IT202100011840A1 - DEVICE FOR CONTROLLING THE OUTPUT OF GLAZE FROM A VELATURA HEAD - Google Patents

Description

DEVICE FOR CONTROLLING THE OUTLET OF ENAMEL FROM A VELATURA HEAD

DESCRIPTION OF THE INVENTION

The present invention belongs to the technical sector concerning the machinery used in the ceramic industry for the decoration of ceramic tiles or slabs.

In particular, the machines which apply a uniform layer of liquid glaze on the entire facade, or on a part of it, of said ceramic tiles or slabs are taken into consideration, said machines being also known as glazing heads, for the experts of the sector.

A veiling warhead ? essentially consisting of a hopper into which the liquid glaze is fed, preferably of the so-called "solution" type, affected at the bottom by a calibrated outlet slot, from which a blade of said liquid glaze emerges which, by falling, is deposited on the underlying ceramic tiles or slabs in transit, arranged in orderly succession and advanced, with speed? constant, from a straight line of transport.

As a rule, in the transport line, ? there is an empty space between one ceramic tile or slab and another, obviously intended to pass under the glaze head as well, therefore the liquid glaze dispensed in the time interval in which the passage of said empty space is completed is wasted and falls into an underlying collection tank.

According to the known technique, at least part of the glaze recovered in the collection tank can be recycled in production, but for this it must be duly filtered to eliminate any impurities? and sometimes even corrected to restore the right chromatic gradation.

? intuitive to understand how such a method of proceeding represents a considerable increase in production costs, due to a large quantity of wasted liquid enamel.

Furthermore, the liquid enamel that is not deposited on the tiles gets dirty on the conveyor line as well as on the tiles. all the organs used for its recovery, making it necessary to prepare periodic washing operations, with consequent downtime.

Another inconvenience that arises concerns the fact that the recovery enamel which is not? possible to recycle must be rendered harmless to? environment, before being disposed of, with the costs that there? leads.

The purpose of the present invention ? why? that of proposing a device for the intermittent opening of the liquid ceramic glaze outlet from a glazing head, designed in such a way as to stop the delivery of said liquid ceramic glaze whenever the empty space between the a ceramic tile or slab and the subsequent carried by the conveyor line.

Another object of the invention consists in equipping the device with the necessary operating parts suitable for obtaining the correct phase synchronization between the stop and the resumption of the dispensing of liquid ceramic glaze with the beginning and the end of the passage of each empty space.

Another object of the invention is to provide a device which has active control systems capable of intervening in real time on the parameters relating to said phase synchronization, in the presence of speed variations. of the conveyor line and/or differences in length between one of said empty spaces and the others, to avoid production waste on the ceramic tiles or slabs.

A further object of the invention foresees that the task of arresting the descent of the liquid ceramic glaze is performed by means of members external to the glazing head, capable of acting very quickly both in closing and in opening, guaranteeing certain and reliable operation in the time.

Yet another purpose of the invention? that of proposing a device that can be applied to the heads of glazes without modifications to the structural parts of the latter.

These and other objects are fully achieved by means of a device for the intermittent opening of the liquid ceramic glaze outlet from a glazing head, with the latter arranged above a rectilinear conveying line on which they advance at high speed. constant ceramic tiles or slabs arranged in orderly succession, in which ? an empty space is provided between each of said ceramic tiles or slabs and the next, with the same glazing head essentially consisting of a hopper affected at the bottom by a calibrated exit slit, from which a blade of said liquid ceramic glaze emerges intended to uniformly cover a part or the entire upper face of said ceramic tiles or slabs, with the aforesaid device comprising:

-? first means for feeding said liquid ceramic glaze into the aforementioned hopper, in quantities exceeding the consumption of the same liquid ceramic glaze as a consequence of its leakage from said calibrated outlet slot;

-? second means for extracting said excess liquid ceramic glaze from inside said hopper, and for recirculating at least part of the recovered liquid ceramic glaze;

-? members for regulating the pressure inside said hopper, associated with said first and second means;

-? control and command members, associated with said members for regulating the internal pressure of the hopper and provided for selectively actuating the same so as to determine: a working condition of the device, in which the internal pressure of the hopper ? maintained equal to or greater than the external atmospheric one, cos? to allow the regular descent of said liquid ceramic glaze towards said calibrated outlet slot, in phase relationship with the passage, below the latter, of one of said ceramic tiles or slabs; a block condition of the device, in which the internal pressure of the hopper ? maintained, however, less than the external atmospheric one, cos? to stop the descent of said liquid ceramic glaze, interrupting its delivery, in the time interval necessary for the passage of each of said empty spaces.

The characteristics of the invention in question will become evident from the following description of preferred embodiments of the device for the intermittent opening of the liquid ceramic glaze outlet from a glazing head, referred to in the subject, in accordance with what is proposed in the claims and with the help of the attached drawing tables, in which:

-? Fig. 1 is a schematic side view of a portion of a conveyor line for ceramic tiles or slabs, and a glazing head;

-? Fig. 2 illustrates, in plan view, the portion of the conveying line and the veiling head of Fig.1;

-? Fig. 3 illustrates, in a schematic view, a first embodiment of the device in question;

-? Fig. 4 illustrates, in a schematic view similar to Fig. 3, a second embodiment of the device in question;

-? Figs. 5, 6, 7, 8 illustrate as many schematic views relating to successive operating moments of the device.

In the above figures, ? the device object of the present invention, as a whole, has been indicated with reference 1.

Device 1? associated with a known sailing head 2, arranged above a rectilinear transport line 3 on which they advance with speed? constant V ceramic tiles or slabs 4 arranged in orderly succession, spaced one from the other by an empty space 5.

The fogging head 2, according to the prior art, is essentially consisting of a hopper 20 affected at the bottom by a calibrated outlet slit 21, from which a blade of liquid ceramic enamel S emerges intended to uniformly cover a part or, preferably, the entire upper face 4A of said ceramic tiles or slabs 4 .

The hopper 20 comprises, for example, an upper funnel-shaped area 22 into which the liquid ceramic glaze S is fed in, by means of a system of the device 1, better described below.

The upper funnel-shaped area 22 conveys, for example by gravity, the liquid ceramic glaze S towards the underlying calibrated outlet slot 21, defined by two vertical walls 24, 25, mutually parallel and arranged at a suitable distance from each other, depending on the thickness of the enamel blade to be obtained.

Device 1, as better described below, acts as a ?tap? ON/OFF for the intermittent opening and closing of the liquid ceramic glaze outlet S from the calibrated outlet slot 21, in phase relation, respectively, with the transit of a ceramic tile or slab 4 (Figs. 5, 6, 8 ) or an empty space 5 (Fig.7).

The device 1, in general, ? consisting of:

- ? first means 11 for feeding said liquid ceramic glaze S into the hopper 20, in quantity? exceeding the consumption of the same liquid ceramic glaze S as a consequence of its leakage from said calibrated outlet slit 21;

- ? second means 12 for extracting the excess liquid ceramic glaze S from inside the hopper 20, and for recirculating at least part of the recovered liquid ceramic glaze S;

- ? members 13 for regulating the pressure inside the hopper 20, associated with the aforementioned first and second means 11, 12;

- ? control and command members 14, associated with said members 13 for regulating the internal pressure of the hopper 20 and provided for selectively actuating the same so as to determine: a working condition W of the device 1, in which the internal pressure of the hopper 20 ? maintained equal to or greater than the external atmospheric one, cos? to allow the regular descent of the liquid ceramic glaze S towards the calibrated outlet slot 21, in phase relationship with the passage, below the latter, of a ceramic tile or slab 4 (Figs.5, 6, 8); a block condition N of the device 1, in which the internal pressure of the hopper 20 ? maintained, however, less than the external atmospheric one, cos? to stop the descent of said liquid ceramic glaze S, interrupting its delivery, in the time interval necessary for the passage of each of said empty spaces 5 (Fig.7).

In a first embodiment of the device 1, schematized in Fig. 3, said first supply means 11 comprise:

-? a tank 110 for containing liquid ceramic glaze S; - ? a delivery pipe 111 of said liquid ceramic glaze S, extending from the tank 110 up to an inlet hole 23M in said hopper 20;

- ? a pump 112, preferably of the screw type, associated with said delivery pipe 111, provided for taking liquid ceramic glaze S from the tank 110 and sending it, under pressure, towards said inlet hole 23M.

The aforementioned second extraction means 12 comprise a recovery duct 121 of the liquid ceramic glaze S, extending from an outlet hole 23R of the hopper 20 until it flows into the tank 110.

Advantageously, ? it is envisaged that said inlet 23M and outlet 23R holes be made laterally in said hopper 20, so as to be mutually opposite and aligned according to a direction parallel to said calibrated outlet slot 21.

The aforementioned members 13, for regulating the pressure inside said hopper 20, comprise:

- ? a three-way valve 130, associated with the delivery pipe 111, downstream of the pump 112, provided for directing said liquid ceramic glaze S towards the hopper 20 and/or towards an auxiliary pipe 113 for the return of said liquid ceramic glaze S towards the tank 110;

- ? a first pressure gauge 131, associated with the delivery pipe 111, immediately upstream of the hopper 20, provided for measuring the pressure entering the latter of the aforementioned liquid ceramic glaze S and for sending a corresponding signal to said control and command members 14 ;

-? a second pressure gauge 132, associated with said recovery pipe 121, immediately downstream of the hopper 20, provided for measuring the pressure of the liquid ceramic glaze S leaving the latter and for sending a corresponding signal to said control and command members 14;

-? a shut-off valve 133 associated with the recovery pipe 121, downstream of said second pressure gauge 132.

The organs of control and command 14, as already? mentioned, ensure the correct functioning of the device 1, in phase with the succession of advancement of ceramic tiles or slabs 4 and empty spaces 5, and for this purpose they comprise:

-? measuring organs 141 of the speed? V of conveyor line 3;

-? sensor members 142 positioned along said conveying line 3, upstream of the glazing head 2, provided for detecting the position and width of each of the aforementioned empty spaces 5 between one ceramic tile 4 and another, and for sending a corresponding signal;

-? a?unit? of processing 143, foreseen for receiving the data supplied by the cited speed measuring devices 141? and sensor members 142, in addition to those provided by the aforementioned first and second pressure gauges 131, 132, and to process them using suitable software to obtain the time parameters with which to activate and deactivate said pressure regulation members 13.

Pi? in particular, the control and command members 14, to define the aforementioned working condition W of the device 1, actuate the three-way valve 130 so as to open the delivery of the liquid ceramic glaze S towards the hopper 20, with a predetermined pressure of supply, measured by the first pressure gauge 131 and, at the same time, the shut-off valve 133 in the recovery duct 121 is opened, to open the passage to the liquid ceramic enamel S leaving the hopper 20 on its return towards the tank 110; the outlet pressure is measured by the second pressure gauge 132.

With a suitable adjustment of the openings of the three-way valves 130 and shut-off valves 133, such that the supply pressure of the liquid ceramic glaze S ? higher than the return pressure of the same, in the hopper 20 the said condition is determined whereby the internal pressure ? equal to or greater than the external atmospheric one, cos? to allow the regular descent of the liquid ceramic glaze S towards the calibrated outlet slit 21 (Figs. 5, 6, 8).

When the empty space 5 which separates the ceramic tile or slab 4 from the next one arrives, the control and command members 14 switch the device 1 to the aforementioned block condition N, in a suitable phase relationship, closing both the three-way valve 130 and the shut-off valve 133.

In this way the delivery of the liquid ceramic glaze S towards the hopper 20 is stopped and, at the same time, the recovery pipe 121 is closed, thus that an air pocket 26 remains inside the hopper 20, above the level of the liquid ceramic glaze S contained therein, which no longer has an air pocket. communication with the outside: gravity, which tends to make the liquid ceramic glaze S descend towards the calibrated outlet slot 21, causes an increase in the volume of the air pocket 26, in which the pressure becomes proportionally more? low, in any case lower than the external one, thus preventing, in combination with the atmospheric pressure rising from the calibrated outlet slot 21, the descent of the liquid ceramic glaze S, interrupting its delivery, in the time interval necessary for the passage of each of said empty spaces 5 (Fig.7).

In a second embodiment of the device 1, schematized in Fig.4, said first supply means 11 comprise:

-? the aforementioned tank 110 for containing the liquid ceramic glaze S;

-? said delivery pipe 111 of said liquid ceramic glaze S, extending from the tank 110 up to an inlet hole 23M in said hopper 20.

Similarly to what already? said with reference to the first embodiment of the device 1, the second extraction means 12 comprise a recovery pipe 121 of the liquid ceramic glaze S, extending from an outlet hole 23R of the hopper 20 until it flows into the tank 110.

The aforementioned members 13, for regulating the pressure inside said hopper 20, in this case comprise:

-? a first pump 112, preferably with a screw, similar to the one mentioned above, associated with the delivery pipe 111, designed to take liquid ceramic glaze S from the tank 110 and send it, under pressure, towards the inlet hole 23M; -? a first pressure gauge 131, associated with the delivery pipe 111, downstream of said first pump 112 and immediately upstream of the hopper 20, provided for measuring the pressure entering the latter of the aforementioned liquid ceramic glaze S and for sending a corresponding signal to said control and command members 14; -? a second pressure gauge 132, associated with the recovery pipe 121, immediately downstream of the aforementioned hopper 20, provided for measuring the outlet pressure from the latter of the aforementioned liquid ceramic glaze S and for sending a corresponding signal to the control and command members 14;

-? a second pump 134, also preferably with a screw, associated with the recovery pipe 121, downstream of the second pressure gauge 132, designed to draw liquid ceramic glaze S from the hopper 20 and to send it, under pressure, along said recovery pipe 121, towards tank 110.

The organs of control and command 14, similarly to what already? described above, comprise said measuring members 141, said sensor members 142 and the aforementioned unit? processing system 143, intended to receive the data supplied by these and by the aforementioned first and second pressure gauges 131, 132, and to process them in a manner suitable for piloting said pressure regulating members 13.

Pi? in particular, the control and command elements 14, in order to define the aforementioned working condition W of the device 1, operate the first and second pumps 112, 134 in such a way that the inlet pressure of the liquid ceramic glaze S, in the hopper 20 , is higher than the pressure?outlet from the latter, as well as? return to the tank 110 of the same liquid ceramic glaze S.

The pressure differential created, ? suitably registered by the unit? processing module 143 by means of the signals sent by the first and second pressure gauges 131, 132.

As a result of this differential, the said condition is determined in the hopper 20 whereby the internal pressure ? equal to or greater than the external atmospheric one, cos? to allow the regular descent of the liquid ceramic glaze S towards the calibrated outlet slot 21 (Figs.5, 6, 8).

When the empty space 5 that separates the ceramic tile or slab 4 from the next arrives, the control and command members 14 switch the device 1 to the aforementioned block condition N, in phase relationship, varying the flow rates of the first and second pump 112, 134 so that the condition is reversed, in which the inlet pressure is ? lower than the output one: to obtain what has just been said ? it is possible for the first pump 112 to be physically stopped.

In this way a higher pressure is determined in the air pocket 26 inside the hopper 20. low, however lower than the external one, which reproduces the condition already? previously described capable of preventing the descent of the liquid ceramic glaze S, interrupting its delivery, in the time interval required for the passage of each of said empty spaces 5 (see again Fig.7).

The operating logics of both the first and second embodiments of the device 1, for the purposes of precise synchronization in the switching between the working condition W and the blocking condition N, and vice versa, and the successive transit of ceramic tiles 4 and empty spaces 5, do they take into account the greater or lesser speed? of advancement V of these along the conveyor line 3, varying the advances of the controls for this purpose.

Advantageously, the device 1 provides, for both embodiments described, a mixing member 114 inside the tank 110, of a substantially known type, intended to keep the liquid ceramic glaze S contained therein homogeneous.

Furthermore, as illustrated in Figs. 3 and 4, ? provided, as an optional equipment, a system 15 for the collection of liquid ceramic glaze S possibly dripped from the calibrated outlet slot 21 and/or from the edges of the ceramic tiles or slabs 4, comprising a tank 150 arranged below said conveyor line 3, and a pipe 151 provided for discharging the liquid ceramic enamel S, fallen into said tank 150, and introducing it into said recovery pipe 121.

In a known way, the system 15 comprises shut-off valves and a discharge duct 152, which branches off from the pipe 151 and provides for evacuating liquid detergents used for cleaning the tank 150 and, possibly, the hopper 20.

From the above description, all the advantageous aspects of the proposed device emerge very clearly, which allows to instantly stop the delivery of the liquid ceramic glaze whenever the empty space between one ceramic tile and the next one passes below the glazing head. from the transport line.

It is highlighted how the conformation of the shutter element acts advantageously in mode? ON/OFF both in opening and closing, avoiding hysteresis between the command and its actuation.

Furthermore, both constructive solutions proposed with the embodiments of the devices described are advantageously shaped in such a way that the consent for the descent of the glaze from the hopper, or its arrest, depends solely on an original pressure play, without resorting to any conventional type of mechanical barrier to be operated.

From this derives a high speed? reaction to the commands, both in closing and in opening, guaranteeing certain and reliable operation over time.

A further advantage derives from the fact that the organs which determine the described pressure variations inside the hopper are all outside the latter and within the structure of the veiling head, so that the proposed device pu? also be applied to the heads of glazes already? existing without modifications of any kind.

Particular attention, in the design and construction of the device, ? was dedicated to obtain the correct phase synchronization between the stop and the resumption of the dispensing of liquid ceramic enamel with the beginning and the end of the passage of each empty space, equipping the device with the necessary operating parts suitable for this purpose.

The aforementioned phase synchronization is checked and corrected in real time, if necessary, thanks to the foreseen active control systems, which are able to detect speed variations? of the conveyor line and/or differences in length between one of said empty spaces and the others, to avoid production waste on the ceramic tiles or slabs.

In practice, even if such a situation hardly occurs in reality? productive, the proposed device? capable of automatically adapting its operation even if tiles of different lengths are brought under the glazing head.

Ultimately, with the proposed device, a considerable saving of expensive liquid ceramic glaze is obtained, avoiding the waste that is inevitable today, greater cleanliness of the entire ceramic tile transport line, fewer machine stops for cleaning operations and, last but not less important, a large reduction of polluting material to be disposed of respecting the environment, all of this? bringing an appreciable saving in production costs.

However, it is understood that what described above has a non-limiting example value, therefore any variants of detail that may be necessary for technical and/or functional reasons, are considered from now on to fall within the same protective scope defined by the claims below.

Claims (9)

1. Device for controlling the exit of liquid ceramic glaze (S) from a glazing head (2), with the latter arranged above a conveyor line (3) on which they advance at high speed. constant (V) ceramic tiles or slabs (4) arranged in orderly succession, in which ? an empty space (5) is provided between each of said ceramic tiles or slabs (4) and the next, with the same glazing head (2) essentially consisting of a hopper (20) affected at the bottom by a calibrated outlet slot ( 21), from which emerges a blade of said liquid ceramic glaze (S) intended to uniformly cover a part or the entire upper face (4A) of said ceramic tiles or slabs (4), with the aforementioned device (1) characterized by the fact to understand: - ? first means (11) for feeding said liquid ceramic glaze (S) inside said hopper (20), in quantity? exceeding the consumption of the same liquid ceramic glaze (S) as a result of its leakage from said calibrated outlet slit (21); - ? second means (12) for extracting said excess liquid ceramic glaze (S) from inside said hopper (20), and for recirculating at least part of the recovered liquid ceramic glaze (S); - ? members (13) for regulating the pressure inside said hopper (20), associated with the aforementioned first and second means (11, 12); - ? control and command members (14), associated with said members (13) for regulating the internal pressure of the hopper (20) and provided for selectively actuating the same so as to determine: a working condition (W) of the device (1 ), in which the internal pressure of the hopper (20) ? maintained equal to or greater than the external atmospheric one, cos? to allow the regular descent of said liquid ceramic glaze (S) towards said calibrated outlet slit (21), in phase relationship with the passage, below the latter, of one of said ceramic tiles or slabs (4); a block condition (N) of the device (1), in which the internal pressure of the hopper (20) ? maintained, however, less than the external atmospheric one, cos? to stop the descent of said liquid ceramic glaze (S), interrupting its delivery, in the time interval necessary for the passage of each of said empty spaces (5). 2. Device according to claim 1, characterized in that said first supply means (11) comprise: a tank (110) for containing said liquid ceramic glaze (S); a delivery duct (111) of said liquid ceramic glaze (S), extending from said tank (110) to an inlet hole (23M) in said hopper (20); a pump (112), associated with said delivery duct (111), provided for taking liquid ceramic glaze (S) from said tank (110) and sending it, under pressure, towards said inlet hole (23M), from the fact that said second extraction means (12) comprise a recovery duct (121) of said liquid ceramic glaze (S), extending from an outlet hole (23R) of said hopper (20) until it flows into the aforementioned tank (110 ), by the fact that said members (13) for regulating the pressure inside said hopper (20) comprise: a three-way valve (130), associated with said delivery pipe (111), downstream of the aforementioned pump (112 ), provided for directing said liquid ceramic glaze (S) towards said hopper (20) and/or towards an auxiliary pipe (113) for the return of said liquid ceramic glaze (S) towards said tank (110); a first pressure gauge (131), associated with said delivery duct (111), immediately upstream of the aforementioned hopper (20), provided for measuring the pressure entering the latter of the aforementioned liquid ceramic glaze (S) and for sending a corresponding signal to said control and command members (14); a second pressure gauge (132), associated with said recovery duct (121), immediately downstream of the aforementioned hopper (20), provided for measuring the outlet pressure from the latter of the aforementioned liquid ceramic glaze (S) and for sending a corresponding signal to said control and command members (14); a shut-off valve (133) associated with said recovery pipe (121), downstream of said second pressure gauge (132), and by the fact that said control and command members (14) are provided for actuating said three-way valve (130) so as to open the delivery of the liquid ceramic glaze (S), towards said hopper (20), with a pre-set supply pressure, and to simultaneously open said shut-off valve (133) in the recovery duct ( 121), to define the aforesaid working condition (W) of the device (1), or intended to actuate said three-way valve (130) so as to close the delivery of the liquid ceramic glaze (S) towards said hopper (20) , and to simultaneously close said shut-off valve (133) in the recovery duct (121), to define the aforementioned block condition (N) of the same device (1). 3. Device according to claim 1, characterized in that said first supply means (11) comprise: a tank (110) for containing said liquid ceramic glaze (S); a delivery duct (111) of said liquid ceramic glaze (S), extending from said tank (110) to an inlet hole (23M) in said hopper (20); by the fact that said second extraction means (12) comprise a recovery duct (121) of said liquid ceramic glaze (S), extending from an outlet hole (23R) of said hopper (20) until it flows into said tank (110), from the fact that said members (13) for regulating the pressure inside said hopper (20) comprise: a first pump (112), associated with said delivery pipe (111), designed to withdraw liquid ceramic glaze ( S) from the aforementioned tank (110) and to send it, under pressure, towards said inlet hole (23M); a first pressure gauge (131), associated with said delivery pipe (111), downstream of said first pump (112) and immediately upstream of the aforementioned hopper (20), intended to measure the pressure entering the latter of the aforementioned liquid ceramic enamel (S) and to send a corresponding signal to said control and command members (14); a second pressure gauge (132), associated with said recovery duct (121), immediately downstream of the aforementioned hopper (20), provided for measuring the outlet pressure from the latter of the aforementioned liquid ceramic glaze (S) and for sending a corresponding signal to said control and command members (14); a second pump (134), associated with said recovery duct (121), downstream of said second pressure gauge (132), designed to recall liquid ceramic glaze (S) from said hopper (20) and to send it, under pressure, along said recovery duct (121), towards the aforementioned tank (110), and by the fact that said control and command members (14) are provided for operating said first and second pumps (112, 134) in such a way that the pressure d ?inlet of the liquid ceramic enamel (S), in the aforementioned hopper (20), is higher than the outlet pressure from the latter of the same liquid ceramic enamel (S), to define the aforementioned working condition (W) of the device ( 1), or intended to operate the aforementioned first and second pumps (112, 134) so that the said inlet pressure of the liquid ceramic glaze (S) is lower than the outlet pressure, to define the aforementioned block condition ( N) of the same device (1). 4. Device according to claim 2 or 3, characterized in that said control and command means (14) comprise: speed measuring members (141); (V) of said conveyor line (3); sensor members (142) positioned along said conveying line (3), upstream of said glazing head (2), provided for detecting the position and width of each of the aforementioned empty spaces (5) between a ceramic tile (4) and the other, and to send a corresponding signal; a?unit? of elaboration (143), foreseen to receive the data supplied by the cited organs measuring (141) of speed? (V) and sensor elements (142), in addition to those provided by the aforementioned first and second pressure gauges (131, 132) and to process them using suitable software to obtain the time parameters with which to activate said elements (13) for regulating the pressure inside said hopper (20). 5. Device according to claim 2 or 3, characterized in that said inlet (23M) and outlet (23R) holes are made laterally in said hopper (20), so as to be mutually opposite and aligned in a parallel direction to said calibrated outlet slit (21). 6. Device according to claim 2, characterized in that said pump (112), associated with said delivery duct (111), is of the screw type. 7. Device according to claim 3, characterized in that said first pump (112), associated with said delivery pipe (111), and said second pump (134), associated with said recovery pipe (121), are of the type screw. 8. Device according to claim 1 or 2 or 3, characterized in that ? a mixing member (114) is provided inside the aforementioned tank (110), intended to keep the liquid ceramic glaze (S) contained therein homogeneous. 9. Device according to claim 1 or 2 or 3, characterized in that ? a plant (15) is provided for the collection of liquid ceramic glaze (S) dripped from said calibrated outlet slot (21) and/or from said ceramic tiles or slabs (4), comprising a tank (150) arranged below said line conveyor (3), and a pipe (151) provided for discharging the liquid ceramic enamel (S) fallen into said tank (150) and introducing it into said recovery pipe (121).