This patent application claims priority from Italian patent application no. 102020000012205 filed on May 25, 2020, the entire disclosure of which is incorporated herein by reference.
The present invention relates to a separation process and a plant for particulate material along a conveyor system of products, in particular flat products such as slabs.
Particulate matter is the set of solid and liquid particles found in the atmosphere. Particulate matter is classified according to particle size, i.e. the equivalent aerodynamic diameter of particles suspended in a gaseous fluid. For example, coarse particles with a diameter of 10 μm or less are classified as PM-10. Coarse particles PM-10 are generated, for example, by operations such as movement/crushing/cutting of solid materials. Fine particles with a diameter of 2.5 μm or less are classified as PM-2.5 and are generated, for example, by processes such as combustion.
In the manufacturing sector, like in the ceramics or woodworking sectors, production processes generate and disperse into the environment a significant quantity of particulate matter, in particular dust, which can have particle size varying from a few millimetres (e.g. chips) to a few microns (e.g. dust or fine ceramics).
The generation and dispersion of particulate matter in the work environment is highly damaging. In addition to fouling the work environment, particulate matter poses a threat to human health as it can be inhaled and, in the case of fine particles, absorbed.
In this regard, there are a number of regulations that set maximum permitted levels of particulate matter in an environment, such as a work environment.
In order to confine and limit the dispersion of particulate matter in the work environment, separation processes and plants are known.
Centralised separation processes and plants comprising a compressor (e.g., a fan) to which several vertical hoods are connected, each of which is positioned in a respective suction station, are known. The compressor is able to create a depression in correspondence of the suction mouth of each vertical hood. A vertical hood has the plane of the suction mouth vertically above the advancing plane of the products, i.e. the working plane. Disadvantageously, a vertical hood of known type does not allow to achieve a complete collection of the particulate matter, since it is arranged at a great distance from the advancing plane of the products.
Moreover, the upward suction depression has intrinsic limits of effectiveness, as it is necessary to overcome the force of gravity in the entire section between the product and the inlet of the suction pipe connected to the vertical hood.
A centralised separation plant of known type further comprises a single separation system in which the particulate matter is separated from the carrier gas flow.
If on the one hand the use of a single separation system simplifies the operations of collecting the particulate matter, disadvantageously this involves a significant increase in the length of the pipes and, in the case of use of separator cyclones, a reduction in the separation capacity. Consequently, known separation processes and plants are complex and expensive to manufacture and have large dimensions in the working area. In addition, known separation processes and plants are not very flexible, in other words they cannot be modified (for example the hoods cannot be modified) in a simple way.
Furthermore, separation plants called push-pull are known, these separation plants combine an air flow with a suction hood in turn connected to a separation system. The combination of a push air flow with a pull air flow allows, in fact, a significant increase in the capacity of removing the particulate matter. In these plants of known type, the air flow is transversal to the advancing direction of the products and the hood is not above the conveyor system of the products, i.e. the hood does not overhang the conveyor system. Although this solution allows achieving better performances than using vertical hoods only, some significant problems persist. In particular, the absence of overhang on the conveyor system by the hood causes a high dispersion of the particulate matter that is not collected by the hood once it is moved by the air flow. Furthermore, the orientation of the air flow transversal in respect to the advancing line does not allow the achievement of adequate efficiencies as the width of the conveyor system increases and, therefore, as the distance that the particulate matter must travel increases.
A further disadvantage of the known type separation plants is that the known type hoods have poor positioning flexibility, as they do not allow for adjustments to the inclination in respect to the sliding plane of the products.
A further disadvantage of known type separation plants is the need to design and manufacture custom-made hoods, according to the total area on which the suction is to be exercised. Known type hoods are made by bending metal sheet or by forming reinforced resins in an autoclave, which means that in the event of a change in the size of the hood, a significant modification of the manufacturing process is required, with a consequent increase in costs and a reduction in flexibility.
In addition, it is noted that due to the COVID-19 pandemic, it was necessary to sanitize environments to prevent the virus from spreading among workers.
The purpose of the present invention is to provide a separation process and a plant capable of overcoming the above mentioned drawbacks.
It is the purpose of the present invention to provide a separation process and a plant for sanitizing air in the work environment.
According to the present invention, a process and a plant are provided as mentioned in the appended claims.
The invention will now be described with reference to the attached drawings, which show non-limiting examples of embodiment thereof:
In
According to the shown example, the conveyor system T extends along a longitudinal axis Y1 and the advancing direction V1 of the products P is parallel to the longitudinal axis Y1.
According to the example shown in the figures, the products P are flat bodies, namely thin slabs having a length y1, that is, the extension along the longitudinal axis Y, and a width xb, that is, the extension along the axis X, much greater than the thickness zh, that is, the extension along an axis Z perpendicular to the advancing plane XY.
The products P have an upper surface cl substantially parallel to the advancing plane XY. Without losing generality, the products P may have different shapes and sizes and may not be flat.
It is noted that hereafter, the advancing plane XY is used as a reference for expressions such as horizontal (parallel to the advancing plane XY), vertical (perpendicular to the advancing plane XY) or the like.
According to what is shown in the figures, the products P are slabs (such as tiles). The products P may be made, for example, of ceramic material, composite material, wood, veneered material or the like.
Generally, during the processing of products P along the conveyor system T, dust is generated, which forms the particulate matter S together with other elements that may already be present in the environment. Along the conveyor system T there may be, in a known and non-shown manner, one or more workstations, for example a cutting, grinding, polishing or similar station.
The separation plant 1 according to the present invention may be installed at any position along the conveyor system T. In other words, the separation plant 1 may be installed along the conveyor system T either at a workstation or at any other position downstream or upstream of a workstation.
Advantageously, as will be better shown below, the separation plant 1 sucks in and separates the particulate matter S from the environment of the conveyor system T. Advantageously, the separation plant 1 is configured to sanitize the air of the environment of the conveyor system T so as to prevent the propagation of viruses or bacteria into the environment, as will be better shown below.
The separation plant 1 comprises a collection system 2, which is configured to suck in the particulate matter S from the environment using a carrier gas flow F1 (
The separation plant 1 further comprises a compressor 4, in particular a fan, connected to the collection system 2. The compressor 4 generates a depression so as to extract through the collection system 2 some gas, which constitutes the carrier gas flow F1, from the environment of the conveyor system T.
Advantageously, the separation system 3 is interposed between the collection system 2 and the compressor 4. In particular, the separation plant 1 comprises: a suction conduit 5, fluidically connecting the collection system 2 with the separation system 3, and an outlet conduit 6 fluidically connecting the separation system 3 with the compressor 4. According to the shown example, the separation system 3 is a cyclone separator. Without losing generality and according to non-shown variants the separation system 3 may be of a different type.
According to what is shown in detail in
Advantageously, the separation plant 1 further comprises a filtering device 7 arranged along the outlet conduit 6 and interposed between the separation system 3 and the compressor 4.
Advantageously, the filtering device 7 is also capable of filtering out viruses or bacteria carried by the particulate matter S. In particular, the filtering device 7 comprises a HEPA filter (High Efficiency Particulate Air filter) according to Standard EN 1822-2009 (EU), typically used for controlled atmospheres in clean rooms.
Advantageously, the separation plant 1 comprises a diffuser 8 installed downstream of the compressor 4 and getting a pushing flow F2 from the compressor 4 itself. Advantageously, the diffuser 8 is installed downstream of the collection system 2 and is configured to generate an air blade L1 going in a direction V2, which is against the advancing direction V1 of the product P (
The diffuser 8 is configured to blow an air blade L1 (
Advantageously, the air blade L1 impacts, in use, on the product P so as to cause the detachment of any dust particles S that have not separated from the product P under the action of the extraction of the carrier gas flow F1.
The angle of inclination α is such that, once detached, the particulate matter S is directed towards the suction mouth 9.
Advantageously, the angle of inclination a is greater than 90°. In particular, the angle of inclination a is ranging between 90° and 180°.
The carrier gas flow F1 has a component of horizontal motion V3 with direction opposite to the advancing direction V1 of the product P. In other words, the carrier gas flow F1 is against the advancing direction V1 of the product P. This allows to add, advantageously, the separation action of the air blade L1 in combination with the extraction of the carrier gas flow F1 obtaining a complete separation of the dust particles S from the product P. In this way, the separation plant 1 has an extremely high suction efficiency of the particulate matter S with values that can exceed 90-95%.
Advantageously, the collection system 2 and the diffuser 8 are side by side so as to demarcate with the upper surface cl of the product P a substantially closed suction chamber 10.
The only communication passage between the suction chamber 10 and the outside is given by the distance z1 between the plane xy1 of the suction mouth 9 and the upper surface c1 of the product P. Ideally, the distance z1 tends to be zero, i.e. to be as small as possible. A minimum distance z1 is due to prevent the collection system 2 from rubbing against the upper surface c1 of the product P and, thus, to avoid potential damage to the upper surface c1 by rubbing.
In other words, the suction chamber 10 is substantially a closed volume.
Advantageously, the air chamber 10 allows to confine in a closed volume either the pushing action of the air blade L1 or the extraction action of the carrier gas flow F1. In this way, the efficiency of the separation plant 1 is optimized either in terms of the power required for operation (extremely limited) or in terms of the percentage of particulate matter S sucked in.
According to what is shown in detail in
According to what is shown in
The hood 12 is a hollow body. The hood 12 comprises a wall 14 which delimits a suction area A (shown in
The connection 15 is internally hollow and has a suction cavity 19 that is configured to put the suction area A in communication with the suction conduit 5. The connection 15 is divided in a shaped profile portion 16 and in a coupling portion 18. The connection 15 is fluidly connected with the suction area A through an opening 20. The shaped profile portion 16 is interposed between the wall 14 and the coupling portion 18.
Advantageously, the shaped profile portion 16 is such as to generate a Venturi effect in the suction cavity 19 and by the opening 20. Along the shaped profile portion 16, the suction cavity 19 has a variable cross-sectional passage area. The passage area of the suction cavity 19 increases from the opening 20 towards the coupling portion 18. Advantageously, the profile of the passage area of the suction cavity 19 is also variable along the shaped profile portion 16.
According to the shown example, the passage area of the suction cavity 19 is substantially triangular in correspondence of the opening 20 (i.e., the opening 20 is substantially triangular in shape). The passage area of the suction cavity 19 is substantially circular at the coupling portion 18. The coupling portion 18 is substantially a tubular body having a longitudinal axis W.
Advantageously, the Venturi effect generated by the shape of the shaped profile portion 16 allows to amplify the depression of the carrier gas flow Fl and, consequently, the suction capacity of the hood 12.
Advantageously, since the suction area A is delimited by the wall 14 which is a bent wall of reduced height, the overall dimensions of the hood 12 are limited.
In particular, the hood 12 allows the extraction force of the hood 12 to be concentrated and localized in an area.
In other words, the hood 12 is substantially flat.
This increases the flexibility and ease of installation with a significant reduction in overall dimensions.
Advantageously, the suction area A is delimited by a single wall 14 which satisfies predefined technical specifications. This allows the hood 12 to be used as a central module of a more complex structure of the collection system 2 as will be better shown below. The fact that the hood 12 has a fixed geometry and dimensions allows technologies such as injection moulding of polymeric materials to be used for the realization thereof, which despite the high costs for the equipment allows a high productivity.
Advantageously, the hood 12 is made of polymeric material, this allows reducing the weight of the hood 12 by facilitating its transportation and installation.
The collection system 2 also comprises lateral wings 21 to adapt the width, i.e. the extension along the axis X, of the collection system 2 itself to the effective width of the conveyor system T.
The lateral wings 21 are not made in one piece with the wall 14, in other words they are distinct bodies each of which is connected to a respective longitudinal end of the wall 14. Each lateral wing 21 is a laminar body having a shape substantially similar to that of the wall 14. In other words, each lateral wing 21 constitutes an extension of the wall 14 along the longitudinal axis X2.
Advantageously, each lateral wing 21 is made by extrusion. In this way, for example, a piece of extrusion can be cut at will to obtain a lateral wing 21 of any length.
In other words, it is possible to replace a lateral wing 21 with another chosen within a group of lateral wings 21 differing from each other in length, i.e. extension along the longitudinal axis X2.
This allows the width of each collection system 2 to be adapted to the width of the conveyor system T according to the longitudinal extension of each lateral wing 21.
Advantageously, in this way, the extension along the longitudinal axis X2 of the collection system 2 is substantially equal to the width of the conveyor system T. In this way, it is ensured that the suction chamber 10 is closed, in use, inferiorly by the product P so as to reduce any air leakage.
According to the shown example, each lateral wing 21 may be releasably connected to the wall 14. In this way it is possible to change the width even of a collection system 2.
The collection 2 comprises two caps 22 (
According to the variant shown in
The collection system 2 has a leading edge 23 and longitudinally delimits the collection system 2 itself. The leading edge 23 is substantially parallel to the longitudinal axis X2.
According to the example shown in
According to the example shown in
In the example shown in
According to what is shown in
In the example of
According to a variant not shown, the separation plant 1 may comprise doubled components placed side by side but not communicating with each other, i.e. the hoods 12 may be placed side by side but not communicating with each other and the diffuser 8 instead of being of doubled length may be divided into two distinct bodies.
In use, the compressor 4 is activated so as to generate a depression such as to cause the air from the external environment to be sucked in through the collection system 2 generating a carrier gas flow F1. The carrier gas flow F1 entrains the particulate matter S within the collection hood 2 and into the suction conduit 5.
A dirty product P, i.e. on which material (dust, chips or the like) is deposited, which must be separated from the product P and constitutes at least part of the particulate matter S, advances in the advancing direction V1 and is made to slide below the separation hood 2.
By advancing below the separation hood 2, the product P inferiorly closes the suction area A of the separation hood 2 so as to inferiorly demarcate the suction chamber 10 (
Within the suction chamber 10 the carrier gas flow F1 entrains the particles as particulate matter S sucking it into the suction conduit 5.
According to what shown in
Advantageously, according to what is shown in
The particulate matter S is sucked along the suction conduit 5 and within the separation system 3.
Within the separation system 3 the particulate matter S is divided by the fluid (air) that constitutes the carrier gas flow F1. According to the example shown in the figures, the separation system 3 is a cyclone separator and the particulate matter S is made to accumulate within a special container 25 integrated into the separation system, or within a disposal bag or a pipe leading to a centralised tank 26 (the latter hypothesis is schematized by way of example in table 10).
Advantageously, the carrier gas flow F1 passes through the filtering device 7. In particular, the filtering device 7 comprises a HEPA-type filter, in this way it is possible to sanitize the carrier gas flow F1 by eliminating any viruses or bacteria and contributing to the sanitization of the environments. The filtering device 7 may comprise multiple degrees of filtration so as to allow the complete removal of particulate matter S from the carrier gas flow F1.
According to the variant shown in
Advantageously, according to
Advantageously, the separation plant 1 of the type described above can be easily adapted to any type of conveyor system. The separation plant 1 of the type described above is easy to install and takes up little space.
The separation plant 1 of the type described above requires reduced power compared to conventional separation plants.
Advantageously, the hood 12 of the collection system 2 can be made with standard components produced with large-scale production processes, for example moulding or extrusion. This allows economies of scale to be applied and reduces the cost of the separation plant 1.
The separation plant 1 of the type described above is independent and does not need to be connected to expensive centralised plants.
The collection system 2 has extremely reduced dimensions and is substantially flattened on the conveyor system T. This allows the collection system 2 to be installed in substantially any position.
Advantageously, the coupling portion 18 that is tubular and inclined in respect to the hood 12 allows a connection to be made with the suction conduit 5 that is inclined in respect to the advancing plane XY. This makes it possible to reduce the vertical dimensions of the separation plant 1 and to be able to adapt the collection system 2 also to already existing conveyor systems T with structural constraints.
Number | Date | Country | Kind |
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102020000012205 | May 2020 | IT | national |