrid weigher.

22. The system according to claim 17 or 18, wherein: The system includes a packaging machine.

23. The system of claim 22, wherein the packaging machine is a bag making machine, a tray sealing machine, a carton making machine, or a thermoforming machine.

24. The system of claim 22, wherein the hopper is arranged to dispense product into packages for the packaging machine along the first path.

25. A method for separating slag from a mixture of product and slag, the method being performed using the apparatus according to any one of claims 1 to 16 or the system according to any one of claims 17 to 24, comprising: (a) introducing a mixture of product and slag into a hopper, the hopper comprising: an inner gate configured to prevent the product from passing through but allow the slag to pass through; and an outer gate configured to prevent the product from passing through and prevent the slag from passing through, the inner gate and the outer gate being movable between respective open and closed positions; wherein when the inner gate and the outer gate are in their respective closed positions, the mixture is introduced into the hopper such that product is retained by the inner gate and scraps are retained by the outer gate; (b) collecting debris retained by the outer gate; and (c) moving the inner gate and the outer gate to their respective open positions so that product retained by the inner gate exits the hopper via a first path.

26. The method of claim 25, wherein collecting debris retained by the outer gate comprises: allowing slag retained by the outer gate to exit the hopper via a second path, the second path being different from the first path; Alternatively, the outer gates are moved to their respective open positions while the inner gates remain in their respective closed positions, so that the cuttings retained by the outer gates exit the hopper via the first path.

27. The method of claim 25 or 26, wherein collecting the debris retained by the outer gate comprises operating a vacuum pump to collect debris from the hopper.

28. The method according to claim 25 or 26, further comprising: (d) moving the inner gate and the outer gate to their respective closed positions; Steps (a) to (d) are performed iteratively.

29. The method of claim 28, wherein each iteration of step (c) occurs at least 100 ms after a previous iteration of step (d).

30. The method of claim 28, wherein each iteration of step (c) occurs at least 200 ms after a previous iteration of step (d).

31. The method of claim 28, wherein each iteration of step (c) occurs at least 300 ms after a previous iteration of step (d).

32. The method of claim 28, wherein each iteration of step (c) occurs at least 400 ms after a previous iteration of step (d).

33. The method according to claim 25 or 26, further comprising the following steps after step (a): (i) obtaining a time series of weight measurements of the contents of the hopper; (ii) determining, based on weight measurements, that the weight of the contents of the hopper has stabilized; Wherein step (c) is performed only after said determination has been made.

34. The method of claim 25 or 26, further comprising the step of transferring product exiting the hopper via the first path into a packaged article and subsequently sealing the packaged article.

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