AT518686B1 - Gravity separator, gravitational separation vessel and method for separating a mixed liquid - Google Patents

Abstract

The invention relates to a method for separating a mixed liquid (2), a gravity separation device (1) and a gravity separation container (3) in which the liquid (2) is fed into a phase separation container (3) via a feed line (12). In the phase separation vessel (3), the mixed liquid (2) is separated into a heavier phase (6) and a lighter phase (7) of the liquid (2) due to the applied gravity, the heavy phase (6) of the liquid (2) in the lower region (13) and the light phase (7) in the upper region (14) of the phase separation container (3) is collected, wherein the liquids (2) of the individual phases (6,7) via lines (4,5) are discharged. The introduction of the supplied mixed liquid takes place approximately at the level (15) of the phase separation surface (16) of the two phases (6,7) of the liquid (2), preferably continuously with low flow velocity, wherein the phase separation surface (16) between a lighter Phase (7) of the liquid (2) and a heavier phase (6) of the liquid (2) is formed, wherein the introduction of the mixed liquid (2) between two horizontal distribution plates (23,24) takes place.

Description

description

GRAVITY SEPARATOR, GRAVITY SEPARATOR, AND METHOD FOR SEPARATING A MIXED LIQUID The invention describes a mixed liquid separation method, a gravity separator, and a gravity separator tank as described in the preambles of claims 1, 6 and 16.

Gravity separation of liquids is known per se and is differentiated into two different separation methods. These include static or passive systems such as settling tanks or decanters as well as dynamic systems under the collective term centrifuges, the solution according to the invention being assigned to the first systems, namely the static systems. In a static system, 2 liquids are separated solely by the action of gravity. The liquids must not form a stable emulsion or solution, although they can be mixed as finely as desired below the emulsion limit. The two phases of the liquid must have at least slightly different densities in order to be able to carry out a separation using gravity.

Usually known from the prior art systems of static gravity separators work in such a way that first distribute the mixed liquid over the entire height of a mostly cylindrical or cuboid container. As a result, the mixture droplets of the mixed liquid have to travel comparatively long distances until they combine with their homogeneous phase, which can be up to several thousand droplet diameters, so that in extreme cases this can take many hours or days with fine distribution. As a result, very large apparatus, in particular containers, of many m ³ volume are required in industrial systems.

From WO 2014/131874 A a device for gravity separation of immiscible liquids with different densities from an emulsion is known, the mixed liquid flowing in a container through an inlet, so that the liquids are separated by the action of gravity by extracting a light phase of the liquid at the top and settling the heaviest liquid below, the two phases flowing out of the tank via corresponding outlets (14, 18). The tank has a partition, the inlet being arranged in a first chamber and the partition having a lower connecting channel between the chambers, so that the heaviest liquid can flow through the connecting channel into the second chamber.

The disadvantage here is that no adjustment options for the formation of the phase separation surface is possible.

From WO 2014/131874 A1, US 3362791 A, US 4 876 079 A, US 3 553 940 A and US 2005/121375 A1 a method and a device for separating two immiscible liquids are known, in which the liquids to be separated are introduced at approximately the height of the phase separation surface.

The disadvantage here is that, however, the liquid to be separated flows unprotected into the container, so that mixing or swirling of the already separated liquids can occur.

The object of the invention is to provide a method for separating a mixed liquid, a gravity separating device and a gravity separating container, in which a rapid and safe separation of mixed liquid takes place solely via the effect of gravity without great technical control effort.

The object of the invention is achieved by a method for separating a mixed liquid, in which the introduction of the mixed liquid supplied is approximately at the level of the phase separating surface of the two phases of the liquid, preferably continuously at a low flow rate, the Phase separation area between 1/14

AT518 686 B1 2018-03-15 Austrian Patent Office see a lighter phase of the liquid and a heavier phase of the liquid, whereby the mixed liquid is introduced between two horizontal distributor plates.

It is advantageous here that the individual droplets of the lighter and heavy phases are introduced in the immediate vicinity of the phase separation surface, so that they only have to travel short distances for deposition in the individual areas, whereas in the prior art the mixed liquid first over the entire area or a large part of the height of the phase separation container is distributed, so that, for example, the droplets of the heavy phase have to travel a very long way in the upper region to the lower deposition region of the heavy phase. Another significant advantage is that the introduction of the mixed liquid in the area of the phase separation area means that the phases which have already been separated are not further mixed, the introduction preferably taking place by a slow, horizontal inflow speed, ie the introduction takes place on a horizontal plane, so that as soon as it flows in due to the action of gravity, the liquid is separated and at the same time the phases are only mixed in the horizontal plane in a very small area around the phase separation surface. It is also advantageous here that suitable horizontal distribution plates effect horizontal horizontal distribution of the inflowing liquid in the phase separation container, so that, for example, the inflowing liquid is distributed over the entire horizontal cross section of the phase separation container.

Another advantage is that by introducing the mixed liquid between two horizontal distributor plates, a horizontal spread of the mixed liquid is achieved in a simple form over the horizontal cross section of the phase separation container. At the same time, further mixing is prevented since the flow velocity of the liquid is substantially reduced by the spreading of the inflowing liquid over a wide cross section. It is also advantageous if one or both distributor plates in a further possible embodiment have holes or bores, in particular also in different sizes and more towards the outer edge of the distributor plates, so that the distributed liquid also emerges over a good part of the surfaces of the distributor plates can. It is also advantageous if in the space between the distributor plates, in particular close to the outer edge, a fine filter material such as Wire, mineral or other fabrics or fibers can be arranged. As the mixed liquid flows through, this develops a coalescence effect on the smallest droplets, which then, in a known manner, then grow together to form larger drops, especially at the crossing points of the fibers, and thus favor the separation. Due to the arrangement near the outer edge, the liquid flowing through is already widely distributed, thereby reducing the speed component and keeping the pressure loss through the filter material very low.

The measures are advantageous in which the heavy phase of the liquid is discharged at the lowest point, in particular a bottom outlet, of the phase separation container via a first line, the line rising from there first with a branching device which is higher than the bottom outlet is arranged, and is connected to the highest point of the phase separation container. This ensures that the removal of the heavy phase due to gravity is carried out without additional pumps or conveying means, in that the heavy phase overflows freely when it reaches the branching device and can then be collected in a lower-lying collecting container. This means that liquid is only removed from the heavy phase if sufficient liquid has already been separated. If a pump or other conveying means is used, there is a risk that liquid which has not yet been completely separated is sucked off.

Also of advantage are the measures that the lighter phase of the liquid in the upper region of the phase separation container is arranged by a further overflow arranged above, but otherwise independently of the branching device, such as e.g. an overflow funnel, is discharged via another line. This ensures that the easy phase

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The measures are advantageous in which the height of the overflow for the heavy phase and thus the height of the phase separation surface is adjusted by adjusting the height of the branching device. It is thereby achieved that for the first time the possibility is created that the phase separating surface can be adjusted to a specific area by simply adjusting the height of the branching device. Once this has been set according to a given density difference between the two phases, the phase separation surface always remains stable at the same altitude due to the self-regulating effect between the two free overflows, regardless of the mixing ratio occurring in the incoming mixed liquid. In a further embodiment it is possible that an arrangement of sensors for recognizing the phase separation area and electrical adjustment means for the branching device enables an automatic adaptation of the phase separation area, in particular in the area of the distributor plates. As a result, the separating device can then additionally react to changes in the density difference and can still be operated stably as long as the previously lower phase remains the heavier of the two liquids. If, for example, the density of one of the phases increases, this causes the phase separating surface to decrease. If the branching device or the overflow of the lower phase is now raised, more liquid of the heavy phase is collected again in the phase separation container, as a result of which the phase separation surface rises.

The measures in which the phase separation surface is set in the region between the upper and lower distributor plate are advantageous. This ensures that the light and heavy phases of the liquid that have already settled are not mixed, so that they can be removed unimpeded and continuously by overflowing, even if new mixed liquid is topped up. This preferably keeps the speed of entry into the container as low as possible, so that the individual phases are separated as soon as they are introduced. Another advantage is that the individual phases, especially droplets, have to travel very short vertical paths to their already separated areas.

Furthermore, the object of the invention is achieved by a gravity separating device in which a phase separating surface is aligned or formed at the same height of an inflow opening for the mixed liquid, two horizontal distributor plates being arranged in the lower region, between which an inflow opening for introducing the mixed liquid is arranged.

It is advantageous here that this means that only in the area of the phase separating surface does mixing take place through the newly introduced mixed liquid and hardly the already separated light and heavy phases are mixed again. A continuous removal of the separated phases is thus possible, these being removed without aids, ie without pumps or other conveying means, by simply overflowing. In this case, a device or system is formed which is operated purely on the basis of the action of gravity, that is to say that the mixed liquid introduced is separated into a light and heavy phase due to the force of gravity, depending on the amount of the divided phases due to the respective overflow a lower and upper overflow edge (eg overflow funnel, branch device) can be removed independently. A continuous supply of new mixed liquid for separation into the phase separation container can thus also be carried out.

However, the designs in which the phase separation container has a bottom outlet at the lowest point, to which a line for removing the heavy phase of the liquid is connected, the line with a branching device and a vent at the highest point of the phase separation container are also advantageous connected is. This ensures that the line is filled independently with the heavy phase of the liquid,

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But it is also an embodiment of advantage in which an overflow in the upper region is arranged in the phase separation container for the light phase of the liquid, which is connected to a line for removing the light phase. This ensures that when the liquid is continuously separated and by collecting the liquid in the upper area, there is a free overflow over the overflow edge, so that the light phase is easily removed without additional aids. This means that there is no risk that the separated phases may mix when the light phase is removed. The height of this upper overflow, for the light phase, is defined in such a way that there is a sufficient height difference from the phase separating surface so that the phase separating surface can move or adjust sufficiently up and down.

However, an embodiment is also advantageous in which two horizontal distributor plates are arranged in the phase separation container in the height range where the position of the phase separation surface is intended and are tightly connected in the middle to the supply line, between the outer edges of which there is a long, narrow inflow opening for introduction the mixed liquid is formed in the container. It is thereby achieved that a flat, horizontal distribution of the inflowing liquid over the cross section of the phase separation container takes place in a simple manner. At the same time, it is advantageously achieved that the inflowing liquid is forced into a horizontal flow, as a result of which mixing of the already separated phases above and below it is largely avoided, since the inflowing liquid spreads out horizontally and thus not into one of the separated phases can flow in downwards or upwards.

An advantage is an embodiment in which the phase separation surface in its height in the area of the inflow opening on the height of the branching device and the balance between the liquid columns of the heavy phase in the riser from the bottom outlet to the branching device on the one hand and the composite liquid column from heavy and overlying light phase inside the phase separation container, on the other hand aligned or adjustable up to the upper overflow. This ensures that mixing of the separated phases is avoided, since freshly introduced mixed liquid flows in precisely in the area that divides the two phases, that is to say that only a thin horizontal layer is present in the phase separation container, in which one which has not yet separated has been mixed Liquid is present, the light phases of the liquid being deposited or collected above this thin layer and below the heavy phase of the liquid. This also shortens the vertical distance of the individual droplets to reach their respective areas.

But it is also an embodiment of advantage in which the separation phase surface is adjustable in height by adjusting the branching device. It is thereby achieved that the height of the phase separating surface can be adjusted in a simple manner in the region of the inflow opening. In this way, unwanted mixing by newly flowing liquid within a zone or area of a phase can be prevented.

However, an embodiment is also advantageous in which the line for the heavy phase and for the ventilation above the branching device / the lower overflow is flexible. This ensures that the height of the branching device can be easily adjusted without having to carry out additional work on the line.

An advantage is an embodiment in which the lines for the light and heavy phase are each connected to a lower collecting container. The result of this is that the system can be operated continuously, since the liquids in the individual phases continuously overflow and are then discharged and collected in a collecting container.

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But it is also an embodiment of advantage in which the upper end of the line for the heavy phase is connected to the free gas space in the uppermost region of the phase separation container which is not completely filled with liquid. It is thereby achieved that when the line is filled with the liquid of the heavy phase, the gases contained in the line simply communicate with the gas space of the phase separation container. The escape of the gases contained in the line neither builds up back pressure, nor can a siphon effect occur, so that the heavy phase can flow freely into the line assigned to it and overflow freely at the branch.

An embodiment is also advantageous in which the three lines leading to and from the branch piece for the heavy phase are at least partially formed from a flexible material or a telescopic tube or the like. It is thereby achieved that a simple height adjustment of the branching device can be carried out, the line being able to adapt accordingly.

In addition, the object of the invention is achieved by a gravity separating container, in which two horizontal distributor plates are arranged in the lower region, between which a wide inflow opening for introducing the mixed liquid is formed, and that when the liquid is poured in, a phase separation surface which is easy Phase separates from the heavy phase, is adjustable or arranged in the area between the two distributor plates.

It is advantageous here that a simple, inexpensive construction of the container is made possible, no tools being required for operation. The precise separation of the mixed liquid takes place solely on the basis of gravity and the split phases are removed by free overflow of an upper (e.g. overflow funnel) and a lower overflow (e.g. the branching device).

But it is also an embodiment of advantage in which the line for the heavy phase is connected to a branching device or a freely positionable overflow, preferably outside the phase separation container. This ensures that an overflow for the removal of the heavy phase of the liquid is created.

However, an embodiment is also advantageous in which the height of the separation phase surface can be adjusted by adjusting the branching device. It is thereby achieved that the phase separation surface can be adjusted by simply adjusting the height of the branching device. The system can thus be set in a simple manner.

Finally, an embodiment is also advantageous in which the phase separation container has a sight glass, which is preferably arranged in the region of the distributor plates. This ensures that the phase separation surface can be easily checked from the outside, and thus the desired setting of the phase separation surface at the height of the distributor plates can be controlled.

The invention is described in more detail below by means of several exemplary embodiments, the invention not being restricted exclusively to this example shown and described.

[0033] The figures show:

1 shows a schematic representation of a gravity separating device;

[0035] FIG. 2 shows a schematic illustration of a further exemplary embodiment of the gravity separation device;

3 shows another embodiment of the gravity separation device, in a schematic representation.

1 to 3 show exemplary embodiments of a gravity separating device 1, the gravitational separating device 1 for separating mixed liquids 2

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The phase separation container 3 or gravity separation container 3 is each provided with a line 4,5 for a heavy phase 6 of the liquid 2 and a light phase 7 of the liquid 2. The lines 4,5 are connected to corresponding collecting containers 8,9 for the separate phases 6,7 of the liquid 2. To remove the separate phases 6, 7 of the liquid 2, the collecting containers 8, 9 are connected to separate removal lines 10, 11.

In the gravity separation device 1, the mixed liquid 2 is fed via a feed line 12 into the phase separation container 3, in particular the gravity separation container 3, the mixed liquid 2 into the heavier phase 6 and the lighter phase 7 in the phase separation container 3 due to the action of gravity the liquid 2 is separated. The heavy phase 6 of the liquid 2 in the lower region 13 and the light phase 7 in the upper region 14 of the phase separation container 3, in particular the gravity separation container 3, is collected or deposited, so that the separated liquids 2 of the individual phases 6, 7 via lines 4.5 are dissipated.

It is essential in the gravity separating device 1 according to the invention that the introduced mixed liquid 2 is introduced approximately at a height 15 of a phase separating surface 16 of the two phases 6, 7 of the liquid 2, preferably continuously at a low flow rate, the phase separating surface 16 between the lighter phase 7 of the liquid 2 and the heavier phase 6 of the liquid 2. According to the exemplary embodiment, the phase separation surface 16 is aligned or formed at the same height 15 of an inflow opening 17 of the feed line 12 for the mixed liquid 2. The heavy phase 6 of the liquid 2 is discharged at the lowest point, in particular a bottom outlet 18, of the phase separation container 3, in particular the gravity separation container 3, via the first line 4, the line 4 from there, that is to say the bottom outlet 18, first rising with a branching device 19 , which is arranged higher than the bottom outlet 18, and is connected to the highest point 20 of the phase separation container 3, in particular the gravity separation container 3. The lighter phase 7 of the liquid 2 is in the upper region 14 of the phase separation container 3 by a further overflow 21 arranged above, but otherwise independently of the branching device 19, such as e.g. an overflow funnel, discharged via the further line 5.

The phase separation container 3 thus has a bottom outlet 18 at the lowest point, at which the line 4 for discharging the heavy phase 6 of the liquid 2 is connected, the line 4 with the branching device 19 and a vent 22 at the highest point 20 of the Phase separation container 3 is connected, whereas for the light phase 7 of the liquid 2 an overflow 21 is arranged in the upper region 14, which is connected to the line 5 for discharging the light phase 7. Furthermore, two horizontal distributor plates 23, 24 are arranged in the lower region 13 in the gravity separation container 3 or phase separation container 3, between which the wide inflow opening 17 for introducing the mixed liquid 2 is formed, and that when the liquid 2 is filled in, a phase separation surface 16, which is the light phase 7 separates from the heavy phase 6, is adjustable or arranged in the area 25 between the two distributor plates 23, 24.

However, so that the phase separation surface 16 is formed in the area 25 between the distributor plates 23, 24, it is necessary, depending on the mixed liquid 2 introduced, to adapt it accordingly. This can be done in the method or gravity separation device 1 according to the invention in such a way that the phase separation surface 16 can be adjusted in height 15 by adjusting the branching device 19, so that by adjusting the height of the branching device 19 a height 26 of the overflow into the collecting container 8 for the heavy phase 6 and consequently the height 15 of the phase separation surface 16 is set, that is to say that the overflow of the heavy phase 6 can be defined by the height adjustment of the branching device 19 and the formation of the phase separation surface 16 can accordingly be adjusted. Thus the phase separation surface 16 is at height 15, e.g. between the two horizontal

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Distributor plates 23, 24, via the height of the branching device 19 and the resulting balance between the liquid columns of the heavy phase 6 in the riser or line 4 from the bottom outlet 18 to the branching device 19 on the one hand and the composite liquid column made of heavy and overlying light phase 6, 7 inside the phase separation container 3, up to the upper overflow 21, on the other hand, aligned or adjustable.

Preferably, two horizontal distributor plates 23, 24 are arranged in the phase separation container 3 in the height range, where the position of the phase separation surface 16 is intended, and connected to the feed line 12, between the outer edges of which a long, narrow inflow opening 17 for introducing the mixed liquid 2 is formed so that little mixing of the already separated phases 6, 7 is caused.

The gravity separation device 1 is operated such that the phase separation container 3 is preferably continuously fed with the mixed liquid 2 via the feed line 12, the inflow opening 17, which is preferably elongated between the distributor plates 23, 24, in the phase separation container 3 between two horizontal, parallel distributor plates 23,24 opens, which directs the inflow of the mixed liquid 2 in the phase separation container 3 in a very wide and flat flow in the horizontal direction. The branching device 19 is adjusted in height 26 such that the phase separation surface 16 is formed between the distribution plates 23, 24, i.e. that the height 15 of the phase separation surface 16 can be adjusted for the first time by adjusting the branching device 19. The branching device 19 can be set, for example, using a simple handwheel and spindle (not shown). A sight glass 27 is arranged on the phase separation container 3 so that the formation of the phase separation surface 16 can be checked. Due to the independent separation of the two phases 6, 7 via the effect of gravity, the heavy phase 6 forms in the lower region 13 and thus fills the line 4. When the line 4 is filled up to the branching device 19, the liquid 2 overflows and is collected in the collecting container 8. So that the line 4 can be filled, the gases located in it must be able to escape, as a result of which the line 4 opens into the gas space in the upper region 14 of the phase separation container 3, thus also preventing an uncontrolled liquid flow and thus mixing of the phases 6 due to the siphon effect , 7 can arise. At the same time, the light phase 7 can run freely in the upper region 14 of the phase separation container 3 via the overflow 21, through which a smooth, flat discharge of the light phase 7 is achieved, and this in turn can be collected in the collecting container 9. Due to the position of the overflow 21, a safe height distance from the heavy phase 6 can be created.

According to the invention, the method or the gravity separation device has two essential parts, namely on the one hand the introduction of the mixed liquid in a slow, horizontal flow exactly at the height 15 of the phase separation surface 16 and on the other hand a self-regulation of the phase position, in particular the phase separation surface 16, by the Use of two free overflow systems, in particular the branch device 19 and the overflow 21 for the two separate phases 6, 7 of the liquid 2. Since the distance for the mixture droplets of the phases 6, 7 in the vertical direction until the homogeneous own phase 6, 7 is reached in the solution according to the invention by now being limited in the area of the phase separation area 16, in particular limited to a few millimeters, gravity separation takes place immediately in the inlet within a few seconds, even during the horizontal distribution within the distributor plates 23, 24. Due to the following very slow flow in the vertical direction in the wide phase separation container 3, there is no further mixing and no entrainment of the other phases 6, 7. The height of the phase separation container 3, in particular the upper region 14 for the light phase 7, serves above all for safety in the case of a slightly fluctuating inflow amount of the mixed liquid 2, e.g. slight pulsation by an appropriate pump. The regulation takes place solely on the basis of the density difference between the materials, in particular phases 6 and 7, but regardless of the mixing ratio. Different mixtures can thus be separated without any problems,

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AT518 686 B1 2018-03-15 Austrian patent office without the phase boundary therefore "crashing" or material of the other phase being carried away, since the equilibrium position of the phase separation surface 16 regulates itself.

The working principle of the gravity separation device is such that the combined static weight of the two liquid columns in the phase separation container 3 from the bottom outlet 18 to the upper overflow 21 in equilibrium with the heavy and therefore shorter liquid column or phase 6 in the line 4 to the overflow in the branching device 19 is.

In order to operate the gravity separating device 1 with different materials and densities in the liquid 2 and to be able to keep the phase boundary, in particular the phase separating surface 16, at the height 15 of the distributor plates 23, 24, the lines 4 around the branching device 19 are used as flexible hose lines 2, that is to say that the three lines 4, 28, 29 which lead to and from the branch piece for the heavy phase 6 are formed at least in part from a flexible material.

It is also possible according to Fig. 3 that in the space between the distributor plates 23, 24, in particular close to the outer edge, a fine filter material 30, such as Wire, mineral or other fabrics or fibers are arranged. When the mixed liquid 2 flows through the filter material 30, a coalescence effect develops on the smallest droplets, which grow together at the points of intersection of the fibers of the filter material 30 to form larger drops and thus favor the separation. Due to the arrangement near the outer edge, the liquid flowing through is already widely distributed, as a result of which the speed is reduced and the pressure loss through the filter material 30 is thus kept very low.

In a further embodiment, which is not shown, however, it is possible that by arranging sensors for recognizing the phase separation surface 16 and electrical adjustment means for the branching device 19, the phase separation surface 16 is automatically adapted, in particular in the area of the distributor plates 23, 24, is possible so that the system can continue to operate autonomously even with continuously varying densities of the materials in the mixed liquid.

The gravity separation device 1 is preferably designed in such a way that standing phase separation containers 3, as shown, are more suitable for smaller flow rates. Lying round containers or cuboid tanks are more suitable for larger scales because of the larger horizontal cross-sectional area.

For the sake of order, it is pointed out that the invention is not limited to the illustrated embodiment variants, but may also include further training.

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Claims (19)

claims 1. A method for separating a mixed liquid (2), in which the liquid (2) is fed into a phase separation container (3) via a feed line (12), the mixed liquid (2) in the phase separation container (3) due to the force of gravity. is separated into a heavier phase (6) and a lighter phase (7) of the liquid (2), the heavy phase (6) of the liquid (2) in the lower region (13) and the light phase (7) in the upper region (14) of the phase separation container (3) is collected and the liquids (2) of the individual phases (6,7) are discharged via lines (4,5), characterized in that the introduction of the mixed liquid supplied is approximately at the height ( 15) of the phase separating surface (16) of the two phases (6, 7) of the liquid (2), preferably continuously at a low flow rate, the phase separating surface (16) being between a lighter phase (7) of the liquid (2) and a heavier phase (6) of the liquid (2), the mixed liquid (2) being introduced between two horizontal distributor plates (23, 24). 2. The method according to claim 1, characterized in that the heavy phase (6) of the liquid (2) at the lowest point, in particular a bottom outlet (18) of the phase separation container (3) is discharged via a first line (4), the From there, the line first rises with a branching device (19), which is arranged higher than the floor outlet (18), and is connected to the highest point (20) of the phase separation container (3). 3. The method according to claim 1 or 2, characterized in that the lighter phase (7) of the liquid (2) in the upper region (14) of the phase separation container (3) by a further, positionally above, but otherwise independently of the branching device (19 ) arranged overflow (21), such as an overflow funnel, is discharged via a further line (5). 4. The method according to one or more of the preceding claims 1 to 3, characterized in that by adjusting the height of the branching device (19), the height (26) of the overflow for the heavy phase (6) and consequently the height (15) of the phase separation surface (16) is set. 5. The method according to one or more of the preceding claims 1 to 4, characterized in that the phase separation surface (16) is set in the region between the upper and lower distributor plate (24, 25). 6. Gravity separation device (1) for separating a mixed liquid (2) and for carrying out the method according to one or more of the preceding claims 1 to 7, comprising at least one phase separation container (3), in particular a gravity separation container (3), a first line (4 ) for the heavier phase (6) of the liquid (2), a second line (5) for the lighter phase (7) of the liquid (2) and collecting container (8,9) for the separate phases (6,7) of the liquid (2), characterized in that a phase separating surface (16) is aligned or formed at the same height (15) of an inflow opening (17) for the mixed liquid (2), two horizontal distributor plates (23, 24) are arranged, between which an inflow opening (17) for introducing the mixed liquid (2) is arranged. 7. Gravity separating device according to claim 6, characterized in that the phase separation container (3) has a bottom outlet (18) at the lowest point, to which a line (4) for removing the heavy phase (6) of the liquid (2) is connected, wherein the line (4) is connected to a branching device (19) and a ventilation opening (22) at the highest point (20) of the phase separation container (3). 9.14 AT518 686 B1 2018-03-15 Austrian patent office 8. Gravity separation device according to claim 6 or 7, characterized in that in the phase separation container (3) for the light phase (7) of the liquid (2) an overflow (21) in the upper region (14) is arranged, which with a line (5 ) for discharging the light phase (7). 9. Gravity separating device according to one or more of the preceding claims 6 to 8, characterized in that in the phase separation container (3) in the height range where the position of the phase separation surface (16) is intended, two horizontal distributor plates (23, 24) are arranged and with the feeder line (12) are connected, between the outer edges of which a long, narrow inflow opening (17) for introducing the mixed liquid (2) is formed. 10. Gravity separating device according to one or more of the preceding claims 6 to 9, characterized in that the phase separating surface (16) at height (15) between the two horizontal distributor plates (23, 24) via the height of the branching device (19) and the balance between the liquid columns of the heavy phase (6) in the riser from the bottom outlet (18) to the branching device (19) on the one hand and the composite liquid column of heavy and overlying light phase (6,7) inside the phase separation container (3) to the top Overflow (21) on the other hand is aligned or adjustable. 11. Gravity separating device according to one or more of the preceding claims 6 to 10, characterized in that the separation phase surface (16) is adjustable in height (15) by adjusting the branching device (19). 12. Gravity separating device according to one or more of the preceding claims 6 to 11, characterized in that the line (4) for the heavy phase (6) and for ventilation above the branching device (19) / overflow is flexible. 13. Gravity separating device according to one or more of the preceding claims 6 to 12, characterized in that the lines (4,5) for the light and heavy phases (6,7) are each connected to a collecting container (8,9). 14. Gravity separation device according to one or more of the preceding claims 6 to 13, characterized in that the upper end of the line (4) for the heavy phase (6) with the free gas space in the uppermost region of the phase separation container not completely filled with liquid (2) (3) is connected. 15. Gravity separating device according to one or more of the preceding claims 6 to 14, characterized in that the three lines which lead to and from the branch piece for the heavy phase are formed at least in part from a flexible material. 16. Gravity separation container (3) for separating mixed liquids (2) and for use in a gravity separation device (1) and a method according to one or more of the preceding claims 1 to 16, comprising at least one inflow opening (17) for a mixed liquid (2 ), a bottom outlet (18) for a heavy phase (6) of the liquid (2) and a higher overflow (21) for a light phase (7) of the liquid (2), the bottom outlet (18) and the upper one Overflow (21) are connected to lines (4, 5), characterized in that two horizontal distributor plates (23, 24) are arranged in the lower region (13), between which a wide inflow opening 17 for introducing the mixed liquid is arranged or is formed, and that when the liquid 2 is filled in, a phase separation surface 16, which separates the light phase 7 from the heavy phase 6, in the area 25 between the two distributor plates 23,24 is adjustable or arranged. 17. Gravity separation container (3) according to claim 16, characterized in that the line (4) for the heavy phase (6) is connected to a branching device (19). 10/14 AT518 686 B1 2018-03-15 Austrian patent office 18. Gravity separation container (3) according to claim 16 or 17, characterized in that the separation phase surface (16) is adjustable by adjusting the branching device (19) in height (26). 19. Gravity separation container according to one or more of the preceding claims 16 to 18, characterized in that the phase separation container (3) has a sight glass, which is preferably arranged in the region of the distributor plates.