Oven particularly for ceramic products

Abstract: An oven (1) particularly for ceramic products, comprising a chamber (3) made of refractory material which is mounted on a supporting framework (2) which forms at least two longitudinal parallel compartments (4) for the synchronous passage of at least two trolleys (5), each trolley being constituted by a front column (6) and by a rear column (7) provided with pairs of wheels (8); the columns pass through longitudinal slots (9) of the base (10) of the chamber (3) and have, at preset levels, a plurality of supporting means which are adapted to cooperate with the supporting means of the columns of the laterally adjacent trolleys in order to support, at at least four points, frames (12) for containing the ceramic products.

Description: The present invention relates to an oven particularly for ceramic products. It is known that many types of oven are used in the art, according to the conditions and reasons for which heating is performed. Depending on their operation, ovens are termed periodic when, after the transformation of the treated material has been completed, it is necessary to interrupt operation to change the load, and are termed continuous when the loading and unloading of the treated material occur without having to suspend the operation of the oven. As regards the ceramics sector, for example, kilns are known which are constituted by box-like structures made of refractory material which are closed on three sides and have moving bases on which frames with a plurality of shelves are mounted; the ceramic products to be treated are loaded onto said shelves. Once the moving bases have been loaded upstream of the kilns, they are arranged so as to close the box-like structures to allow treatment of the loaded products and are then sent to the stations for unloading the treated products, which are located downstream of the kilns. These kilns are not free from drawbacks, including the fact that they require considerable space upstream and downstream due to the bulk of the moving bases which support the frames with the corresponding and respectively untreated and treated products; that they require downtimes while waiting for the loading and unloading of the moving bases, with a consequent reduction in productivity; and that the heat absorbed by the walls and by the product during the treatment tends to be partly lost during the movement of the moving base, with a consequent waste of energy. A Kiln in which Kiln cars are guidingly movable is Known from the document WO 97/27440. The aim of the present invention is to eliminate the above-mentioned drawbacks of conventional ovens, providing an oven particularly for ceramic products which allows to improve energy efficiency by reducing thermal inertia and heat losses, minimizes the dimensions and the space required for the transport of the products entering and leaving said oven, and fully eliminates waiting periods due to the loading and unloading of the ceramic products. Within the scope of this aim, an object of the present invention is to provide a structure which is simple, relatively easy to provide in practice, safe in use, effective in operation, and having a relatively low cost. This aim and this object are both achieved by the oven according to the present invention, particularly for ceramic products, which has the features set forth in claim 1. Further characteristics and advantages of the present invention will become apparent from the detailed description of a preferred but not exclusive embodiment of an oven particularly for ceramic products according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a schematic and partially sectional front view of an oven particularly for ceramic products according to the invention; Figure 2 is an enlarged-scale sectional front view of a detail of a trolley of the oven of Figure 1; Figure 3 is a schematic top view of another embodiment of a ceramic product containment frame of an oven according to the invention; Figure 4 is a schematic side view of two successive trolleys of the oven according to the invention. With reference to the above Figures, the reference numeral 1 generally designates an oven particularly for ceramic products according to the invention. The oven 1 is constituted by a framework 2 for supporting a chamber 3 made of refractory material. The framework 2 forms two longitudinal and parallel compartments 4 whose dimensions allow the synchronous passage of two mutually laterally adjacent trolleys 5. The trolleys travel together in a longitudinal direction with respect to the oven 1, and belong to corresponding series of trolleys 5 which are mutually aligned and upstream of which there is a pusher which allows the continuous advancement of the pairs of mutually laterally adjacent trolleys. Each trolley is constituted by a front column 6 and by a rear column 7 which are provided with pairs of wheels 8. The columns of each trolley 5 pass through respective longitudinal slots 9 which are formed in the base 10 of the chamber 3 and have, at preset levels, a plurality of supporting means constituted by brackets 11. The brackets 11 of the columns 6 and 7 of a carriage 5 that are arranged at the same level cooperate with the corresponding brackets of the laterally adjacent trolley, so as to support in at least four points a frame 12 on which the ceramic products, not shown, are contained. As an alternative to the brackets 11, the columns can have supporting means constituted by notches, indents or the like which are adapted to support the corresponding frames 12. The frames 12 can be large and have a plurality of transverse elements 12a and longitudinal elements 12b which are mutually rigidly coupled and rest on the corresponding brackets 11 of the trolleys 5. The front column 6 of each trolley 5 is connected to the rear column 7 by means of a longitudinal member 13 whose cross-section is complementary to the cross-section of the slot 9 that it crosses, so as to reduce heat loss toward the outside of the chamber 3. The front end 14 of the longitudinal member 13 is shaped so as to mate with the rear end 15 of the longitudinal member 13 of the next trolley 5. Below the chamber 3, at the slots 9 of the base 10, the supporting framework 2 is provided with two longitudinal profiled elements 16, each of which cooperates with a corresponding profiled element 17 which is rigidly coupled to each trolley 5. The profiled elements 16 and 17 have a substantially comb-like cross-section, so as to provide labyrinth seals 18 which prevent outward dissipation of heat and ensure improved energy efficiency. The labyrinth seals 18 are in fact pressurized with externally arranged ventilation means and their pressure is regulated by means of pressure transducers as a function of the internal pressure of the oven 1. The framework 2 comprises a plurality of cross-members 19 and uprights 20, and two pairs of rails 21 are fixed on the cross-members 19a arranged at the base; the pairs of wheels 8 of the trolleys 5 run on said rails. Conveniently, the rails 21 are of the type with movable anchoring and allow to absorb any movements caused by thermal expansion. The columns 6 and 7 are mounted so that they can rotate in their respective trolleys 5 and there are rotation means, not shown in the various Figures, which allow a planar rotation of said columns through at least 90 degrees, so as to laterally remove the brackets 11 and allow to lift the various frames 12 and extract them from above. At the inlet and outlet of the oven 1 there are loading and unloading stations at which said column rotation means are present. In the loading station, the frames 12 are arranged on the trolleys 5, while in the unloading station the frames 12 are lifted and then picked up by an independent unit which collects them and transfers them all together to the loading/unloading of the ceramic products. It has thus been observed that the invention achieves the intended aim and object, i.e. provides increased productivity by reducing downtimes, optimizes the space required for the transport, loading and unloading of the ceramic products, and improves the energy efficiency of the oven. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. All the details may furthermore be replaced with other technically equivalent ones. In practice, the materials used, as well as the shapes and the dimensions, may be any according to the requirements without thereby abandoning the scope of the protection of the claims that follow. The contents of Italian patent application no. MO98A000026, whose priority is claimed in the present application, are included as reference: 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 interpretation of each element identified by way of example by such reference signs.

Claims: An oven, particularly for ceramic products, comprising: a chamber made of refractory material (3); at least two trolleys (5); a supporting framework (2) on which said chamber (3) is mounted, said chamber (3) having a base (10) which forms at least two longitudinal parallel guiding slots (9), each said trolley (5) being constituted by a front column (6) and by a rear column (7) provided with pairs of wheels (8), said columns (6, 7) being adapted to pass through said longitudinal slots (9) whereby to allow the synchronous guided passage of said trolleys (5) through said chamber (3); supporting means (11) provided at said columns (6, 7) at preset levels; frames (12) for containing the ceramic products, said supporting means (11) being adapted to cooperate with the supporting means (11) of the columns (6, 7) of the laterally adjacent. trolleys (5) in order to support, at at least four points, said frames (12); and labyrinth seals (18) for preventing heat dissipation outside of said chamber (3), characterized in that said supporting framework (2) forms, under said base (10), two longitudinal parallel compartments (4), said labyrinth seals (18) being accommodated in said compartments (4), arranged under said base (10) at said slots (9). The oven according to claim 1, characterized in that said supporting means are constituted by brackets (11). The oven according to claim 1, characterized in that said front column (6) and said rear column (7) of each trolley (5) are mutually connected by a longitudinal member (13) whose cross-section is complementary to the cross-section of said slot (9). The oven according to claim 3, characterized in that the cross-section of said longitudinal member (13) is substantially trapezoidal. The oven according to one or more of the preceding claims, characterized in that the front end (14) of said longitudinal member (13) is shaped so as to mate with the rear end (15) of the longitudinal member (13) of the trolley (5) that follows. The oven according to one or more of the preceding claims, characterized in that said supporting frame (2) has, below said slots (9) of the base (10) of the chamber (3), two longitudinal profiled elements (16) which have a substantially comb-like cross-section and are adapted to cooperate with corresponding profiled elements (17), which have a substantially comb-like cross-section and are rigidly coupled to the trolleys (5), in order to form said labyrinth seals (18). The oven according to one or more of the preceding claims, characterized in that at least two pairs of rails (21) for said trolleys (5) are fixed to the cross-members (19, 19a) of the base of said framework (2). The oven according to one or more of the preceding claims, characterized in that said columns (6, 7) are mounted so that they can rotate in the respective trolleys (5) and in that rotation means for turning the columns (6, 7) through at least ninety degrees are further provided in order to remove said brackets (11) laterally and to allow lifting of the frames (12) and/or extraction thereof in an upward direction. The oven according to one or more of the preceding claims, characterized in that at the inlet and at the outlet of the oven (1) loading and unloading stations are arranged at which said column rotation means are provided. The oven according to claim 1, characterized in that said supporting means (11) are constituted by notches, indents or the like. The oven of claims 1 or 6, characterized in that said labyrinth seals (18) are pressurized, pressure generation and regulation means being further provided for regulating the pressure at said labyrinth seals as a function of the internal pressure of the oven (1). The oven of claim 11, characterized in that said pressure generation and regulation means are constituted by external ventilation means and by pressure transducers.

Inventors: MARCACCIOLI SERGIO, INTECO CERAMIC SUPPLIES S.R.L., MARCACCIOLI, SERGIO
Applicants: MARCACCIOLI SERGIO, MARCACCIOLI, SERGIO
Application year: 1999
Main classification: F27B9
IPC codes: F27D5, F27B9, F27D23