FILTRATION EQUIPMENT AND A SELF-CLEANING MICROFILTRATION SYSTEM FOR LUBRICATING-COOLING FLUIDS.

Technical field

The present invention relates to filtration equipment and a self-cleaning microfiltration system for lubricating-cooling fluids particularly recommended for the cleaning and the washing of the liquid used for lubrication in the processing typically carried out by machine tools such as lathes or machining centres.

Background Art

As it is known, the liquids used in mechanical processing for removal, shaping, or for unconventional processes, end up polluted with solid particles or contaminants of various origins: fluid degradation products and residues of materials originating from the processing. To ensure reliable performance from the machines which carry out the processing, it is necessary for the liquids to be purified of the impurities resulting from the said processing.

At present, for example, in machining centres or in numerically controlled machines, filter cartridges are used to filter the liquids and the said cartridges must be replaced frequently as they quickly become clogged or broken due to the wear caused by impacts with the swarf, which causes tears in the material of which such filters are made, in addition to the wear caused by operating pressure levels. One of this kind of filter cartridge is illustrated in American patent US 2,988,227. The filtering element consists of a bellows composed of a multitude of folds which are held in position by a toothed section bar made of a plastic material, which keeps the folds spaced apart to allow the passage of the liquid to filter.

The cartridges, described in the American patent, like those mentioned earlier, must be frequently and constantly replaced in order to achieve adequate filtration of the liquids used in the machining centres or in the numerically controlled machines. These maintenance operations involve machine downtime which slows down production with, consequently, increased costs for both the spare cartridges and the slower production speeds, in addition to the necessary constant presence of workers for maintenance work. Furthermore, continuous monitoring of the machines is required to prevent sudden, unexpected interruptions in the processing due to the malfunctioning of the machines resulting from the fluid soiled with particles as a result of cartridges which are not as efficient as necessary. Indeed, when filtration of the fluids is not optimal, there is a risk of considerable damage to equipment due to the presence of impurities and particles in the fluids. It is known that current equipment for numerically controlled machines is extremely sophisticated and delicate and extremely costly and, by now, all such equipment features a cooling system, therefore there is considerable need to be able to filter the liquid coolant effectively and conveniently.

In addition, without correct, adequate filtration, the lubricating-cooling fluids are polluted and must be replaced more frequently with consequent wastage of materials and high costs for both maintenance and waste disposal since the waste is highly polluting and classified as special waste.

As illustrated earlier, the aforesaid machine tools require extremely effective filtration systems since they need the lubricating-cooling liquid to be extremely clean in order to be able to operate correctly and safely and as the pumps which circulate the said liquid operate under high pressure, these must also work with liquids devoid of particles with a diameter of over 10 micron for good operation not only of the pump but also of the machine's other moving parts.

As one might imagine, if there is no efficient filtration, the machines wear quickly with huge and heavy costs for maintenance to restore them, which impacts on the management and production costs as a result of poorly executed processing and/or machine downtime. In particular, the Applicant is aware of French patent n.2989283, which illustrates a filtration system for water employing a diatomaceous earth filter.

The device comprises a chamber inside which there is a series of cage modules present, kept in position by spacers. The modules are covered with a polypropylene fabric which is coated with a layer of diatomaceous earth. The water to be filtered flows through the layer of diatomaceous earth and the fabric and into the module, flowing upwards towards the manifold for the collection of the filtered water, which is then reused.

The water flows in at the bottom, flows through the layer of diatomaceous earth and the fabric, and leaves through the holes in the cage, converging in a delivery manifold. The water to filter is driven by a pump into the filter, entering from the bottom and leaving from the top. During filtration, the diatoms which comprise the layer of diatomaceous earth compact around the fabric, retaining the dirt. When the filtering bed starts to clog, resulting in an increasing loss of power and reducing, therefore, the capacity of the filter, the device illustrated in the patent envisages a cleaning cycle which consists in forcing air into the cage module which makes the polypropylene fabric vibrate; the said vibration breaks the layer of diatomaceous earth and the dirt accumulated ends up on the bottom of the filter. After a series of cycles, the layer of diatomaceous earth must be restored as the said earth becomes spent.

The aforesaid French patent illustrates a low-pressure filtration system whose task is to remove particles which render water turbid (for example, in a swimming pool) and include organic compounds, inorganic compounds, micro-organisms, bacteria, algae, and other elements which differ considerably from the particles present in the lubricating-cooling liquids of machine tools.

In addition to that set out above, the Applicant is the holder of a patent application for a filtration system which envisages, thereinside, the presence of a stem which, with a preset frequency, releases air to detach the filtration residues present on the external surface of the filter and make the said residues fall. The cleaning method just briefly illustrated has highlighted difficulties in achieving adequate and complete detachment of the particles since, as soon as a gap opens due to the detachment of a part of the impurities, the air supplied tends to exit via the said opening, losing part of the power and the cleaning capacity, as a result of which there remain sectors which are not perfectly clean, leading - over time - to a reduction in the filtering capacity.

The cleaning method implemented has highlighted the necessity to reduce the noise experienced when cleaning the filter, by forcing compressed air into the filter to detach the residues from the filtering element.

A further need encountered is due to the fact that, in current tanks for the collection of the dirty fluid laden with particles there is a need to empty out the solid residues which accumulate on the bottom of the tank.

One system for extracting the said residues envisages the presence of a collection basket on the bottom of the tank and therefore, at predetermined intervals, it is necessary to lift the basket, allow the liquid to drain out, then empty out the residues.

The operation just described proves particularly tiring given the weight resulting from the amount of residues present in the basket and the time necessary to strain the liquid from the residues. Furthermore, while removing a large part of the residues, a sort of“sludge” forms on the bottom of the tank, which reduces the clearness of the liquid over time and leads to system downtime for the removal thereof, since the said sludge pollutes the lubricating- cooling fluid.

Disclosure of Invention

The aim of the present invention is essentially to resolve the problems of the commonly known technique, overcoming the aforesaid drawbacks by means of filtration equipment and a self-cleaning microfiltration system for lubricating-cooling fluids which is able to cany out the microfiltration and self-cleaning of the liquid with a cycle which runs automatically and allows the fluid to be recovered and the impurities to be separated for the disposal thereof.

A second aim of the present invention is to produce filtration equipment and a self- cleaning microfiltration system for lubricating-cooling fluids which proves to be highly efficient for all those applications which need a fine filtration system for high-pressure processing liquids.

A further aim of the present invention is to produce filtration equipment and a self- cleaning microfiltration system for lubricating-cooling fluids which can be integrated into the lubricating-cooling circuit of machine tools, thereby allowing the automatic separation of the impurities, preventing interruptions in the processing, and drastically reducing the time and costs of maintenance for cleaning and replacing the filters.

A further aim of the present invention is to provide filtration equipment and a self-cleaning microfiltration system for lubricating-cooling fluids which does not require special maintenance, does not employ disposable filtering materials, has lower operating costs, and offers a drastic reduction in the polluting materials to be disposed of.

A still further aim of the present invention is to provide filtration equipment and a self- cleaning microfiltration system for lubricating-cooling fluids which can curb the management and maintenance costs thereof, thereby allowing greater productivity.

A last but not least aim of the present invention is to produce filtration equipment and a self-cleaning microfiltration system for lubricating-cooling fluids which is easy to manufacture and works well.

These aims and others besides, which will become apparent over the course of the present description, are essentially achieved by means of filtration equipment and a self-cleaning microfiltration system for pressurised fluids as outlined in the claims below.

Brief Description of Drawings Further characteristics and advantages will better emerge in the detailed description of filtration equipment and a self-cleaning microfiltration system for lubricating-cooling fluids, according to the present invention, provided in the form of a non-limiting example, with reference to the accompanying drawings, in which:

- Figure 1 shows, schematically and in a perspective view from the front, filtration equipment for lubricating-cooling fluids according to the present invention;

- Figure 2 shows, schematically and in a perspective view from the rear, the equipment in Figure 1 ;

Figure 3 shows, schematically, a section view of the filtration system of the equipment in Figure 1;

- Figure 4 shows, schematically and in a perspective view, a component of the filtration system according to the present invention;

Figure 5 shows, schematically and in a perspective view, a variant of the component of the filtration system in Figure 4;

Figure 6 shows, schematically and in a perspective view from the front, a variant of the equipment according to the present invention;

- Figure 7 shows, schematically and in a perspective view from the rear, the equipment in Figure 6;

- Figure 8 shows, schematically, the filtration method envisaged for the equipment in question;

Figure 9 shows, schematically, the method of cleaning the filtration system of the equipment in Figure 1 ;

- Figure 10 shows, schematically and in a section view, the operation method of a component of the filtration system of the equipment in question;

Figure 11 shows, schematically and in a section view, the method of cleaning the component in Figure 10; - Figure 12 shows, schematically, a partial section view of a component of the equipment according to the present invention and the diagram of the cleaning and removal of the impurities:

- Figure 13 shows, schematically, a section view of the component in Figure 12. At present, all the machines which use lubricating-cooling fluids which operate under high pressure (for example: machining centres) have, as standard, an emulsion tank with various macrofiltration stages and during the last stage the cleanest emulsion is achieved, which is drawn up by a low-pressure impeller pump with an operating pressure ranging from just a few bars to a maximum of 16 bar, with a flow rate of 15 to 80 litres per minute and above depending on the type of machine and/or the requirements.

In particular, in order to be able to operate correctly, this type of machine needs a particularly clean fluid with a tolerance, in terms of the diameter of the particles present in the fluid, of just a few micron and therefore a fluid microfiltration operation must be carried out.

When installed on machining centres, the filtration equipment according to the present invention fits between the collection tank A and a supplementary tank B, wherein the tank B receives the liquid from the filtration system in question and a pump C draws the liquid from the tank and sends the said liquid, under high pressure, to the machine D, as shown schematically in Figure 8.

As mentioned earlier, users need to eliminate particles with a diameter of over 10 micron from the liquid in order to keep the high pressure pump C and all the chucks (which rotate on ceramic materials) of machine D in good condition.

Now, with reference to the aforesaid figures, and in particular to Figure 1, 1 denotes - as a whole - the filtration equipment with a self-cleaning microfiltration system for lubricating- cooling fluids operating under pressure.

Best Mode for Carrying Out the Invention The filtration system in question is envisaged to be installed downstream of the tank A so as to receive the liquid to be filtered from a pump 15 and send the said filtered liquid to the tank B and, from there (drawn by high-pressure pump C) to the machine D.

The filtration system 1 is essentially constituted of a body 2 essentially cylindrical which is sealed, at one end thereof, by a first closure element 20 equipped with a sealing gasket

20a and connected to a first conduit 21 of the liquid to filter while, at the other end of the body 2, there is a second closure element 22 present connected to a second conduit 23 for the filtered liquid.

In more detail, the first conduit 21 comprises a three-way valve 210 equipped with a pneumatic actuator and a solenoid valve connected to a management and control unit 3, as shown in Figure 1, while the second conduit 23 comprises a two-way valve 230 equipped with a pneumatic actuator and a solenoid valve, also connected to the management and control unit 3.

In more detail, the valve 210 is envisaged to manage, in a first position, the passage of the fluid from the tank A, through the pump 15, into the first conduit 21, which then enters the body 2, as shown in Figure 8, and, in a second position, the passage of discharge fluid of and air from the body 2 towards a decantation tank 8, as shown in Figure 9. The valve 230 is envisaged to manage the passage of clean fluid from the body 2 to the collection tank B. According to the present invention, inside the body 2 there is a filtering element 4 envisaged, which is made of a metal material such as, for example, steel and features a surface which allows the passage of liquid and particles with a diameter of below 10 micron. In more detail, the filtering element 4 is essentially composed of a first internal frame 40 with a spiral structure made of a metal material, preferably stainless steel, of a second outer frame 41 also made of steel and of a filtering layer 42 made of microtextile and stainless steel, located between the due frames. In particular, engaged with the internal frame 40 is the filtering layer 42, which is protected by the outer frame 41 which features a surface endowed with a plurality of holes 4la designed to allow the passage of the fluid, as shown in Figure 4.

One variant, shown in Figure 5, envisages that the outer frame 41, on the external surface thereof, is equipped with a plurality of deflector elements 410 distributed uniformly along the surface. The deflector elements 410 are envisaged to protect the filtering layer 42 preventing the breaking thereof due to direct impact with the particles to be filtered. In this way, it is possible to ensure a high flow rate of the liquid to be filtered.

In addition, the structure of the filtering element 4 allows good wear resistance and, at the same time, a reduction in the space allowing the passage of particles and therefore a filtering capacity is achieved which can stop particles with a diameter of even just under a few micron. Furthermore, the filtering element features a pair of gaskets envisaged to provide a seal with the body 2.

According to the present embodiment, the body 2 features a distribution conduit 2 la, shown in Figure 3, connected to the first conduit 21 for the fluid to be filtered, which extends along the entire length of the said body so as to carry the liquid to be filtered contemporaneously long the entire length of the filtering element. In particular, the distribution conduit 2la features a flow diverter envisaged to create a vortex in the liquid and make it circulate along the walls of the body and along the external surface of the frame 41.

The liquid to be filtered moves tangentially to the filtering element 4 and therefore the particles contained therein do not impact perpendicularly, but tangentially; in this way, the filtering layer 42 is protected and conserved consenting a better quality of filtration and a longer life time.

As already mentioned, from tank A which collects the dirty liquid, the liquid to be filtered through the action of the pump 15 is delivered to the first conduit 21, flows through the valve 210, arrives in the distribution conduit 2 la, enters the body 2 and flows through the filtering element 4. All the particles which are equal to or larger than larger the size set as the filtering capacity (for example 10 micron) are retained on the external surface of the filtering element. The liquid which flows through the walls of the filtering element 4, is cleaned and conveyed towards the second conduit 23 for the clean liquid to leave the body 2 and arrive at the tank B in order to be reused.

According to the present embodiment, connected to the first closure element 20 is a pneumatic cylinder 7 to whose stem 7a is connected a terminal element 70 constituted of a compressed air diffuser located inside the filtering element 4 and whose function will be illustrated later.

Connected to the pneumatic cylinder 7 is a compressed air inlet conduit 71 in which there is a non-return valve 72 present. The conduit 71 is connected to a tank 74 whose task is to supply the pressurised air necessary for the movement of both the stem and the diffuser 70. Furthermore, the tank 74 is also designed to supply pressurised air to a second storage tank 75 which supplies pressurised air for the operation of the solenoid valves connected to the actuators of the valves 210 and 230.

In addition, connected to the tank 74 there is a pneumatic solenoid valve 76 which fulfils the following functions: during the filtration cycle, the valve's task is to keep the stem 7a and the diffuser 70 in the resting condition while, during the filter cleaning cycle, the said valve allows the stem and diffuser to be moved into the in operational condition.

In the present embodiment, the cylinder 7 envisages a pair of flow regulators 73 envisaged to regulate the movement speed of the stem 7a.

According to the present invention, the pneumatic cylinder 7 with the stem 7a and the terminal element 70 featuring a multitude of holes for the passage of air are designed to manage the cleaning of the filtering element 4 on which the particles present in the fluid deposit and which must be eliminated from the said fluid for the good operation of the machining centre, as explained earlier.

In more detail, the terminal element 70 - moved through the action of the stem 7a - lowers inside the filtering element 4 in a uniform manner, releasing air which detaches the dirt and the particles deposited on the external surface of the filtering element, doing so gradually, as the terminal element moves.

The material which is detached is captured by the liquid present between the filtering element 4 and the body 2 and is forced outwards towards the first conduit 21 following the closure of the valve 210 when acting as delivery conduit for the liquid to be filtered and inverting the flow direction of the liquid to direct it towards a tube 25 which is connected to a decantation tank 8, as shown in Figure 8.

For the sake of clarity, when the filtering element 4 cleaning operation is carried out and the flow liquid to be cleaned into the body 2 is interrupted through action on the valve 210, a part of the filtered liquid remains retained within the filtering element. The pressure of the air which is forced in by the diffuser 70 causes the detachment of the particles and the impurities present on the filtering fabric 42, which are pushed, in the liquid present, between the pouter walls 41 of the filtering element 4 and the body 2.

In more detail, the liquid present between the body 2 and the external surface 41 of the filtering element becomes laden with the impurities and is allowed to flow out through the conduit 21 and delivered to the decantation tank 8 through the tube 25.

According to the present invention, liquid mixed with air transits via the tube 25, entering the decantation tank 8, as shown in Figure 9. The liquid introduced into the tank 8 is forced to follow a particular route which allows decantation of the solid particles contained therewithin. Indeed, the liquid, once inside, falls by gravity in the first stage 80, after which the liquid follows a forced route organised into six sectors 81, subdivided by means of partitions 810, as shown in Figure 9. During this route, the liquid releases the particles/impurities which settle, in a forced manner, on the bottom since heavier. At the end of the route, that which flows out is a decidedly improved liquid, which can be reintroduced into the circulation via the tank A for dirty liquid supplied with the machine and containing the lubricating-cooling fluid to be filtered.

The residues 9 which deposit on the bottom of the tank 8 are removed via a screw feeder 10 or further system, which transports them from the bottom and carries them towards a residual particle collection container 11.

The solid residues collected are disposed of in waste disposal centres or as special waste, depending on the processing, or undergoing treatment for the recycling and reused thereof.

The air present in the liquid, meanwhile, tends to rise and follows a route, through a series of bulkheads 82 arranged in an inclined manner, flowing upwards and passing through a first filter 83 whose task is to separate the oil particles present in the air in an atomised form from the air. The air, then, passes through a droplet separator 84 consisting of a honeycomb structure for further filtration. Indeed, the first filter 83 forces the air towards an additional route so as to remove the moisture present in the air and, subsequently - when passing through the second filter 84 - any drops of oil which have been left are removed.

The second separator 84 serves, also, to remove any moisture left in the air, which - when the latter flows out - is captured by an extractor since - while extremely improved - the air is not suitable for breathing.

The decantation tank 8 is a component envisaged in the equipment to allow optimal collection of the polluting residues 9 and the separation thereof from the liquid so as to have significant recovery of the lubricating-cooling fluid, thereby reducing consumption thereof (as occurs with systems according to the commonly known technique) and allowing easier recovery and disposal of the residues which have been separated from the fluid, in addition to preventing the formation of“sludge" in the collection tank A. The decantation tank 8 allows improved performance of the machines D and implements the equipment's functions, but is not a binding component for the equipment.

According to the present embodiment, the entire filtration system is contained in a containment structure 13 for the protection of the components and housed on a trolley 130 for ease of movement of the said filtering equipment as shown in Figures 1 and 2. Indeed, the equipment may be used on multiple machine tools depending on necessities and therefore the presence of the trolley allows convenient handling, in addition to the fact that the equipment envisages all the components required in order to be able to operate independently, unlike with existing filtering systems, which require many external connections.

In addition to that set out above, the equipment comprises a control panel 12, which is of the touch-screen kind, connected to the management and control unit 3. In more detail, the control unit 3 is designed to manage all the functions of the equipment and, in particular, to manage the filtration stage and subsequent cycle for cleaning the filtering element 4. Furthermore, the control unit 3 manages the opening and the closure of the valves at intervals which can be programmed based on the type of processing and of machine D served by the equipment in question.

As illustrated, the cleaning and filtration cycles are managed by the control unit and an operator can program the work time based on the type of machine D and the processing to be carried out.

Furthermore, the filtration system comprises a safety valve 6 set to a pressure of 6 bar, located on the first closure element 20 and envisaged to bleed out liquid and/or air in the event of high operating pressure.

According to the present invention, the equipment may feature two or more filtering elements for greater production of filtered liquid, as shown in Figures 6 and 7. In this condition, there are no interruptions in flow rate since while one filtering element filters, the other runs the cleaning cycle and vice versa, thereby guaranteeing continuous operation. In more detail, given that the time interval envisaged for filtration is greater than that envisaged for cleaning, the equipment can manage the two operations by staggering them over time within each filtering element and therefore the machine never experiences any interruptions during filtering.

As mentioned earlier, the filtration system 1 envisages an operating/work stage in which the liquid is cleaned through the following operating stages:

drawing of liquid from a collection tank A through the action of a pump, input of the liquid into a first conduit 21 through a valve 210 in the body 2, passage of the liquid through a distribution conduit 21a and distribution within a space between the external surface 41 of the filtering element 4 and the internal surface of the body 2 through the action of a flow diverter which creates a vortex in the liquid, making the latter circulate along the walls of the body and along the external surface of the filtering element 4,

filtration of the liquid by means of the passage thereof through the surface of the filtering element 4 with the impurities retained on the external surface 41 thereof,

- outlet of the cleaned liquid via a second conduit 23 through the corresponding valve 230 towards the tank B.

According to the present invention, the filtration system comprises a filtering element 4 cleaning stage comprising the following operating stages:

closure of the valve 230 on the second liquid conduit 23,

- closure of the valve 210 on the first conduit 21 ,

- introduction of air, through the air inlet conduit 71, into the terminal element 70 and inlet of air inside the filtering element in a sequential manner,

opening of the valve 210 in the position to drain the first conduit 21 , movement of the terminal element 70 from an initial position in proximity to the closure element 20 to an end position in proximity to the closure element 22, gradual passage of air through the filtering element with detachment and removal of particles from the external surface of the filtering element and accumulation in the liquid present between the external surface of the filtering element and the internal surface of the body 2,

closure of the valve 72 and interruption of the flow of air into the filtering element, outlet of the dirty particle-laden liquid from the first conduit 21 ,

passage of the concentrated dirty liquid through the tube 25 towards the decantation tank 8.

The filtration system envisages that the filtering element cleaning and washing stage takes place automatically, on command from the control unit 3 present in the equipment at programmable, predetermined intervals, for example, every horn- or, also, at closer intervals based on operating requirements due to the type of liquid and processing.

After the predominantly structural description, the invention in question will now be outlined.

Through the valve 210 and the first conduit 21, the filtration system according to the present invention makes the liquid to be filtered enter the body after being drawn by the pump 15 from the collection tank A and sent to the first conduit 21.

The liquid enters the body and - passing through the distribution conduit 21 a - flows through the filtering element 4 leaving particles and processing residues on the external walls thereof, and then leaving - clean - via the second conduit 23 and the relative valve 230 to go on to the tank B.

The filtration system according to the present invention is designed to run a filtering element 4 cleaning cycle automatically, as shown in Figures 9, 10, and 11, on command from the control unit which manages the activation of the filtering element cleaning cycle. When the control unit activates the cleaning stage, the system carries out the removal of the impurities present on the external surface of the filtering element.

During the filtering element cleaning operations, the valve 210 which is operational during the filtration of the liquid is closed and is opened in the drain position.

A jet of air originating from the storage tank 74 is directed inside the filtering element through the terminal 70 located on the stem of the cylinder 7. In more detail, the stem 7a lowers gradually into the filtering element and the jet of air supplied gradually, sector by sector, hits the internal wall of the filtering element, detaching the particles deposited on the external surface 41 of the filtering element and subsequently mixing with the liquid present in the space between the internal surface of the body 2 and the external surface of the filtering element.

During stem travel and the flow of air, the liquid laden with residues present inside the body 2 is drained via the valve 210 and the first conduit 21 and subsequently flows - through the tube 25 - to the decantation tank 8. In more detail, when the control unit starts operating, a pulse is sent which closes the valve 230 on the second conduit 23 so that the filtered liquid does not flow out, closing, at the same time, the inlet valve 210 on the first conduit 21 so that the liquid to be filtered does not enter and the valve 210 is opened in the drain position so as to connect the conduit 21 to the tube 25. In this condition, the valve 72 on the conduit 71 is opened for a period of approximately 5/10 seconds, making the air enter, which - acting in sectors - will lead to the particles of dirt detaching from the external surface of the filtering element. As the terminal element 70 moves, the liquid laden with residues flows out towards the tube 25, since the valve 210 is in the liquid drain position, and is conveyed to the decantation tank 8. At this point, the filtration system returns to the work stage. During this time span, the filtering element cleaning is carried out, as is the removal of the particles deposited on the external wall of the filtering element and the concentrated dirty liquid is delivered in the decantation tank for the removal of the solid residues.

When the equipment features the two filtering elements, the cleaning operation illustrated earlier takes place with the two filters slightly staggered so as never to interrupt the filtration of the liquid.

The present invention thus achieves the aims set.

The equipment with the filtration system according to the present invention is able to carry out the microfiltration and the self-cleaning of the liquid with a cycle run automatically which allows the fluid to be recovered and the particles separated for the disposal thereof. Advantageously, the filtration equipment and a self-cleaning microfiltration system for lubricating-cooling fluids proves to be high effective for all the applications which need a fine filtration system for processing liquids.

Furthermore, the equipment in question can be integrated into the lubricating-cooling circuit of the machine tools, allowing the separation of the impurities automatically, preventing interruptions in processing and drastically reducing maintenance time and costs for the cleaning and the replacement of the filters. In particular, the equipment with the filtration system guarantees the machine tools (which use high-pressure liquid) a high level of control over the impurities in the fluid, which could obstruct important and delicate parts of the machine.

A further advantage offered by the equipment according to the present invention is that the said equipment does not require particular maintenance, does not employ disposable filtering materials, features lower operating costs, and offers a drastic reduction in polluting materials to dispose of.

Advantageously, the filtration system of the equipment in question allows the filtering element to be cleaned automatically frequently without any machine or system downtime, resulting in better operation of the said filtering element and of the machine to which the equipment is applied thereby, given that the liquid is constantly cleaner.

Furthermore, the filtration system according to the present invention features extremely efficient operation given that, the lifetime thereof is considerable, unlike all the existing filters which experience, over time, a reduction in the filtration capacity thereof (and therefore in the efficiency and operation thereof) until breakage while the filter in question remains unchanged in terms of the characteristics and the filtration capacity thereof given that, after each cleaning cycle, the system according to the invention offers the same performance as that of a new filter. A further advantage of the filtration system in question arises from the fact that the costs of management and maintenance thereof can be curbed, while productivity is increased.

A still further advantage of the filtration system is that the said system offers an improvement in the processing conditions of machines, such as machining centres etc., and an improvement in the serviceability thereof, with consequent reduction in the servicing times and longer maintenance intervals, thereby allowing the machine greater productivity.

In particular, the equipment can manage multiple machine tools, thereby allowing a centralised filtration system to be set up.

Furthermore, since the filtration system cleans the filtering element automatically, there is no longer any need for the presence of staff to oversee the machine to prevent breakages or problems with the components thereof. In addition to that stated above, because of the functions offered, the equipment may easily be adapted to filter other types of liquid while maintaining the structural characteristics thereof. A still further but not final advantage of the present invention is that it is extremely simple to use, easy to manufacture, and works well. Naturally, further modifications or variants may be applied to the present invention while remaining within the scope of the invention that characterises it.