EP0590368A1

EP0590368A1 - Vertical drying kiln for tiles with blown-air drying

Info

Publication number: EP0590368A1
Application number: EP93114405A
Authority: EP
Inventors: Rodiero Alieri
Original assignee: Sacmi Imola SC
Current assignee: Sacmi Imola SC
Priority date: 1992-09-29
Filing date: 1993-09-08
Publication date: 1994-04-06
Also published as: ITBO920333A1; IT1258328B; ITBO920333A0

Abstract

Vertical drying kiln for tiles, comprising a container (1) which is vertically divided so as to form two compartments (3,4) connected at the top and at the base, a pair of chains (6,7) closed in a loop moving inside the compartments and supporting the baskets (8) which carry the tiles, characterized in that the baskets have tubular elements (22) between the shelves (18) which support the tiles (19) and that inside the compartments (3,4) there are chambers (26) connected to means (28,29) for feeding drying air and provided with holes (31) which can be connected to the tubular elements; the tubular elements are provided with openings (23) for expelling the drying air between the layers of tiles.

Description

The present invention relates to a vertical drying kiln for tiles with blown-air drying.
Known vertical drying kilns for tiles comprise a container which is vertically divided so as to form two compartments which are mutually connected at the top and at the base; a pair of chains closed in a loop moves inside said compartments and supports the baskets which carry the tiles.
In vertical drying kilns of this type, the drying air is conveyed inside the container so as to flow as much as possible through the baskets and flow around the tiles so as to remove their humidity.
The effectiveness of these known drying kilns is conditioned by the fact that conveyance of the drying air is highly irregular and can be controlled only in a very approximate manner, and this negatively affects the efficiency of the drying kiln.
A principal aim of the present invention is therefore to provide a vertical drying kiln which allows to obtain a significantly greater efficiency than conventional ones.
With this and other aims in view, there is provided, according to the present invention, a drying kiln which is characterized in that the baskets have tubular elements between the tile supporting shelves and that inside said compartments there are chambers connected to means for feeding drying air and provided with holes which can be connected to said tubular elements, said tubular elements being provided with openings for expelling the drying air between said layers of tiles.
Further characteristics of the present invention will become apparent from the following description of some preferred embodiments thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

figure 1 is a partially sectional perspective view of a drying kiln according to the invention;
figure 2 is a plan sectional view of the drying kiln of figure 1;
figure 3 is a side elevation sectional view of the drying kiln of figure 1;
figures 4, 5 and 6 are respectively a side elevation sectional view, a front elevation view and a plan view of a tile supporting basket;
figure 7 is a side elevation sectional view, similar to the view of figure 3, but taken between the baskets and the chambers for the conveyance of the drying air; and finally
figures 8 and 9 are enlarged-scale detail views of two different embodiments of the connection between the chambers and the tubular elements.

In the figures, the drying kiln is generally designated by the reference numeral 1 and comprises a container 2 which rises like a prism-shaped tower and is divided into two compartments 3 and 4 (figure 2) by partitions 5.
The compartments are mutually connected at the top and at the base, and the pair of chains 6 and 7 for supporting the tile-carrying baskets 8 run in said compartments. The chains 6 and 7 are wound around respective sprockets 9, 9a (figure 3) and are jogged by means of a gearmotor 10.
The reference numeral 11 designates the region for loading the tiles to be dried in the baskets 8, whereas the dried tiles are unloaded onto a removal conveyor 12 which is arranged at the base between the compartments 3 and 4.
Each one of the baskets 8 comprises two flat and mutually parallel side walls 13 and 14 which are constituted by metal plates mutually connected by metallic profiled elements 15.
Openings 16 are formed in the side walls 13 and 14 and are arranged along equidistant horizontal parallel rows and along equidistant vertical columns.
The flared ends 17 of tubular rollers 18 engage in the opening 16, as shown by the enlarged-scale detail view of figure 8; said rollers are smaller than said openings and form the resting surfaces for the tiles 19.
The tiles 19 are fed onto the rollers 18 by means of appropriate devices 20 and 21 which comprise oppositely arranged mandrels which are actuated so as to engage in the opposite ends of the rollers which form each surface.
Thus, by rotating the mandrels it is possible to rotate the rollers 18 and cause the advancement of the dried tiles toward the removal conveyor to unload them onto said conveyor and at the same time load the tiles to be dried into the basket.
Further layers of tubular elements are interposed between the superimposed layers of rollers 18 and are constituted by tubes 22 which are parallel to rollers 18.
The tubes 22 are arranged vertically and horizontally equidistant with respect to each other, and their opposite ends are rigidly coupled to the side walls 13 and 14.
Openings 23 are furthermore formed in the tubes 22, are distributed longitudinally and are orientated toward the superimposed layers of tiles supported by the rollers.
The described drying kiln is completed by chambers 24, 25 and 26, 27 which extend inside the compartments 3 and 4 adjacent to the side walls 13 and 14 of the baskets, along the ascending and descending straight portions of the chains 6 and 7.
The chambers 24-27 are connected to a source of hot drying air which is generated by a pair of burners 28 (one for each side of the drying kiln) and is kept circulating inside the container 2 by ventilation means 29.
The chambers 24-27 are ducts having a rectangular cross-section and in each of which there is a channel 30 which is open toward the baskets in order to allow the passage of the ascending and descending portions of the chains and of the supporting arms of the baskets.
Holes 31 are formed on the faces of the chambers 24-27 which are directed toward the baskets; respective conical nozzles 32 extend from said holes toward the sides 13 and 14 of the baskets but remain spaced from said sides.
The nozzles 32 have the same distribution as the openings 33 for access into the tubes 22, so that at all times, every nozzle is aligned with a respective tube 22.
The operation of the described drying kiln is fully evident from the description given.
In particular, the hot air generated by the burners 28 is conveyed into the chambers 24-27, from which it is directed into the tubes 22 through the nozzles 32. The air then flows out through the openings 23 and strikes directly the opposite faces of the tiles which rest on the rollers 18, effectively removing humidity from said tiles.
It should be noted that the frustum-shaped nozzles 32 produce, due to the Venturi effect, the aspiration of air from the annular interspace formed between the adjacent ends of the nozzles and of the tubes 22.
Therefore there is no loss of hot air in the transit between the chambers 24-27 and the tubes 22.
Naturally, the pitch of the advancement of the baskets along the compartments 3 and 4 is kept strictly constant so as to ensure perfect alignment between the tubes 22 and the nozzles 32 every time the chains 6 and 7 stop.
A prerogative of the present invention is constituted by the fact that the tiles are subjected to a flow of air which is substantially constant in every point of the drying kiln, so as to ensure uniform drying of all the tiles.
According to the embodiment shown in figure 9, instead of the nozzles 32 there are openings 34 which extend vertically and are arranged oppositely at the ends of the tubes 22. The openings 34 are delimited laterally by gaskets 35 which are in sliding contact on the outer faces of the side walls 13 and 14 of the baskets in order to ensure connection between the chambers 24-27 and the tubes 22.
The described drying kiln is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

Vertical drying kiln for tiles, comprising a container (2) which is vertically divided so as to form two compartments (3, 4) which are mutually connected at the top and at the base, a pair of chains (6, 7) closed in a loop moving inside said compartments and supporting the baskets (8) which carry the tiles (19), characterized in that the baskets (8) have tubular elements (22) between the shelves (18) which support the tiles (19) and that inside said compartments (3, 4) there are chambers (24-27) connected to means (28-29) for feeding drying air and provided with holes (31; 34) which can be connected to said tubular elements (22), said tubular elements (22) being provided with openings (23) for expelling the drying air between said layers of tiles.
Drying kiln according to claim 1, characterized in that said tubular elements (22) are arranged so as to form horizontal layers which are arranged between the layers (18) of the tiles (19) and are aligned along vertical planes which are parallel to the ascending and descending portions of the chains (6, 7) for the conveyance of the baskets (8).
Drying kiln according to claim 1 or 2, characterized in that said chambers (24-27) extend inside the vertical compartments (3, 4) of the container (2) both along the ascending portion and along the descending portion of the chains (6, 7).
Drying kiln according to claim 3, characterized in that said chambers (24-27) are constituted by ducts which have a rectangular cross-section, channels (30) being formed in the faces of said ducts which are directed toward the baskets, in order to allow the passage of the chains (6, 7) for the conveyance of the baskets.
Drying kiln according to any of the preceding claims, characterized in that holes (31; 34) are formed on the faces of the chambers (24-27) which are directed toward the baskets (8), have the same distribution as said tubular elements (22), and are suitable to become aligned with said tubular elements while the baskets are not moving.
Drying kiln according to claim 5, characterized in that respective conical nozzles (32) extend from said holes (31) and produce a Venturi effect by aligning with the ends of said tubular elements (22).
Drying kiln according to any of claims 1 to 4, characterized in that vertical openings (34) are formed on the faces of the chambers (24-27) which are directed toward the baskets (8) and are surrounded by gaskets (35) which are in sliding contact on the side walls (13, 14) of the baskets (8).