SK42595A3 - Device for filtering of polluted liquids, mainly user oil - Google Patents

Abstract

The invention deals with filtering and processing polluted liquids, in particular used oil, but also creosotes or coolants or cooling water. The aim of the invention is to provide a compact, portable and economic device having however a high specific capacity for filtering out of the liquid particles measuring down to a few micrometers, so that for example the purified oils may be reduced. For that purpose, a device for filtering polluted liquids, in particular oils such as used oils and creosotes, but also coolants or cooling water, has a filter, pumps which press the liquid through the filter, and additional fine filters.

Description

(57) Annotation:

Apparatus for filtering contaminated liquids, in particular oils, waste oils, tar oils, coolants, cooling water and the like, consisting of a filter and pumps (9) for passing liquid through the filter. Downstream of the power filter (11) there are a plurality of ultra fine filters (16) arranged in parallel and a upstream magnetic filter (8) to remove the magnetizable solid particles from the liquid.

M n '

Device for filtering contaminated liquids, especially oils

Technical field

The invention relates to a device for filtering contaminated liquids, in particular oils, waste oils, tar oils, coolants, cooling water and the like, comprising a filter and pumps for passing liquid through the filter.

BACKGROUND OF THE INVENTION

There is known a device with a high throughput filter, which may be referred to as a power filter, and a pump for pumping oil through this power filter, which makes it possible to filter out very coarse foreign particles from the old oil so that the oil can be burned with minimal residue. Thus, the oil cleaned by this generically similar device cannot be used in any other way, for example as a lubricating oil.

In addition, large plants are known, that is to say, whole plants for cleaning and regenerating old oil so that it can be reused or reused. However, the establishment of such large-scale facilities is costing many tens of millions of marks and is economical only if all the old oils are collected from a large area. The process is also associated with high transport costs, which, on the one hand, are seen by people and companies supplying old oils and, on the other, make it impossible for regenerated old oils to be economical enough as compared to new oils. Thus, especially where old oils are produced, there is a clear tendency that these old oils cannot be regenerated and removed by other means, sometimes illegal.

U.S. Pat. US-A-4 179 019 is a known device for regenerating used lubricating oils. The document assumes that large quantities of lubricating oil are poured out after use, especially in automobile repair shops, where there is a problem with removing large quantities of used engine oil. If these oils were to be recovered, they would have to be collected and transported in closed drums to the oil manufacturer, where large industrial oil processing plants are available. These costs do not give much incentives to a motor vehicle repair shop, petrol station or other oil users to save oil. U.S. Pat. A-4 179 019, in order to improve the regeneration of used lubricating oils, proposes a device consisting of pumps, filters, heat exchangers and a vacuum evaporator unit, which are located in a mobile body. In this way, individual workshops or service stations or other oil users can own the oil processing plant themselves, so that the regeneration of the used oil is to become considerably more attractive.

It follows that this is a small treatment plant that is suitable for home use or a workshop, and it is clear that the plant can only process a small amount of oil in real time, that is, an amount of oil found, for example, in a single a motor of a motor vehicle which is only a few liters, ie a maximum of 5 or 7 liters. Therefore, it is not possible to process a larger amount of oil, because in series with a single filter with a transmittance of up to 5 μιη, only a single filter with a transmittance of up to 0.5 μιη is again included. This significantly reduces the capacity of the device. In addition, in the known apparatus, only oils used in vehicle engines which contain only a few final impurities, such as fuel components or hydrocarbons formed during operation, can be treated. Further or further processing of old oils, especially those which are contaminated by metal chips and the like in industrial plants, is not possible with this device.

US-A-4,352,739 discloses a device for filtering liquids, such liquids that occur when drilling with an oil bath, so that they are cooling liquids. There is described a prior art device comprising three filters, nothing about the nature of these filters. Since only these filters are used, only liquids with a narrow range of particulate contamination can be cleaned, or cleaning is unsatisfactory because the filters become unusable very quickly with a wide range of particulate matter and must be replaced. Furthermore, if metal particles are present, the filters are inevitably clogged very quickly.

U.S. Pat. No. 1,624,385 discloses an apparatus for recovering solids from liquids from very low solids pressure presses. For this purpose, the device is provided with a tank into which contaminated liquid is introduced. Above the screen is a liquid outlet. At the bottom is an extruder, which transports away only the solid particles.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome these drawbacks and to improve the generic design of the oil filtering device so that it can operate on a relatively larger scale, i.e. with a capacity of about 5,000 to 6,000 cubic meters of contaminated liquid per month. , in such a way that they are reusable as lubricating oils. The same applies to coolants and cooling water.

SUMMARY OF THE INVENTION

This problem is solved and the deficiencies of known devices of this kind are largely eliminated by a device for filtering contaminated liquids, in particular oils, waste oils, tar oils, coolants, cooling water and the like, consisting of a filter and pumps pushing the liquid through the filter. a plurality of ultra-fine filters arranged parallel to one another in the flow path are arranged in the filter, and the magnetic filter is provided with switchable magnets for pulling the magnetizable solid particles out of the liquid.

The magnetic filter reduces the load on ultra-fine filters and thus reduces the frequency of cleaning and replacement. Thus, the magnetizable particles, in particular the magnetizable metals, are removed from the old oil beforehand, furthermore, the particles of these white or black metals are removed from the treated oil down to a size of the order of 5 µm.

It has been shown that the additional use of ultrafine filters makes it possible to reduce the content of particles still present in the order of 120 µm and more by a factor of 10 to 20, i.e. down to 5 µm, so that the oils cleaned and treated with the device up to 15 µm, the particle fraction in oils also being reduced by a factor of the order of 20. In one particular experiment, it was shown, for example, that the device according to the invention was able to reduce gravimetric contamination according to ISO / DIS 4405 from 427 mg / l to 26 mg / 1st

The pump is preferably connected upstream of the first filter. Further advantageous embodiments are that ultra-fine filters can be grouped for liquid treatment. This achieves that out of a given number of ultrafine filters, one or more groups may be further used for filtering and the apparatus of the invention may remain in operation even if at least one group of ultrafine filters is removed from the liquid circuit, for example to clean or replace these ultra-fine filters. This contributes to increasing the operating efficiency of the device according to the invention.

The ultrafine filters are preferably designed in such a way that they are provided with a cylindrical shell having a hollow center between which a filter material is arranged between the shell and the shell, these ultrafine filters per se corresponding to the filter part of the filters described for example in German patent application no. 39 38 686 or in German utility model no. 89 13 769, the contents of which are therefore part of the subject-matter of this patent application.

In view of the possible oil leakage during cleaning and replacement of the ultra-fine filters, it is advantageous if the device is equipped with at least one oil-collecting sump, preferably located below the ultra-fine filters.

For efficient cleaning of tar oils, which may also contain sand, it is furthermore advantageous that a heating unit with a flow separator for water vapor is installed upstream of the pump and the power filter.

A further advantageous embodiment consists in that the inlet stage consists of a pre-tank which is equipped with at least one screen. Thus, considerably coarse particles can be removed from the treated oil prior to sedimentation in the upstream tank, which differ substantially from the treated oil by their specific weight, so that the filtering and purification apparatus itself is less loaded.

In a further embodiment of the device according to the invention, the magnetic filter constitutes the input stage of the device, while in the first embodiment according to the invention the additional magnetic filter is located inside the filter device. Downstream of the magnetic filter there is preferably a pump with a lever which, depending on the liquid to be treated, can then be introduced either into the flow heater or into the filter with edges or slits or into the separator. This embodiment makes it possible to clean both oils, old oils or tar oils, as well as coolants or cooling water, the latter coming into the input stage magnetic filter heated after passing through the respective devices. This heated liquid can be cooled to the required temperature by a heat exchanger or cooling unit which is part of the device according to the invention. Analogously, the oils can be heated to the required temperature. By means of a filter with slits and slits or a separator, the oil present in the coolant or cooling water is removed, so that this oil is removed from the liquid to be treated already in the process before the ultrafine filters. Thus, the filtering and purifying equipment itself is avoided. Similarly, metal particles are removed from the oil by cleaning the oils with a magnetic impact device, a large-area filter or a web formed by a nonwoven. As a result, these particles also do not burden the actual filtering and cleaning equipment.

In a further embodiment of the invention, the device comprises a double filter by which the liquid can be optionally switched by switching.

As a result, in the second embodiment of the invention, only one device can be used to efficiently clean oils, possibly coolants and water.

From the viewpoint of controlling the operation of the device according to the invention, it may be advantageous if a sight glass is provided in the inlet and / or outlet and the device is provided with a sampling point. The device is equipped with a flowmeter to check the volume of liquid that has passed.

The solution according to the invention achieves a device that is transportable and can be located at the point of old waste, for example in freight forwarders, bus garages, factories where the oils are used in machines and the like, so that these plants can process the old waste oils independently, without relying on other companies. The same is true for larger motor vehicle repair shops that serve as service stations for other people and exchange oils for their customers.

In addition, the devices according to the invention which are transportable can serve as regional small collection and treatment centers for service stations and small motor vehicle services, for which the actual treatment of old oils is not worthwhile.

This saves overall travel time and transport costs. The cost of the device according to the invention is, in spite of its relatively high capacity and hence relatively high performance in quantitative terms and with respect to both high performance and qualitative terms, that is by a hundred times lower than the cost of a central device. The device according to the invention can be operated considerably more economically than in the case of known large-capacity plants, especially since in this case a high continuous supply of waste oils is not required for economical operation.

Despite the above-mentioned monthly output of the order of 5,000 to 6,000 cubic meters with an investment cost of approximately 150,000 Marks (without heating equipment), the device according to the invention can be adapted to the actual expected volume of waste oils, so It can also be carried out with a lower or higher capacity, and from the standpoint of capacity limitation, an embodiment with ultra-fine filters, which are arranged in parallel in the oil passage path, is also cost effective.

Further advantageous solutions of the device according to the invention are that the inlet and outlet of the pre-tank are located on opposite sides of the screen, the outlet of the pre-tank is equipped with a float and an extruder is provided under the inlet of the pre-tank. with permanent magnets such that the extruder can wipe the accumulated magnetizable coarse particles there and carry them out of the pre-tank.

In addition, it is advantageous if an oil-fired flow heater or an edge-slot filter or a separator for coolants or cooling water is optionally installed downstream of the pump. An electromagnetic shock device and a large-area filter are then preferably provided downstream of the flow heater.

Finally, it is preferable that a heat exchanger or cooling unit is placed downstream of the edge-slotted filter or separator and the device comprises an additional pump.

Overview of the drawings

BRIEF DESCRIPTION OF THE DRAWINGS The invention and its further advantages are further elucidated on the basis of non-limiting examples thereof, which are described on the basis of the accompanying drawings which show in FIG. 1 is a schematic overall view of a first embodiment of an apparatus according to the invention;

FIG. 2, on a larger scale, a slightly more detailed side view of the filter and cleaning apparatus itself;

FIG. 3 shows the filter and cleaning device of FIG. 2 in a front view, partly in section;

FIG. 4 is a schematic overall view of a second embodiment of the device according to the invention;

FIG. 5 is a plan view of a battery of ultra-fine filters from the rear; and in FIG. 6 is a side view of the battery of the ultrafine filters of FIG.

5th

DETAILED DESCRIPTION OF THE INVENTION

The device for filtering contaminated liquids, in particular of old oil, according to the invention consists in a first embodiment, which is shown in FIG. 1, in particular from a pre-tank 1, in which, in particular, larger particles with a significantly higher specific gravity than the filtered liquid can settle. As a rule, the liquid should remain in this pre-tank 1 before being subjected to further processing in the apparatus according to the invention for 24 hours.

The upstream tank 1 is provided with a supply pipe 51 extending below the screen 52. The upstream tank 1 extends up to the situation 52 by the suction nozzle 2, by means of which the liquid is pumped from the upstream tank 1. The screens 52 prevent coarse particles from getting out up to the suction head 2a of the suction nozzle 2 and could be sucked off with the other liquid. The suction head 2a of the suction head 2 is designed as a float, so that the suction head 2a always floats at the liquid level 53 independently of the filling level of the pre-vessel 1 and the suction head 2 only sucks the liquid out of the top layer. In order for the suction head 2a to be able to monitor the liquid level, the suction head 2 is designed to be movable at least in the vertical direction. The suction nozzle 2 can be designed as a telescopic tube 54 for this purpose. Alternatively, it could also be designed as a flexible hose.

In the illustrated embodiment, an extruder 55 is provided below the sieves 52 in the region of the inlet tube 51, provided with permanent magnets 56 on its periphery. These permanent magnets 56 attract magnetizable particles, especially larger particles, which is facilitated by the fluid movement caused by the extruder 55. the introduction of air into the liquid further contributes to this. The particles retained by the permanent magnets 56 are then wiped off by the extruder 55 and thus removed from the pre-tank 1.

In the suction line 2b, which is connected to the suction nozzle 2, a coarse particle pre-filter 57 is provided.

This pre-filter 57 may be followed, for example for the treatment of tar oils, by a heating unit 3 in order to heat the purified tar oils to give them a higher viscosity on the one hand and to expel the water moisture present from the liquid. Heating for this purpose is carried out up to a temperature above 100 degrees C, so that evaporation and thus removal of water.

This is carried out in a flow separator 4 for water vapor which can be connected to the heating unit 3.

This flow separator 4 is followed by its own filter device 6, which consists of an inlet 7, a magnetic filter 8 and a pumping unit 9, which preferably consists of a gear pump having a power of several kilowatts and a pressure of 0.6 bar. The pump assembly 9 is then connected to a power filter 11 known per se, preferably a power filter of the SLE 270 030 type. The power filter 11 is supported by the frame 12. The inlet 13 opens into the power filter 11 from the side - see FIG. 2, while the outlet 14 is located centrally below the power filter 11. Such power filters are known per se.

The hot filtered oil in the power filter 11 is further fed to ultra fine filters 16 which filter out even the finest particles from the heated oil. In conclusion, this oil is then discharged through the outlet line 17 for further or new use.

The magnetic filter 8 is provided with very strong magnets, which can be used to pull magnetizable particles out of the oil flow path. At the top of the magnetic filter 8 is a vent valve 21. The magnetic filter 8 is further provided with an indicator 22. In addition, the magnetic filter 8 is provided with its own switch 23 - see FIG. 3 so that it can be optionally switched on or off.

The terminal box 24 is used for supplying electric current and for connection of the whole device.

A coarse or flushing filter 26 is provided upstream of the pump assembly 9, so that very coarse particles can penetrate into the pump assembly 9 and affect its operation or damage the pump assembly until such particles have been separated in the upstream tank 11. This may be the case for particles which do not differ much by their specific gravity from the specific gravity of the liquid, or if the pre-tank 1 is not used.

In addition, a shut-off flap 8a is provided between the magnetic filter 8 and the pump assembly 9 so that the system can be closed if necessary. In addition, a visor (not shown) can be located at this point to monitor and control the consistency, in particular the turbidity of the liquid compared to the liquid at the outlet, where a similar visor can also be placed.

The liquid cleaned by the power filter 11 is led through a discharge pipe branch 46 to a pair of manifolds 27, 28 and thus to one group of ultrafine filters 16. In this connection, the fluid 29 can be directed to one or the other group of ultrafine filters 16 or into both groups of ultrafine filters 16 simultaneously. The first two alternatives allow the ultra-fine filters 16, which are not currently supplied with liquid, to be replaced during operation of the apparatus, so that the entire apparatus does not have to be decommissioned for this purpose. The liquid enters the individual ultrafine filters 16 through central inlets 31 located on the undersides of the ultrafine filters 16 and again exits the ultrafine filters 16 through side outlets 32 also located on the underside of the ultrafine filters 16 and is then led through the collecting tubes to the main pipe 33 and into The discharge port 34 is further disposed in the discharge port 34.

A closure device may also be provided.

The old oil, but also the purified tar oils are first introduced into the pre-tank 1, where they are allowed to stand for the necessary time, for example for a period of 24 hours, in order to separate larger solid particles. Alternatively, it is also possible to use a plurality of upstream tanks 1 with which the filter device is then optionally connected.

The oil is then pumped from the pre-vessel 1 through the suction nozzle 2. by means of a pumping unit 9 and - in the case of tar oils - it is first introduced into a heating unit 3 where it is heated to a temperature of the order of 100 degrees C so that it can be drained by a flow separator 4. water humidity.

The purified liquid then enters the magnetic filter 8, in which the magnetizable particles are separated. The liquid is then forced through the pump assembly 9 through the power filter 11, where the first filtration takes place. Subsequently, the liquid is forced through ultra-fine filters 16, in which even the finest particles with a size down to the order of 15 μιη are filtered out. After passing through these ultra-fine filters 16, the cleaned oil from the discharge nozzle 34 can be removed for new or reuse and recovery.

In another embodiment shown, the device according to the invention initially consists of a magnetic filter 101 equipped with a self-cleaning device, which thus constitutes a pre-filter into which liquid is fed via gravity line 102. Magnetic pre-filtration takes place in this magnetic filter 101 during which magnetizable particles are separated from the liquid. The coarse iron-containing particles are deposited in the filter cake in such a way that even smaller particles of impurities are separated from the liquid in this way. Once the filter cake storage chamber (not shown) reaches a certain degree of filling, the filter cake is automatically removed from the filter cake chamber.

The device shown in FIG. 4 is useful both for filtering old oil, hydraulic oil and tar oil, and for filtering machine cooling water and machine coolant. When filtering the media of the first group, the fluid arrives at the flow 103 through the inlet 105 to the flow heater 106 when the lever 104 is positioned at the pump 103. The pump 103, at a pressure of 4-5 bar, withdraws the liquid which has been pre-cleaned by the magnetic filter 101. under a magnetic filter 101 which serves as a storage tank. The flow heater 106 has a heating capacity of 84.6 kW in order to heat the liquid to 80 degrees C at a flow rate of 2 cubic meters per hour. By means of the instantaneous water heater 106, on the one hand, a higher viscosity of the purified oils is achieved, on the other hand the water and moisture present are also expelled from the liquid. The instantaneous heater 106 is provided with a pressure relief valve and a temperature controller to prevent overheating of the liquid. This flow heater 106 is followed by an electromagnetic shock device 107 by which it agglomerates fine metal particles. A mechanical cleaning stage 108 is arranged downstream of the electromagnetic impact device 107. It is a large-area filter or a wide-bed filter. In this mechanical cleaning step 108, agglomerated particles as well as particles of abrasion, sludge, carbon black and the like are deposited from which the filter cake is formed. The flow rate is preferably 220 rpm. However, in large plants this flow rate may also be 400 or 600 rpm. At the end 109 of the filter zone 110, the particles forming said filter cake 110 are discharged almost dry from the web by means of a continuous web (not shown).

The pre-filtered liquid is further conveyed by the second pump 111 to the double filter 112. Due to this double filter 112, the filters of which can be optionally selected, prevent any coarser particles still present in the ultrafine filtration device. The double filter 112 may be a ceramic filter or a paperboard filter. However, a stainless steel screen having a pore size of 3-5 µm can also be used.

It can be directly connected to the double filter 112 or can be connected to the double filter 112 by a flow meter 113. This flow meter 113 can be equipped with a continuous or daily counter. In this way, the cleaned amount can be monitored when cleaning old oils. The filtered liquid then enters the ultrafine cleaning device 114 where it is fed to the ultrafine filters 115. These ultrafine filters 115 filter out even the smallest particles from the liquid, and the fluid exits these ultrafine filters 115 through the outlet 116 from which the finely filtered medium is routed into an empty space (not shown). tanks intended for cleaned medium, especially oils. In particular, metal residues such as lead, zinc and aluminum, as well as soot, emulsions and water, are filtered to a maximum extent by the ultrafine cleaning device 114.

The device according to the invention further comprises a switch box 117 in which all the switching operations are carried out, which also includes alarm signals and overload indicators and which, if necessary, stops or disconnects the entire device.

If the device shown in FIG. 4, used to purify coolants or cooling water, then the medium, especially if high water fractions are to be separated, having a temperature of approximately 50 to 70 degrees C after passing through large systems, passes in the same way as oils through a magnetic filter 101. by the pump 103 not to the flow heater 106 but after the lever 104 has been moved to the edge and slot filter 118. Using this filter 118, oils are separated from water and abrasion particles. The accumulated dirt and solid sludge are removed by a valve (not shown) at the bottom of the filter 118. A separator may also be used instead of the edge and slot filter 118.

After this filtration, the liquid medium enters the heat exchanger or cooling unit 119, where it is cooled to approximately 20 degrees C. The cooling unit 119 is placed directly downstream of the ultra fine cleaning device 114, or after the lever 120 is moved, cleaning via a second pump 111, a double filter 112 and optionally a flow meter 113. The adjustment of the lever 120 is effected by means of a switch box 117.

All components 101 to 120 are mounted on a common base (not shown) that can be reinforced with a steel frame. The entire system can be made mobile or stationary16, including all necessary pipes, connections and fittings. Only the power and liquid inlets and outlets are to be installed at the application site.

An embodiment of the ultrafine filters 201 shown in FIG. 5 and 6 is applicable as for the ultra-fine filters 16 of FIG. 1 to 3, and for the ultra-fine filters 115 of FIG. The ultrafine filtration device comprises an ultrafine filter battery 202 which, in the illustrated embodiment, includes three mutually spaced units 203, 204, 205 that are constructed of ultrafine filters 201. Below the battery 202 is a tank 206 for storing the cleaned media. The heated or cooled medium is fed to the individual units 203, 204. 205 via an inlet 207 with manifold tubes 208. In each manifold 208, shut-off valves 209 are provided. Thus, the individual units 203, 204, 205 can be taken out of operation to ultra fine filters 201 could be replaced. The ultrafine filter 201 consists of a housing 210 with a lid and a quick-release fastener. An inlet with a pressure gauge 211 opens into the housing 210. Between the shut-off valve 209 and the pressure gauge 211, a sludge outlet 212 for sludge and abrasion particles is disposed. After cleaning in the ultra-fine filter 201, the cleaned medium arrives at the outlet 213, which is preferably provided with a non-return valve. From this outlet 213, the medium is led either to the illustrated tank 206 or also to a conduit through which it is directed to a new or reuse location.

PATENT CLAIMS

Claims (3)

1/5 Apparatus for filtering contaminated liquids, in particular oils, waste oils, tar oils, coolants, cooling water and the like, consisting of a filter and pumps (9, 103) for transferring liquid therethrough, downstream of the power filter (11, 108) a plurality of ultra fine filters (16, 115, 201) parallel to each other are provided in the flow path, and the magnetic filter (8, 101) is provided with switchable magnets for pulling the magnetizable solid particles out of the liquid. 2/5 CM sO Q9 fX fX rnn m Device according to claim 1, characterized in that the pump (9) is upstream of the power filter (11). Apparatus according to claim 1 or 2, characterized in that the ultra-fine filters (16, 201) can be grouped into the liquid treatment. Apparatus according to one of claims 1 to 3, characterized in that the ultra-fine filters (16, 115, 201) consist of a cylindrical shell with a hollow center and a filter material is placed between the shell and the center. Device according to one of the preceding claims, characterized in that the inlet stage is formed by a pre-tank (1), which is equipped with at least one screen (52). Apparatus according to claim 5, characterized in that the inlet (51) to the upstream tank (1) and the outlet (2, 2a) from the upstream tank (1) are located on opposite sides of the screen (52). Device according to claim 5 or 6, characterized in that the outlet (2, 2a) of the upstream tank (1) is provided with a float. Device according to one of Claims 5 to 7, characterized in that an extruder (55) is arranged below the inlet (51) to the upstream tank (I). Apparatus according to claim 8, characterized in that the extruder (55) is provided with permanent magnet jaws (56) so that the extruder (55) can wipe the accumulated magnetizable coarse particles there and remove the particles from the upstream tank (1). Device according to one of the preceding claims, characterized in that a heating unit (3) with a flow separator (4) for water vapor is installed upstream of the pump (9) and the first filter (II). Device according to one of Claims 1 to 10, characterized in that the first stage of the device is formed by a magnetic filter (101). Device according to claims 1 to 10, characterized in that the magnetic filter (8) is arranged inside the filter device (6). Apparatus according to claim 11, characterized by a magnetic filter (101) engaged with the lever (104). by the pump (103) Apparatus according to claim 13, characterized in that an oil flow heater (106) or an edge filter and a slot filter or a separator (118) for coolants or cooling water are optionally arranged downstream of the pump (103). Apparatus according to claim 14, characterized in that an electromagnetic impact device (107) and a large-area filter (108, 109) are arranged downstream of the flow heater (106). Apparatus according to claim 14, characterized in that a heat exchanger or cooling unit (119) is arranged downstream of the edge filter and the separator (118). Apparatus according to one of the preceding claims, characterized in that it comprises a further pump (111). Device according to one of the preceding claims, characterized in that it comprises a double filter (112). Device according to one of the preceding claims, characterized in that a sight glass (37) is arranged in the inlet and / or outlet. Device according to one of the preceding claims, characterized in that it is provided with a sampling point. Device according to one of the preceding claims, characterized in that it is equipped with a flow meter (36, 113). Apparatus according to one of the preceding claims, characterized in that it is equipped with an oil sump, in particular under ultra fine filters (16, 115, 201). 3/5 V5 Ό