BRPI0620969A2 - process for retroactive management and regulation of a tunnel oven and apparatus for retroactive management of a tunnel oven - Google Patents

Abstract

PROCESS FOR RETROACTIVE MANAGEMENT AND REGULATION OF A TUNNEL OVEN AND APPLIANCE FOR RETROACTIVE MANAGEMENT OF A TUNNEL OVEN. A process for the management and retroactive regulation of a tunnel kiln for cooking ceramic tiles, comprising burners located above the roller plane and below the roller plane, nozzles delivering forced cold air to a terminal part of the oven, and devices to detect a internal oven temperature, controlled by a processor, comprises the following operations: adjusting the processor to a desired temperature curve; memorize in a first memory standard defects related to the shape and dimension of the tiles, memorize in a second memory, for each of the standard defects, modifications for the management of the oven in order to reduce defects; carry out intervals on each tile of the same transversal alignment of the tiles leaving the oven to control their planarity and dimensions in order to determine a type of defect detected by comparison with data contained in the first memory; and point out the defect detected to the processor, which identifies the defect by comparing it with the data contained in the first memory and mediating the supply to the burners and cooling air nozzles based on the data indications contained in the second memory.

Description

"PROCESS FOR MANAGEMENT AND RETROACTIVE REGULATION OF A TUNNEL OVEN AND APPARATUS FOR RETROACTIVE MANAGEMENT OF A TUNNEL"

Technical Field

The invention relates to ceramic tile ovens, and more specifically to the quality control of their products.

Fundamentals of Art

Success during the tile baking stage in kilns known as tunnel kilns depends almost exclusively on observing the longitudinal temperature curve maintained within the kiln throughout its longitudinal section.

In this context, the term longitudinal curve means the temperature curve in the direction of material advance, that is, in a direction parallel to the geometrical axis of the furnace.

The ovens referred to comprise a material conveyor roller plane located in a tunnel structure having sidewalls as well as two series of burners directed towards the center of the furnace and located on the sidewalls throughout the entire length of the furnace. furnace, a trailing line aligned above the roller plane, and another trailing line aligned below the roller plane, where the burners of each series comprise first burners, known as radial burners, predominantly for heating the areas near the alternating sidewalls. with second burners, known as axial burners, to predominantly heat the central zones of the furnace.

At the furnace end, near the outlet of the material, rapid cooling devices are provided, comprising varied fashion oriented nozzles that deliver pressurized cold air generated by pressurized air generating devices such as axial or radial fans.

All product quality parameters depend on the longitudinal temperature curve, such as the flat condition of the tiles when leaving the oven and the regularity of the tile dimensions.

The prior art describes processes that enable the longitudinal temperature curve to be kept constant automatically, even in the presence of load discontinuity, in order to maintain product quality within commercially acceptable limits.

The prior art processes retroactively intervene on the temperature curve acting on the burners that heat the oven; that is, they intervene in dealing with the oven that heats the tiles by encountering a defect in the product that comes out of the oven.

Known processes have provided some results in eliminating dimensional defects, although they have been shown to be inadequate in connection with planar condition defects.

Known processes have also been shown to have limits on dimensional defects due to the increased transverse dimensions of the furnace.

The aim of the present invention is to provide a method and apparatus for retroactively controlling a product quality chord tunnel oven as verified upon leaving the oven.

Although it has been observed that, to eliminate dimensional defects, temperature control above and below the furnace roller plane yields some positive results, such positive results were not observed with respect to planarity.

This is attributable to the fact that the tile, thanks to its flatness at high baking temperatures, has a tendency to relax on the roll plane due to its own weight, with the result that it is not very sensitive to the above temperature differences. and below the roller plane The tile tends to shrink, increasingly fashionable as the furnace temperature rises, this construction is due to gas development and interstitial closure during partial sintering, and temperature control in the cross section of the furnace. The furnace offers good results in keeping the tile dimensions at a commercially acceptable level, even in close proximity to the furnace walls.

The flatness defects revealed at the furnace outlet also occur predominantly in the rapid cooling zone, and can be attributed to a differentiated dimensional decrease of the material in the tile parts that are close to its upper surface and lower surface.

The higher the coefficient of thermal expansion of the material in the aforementioned parts, the greater the dimensional decrease during cooling.

The invention therefore intervenes on the coefficient of expansion of the material to have an effect on planarity.

The coefficient of expansion of materials with a vitreous component, such as ceramic tile material, increases considerably as the cooling rate decreases.

Accordingly, the invention teaches the intervention on the cooling rate during the rapid cooling process, but unlike the upper surface and the lower surface of the tile.

This enables the invention to achieve its objectives thanks to the combination of features as enumerated in independent process claim 1 and the independent apparatus of claim 35.

The subordinate claims relate to advantageous embodiments of the invention.

Description of the Invention

Substantially, the process of the invention includes experimentally determining the ideal longitudinal curve of the temperature CT0 of heating according to the material used and also according to the dimensions and quality of the tiles in each batch to be baked.

According to the aforementioned curve, at the beginning of the batch batch cooking operations, the oven thermal plants are adjusted with respect to both heating and cooling functions.

Through the entire firing of the material, the following are monitored inside the oven at a distinct series of significant points: the Tist temperature on the oven geometry axis and preferably at least one parallel geometry axis near one of the side walls, both above as below the rollers plane.

In various furnace sections, deviations Δτ from the monitored temperature Tist of the stored ideal curve TC0 are stored and transmitted to the processor controlling the furnace, which performs a first correction of the thermal plants in order to keep the values within an acceptable field.

At predetermined intervals at the furnace outlet, planarity and dimension controls are performed on each tile of the tiles exiting in the same transverse group alignment.

More specifically, first devices for controlling planarity and second devices for controlling dimensions are foreseen.

The detected data is compared with standard data stored in memory typical of each product type, and when the comparison shows a deviation from a predefined range, the deviation type is flagged for a processor that on its own program then modifies the power supply. for burners and devices for generating cooling air that are influencing bypass.

More specifically, the processor is provided with at least a first memory containing the most common standard defects in tiles, statistically detected; a second memory containing commentary and cooling temperature corrections to reduce any type of defect; and a program for correlating defects found with those stored in the first memory, and for rapidly controlling the burners and devices for generating pressurized air to achieve an adequate reduction in the detected defect, according to the data contained in the second memory.

The apparatus of the invention comprises all the devices necessary to promote the activities that make up the process.

Brief Description of the Drawings

The correlation between the standard defects of the shingles after firing and the modifications to be made to the heating curves will be more clearly apparent from the following examples, which are illustrated by way of non-limiting example in the accompanying drawings in accordance with the which are:

Figure 1 is a plan view of the furnace plane with the burners and cooling air generating devices located above the roller plane;

Figure 2 is a plan view of the furnace plane with the burners and cooling air generating devices located below the roller plane.

Ideal Modality for Carrying Out the Invention

The figures of the drawings show the oven roller plane, indicated at 15 over which the tiles spread from right to left in the figures.

Both above and below the roller plane are known type and axial type 2, 20, 3 and 30 burners, which predominate to heat the central zones of the furnace, and known radial type burners 4, 40, predominantly to heat the areas near the oven walls.

The burners are positioned facing the side walls of the furnace, and the burners on one wall are staggered with respect to the burners on the opposite wall. Axial type burners 2, 20 near the oven inlet are for preheating the tiles, while burners 3, 30, 4 and 40 for heating the tiles.

Rapid cooling of the tiles begins downstream of the burners 4, 40, with a cold air injection (at room temperature) through nozzles confronting the roll plane and arranged on two upper transverse manifolds 5 and 6, on two lower manifolds 50 and 60, as well as on two longitudinal collectors 70 parallel to the geometrical axis of the furnace and arranged below the plane of the rollers.

Each of the collectors preferably are connected with air generating devices which are independent of the devices for generating the other collectors.

Burners 2, 20, 3, 30, 4, and 40 are connected individually or in pairs with the central processor P (not shown) which governs the furnace and controls the supply of fuel and combustion air to each of them.

The devices for generating air from manifolds 5, 50, 6, 60 and 70 are individually connected with the same processor P which also governs their operating pressure.

The temperature sensors 11 and 11a within the furnace are located above the roller plane, respectively in the center and near their walls.

The oven temperature sensors 110 and 11 Oa are located below the roller plane, respectively in the center and near their walls. The transverse lines of the tiles upon leaving the furnace are transferred in succession over a conveyor 8 having a geometrical axis that is perpendicular to the furnace geometric axis, on which a single line of tiles 81 is formed.

The first planarity control devices 10 are located above the conveyor 8, and the second dimension control devices, which are of known type, are also located above the conveyor 8, and are also connected with the central processor P to which signal each defect found.

The standard defects found in processor memory, and relative remedies, are as follows:

A large or small caliber

This occurs when the dimensions of the part are larger or smaller than required. It is connected by increasing or respectively reducing the flame temperature of burners 3, 30, 4 and 40 from 1 ° C to 5 ° C both above and below the roll plane.

The increase in flame temperature causes a reduction in part size.

B. Long Side Trapezoid Effect Near Walls

This defect is corrected by increasing the flame temperature in radial burners 4, 40 both above and below the plane of the rollers.

C. Short side trapezoid effect near walls

This defect is corrected by reducing the flame temperature in burners 4, 40.

D. Homogeneous concave side - upward-facing concavity

This defect is corrected by an intervention in the rapid cooling zone. In manifolds 5 and / or 6. The flame temperature of burner burners 30 and 40 below the roller plane is synergistically increased while the flame temperature of burners 3 and 4 above the roller plane is reduced. in the final cooking zone.

E. Concave profile in planes that are perpendicular to the rollers

This defect is corrected in different ways according to the material. For single-fired white and red tiles and glazed clay tiles, the flame temperature of the burners 20 and 30 below the roller plane is reduced in the pre-baking and initial cooking zone while the flame temperature of burners 2 and 3 above the roller plane is increased. Synergistically, at the onset of the rapid cooling zone, the pressure in manifold 50 and / or 60 below the roller plane is reduced, and the pressure in manifold 5 and / or 6 above the roller plane is increased.

For monoporous or double-fired screens, in the final heating zone burner 3 and 4 (above the roller plane) flame temperatures are reduced, while in burners 30 and 40 (below the roller plane) flame temperatures are reduced. increased by the same amount.

Synergistically, manifold pressures 50 and / or 60 at the start of the rapid cooling zone are reduced from below, and manifold pressures 5 and / or 6 are increased from above.

F. Concave profile in planes that are parallel to the rollers

This defect is corrected by intervening differently according to the materials. For monocozed red and bunker tiles and glazed clay tiles, the manifold 50 and / or 60 the pressure is reduced (from below) and the collector pressure 5 and / or 6 (from above) is increased by the same value. .

For monoporous and double fired tiles, the flame temperature of the preheat burner 20 is reduced (below the roller plane) and the burner flame 2 (above the roller plane) is increased by the same value. Synergistically, at the beginning of the rapid cooling zone the pressure in manifolds 50 and / or 60 is increased (from below) while the pressure in manifolds 5 and / or (from above) is increased by the same value.

G. Convex homogeneous profile - downward-facing concavity

This defect is corrected by intervening differently according to the materials used.

For white and red single-baking tiles and glazed clay tiles, at the beginning of the rapid cooling zone the pressure is increased at the 50 and / or 60 manifolds from below, and the pressure at the 5 and / or 6 manifolds. from above it is decreased by the same value.

Synergistically, in the extreme cooking zone the flame temperatures of burners 30 and 40 are reduced below the roller plane and the flame temperatures of burners 3 and 4 above the roller plane are increased by the same value. Moreover, and also synergistically, in the initial cooking zone the flame temperatures of the burners 30 below the roller plane are increased and the flame temperatures of the burners 3 above the roller plane are reduced by the same value.

For monoporous and double baking tiles, the temperature of the burner 3 above the roll plane is reduced at the beginning of the cooking zone, while the temperature of the burner 3 and 4 is increased at the end of the cooking zone.

Below the roller plane, the temperatures of the burners 30 are increased at the start of the roller plane (initial cooking zone) and temperatures of the burners 30 and 40 are reduced at the end of the roller plane (final heating zone). At the beginning of the rapid cooling zone the pressure in manifolds 50 and / or 60 (from below) is increased, while synergistically the pressure in manifolds 5 and / or 6 (from above) is reduced.

Η Convex profile in planes that are perpendicular to the rollers.

To reduce this defect the flame temperature of burners 20 and 30 is increased in the pre-cooking zone and initial heating zone below the roller plane, while the temperature of burners 2 and 3 above the roller plane is decreased.

Synergistically, the pressure in manifold 50 and / or 60 below the roller plane is increased and the pressure in manifold 5 and / or 6 above the roller plane is reduced.

I. Convex profile in planes that are parallel to the rollers

This defect is corrected in different ways according to the type of materials. For single-fired white and red tiles and glassy tiles, at the beginning of the rapid cooling zone the pressure is increased at manifolds 50 and / or 60 from below and the pressure at manifolds 5 and / or 6 from below. from above it is decreased by the same value.

For monoporous and double fired tiles, in the pre-firing zone the temperature of the burner flame 2 is reduced (above the roller plane) and the burner flame 20 (below the roller plane) is increased by the same value.

At the beginning of the rapid cooling zone the pressure in manifolds 50 and / or 60 (from below) is increased, while synergistically the pressure in manifolds 5 and / u 6 (from above) is reduced by the same value.

L. Convex profile of parts when outside the oven.

When convexity is limited to parts near the furnace walls at the beginning of the rapid cooling zone, the pressure in manifolds 70 is increased. Adjustments of temperatures and pressures, either up or down, are preferably in each case the same amount, or multiples thereof, so that after a small number of repeated interventions, the oven setting stabilizes at the desired levels and the Produced tile falls within a commercially acceptable quality range.

Claims (38)

A process for retroactively managing and regulating a tunnel kiln for baking ceramic tiles, comprising a roller conveyor plane, a series of burners located above the roller plane, a series of burners located below the plane. a series of manifolds provided with nozzles forcing forced cold air into an end portion of the furnace, the nozzles of which are located both above and below the roller plane, devices for detecting a temperature inside the furnace as well as a processor for control the fuel and air supply to the burners individually and in pairs and to control an air pressure circulating inside the collectors in order to maintain a temperature curve of the detected temperatures at preset levels, characterized by the fact that it comprises The following operations: For each batch of tiles to be baked, adjust the processor to a the desired temperature curve; in a first processor memory, memorize standard defects related to the profile and dimensions of the tiles; in a second processor memory, for each of the standard defects to introduce modifications either to increase or decrease burner flame temperatures and / or cooling air pressure to values that will reduce the defects; at the furnace exit, on each tile of the same alignment of tiles leaving the furnace, perform a control of their planarity and dimensions at intervals to determine a type of defect detected by comparison with standard defect data contained in the first memory. ; flag the defect detected for the processor, which identifies the defect by comparing it with the data contained in the first memory and modifying the supply to the burners and / or the cooling air nozzles, the cooling speed being adjusted differently on the upper side. bottom of the tile in such a way as to act upon the defect detected based on data indications contained in the second memory, and based on a processor program. Process according to Claim 1, characterized in that the standard defects in tile dimensions that are stored in the first memory are as follows: caliber, trapezoidal effect with continuous longitudinal side of the walls, trapezoidal effect with short side near the walls. Process according to Claim 1, characterized in that the standard profile defects memorized in the first memory are as follows: concave and convex homogeneous profile; concave and convexity in planes parallel to the rollers; concave and convexity in planes perpendicular to the rollers; connection of adjacent parts to the walls. Process according to claim 1, characterized in that the control of the planarity of the tiles of each alignment is performed simultaneously on all tiles in the alignment. Process according to claim 1, characterized in that the control of the planarity of the tiles of each alignment is performed simultaneously on all tiles in the alignment. Process according to claim 1, characterized in that the control of the tile dimensions of each alignment is carried out simultaneously over all tiles in the alignment. Process according to claim 1, characterized in that the control of the tile dimensions of each alignment is carried out in succession over all tiles in the alignment. Process according to claim 1, characterized in that in order to correct dimensional defects of gauge with part dimensions that are larger than the desired part dimensions, the second memory comprises following instructions to be transmitted to the processor; Increase the cooking temperature from 1 ° C to 50 ° C above and below the roller plane. Process according to claim 1, characterized in that in order to correct dimensional defects of gauge with part dimensions that are smaller than the desired part dimensions, the second memory comprises following instructions to be transmitted to the processor; Increase the cooking temperature from 1 ° C to 50 ° C above and below the roller plane. Process according to claim 1, characterized in that in order to correct dimensional defects with trapezoidal effect on a long side with you to the wall, the second memory comprises following instructions to be transmitted to the processor: increasing the flame temperature of the radial burners 4, 40 at the end of the heating zone. Process according to Claim 1, characterized in that in order to correct trapezoidal dimensional defects on a short side contiguous to the wall, the second memory comprises according to instructions to be transmitted to the processor to reduce the flame temperature of the radial burners. 4, 40 at the end of the heating zone. Process according to Claim 1, characterized in that in order to correct homogeneous concavity - upwardly concavity planarity defects, the second memory comprises following instructions to be transmitted to the processor: reducing the cooling air pressure in the manifolds 50 and 60 located below the roller plane, and increase pressure at manifolds 5 and / or 6 above the roller plane. Process according to claim 12, characterized in that the second memory comprises additional instructions to be transmitted to the processor, as follows: increasing the flame temperature of burners 30 and 40 located below the roller plane and reducing the temperature of burners 3 and 4 located above the roller plane at the end of the heating zone. Process according to claim 1, characterized in that in order to correct the concave polarity defect in the planes which are perpendicular to the white and red single-baking tile rolls and glazed tiles, the second memory comprises instructions to be transmitted to the processor as follows: reduce the flame temperature of burners 20 and 30 below the roll cloth in the pre-cooking zone and the initial cooking zone and raise the temperatures of burners 2 and 3. Process according to claim 14, characterized in that the second memory comprises additional instructions to be transmitted to the processor as follows: reducing the pressure in the manifold 50 and / or 60 below the roll plane at the beginning of the zone cooling, and increase manifold pressure 5 and / or 6 above the roller plane. Process according to claim 1, characterized in that in order to correct the concave planarity defect in planes which are perpendicular to the monoporous ceramic tiles or double-baked tiles rolls the second memory comprises instructions as follows to be transmitted to the processor: reducing the flame temperature of burners 30 and 40 below the roller plane in the extreme cooking zone and increasing the flame temperatures of burners 3 and 4 above the roller cloth in the final heating zone by the same amount. Process according to claim 16, characterized in that the second memory comprises additional instructions to be transmitted to the processor as follows: reducing the pressure in the manifolds 50 and / or 60 from below and increasing by the same value the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone. Process according to claim 1, characterized in that in order to correct the concavity planarity defect in planes parallel to the roll for single white and red baking tiles and glazed ceramic tile, the second memory comprises instructions to be transmitted. for the processor as follows: reduce the pressure in manifolds 50 and 60 from below and increase the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone by the same amount. Process according to claim 1, characterized in that in order to correct the concave planarity defect in planes parallel to the roll for monoporous ceramic tiles or double-baking tiles, the second memory comprises instructions to be transmitted to the processor. as follows: reducing the flame temperature of the burners 20 below the roller plane in the preheating zone and increasing the flame temperatures of the burners 2 above the roller plane by the same amount. Process according to claim 19, characterized in that the second memory comprises additional instructions to be transmitted to the processor as follows: reducing the pressure in the manifolds 5 and / or 6 from above in the start zone fast cooling. Process according to claim 1, characterized in that in order to correct the homogeneous convexity planarity defect with downwardly directed concave for white and red single-baking tiles and glazed ceramic tiles, the second memory comprises instructions to be transmitted to the processor as follows: increasing the pressure in the manifolds 50 and / or 60 from below and reducing by the same amount the pressure in the manifolds 5 and / or 6 from above in the rapid cooling start zone. Process according to Claim 21, characterized in that the second memory comprises additional instructions to be transmitted to the processor as follows: reducing the flame temperature of the burners 30 and 40 below the plane of the rolls in the cooking zones and increasing the flame temperature of the burners 3 and 4 above the roller plane by the same amount. Process according to Claim 22, characterized in that the second memory comprises additional instructions to be transmitted to the processor, as follows: increasing the flame temperature of the burners 30 below the roller plane and reducing by the same value. the flame temperatures of the burners 3 above the roller plane. Process according to claim 1, characterized in that in order to correct the homogeneous convexity planarity defect with downwardly directed monoporous ceramic tile or double baking tiles, the second memory comprises instructions to be transmitted to the processor as follows: increasing the flame temperature of the burners 30 below the roller plane and reducing the flame temperatures of the burners 3 above the roller plane by the same amount. Method according to Claim 24, characterized in that the second memory comprises additional instructions to be transmitted to the processor, as follows: increasing the pressure in the manifolds 50 and / or 60 from below and reducing it by the same. value the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone. Process according to claim 1, characterized in that in order to correct the convexity defect in the planes that are perpendicular to the rollers, the second memory comprises instructions to be transmitted to the processor as follows: increasing the flame temperature of the burners 20 and 30 below the roller plane and reduce the flame temperatures of burners 2 and 3 above the roller plane by the same amount in the pre-cooking and initial cooking zones. A method according to claim 26, characterized in that the second memory comprises additional instructions to be transmitted to the processor, as follows: increasing pressure in manifolds 50 and / or 60 from below and reducing by the same value. the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone. Process according to claim 1, characterized in that in order to correct the convexity planarity defect in the planes which are perpendicular to the rolls for white and red single-baking tiles and glazed ceramic tiles, the second memory comprises instructions to be transmitted to the processor as follows: increase the pressure in manifolds 50 and / or from below and reduce the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone by the same amount. Process according to claim 1, characterized in that in order to correct the convexity defect in the planes which are parallel to the white and red single-baking tile rolls and glazed ceramic tiles, the second memory comprises instructions to be transmitted to the processor as follows: increasing pressure in manifolds 50 and / or 60 from below and reducing the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone by the same amount. The method according to claim 1, characterized in that in order to correct the flatness convexity defect in the planes which are parallel to the monoporous ceramic tile or double baking tile rolls, the second memory comprises instructions to be transmitted to The processor is as follows: reducing the flame temperature of the burners 2 above the roller plane in the pre-cooking zones and increasing the flame temperatures of the burners 20 below the roller plane by the same amount. Process according to claim 30, characterized in that the second memory comprises additional instructions to be transmitted to the processor, as follows: increasing the pressure in the manifolds 50 and / or 60 from below and reducing by the same one. value the pressure in manifolds 5 and / or 6 from above in the rapid cooling start zone. Method according to claim 1, characterized in that in order to correct the convexity planarity defect in the wall adjoining parts, the second memory comprises instructions to be transmitted to the processor as follows: increased pressure in the longitudinal collectors 70 . Process according to claim 1, characterized in that the changes in raising and lowering temperatures and pressures are of the same amount in all interventions, so that after a small number of repeated interventions an oven setting stabilizes to the desired values and the tiles produced fall within a commercially acceptable quality standard. The method according to claim 33, characterized in that the changes in raising and lowering temperatures and pressures are in all interventions a multiple of the same amount. 35. An apparatus for retroactively managing a ceramic tile tunnel kiln comprising: - a plane of rollers for conveying material located in a tunnel structure provided with side walls, in which are located: - two series of burners, respectively a series above and a series below the roller plane, whose burners are directed towards an oven center and whose burners are distributed along an extension of the oven. - two series of manifolds, respectively above and below the roller plane, whose manifolds are provided with nozzles for directing cold air in the direction of the roller plane, whose manifolds are located in an oven end zone, from whose end end the material flows. ; devices for generating pressurized air being associated with the manifolds. - devices for controlling a temperature distributed over the entire length of the oven; a processor for controlling the operation of burners according to signals transmitted by temperature sensing devices; characterized by the fact that it comprises: - first devices for controlling the flatness of the tiles when leaving the oven. - second devices for controlling the dimensions of the tiles coming out of the oven; the processor being predisposed to receive signals from first and second devices, and comprising - a first memory in which standard defects of tile size and planarity are stored; and a second memory containing instructions to be transmitted to the burners and devices for generating pressurized air in order to reduce each of the memorized standard defects; a unit of calculation which, according to the data received from the first and second devices and the data contained in the first and second memories, commands an operation of the individual burners and individual pressurized air generators to adjust the cooling rate differently on the side. top and bottom of the tile. Apparatus according to claim 35, characterized in that each manifold is provided with a device for generating cooling air. Apparatus according to claim 35, characterized in that a conveyor is located at the exit of the furnace, which conveyor has an axis that is perpendicular to an axis of the furnace, with whose conveyor axis the tiles are aligned when exiting the furnace. kiln and above which the first and second devices for controlling the planarity and dimensions of the tiles are located. Apparatus according to claim 35, characterized in that it comprises temperature sensing devices located in close proximity to the oven sidewall surfaces.