DEVICE FOR FILTERING ROLLING OIL

Abstract

Device for filtering rolling oil, including: a tank having an inlet for the oil to be filtered, as well as a lid having at least one plate element, or a plurality of plate elements, removably stacked in the internal volume of the tank, able to be removed from the tank via the upper opening of the lid, each of the plate elements removably receiving filtration cartridges, each of the hollow plate elements constituting a collector for oil filtered by the cartridges of said plate element, each of the plate elements comprising a filtered oil outlet removably connected to a corresponding outlet of the tank via a connector. According to the invention, there are between one and three plate elements, the total number of filtration cartridges of the device is between 500 and 3000 cartridges, and is suitable to allow a nominal filtration flow of between 1000 L/min and 4000 L/min.

Claims

1. Oil filtration device (1), comprising: a tank (10) comprising an inlet for oil to be filtered, as well as a lid at least one plate element, even multiple plate elements, superimposed in the internal volume of the tank, removable, able to be removed outside of the tank by the upper opening of the lid, each one of the plate elements holding filtration cartridges that can be removed, each one of the plate elements, hollow, constituting a collector for the oil filtered by the cartridges of said plate element, each one of the plate elements comprising a filtered oil outlet connected so that it can be removed, to a corresponding outlet of the tank by the intermediary of a connector, wherein charactcriscd in that: there are between one and three plate elements (11, 12, 13), the total number of filtration cartridges of the device is between 500 and 3,000 cartridges, and in such a way to allow a nominal filtration flow between 1,000 l/min and 4,000 l/min.

2. Device according to claim 1, wherein the number of plate elements (11, 12, 13) is equal to three, the nominal filtration flow being between 3,000 l/min and 4,000 l/min.

3. Device according to claim 1, wherein the number of plate elements is equal to two, the nominal filtration flow being between 2,000 l/min and 3,000 l/min.

4. Device according to claim 1, wherein the number of plate elements is equal to one, the nominal filtration flow being between 1,000 l/min and 2,000 l/min.

5. Device according to claim 2, wherein the useful volume of the tank (10) of the filtration device (1) is less than 15 m.sup.3, between 9 m.sup.3 and 12 m.sup.3 when the device has three plate elements (11, 12, 13).

6. Device according to claim 1, wherein the length of the cartridges is between 16 inches and 24 inches, in other words, between 40.64 cm and 60.96 cm.

7. Device according to claim 1, wherein the diameter of the tank (10) is between 1.5 meters and 2.3 meters.

8. Device according to claim 1, wherein the height of said tank is less than 4 m, between 3 and 4 meters when the device has three plate elements (11, 12, 13).

9. Oil recycling and filtration facility of a rolling mill, presenting a circuit comprising, successively, according to the oil flow direction: a dirty oil reservoir (2), a filtration system (100) comprising several oil filtration devices (1) according to claim 1, a clean oil reservoir (3).

10. Facility according to claim 9, wherein said dirty oil reservoir (2) being located at a lower level to the rolling mill (M), in a cellar, the clean oil reservoir (3), and the filtration system (100) are located outside of the cellar, at a higher level.

11. Facility according to claim 10, wherein said dirty oil reservoir (2) is located in said cellar, in the immediate proximity of said rolling mill (M).

12. Facility according to claim 9, of which the circuit presents a pumping system (4) and a valve system (6) to control the clean oil flow arriving at the rolling mill, as well as an exchanger system (5), intended to control the temperature of the clean oil, wherein and in that said pumping system (4), said valve system (6) and the exchanger system (5) are located outside of the cellar, at a higher level.

13. Facility according to claim 9, wherein the rolling mill is a 20-Hi rolling mill.

14. A method of recycling and filtering oil for a rolling mill, comprising: providing the facility of claim 9; and operating the facility to recycle and filter said oil; wherein the facility is constructed and arranged to recycle and filter a rolling oil flow of between 4,000 /min and 27,000 l/min.

15. The device of claim 2, wherein the number of cartridges per plate element is between 500 and 1,000.

16. The device of claim 3, wherein the number of cartridges per plate element is between 500 and 1,000.

17. The device of claim 4, wherein the number of cartridges per plate element is between 500 and 1,000.

18. Device according to claim 2, wherein the length of the cartridges is between 16 inches and 24 inches, in other words, between 40.64 cm and 60.96 cm.

19. Device according to claim 3, wherein the length of the cartridges is between 16 inches and 24 inches, in other words, between 40.64 cm and 60.96 cm.

20. Device according to claim 4, wherein the length of the cartridges is between 16 inches and 24 inches, in other words, between 40.64 cm and 60.96 cm.

Description

[0056] The invention will be best understood upon reading the following description, accompanied by its appended drawings, amongst which:

[0057] FIG. 1 is a diagrammatic view of an oil recycling facility of a 20-cylinder rolling mill, such as known from the state of the art,

[0058] FIG. 2 is a view of a five-plate filtration device, such as known from the state of the art,

[0059] FIG. 2a is a photo of a plate with its cartridges of a device of the type in FIG. 2,

[0060] FIG. 3 is a view of the floor layout of the equipment of a recycling facility according to the state of the art in FIG. 1,

[0061] FIGS. 4 and 5 are respectively views comparing a filtration device according to the state of the art (FIG. 4) and a filtration device according to the invention (FIG. 5),

[0062] FIGS. 6 and 7 are a view of a new floor layout of the equipment of a recycling facility according to the invention.

[0063] We start firstly, by describing the architecture of a recycling and rolling oil filtration facility, such as known from the state of the art, and such as illustrated in FIGS. 1 to 4 for a 20-Hi rolling mill M′.

[0064] The facility presents a circuit, illustrated diagrammatically in FIG. 1 and which comprises, between a dirty oil outlet of the rolling mill and a clean oil inlet, according to the normal direction of oil flow:

[0065] a dirty oil reservoir 2′,

[0066] a pumping system 110′ (supplying the filtration system),

[0067] a filtration system 100′ comprising the filtration devices and pumps,

[0068] a pumping system 120′ (extraction from the filtration system),

[0069] a clean oil reservoir 3′,

[0070] a pumping system 4′ (for the rolling mill M′),

[0071] an exchanger system 5′,

[0072] a valve system 6′.

[0073] In such a circuit, the dirty oil is collected in the dirty oil reservoir 2, before being channeled, pushed by the pumping system 110′ into the filtration system 100′. The filtered oil is then stored in the clean oil reservoir 3′. The pumping system 4′ and valve system 6′ then supplies the rolling mill M′ according to the nominal flow desired in the rolling mill. The exchanger system 5, in particular a water/oil-type, enables the desired temperature of the oil to be adjusted. The illustrated facility is sized to ensure a constant fluid flow to the rolling mill, typically between 4,000 l/min and 27,000 lmin, the filtration system 100 ′ comprising multiple plate filtration devices 100 ′ (four of them in FIG. 1), of the type of the manufacturer SUPAMIC, and known since the 1970s, in this type of recycling facility.

[0074] Such a filtration device comprises, such as illustrated in FIG. 2, a tank 10′, typically cylindrical inside which several “plates” are superimposed, removable, marked 11′, 12′, 13′, 14′ and 15′, spread out over the height of the tank, and stacked on top of each other using base systems. Each one of the plates is a hollow element, whereon a large number of filtration cartridges are fixed, parallel, typically by screwing from the upper edge of the cartridge onto the corresponding threaded parts of the plate.

[0075] The tank 10′ comprises an opening for the dirty oil 16′, lower and an overflow opening 17′, located above the plates. Filtration is achieved through the filtering medium of the different cartridges, from outside to inside, the oil filtered by the cartridges being collected in each one of the plates, which are hollow elements, then led to a plate outlet for clean oil. The oil outlets of different plates are respectively connected, watertight, at openings spread out over the height of the tank, using flange sets. The different outlets 18′ of filtered oil join together in one same vertical pipe 19′.

[0076] To the inventor's knowledge, in order to limit the number of filtration devices, and with the aim of limiting the costs of the facility, it is useful for a person skilled in the art to choose high filtration capacity filtration devices, with a higher capacity than 4,000 l/min and which always have four or five plates.

[0077] FIG. 4 illustrates such a five-plate filtration device presenting the following characteristics:

[0078] Number of plates: 5,

[0079] Length of cartridges: 13 inches (that is 33.02cm),

[0080] Number of cartridges: 4,160 (832 cartridges per plate),

[0081] Height of the tank device: 6.1 meters,

[0082] Useful volume (oil): 18 m.sup.3,

[0083] Duration of unclogging: 30 minutes.

[0084] Such a filtration device presents a filtration capacity higher than 4,000 l/min. The filtration system of a recycling and filtration facility equipping a rolling mill, of which the oil flow is 12,000 l/min only requires three devices 1′, according to FIG. 4, arranged parallel, and such as illustrated in FIG. 3.

[0085] The filtration cartridges used often comprise a nylon or fibreglass-based filtering medium. In order to extend the lifespan of the cartridges, back flushable-type filter cartridges are used.

[0086] The unclogging of cartridges is carried out at regular time intervals, and is implemented, on plate filtration devices, one by one. For this purpose, a fluid back flush is implemented (compressed air) on one of the plate filtration devices, and while the other plate filtration devices, positioned parallel, ensure the filtration of the rolling oil. For each device, the unclogging is implemented plate by plate, and not simultaneously on all the cartridges of different plates.

[0087] The invention is born of the inventor's desire to fundamentally change the sizing of recycling facilities such as known from the state of the art, as well as the floor layout of the different equipment that comprises it.

[0088] The invention is born of the observation by the inventor that four or five-plate filtration devices from the state of the art are beneficial, in that, with a significant filtration capacity, they enable the number of filtration devices needed for the facility to be reduced, but however present the disadvantage of a significant unclogging duration, because of the significant number of plates per device.

[0089] Further still, the invention is born of the observation by the inventor that this significant unclogging duration, as well as the fact of presenting a number of devices in parallel with the smallest possible device obligates the dirty oil reservoir 2′ and the clean oil reservoir 3′ to be oversized, which then obligates a person skilled in the art to arrange this equipment in a wide dedicated cellar, as represented in FIG. 3.

[0090] Indeed, the volume of these two reservoirs is a direct relation to the volume T×ΔD:

[0091] the parameter T represents the time needed to unclog the cartridges of a filtration device and,

[0092] the parameter ΔD, the fall in filtration flow.

[0093] According to the inventor's observations, the higher the number of plates, the larger the parameters T and ΔD will be. Indeed, the unclogging duration is directly proportional to the number of plates. Moreover, and the higher the filtration capacity of each device, the lesser devices there will be, and therefore the more of a fall in ΔD flow there will be, when one of the devices is obstructed for the implementation of back flush cleaning.

[0094] Therefore, the invention aims to design and size a plate-type filtration device in a way to substantially reduce the overall cost of the facility.

[0095] According to the invention, the filtration device is design in such a way to be able to substantially reduce the volumes of dirty oil and clean oil reservoirs.

[0096] Also, the invention relates to an oil filtration device 1, comprising:

[0097] a tank 10 comprising an inlet for oil to be filtered, as well as a lid

[0098] at least one plate element, even multiple plate elements 11, 12, 13, removable, superimposed in the internal volume of the tank, able to be removed outside of the tank 10 by the upper opening of the lid, each one of the plate elements holding filtration cartridges that can be removed, each one of the plate elements, hollow, constituting a collector for the oil filtered by the cartridges of said plate element, each one of the plate elements comprising a filtered oil outlet connected so that it can be removed, to a corresponding outlet of the tank by the intermediary of a connector.

[0099] The plate elements 11, 12, 13 each comprising a hollow body acting as a collector for filtered oil, as well as an outlet intended to be connected to a corresponding opening of the tank. The connection can be made, according to the state of the art, by means of a flange set.

[0100] Fixing the filtration cartridges is done, preferably on the soffit of each plate element, for example by screwing, by means of jointly binding threaded parts. The filtration cartridges achieve oil filtration in parallel with the functioning flow given by the manufacturer of the filtration cartridge, from the outside to the inside of the cartridge.

[0101] Each plate element 11, 12 or 13 can again comprise, according to an embodiment of the base extending from the hollow body up to below the lower edges of the filtration cartridges. This base enables, in particular, the plate elements to be stacked on top of each other: the base of said lowest plate element supports on the bottom of the tank, the base of the upper plate elements supporting respectively on the upper faces of the corresponding lower plates.

[0102] The device can again comprise an overflow opening, located above the plate elements and enabling the non-filtered oil to be recycled up to the inlet opening of the tank.

[0103] According to the invention:

[0104] there are between one and three plate elements 11, 12, 13,

[0105] the total number of filtration cartridges of the device is between 500 and 3,000 cartridges,

[0106] and in such a way to allow a nominal filtration flow between 1,0001/min and 4,000 l/min.

[0107] According to an embodiment (in particular illustrated), the number of plate elements is equal to three, the number of cartridges per plate element being preferably between 500 and 1,000, the nominal filtration flow between 3,000 l/min and 4,000 l/min.

[0108] According to an alternative (not illustrated), the number of plate elements is equal to two, the number of cartridges per plate element being preferably between 500 and 1,000, the nominal filtration flow between 2,000 l/min and 3,000 l/min.

[0109] Again, according to another alternative (not illustrated), the number of plate elements is equal to one, the number of cartridges per plate element being preferably between 500 and 1,000, the nominal filtration flow between 1,000 l/min and 2,000 l/min.

[0110] According to a first characteristic of the invention, the number of plate elements is only three (or less) per filtration device, and not four or five, such as known in recycling and filtration facilities from the state of the art.

[0111] According to the inventor's observations, reducing the number of plate elements to three as a maximum (and not four or five according to the state of the art), enables all the filtration cartridges of the device to be unclogged, by implementing three fluid back flushes as a maximum only (that is, compressed air), and for example, three back flushes successively on the three plate elements 11, 12, 13 of a three-plate device. The number of back flushes implemented corresponds to the number of plate elements of the device.

[0112] Thus, advantageously, a substantial reduction in the unclogging duration is obtained, compared with the filtration device from the state of the art, which requires the implementation of at least four back flushes, even five.

[0113] This reduction in the number of plate elements, moreover enables the height of the device to be limited, and in particular, the height of the tank.

[0114] The filtration device according to the invention is also characterised by its significant filtration capacity, in other words, between 1,000 l/min and 4,000 /min, which enables this number to not be increased too much in a recycling and filtration facility: this filtration capacity of the device is given by the number of cartridges multiplied by the functioning flow of the filtration cartridge (given by the manufacturer). In this regard, the total number of cartridges per device can be between 500 and 3,000.

[0115] More specifically, the total number of cartridges can be:

[0116] between 500 and 1,000 for a one-plate-element filtration device,

[0117] between 1,000 and 2,000 for a two-superimposed-plate-element filtration device,

[0118] between 1,500 and 3,000 for a three-plate-element filtration device.

[0119] The filtration devices can be cleaned by back flush: the filtering medium can be nylon or fibreglass-based.

[0120] The dimensions of the tank, in particular the diameter of the tank 10 is preferably less than or equal to 2.3 meters, in particular between 1.5 meters and 2.3 meters, and in such a way to be able to channel the device by standard-sized container, of which the interior dimensions are as follows:

[0121] width: 2.33 m;

[0122] height: 2.38 m;

[0123] door passage height: 2.30 m;

[0124] length: 5.905 m or 12.04 m.

[0125] The height of the tank can be less than 5 meters, preferably, less than 4 meters such as, for example, 3.1 meters, in particular between 3 and 4 meters when the device comprises three plate elements 11, 12, 13.

[0126] The height of the tank can be between 2 meters and 3 meters when the device has two plate elements.

[0127] The height of the tank can be between 1 meter and 2 meters when the device has one single plate element.

[0128] In order to preserve good filtration capacities, the filtration cartridges can be of a length longer than or equal to 16 inches, preferably of a length between 16 inches (40.64 cm) and 24 inches (60.96 cm), further still preferably between 17 inches (43.18 cm) and 24 inches (60.96 cm), for example, between 18 inches (45.72 cm) and 22 inches (55.88 cm), such as 20 inches (50.80cm). As an example, the nominal functioning flow of a 20-inch filtration cartridge is 1.541/min (cartridges from the manufacturer Hydac or Pall).

[0129] The useful volume (oil holding volume) of the tank of the device can be less than 15m.sup.3, and for example:

[0130] between 9 m.sup.3 and 12 m.sup.3 when the device has three plate elements 11, 12, 13,

[0131] between 6 m.sup.3 and 9 m.sup.3 when the device has two plate elements,

[0132] between 3 m.sup.3 and 6 m.sup.3 when the device has one single plate element.

[0133] Limiting the useful volume of the tank plays a part in reducing the volume of the dirty oil reservoir, which often must enable all the oil contained in the tanks of the different filtration devices to be emptied within it.

[0134] We give as a non-exhaustive example, in comparative table no. 1 below, an example of a filtration device according to the state of the art which is used in a recycling and filtration facility, and its replacement according to the invention.

TABLE-US-00001 Filtration device 1′ Filtration device 1 (State of the art) (Invention) Cartridge length 13 inches (that is 20 inches (that is 33.02 cm) 50.08 cm) Number of cartridges 4,160 2,223 Device diameter (tank) 2.4 metres 2.2 metres Device height (tank) 6.1 metres 3.1 metres Number of plate elements    5    3 Useful device volume 18 m.sup.3 15 m.sup.3 Unclogging duration 29.7 minutes 18.5 minutes

[0135] The filtration system of a rolling mill requiring a rolling oil flow of 12,0001/min will only require three filtration devices 1′ according to the state of the art, assembly parallel, while four devices 1 according to the invention will be necessary.

[0136] The invention also concerns an oil recycling and filtration facility of a rolling mill presenting a circuit comprising, successively, according to the oil flow direction:

[0137] a dirty oil reservoir 2,

[0138] a filtration system 100 comprising one or several oil filtration devices 1 according to the invention,

[0139] a clean oil reservoir 3.

[0140] The filtration system 100 preferably comprises several oil filtration devices 1 according to the invention, able to achieve oil filtration at the same time. The number of devices depends on the oil flow to the rolling mill, typically between 4,000 /min and 27,000 l/min and is preferably higher than or equal to 3.

[0141] The facility can also comprise a pumping system 4 and a valve system 6 to control the clean oil flow arriving at the rolling mill M, below the clean oil reservoir 3, as well as an exchanger system 5, in particular of water/oil, intended to control the temperature of clean oil. The facility can again comprise a pumping system 110 above the devices 1 of the filtration system 100 and intended to push the dirty oil up to the filtration system, a pumping system 120 below the devices 1 of the filtration system 100 and intended to suck the oil through the filtering medium.

[0142] The facility again comprises another unclogging system, implementing a back flush (compressed air), device 1 by device 1, and while the other plate filtration devices, positioned parallel, ensure the filtration of rolling oil. For each device, the unclogging is performed plate by plate, and not simultaneously on all the cartridges of the different plates.

[0143] The devices according to the invention enabling the sizing of the clean oil reservoir 3 and the dirty oil reservoir 2 to be substantially reduced, the invention allows other floor configurations to be considered than that imposed by the state of the art.

[0144] Thus, said dirty oil reservoir 2 can be located at a lower level to the rolling mill (M), in a cellar in particular, in order to recover the oil using gravity. However, and according to the invention, the clean oil reservoir 3 (as well as, in particular, the filtration system 100), can advantageously be located outside of the tank, at a higher level. Likewise, said pumping system 4, said valve system 6, even the exchanger system 5 can be located outside of the cellar, at a higher level, such as illustrated in FIG. 7.

[0145] The decrease of the dimensions of the dirty oil reservoir 2, advantageously allows this to be positioned in a cellar, such as illustrated in FIG. 6, possibly slightly bigger, advantageously in the immediate proximity of the rolling mill, which is often present to allow access to the lower actuator system of the rolling mill. This tank also enables the pumping system 110 of the filtration system to be accommodated.

[0146] The filtration and recycling facility according to the invention finds a specific application for 20-cylinder rolling mills, still called 20-Hi by a person skilled in the art.

[0147] Comparative table no. 2 below, illustrates the simulated gains, for a rolling mill of which the oil flow is 12,000 l/min, for a facility comprising four devices 1 according to the invention (with three plate elements), such as defined in table no. 1, and of which the floor layout is improved according to FIGS. 6 and 7, and in comparison with a facility according to the state of the art, comprising three devices (with five plate elements), according to the state of the art, such as defined in table no. 1, and according to the floor layout known from the state of the art and illustrated in FIG. 3.

TABLE-US-00002 Facility State of the art Invention Delta Gain Number of 12,480 8,892  −7% cartridges Volume of oil 295 m.sup.3 172 m.sup.3 −42% Floor footprint 1,800 m.sup.2 1,300 m.sup.2 −28% (including rolling mill) Volume of 5,200 m.sup.3 3,400 m.sup.3 −35% concrete CO.sub.2 mass (Tank 2,898 kg 966 kg −67% fire safety) Annual cellar 253,440 kW 86,400 Kw −66% ventilation energy

[0148] Moreover, the invention enables substantial gains on costs of cartridges, pumps, valves, reservoirs of the facility and the filtration system which are thus optimised.

[0149] Most of the equipment, including filtration devices, can be transported by standard containers, and unlike the same equipment from the state of the art, which requires exceptional transport.

[0150] Of course, other embodiments would have been able to be considered by a person skilled in the art, without actually moving away from the framework of the invention defined by the claims below.

NOMENCLATURE

[0151] Invention (FIGS. 5 to 7): [0152] 1. Three-plate filtration device, [0153] 10. Tank, [0154] 11, 12, 13. Plate elements, [0155] 2. Dirty oil reservoir, [0156] 3. Clean oil reservoir, [0157] 4. Pumping system (rolling mill), [0158] 5. Exchanger system, [0159] 6. Valve system, [0160] 100. Filtration system, [0161] 110. Pumping system (supplying the filtration system), [0162] 120. Pumping system (extracting the oil from the filtration system), [0163] M. Rolling mill.

[0164] State of the Art (FIGS. 1 to 4): [0165] 1′. Five-plate filtration device, [0166] 10′. Tank, [0167] 11′. 12′, 13′, 14′, 15′. Plate elements, [0168] 16′. Dirty oil inlet opening, [0169] 17′. Overflow opening, [0170] 18′. Filtered oil outlets, [0171] 19′. Filtered oil pipe, [0172] 2′. Dirty oil reservoir, [0173] 3′. Clean oil reservoir, [0174] 4′. Pumping system (rolling mill M′), [0175] 5′. Exchanger system, [0176] 6′. Valve system, [0177] 100′. Filtration system, [0178] 110′. Pumping system (supplying the filtration system), [0179] 120′. Pumping system (extracting the oil from the filtration system), [0180] M′. Rolling mill.