Process for cleaning water and other liquids on the basis of the hydrodynamic effect

Abstract

The invention relates to a round container (1) for treating liquids, preferably for treating water. The round container (1) has a tangentially running inlet (2) at a central height, a tangentially running overflow (3) at the upper end of the round container (1), and a drain (4), which is designed as a dirt discharge (4), at the base in the center of the round container (1). The invention also relates to an arrangement of a plurality of round containers (1) connected one behind the other, to a water circuit system comprising at least one round container (1), and to a method for treating liquids, preferably for treating water.

Description

[0001] Purification of water and other liquids based on hydrodynamic effect

[0002] The invention relates to a circular container for liquid treatment, in particular for water treatment. The invention also relates to an arrangement of several circular containers connected in series. Furthermore, the invention relates to a liquid circulation system, in particular a water circulation system, with at least one circular container. Furthermore, the invention relates to a method for liquid treatment, in particular water treatment.

[0003] Many processes generate contaminated fluids used for the respective process, which must be subjected to a cleaning process before being reused. Water contaminated with dirt particles, especially wash water, wastewater, or process water, is generated in many different processes and should be cleaned before being returned to a water cycle. This applies to almost all cleaning processes for any object. A typical example of a cleaning system that performs such processes is a car wash.

[0004] Manual or mechanical exterior cleaning of a motor vehicle is performed using wash water, which loosens the dirt present on the vehicle's surface, cleans the vehicle's surface, and carries the dirt away. Since the surface of the vehicle may contain environmentally harmful substances such as lubricating oil residues, fuel residues, soot, or other potentially harmful contaminants, the wash water itself, contaminated with dirt, must be treated before being discharged into the sewer system.

[0005] Car washes often have so-called tunnel car washes and also gantry car washes. While in gantry car washes, the vehicle is stationary and is usually cleaned by the user, in tunnel car washes, cleaning is automated across several stations, with the vehicle being moved from one station to the next.

[0006] Furthermore, cleaning agents must be used in car washes, and especially in automated car washes, to enable or support various processes in the cleaning of the vehicle. For example, a highly alkaline chemical pre-cleaner is used in the first process to remove stubborn dirt, such as insects and bird droppings, from the vehicle body. In contrast to the cleaning agents used in later processes, the pre-cleaner is highly alkaline, i.e., has a high pH value, and enters the washing cycle. In contrast, the brush shampoo used in a subsequent mechanical cleaning process is acidic, i.e., has a lower pH value. Typically, contaminants, oil residues, and the like are separated or filtered out of the wash water using flocculation chemicals or sand or gravel filters before it is reused or discharged into the sewer system.

[0007] In order to reduce water consumption and thus minimize environmental pollution, car wash systems are already in operation in which the wash water is at least partially recycled. For recycling, the resulting wastewater is first fed into a sufficiently sized settling tank. The settling tank acts as a sludge trap, separating any suspended solids carried in the wastewater. The wastewater is then passed through one or two biological stages before being purified and reused as wash water for cleaning vehicles. Biological water treatment is achieved through natural processes with the help of microorganisms. Care must be taken to ensure that a pH value favorable for the survival and reproduction of the microorganisms is maintained during the biological treatment stages.Furthermore, in the final stage, a post-clarification takes place in which abraded biofilm is separated.

[0008] However, the contaminants separated in the individual stages must be removed from the tanks in the treatment stages from time to time, whereby the treated water should not be contaminated again if possible. During operation, the sludge level in the individual tanks rises, so that the water volume in the tanks decreases and sludge can be carried along by the water flow when the flow is stronger. As a result, conventional recirculation systems result in a permanent increase in contaminants in the system without any self-cleaning ability to take place during operation. Furthermore, a higher throughput in conventional systems usually leads to a higher flow velocity and lower sedimentation, which impairs water quality. Large amounts of chemical flocculants are also often used to reduce turbidity caused by inefficient treatment.However, the use of flocculants leads to an increased sludge volume. Furthermore, the chemicals used for flocculation are not biodegradable. The inlet and overflow of a cleaning tank or container are usually at the same level or on the same plane, allowing for bypass flow between the inlet and overflow. Due to the deteriorating water quality of the recycled wastewater, a large amount of fresh water in the form of drinking water must usually be fed into the cycle. To keep the total amount of wash water constant, a large amount of excess water must be constantly drained away, which further increases water consumption. During water shortages in summer, particularly in areas with little rainfall, the high water consumption can even lead to the washing operation being suspended.

[0009] The use of appropriately dimensioned centrifugal separators for pre-cleaning is also very energy-intensive.

[0010] It is therefore an object of the present invention to enable a more efficient, more flexible and more robust purification of water, in particular in a largely closed circuit, particularly preferably of a motor vehicle cleaning system.

[0011] This object is achieved by a round container for liquid treatment, preferably for water treatment, according to claim 1, a container arrangement with a plurality of series-connected round containers according to claim 7, a liquid circulation system, preferably a water circulation system with at least one container arrangement according to claim 8 and a method for liquid treatment, preferably for water treatment, according to claim 12.

[0012] The circular container according to the invention for liquid treatment, preferably for water treatment, in particular for wash water treatment or waste water treatment, has a tangentially running inlet at medium height, a tangentially running overflow at the upper end of the circular container and an outlet, which is designed as a dirt discharge, at the bottom in the center of the circular container.

[0013] When water is referred to as a cleaning medium, other liquids that can be used for cleaning are also included below.

[0014] In this context, a round container is understood to be a container that has the shape of a vertical hollow cylinder with a base surface at one axial end of the hollow cylinder. The walls of the hollow cylinder are preferably oriented perpendicular to the base surface. The base surface forms a surface with a smooth border or circumference. "Smooth" is understood to mean a differentiable circumference. The base surface preferably has the shape of a circle, but can also be slightly conical or concave.

[0015] “Tangential” is understood to mean an arrangement that is essentially tangential to the round container. “Essentially” here means that the usual tolerances and deviations in the design of such an arrangement are taken into account. The decisive factor is that the flow direction of the inlet and outlet enable a smooth circular flow in the round container, which is required for the cleaning function of the round container and the water. The upper end of the round container is considered to be the end of the round container axially opposite the bottom or underside of the round container, which can be open or closed at the top. The “center” of the round container according to the invention is understood to be a central longitudinal axis of the round container, which is characterized as the center of a circular flow in the round container, i.e. a center around which the water rotates as it flows through the round container.The center at the bottom of the round container is to be understood as a point where the central longitudinal axis passes through the bottom, preferably a geometric center of gravity, in particular a center point of the base area of ​​the round container.

[0016] Washing water is understood to mean water that is used to clean objects or persons, in particular motor vehicles or the like.

[0017] In this context, wastewater is understood to mean water, preferably process water or industrial water, in particular drinking water, whose properties have been altered through commercial use. These properties generally change in such a way that the possibilities for further use of the water are restricted or the requirements for disposal of the previously used water increase due to contamination resulting from use. A particularly important area of ​​application for the circular container according to the invention is the purification of previously used washing water, which has preferably been used to clean objects, in particular vehicles, and most particularly the external surfaces of vehicles. The selection of the inlet, outlet, and overflow at different heights is very advantageous for various reasons.The tangential inlet of the water at mid-height initially imparts a circular flow to the incoming water stream, causing it to move in a circular motion around the center of the circular tank. This rotation ensures thorough mixing, prevents short-circuit currents between the inlet and overflow, and ensures a uniform residence time of the water to be purified in the circular tank. The circular motion of the water stream is further assisted to some extent by the Coriolis force.

[0018] A mean height is understood to be a height in the axial direction that is located between the base and the upper edge of the round container in the middle two-thirds of the round container, i.e. approximately between the upper and lower 15 percent of the height of the round container. The height position of the inlet is preferably in the second third in the axial direction of the round container, i.e. in the region of the middle third of the total height of the round container. Particularly preferably, the inlet is located approximately or even almost exactly halfway between the bottom and the upper end of the round container. The horizontal circular flow created by this circular movement is also referred to as primary circular flow. In addition to a circular movement of the water, circular flow is generally understood to mean a rotational flow of the water. Due to the circular movement, the water flow experiences a centrifugal force that drives the water outwards.If the water collects at the edge of the container, the water surface develops a concave shape, with the water at the edge being highest. Due to this water distribution, the hydrostatic water pressure in the edge area of ​​the round container increases and the water in the edge area is moved towards the base or bottom of the round container. Once it reaches the base, the water is moved towards the center of the round container. From the center, the water rises, with any loose dirt particles being held back at the bottom due to gravity. This effect is also known as the teacup effect because when tea is stirred in a teacup, tea leaves collect in the center of the teacup. The rising water is then pushed outwards again by centrifugal force, creating a secondary circular flow oriented perpendicular to the primary circular flow.The secondary circular flow can be seen running along the surface of a torus which is oriented coaxially to the circular tank. The arrangement of the inlet at mid-height allows for an increased residence time of the incoming water in the circular tank and thus improved cleaning due to the teacup effect. The arrangement of the overflow at the upper end of the circular tank ensures that the water flowing in via the inlet at approximately mid-height undergoes at least one primary and one secondary circular movement before flowing out of the circular tank in a cleaned state via the overflow located at the upper end of the circular tank. The tangential arrangement of the overflow promotes or achieves a laminar flow of the outflowing water. In particular, the different levels of the inlet and overflow prevent the occurrence of a short-circuit flow between the inlet and overflow.

[0019] Because the drain, which forms the dirt discharge, is located at the bottom in the center of the circular container, where the dirt particles also collect due to the teacup effect, the dirt particles that accumulate there can be directly removed via the drain. Removal can advantageously take place while the circular container is in operation, i.e., while the cleaning process is running and the water is circulating in the circular container. This advantage is particularly evident compared to a conventional arrangement of a drain on the side of a container. Thus, continuous operation and, in particular, continuous circulation operation can be realized with the circular container according to the invention.Advantageously, the economic use of the water does not have to be interrupted for cleaning; rather, the cleaned water can be continuously fed back into the usage process, and the contaminated water can be continuously fed into the water cleaning process. Continuous cleaning of the water prevents a temporary build-up of dirt or detergents in a closed-loop system, which could potentially impair the quality of the washing process. A further advantage of the circular tank according to the invention is that an increasing flow velocity due to a higher water throughput leads to faster rotation in the circular tank, which intensifies the teacup effect and achieves improved separation of sludge particles.

[0020] The container arrangement according to the invention with a plurality of circular containers according to the invention connected in series has an arrangement in which an inlet of a respective downstream circular container is connected to the overflow of a respective upstream circular container. As already mentioned, the inlet and outlet of each circular container are arranged tangentially and ensure a transfer of laminar flowing water between the individual circular containers. The laminar flow enables the formation of the described teacup effect, so that a particularly low-energy and effective cleaning of dirt particles from the water in the individual circular containers can take place. The series connection of several circular containers significantly improves the cleaning effect compared to using only a single circular container for cleaning the water.As explained in more detail below, the individual round containers can serve different purposes, in particular for the separation of dirt particles of different sizes and types at different stages of the overall wastewater treatment process. In addition to the round containers according to the invention arranged in series in this way, the container arrangement according to the invention can preferably also comprise further containers, which preferably comprise round containers according to the invention and / or round containers of a different type and / or containers of any desired design, which can also be interconnected in other ways.

[0021] The liquid circulation system according to the invention, preferably a water circulation system, in particular for washing water, has at least one container arrangement with at least one container for treating water, in particular washing water. The container arrangement has at least one round container according to the invention, preferably a plurality of round containers according to the invention arranged in series. The liquid circulation system according to the invention, preferably a water circulation system, forms a closed circuit in which a washing process, preferably a washing process of vehicle surfaces, takes place and the liquid contaminated during the washing process, in particular the water contaminated during the washing process, in particular washing water, is cleaned as wastewater in the at least one container arrangement and subsequently discharged as cleaned liquid orPurified water is made available again for the washing process as a usable liquid, in particular as usable water, especially wash water. As already briefly mentioned, the quality of the purified liquid, in particular the purified water, is not impaired by an increased throughput associated with an increased flow velocity of the liquid or wastewater. The liquid circulation system, in particular the water circulation system, is thus, in a sense, self-stabilizing.

[0022] In contrast, conventional water circulation systems with screening or filter systems and low-flow settling tanks function less effectively at increased flow rates than at lower flow rates, so that water quality typically decreases with increased flow rates and a self-stabilizing effect is not achieved.

[0023] In the method according to the invention for liquid treatment, in particular water treatment, preferably for wash water treatment, the liquid to be treated, in particular the water to be treated, preferably the contaminated wash water or wastewater, is first introduced into a circular container via a tangential inlet at medium height. The dirt particles suspended in the liquid, in particular the water, collect at the central point on the bottom of the circular container due to the teacup effect. The dirt particles of the liquid, in particular the water, are then drained off via a drain on the bottom in the center of the circular container. Finally, the purified liquid, in particular the purified water, is drained from the circular container via a tangential overflow at the top of the circular container.The method according to the invention for liquid treatment, in particular for water treatment, shares the advantages of the circular container according to the invention. The aforementioned control device can be used to control the execution of the method according to the invention.

[0024] The liquid circulation system according to the invention, in particular water circulation system, can also comprise a control device for controlling the flow of the liquid, in particular the water, through the container arrangement.

[0025] Parts for controlling the fluid circulation system according to the invention, in particular the water circulation system, can predominantly be implemented as software components in a processor of a computer system for controlling such a fluid circulation system, in particular the water circulation system. This computer system is preferably part of the aforementioned control device in order to control the execution of the steps of the water treatment method according to the invention.

[0026] The control system particularly concerns the control of the throughput volume and flow rate of the liquid, especially water, as well as the removal of dirt particles at the bottom of the circular container, as well as the control of further steps for cleaning the liquid, especially water, explained later. In principle, however, the components of the control system can also be partially implemented in the form of software-supported hardware, such as FPGAs, PLDs, or the like, especially when particularly fast calculations are required.A partial software implementation has the advantage that computer systems and networks already used to control a liquid purification process, in particular a water purification process, can be easily retrofitted by a software update in order to operate in the manner according to the invention in combination with a circular container according to the invention, a container arrangement according to the invention, or a liquid circulation system according to the invention, in particular a water circulation system. In this respect, the object is also achieved by a corresponding computer program product with a computer program that can be loaded directly into a memory device of such a computer system, with program sections for executing control steps for implementing the water treatment method according to the invention when the computer program is executed in the computer system.

[0027] Further particularly advantageous embodiments and developments of the invention emerge from the dependent claims and the following description, wherein the patent claims of a certain category can also be developed according to the dependent claims and description parts of another category and features of different embodiments can be combined to form new embodiments.

[0028] In one embodiment of the circular container according to the invention, the circular container is installed above ground. The circular container is therefore not sunk into the ground as a basin, but rather stands as a container on the floor of a storage area. The storage area itself can be at ground level, underground, or on a higher floor of a building. The circular container is preferably at least partially free-standing so that it is easily accessible from the outside. In particular, this type of installation allows for easy access to the inlet and, if necessary, the outlet / dirt discharge for assembly and maintenance work.

[0029] In one embodiment of the circular container according to the invention, the inlet and overflow are each tubular. A tubular design of the inlet and overflow allows for particularly good laminar flow of the supplied water to be purified and the purified water. A flow that is as laminar as possible promotes the development of the teacup effect, which is used to separate and concentrate dirt particles from the water to be purified in the center at the bottom of the circular container.

[0030] In a preferred embodiment of the circular tank, the inlet and overflow are arranged essentially in the same direction, i.e. parallel to one another. “Essentially” here means that the alignment takes place with the usual design-related tolerances and inaccuracies. Advantageously, a series arrangement of a plurality of such circular tanks can be easily achieved, whereby the circular tanks can be set up in a row. Furthermore, this arrangement in combination with the tangential design of the inlet and outlet can ensure that the inflow and outflow of water takes place without energy loss because the flow direction is maintained and, in particular, the wastewater can be transferred from one circular tank to the next without such energy loss, so that water in the next circular tank is set into a circular motion by its own kinetic energy.It is therefore advantageous to connect several round tanks in series without having to use additional pumping energy to keep the wastewater moving.

[0031] Particularly preferably, the inlet and overflow of the circular container according to the invention are each arranged in the first quadrant of the circular container. Advantageously, a series arrangement of a plurality of such circular containers can be achieved. Due to the different levels of the arrangement of the inlet and overflow and their opposing positioning in a plan view, the water particularly advantageously remains in the circular container longer than with other conventional arrangements, thus promoting the creation of a horizontal and vertical circular flow and thus the teacup effect.

[0032] Preferably, the inlet and overflow of the circular container according to the invention are arranged in one and the same vertical plane. When circular containers are arranged in series, a straight water flow can advantageously be achieved.

[0033] The outlet of the circular container according to the invention, which serves as a dirt discharge outlet, preferably runs vertically downwards. Advantageously, the dirt accumulated in the center of the bottom of the circular container can flow away by gravity when the outlet is opened, without the use of additional pumps. Particularly preferably, the outlet of the circular container according to the invention has a valve for opening and closing the outlet. Advantageously, the flow of the collected dirt can be controlled so as not to impair the formation and effect of the teacup effect.

[0034] Most preferably, the circular container according to the invention is free of internal components. This supports the formation of a laminar, circular flow in the circular container that is as free of turbulence as possible, in order to achieve purification of the liquid in the circular container, in particular the wastewater in the circular container, based on the teacup effect.

[0035] The circular container according to the invention is also particularly preferably configured for continuous flow. This advantageously allows for a continuous purification process for water, in particular wastewater or wash water. In particular, a process requiring continuous water use can be supported by a continuous purification process. A closed-loop operation for the purification and utilization of the purified wastewater can be particularly advantageously implemented.

[0036] In one embodiment of the round container according to the invention, the diameter of the round container is less than 5 meters. Advantageously, the round container has dimensions suitable for accommodating the round container in a closed room with limited space; such dimensions are particularly suitable when a cleaning process is to be implemented using a plurality of round containers connected in series, with a correspondingly increased space requirement, in a building. Particularly preferably, the diameter of the round container is at least 0.5 meters. Advantageously, a minimum residence time is achieved at a predetermined throughput of liquid, preferably water, in particular wastewater or wash water, in order to achieve a good cleaning result.

[0037] In a preferred embodiment of the water circulation system according to the invention, the liquid circulation system, preferably a water circulation system, has a collecting line for collecting liquid to be treated, in particular water to be treated, and for supplying the collected liquid, in particular the collected water, to the container arrangement. There, the collected liquid, in particular the collected water, is treated in at least one round container according to the invention—as already described in detail. Also part of the liquid circulation system according to the invention, in particular the water circulation system, is a return line for returning the treated liquid, in particular the treated water, from the at least one container arrangement.Advantageously, the purified liquid, in particular the purified water, is returned to the process for which the liquid, in particular the water, is used, so that only small additional quantities of fresh liquid, in particular fresh water, have to be supplied from outside into the liquid circulation system, in particular the water circulation system.

[0038] In a preferred embodiment of the liquid circulation system according to the invention, in particular a water circulation system, the liquid circulation system, in particular a water circulation system, and in particular the collecting line has a tub or pit arranged beneath a motor vehicle cleaning system, in particular a car wash or an entire car wash bay, for collecting contaminated wastewater. Advantageously, all of the wastewater generated in one or more washing water circulation systems, in particular in one or more car washes and / or at one or more washing stations, can be brought together and fed to a subsequent cleaning process. Furthermore, the return line of the water circulation system according to the invention is designed to return the treated water from the at least one container back to the motor vehicle cleaning system. Advantageously, the return of the treated water orpurified water into the vehicle cleaning system reduces the water consumption of the vehicle cleaning system.

[0039] In a particularly preferred embodiment of the liquid circulation system according to the invention and in particular of the water circulation system according to the invention, preferably for a motor vehicle cleaning system or a motor vehicle cleaning system, the at least one container arrangement of the water circulation system comprises a first circular container according to the invention for coarse sludge separation, which is connected to the tank. The first circular container for coarse sludge separation is preferably located at a lower level than the motor vehicle cleaning system, i.e., at the same height as an outlet of the tank, via which the first circular container is connected to the tank. Advantageously, the heavier dirt particles, for example sand, which could potentially clog water transport lines or sieves, can be separated right at the beginning of the water purification process.Advantageously, the teacup effect further enhances the effect of gravity, which causes heavy particles to settle relatively easily at the bottom of a tank with little flow and turbulence, so that coarse sludge separation is accelerated compared to coarse sludge separation in a conventional coarse sludge separator and throughput can thus be increased. The first circular tank for coarse sludge separation according to the invention is sufficiently large for a predetermined wastewater volume, a predetermined maximum flow rate and a predetermined maximum level of contamination so that the floating matter and coarse particles undissolved in the wastewater, as well as finer solids, can settle. The first circular tank preferably has approximately the volume that can be passed through the washing hall in one hour at most.

[0040] Preferably the volume is at least 10 m 3and a maximum of 100 m 3 The required tank volume depends on the dwell time and the volume flow, which in turn depends on the washing technology used and the vehicle throughput.

[0041] Thus, in this particularly advantageous variant, the water, in particular the wastewater, remains in the first circular tank for one hour. The water, in particular the wastewater, rotates in the first circular tank through tangential inflow via the inlet, preferably assisted by the Coriolis force (the northern and southern hemispheres differ in terms of the direction of rotation (northern hemisphere: deflection to the right, southern hemisphere: deflection to the left)), and tangential outflow via the overflow, which is preferably oriented in the same direction as the inlet. The direction of rotation of the circular flow is therefore preferably selected so that the circular flow generated by the arrangement of the inlet and outlet and the Coriolis force constructively overlap. However, depending on the size of the circular tank, the strength of the flow, and the latitude, only a minor influence of the Coriolis force on the circular flow is to be expected.The rotation causes a sludge cone to form in the center of the tank bottom. As explained later, this sludge is preferably continuously removed and preferably conveyed to a neighboring sludge storage facility. Since the settling sludge is preferably continuously removed at the outlet, the liquid phase remains consistently large compared to sludge traps in conventional wastewater treatment systems, and thus the average residence time of the water, especially the wastewater, in the first circular tank always remains the same, thereby achieving reliable and consistently good coarse sludge removal. The improved mechanical pre-treatment in the first circular tank helps to protect the technical equipment downstream of the first circular tank, which may be sensitive to sludge.In particular, the liquid circulation system according to the invention, preferably a water circulation system, preferably comprises a pumping station downstream of the first circular container for further transport to a second circular container, with feed pumps arranged therein, into which the pre-treated wastewater from the first circular container overflows. The feed pumps, which may be sensitive to heavy contamination, are protected by the pre-cleaning and their trouble-free operating time is extended.

[0042] The pumping station, which is preferably arranged downstream of the first circular tank, has the task of pumping the wastewater from the first circular tank, which is preferably part of a tank system arranged at a level below the level of a motor vehicle cleaning system, and the pre-treated wastewater from the lower level into a higher area, preferably an area at the level of the motor vehicle cleaning system. Such an area preferably comprises a so-called technical room in which the other circular tanks of the washing water circulation system are arranged. The pumping station preferably has a narrow shaft next to the first circular tank into which the overflowing pre-treated wastewater from the first circular tank flows. Pumps of various power levels and level probes are installed in the shaft.The probes and pumps preferably communicate with a control unit, which is preferably located in a control cabinet and particularly preferably in a control cabinet in the utility room. The level probes continuously measure the liquid level. If the liquid level rises, the control system, preferably via a frequency converter, increases the pump capacity. If the liquid level drops, the pump capacity is reduced. This keeps the liquid level in the pumping station constant.

[0043] In addition, the liquid circulation system according to the invention, in particular the water circulation system, comprises a second circular container according to the invention for fine sludge separation, preferably connected to the first circular container. The aforementioned lifting pumps, which are preferably controlled by frequency converters, can be used to transport the coarsely purified water, in particular wastewater, to the second circular container. The second circular container is preferably located at a higher level than the first circular container. The second circular container is particularly preferably located at the level of the vehicle cleaning system(s). While coarse sludge can settle to the bottom of a coarse sludge container relatively easily due to gravity, fine sludge remains suspended in water, in particular wastewater, for longer.Compared to the conventional approach, in which the water is either diluted by adding fresh water or the dirt in the recirculating system is increasingly concentrated due to slight dilution when fresh water is to be saved, the invention allows fresh water consumption to be significantly reduced by the fine sludge separation in the second circular tank using the teacup effect. At the same time, the water quality of the process water, which is more effectively purified by the fine sludge separation, is significantly improved. Furthermore, the commonly used filter systems, which can easily become clogged, can be reduced.Conventional filtration processes for fine sludge separation, which rely on mechanical filtration processes to separate suspended fine sludge, generally have only limited efficiency due to the required throughput, the required filtration efficiency, and energy consumption for pumps and filters, as well as the increased time required for the filtration and backwashing processes. Conventional fine sludge separators are often supported by the use of chemical flocculants. With the fine sludge separation according to the invention, such flocculants can advantageously be dispensed with. Furthermore, throughput can be significantly increased due to the reduction in the number of inhibiting filter systems. The teacup effect acts as a sedimentation accelerator, particularly in fine sludge separation, without the need for a mechanical filter.Especially when there are small differences in density between water and suspended solids, such as those that occur in fine sludge separation, round tanks that work on the basis of the teacup effect are particularly effective.

[0044] Part of the liquid circulation system according to the invention, in particular the wash water circulation system, is also a container for biological purification, preferably connected to the second circular container. The water, in particular wastewater, purified of undissolved contaminants in the first and second circular containers flows into the bioreactor. This serves for the biological degradation of dissolved contaminants and surfactants in the wastewater. The container for biological purification has filter elements colonized with microorganisms. Such filter elements have a large surface area to achieve the strongest possible filtering effect. The filter elements are preferably filter cubes, also referred to as biocubes, on which the microorganisms are colonized. The filter cubes preferably comprise a plastic material and form a matrix for the microorganisms.After a short run-in phase, a powerful biocenosis develops on the filter cubes, corresponding to or adapted to the nature of the wastewater. The dissolved organic substances contained in the wastewater are almost completely metabolized and degraded by the microorganisms.

[0045] The biological treatment tank preferably has a neutral to slightly alkaline environment, which is achieved using an alkaline pre-cleaner and a citric acid brush shampoo in the car wash. Furthermore, the microorganisms require oxygen, which flows in via demand-controlled aeration units, also known as aeration candles, at the bottom of the tank. Optimized safety technology prevents aeration failure. The rotation of the wastewater in the biological treatment tank and the aeration ensure thorough mixing of the tank contents through targeted fluidized bed flow and simultaneously prevent excessive deposits of contaminants in the tank and on the filter cubes. Rotation of the water flow in the tanks and a tangential inflow also ensure self-cleaning of the tanks.This applies to all containers used in the liquid circulation system, in particular the wash water circulation system, and in particular to round containers.

[0046] By "consuming" surfactants and dissolved contaminants, the microorganisms grow to form an activated film on the filter cubes. The dissolved substances are thereby mineralized. Due to turbulence and friction, the filter cubes continually lose growth, establishing an equilibrium on the filter cubes. The dissolved mineralized growth sinks to the bottom of the circular tank and is carried away as excess sludge. Here, too, a discharge is located in the center of the bottom. Some of the sludge sinks to the bottom and is discharged, while another part remains suspended and is separated in the downstream tank via the teacup effect.

[0047] In addition, the liquid circulation system according to the invention, in particular a water circulation system, comprises a third (or fourth if the bioreactor is included) circular container according to the invention for secondary clarification, preferably connected to the container for biological treatment, and a return line for returning the purified water from the third circular container according to the invention back to the cleaning process for which the liquid circulation system, in particular a water circulation system, is used, preferably to the motor vehicle cleaning system, in particular to the car wash. In the third circular container, the water, which has been subjected to turbulent flow in the container for biological treatment, comes to rest again. The laminar flow again creates a teacup effect, resulting in the sedimentation of abraded biofilm, which is carried away at the bottom of the container via the drain to a sludge storage facility.The third circular tank preferably has an additional outlet for supplying a storage tank or functions as a storage tank itself. The purified water is then pumped from the storage tank to the washing units of the vehicle cleaning system, preferably a car wash or a self-service car wash.

[0048] Preferably, the outlet of the first circular tank, the second circular tank, the biological treatment tank, the third circular tank, and preferably also the feed tank are connected to a sludge storage tank via a pipeline so that the collected dirt, also referred to as sludge, is continuously discharged from these tanks into the sludge storage tank. This consistently removes the sludge from the process water circuit and does not permanently impair the water quality of the washing process, as is often the case with conventional circulation systems. The sludge storage tank is located outside the actual wash water circuit, so that no dirt from the sludge storage tank can reenter the wash water circuit.

[0049] The sludge storage tank is designed so that only a very low flow prevails in the sludge storage tank, figuratively speaking, the sludge can find rest, and thus good sedimentation of the sludge is achieved. By preferably omitting the otherwise conventional flocculants or by reducing the amount of otherwise conventional flocculants, a relatively solid and compact sludge cake advantageously forms in the sludge storage tank, which is disposed of when the sludge storage tank reaches a predetermined fill level, preferably 50 percent of the sludge storage tank's volume. The sludge storage tank therefore receives a small inflow from various containers or circular containers and preferably includes an overflow, which is connected to the first container for coarse sludge separation via a pipeline to create equalization.

[0050] In one embodiment of the method according to the invention for treating liquid, in particular water, preferably wash water, in particular from a motor vehicle cleaning system, preferably a car wash, with a closed wash water circulation system, for cleaning the water, in particular the contaminated wastewater, the water is first drained into a circular container for coarse sludge separation. For this purpose, the water from the motor vehicle cleaning system is first collected in a tub or pit arranged beneath the motor vehicle cleaning system or the car wash bay in which the motor vehicle cleaning system is installed. The floor beneath the motor vehicle cleaning system comprises permeable floor elements, preferably grids, which allow the wastewater contaminated by the washing process to flow from the motor vehicle cleaning system into the tub arranged below.

[0051] As already briefly explained, the wastewater collected in the tank below the vehicle cleaning system is drained via a tank outlet and a pipeline into the first circular tank for coarse sludge separation. The first circular tank for coarse sludge separation is preferably also located at a lower level than the vehicle cleaning system, i.e., preferably lower than the tank outlet, via which the first circular tank is connected to the tank.

[0052] Subsequently, the inventive water treatment method for coarse sludge separation is carried out in the first circular tank. As already explained, the first circular tank is dimensioned accordingly large so that a long average residence time prevails in the first circular tank and sand and similar coarser contaminants can settle at the bottom of the first circular tank due to gravity. Furthermore, the inventive design of the first circular tank, and in particular the tangential introduction of the wastewater into the first circular tank, generates a primary horizontal circular flow and a secondary vertical circular flow, which interact to concentrate suspended dirt particles in the center at the bottom of the first circular tank.This collected dirt is sucked out from the bottom of the first circular container, preferably by using a mammoth pump, and transported into a sludge storage tank, which is emptied by a specialized disposal company when a predetermined filling level is reached, for example half of the maximum volume.

[0053] The pre-treated water is then transferred to a second circular tank for fine sludge separation. The wastewater treatment process according to the invention is carried out in the second circular tank to achieve fine sludge separation. It should be mentioned again in this context that circular tanks operating on the basis of the teacup effect are particularly effective, especially when the density differences between water and suspended solids are small, as occurs in fine sludge separation.

[0054] The mechanically treated water is then transferred to a tank for biological treatment. The mechanically treated wastewater undergoes biological treatment in the tank for biological treatment. The tank for biological treatment can also be designed as a circular tank, with a lateral tangential inflow of water via a tangential inlet being preferred. In this case, the water in the biological treatment tank rotates, which, together with aeration, creates a targeted fluidized bed flow. The fluidized bed flow mixes the tank contents and simultaneously prevents excessive deposits of contaminants in the tank and on the tank's filter cubes.

[0055] Finally, the biologically purified water is fed into a circular tank according to the invention for secondary clarification. In the circular tank for secondary clarification according to the invention, the wastewater treatment method according to the invention is used for secondary clarification of the biologically purified water. The laminar flow generated by the water treatment method according to the invention again creates a teacup effect, resulting in the sedimentation of abraded biofilm, which is carried out at the bottom of the tank via an outlet from the third circular tank to the aforementioned sludge storage facility. Finally, the purified water from the third circular tank is returned to its intended use, preferably in a facility cleaning system, preferably a motor vehicle cleaning system, in particular a car wash, where the purified water is reused for the washing process to clean the surfaces of vehicles.The teacup effect is advantageously used in this variant of the method according to the invention for cleaning different types of suspended particles in wastewater in order to obtain clear, purified washing water or process water which can be reused for the usage process, preferably a washing process, in particular in an object cleaning system, preferably in a motor vehicle cleaning system, preferably a car wash.

[0056] Advantageously, the users of the water in the water cycle, in particular the consumers of the vehicle cleaning system, can be supplied with recycled process water. A fresh water supply to the washing water circuit is required only to a very small extent to compensate for evaporation and carryover losses and preferably occurs during the final rinse cycle of a vehicle wash to optimize the cleaning result. Due to the low fresh water supply, the use of the water, in particular the operation of a vehicle cleaning system equipped with the water cycle system according to the invention, can continue even if washing is prohibited due to a lack of rain.

[0057] Since only a very small amount of fresh water is fed into the water cycle, there is no excess water that would need to be disposed of. Rainwater, particularly in the form of roof water, can be used advantageously as fresh water. Rainwater has a significantly lower water hardness than tap water and is therefore more suitable for car washing, particularly to avoid water spots on the cleaned bodywork. In particular, no softening or desalination, with its correspondingly increased water consumption, is necessary. If little rainwater is produced due to low rainfall, the fresh water can also be replaced with purified wastewater. If necessary, additional wastewater from other sources can also be fed into the water cycle. For example, greywater from households could be fed into the water cycle.

[0058] In the method according to the invention for water treatment, preferably for wash water treatment, in particular of an object cleaning system of an object cleaning facility, preferably a motor vehicle cleaning system of a motor vehicle cleaning facility, with a closed water circulation system, water to be treated, preferably contaminated wastewater, is first collected in a collecting line. The collecting line is preferably part of a tub or pit arranged beneath an object cleaning system, preferably a motor vehicle cleaning system. The water to be treated, preferably contaminated wastewater, is then purified by applying the water treatment method according to the invention. Finally, the purified water is returned to the collecting line for reuse, preferably in an object cleaning system, and in particular to the object cleaning system.A closed water circuit can advantageously be implemented for an object cleaning system, particularly for a vehicle cleaning system, whereby only a very small amount of water needs to be added from outside to compensate for discharge losses, particularly due to water adhering to the objects, especially vehicles, at the end of the cleaning process or due to evaporated water. Thus, the water consumption of the washing process is reduced to a minimum.

[0059] An object cleaning system comprises at least one object cleaning system, preferably a plurality of object cleaning systems. An object cleaning system is understood to be a technical system with which a complete cleaning process of an object, for example a motor vehicle or a bicycle or another object, can be carried out, preferably in an automated manner. Such an object cleaning system preferably comprises a car wash, which has a conveyor device on which an object is moved between several processing stations during a cleaning process, and several processing stations that carry out individual process steps, such as a pre-cleaning process, a main cleaning process, a rinsing process, and a drying process.

[0060] A motor vehicle cleaning facility comprises at least one motor vehicle cleaning system, preferably a plurality of motor vehicle cleaning systems. A motor vehicle cleaning system is to be understood as a technical system with which a complete cleaning process of a motor vehicle can be carried out, preferably in an automated manner. Such a motor vehicle cleaning system preferably comprises a car wash, which has a transport device on which a motor vehicle is moved between several processing stations during a cleaning process, and several processing stations which carry out individual process steps, such as a pre-cleaning process, a main cleaning process, a rinsing process, and a drying process. A motor vehicle cleaning system can also comprise a self-service car wash station, on which cleaning lances are provided, by the use of which a person can clean their vehicle independently.

[0061] In the method according to the invention for liquid treatment with a closed liquid circulation system, in particular for water treatment with a closed water circulation system, the removal of the dirt particles from the round container according to the invention, preferably the first round container according to the invention for coarse sludge separation, preferably comprises a low-turbulence suction process for the dirt particles from the bottom of the round container, which is preferably effected by a mammoth pump. A mammoth pump has a tube immersed in a liquid to be pumped out, into which a gas, usually air, is injected below the liquid level by means of a compressor. A mammoth pump is particularly suitable for lifting solids-laden liquids. Advantageously, the suction of the dirt particles collected at the bottom does not generate turbulence that could disperse the dirt particles in the wastewater.In addition, the mammoth pump has the advantage of not having any easily clogged elements that could impair their function due to the dirt being pumped.

[0062] The invention is explained in more detail below with reference to the accompanying figures using exemplary embodiments. In the various figures, identical components are provided with identical reference numerals. The figures are generally not to scale. They show:

[0063] Figure 1 is a schematic side view of a round container according to an embodiment of the invention,

[0064] Figure 2 is a schematic view from above of the circular container shown in Figure 1 according to an embodiment of the invention,

[0065] Figure 3 is a schematic side view of a motor vehicle cleaning system with a washing water circulation system according to an embodiment of the invention,

[0066] Figure 4 is a schematic view from above of the vehicle cleaning system shown in Figure 3,

[0067] Figure 5 is a flow chart illustrating a wastewater treatment method according to an embodiment of the invention,

[0068] Figure 6 is a flow diagram illustrating a process for wastewater treatment of a motor vehicle cleaning plant with a closed water circulation system.

[0069] Figure 1 shows a schematic representation of the side of a round container 1 for wastewater treatment according to an embodiment of the invention. The round container 1 has a tubular inlet 2 which runs tangentially to a side wall 6 of the round container 1 and is arranged halfway up the round container 1. The wastewater AW to be treated flows clockwise from the inlet 2 (see Figure 2) into the round container 1. An overflow 3 opens out of the round container 1 and is arranged at the upper end of the round container 1 at the maximum height of the water level in the round container 1. Furthermore, the round container 1 shown in Figure 1 comprises an outlet 4 on the bottom 5 in the center of the round container 1. The outlet 4 allows the dirt particles SP collected in the center at the bottom 5 of the round container 1 to be discharged.The peripheral and tangential arrangement of inlet 2 and overflow 3 as well as the Coriolis force of the earth's rotation generates a horizontal circular flow or primary flow S1 (see Figure 2), which causes a centrifugal force acting on the wastewater AW to be treated. Consequently, the water level is raised towards the edge or tank wall 6 of the circular tank 1. The increased water pressure in the edge region of the circular tank 1 caused by the raised water level causes a vertical secondary flow S2, which involves the wastewater flowing downwards in the edge region of the circular tank 1 and subsequently the wastewater AW flowing in at the bottom 5 of the circular tank 1 towards the centre and thus the outlet 4 of the circular tank 1. From there, the wastewater AW flows towards the surface and is guided outwards again into the edge region of the circular tank 1 by centrifugal force.Since the dirt particles of the wastewater AW are somewhat denser than the water in which they are suspended, the dirt particles do not rise with the secondary flow S2 towards the water level, but remain in the area of ​​the outlet 4 at the center of the bottom 5 of the circular tank 1.

[0070] Figure 2 shows a schematic top view of the circular container 1 shown in Figure 1. As can be seen in Figure 2, the inlet 2 and the overflow s open into the circular container 1 in the same quadrant, in Figure 2 in the first quadrant I. Furthermore, Figure 2 shows the tangential arrangement and orientation of the inlet 2 and the overflow 3.

[0071] Figure 3 shows a schematic side view of a motor vehicle cleaning system 21 with a washing water circulation system 20 according to an exemplary embodiment of the invention. The motor vehicle cleaning system 21 has a motor vehicle cleaning system 22, which has a transport device, for example a conveyor belt 8, on which a motor vehicle K is moved between several processing stations during a cleaning process. The washing water circulation system 20 comprises a container arrangement 10 with a total of four round containers 1a, 1c, 1d, 1e, which are involved in the water treatment of the wastewater AW. Of the four round containers 1a, 1c, 1d, 1e, three round containers 1a, 1c, 1e are round containers according to the invention, while a round container 1c used for biological cleaning does not function based on the teacup effect, but can be structurally identical.

[0072] The wash water circuit comprises a coarse sludge trap 1a, which is connected to a trough-shaped hall floor 9 of the vehicle cleaning system 21. The coarse sludge trap 1a comprises a first circular tank. The coarse sludge trap 1a is designed to remove coarse dirt, such as sand grains, from the wastewater AW of the vehicle cleaning system 21. The coarse sludge trap 1a is sufficiently large for the wastewater volume, contamination, and flow rate to allow the undissolved floating matter and coarse particles, as well as finer solids, to settle. The coarse sludge trap 1a has approximately the volume of water that can pass through the vehicle cleaning system 21 in one hour. Thus, the wastewater AW remains in the coarse sludge trap 1a for an average of one hour. The wastewater AW in the coarse sludge trap 1a rotates by tangential inflow clockwise and tangential outflow in the same quadrant.Due to the rotation, a sludge cone forms in the center of the coarse sludge trap 1a, following the teacup effect. A mammoth pump 13 continuously removes the sludge and conveys it into the adjacent sludge storage tank 1f.

[0073] Because the settling sludge is continuously removed from the bottom, the liquid phase always remains the same size, and thus the average residence time of the wastewater (AW) in coarse sludge trap 1a remains constant, enabling consistently effective coarse sludge removal. The effective mechanical pretreatment in coarse sludge trap 1a protects the pumps in the downstream pumping station 14, into which the pretreated wastewater (VAW) from coarse sludge trap 1a overflows. The coarse sludge trap is located underground and has no floor drain.

[0074] The pumping station 14 is responsible for pumping the pre-treated wastewater VAW from the underground basin system upwards into the above-ground technical room (see the upper part of Figure 3 with three circular tanks 1c, 1d, 1e). The pumping station 14 comprises a narrow shaft next to the coarse sludge trap 1a, into which the overflowing pre-treated wastewater AW from the coarse sludge trap 1a flows. Various pumps 11 with different power levels as well as level probes (not shown) are installed in the shaft. The probes and pumps 11 communicate with a control cabinet (not shown) in the technical room. The level probes continuously measure the liquid level in the pumping basin 1b of the pumping station 14. If the liquid level rises, the control via frequency converter ensures an increase in the flow rate of the pumps 11; if the level falls, the flow rate of the pumps 11 is reduced. Thus, the liquid level in the pumping station 14 is kept constant.The pumping station 14 pumps the water AW pre-cleaned in the coarse sludge trap 1a into the fine sludge trap 1c, which is also designed as a circular container.

[0075] The fine sludge trap 1c essentially serves to further sediment undissolved finer sludge. Its overflow 3 flows into a bioreactor 1d, which, unlike the other circular tanks 1a, 1c, and 1d, does not generate a circular flow or a teacup effect. The bioreactor 1d serves for the biological degradation of dissolved contaminants and surfactants in the mechanically treated wastewater (MAW). The circular tank of the bioreactor 1d contains many plastic filter cubes (not shown), also known as biocubes. Due to their large surface area, the biocubes are colonized with microorganisms. After a short run-in phase, a high-performance biocenosis equivalent to that of the MAW wastewater forms on the biocubes. The dissolved organic substances contained in the MAW wastewater are thus almost completely metabolized and degraded.The microorganisms require a neutral to slightly alkaline environment, which is created by using alkaline pre-cleaners and citric acid brush shampoo in the car wash. Furthermore, the microorganisms require oxygen, which flows in via demand-controlled aeration units 12 at the bottom of the tank. The rotation and aeration ensure thorough mixing of the tank contents through targeted fluidized bed flow and simultaneously prevent excessive deposits in the tank and on the biocubes.

[0076] The microorganisms grow by consuming surfactants and dissolved contaminants, forming an aerated film on the filter cubes. Dissolved substances are thereby mineralized. However, the filter cubes continually lose growth due to turbulence and friction between them, so that a growth equilibrium is established. The dissolved mineralized growth partially sinks to the bottom and is discharged as excess sludge into sludge storage 1f.

[0077] From the bioreactor 1d, the water flows into a secondary clarifier 1e, which also serves as a storage tank. In the secondary clarifier 1e, the turbulent, biologically purified water BAW settles again. The laminar flow again creates a teacup effect, which contributes to the sedimentation of the biofilm abraded in the bioreactor 1d at the bottom of the secondary clarifier 1e. The sedimented biofilm is drained from the bottom of the secondary clarifier 1e through an outlet 4, also to the sludge storage tank 1f. A pipeline for draining the biofilm to the sludge storage tank 1f is not shown in Figures 3 and 4 for the sake of clarity. The secondary clarifier 1e has an overflow 3 to supply the washing equipment and thus also serves as a storage tank. The purified water SAW is pumped from the storage tank to the washing units (not shown) of the vehicle cleaning system 22.The outlets of the circular tanks 1c, 1d, and 1e can be used to drain dirt collected at the bottom of the aforementioned circular tanks 1c, 1d, and 1e. The dirt can, for example, be fed to the sludge storage 1f via a pipeline (not shown) and collected there.

[0078] Figure 4 shows a schematic representation of the washing system 20 shown in Figure 3 from above. The motor vehicle cleaning system 22 is not shown in Figure 4. As can be seen in Figure 4, the bioreactor 1d is also designed as a circular container. Although the biological cleaning in the bioreactor 1d is not based on the mechanical teacup effect, which is also prevented by the internals, i.e. the aeration units 12, a horizontal circular flow is generated by the tangential arrangement of the inlet 2 and the outlet 3b of the bioreactor 1d. The rotation of the wastewater in the bioreactor and the aeration ensure thorough mixing of the container contents through targeted fluidized bed flow and at the same time prevent excessive deposits of contaminants in the container of the bioreactor 1d and on the filter cubes.A rotation of the water flow in the container of the bioreactor 1d as well as a tangential inflow also ensure self-cleaning of the container of the bioreactor 1d.

[0079] Figure 5 shows a flow diagram 500 which illustrates a method for water treatment according to an embodiment of the invention. In step 5.I, wastewater AW is first fed into a circular container 1 via a tangential inlet 2 at medium height. In step 5.II, dirt particles from the wastewater AW are collected and removed via a drain / dirt discharge 4 on the bottom in the center of the circular container 1. Finally, the cleaned wastewater SAW is discharged from the circular container 1 via a tangential overflow 3 at the upper end of the circular container 1. Figure 6 shows a flow diagram 600 which illustrates a method for water treatment in a motor vehicle cleaning system 21 with a closed water circulation system 20 according to an embodiment of the invention.

[0080] In step 6.I, wastewater AW of a motor vehicle cleaning system 22 of the motor vehicle cleaning system 21 is first collected in a tray 9 under the motor vehicle cleaning system 22.

[0081] In step 6.II, the wastewater AW collected in the tank 9 below the motor vehicle cleaning system 22 is drained via an outlet of the tank 9 and a pipeline into a first circular container 1a for coarse sludge separation according to an embodiment of the invention. The first circular container 1a for coarse sludge separation is preferably also located at a lower level than the motor vehicle cleaning system 22, i.e., preferably lower than the outlet of the tank 9, via which the first circular container 1a is connected to the tank 9.

[0082] Subsequently, the wastewater treatment method for coarse sludge separation according to the invention, illustrated in Figure 5, is carried out in the first circular tank 1a. As already explained, the first circular tank 1a is dimensioned accordingly large so that there is sufficient residence time in the first circular tank 1a and sand and similar coarser contaminants can settle at the bottom of the first circular tank 1a due to gravity. Furthermore, in particular, the tangential introduction of the wastewater into the first circular tank 1a creates a primary horizontal circular flow and a secondary vertical circular flow, which interact to concentrate suspended dirt particles in the center at the bottom of the first circular tank 1a.

[0083] The wastewater VAW pre-treated in this way is discharged into a pumping basin 1b of a pumping station 14 in step 6. III.

[0084] In step 6.IV, the pre-treated wastewater VAW from the pumping basin 11 is conveyed by a pump 11 of the pumping station 14 into a second circular tank 1c for fine sludge separation according to an exemplary embodiment of the invention. In the second circular tank 1c, the wastewater treatment method according to the invention is carried out to achieve fine sludge separation. The mechanically treated wastewater MAW is then conveyed to a tank 1d for biological treatment. In the tank 1d for biological treatment, the mechanically treated wastewater MAW is biologically treated. The tank 1d for biological treatment can also be designed as a circular tank, with a lateral tangential inflow of the mechanically treated wastewater MAW occurring via a tangential inlet 2.This creates a rotation of the already mechanically treated wastewater (MAW) in tank 1d for biological treatment. This rotation, together with aeration, ensures a targeted fluidized-bed flow. The fluidized-bed flow mixes the tank contents and simultaneously prevents excessive deposits of contaminants in tank 1d and on the filter cubes of tank 1d.

[0085] Furthermore, in step 6.VI, the biologically treated wastewater BAW is fed into a third circular tank 1e for secondary clarification according to an embodiment of the invention. The wastewater treatment method according to the invention, in this case for secondary clarification of the biologically treated wastewater BAW, is applied in the circular tank 1e for secondary clarification. The laminar flow generated by the wastewater treatment method according to the invention again creates a teacup effect, resulting in the sedimentation of abraded biofilm in the circular tank 1e for secondary clarification.

[0086] The abraded biofilm is discharged at the bottom of the tank via a drain to a sludge storage tank 1f.

[0087] Finally, in step 6.VII, the purified water SAW is returned from the circular tank 1e for secondary clarification, which also serves as a storage tank, back to a motor vehicle cleaning system 22 of a motor vehicle cleaning installation 21, for example a car wash, where the purified water SAW is used again for the washing process for cleaning the surface of vehicles.

[0088] Finally, it should be noted once again that the devices described in detail above are merely exemplary embodiments that can be modified in a variety of ways by those skilled in the art without departing from the scope of the invention. In particular, the invention is not limited to the cleaning of motor vehicles, but can also be applied to other vehicles, in particular rail vehicles, bicycles, etc., as well as other objects, such as aircraft, machines, trailers, metal objects, etc. This water treatment system can be used in all sectors where (process) water needs to be cleaned and reused. This means it can be used in all industries, including industry, commerce, livestock farming, fish farming, municipal sewage treatment plants, road drainage, etc.

[0089] Furthermore, the use of the indefinite articles “ein” or “eine” does not exclude the possibility that the characteristics in question may also be present multiple times.

[0090] List of reference symbols

[0091] 1 round container

[0092] 1a Coarse sludge trap / first round tank for coarse sludge separation

[0093] 1b Pump basin

[0094] 1c Fine sludge trap / second round container for fine sludge separation

[0095] 1d Bioreactor / vessel for biological purification

[0096] 1st secondary clarification tank / third round tank for secondary clarification

[0097] 1f sludge storage

[0098] 2 Inlet

[0099] 3 Overflow

[0100] 3a Pump shaft / upward feed to the fine sludge trap

[0101] Motor vehicle cleaning system 22

[0102] 3c Return line

[0103] 4 Procedure

[0104] 5 Bottom of the round container

[0105] 6 Wall of the round container

[0106] 7 Valve

[0107] 8 Conveyor belt / car wash

[0108] 9 tub

[0109] 10 Container arrangement

[0110] 11 Pump

[0111] 12 Ventilation unit

[0112] 13 Mammoth pump

[0113] 14 Pumping station

[0114] 20 (Washing) water circulation system

[0115] 21 (Motor vehicle) cleaning system / object cleaning system

[0116] 22 (Motor vehicle) cleaning system / object cleaning system

[0117] I first quadrant

[0118] II second quadrant

[0119] III third quadrant

[0120] IV fourth quadrant

[0121] AW Wastewater

[0122] BAW biologically treated wastewater K motor vehicle

[0123] MAW mechanically treated wastewater

[0124] 51 Primary flow

[0125] 52 Secondary flow SAW purified water

[0126] SP dirt particles

[0127] VAW pre-treated wastewater

Claims

Patent claims 1. Round container (1) for liquid treatment, preferably water treatment, in particular wash water treatment, comprising: - a tangential inlet (2) at medium height, - a tangential overflow (3) at the upper end of the circular container (1), - an outlet (4) designed as a dirt discharge, on the bottom (5) in the center of the circular container (1).

2. Round container according to claim 1, wherein - the inlet (2) and the overflow (3) are each tubular and / or - the inlet (2) and the overflow (3) are arranged substantially in the same direction.

3. Round container according to claim 1 or 2, wherein - the inlet (2) and the overflow (3) are each arranged in the first quadrant (I) of the circular container (1) and / or - the inlet (2) and the overflow (3) are arranged substantially in one and the same vertical plane.

4. Round container according to one of the preceding claims, wherein - the drain (4) runs vertically downwards and / or - the drain (4) has a valve (7) for opening the drain (4).

5. Round container according to one of the preceding claims, wherein - the round container (1) is free of any fittings and / or - the circular container (1) is designed for continuous flow.

6. Round container according to one of the preceding claims, wherein - the diameter of the circular container (1) is less than 5 metres and / or - the circular container (1) is installed above ground.

7. Container arrangement (10) with a plurality of several circular containers (1) connected in series according to one of the preceding claims, wherein an inlet (2) of a respective downstream circular container (1) is connected to the overflow (3) of a respective upstream circular container (1).

8. Liquid circulation system, preferably water circulation system (20), in particular for washing water, with at least one container arrangement (10), preferably according to claim 7, with at least one container for treating the liquid, in particular the water, wherein the at least one container arrangement (10) has at least one round container (1, 1a, 1c, 1e) according to one of claims 1 to 6, preferably a plurality of round containers (1, 1a, 1c, 1e) arranged in series according to one of claims 1 to 6.

9. Liquid circulation system, preferably water circulation system, according to claim 8, comprising: - a collecting line for collecting water to be treated (AW) for supplying the liquid to be treated, preferably the water to be treated (AW), to the container arrangement (10), - a return line (3c) for returning the treated liquid, preferably the treated water (SAW), from the at least one container arrangement (10).

10. Liquid circulation system, preferably water circulation system, according to claim 9, wherein the collecting line comprises a trough (9) arranged below an object cleaning system (22) and the return line (3c) is designed to return the treated liquid, preferably the treated water (SAW), from the at least one container arrangement (10) back to the object cleaning system (22).

11. Liquid circulation system, preferably water circulation system, according to one of claims 8 to 10, wherein the at least one container arrangement (10) comprises at least one of the following containers: - a first circular container (1a) connected to the collecting line according to one of claims 1 to 6 for coarse sludge separation, - a second round container (1c) according to one of claims 1 to 6, preferably connected to the first round container (1a), for fine sludge separation, - a container (1d) for biological purification, preferably connected to the second round container (1c), - a third circular container (1e) according to one of claims 1 to 6 for secondary clarification, preferably connected to the container (1d) for biological purification.

12. A method for liquid treatment, in particular for water treatment, preferably for wash water treatment, comprising the steps: - introducing liquid, in particular water (AW), preferably washing water, into a circular container (1) via a tangential inlet (2) at medium height, - Removal of dirt particles (SP) of the liquid, preferably water (AW), via a drain (4) at the bottom in the center of the circular container (1), - Discharge of the purified liquid, preferably the purified water (VAW, MAW, SAW) from the circular container (1) via a tangential overflow (3) at the upper end of the circular container (1).

13. The method according to claim 12, comprising the steps: - collecting liquid to be treated, preferably water to be treated (AW), in a collecting line of an object cleaning system (22), - cleaning the liquid to be treated, preferably the water to be treated (AW), by applying the method according to claim 12 in a closed liquid circulation system, preferably a water circulation system (20), - Returning the purified liquid, preferably purified water (SAW), back to the object cleaning system (22).

14. The method according to claim 12 or 13, wherein the cleaning of the liquid, preferably the cleaning of the water (AW), comprises the steps: - Draining the liquid, preferably the water (AW), into a first circular container (1a) for coarse sludge separation, - Carrying out the method according to claim 12 in the first round container (1a) for coarse sludge separation, - Passing the pre-cleaned liquid, preferably the pre-cleaned water (VAW), into a second circular tank (1c) for fine sludge separation, - Carrying out the method according to claim 12 in the second round container (1c) for fine sludge separation, - passing the mechanically purified liquid, preferably the mechanically purified water (MAW), into a container (1 d) for biological purification, - carrying out a biological purification of the mechanically purified liquid, preferably the mechanically purified water (MAW), in the container (1d) for biological purification, - Passing the biologically purified liquid, preferably the biologically purified water (BAW), into a third circular tank (1e) for secondary clarification, - Carrying out the process according to claim 12 in the third circular container (1e) for secondary clarification.

15. The method according to any one of claims 12 to 14, wherein, when carrying out the method according to claim 12 in the round container (1, 1a, 1c, 1e), preferably the first round container (1a) for coarse sludge separation, the removal of the dirt particles (SP) from the round container (1, 1a, 1c, 1e) comprises sucking the dirt particles (SP) from the bottom of the round container (1, 1a, 1c, 1e), preferably by means of a mammoth pump (13).

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