The present invention concerns a separator means as defined in the preamble to Claim 1.

In various plants or installations, such as vehicle washing premises, service stations, fire sta¬ tions, industrial plants, oil refineries, etc., the sink holes receive, admixed with the effluent, various oils, acids and chemicals, which constitute a pollution problem. Therefore, such effluents cannot be allowed to flow into the sewer network or into the ambient envi¬ ronment as such: they must be purified in waste water treatment apparatus especially arranged to take care of their treatment. However, separate waste water purify¬ ing plants are not usually constructed in connection with those objects presenting a comparatively light waste loading in which purification of effluent liquids would be required but in the case of which the waste disposal provisions do not demand a purifying plant proper to be built, the reason being that such plants are costly. In the art no such inexpensive and effi¬ cient solution to the problem is known which would be usable in said instances towards effluent purification. Nowadays, however, increased attention could be paid to the reduction of environment-burdening emissions if only a means were available which is simple enough and cheap enough.

In prior art is known, through the reference WO 83/01268, a sink hole filter comprising a holder ring suspended in the upper part of the sink hole, below the sink hole grating. This holder ring supports a cup- resembling coarse filter, e.g. a wire basket, serving to separate in a first step from the effluent any par- ticulate impurities, such as gravel, leaves, etc. Below the coarse filter, a fine-filter bag is suspended from the holder ring, which is made of elastic, and water-

permeable, fabric or fibrous material.

The problem with a bag-like filter of prior art like this is that it presents only one filtering wall through which the effluent flows and, consequently, its filtering power is low. This device is intended, in the first place, to be used in common outdoor rain water sinks, and it is not appropriate for use in heavy in¬ dustrial applications, e.g. in connection with car- washing areas, service stations, fire stations, indust- rial plants, oil refineries, harbours, ships, oil dril¬ ling rigs, etc. It is a further problem that the bag¬ like filter is awkward to handle. It may easily happen that the bag comes free of its holder ring and falls down in the sink hole. The object of the invention is to eliminate the drawbacks mentioned in the foregoing.

It is a specific object of the invention, to provide an inexpensive and easy-to-use separator means which efficiently precludes access of oils, acids and other harmful chemicals into the sewer.

It is moreover an object of the invention, to provide a means which can be installed as an ancillary device in any existing sink hole.

The means of the invention is characterized by that which is set forth in Claim 1.

The separator means of the invention comprises a frame which is suspended in the upper part of the sink hole, and a filter which is disposed to be borne by said frame and which contains adsorbent material which is problem waste-retaining and water-repellent and water-permeable, for filtering the problem waste out of the effluent.

As taught by the invention, the filter com¬ prises a plurality of adsorbent material layers and a plurality of supporting members for carrying the ad¬ sorbent material layers one above the other and spaced by a distance, and the frame is arranged to receive and

carry a predetermined number of supporting members and adsorbent material layers.

The adsorbent material layers placed one above the other and spaced to lie at a distance from each other allow the water to pass through rapidly without causing any water to accumulate on top of the filter. The number of adsorbent material layers is selected to be appropriate in view of the particular application and of the degree of filtering which is desired. The lowermost adsorbent material layer in the structure of filtering layers, which obviously will be soiled least of all, may be used to indicate the need of changing filter, this being ascertained by observing, from time to time, the soiling of the lowermost adsorbent mate- rial layer. The used adsorbent material may be forward¬ ed to a problem waste treatment installation for ulti¬ mate disposal.

The adsorbent material may be fibrous material, felt or woven fabric made of any plastic material and repelling water, but absorbing in itself liquid hydro¬ carbons, acids and/or chemicals.

In an embodiment of the separator means, the adsorbent material layer is a felt formed of polypropy¬ lene fibres. One particularly suitable felt formed of polypropylene fibres is the material carrying the com¬ mercial name OPEC RP18 (manufactured by OPEC Oil Pollu¬ tion Environmental Control Ltd, England) . OPEC RP18 is particularly advantageous for use as adsorbent material in this connection because it is able to retain in it- self liquid hydrocarbons, acids and various chemicals and is, at the same time, water-repellent and water- permeable. OPEC RP18 is able to take up various liquid substances more than 20 times its own weight. The fol¬ lowing substances may be mentioned as examples of sub- stances which the OPEC RP18 material is able to adsorb: oil, petrol, diesel oil, ethylene acetate, ethyl alco¬ hol, trichloroethylene, sodium hydroxide, acetic acid.

nitric acid, oxalic acid, phosphoric acid, tannic acid, benzoic acid, formic acid, acrylic acid, adipic acid, xylene, potassium, chlorotoluene, trichloroethylene, carbon tetrachloride, benzylalcohol, ethyl acetate, mineral oil, potassium chloride. The testing institute Lloyd's Register of Shipping has tested the material's absorbing capacity, concerning which there are test reports LDS 800779/1 and LDS 800779/2. OPEC RP18 mate¬ rial is available in the form of mats with thickness 4.5 and 9.5 mm.

In an embodiment of the separator means, the frame comprises a substantially vertical, coherently unbroken side wall, fitted to reside within the sink hole, and a rack for carrying the filter. The filter is accommodated inside the housing formed by the side wall.

In an embodiment of the separator means, the adsorbent material layers and the supporting members are stacked in alternation loose from each other and upon each other, to be borne by the rack. The support¬ ing member may for instance be a substantially rigid grating. The rack may also consist of a net, grating or the like, provided in the lower part of the frame.

In an embodiment of the separator means, the adsorbent material layer and the supporting member are joined to each other to constitute a rigid and compact, plate-like filter cell, and the supporting member com¬ prises two substantially planar, rigid supporting nets with the adsorbent material layer arranged therebe- tween, and a fixing member for joining the supporting nets and the adsorbent material layer, and the filter comprises a plurality of filter cells. The filter cells are arranged substantially horizontally above each other and spaced from each other. The cell displays at least so much rigidity that it will, when supported by its margins, withstand the load caused by the water flowing through, plus the weight of the waste substan-

ces which it takes up. The adsorbent material layer is easy to install between the supporting nets, and to remove therefrom. When the adsorbent material layer consists of OPEC RP18 mat, which is available in rolls, it is easy enough to arrange to fit the size of the cell, and it is easy to install between the supporting nets. It has been found advantageous to use in the cell, two superimposed courses of OPEC RP18 mat of 4.5 mm thickness. In an embodiment of the separator means, a packing is provided on the rim of the filter cell in order to seal it against the wall.

In an embodiment of the separator means, the means comprises a collecting device, such as a basin or equivalent, suspended to be carried by the frame, above the filter, and disposed to collect solid substances and/or solid objects that are carried into the drain outlet, in order to prevent their entering the filter, while causing no obstruction to the onward flow of liquid. It becomes possible with such a collecting device to collect e.g. tools and small apparatus com¬ ponents which happen to fall into the drain; it would be difficult otherwise to recover them quickly for re¬ use. The collecting device also serves as sand separa- tor.

The separator means can be implemented in a great variety of different configurations to fit sink holes of different shapes. When the sink hole has a circular cross section, the walls of the frame will form a cylindrical tube and the filter will be round.

When the cross section of the sink hole is a square, the walls of the frame will form a square tube, and the filter will be shaped like a square. When the sink hole has the shape of an elongated rectangle, several sepa- rator means can be accommodated therein side by side, and the frame walls of each separator means will form a tube with rectangular cross section, and the filter

will be rectangular in shape.

In the following the invention is described in detail, referring to the attached drawing, wherein:-

Fig. 1 presents, schematically and in eleva- tional view, an embodiment of the means of the inven¬ tion;

Fig. 2 presents, schematically and in eleva¬ tional view, another embodiment of the means of the invention; Fig. 3 presents, in section, a detail of

Fig. 2; and

Figs 4, 5 and 6 present, in top view, three separator means with different shapes.

In Fig. 1 is depicted a separator means for separating problem waste from waste water. Here, the separator means has been installed in conjunction with a round sink hole, in the upper part thereof. The sink hole consists of a depression or chute covered by a cover grating 12 or equivalent designed to withstand loads. Apertures 13 are provided in the cover 12, through which said fluids can enter the drain chute. The separator means is disposed immediately under the drain cover, in its vicinity. The separator means com¬ prises a frame 1, suspended in the upper part of the sink hole e.g. by means of a flange 14 extending over the rim of the sink hole. The separator means further comprises a filter 2, suspended to be carried by the frame 1. The active, filtering part of the filter 2 is an adsorbent material 3, of which the properties in- elude retention of problem waste, while it is at the same time water-repellent and water-permeable in order to filter the problem waste out from the effluent.

The filter 2 comprises several adsorbent mate¬ rial layers 3, their number being five in the present embodiment. The filter 2 further comprises several sup¬ porting members 4 serving as spacers and also as sup¬ ports to carry the adsorbent material layers 3 one

above the other and mutually spaced by a distance. The vertical dimension of the frame 1 has been selected such that it is able to receive in itself and to carry the desired number of supporting members 4 and adsorb- ent material layers 3. The number of adsorbent material layers 3 is selected specifically for each application to correspond to the desired grade of separation; the number of layers, in its turn, determines the number of supporting members 4 required. The substantially vertical, continuous and unbroken side wall 5 of the frame 1 is fitted inside the sink hole. In the lower part of the frame 1 is pro¬ vided a rack 6 for carrying the filter 2. In the embodiment of Fig. 1, the rack 6 is a grating in the lower part of the frame 1. If the frame is made, e.g. of plastic by vacuum moulding, the rack grating 6 may be a plastic moulding integral with the frame 1. The sup¬ porting member 4, too, is here a substantially rigid grating made of plastic material. The support grating 4 is so disposed that, placed horizontally in the frame 1, it will in the horizontal direction fill the entire region defined within itself by the side wall 5. Like¬ wise, the adsorbent material layer 3 extends horizon¬ tally inside the frame 1 over the whole internal cross section area.

In Fig. 1, each supporting member 4 is one integral piece of thin-walled plastic formed in a way that endows it with requisite rigidity. Through aper¬ tures 15 in the support grating, divided over the whole area of the support grating, the water can run down¬ ward.

The adsorbent material layer 3 consists of felt produced of polypropylene fibre. The adsorbent material layer 3 consists of a material known by the commercial name OPEC RP18 (manufactured by OPEC Oil Pollution Environmental Control Ltd, England) . In the embodiment of Fig. 1 the felt course has a thickness of 9.5 mm.

The adsorbent material layers 3 and the support gratings 4 are stacked in alternation, separate from each other, horizontally upon each other to be borne by the support grating 6, thereby producing a multi-layer filter 2. The support gratings 4 keep the adsorbent material layers 3 apart. This serves the purpose of enhancing the water flow through the filter 2. The water will pass rapidly through such a filter 2, and the filtering capacity of the filter will be excellent. The separator means is easy to install in existing sink holes.

The separator means also includes a collecting means 11 suspended to be borne by the frame 1 and oper¬ ating according to the principle of an overflow basin. The purpose of the collecting means 11 is to collect any solid matter and/or solid objects entering the drain aperture, such as tools, in order to prevent them from passing farther into the sink hole. Here, the col¬ lecting means 11 is a circular basin suspended by a flange from the frame 1 and provided with apertures 16 in its side walls through which the effluent can pass further into the filter located therebelow. Sand, and other solid matter, will settle to the bottom of this basin and cannot go further to the filter 2. Fig. 2 depicts a separator means which has been inserted in the sink hole of the vehicle-washing point at a service station. Sink holes at a car-washing point are usually shaped to have an elongated rectangular cross section. In an application like this, not only sand and clay may be carried with the water into the sink hole, but on the side thereof also various subs¬ tances such as petrol, lubricating oil, diesel oil, solvents, detergents, and other chemicals. In addition, fitting work is usually carried out close to the sink hole, in connection of which tools and apparatus com¬ ponents are handled which may fall down into the sink hole.

The separator means comprises a collecting basin 11. This has in its centre an aperture 18, cover¬ ed with a hat 17, through which the liquid can flow, running over the border flanges 19 of said aperture and further downward to the filter 2. The border flanges 19, the bottom 20 of the basin and its vertical walls 21 cooperate to prevent solid matter from going along with the effluent.

Furthermore, the separator means comprises a filter 2, carried by the frame 1 directly under the collecting means 11 in like manner as in the embodiment of Fig. 1. The frame 1 is made of sheet steel, e.g. of stainless steel sheet. In the lower part of the verti¬ cal side walls 5 a supporting flange 6 has been provid- ed to carry the filter.

In the embodiment of Fig. 2 the adsorbent ma¬ terial layer 3 and the supporting member 4 are joined to constitute a compact, plate-like filter cell 7. The filter 2 comprises five filter cells 7 in this in- stance. The filter cells 7 are separate from each other and they are arranged substantially horizontally one above the other and with mutual spacing. The frame 1 is so dimensioned that a predetermined number of filter cells 7 can be placed therein. In some applications one or two filter cells will suffice, while others may re¬ quire using five filter cells or more.

Fig. 3 shows the detail A of Fig. 2, showing part of two filter cells 6. The supporting member 4 comprises here two planar, rigid support nets 8. The support net 8 is made of non-rusting material, such as aluminium or stainless steel. The support net 8 may equally be made of plastic. Between the support nets 8 an adsorbent material layer 3 has been disposed. The support nets 8 and the adsorbent material layer 3 have been joined with each other by the aid of a fixing mem¬ ber 9 to constitute a single, integral and compact, plate-like cell structure. On the margin of the filter

cell 7 a packing 10 is provided for sealing the filter cell against the side wall 5 of the frame 1. In this embodiment the packing 10 is a rubber gasket attached to the edges of both support nets 8 by pressure and presenting a U-shaped portion 23 with inlaid U-shaped metallic bending plate 22, in which the margin of the support net is inserted, and on the other end is pro¬ vided a tubular sealing portion 24, which is urged against the side wall 5 of the frame 1. The filter cells 7 are moreover mutually sepa¬ rated by spacer members 25. In this embodiment, too, the adsorbent material layer 3 consists of two super¬ imposed, 4.5 mm thick felts produced of polypropylene fibre, this felt being known under the commercial name OPEC RP18 (manufactured by OPEC Oil Pollution Environ¬ mental Control Ltd, England) .

Figs 4, 5 and 6 show, in top view, three sepa¬ rator means of different shapes, intended to be used in typical sink holes. The separator means of Fig. 4 is round, and it is appropriate to be used in conjunction with a sink hole having circular cross section, in the case of which the side wall 5 of the frame 1 constitutes a cylindrical or conical tube in which the filter 2 is accommodated.

In Fig. 5 the separator means is square, and it is appropriate to be used in conjunction with a sink hole having square cross section, in the case of which equally the side walls 5 of the frame 1 constitute a square-section tube in which the filter 2 is accommo¬ dated.

In Fig. 6 the separator means has rectangular shape, and it is appropriate to be used in conjunction with a sink hole having a cross section shaped like an elongated rectangle. In the sink hole several separator means can be accommodated side by side, and in this case the side walls 5 of the frame 1 constitute a tube

with rectangular cross section in which the filter 2 is accommodated.

The configuration of the means can of course be modified to fit any particular application. The invention is not exclusively confined to concern the embodiment examples presented in the fore¬ going: numerous modifications can be contemplated with¬ in the scope of the inventive idea defined by the claims.