CN115769039A

CN115769039A - Drying machine with cooling function

Info

Publication number: CN115769039A
Application number: CN202180043742.0A
Authority: CN
Inventors: 瓦尔特·帕拉迪尼; 阿尔贝托·帕拉迪尼
Original assignee: Sethec
Current assignee: Sethec
Priority date: 2020-07-30
Filing date: 2021-07-29
Publication date: 2023-03-07
Also published as: IT202000018580A1; WO2022024014A1; EP4189312A1; BR112022025864A2; MX2022016190A

Abstract

A dryer for granular or flake-like products, comprising: a drying chamber (2); two or more superimposed shelves (3) for supporting the products to be dried, at least one shelf being motorized to enable transport along a longitudinal direction (X); a first air circuit (4) for introducing hot air into the drying chamber; the method is characterized in that: the drying chamber (2) comprises a high temperature zone (21) and a low temperature zone (22) separated from each other, the high temperature zone (21) being connected to the first air circuit (4); the dryer comprises a second air circuit (5) for introducing air at low temperature, connected to the low temperature zone (22); the shelves (3) are prearranged so as to enable the transport of the products through the high-temperature zone (21) and then through the low-temperature zone (22).

Description

Drying machine with cooling function

The present invention relates to a dryer.

In particular, but not exclusively, the invention relates to a dryer for granular or flake-like material.

Generally, dryers perform the task of reducing or eliminating the moisture present inside the product as a residue of a previous treatment or production process.

The dryer is essentially defined by a drying chamber inside which a very hot and dry environment is created. The heat is generated by sources known in the art, such as for example gas burners, and is distributed inside the drying chamber using a forced air flow. Inside the drying chamber, the products are arranged to rest on one or more shelves, which are fixed or motorized along the longitudinal direction, which promotes the circulation of the hot air.

At the end of the drying process, the product leaving the dryer is at a relatively high temperature. In most cases, and in particular in the case of products destined to be bagged in the form of granules or flakes, it is necessary to wait for the product to cool. This involves an extension of the treatment time. Furthermore, the cooled product occupies space inside the apparatus.

The object of the present invention is to provide a dryer which makes it possible to eliminate the drawbacks of the drying chambers currently available.

A major further advantage of the dryer according to the invention is that the exiting product does not need to be cooled but is substantially ready for further processing, such as bagging.

Another advantage of the dryer according to the invention is that it is compact and efficient.

Other features and advantages of the invention will be apparent from the following detailed description of embodiments of the invention, illustrated by way of non-limiting example in the accompanying drawings, in which:

figure 1 is a side view of a dryer according to the invention;

figure 2 shows a left side view of the dryer of figure 1, with the side wall removed to show the interior;

figures 3 and 4 show a front view and a top view, respectively, of the first air circuit (4) of the dryer

A view;

figures 5 and 6 show a front view and a top view, respectively, of the second air circuit (5) of the dryer.

The dryer according to the invention comprises a drying chamber (2) inside which the drying process of the product takes place. The drying chamber is delimited in a known manner by a housing having at least one inlet opening (21) and at least one outlet opening (22).

The dryer comprises two or more further superimposed shelves (3) for supporting the products to be dried. The shelf (3) is preferably horizontal, but may also have a certain inclination with respect to the horizontal plane. The shelf (3) has a structure that promotes air circulation. The shelf (3) is motorized to enable the transport of products along the longitudinal direction (X). The shelf (3) is arranged perpendicular to the two side walls (2a, 2b) of the drying chamber (2); the side walls are parallel to the longitudinal direction (X).

In the embodiment shown, the shelves (3) are configured so that the products travel along the longitudinal direction (X) passing all the shelves (3). In particular, the shelves (3) are offset to enable transfer by dropping products from one shelf onto the shelf below.

In practice, upon entering the dryer, the product is fed into the upper shelf (3). The upper shelf (3) is arranged in a retracted position in an offset manner with respect to the lower shelf in the direction of advance of the products, so that the tip (3 b) of the upper shelf (3) protrudes into the lower shelf. This enables products falling from the upper shelf to be deposited on the lower shelf. In order to enable the passage of products by falling from each shelf (3) onto the shelf below, each shelf has, in the direction of advance of the products, an end (3 b) which protrudes onto the shelf below, and in particular onto the entry zone (3 a). In the embodiment shown, the end and inlet zones (3a, 3b) are located directly outside the drying chamber (2).

The shelves (3) preferably have an alternating direction of advance, i.e. each shelf has an opposite direction of advance with respect to the shelves of the upper and lower level. The products thus reverse their direction of advance as they pass from one shelf to the one below. In this way, the overall dimensions of the dryer along the longitudinal direction (X) can be contained.

The shelf (3) preferably comprises a plurality of through openings to promote the air flow. In the illustrated embodiment, at least one shelf (3), preferably each shelf (3), comprises a flexible element (31) made of a mesh or net structure.

The flexible elements (31) are arranged in a loop along a closed path having at least one straight upper section for supporting the product. The upper section is activated to move in a predetermined direction along the longitudinal direction (X).

In the embodiment shown, the flexible element (31) is folded around at least two rollers (32) positioned with their horizontal rotation axes parallel to each other. At least one of the rollers is motorized. As shown in fig. 2, the guide roller of each flexible element (31) substantially defines the end of the relative shelf (3). Considering the advancing direction of each shelf (3), the end of each shelf (3) protrudes onto the initial section of the shelf (3) below, i.e. the rollers arranged at the end of the relative shelf (3) protrude onto the initial section of the shelf (3) below.

The dryer according to the invention comprises a first air circuit (4) for introducing hot air into the drying chamber. The first air circuit (4) comprises a main fan (41) connected to a delivery manifold (42). In a manner known in the industry, in the case where the heating source is located outside the dryer, the main fan (41) is provided with an air intake to suck in air or ambient air that can be heated by means of the source located outside the dryer. In any case, the main fan (41) can be connected to an air recirculation duct present inside the drying chamber (2) in a manner known in the industry.

The manifold (42) is connected to a plurality of delivery conduits (43) distributed inside the high temperature zone (21). Each conveying duct (43) is provided with a plurality of outlet openings through which hot air is introduced into the high temperature zone.

In a preferred but not exclusive illustrated embodiment, the manifold (42) is positioned above the drying chamber (2). The delivery duct (43) descends from the manifold (42) in a substantially vertical plane. The conveying conduit (43) is preferably arranged at a side wall of the drying chamber (2).

Preferably, although not necessarily, the delivery conduits (43) are subdivided into two groups branching off from opposite regions of the manifold (42). The two sets of conveying ducts (43) are arranged on opposite side walls (2a, 2b) of the drying chamber (2). This makes it possible to maintain the manifold (2) in a position of centre of gravity with respect to the drying chamber and to distribute the conveying conduits (43) in a substantially symmetrical manner with respect to the manifold (42). In the embodiment shown, the first air circuit (4) comprises two fans (41) and two manifolds (42), independent of each other and flanking, each comprising its own delivery duct (43). This enables a better distribution of the hot air.

The conveying duct (43) comprises a transverse section (44) arranged substantially horizontally on a plane parallel to one of the shelves (3). The transverse section (44) of each conduit (43) is arranged substantially parallel above or below the shelf (3). For example, in the illustrated embodiment of two shelves 3 comprised in the high temperature zone (21), the conveying conduit (43) comprises two series of transverse sections (44): a first series located above the upper shelf (3) and a second series arranged above the lower shelf (3), i.e. between the upper shelf (3) and the lower shelf (3). The lateral portions (44) are preferably arranged coplanar on the same horizontal plane, and the outlet openings are arranged facing downwards and/or upwards. The downwardly facing outlet opening enables an efficient distribution of the hot air towards the lower shelf (3).

The dryer of the invention advantageously comprises a high temperature zone (21) and a low temperature zone (22) separated from each other, the high temperature zone (21) being connected to the first air circuit (4). The low-temperature region (22) is located below the high-temperature region (21).

The low-temperature zone (22) is connected to a second air circuit (5) for introducing air at a low temperature. Low temperature means a temperature substantially the same as the ambient temperature, or in any case significantly lower than the temperature present in the high temperature zone (21). When passing through the low temperature zone (22), the product cools significantly, reaching for example ambient temperature, and is therefore suitable for immediate bagging or packaging in another way, or for further processing, without waiting for further cooling.

The low-temperature zone (22) is provided with one or more shelves (3) that are completely similar to the shelves (3) of the high-temperature zone (21). These shelves (3) are prearranged so as to enable the transport of the products through the high-temperature zone (21) and then through the low-temperature zone (22). In particular, the shelves (3) present in the low temperature zone (22) are positioned similarly to the shelves of the high temperature zone, so that the products can pass by falling from each shelf onto the shelf below. In fact, the upper shelf (3) of the low temperature zone (22) is positioned so as to receive the products falling from the end of the lower shelf (3) of the high temperature zone (22). In other words, the end of the lower shelf (3) of the high temperature zone (21) protrudes onto the upper shelf (3) of the low temperature zone (22). In the embodiment shown, the low temperature zone (22) comprises only one shelf (3) which is also used for conveying the products to an unloading zone outside the dryer. A separating membrane (W) is interposed between the two zones (21, 22) to enable thermal insulation, apart from the openings necessary to allow the products to fall from one shelf to the other.

The second air circuit (5) comprises a main fan (51) connected to a delivery manifold (52). The main fan (51) of the second air circuit (5) is different from the fan (41) of the first air circuit (4), and the manifold of the second air circuit is different from the manifold of the first air circuit. In a manner known in the industry, the main fan (51) of the second circuit (5) is provided with an air intake that draws in cooling air. For example, the cooling air is air at ambient temperature.

The manifold (52) is connected to a plurality of delivery conduits (53) distributed inside the low temperature zone (22). In the embodiment shown, the manifold (52) is in the form of a duct which descends from the delivery of the fan (51) to the vicinity of the side wall of the drying chamber. At the low temperature zone (22), the manifold (52) is connected to a distributor section (53) which is arranged substantially horizontally and parallel to the longitudinal direction (X). From the distributor section (53) a plurality of delivery ducts (54) branch off, which are arranged substantially horizontally on a plane parallel to the shelf (3).

In the illustrated embodiment, the low temperature zone (22) comprises only one shelf (3), which is a shelf located in a lower position with respect to the other shelves. The conveying conduit (54) is arranged on the plane of the shelf (3) covering the low-temperature zone (22) inside the low-temperature zone (22). The conveying duct (54) is provided with a downward-facing and/or upward-facing discharge opening for introducing cooling air into the low temperature zone (22).

The suction circuit (6) visible in fig. 2 is preferably connected to the low-temperature region (22). The suction circuit (6) comprises a suction fan (61) connected to a suction manifold (62) provided with one or more suction openings located in a low temperature zone. In the embodiment shown, the fan (61) is located above the drying chamber (2) and the suction manifold comprises a duct descending from the fan (61) along the side wall (2 b).

The presence of a low temperature zone (22) separate from the high temperature zone (21) thus enables the product to be cooled to a desired temperature, for example to ambient temperature, so that the product is ready at the outlet of the dryer for bagging or packaging in another way, or for any other process requiring a temperature lower than the drying temperature.

Claims

1. A dryer for granular or flake-like products, comprising:

a drying chamber (2);

two or more superimposed shelves (3) for supporting products to be dried, at least one of said shelves being motorized to enable transport of said products along a longitudinal direction (X);

a first air circuit (4) for introducing hot air into the drying chamber;

the method is characterized in that:

the drying chamber (2) comprising a high temperature zone (21) and a low temperature zone (22) separated from each other, the high temperature zone (21) being connected to the first air circuit (4);

the dryer comprises a second air circuit (5) for introducing air at low temperature, connected to a low-temperature zone (22);

the shelves (3) are prearranged so as to enable the transport of the products through the high-temperature zone (21) and then through the low-temperature zone (22).

2. Dryer according to claim 1, wherein the shelves (3) are motorized to enable the transport of the products along the longitudinal direction (X) and are offset or have a plurality of openings in predetermined positions to enable the transfer by dropping the products from one shelf to the one below.

3. The drier according to claim 1, wherein the shelf (3) comprises a plurality of through openings to promote the air flow.

4. The dryer of claim 1, wherein:

at least one shelf (3) comprises flexible elements (31) with a net or mesh structure, arranged in a loop along a closed path with at least one straight upper section for the products;

the flexible element (31) is folded around at least two rollers (32) positioned with horizontal rotation axes parallel to each other, at least one of said rollers being motorized.

5. The dryer of claim 1, wherein:

the first air circuit (4) comprises a main fan (41) connected to a delivery manifold (42);

the manifold (42) is connected to a plurality of delivery conduits (43) distributed inside the high temperature zone (21).

6. The drier as claimed in claim 5, wherein the conveying duct (43) comprises a transverse section (44) arranged substantially horizontally on a plane parallel to one of the shelves (3).

7. The drier as claimed in claim 6, wherein the conveying ducts (43) are subdivided into two groups branching off from opposite regions of the manifold (42).

8. The dryer of claim 1, wherein:

the second air circuit (5) comprises a main fan (51) connected to a delivery manifold (52);

the manifold (52) is connected to a transverse distributor (53) arranged inside the low-temperature zone (22).

9. The drier according to claim 8, wherein the lateral distributor (53) is connected to a plurality of conveying ducts (54) arranged substantially horizontally on a plane parallel to one of the shelves (3).