GB2045103A

GB2045103A - Combined settling and filtering apparatus

Info

Publication number: GB2045103A
Application number: GB8010405A
Authority: GB
Original assignee: IME Srl
Current assignee: IME Srl
Priority date: 1979-03-28
Filing date: 1980-03-27
Publication date: 1980-10-29
Also published as: ES8101398A1; NL8001777A; DE3011352A1; ES490017A0; FR2452306A1

Abstract

A cleaner for fluids in which a first tank (2) having an inlet (19) for a fluid to be cleaned and an outlet communicating with dredging means (14) extending along a bottom wall (6) of the said first tank (2); a second tank (20) provided with exhausting means (32) communicating with a machine which utilizes the cleaned liquid; and an hydraulic circuit interposed between the said two tanks (2-20) and including at least one filtering cartridge (45) which is detachably connected to a conduit (35-38-39) inside the said first tank (2) and is cleanable by means of a flow of fluid under pressure supplied through the said conduit (38) towards the said first tank (2). <IMAGE>

Description

SPECIFICATION Cleaner for fluids, in particular for the separation of solid bodies from coolants for machine tools The present invention relates to a cleaner for fluids, which may be utilized to separate sludges or other suspended materials from any fluid whatever, but is particularly suitable for being used for the separation of solid bodies, for example chips, from coolants for machine tools. The following description relates exclusively to this particular technioal field, without however taking off anything from the generality of the problem.

Normally, the coolant utilized in the machine tools during cutting operations is recovered by means of cleaners which remove the solid bodies suspended therein and supply again the cleaned liquid to the machine tools for being utilized again.

In the coolant recovery plants it is known to utilize cleaners comprising a tank of relatively reduced dimensions, to which the liquid to be treated is supplied. After having been subjected to a partial natural decantation within the said tank, the still dirty liquid is supplied by means of a pump onto a movable filtering band on which the residual solid bodies are deposited. These latter are removed by means of scrapers, whilst the clean liquid which passes through the filtering band is sucked by a pump and conveyed further for being utilized.

The known cleaners described hereinabove have many disadvantages due firstly to their relatively high cost of production and their considerable overall dimensions, and secondly to their poor reliability because of the presence of the movable filtering band whose correct operation requires a continuous maintenance.

The object of the present invention is to provide a cleaner for liquids which will utilize relatively reduced quantities of liquid, will be free from dynamic filtering elements and whose manufacturing costs will be relatively reduced.

This object will be attained according to the present invention by means of a cleaner for fluids, comprising, in combination, a first tank having an inlet for a fluid to be cleaned and an outlet for the solid bodies separated therefrom; dredging means extending along a bottom wall of the said first tank and communicating with the said outlet; a second tank provided with exhausting means arranged to communicate with a machine using the cleaned liquid; and an hydraulic circuit interposed between the said two tanks; the said hydraulic circuit comprising a self-priming pump, a first conduit which connects the said pump to the first tank; a second conduit which connects the said pump to the second tank, and at least one filtering cartridge which is detachably mounted on one end of the said first conduit inside the said first conduit inside the said first tank and is cleanable by means of a flow of fluid supplied through the said first conduit towards the first tank.

Further characteristics and advantages of the present invention will be apparent from the following description with reference to the accompanying drawings showing, by way of non limitative exam pie, an embodiment of the invention and in which: Figure 1 is an axial section of the cleaner accord ing to the teachings of the present invention, Figure 2 is a section along line Il-Il of Figure 1 Figure 3 is a section along line Ill-Ill of Figure 2, and Figure 4 is an axial section of a variant of the detail shown in Figure 3.

Figure 1 shows a cleaner 1 apt to receive a dirty liquid, in particular a coolant utilized by one or more machine tools and to return it in a cleaner condition and ready to be utilized again.

The cleaner 1 comprises an elongated decantation tank 2 which, a shown in Figure 2, comprises two vertical side walls 3 and 4 connected, at the upper part, to a horizontal upper wall 5. At their lower part, the said walls 3 and 4 are connected to the side edges of a bottom wall indicated generally by reference numeral 6 and comprising two walls 7 inclined towards one another and extending downwards from the lower edges of the walls 3 and 4 and a C-shaped central element 8 having its concavity turned upwards. Element 8 comprises a horizontal core 9 and two vertical tabs 10 whose upper edges are rigidly connected to the lower edges of the walls 7.

Fixed within the seating defined by the element 8 is an open-top box 11 comprising two vertical sidewalls 12 which support the axes of a plurality of rollers 13 about which a conveyor belt dredging device 14 is wound.

As shown in Figure 1, the tank 2 is closed at one end by a vertical wall 15 and communicates, at the other end, with a tubular extension 16 inclined upwards, whose end section 17 is inclined vertically downwards and opens above a removable container 18.

As shown in Figure 2, one of the walls 3 and 4 (the wall 3 in the example shown) is provided at its upper part with a inlet slit 19 through which the fluid to be cleaned is supplied to the interior of the tank 2.

As shown in Figure 1, the dredging device 14 extends all along the bottom wall 6 and all along the inclined wall of the tubular extension 16 and terminates in the region of the end section 17 of the said extension.

As shown, in particular, in Figure 1,theupperwall 5 of the tank 2 forms the bottom wall of a storage tank 20 superimposed on the tank 2 and defined by two vertical sidewalls 21 and 22, two vertical end walls 23 and 24 and a horizontal upper wall 25 which in some cases may be omitted. The two tanks 2 and 20 communicate with one another through an overflow conduit 26 which is mounted through a hole 27 formed in the wall 5 and extends upwardly within the tank 20 till it reaches a determined level.

Formed through the wall 21 is a hole 28 disposed at a level lower than that of the upper end of the conduit 26 and through which the tank 20 communicates with an inlet conduit 29 (Figure 2) of a suction pump 30 actuated by a motor 31 and connected, through an outlet conduit 32, to one or more machines (not shown).

As shown in Figure 1, the tanks 2 and 20 communi cate with one another not only through the conduit 26, but also through a circuit indicated generally by reference numeral 33 and comprising a self-priming suction pump 34 which usually is of the reversible type and is disposed on a portion of the wall 5 which extends outside the tank 20. Pump 34 has a capacity higher than that of the pump 30 and is interposed between two conduits 35 and 36, the first of which penetrates into the tank 2, whilst the second penetrates into the tank 20 and terminates with a draft pipe 37 which normally is disposed at a lower lever than the upper end of the conduit 26.

Conduit 35 has, inside the tank 2, an elbow to which a horizontal pipe 39 is connected which, as shown, in particular, in Figure 3, is provided with a first outer threaded section 40 dispose near the elbow 38, a second outer threaded section 51 disposed at its free end, and a plurality of radial holes 42 formed on the section comprised between the threaded sections 40 and 41.

Threaded section 40 is engaged by a nut 40 forming, with the interposition of a washer or annularflange 44, an end support of an extractible tubular cartridge 45 which is axially locked on the pipe 39 in contact with the flange 44 by means of a second washer or flange 46 and a cap nut 47 mounted on the threaded section 41.

As shown in Figure 5, cartridge 45 comprises a cylindrical wall 48 having a plurality of radial through holes 49 and coated externally by means of a net 50 formed by a metal having holes 51 which are substantially square in shape. The opposed ends of the net 48 are bent inwardly and are in contact with the inner surface of the wall 48 to which they are connected preferably by welding.

As shown in Figure 1, the cleaner 1 comprises a source of air under pressure 52, which communivates with the interior of the pipe 39 by means of a conduit 53 inserted onto the elbow 38.

In use, the dirty liquid is supplied into the interior of the tank 2 through the lateral slit 19 and undergoes a first cleaning by natural decantation, since the heavier solid bodies suspended in it deposit in a very short time either directly onto the dredging device 14 or onto the inclined walls 7 to successively slide onto the dredging device 14.

The relatively dirty liquid which is present inside the tank 2 is sucked by the pump 34 through the cartridge 45, the pipe 39 and the conduit 35 and is supplied into the tank 20 through the conduit 36 and the draft pipe 37.

During the passage through the net 50 the liquid is cleaned from the remaining solid bodies which precipitate onto the dredging device 14 disposed immediately below the cartridge 45; accordingly, the liquid which reaches the tank 20 may be sucked by the pump and conveyed to the machine which utilizes it.

As regards the net 50 it should be pointed out that, as said before, the holes 51 of this net are square in shape, and not circular as usually, in order to allow, the filtering capacity being equal, a largerfiowof liquid through the cartridge 45.

In spite of the fact that a large quantity of the solid bodies separated by the cartridge 45 precipitate immediately onto the dredging device 14, after a certain period of time some of the holes 51 result in being clogged and require the cartridge 45 to be cleaned. This cleaning operation may be rendered automatic by means of a timing circuit (not shown) and may take place in two different ways.

According to a first way of operation, pump 34 is stopped and air under pressure is supplied in countercurrent into the pipe 39 through the conduit 53. This air, flowing through the holes 42 of the pipe 39 and through the holes 49 of the wall 48, reaches the net 50, thus clearing the clogged holes 51.

In relation to what has been described hereinabove it should be pointed out that the operation of blowing in air into the pipe 39 has a considerable importance as regards the operation of the pump 34.

In fact, during the cleaning of the cartridge 45, conduit 35 remains full and only the cartridge 45 is emptied, so that at the end of the cleaning operation, the pump 34, which is a self-priming pump, may start operating again in an extremely shorttime.

According to another way of operation, the direction of rotation of the pump 34 is inverted and the cartridge 45 is cleaned by supplying in countercurrent into the cartridge itself a certain quantity of clean liquid taken from the tank 20. It is clear that in case the cleaning operation is carried out in this way, the source 52 and the conduit 53 may be omitted.

It is obvious that after a certain number of cleaning operations the cartridge 45 has to be substituted.

This substitution is carried out in an extremely simple way by unscrewing the nut 47, extracting the exhausted cartridge 45 after removal of the washer 46 and mounting a new cartridge 45 which is fixed onto the pipe 39 by means of the washer 46 and the nut 47.

Since during the cleaning of the cartridge 45 pump 34 either does not operate at all or takes in liquid from the tank 20 together with the pump 32, the tank 20 acts as a plenum chamber to prevent stopping the supply of cleaned liquid to the machine which utilizes it. Accordingly, tank 20 must always contain a quantity of liquid at least equal to the quantity of liquid sucked by the pump 30 during the time required for cleaning the cartridge 45. The foregoing ensured by the presence of the overflow conduit 26 and by the fact that, as said before, the capacity of the pump 34 is greater than that of the pump 30.

Consequently, in normal operating conditions, the level of the liquid within the tank 20 is always that of the upper end of the conduit 26 and the excess of liquid supplied by the pump 34 returns to the tank 2 through the conduit 26.

In relation to the foregoing statements it is suitable to point out that the continuous transfer of cleaned liquid from the tank 20 to the tank 2 is rendered extremely simple by the superimposed arrangement of the tanks 20 and 2, which ensures also a considerable reduction of the overall dimensions with respect to those of any other arrangement.

The varint shown in Figure 4 relates to a filtering cartridge indicated generally by reference numeral 54 and comprising a body 55, substantially cylindrical in shape, formed by two end walls 56 and 57 provided near their outer peripheries with holes 58 uniformly spaced and traversed by tie rods 59 which, by means of end nuts 60, clamp the walls 56 and 57 to one another and against a substantially cylindrical filtering wall 61 disposed coaxially with respect to the walls 56 and 57. Wall 61 is preferably formed by a metal sheet wound cylindrically and having a plurality of substantially square holes (not shown), or by a perforated flexible sheath.

Each wall 56 and 57 is provided, on its own surface facing the other wall, with an annular groove 62 having lodged therein, in addition to one of the ends of the filtering wall 61, one of the ends of a first cylindrical net 63 with relatively large meshes, disposed in contact with the inner surface of the filtering wall 61 and acting as a support and a stiffening element for the said inner surface, and one of the ends of a second cylindrical net 64 with relatively large meshes, disposed outside the filtering wall 61 and coaxially with this latter and acting as a a protection net.

The wall 57 acts as closure cover for a cup-shaped body 65 arranged within the wall 61 and coaxial with it, which body comprises a cylindrical wall 66 rigidly connected on one hand to the inner surface of the wall 57 and on the other hand to a closure wall 67 parallel to and facing the wall 56. The cup-shaped body 65 divides the inner space of the body 55 into two chambers, of which the first, indicated by reference numeral 68, is substantially cylindrical in shape and completely separated from the outer ambient, while the second, indicated by reference numeral 69, is substantially U-shaped in axial crossection and communicates with the outside through the wall 61.

Chamber 69 is limited externally by the walls 56 and 57 and by the wall 61 and internally by the cup-shaped body 65 and communicates, through an axial hole 70 formed through the wall 3, with a conduit 71 extending axially outwards from the body 55 and connected to the point 58.

In the filtering cartridge 1 described hereinabove, the presence of the cup-shaped body 65, by considerably limiting the free space inside the filtering wall 61, not only ensures a perfect suction through the wall 61, but, above all, allows to carry out the cyclic cleaning of this latter by means of a fluid supplied through the conduit 53 under a relatively reduced pressure.

Obviously, without varying the principle of the present invention, numerous modifications and variations can be made to the filtering cartridge 1 described herein by way of non limitative example, without departing from the scope of the present invention.

Claims

1. Acleanerforfluids, particularly for the separa- tion of solid bodies from liquids, characterized in that it comprises in combination: a first tank having an inlet for a fluid to be cleaned and an outlet for the solid bodies separated therefrom; dredging means extending along a bottom wall of the said first tank and communicating with the said outlet; a second tank provided with exhausting means arranged to communicate with a machine which utilizes the cleaned liquid; and an hydraulic circuit interposed between the said two tanks; the said hydraulic circuit comprising a self-priming pump, a first conduit which connects the said pump to the first tank; a second conduit which connects the said pump to the second tank, and at least one filtering cartridge which is detachably mounted on one end of the said first conduit inside the said first tank and is cleanable by means of a flow of fluid supplied through the said first conduit towards the said first tank.

2. A cleaner as claimed in Claim 1, characterized in that the said second tank is provided with an "overflow" conduit communicating with the said first tank.

3. A cleaner as claimed in Claim 2, characterized in that the said second tank is disposed directly above the said first tank.

4. A cleaner as claimed in Claim 2 or 3, characterized in that the said pump has a capacity higher than that of the suction means connected to the said second tank.

5. A cleaner as claimed in any of the preceding Claims, characterized in that the said filtering cartridge comprises a perforated cylindrical wall arranged coaxiallywith a perforated end section of the first conduit, a filtering net which covers the outer surface of the said cylindrical wall, and a first and a second annular end flange facing the opposed ends of the said cylindrical wall; the said perforated end section of the said first conduit being provided with axial shoulder means for the said first flange, and a threaded end section projecting outwards from the said second flange; and a locking nut being mounted on the said threaded section for axially locking the cartridge against the said shoulder means.

6. A cleaner as claimed in Claim 5, characterized in that the said filtering net is formed by a metal plate provided with a plurality of substantially square holes.

7. A cleaner as claimed in any of the Claims 1 to 4, characterized in that the said filering cartridge comprises a substantially cylindrical filtering wall detachably mounted between a first and a second end wall, the said first end wall being traversed by the said first conduit, and this latter communicating with the said filtering wall through an inner chamber having a substantially U-shaped axial cross-section with the concavity turned towards the said second end wall.

8. A cleaner as claimed in Claim 7, characterized in that the said inner chamber extends between the said two end walls and is limited externally by the said filtering wall and internally by a cup-shaped body closed by the said second wall and extending from this latter towards the said first wall coaxially with respect to the said filtering wall.

9. A cleaner as claimed in Claims 7 or 8, characterized in that the said cartridge further comprises cylindrical stiffening net disposed between the said two end walls in contact with the inner surface of the said filtering wall.

10. A cleaner as claimed in any of the Claims 7,8 and 9, characterized in that the said cartridge further comprises a protection net disposed between the said two end walls outside the outer surface of the said filtering wall.

11. A cleaner as claimed in any of the preceding Claims, characterized in that the said self-priming pump is of the reversible type, the fluid utilized for cleaning the cartridge being a cleaned fluid taken from the second tank by means of the said pump and supplied to the said first conduit.

12. A cleaner as claimed in any of the Claims from 1 to 10, characterized in that the said fluid utilized for cleaning the said cartridge is air under pressure, the said cleaner comprising a source for the said air under pressure and a conduit which connects the said source to a point of the said conduit situated immediately upstream the said cartridge.

13. A cleaner as claimed in any of the preceding Claims, characterized in that the said first tank has a bottom wall comprising, centrally, an elongated seating having lodged therein the said dredging means.

14. A cleaner as claimed in Claim 13, characterized in that the said dredging means comprise an outer supporting box having a substantially Ushaped cross-section and accomodated inside the said seating, and elt conveyer means extending along and supported by the said box.

15. A cleaner for fluids substantially as described with reference to accompanying drawings.