Dryers for tiles or slabs

Abstract

A dryer for ceramic products, such as slabs or tiles, comprising: a drying chamber (1); at least one drying channel (10) comprising a shelf (11) for one or more ceramic products; at least two manifolds (20), respectively located above and below the shelf (11), each manifold being connected to a conditioned air source. The manifold (20) located above the shelf (11) has an extended shape and is provided with a flat lower surface (21a), which covers at least a portion of the shelf (11) in a plan view and is provided with a plurality of lower openings (22a) for discharging conditioned air into the drying channel (10). The manifold (20) located below the shelf (11) has an extended shape and is provided with a flat upper surface (21b), which covers at least a portion of the shelf (11) in a plan view and is provided with a plurality of upper openings (22b) for discharging conditioned air into the drying channel (10).

Description

[0001] The present invention relates to a dryer, and more particularly to a dryer for tiles or slabs.

[0002] In the field of producing tiles and slabs, dryers are currently available to reduce the moisture in the product before firing. In short, dryers are provided to regulate the moisture in the product so that during the firing process the moisture in the product is not too much. In fact, too much moisture means a high risk of cracking of the product during firing.

[0003] Currently available dryers include a series of mutually overlapping roller planes on which the product to be dried is positioned. Each roller plane defines a channel of the dryer, and a dryer may have one or more overlapping channels. The roller planes are preferably motorized to guide the product from the external transport plane into the channel of the dryer.

[0004] A hot air stream is delivered into each channel of the dryer so that it hits the product and reduces the moisture in the product. In current dryers, the hot air is delivered into each channel through a plurality of tubular ends, which are arranged above and below the roller plane of the channel. The ends are arranged parallel to the rollers forming the roller plane, i.e. they are arranged inside the channel transversely to the direction of advancement of the product. For delivering the hot air, the ends are provided with a series of openings distributed on the surface of the ends themselves.

[0005] In current dryers, it is not possible to regulate the hot air flow within the individual ends. This essentially means that it is not possible to regulate the moisture of all the products present inside the dryer uniformly. In other words, since the airflow entering the individual ends cannot be varied, the products in the areas defined as having a greater airflow are dried more, while the products in the areas with a lesser airflow are dried less. In fact, it is inevitable that there are areas of different temperatures inside the dryer, since the hot air changes temperature along the distribution ends. Products located in the cooler areas of the dryer may not be dried sufficiently and therefore be damaged during the firing process.

[0006] Examples of heating machines which partially modify the hot air distribution in the heating chamber are known from documents EP2741037, US4059399, US5970626.

[0007] The object of the present invention is to provide a dryer which eliminates the disadvantages of currently available dryers.

[0008] An advantage of the dryer according to the invention is that it enables a uniform and homogeneous distribution of the hot air.

[0009] Another advantage of the dryer according to the invention is that it enables the hot air flow to be adjusted differently in two or more inner zones of the drying tunnel.

[0010] Another advantage of the dryer according to the invention is that it enables effective and rapid cleaning.

[0011] Another advantage of the dryer according to the invention is that current dryers can be replaced without any substantial modifications to the surrounding equipment and machinery.

[0012] Other features and advantages of the invention will become more apparent from the following detailed description of an embodiment of the invention, illustrated by way of non-limiting example in the accompanying drawings, in which:

[0013] - Figure 1 is an isometric view of a portion of a dryer according to the present invention;

[0014] - Figure 2 is an isometric view of a dryer according to the present invention;

[0015] - Figure 3 Shows some parts removed Figure 2 Dryer;

[0016] - Figure 4 Shown on an enlarged scale Figure 3 Details;

[0017] - Figure 5 is an isometric view of a portion of a dryer according to the invention and in a second embodiment;

[0018] - Figure 6 Shown on an enlarged scale Figure 5 The dryer area;

[0019] - Figure 7 Shown from different angles Figure 6 area;

[0020] - Figure 8 Shows Figure 5 A vertical front view of an enlarged portion of .

[0021] The dryer according to the invention comprises a drying chamber (1) into which the product to be dried is conveyed. The drying chamber (1) is contained in a housing, which is not shown for better viewing of the inner area of ​​the dryer. The drying chamber (1) comprises at least one drying passage (10) along which the product to be dried is conveyed. The drying passage comprises a shelf (11) arranged to support the product. In the embodiment shown, the shelf (11) is a roller plane for the entry and exit of the product from the drying passage (10), which enables the product to advance in a main direction (X).

[0022] The drying passage (10) is defined by two manifolds (20) located above and below the shelf (11). Each manifold (20) is connected to a conditioned air source. Each manifold (20) essentially performs the function of directing and dispersing conditioned air into the drying passage (10). The conditioned air can be produced by devices and means known in the art. For example, the air can be conditioned by heating with one or more burners.

[0023] In the preferred but non-exclusive embodiment shown, the dryer comprises a plurality of drying channels (10) which are parallel and overlap each other. A manifold (20) is arranged above and below each drying channel (10), i.e., two drying channels (10) are separated by a manifold (20). The manifold (20) inserted between two overlapping drying channels (10) is configured to disperse the conditioned air into the two drying channels (10), i.e., disperse upward and downward. The following description is mainly directed to one drying channel (10), but it is obvious that it can relate to each of the drying channels (10).

[0024] Advantageously, the manifold (20) according to the invention has an extended configuration and is provided with a lower surface (21a) and an upper surface (21b). Preferably, both surfaces (21a, 21b) are flat.

[0025] Considering the drying tunnel (10), the lower surface (21a) occupies at least a portion of the lower shelf (11) in plan view, while the upper surface (21b) occupies at least a portion of the upper shelf (11) in plan view.

[0026] The lower surface (21a) of the upper manifold (20) is provided with a plurality of openings (22a) for discharging conditioned air into the drying duct (10) below. The upper surface (21b) of the lower manifold (20) is provided with a plurality of upper openings (22b) for discharging conditioned air into the drying duct (10) above.

[0027] Unlike currently available dryers, which are provided with a certain number of tubular manifolds above and below the shelf (11), each shelf (11) of the dryer according to the invention has only two manifolds (20), one located above the shelf (11) itself and the other located below the shelf itself. Each manifold (20) substantially comprises a single volume supplied with conditioned air to be introduced into the drying channel (10). The conditioned air is evenly and homogeneously distributed into the manifold (20), so that the airflow outflowing from the openings (22a, 22b) is also even and homogeneous in terms of flow and temperature. Preferably, the openings (22a, 22b) are distributed substantially on all lower and upper surfaces (21a, 21b) so that the air is completely evenly and homogeneously dispersed.

[0028] Preferably, the lower surface (21a) is parallel to the lower shelf (11), so that the various airflows flowing out of the lower opening (22a) travel substantially the same distance before encountering the shelf (11), thereby maintaining homogeneous properties. Similarly, the upper surface (21b) is parallel to the upper shelf (11), so that the various airflows flowing out of the lower opening (22a) travel substantially the same distance before encountering the shelf (11), thereby maintaining homogeneous properties.

[0029] Preferably, the lower surface (21a) has an extension substantially identical to that of the shelf (11) below. Thus, the entire shelf (11) is hit by an air flow with homogeneous and uniform properties coming from the manifold (20) and passing through the lower opening (22a). Preferably, the upper surface (21b) has an extension substantially identical to that of the shelf (11) above. Thus, the entire shelf (11) is hit by an air flow with homogeneous and uniform properties coming from the manifold (20) and passing through the upper opening (22b).

[0030] Due to the properties of the manifolds (20), the products arranged on the shelves (11) inserted between the two manifolds (20) are subjected to a uniform action in each area of ​​the shelves (11). Therefore, the products leaving the dryer have a constant homogeneous and uniform properties, especially in terms of humidity.

[0031] Preferably, conditioned air is supplied to each manifold (20) in countercurrent with respect to the direction of advance of the products on the shelves (11).

[0032] Advantageously, the dryer comprises a collection drawer (60) located above the manifold (20) placed below the shelf (11). Specifically, the collection drawer (60) is arranged above the upper surface (21b) of the manifold (20) placed below the shelf (11). In the illustrated embodiment comprising various shelves (11), the collection drawer (60) can be located above each manifold (20), i.e. the collection drawer can be inserted between each manifold (20) and the shelf (11) above the manifold (20). The following description mainly relates to the manifold (20) and the collection drawer (60) thereon, but it is obvious that it can relate to each manifold (20) present in the dryer.

[0033] The collecting drawer (60) is provided with a through hole (61) configured to allow air to flow from the manifold (20) below, in particular from the upper opening (22b) of the manifold (20). In other words, the collecting drawer (60) is inserted between one shelf (11) and the manifold (20) below. Thus, all particles or residues separated from the products on the shelf (11) fall and are deposited on the collecting drawer (60) without accumulating on the manifold (20) below.

[0034] Advantageously, the collection drawer (60) can be removed from the dryer. For this purpose, the collection drawer (60) is housed in the above-mentioned position inside the dryer by means of guides not shown and / or a slidable and / or removable attachment system as known to a person skilled in the art. Thus, the collection drawer (60) can be quickly removed and cleaned for subsequent reinsertion into the dryer. Preferably, but not necessarily, the dryer can be provided with an openable and / or removable door and / or panel to facilitate the removal of the collection drawer (60).

[0035] In the preferred but non-exclusive embodiment shown, the collection drawer (60) has a substantially flat shape. Preferably, the collection drawer (60) is substantially located on a main plane parallel to the shelf (11). The through holes (61) are substantially aligned with the upper opening (22b) of the manifold (20). In the embodiment shown, the through holes (61) of the collection drawer (60) and the upper opening (22b) of the manifold (20) are distributed along mutually parallel rows perpendicular to the main direction (X). Preferably, the through holes (61) of the collection drawer (60) and the upper opening (22b) of the manifold (20) are aligned in a vertical plane perpendicular to the main direction (X).

[0036] In the illustrated embodiment, the collection drawer (20) includes a plurality of protruding ribs (62) extending away from the manifold (20), i.e., toward the upper shelf (11). Preferably, the ribs (62) are hollow and open toward the manifold (20) below. In the illustrated embodiment, the ribs (62) have a V-shaped configuration, with the apex of the rib turned toward the upper shelf (11) and the rib open toward the lower manifold (20).

[0037] In the preferred but non-exclusive embodiment shown, the shelf (11) is substantially horizontal and the ribs (62) extend vertically upwards, i.e. towards the upper shelf (11). Preferably, the ribs (62) are parallel to each other and oriented perpendicularly to the main direction (X). Preferably, the through holes (61) are arranged in the vertex region of the ribs (62). Specifically, the through holes (61) are distributed along the vertex of the ribs (62). Thus, the ribs (62) convey the air from the manifold (20) below its own vertex and thus convey it towards the through holes (61). This promotes the dispersion of air towards the lower shelf (11). In addition, the ribs (62) divert particles or residues falling from the upper shelf (11) away from the through holes (61) arranged at the vertex of the ribs themselves, thereby preventing these particles or residues from blocking the through holes (61) and the upper opening (22b) of the lower manifold (20). The particles or residues are collected in the area of ​​the drawer (60) inserted between the ribs (62).

[0038] In the embodiment shown, in which the shelves (11) are defined by a plurality of mutually coplanar rollers, the ribs (62) with through holes (61) are distributed at a spacing substantially equal to the spacing of the rollers separating the shelves (11). This promotes uniform distribution of air relative to the shelves (11) themselves.

[0039] In the embodiment shown, each manifold (20) has a flattened box shape, defined below by a lower surface (21a) and above by an upper surface (21b). This shape is particularly useful for being able to position the shelf (11) between two mutually overlapping manifolds (20). In other words, each drying channel (10) is defined above and below by two manifolds (20), i.e. each shelf (11) is inserted between two manifolds (20), i.e. a lower manifold and an upper manifold. In the preferred but non-exclusive embodiment shown, the lower surface (21a) and the upper surface (21b) are identical to each other in shape and size.

[0040] Preferably, each manifold (20) comprises a housing (23) having a prismatic shape having a height (h) smaller than two orthogonal dimensions of the lower surface (21a). For example, if the lower surface has a length measured parallel to the main direction of advancement (X) of the product and a width measured perpendicular to the width, the height (h) is smaller than the width and length of the lower surface (21a). For example, the height (h) is approximately 1 / 10 of the length of the lower surface (21a).

[0041] In an advantageous possible embodiment, each manifold (20) comprises two or more volumes (2A, 2B, 2C) separated by one or more partitions (24, 25) isolating the volumes (2A, 2B, 2C) from each other. Inside each volume, the conditioned air is evenly distributed, thus presenting homogeneous properties and passing through the openings (22a, 22b) facing each other in each drying chamber (10) with an equally homogeneous airflow distribution.

[0042] Providing two or more separate volumes also enables the conditioned air flow to be regulated independently within each volume. Thereby, any inhomogeneities in the ambient conditions that may occur inside each drying tunnel (10) can be compensated. It should be noted that if the product located inside a certain area of ​​the drying tunnel (10) (for example at the outlet of the dryer) has a different humidity than other products or other product areas, the conditioned air flow supplied to the area concerned can be intervened to correct the difference in moisture.

[0043] For example, in a first solution, each volume (2A, 2B, 2C) can be connected to a corresponding conditioned air source. For this purpose, each volume (2A, 2B, 2C) can be provided with a corresponding inlet duct (20A, 20B, 20C) isolated from each other.

[0044] In a second possible solution, alternatively or in combination with the first solution, each inlet duct (20A, 20B, 20C) is provided with a flow regulator (5A, 5B, 5C). In the second solution, there may be a single conditioned air source. In order to condition the air delivered to the drying tunnel (10) in different ways, the air flow supplied to each volume (2A, 2B, 2C) can be regulated in different ways by means of the flow regulators (5A, 5B, 5C). It should be noted that, for example, if the product in a certain area of ​​the drying tunnel (10) has a higher humidity than the product in other areas, the air flow supplied to this area can be increased by means of the flow regulators (5A, 5B, 5C).

[0045] In the preferred but non-exclusive embodiment shown, the flow regulators (5A, 5B, 5C) are in the form of butterfly valves, i.e. each of them comprises a plate rotatable about an axis of rotation transverse to the direction of air flow. Each plate is rotatable between a closed position, in which the plate is arranged transversely to its own inlet duct (20A, 20B, 20C), thereby closing its section to prevent air flow, and an open position, in which the plate is oriented in a plane substantially parallel to the plane of air flow, thereby only minimally closing a section of its own inlet duct (20A, 20B, 20C). Between the open position and the closed position, each valve can be arranged in an intermediate position to regulate a section of its own inlet duct (20A, 20B, 20C). The regulation of each valve can be performed manually or automatically in a manner known to a person skilled in the art.

[0046] Preferably, but not necessarily, the drying chamber (1) is connected to an air extraction circuit. Such a circuit, known to those skilled in the art, envisages one or more suction hoods (30) located inside the drying chamber (1), through which the air can be exhausted wholly or partially to the outside, or the air can be reintroduced wholly or partially into the dryer itself. In the embodiment shown, each shelf (11) has a suction hood (30). Preferably, each hood (30) is arranged substantially coplanar with the manifold (20) overlapping the shelf (11) itself. For example, the hood (30) can be provided inside the same box-shaped body that defines the manifold (20). As Figure 3 As shown, the suction hood (30) can be separated from the manifold (20) by a transverse wall (32). The use of an air extraction circuit can further improve the homogeneity and uniformity of the environmental characteristics inside the drying chamber (1).

Claims

1. A dryer for ceramic products, the dryer comprising: Drying chamber (1); at least one drying tunnel (10) comprising shelves (11) for one or more ceramic products; at least two manifolds (20), located above and below the shelf (11), respectively, each of the manifolds being connected to a conditioned air source; Features: The manifold (20) located above the shelf (11) has an extended shape and is provided with a flat lower surface (21a), the lower surface covering at least a portion of the shelf (11) in a plan view and provided with a plurality of lower openings (22a) for discharging conditioned air into the interior of the drying channel (10); The manifold (20) located below the shelf (11) has an extended shape and is provided with a flat upper surface (21b), the upper surface covering at least a portion of the shelf (11) in a plan view and provided with a plurality of upper openings (22b) for discharging conditioned air into the interior of the drying channel (10); The lower surface (21a) has an extension substantially the same as the extension of the shelf (11) below; The upper surface (21b) has an extension substantially identical to that of the upper shelf (11), wherein the manifold (20) comprises two or more volumes (2A, 2B, 2C) separated by one or more partitions (24, 25) isolating the volumes (2A, 2B, 2C) from each other, wherein each of said volumes (2A, 2B, 2C) is connected to a respective conditioned air source, wherein each of the volumes (2A, 2B, 2C) is provided with a respective inlet duct (20A, 20B, 20C) isolated from each other, The dryer comprises a collection drawer (60) located above the manifold (20) and arranged below the shelf (11), The collecting drawer (60) is provided with a through hole (61), wherein the through hole is configured to allow air from the manifold (20) below to flow. The collection drawer (60) comprises a plurality of protruding ribs (62) extending toward the shelf (11) above and opening toward the manifold (20) below, wherein the through holes (61) are arranged in the top end region of the ribs (62).

2. The dryer according to claim 1, wherein: The lower openings (22a) are substantially distributed over the entire lower surface (21a).

3. The dryer according to claim 1, wherein: The upper openings (22b) are substantially distributed over the entire upper surface (21b).

4. The dryer according to claim 1, wherein: Each manifold (20) has a flat box shape, the lower portion of the manifold is defined by the lower surface (21a), and the upper portion of the manifold is defined by the flat upper surface (21b).

5. The dryer according to claim 1, wherein: The manifold (20) comprises a housing (23) having a prismatic shape, the housing having a height (h) that is smaller than two orthogonal dimensions of the lower surface (21a).

6. The dryer according to claim 1, wherein: The lower surface (21a) is parallel to the shelf (11) below.

7. The dryer according to claim 1, wherein: The upper surface (21b) is parallel to the upper shelf (11).

8. The dryer according to claim 1, wherein: Each of the inlet ducts (20A, 20B, 20C) is provided with a flow regulator (5A, 5B, 5C).

9. The dryer according to claim 1, comprising a plurality of drying channels (10) parallel to and overlapping each other, wherein: Two adjacent drying passages (10) are separated by the manifold (20) provided with the lower opening (22a) on the lower surface (21a) and the upper opening (22b) on the upper surface (21b) to deliver conditioned air toward the lower shelf (11) and the upper shelf (11).

10. The dryer according to claim 1, wherein The collection drawer (60) is removable.

11. The dryer according to claim 1, wherein the ceramic product is a slab or a tile.

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