DE8909733U1 - Light liquid separator - Google Patents

Description

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T 759 Ma

Light liquid separator

The invention relates to a light liquid heater si", the features of the preamble of claim 1.

Such light liquid separators are available on the market. The requirements for such light liquid separators are summarized in the German DIN standard 1999 Part I. When manufactured from concrete, it is necessary, among other things, that "water-impermeable concrete" is used in the sense of the German DIN standard 1045, which must be provided with an oil-resistant and oil-tight protective coating over the entire area of the interior wall surfaces that can be exposed to light liquids, since water-impermeable concrete alone does not guarantee impermeability against chlorinated hydrocarbons.

Light liquid separators according to the invention are used in particular for surface drainage, preferably of car washes, in particular truck washes, parking lots, petrol stations and storage areas for light liquids. Light liquid separators according to the invention can also be used for waste water from industrial processes, provided that the functional requirements are met.

In the first-mentioned application area, e.g. the drainage of parking lots or car washes, wastewater mixed with light liquids must be processed in batches, e.g. after a downpour or in the case of current vehicle suction cleaning. This can also lead to a short-term back-up of wastewater in front of the light liquid separator if the absorption and permeability of the light liquid separator has slightly increased the amount of wastewater currently being discharged. In such cases, the

\ The level of the wastewater or the light liquid layer already separated at the top can reach significantly higher heights than the level of the inlet and outlet openings in the concrete of the tank shell, and this is based on the principle of communicating pipes between the inlet level of the wastewater and the level of the wastewater in the tank, apart from dynamic effects. The height range above the inlet and outlet openings therefore also functions as a liquid buffer for surge operations. The inner wall surface of this liquid buffer is therefore also contaminated by light liquid at least temporarily, possibly even for longer periods of time.

The purpose of light liquid separators is to protect the environment from contamination by light liquids and to separate and dispose of any light liquid contamination from the wastewater.

There is now a large number of light liquid

There are no separators on the market that meet this objective well at the time of their installation, either as a pure gravity separator or as a coalescence separator ** with the installation of materials which convert the light liquid fractions into a larger droplet form through interfacial interaction in order to improve the efficiency of the light liquid separation.

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However, the known light liquid separators have the disadvantage that their design does not provide an optimal guarantee against leakage into the surrounding area during continuous operation. This is particularly critical when the light liquid container is installed largely sunk, as is usual. In this case, rnsn can still detect or catch any leakage that may occur in the area of the upper cover or permanently exclude it through particularly careful manufacturing; however, leakage from the jacket area below the cover into the surrounding soil or other visually less accessible areas can remain undetected for a long time, so that the container can "dispose of itself" into the surrounding area, e.g. into adjacent soil. This then runs diametrically counter to the purpose of installing the light liquid separator.

A main source of such leakage into the surrounding area during continuous operation are structural joints in the tank body. Such joints can be caused in particular by a sectional structure made up of different elements of the tank body or by pipe penetrations, which are not desirable in themselves according to DIN 1999 due to their potentially harmful effects. Material pairings at such an interface made of different materials with different thermal expansion coefficients are particularly critical.

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It is true that permanent sealing can be achieved in the area of such interfaces using sufficiently complex methods. However, this increases the manufacturing costs of such a light liquid container to an unacceptable extent and moreover, sometimes there is no guarantee against systematic leaks or botched workmanship.

Examples of known light liquid separators, whose durability is doubtful due to leakage of light liquid into the outside area, are given below:

In the light liquid separator according to AT-PS 386 402 B, the container is indeed constructed in one piece from its base to a cover joint at the upper end of a cover lid. However, both the inlet and outlet openings in the container shell are arranged above the lower limit of the separated light liquid column, so that if the pipe ducts leak through the container wall, the aforementioned "self-disposal ^11" can occur in the area surrounding the container wall. Furthermore, characteristically, in EU-B1 00 46 271, the light liquid separator 2 in Fig. 1 is arranged in a corresponding position of the inlet and outlet of the waste water containing light liquid, although a filter device 1 arranged downstream in terms of flow is only provided with connections in the base area of the filter container.

Similar criticism should also be made of light liquid separators in which one of the inlet and outlet openings is located below the area that can be contaminated by light liquid,

the other, however, is arranged above the lower limit of the light liquid column. An example of this is the light liquid separator according to DE-U 1 85 15 036.3. In this known light liquid separator, a single container is divided into two separation chambers. The communication between the two chambers takes place below the area of the inner wall surface of the BphSltprnianhplß that can be contaminated by the light liquid. &ohgr; Jähr &bgr;&eegr; rl -iodnnh the Ztil on in the - .- — __ _r .. _.—— _ j _ — · - - _

first chamber and the outlet from the second chamber are arranged above the lower limit of the light liquid column.

It was already known from DE-U 1 85 35 037.0 (Fig. 1) to arrange the inlet and outlet openings in the base area of a cast-iron lower part of a light liquid separator, but on the other hand to supplement the container at the top with a concrete container ring. The connecting joint between the cast iron of the lower part and the concrete of the upper part is thereby highly endangered in the sense of the aforementioned "self-disposal" into the surrounding area. Insofar as light liquid separators with a concrete container are addressed in the same DE-U 1 85 35 037.0 (Fig. 2), at least one opening is provided in the upper container area that can be contaminated by light liquid, unlike the cast-iron lower part of the first-mentioned design. This is probably due to the fact that molds with destructible cores are used for iron casting, whereas reusable molds are used for concrete molding. Models from iron casting and comparable techniques cannot therefore simply be transferred to the production of concrete containers.

The invention is therefore based on the object of creating a light liquid container in concrete technology of the type mentioned in the preamble of claim 1,

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which, in a simple, cost-saving design, avoids as reliably as possible the aforementioned "self-disposal" of light liquid from the light liquid container into the surrounding area of the container shell and at the same time provides a cost-effective design for other designs and further developments of light liquid containers.

This task is performed by a light liquid

i>et>.ältcr ITilt. ucm features u«=5 ObeifbcyXif f 5 Vöii AfisprüCu 1 carch the characterizing features of claim 1 are solved.

By arranging the openings of both openings below the specified lower limit of the light liquid column, it is ensured that in the area of the opening only water, but not light liquid, can escape into the surrounding area. On the other hand, the inner wall surface, where it can be exposed to light liquid in the area of the light liquid column to be separated as intended and above it in overload operation, is kept completely free of openings and gaps that could cause leaks. It is taken into account that according to SIN 13SS the storage space that can be exposed to light liquid even in the event of overload should end at the top at a maximum of 40° below the cover or the joint between the container and the cover and therefore, if the light liquid separator is installed correctly, the joint between the container and the cover cannot be exposed to light liquid.

All of the above aspects can be achieved with an extremely simple design of the light liquid separator, which can thus be manufactured in large quantities at low cost with the highest level of long-term operational reliability. The interior wall coating can be easily inspected and, if necessary or renewed on a regular basis, thanks to the simple design of the storage space during regular disposal of collected light liquid from the light liquid storage.

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It is usual and sensible to arrange the inlet opening and the outlet opening of the light liquid separator - or its external pipe connections - in an upper area of the light liquid container. In this case, a pipe system arranged completely outside the container to the inlet and outlet openings can be provided . However, these openings or pipe connections are preferably formed on the container shell itself according to claim 2. In this case, pipes can be laid inside the container shell if necessary. According to claim 3, however, the corresponding pipes or channels can also be formed directly in the concrete of the container shell and provided with an oil-resistant and oil-tight protective coating at least on the inlet side.

This protective coating, or a coating with the same effect, must be applied at least where light liquids can get into connecting channels and in the interior of the light liquid separator during operation. However, all interior wall surfaces and channel surfaces exposed to waste water can also be painted accordingly &psgr;

or coat. I

Claims 4 to 7 deal with a further development of the inlet-side connection between the inlet opening and the mouth of the inlet-side opening in such a way that the waste water enters the container in a flow that promotes separation and is distributed over it in such a way that the entire cross-sectional volume between the inlet and outlet of the waste water can be used as a separation volume. Grid installations in the inlet that are known per se and are known for a corresponding flow-calmed waste water discharge (see, for example, the aforementioned DE-U 1 85 3b 037.0) are also possible, but are usually even dispensable. The measures of the

Claims 4 to 7 if they are implemented directly by appropriate shaping of the concrete according to claim 2. In this case, you can completely dispense with fittings for this purpose and thus keep the structure of the light liquid separator extremely simple while maintaining full functionality. In some cases, you can even avoid filling the inner cross-section of the container with fittings intended to calm the flow.

My «target direction, namely an internal

rauai weitiBSgllchst; &zgr;&lgr;&igr;&zgr; lÄlcbfcflÜssiglsiaitiSäbscheiäurig to be provided and required fittings either omitted or In order to arrange the float valve arrangement in the container with the lowest possible cross-sectional consumption, the float valve arrangement according to claim 8 is designed on the outlet side of the container.

It can be useful, regardless of the cross-sectional dimensions of the inlet and outlet of the waste water, to further restrict the flow through the light water separator between the inlet and outlet openings and to choose the restriction so that the central container space between the inlet and outlet openings is also as evenly flowed through by the waste water as possible, thus creating a maximum separation effect in the separator. A corresponding measure is provided for in claim 9. The arrangement of such a perforated partition wall is known per se in a foam separation device according to DE-OS 31 43 548 AI, but there in conjunction with an additional perforated partition wall in the inlet area of the container. Within the scope of the invention, such an additional perforated partition wall in the inlet area is usually unnecessary; on the contrary, two or more partition walls are more likely to be provided in the central area or, as mentioned, such a partition wall can be dispensed with entirely.

The light liquid separator according to the invention can be a pure gravity separator. Gravity separation already occurs when the wastewater containing light liquid is passed under a baffle.

Such a baffle already represents the inlet-side container inner wall with a connection according to claims 2 to 7 between the inlet opening and the inlet-side opening. With such a gravity separator, the implementation of claim 9 is expedient, e.g. for gasoline separators or other light liquid separators where, for example, a 97 percent separation is sufficient.

Preferably, however, according to claim 10, at least one installation containing coalescing material is present in the light liquid separator, whereby the light liquid separation is promoted above the area = gravity separation caused by the different specific weight, for example to about 99.9% separation. It is known to subdivide such an installation containing coalescing material (cf. e.g. the already mentioned AT-PS 386 402 VI) into several chambers arranged vertically one above the other in order to reduce the flow resistance through the coalescing material (cf. DE-PS 16 45 762). Such a measure is also preferred within the scope of the invention.

Claims 12 and 13 strive to further optimize the efficiency of the separation by means of coalescing material, namely claim 12 with the most optimal use of the entire container height and claim 13 with the most optimal use of the container cross-section while minimizing the installation effort required by the level control of the separated light liquid column by means of the generic float-controlled valve device.

According to claim 14, the

The container cross-section that can be achieved with the required material is further optimized in accordance with the task, with claim 15 specifying a particularly simple design when implemented in accordance with claims 2 to 7.

' From EU-A1 00 17 649 it is known (positions 20 and 21), a light liquid container through a surrounding base in the container

Jj foot area to protect against the fact that if he only partially

filled with water, with rising groundwater levels

:| floats. In this case, a rising upwards

% expanding cone of soil on the projecting surrounding base.

In the well-known light liquid separator,

vj this base preventing floating is made of a different material and _cast onto the actual separator container, which is made of a flat material. f Claim 16 provides for such a base preventing floating when the groundwater level rises to be formed in the concrete of the light liquid separator according to the invention. Claim 17 provides for an outer contour adapted to the transport dimensions of the light liquid container on public roads, with claim 18 again aiming at minimizing the material and also minimizing the transport length.

' For the items marked "in particular"

Independent protection is expressly sought for these claims. In particular, the characterizing features of these subclaims are to be read as referring to the generic term of claim 1.

The invention is explained in more detail below using schematic drawings of two exemplary embodiments. They show:

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Fig. 1 a vertical section running diametrically through the inlet and outlet of the waste water and

Fig. 2 a plan view of a first embodiment of a light liquid separator as a gravity separator and

in a corresponding representation as in Fig. 1 and 2

in Fig. 3 and 4 a vertical section and a top view of a second embodiment of a light liquid separator, the illustration of which in

Fig. 5 is supplemented by a further vertical section along the line A-B in Fig. 4.

Both embodiments of a light liquid separator show an upright container 2 with a container base 4 and a container shell 6, which is made in one piece from waterproof reinforced concrete and is provided with an oil-resistant and oil-tight protective coating (not shown) or a corresponding coating on all inner surfaces exposed to waste water _: As shown in detail in the plan views of Fig. 2 and 4, the container shell 6 is cylindrical with a constant wall thickness except for the inlet and outlet areas of the waste water, the inlet and outlet areas of the waste water being arranged within diametrically opposed areas of the container shell 6, where the container shell 6 is formed with external bulges 8 and 10 with increased wall thickness.

On the top of the cylindrical area of the container shell 6 lies a cover 12 which, like the container 2, is made of water-impermeable reinforced concrete and is covered with oil-resistant and oil-tight

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Protective paint or a corresponding coating and forms a horizontal circular disk. In the support area of the lid 12 on the container 2, a circumferential seal 14 is provided, which should be as permanently watertight as possible and impermeable to light liquids, for which purpose, for example, an appropriate sealing mortar can be used. The lid 12 has a preferably central, but possibly also a differently arranged manhole 16, through which the maintenance and disposal of light liquids from the container 2 can take place. A shaft ring 18 is placed on the lid 12 in an axial extension of the manhole 16 upwards, which typically has a height of between about one and three meters. A perforated disk 20 is placed on top of the shaft ring 18, the hole of which can be closed by an insertable closure lid 22. At least the shaft ring 18 and the perforated disk 20 are made of the same type of concrete as the container 2 and the lid 12, are provided with an oil-resistant and oil-tight protective coating or a corresponding coating on the inside and are sealed against each other in the same way as described in the case of the seal 14 between the container 2 and the lid 12. The closure lid 22 can be made of cast metal in the conventional way and must be sealed against the perforated disk 20 in accordance with the regulations with the same sealing requirements. In the case of all seals, sealing against light liquid vapors must also be ensured.

The hole in the perforated disc 20 should also have a manhole-sized cross-section. When installed, especially when installed in the ground, it must be ensured that at least the area of the hole in the perforated disc 20 that can be releasably closed by the cover 22 is located above the highest waste water inlet. It is better if the highest waste water inlet is not located higher than 40 mm below the upper face 42 of the container casing 6.

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In the foot area of the container 2 or on its container bottom 4, an outer bead 26 running horizontally along the outer wall surface 24 of the container 2 is formed in the concrete of the container and serves to support the container 2 against floating up under groundwater buoyancy when installed in the ground. As can be seen in the sectional view of Fig. 5 and is also implemented in the first embodiment, but not shown, the outer bead 26 has a vertical outer contour 28 which merges into the lower area of the outer wall surface of the container shell 6 via an inclined surface 30 rising from radially outside to radially inside. The outer contour 28 has almost the same height as the thickness of the container bottom. The inclined surface 30 is inclined at an acute angle to the horizontal. The outer contour initially describes two parallel straight lines 32, the distance between which corresponds to the smallest outer width of the container, i.e. the outer diameter of the cylindrical part of the container shell 6, and which touch the cylindrical outer wall surface 24 of the container 2 at right angles to this smallest outer width in the area of the tangential inlet points 34, so that the outer bead is recessed there. The outer bead 26 is also recessed in the area of the bulges 8 and 10, so that the outer bead as a whole runs like a fin between the bulges 8 and 10 and the tangential inlet points 34 over only a partial quadrant of the container circumference. The ends of the straight lines 32 are selected so that outside the straight lines 32 the outer contour 28 of the outer bead 26 runs at least approximately parallel to the cylindrical outer wall surface 24.

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In the area of the inlet-side bulge 8

' within the concrete of the container shell 6, an inlet-side opening 36 is formed through which waste water possibly contaminated with light liquid can enter the interior of the container 2. Accordingly, in the area of the outlet-side bulge 10 in the concrete of the container shell 6, an outlet-side opening 38 is formed through which the waste water can flow out again to the outside after the light liquid contaminants have largely been separated from the interior of the container.

The inlet-side opening 36 leads from an inlet opening 40, which is arranged in the upper region of the outer wall surface 24 of the container shell 6 - preferably just below its upper end face 42 - to a mouth 44 of the inlet-side opening 36 into the interior of the container 2. The inlet opening 40 can be designed in a manner not shown as a connecting piece or connecting sleeve for an inlet pipe. From the inlet opening 40, the inlet-side opening 36 runs as a channel 46 formed in the concrete of the container shell 4 to the mouth 44, without any built-in components other than a protective paint or coating for the purpose of oil resistance and oil-tightness. The channel 46 has a round cross-section adjacent to the inlet opening 40, which initially extends over an area 48 curved by 90°. into a vertical connecting channel 50 and ends in a still circular outlet cross-section 52.

The outlet cross-section 52 is connected to the mouth 44 in the interior of the container 2 via a transition area

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54, which is designed as a funnel-shaped extension from the outside to the inside. In this case, the outer wall of the inlet-side bulge 8 initially jumps back inwards from the outlet cross-section 52 and from there forms a wall area 56 of reduced wall thickness from the recess 58 at the level of the outlet cross-section 52. The recess is, for example, dimensioned at around 40 mm in the radial direction. The boundary wall 60 facing the interior of the container 2, which also radially limits the outlet cross-section 52 with its lower end, has a lower end face 62 which, for technical reasons, is located somewhat higher than the recess 58. Nevertheless, the connecting channel 50 opens vertically above the outlet cross-section 52 into the funnel-shaped extension of the transition area. Due to the recess 58, the outlet cross-section 52 functions like a free pipe that opens vertically into a free volume, here the transition area 54, as far as the flow conditions of the pumped wastewater are concerned.

The wall area 56 of reduced wall thickness merges at the bottom into a flow-deflecting outer flank 64 of the funnel-shaped extension formed by the transition area 54, which is opposite the outlet cross-section 52 and expediently takes up at least its cross-sectional area and is shaped here as a straight inclined surface. In a manner not shown, a continuously curved transition can alternatively be provided in the area of the flow-deflecting outer flank. This runs below the boundary wall 60, preferably as shown in alignment with its outer wall surface located furthest radially inward, into the horizontal upper side of the container base 4. As a result, the

Mouth 44 between this upper side 66 of the container bottom and the lower end face 62 of the boundary wall 60 is limited in the vertical direction.

The elements of the funnel-shaped transition in the vertical direction are described in detail. In the horizontal direction, a funnel-shaped transition into the circular inner cross section of the interior of the container 2 is also made by a funnel-shaped extension 70 formed on the inner wall surface of the container shell 6 (see also Fig. 2 and 4), which at the transition area 54 leads in the horizontal direction initially with a slight curvature and then essentially straight up to approximately a mouth 72 located at a quarter of the inner diameter of the container 2 and introduced approximately tangentially into the normal cylindrical inner cross section of the container shell 6.

In the outflow-side bulge 10, which is diametrically opposite the inflow-side bulge 8, a vertical connecting channel 74 is formed in the concrete of the container shell 6, which, as shown in Figs. 2 and 4, has a trapezoidal clear cross-section with a larger base area lying radially inward and is therefore complementary to the rounded trapezoidal shape of the two bulges 8 and 10. With a slight downward offset 78 compared to the upper edge of the inflow opening 40, a round outflow opening 80 with a horizontal axis and the same right cross-section opens into the connecting channel 74. As a result, the lower edges of the inflow opening 40 and outflow opening 80 are also slightly offset from one another. The offset of the outflow opening compared to the inflow opening 40 is dimensioned such that a gradient flow generated solely by gravity from the inflow opening through the internal volume of the container 2

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40 to the drain opening 80.

The lower end of the connecting channel 74 opens out into a deflection slope 82, which can also be curved, and the outer wall surface of the connecting channel 74 is transferred to the top of the container body 4. In this case, between the inner wall 84 of the connecting channel 74 and the surface 66 of the container body 4, a drainage channel 74 is formed into the inner volume of the container 2, through which drainage channel can flow out of the said inner volume of the container via the drainage channel or the drainage opening 80. The entire opening 74 from the outlet 86, the connection channel 74 and, if necessary, the drain opening 40 can in turn be formed completely in the concrete of the container shell 6, whereby the drain opening 80 can in turn be formed with a pipe connection piece or a pipe connection sleeve. These connection means can also be formed in the concrete. However, appropriate connection means can also be used in a sealed manner. It is not absolutely necessary, but also possible, to provide the opening 38 with an oil-resistant and oil-tight protective coating or an appropriate coating.

A pipe bend 88 is tightly inserted into the mouth 86. To facilitate insertion, the outlet of the deflection slope 82 into the upper side 66 of the container base 4 is offset slightly radially outwards compared to the most radially inner flank of the vertically running connecting channel 74 in order to enable a good insertion depth of the pipe bend 88.

The pipe bend 88 extends into the cylindrical inner volume of the container 2 and carries, slightly offset from the cylindrical inner wall surface of the container shell 2

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a valve seat 90 which is arranged horizontally and interacts with a* valve plate 92 which can be moved up and down.

The valve disk 92 is firmly connected to a vertically upwardly projecting actuating shaft 94, which is firmly connected at its upper end to a float 96. The float is designed to be clearer than water, but heavier than the light liquid to be separated, so that it always floats on the interface 98 between the waste water and the separated light liquid column 100 layered above it. The length % of the actuating shaft 94, which serves as the actuating element for the

The shut-off disc valve fi formed by valve seat 90 and valve disk 92 is dimensioned such that the shut-off valve closes when a predetermined lower limit 98 of the light liquid column 100 I separated in the inner volume of the container 2 is reached.

The assembly comprising the float 96, the actuating shaft 94, which may be adjustable in length, and the valve plate 92 is guided vertically in a known manner by a cage 102 with vertical guide rods 104, this cage 102 being attached to the inner wall surface of the container casing 6.

It can be seen that the pipe bend 88 is also designed with a flow-diverting slope 107 at the bottom adjacent to the valve seat 90, which can, however, be replaced by a normal curved course of a pipe bend.

As is clear from the top views of Figs. 2 and 4, the pipe bend 88, valve seat 90, valve plate ⁹² and, appropriately, the cage 102 together with the float 96 have elongated, preferably rectangular, rounded corners.

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Cross section with the longitudinal axis extending along the inner wall surface of the container shell 6 in order to connect a large drain cross section with as little as possible filling of the horizontal inner cross section of the cylindrical container 2. In addition, wall fittings can be moved as close as possible to the drain in the transverse direction to the connecting plane of the inlet and outlet. This is realized in the special case of the second embodiment according to the following description.

As soon as the container 2 is filled with waste water, an uppermost liquid level 106 forms in stationary operation at the level of the lower edge of the drain opening 80. This liquid level 106 then simultaneously represents the level of the light liquid column 100 separated above the water portion of the waste water.

In the dynamic case of an excess supply of waste water, however, the level 106 can rise upwards and, in special cases, even above the upper edge of the inlet opening 40, so that practically the entire cylindrical internal volume 2 not occupied by fittings above the level 98 and, if properly installed, below an upper limit of 40 mm below the joint 110 of the container shell 6 with the lid 12 forms a storage space 108 for liquid.

In both embodiments of light liquid separators, the mouth 44 of the inlet-side opening 36 and the mouth 86 of the outlet-side opening 38 are always arranged below the specified lower limit of the light liquid column 100 separated in the inner volume of the container 2 due to the level control by means of the disk valve arrangement, in such a way that there is no danger of light liquid from the light

liquid column 100 can leak radially outwards through gaps in the container wall 6. By ensuring sufficient vertical distance between the upper edges of the openings 44 and 86 from the lower limit 98, even leakage from not yet completely separated wastewater portions below the lower limit 98 is prevented. This leakage protection against radial leakage flow through gaps is not only provided up to the upper liquid level 106, but in practice even up to the cover joint 110 located at the upper end of the container 2, where the seal 14 prevents leakage. In principle, it would be sufficient if the jointless flow ended only 40 mm below the joint 115 if installed correctly, a restriction that is usually unnecessary if additional leakage protection is provided.

Accordingly, the container shell 6 is kept completely free of openings and joints leading to the outer wall surface 24 of the container shell 6 from the upper edge of the mouths 44 and 86 up to the cover joint 110. In particular, this area of the container shell 6 kept free of openings and joints already begins below the specified limit 98.

The entire above description refers to both embodiments of Fig. 1 and 2 on the one hand and 3 to 5 on the other hand. The embodiments differ in the following:

The first embodiment of Fig. 1 and 2 is a pure gravity separator without any internals with coalescing material.

In this case, the wall area of reduced wall thickness 56 has a relatively large vertical extension such that the mouth 44 with its funnel-shaped transition also has a very large, uniform entry cross-section into the storage chamber 108 for the waste water. The

4*

Distance between the front surface 62 of the boundary wall 60 and the top side 66 of the container base 4 should be approximately the same height as the distance between the front surface 62 and the lower edge of the inlet opening 40. In practice, the first-mentioned distance will be slightly smaller than the second-mentioned distance.

The storage space iuo is also kept completely or at least largely free of any built-in components other than the level control by means of the disk valve 90, 92. However, it is expedient to have (at least) one partition wall 112 perforated for flow distribution, which in the central area of the internal volume of the container 2 occupies the flow cross-section between the two mouths 44 and 86 of the openings 36 and 38. In the first exemplary embodiment, this partition wall 112 is arranged completely centrally; however, it can also be offset slightly in the direction of the inlet or the outlet without being expediently provided in the vicinity of the inlet and outlet. It is also possible to provide several partition walls in the central area in a form not shown, for example equidistant on both sides of the central position of the single central partition wall 112 provided in the first exemplary embodiment.

In the second embodiment, an installation 114 containing coalescing material is arranged in the storage volume, which here replaces the perforated partition wall 112, itself has a flow-distributing effect and, just like the partition wall "%2 of the first embodiment, in the second embodiment occupies the flow cross-section between the two mouths 44 and 86 of the openings 36 and 38.

However, it is not excluded to also provide for "oil" designs that combine at least one perforated partition wall and an installation containing coalescing material. However, this is not usually necessary.

Without loss of generality, the embodiment example of coalescing material 116 is described,

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Alwater floats up.

In the second embodiment, the installation 114 preferably has several, specifically three, chambers 118 arranged one above the other, each containing a layer of loosely floating coalescing material. This is enclosed at the top and bottom by sieve plates or similar structures so that the waste water, although not the coalescing material, can pass through. These sieve plates, grid structures or the like are expediently held by expandable frames which, in the pushed-together position, can be pushed vertically in through open cross-sections of U-shaped holding frames which are open to the inside and then pushed out to be inserted into the frames. The holding frames 122 of the perforated plates or the like 120 are attached to the inner wall surface of the container casing 6 with the crossbar of their U-profiles. The chambers 118 are delimited on the inlet side by the inner wall surface of the container shell 6 and on the outlet side by a liquid-tight partition wall 124 extending from the container bottom 4 to just below the specified lower limit 98.

This partition wall 124 is arranged in the manner already discussed above, parallel to the long side of the rectangular cross-section of the pipe bend 88, valve seat 90, valve plate 92, float 96 and cage 102 in its immediate vicinity. The partition wall can be subsequently attached to the container base 4; however, an integral design with the entire container 2 is preferred.

In the second embodiment, the height of the boundary wall 60 of reduced wall thickness in the transition area 54 on the inlet side is selected to be relatively short and thus also the height of the inlet-side opening 44 into the storage volume 108. This is justifiable because on the inlet side the waste water is distributed over the entire lower cross-section of the container below the lowest screen plate or perforated plate 120 or the like up to the partition wall 124 and then rises vertically with a calm flow. Here, the vertical flow takes a significant part in the flow through the interior volume of the container 2, separating light liquids, while in the first embodiment the flow essentially takes place across the container between the inlet and the outlet.

Claims (1)

Protection claims 1. Light liquid separator with - an upright container (2) made of water-impermeable concrete, in particular reinforced concrete, with an oil-resistant and oil-tight protective coating, which has a lid (12) provided with a maintenance opening (16) and tightly connected to the container, - inlet-side and outlet-side openings (36,38) in the concrete of the container shell (6), which open at opposite areas of the same from the outer wall surface (24) of the container shell into the inner volume of the container (2), - a float (96) designed to be lighter than water and heavier than light liquid, which controls a shut-off valve (90, 92) for the discharge via an actuating member (94), the length of the actuating member (94) being dimensioned such that the shut-off valve closes when a specified lower limit (98) of the light liquid column (100) separated in the interior volume of the container is reached, and - a storage space (108) for separated Light liquid, which is above the specified limit (98) of the light liquid column (100) laterally from the Inner wall surface of the concrete of the vessel shell (6) formed characterized , that the container (2) is raised to a level at the upper Encuä Cover joint (110) is formed in one piece, that the openings (44,86) of both openings (36,38) in the concrete of the inner wall surface of the vessel shell (6) are arranged below the specified upper limit (98) of the light liquid column ( ' Oü) uiss that the concrete of the inner wall surface of the container shell (ß) above a container level (stem surface 62) which is below the specified lower limit {M;} of the light liquid column (100) or at most equal to it, is kept completely free of openings and holes leading to the outer wall surface (24) of the container shell (6). 2 Liquid separator according to claim 1, in which an inlet opening (40) and an outlet opening (80) offset slightly downwards relative to the inlet opening to the extent that a gradient flow through the inner volume of the container is generated are arranged in the upper region of the outer wall surface (24) of the ketone tank (6), characterized in that both connections, on the one hand between the inlet opening (4C) and the mouth (44) of the inlet-side opening (36) into the interior of the container and, on the other hand, the mouth (86) of the outlet-side opening (38) from the interior of the container and the outlet opening (80) are designed as channels (46,74) running within the concrete of the container shell (6). [J 3. Light liquid separator according to claim 2, characterized ⁱⁿ that the connections are designed as channels (46,74) formed in the concrete. 4. Light liquid scraper according to claim 2 or 3, characterized in that on the inlet side the transition region ( 54) from the connection into the mouth (44) of the opening (36) as a funnel-shaped extension from the outside to the inside is trained. 5. Light liquid separator according to claim 4, characterized in that the extension extends practically continuously into the ·■ horizontal internal cross-section of the internal volume of the container (2) passes. 6. Light liquid separator according to claim 4 or 5, characterized in that the connection opens vertically into the funnel-shaped extension (outlet cross-section 52). 7. Light liquid separator according to claim 6, characterized by a flow-deflecting outer edge (64) of the funnel-shaped extension. 8. Light liquid separator in particular according to one of claims 1 to 7, in which the shut-off valve is designed as a disk valve, the disk (92) of which is connected to the actuating member (94) and the valve seat (90) is arranged on the top of a pipe bend (88), the other end of which is connected to the mouth (86) of the outlet-side opening (38), characterized in that the bend (88), valve seat (90) and disk (92) are elongated, • preferably have a rectangular cross-section, rounded at the corners, with the longitudinal axis extending along the inner wall surface of the container shell (6). -A- 9. Light liquid separator according to one of claims to 8, characterized by at least one intermediate wall (112) perforated for flow distribution, which in the central region of the internal volume of the container (2) occupies the flow cross-section between the two mouths (44, 86) of the openings (36, 38). 10. Light liquid separator according to one of claims to 9, characterized by at least one installation (114) containing coalescing material, which occupies the flow cross-section between the two mouths (44,86) of the openings (36,38). 11. Light liquid separator according to claim 10, characterized in that the installation (114) forms at least one chamber through which the flow flows from bottom to top, preferably several chambers (118) arranged vertically one above the other, which contain(s) the coalescing material (116). 12. Light liquid separator according to claim 11, characterized in that the chamber(s) (118) is (are) delimited on the inlet side by the inner wall surface of the container shell (6) and on the outlet side by a partition wall (124) extending from the bottom (4) of the container (2) to just below the specified lower limit (98) of the liquid column. 13. Light liquid separator according to claim 12, characterized in that the chamber(s) (118) takes up the entire horizontal cross-section of the internal volume of the container (2) with the exception of a residual cross-section on the outlet side in which the float (96), actuating member (94) and shut-off valve (90, 92) and optionally the elbow (88) are arranged. —5— 14. Light liquid separator according to one of claims 1 to 13, characterized in that the horizontal outline of the inner volume of the container (2) is circular. 15. Light liquid separator at least according to claims 2 and 14, characterized in that the outer contour of the container shell forms a circle concentric with the inner contour with the exception of the two opposite areas where the connections between the inlet and outlet openings (40, 80) and the associated mouths (44, 86) of the openings (36, 38) run within outer bulges (8, 10) of the container shell (6). 16. Light liquid separator in particular according to one of claims 1 to 15, characterized in that in the foot region of the container (2) an external bead (26) extending horizontally along its external wall surface (24) is formed in the concrete of the container (2) to provide support against floating under groundwater buoyancy when installed in the ground. 17. Light liquid separator according to claim 16, characterized in that the outer contour (28) of the outer bead (26) describes two parallel straight lines, the distance between which corresponds to the smallest outer width of the container and which touch the outer wall surface of the container shell at right angles to this smallest outer width in the area of which (inlet points 34). 18. Light liquid separator according to claims 15 and 16 or 17, characterized in that the outer bead (26) is recessed in the region of the bulges (8, 10).