EP0732558B1 - Apparatus for handling and circulating products in a dryer - Google Patents

Abstract

Wet clay products placed on trays (3) at a loading station (Db) are conveyed (11) to an entry zone (A), where vertical stacks 16 trays high are erected on the ends of 6 parallel conveyors (10), passing through the drier (B), by successive crane lifts (12,14,16). The drier doors open, allowing these stacks to enter, and 6 dried stacks to emerge at the other end (C). The latter, by a converse but similar lifting process (18,20,22), are broken down to single trays from which the products are removed (Da) and sent by conveyor (23) for firing, while the empty trays (3) return (11) to the loading station (Db). The operation continues cyclically, with step-by-step movement of the drier conveyors (10). A variant employs robot handlers at entry and exit, with continuously moving drier conveyors.

Description

The present invention relates to dryers such for example, but not limited to, that those used in the terracotta industry.

In the patent application filed the same day at name of the same applicant, a drying process has been described consisting of passing the air from the drying through alignments formed by stacks of racks of narrow width, that is to say carrying one to two products.

It is also known in baking ovens of the tunnel kiln type of employing conveyors to make circulate the products to be cooked from one end of the oven to the other.

The present invention relates to a device for handling and circulation of raw products in a drying installation, these raw products being carried by narrow racks stacked one on top of the other others over a significant height.

The present invention relates to a device for handling and circulation for drying products wines arranged on small width racks stacked on top of each other so as to align the small width and high height which is divided into four zones: a first zone in which the racks are stacked on top of each other others so as to form batteries which are charged on one or more parallel conveyors; a second zone constituting the dryer itself in which said conveyors are arranged parallel to each other others; a third area, located at the end of the second in which the stacks of trays are discharged of the parallel conveyor (s) and the racks are depilated; a fourth zone, going from the third to the first, in which the trays are unloaded from products having passed through the dryer, then reloaded with products to be dried and transported towards the start of the first zone, a conveyor circulating from the third zone to the first zone passing through the fourth zone.

Figure 1 : une vue générale en plan d'un dispositif selon l'invention,

Figure 2 : une vue latérale de l'installation illustrant la quatrième zone,

Figure 3 : une vue latérale partielle de l'installation illustrant la première zone et le début de la deuxième,

Figure 4 : une vue en coupe selon I-I de la figure 2,

Figures 5 et 6 : deux modes de réalisation de claies empilables.

Figure 7 : une variante de réalisation du dispositif selon l'invention.

By way of nonlimiting example and to facilitate understanding of the invention, the accompanying drawings show:

FIG. 1: a general plan view of a device according to the invention,

Figure 2: a side view of the installation illustrating the fourth zone,

Figure 3: a partial side view of the installation illustrating the first area and the start of the second,

FIG. 4: a sectional view along II of FIG. 2,

Figures 5 and 6: two embodiments of stackable racks.

Figure 7: an alternative embodiment of the device according to the invention.

Referring to these figures we see that the installation comprises four zones referenced from A to D; these four zones defining a drying cycle.

The products 6 are arranged on racks 3 which, as illustrated in Figures 5 and 6 are provided with means allowing them to be stacked. In Figure 5 we see that the racks 3 have an H section; in Figure 6 we see that each rack 3 is provided with feet 3a which rest on the screen located below.

These racks 3 are of small width, that is to say about 50 cm or the width of a brick or mechanical tile.

These racks can be square and then they are placed end to end or be rectangular as shown in Figures 1 to 6, their length being short (approximately four times the width according to the example shown).

With these racks 3 we will make stacks 2 which will have the characteristic of being narrow and significant height (about 1.50 m). These stacks are placed end to end on conveyors to achieve a kind of wall called alignment that will be crossed perpendicularly by the drying air flow as this is described in the aforementioned patent application.

The racks 3 loaded with wet products 6, arrive in 8 in zone A from zone D by a conveyor 11.

These racks 3 are stacked on top of each other in zone A and placed on conveyors 10. In the example shown there are six parallel conveyors 10 and which extend in a direction perpendicular to that of the longitudinal axis of zone A.

Preferably, as shown in Figures 1 and 4 the trays are entered one by one by one first clamp 12 which performs a first stack of four racks placed on a conveyor 13 perpendicular to the conveyor 11. Then a second clamp 14 grips each group of four racks and stack four groups of four racks on a fixed support 15 so as to produce a stack 2 comprising sixteen racks 3 stacked one on the other on others. Finally, a third clamp 16 grips 2 stacks and transport them to the conveyors 10 starting with the furthest conveyor 10a, then by loading the conveyor 10b, then the conveyor 10c, etc.

The invention is not limited to the example shown in which each alignment has four times four racks. The first partial stacking can have "n" racks 3 and the final stacking a number "m" partial stacking with "n" racks.

When all the conveyors 10 are loaded, the closing means, for example flaps 17, which seal the drying chamber 1 at each of its ends are open and the conveyors are set action so as to penetrate the stacks 2 to the interior of the drying chamber 1, after which the conveyors 10 are stopped, the flaps 17 closed and a new loading cycle for the ends of the conveyors 10 begins.

The alignments 2 thus cross step by step the zone B which constitutes the dryer proper. Ways are not described in detail and may be advantageously those described in the patent application mentioned above filed the same day.

The ends of the conveyors 10 protrude in zone C in the same way as in zone A.

A first clamp 18 (analogous to clamp 16) unloads the stacks 2 on a support 19 (analogous to support 15); a second clamp 20 (analogous to the clamp 14) undo the stack by taking packs of four racks; a transporter 21 similar to the transporter 13 moves the packs of four trays which are taken one by one by a clamp 22 similar to the clamp 12 and placed on the conveyor 11 which takes them to zone D.

At the beginning of zone D is a Da post where the dried products 6 are removed from the racks 3 and placed on a carrier 23 by which they are transported to cooking facilities.

Racks 3, empty, are routed by the conveyor 11 towards zone A.

On the way, they pass by a Db station where 6 drying products are placed on the trays which arrive thus loaded at the start of zone A where they are stacked as described above.

Preferably, the conveyors 10 and 11 are chain conveyors, but they can be wheeled.

Figure 7 shows an alternative embodiment in which the same elements carry the same references.

The installation includes the four zones A, B, C, D, but zones A, C and D use a common conveyor 11 and the unstacking tongs are replaced by robots.

Zone A includes a robot 30, which captures the racks 3 loaded with products to be dried and placed on a conveyors 10; the robot stacks the racks 3 together on the others until alignment 2 has reached the desired height or stacking of the desired number of racks 3.

Zone C includes a robot 31, which unstacks the racks 3. In addition, this robot removes dry products from racks 3 and places them on the conveyor 23 by which they are discharged to the baking oven. 3 empty trays are placed on the conveyor 11.

The empty 3 racks arrive in zone D via the conveyor 11 and passes under a loading device 32 which places fresh products to dry on the racks 3. This loading member 32 may include a molding machine so the clay tablets are molded and then loaded on racks 3. This loading member corresponds to item Db from the previous example.

When the conveyors 10 are loaded, the enclosure 1 opens, the conveyors 10 are started during the time required to move a length equal to that of alignments 2, so that those who are at start of zone B enter the dryer and those who are at its other end come out; then enclosure 1 is closed. Racks 2 of racks 3 stacked one on the others cross the enclosure by walking step by step as in the previous example.

It is possible with the device according to this variant of the invention to load the three conveyors 10a, 10b and 10c and when they are ready to implement them movement all three together after opening closing means, for example doors 27, of the dryer.

But above all, it is possible to activate them separately. When the robot 30 has finished making a alignment 2 of racks 3 on one of the conveyors 10, we open the two doors of the enclosure and we advance this conveyor. After which, the robot 31 loads the conveyor following. This allows drying cycles different depending on the conveyors.

In this case, it is preferable to have the closing means, an entry door 27 and a door outlet 27, for each conveyor 10.

You can also delete these doors and continuously advance the conveyors either at the same speed either at different speeds by programming in consequently robots 30 and 31.

Claims (15)

1. A handling and circulation device for drying raw products (6) arranged on grates (3), of low width, stacked one upon another so as to effect an alignment (2) of low width and of great height, which is divided into four zones: a first zone (A) in which said grates (3) are stacked one upon another so as to form piles which are loaded onto a plurality of parallel conveyors (10); a second zone (B), forming the dryer (1) proper, through which said parallel conveyors (10) pass; a third zone (C), located at the other end of the second zone (B), in which the stacks of grates (3) are unloaded from the conveyors and the grates (3) are unstacked; a fourth zone (D) extending from the third zone (C) to the first zone (A) in which the grates (3) are unloaded of the products (6) which have passed through the dryer (1), and then are reloaded with products (6) to be dried and brought towards the start of the first zone (A), a conveyor (11) circulating from zone (C) to zone (A), passing through zone (D).
2. A device according to Claim 1, in which the first zone (A) comprises a first clasping means (12) which unloads the conveyors (11) bringing the grates (3) loaded with products to be dried and forms a partial stack thereof.
3. A device according to Claim 2, in which a second clasping means (14) stacks the partial stacks one upon another to obtain the final stack (2).
4. A device according to Claim 3, in which a third clasping means (16) transports the stacks (2), when they are finished, to the starts of the conveyors (10) which project into the first zone (A).
5. A device according to Claims 2 to 4, in which the partial stack comprises four grates (3) and the finished stack (2) a stack of four partial stacks, i.e. sixteen grates (3).
6. A device according to Claims 2 to 4, in which a partial stack comprises "n" grates (3) and a final stack (2) "m x n" grates.
7. A device according to any one of the preceding claims, in which the drying enclosure (1) comprises a closure shutter (17) at each of its ends.
8. A device according to Claim 7, in which when all the conveyors (10) projecting into the zone (A) are loaded, the shutters (17) are opened and the conveyors (10) are actuated to cause the alignments (2) to penetrate into the drying enclosure (1) forming the second zone (B), after which the shutters (17) are closed again.
9. A device according to any one of the preceding claims, in which the stacks (2) arriving in the third zone (C) are dismantled by means similar to those used in the first zone (A) to form them.
10. A device according to Claim 9, in which the grates (3), after unstacking, are laid one by one on a conveyor (11) which constitutes the fourth zone (D) extending from the end of the third zone (C) to the start of the first zone (A).
11. A device according to Claim 10, in which in the fourth zone (D) the grates (3) are unloaded of their dried products and then reloaded with products to be dried.
12. A device according to Claim 11, in which each of the zones (C), (D) and (A) comprises a robot, the robot (31) of zone (C) unstacking the grates (3) which have emerged from the enclosure (1) and placing them on the conveyor (11) after having removed the dried products therefrom; the device (32) of zone (D) loading the grates (3) with fresh products to be dried; the robot (30) of zone (A) loading the grates (3) onto the conveyors (10) by stacking them one upon another.
13. A device according to Claim 12, comprising a single closure means (27) at the entry and a single closure means (27) at the exit which open and close together, the three conveyors (10) being actuated together and the alignments (2) passing through the enclosure (1) step by step at the same rate.
14. A device according to Claim 13, in which an entry closure means (27) and an exit closure means (27) correspond to each conveyor (10), such that each conveyor (10) can advance step by step individually.
15. A device according to Claim 13, in which the enclosure (1) does not comprise closure means, the conveyors (10) moving continuously either at the same speed or at different speeds.

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