ITMO20080244A1 - MILLING PLANT - Google Patents

Description

Description

"GRINDING PLANT"

TECHNICAL FIELD.

The invention relates to a grinding plant, suitable for grinding raw materials to produce ceramic products.

STATE OF THE TECHNIQUE.

The grinding of raw materials, such as, for example, stone materials for the production of ceramic products, currently takes place according to two procedures: a first process involves the discontinuous grinding of the materials and a second process involves the continuous grinding of these.

According to the first process, the materials to be grinded are introduced into grinding apparatuses which are loaded after being stopped and, after the completion of the grinding operating cycle, they are stopped again to be unloaded and loaded again with another quantity of materials to be grind.

According to the second process, the materials are continuously introduced into the grinding apparatuses through loading openings obtained at one end, without these having to be stopped and the ground materials are discharged, still continuously, from an unloading opening opposite to the loading one. , and obtained at an opposite end with respect to the previous one.

For clarity, it should be remembered that a known grinding apparatus consists of a substantially cylindrical drum, which is supported by a frame with its longitudinal axis which is substantially horizontal.

Inside the cylindrical bodies there are also grinding bodies consisting essentially of spheres of very hard materials that have different diameters and which grind the materials first according to a coarse grain size and then increasingly finer, as the materials approach the discharge opening, from which they come out by overflow.

The cylindrical drum is equipped with a rotation motion around its longitudinal axis and internally defines a grinding chamber equipped on the walls with ribs which are shaped in such a way as to increase the angle of lifting and falling of the grinding bodies during the rotation of the cylindrical drum, possibly also making a partial selection of the ground materials based on their granulometry.

In order to obtain materials with desired particle sizes, plants have been created which are composed of several grinding chambers placed in series and, alternatively, joined together or separated, according to whether their rotation must be joint or independent from each other.

In addition to water, each chamber contains grinding bodies which have predetermined dimensions, according to the granulometric dimensions to be obtained and according to the grinding times desired to obtain these dimensions.

The grinding chambers can also have different diameters and can rotate with different angular speeds, since the grinding is also a function of the angular speeds with which the grinding chambers rotate.

A continuous grinding plant which includes two contiguous grinding chambers which are connected together is known from the Italian patent n ° RE2000U000002.

According to this plant, the material to be grinded is introduced through an introduction opening provided at one end of a first grinding chamber which rotates continuously and which has a smaller diameter, in which grinding bodies are also introduced which have significant dimensions, provided for obtain a first coarse grinding of raw materials.

Due to the rotation, the progressive reduction of the dimensions and the mixing with water, the materials move progressively towards the second grinding chamber contiguous to the first and separated from it by a transversal diaphragm which, however, has a connecting opening between the two grinding chambers.

The materials to be ground, after having undergone a first coarse grinding, enter the second grinding chamber which has a larger diameter than that of the first chamber and, consequently, a higher peripheral speed with the same axial rotation speed.

In this second chamber, grinding bodies are introduced which have considerably smaller dimensions than those of the first chamber and which allow to obtain a significantly finer grinding.

Due to the rotation of the grinding chambers and the constant introduction of further materials into the first grinding chamber, the materials continue to move in an axial direction towards the discharge opening from which they come out by overflow.

This known plant has some drawbacks. A first drawback is that it is not possible to equip the grinding chambers with independent rotation speeds.

Another drawback is that in the event of a failure, for example in a motor that rotates the grinding chambers, the plant is completely unusable and the production cycle stops.

Another drawback is that this plant cannot be expanded or reduced according to the specific needs of the production cycles and, therefore, has high fixed costs that are independent of the quantities of materials to be ground that are ground.

A further drawback is that this type of plant also has high maintenance costs due to the construction complexity, the size of the machines that compose them and the relative components.

A continuous grinding plant which includes two grinding chambers separated from each other and equipped with independent motors is known from the Italian patent n ° RE2003A000013.

According to this patent, two cylindrical grinding chambers are provided, placed one after the other, coaxial and coplanar with each other, which are connected by means of a duct for the passage of the materials from the first chamber upstream to the second chamber downstream.

The two chambers are equipped with independent motors that allow each of these to rotate with different rotation speeds. Furthermore, the first chamber has a feed opening through which the materials to be ground are continuously introduced during rotation, while the second chamber has an opposite discharge opening through which the ground materials are discharged by overflow.

Between the first and the second chamber there is, as mentioned, a duct through which the materials ground in the first grinding chamber pass into the second grinding chamber without interrupting the rotation motion of both.

This duct is arranged coaxially to both chambers and has a much smaller diameter than these, so as to create an inlet and outlet threshold substantially close to the centers of the two chambers. The ground materials pass into the overflow duct from the first grinding chamber and fall into the second grinding chamber.

According to the patent, the latter is also equipped with an independent loading device which allows to introduce, parallel to the connection duct that connects the two chambers and which passes the materials from the first chamber to the second chamber, also additional grinding bodies or substances. additives that favor grinding in the latter.

This type of grinding plant also has some drawbacks.

A first drawback is that if a failure occurs in the first grinding chamber, the grinding cycle must be completely interrupted since the second grinding chamber can only be fed with the already ground materials coming from the first chamber.

A further drawback is that it is not possible, even if required, to feed either the first or the second grinding chamber, in the event that one of these stops working, for example due to a fault.

AIMS OF THE INVENTION.

An object of the invention is to improve the state of the art.

Another object of the invention is to realize a grinding plant, in the specific case of continuous grinding, which allows it to continue to operate even if a part of it fails, while maintaining a production of ground raw materials.

A further object of the invention is to provide a grinding plant which can be enlarged or reduced according to requirements.

Another purpose of the invention is to realize a grinding plant which, being able to be subsequently expanded over time in relation to increasing quantities of work to be performed, allows to contain the initial purchase and operating costs, adapting them over time to the actual quantities of ground materials.

A further object of the invention is to realize a grinding plant which has low purchase and maintenance costs.

According to an aspect of the invention, a grinding plant is provided comprising: at least a first and a second grinding chamber arranged in operational succession, separate and independent from each other and a device for feeding the materials to be grinded, characterized in that said device power supply can be connected alternatively with said first chamber or said second chamber.

The grinding plant therefore allows to obtain the following advantages:

- possibility of alternating the grinding chambers between them if there is a failure in one of them; - adjust the dimensions of the grinding plant according to the needs by adding or eliminating grinding chambers even after the installation of the grinding plant;

reduced costs for the construction of each grinding chamber;

reduced costs for the maintenance of each grinding chamber;

- reduction of the request for money for the initial purchase of a grinding plant with few grinding chambers, which can be subsequently expanded according to the conditions of use.

BRIEF DESCRIPTION OF THE DRAWINGS.

Further characteristics and advantages of the invention will become more evident from the detailed description of an embodiment of a grinding plant, illustrated by way of non-limiting example, in the accompanying drawings in which:

Figure 1 is a schematic side view of a grinding plant;

Figure 2 is an enlarged scale view of a detail of the grinding plant of Figure 1; Figure 3 is a broken top view of a portion of the grinding plant of Figure 1; Figure 4 is a schematic side view of the grinding plant in a second embodiment;

Figure 5 is a top view of the grinding plant of Figure 4.

FORMS OF IMPLEMENTATION OF THE INVENTION.

With reference to Figure 1, 1 indicates a grinding plant which comprises a frame 2 which supports a first grinding chamber 3, a second grinding chamber 4 and a third grinding chamber 5, into which grinding bodies are introduced which have predetermined dimensions.

All these three grinding chambers have a body in the shape of a cylindrical drum and are supported rotating by the frame 2, precisely with supports 102, and with rotation axes XI, X2, X3 substantially horizontal and aligned with each other.

Each of the three chambers has end walls that close the cylindrical drum body and indicated respectively with 3 'and 3' 'those of the first chamber 3, 4' and 4 '' those of the second chamber 4, 5 'and 5' 'those of the of the third chamber 5.

These end walls are centrally provided with inlet and outlet openings, indicated respectively with 103 and 203 those of the first chamber 3, with 104 and 204 those of the second chamber, with 105 and 205 those of the third chamber.

Corresponding segments of open chutes or connecting pipes, indicated by 6 and 7, can be inserted in these inlet and outlet openings, which allow the three grinding chambers 3, 4, 5 to be connected together and to introduce into the first chamber grinding 3 the materials to be ground, together with a predetermined quantity of grinding bodies which have dimensions for carrying out a coarser grinding, coming from a feeding device 8 and unloading the progressively ground materials, from the first chamber 3 towards the second chamber 4 and from this towards the third grinding chamber 5.

Corresponding collection groups 9 are arranged between the first grinding chamber 3, the second grinding chamber 4 and the third grinding chamber 5, and also upstream of the inlet opening 103, designed to collect the ground materials and introduce them into the corresponding chambers. grinding and connected with the chute or pipe segments 6 and 7.

According to a possible embodiment, these collection groups 9 can also comprise vibrating groups combined with the segments of chutes or pipes 6, 7, which cause them to vibrate to facilitate the sliding of the materials.

At least one vibrating unit, of a type known per se to the person skilled in the art, is normally provided in the collection unit 9 which feeds the first grinding chamber 3, for the reason that the materials to be ground, in this phase, are still substantially dry and, therefore, tend to agglomerate, risking to clog the inlet opening 103.

The feeding device 8 comprises, as can be seen in Figures 1 and 3, at least one vertical silo 11 which has a lower discharge opening III which is equipped with metering means and which is placed above an end 110 of a first conveyor at belt 10, which has the opposite end 210 which is connected to a second belt conveyor 12 by means of a connecting chute 13.

The second conveyor 12 is equipped with a reversible belt feed motion and is mounted on a device designed to make it move, as indicated by the dotted lines in Figure 1, along the frame 2.

Furthermore, with reference to Figures 1 and 2, it can be seen that the second conveyor 12 is equipped at its ends 112 and 212 with conveyor elements 14 and 15 facing the corresponding collection groups 9, in such a way as to convey the materials to be ground, or ground in a previous grinding phase, so that these are then introduced into the grinding chambers for which they are intended.

With reference to Figures 4 and 5, it is noted that the first grinding chamber 3, the second grinding chamber 4 and the third grinding chamber 5 are also included in the further embodiment of the grinding plant 1.

However, the latter are arranged so that the respective longitudinal axes "XI", "X2", "X3" are arranged parallel to each other.

Also in this second embodiment, the three grinding chambers 3, 4, 5 are placed at different heights from each other with respect to a support and reference surface, for example the ground "T" and, more precisely, the first chamber grinding chamber 3 is placed higher than the second grinding chamber 4 which, in turn, is higher than the third grinding chamber 5.

In this case, the first belt conveyor 10 comprises a first section 10A, indicated in the Figures with a solid line, and a second extension section 10B.

The first section 10A is designed to take the material to be ground which is discharged in a dosed manner from the discharge opening 111 of the silo 11 and directly feed the first grinding chamber 3.

The second section 10B is instead arranged to feed directly, if required, the third grinding chamber 5 or the second belt conveyor 12 which, in this case, as seen in Figure 5, is arranged parallel to the "X2 axis. "of the second grinding chamber 4.

As can be seen from Figures 4 and 5, the grinding chambers are connected to each other with segments of chutes or pipes 6 and 7 and upstream of the inlet openings of each of these, the installation of collection groups 9 can be provided. operation of the grinding plant according to the first embodiment is as follows: a quantity of materials to be ground is introduced into the silo 11 through a loading opening 211 of the latter.

The materials to be ground are then unloaded through the unloading opening 111 on the underlying end 110 of the first belt conveyor 10 which transports them, lifting them up to the second conveyor 12, onto which they are unloaded by means of the connecting chute 13.

This second conveyor can send the materials to be ground unloaded from the connecting chute 13 both towards the end 112 and towards the opposite end 212, simply by reversing its own sliding motion.

If the materials to be ground are sent in the direction of the end 112, from this, through the conveyor element 14 and the underlying collection unit 9, they are introduced into the first grinding chamber 3 through the connection pipe 6.

This first grinding chamber rotates around its own longitudinal axis "XI" with its own angular speed and proceeds to carry out a first coarse grinding of the materials introduced into it.

The introduction of these materials to be ground takes place continuously and when the level of these inside the first grinding chamber 3 reaches the threshold of the outlet opening 203, the materials overflow and, through the pipe 7, and a further connecting element 107, pass on the collection group 9.

From the latter, through the subsequent pipe 6, the materials to be ground are introduced into the second grinding chamber 4, which rotates around its axis "X2" with its own angular speed, normally different from that of the first grinding chamber 3 , and in this second grinding chamber they are subjected to a finer grinding.

Since the height at which the first grinding chamber 3 is placed on the frame 2 is greater than that of the second grinding chamber 4, and this is placed at a higher level than the third grinding chamber 5, the displacement of the materials to be grinded from one to the other grinding chamber occurs mainly by gravity.

When the level of finely ground materials in the second grinding chamber 4 reaches the outlet opening 204, these, through the connecting pipe 7, the further connecting element 107 and the collection unit 9, are continuously introduced into the third grinding chamber 5.

The latter rotates around its own longitudinal axis "X3" with its own angular speed which, normally, is different from the angular speeds of the first chamber and second grinding chamber, and in this third grinding chamber they are subjected to even more grinding end.

When the grinding cycle is completed, the ground materials are discharged through the outlet opening 205 and sent from it to further production stages.

Also between the second grinding chamber 4 and the third grinding chamber 5 there is a difference in level and, therefore, the passage of the materials between them occurs by gravity.

If the first chamber 3 is blocked due to a problem, the grinding cycle must not be interrupted during its maintenance operations.

In fact, the second conveyor 12 reverses its own sense of sliding, switching it towards the end 212.

From this, the material to be ground is introduced directly into the second grinding chamber 4 and the grinding cycle continues without interruption, temporarily excluding the first grinding chamber 3 and using only the second grinding chamber 4 and the third grinding chamber 5.

In case of emergency conditions, for example when both the first grinding chamber 3 and the second grinding chamber 4 are blocked, the continuous grinding cycle can continue anyway, albeit in a reduced way, using only the third grinding chamber. 5.

For this, the second conveyor 12 is expected to move to the position indicated by the dotted lines in Figure 1 after a quantity of materials to be ground has been deposited on it from the first conveyor 10.

A person skilled in the art can also provide that the second conveyor 12 has a telescopic structure, so as to be able to lengthen or shorten according to need.

With reference to the embodiment illustrated in Figures 4 and 5, it is noted that the operation of the grinding plant 1 is substantially the same as that of the previous embodiment.

The substantial differences between the two consist in the arrangement of the grinding chambers 3, 4, 5 side by side and in the embodiment of the first conveyor 10 and of the second conveyor 12.

The materials to be ground are unloaded from the silo 11 onto the first conveyor 10 which, under normal operating conditions, transports them to the inlet opening 103 of the first grinding chamber 3.

Inside the latter, during rotation, the materials are subjected to a first phase of coarse grinding with grinding bodies of predetermined dimensions.

Water is also introduced into this first grinding chamber 3 and the material that comes out of it is conveyed into the second grinding chamber 4 by means of the chute or pipe segment 7.

The same happens between the second grinding chamber 4 and the third grinding chamber 5.

In the event of a malfunction of the first grinding chamber 3, the first conveyor 10, more precisely the first section 10A thereof, moves towards the second grinding chamber 4, as indicated by the dashed lines in Figure 4, until bringing its end 210 vertically above the second belt conveyor 12 and discharging onto this the material received from the silo 11, by-passing the first grinding chamber 3 which, therefore, can be stopped and subjected to repair operations.

At the same time, the grinding cycle does not stop, being kept active with the second 4 and the third grinding chamber 5.

In the event that the second grinding chamber 4 also fails, the first section 10A of the conveyor 10 unloads the material received from the silo 11 onto the second section 10B which extends up to the inlet opening 105 of the third grinding chamber 5 and unloads inside this is the material to be ground.

Also in this case, therefore, the grinding cycle is not interrupted, even if performed with reduced flow rates.

A last emergency situation can happen when the two second 4 and third grinding chamber 5 are blocked.

Also in this case the grinding cycle is not interrupted since it is at least the first grinding chamber 3 that continues to operate.

Claims (12)

CLAIMS 1. Grinding plant comprising: at least a first and a second grinding chamber (3, 4) arranged in operational succession, separate and independent from each other and a feeding device (8) for the materials to be grinded, characterized in that said device power supply (8) can be connected alternatively with said first chamber (3) or said second chamber (4). 2. Plant according to claim 1, in which said first (3) and second chamber (4) are placed at different heights with respect to a reference support plane (T). 3. Plant according to claim 2, in which said first chamber (3) is located at a height greater than that of said second chamber (4). 4. Plant according to any one of claims 1 to 3, in which said first and second chambers (3, 4) have bodies shaped like cylindrical drums supported by support means (2, 102), rotating around respective longitudinal axes of rotation (XI, X2) and defining first extremity walls (3 ', 4') and opposing second extremity walls (3 '', 4 '') equipped with access openings (103, 203, 104, 204). 5. System according to any one of the preceding claims, in which connection means (6) are interposed between said feeding device (8) and said first chamber (3) and between said first chamber (3) and said second chamber (4) 7, 9} for the transfer of said materials to be ground. 6. Plant according to any one of claims 1 to 5, wherein downstream of said second chamber (4) there is at least a third grinding chamber (5) which can be connected to said second chamber (4), said at least a third chamber (5) being supported in rotation by said support means (2, 102) and placed at a lower height than that of said second chamber (4) with respect to said reference support plane (T). 7. Plant according to any one of claims 1 or 5, wherein said feeding device (8) comprises: accumulation means (11) for materials to be ground, which have a loading opening (211) and an opposing discharge opening ( 111); transport means (10, 12) arranged between said unloading opening (111) and said connecting means (6, 7, 9) and having a loading end (112) and an unloading end (212) reversible alternately . 8. Plant according to claim 7, in which at least between said transport means (10, 12) and said discharge opening (111), metering means for said materials to be ground are provided. System according to any one of claims 1 or 6, wherein said first chamber (3), second chamber (4) and third chamber (5) can be rotated independently of one another. 10. Plant according to any one of the preceding claims, in which said first chamber (3), second chamber (4), third chamber (5) are arranged longitudinally aligned with each other. 11. System according to any one of the preceding claims, in which said first chamber (3), second chamber (4), third chamber (5) are arranged side by side and parallel to each other. 12. Plant according to any one of claims 4, 5, 6, 7, wherein said connection means comprise: - chute / pipe means (6, 7) having first inlet ends facing towards said feeding device (8) or a chamber of said chambers (3, 4, 5) and second outlet ends facing towards and introduced into, said access openings (103, 104, 105) of said ends of said first chamber (3), second chamber (4), third chamber (5), said discharge ends of said transport means being arranged above said chute / pipe (6, 7) in such a way as to discharge said material to be ground onto these.