EP1521622A1

EP1521622A1 - Method and device for purifying waste water that is polluted with organic and/or inorganic matter

Info

Publication number: EP1521622A1
Application number: EP03763761A
Authority: EP
Inventors: Jakob Hoiss
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-07-10
Filing date: 2003-07-09
Publication date: 2005-04-13
Also published as: AU2003250005A1; DE20210672U1; WO2004007046A1

Abstract

The invention relates to a method and a device for purifying waste water that is polluted with organic and/or inorganic matter. The invention is characterized in that the waste water is evaporated and condensed within a primary system (13) and a secondary medium (14), preferably untreated water, within a self-contained secondary system (14) that contains a compressor (66) and that is separate from the primary system (13) by evaporating the waste water by heating it on the secondary medium (14) previously compressed in the compressor (66) and further heated up. The steam is guided through a cyclone (58) and the secondary medium expanded in the secondary system (14) is evaporated by condensing the waste water steam. The total waste water fed to the primary system (13) is subdivided into a first partial flow (23) and an at least commensurate second partial flow (24). The first partial flow (23) is brought to a temperature close to the boiling point in a first heat exchanger (28) at the outlet of the primary system through which hot distilled water (31) flows and the second partial flow is brought to a temperature close to the boiling point in a second heat exchanger (38) through which the removed hot clarification (36) flows. The ratio referred to as concentration factor (CF) of supplied total water per time unit to clarification quantity per time unit is selected to range between greater 1 and approximately 20. The inventive method is suited for the thermal reprocessing of waste water and produces germ-free distilled water of high quality and a greater or lesser concentration of the water to be evaporated while saving energy.

Description

Title: Process and device for treating organically and / or inorganically contaminated wastewater

description

The present invention relates to a method and an apparatus for treating organically and / or inorganically contaminated wastewater by distillation.

Fresh and drinking water as well as process water is a valuable raw material that is urgently needed not only in particularly dry climates. Demand is also increasing in industrialized countries. The scarcer existing resources lead to considerable efforts to find new sources of drinking water and to treat non-drinkable water by cleaning it to process or drinking water.

EP-A-0 142 251 describes a thermocompression process for distilling raw water in a single-circuit system. This known method works either in vacuum or only with a slight excess pressure (approx. 0.1 bar above the environment). The reason for this is that the blower or fan described there as compressed does not apply the necessary excess pressure. In addition, their lifespan is much too short, since wastewater vapor with all remaining constituents is more aggressive at higher pressure and thus a higher temperature of, for example, 110 ° Celsius and quickly destroys the compressors corrosively and erosively.

A method and a device for raw water distillation have become known from FR-A-2 337 693 and DE-C-26 00 398, in which raw water which has already been desalinated and demineralized is treated and made into highly pure, germ-free Distillate is processed, being about the same Amount of distillate is generated as raw water is fed to the device. In this method, a dual-circuit system is used such that the raw water within a primary system and a secondary medium within a secondary system containing a compressor, separate from the primary system and self-contained, are evaporated and condensed, the raw water being further heated by heating the previously in the compressor Secondary medium at overpressure and this evaporates in the secondary system by condensation of the water vapor and the water vapor is passed through a cyclone. However, this known method is only suitable for the distillation of raw water which has already been desalinated and de-mineralized, but not for organically and / or inorganically contaminated waste water. If such wastewater were to be supplied in an appropriate amount to this known device, the primary system would clog in a very short time.

The object of the present invention is therefore to design a method and a device of the type mentioned at the outset in such a way that it is suitable for thermal wastewater treatment, aseptic water distillate of high quality with at the same time more or less low concentration of the wastewater to be evaporated and yet energy-saving to create.

To achieve this object, the features specified in claim 1 or in claim 11 are provided in a method or a device of the type mentioned.

With the measures according to the invention it is achieved that a low concentration of the waste water in the primary system can be achieved on the basis of a choice of the value of the concentration factor CF determined in preliminary tests for each waste water type, which means that the treatment takes place in an optimal range. This means that it is enough Add relatively small amounts of additives, which contributes to the protection of the environment, in order to prevent crystal formation of the anhydrite in the primary system combined with the impractical property here of essentially accumulating in the apparatus. This low concentration in conjunction with the high blowdown rate also prevents a significant increase in the boiling temperature in the primary system during operation, which in turn has an advantageous effect on the design of the compressor in the secondary system. Since the two-circuit system used works in overpressure, no pumps are necessary to suck off the distillate, so that the distillate remains in the purity in which it leaves the primary system. This condensation process also gives excellent fresh water quality. The type of distillate production using cyclone separation results in a practically aseptic water distillate. Because the distillate is free from germs and salt, it can be used for a wide variety of purposes after appropriate conditioning.

A preferred range for the CF value results from the features of claims 2 and 12, respectively.

Further advantageous configurations result from the features of claim 3 or 13 and 4 or 14 and of claims 5 and 15.

An increase in the flow rate in the evaporator improves the heat transfer coefficient in the evaporator, has a low tendency to form deposits on the evaporator walls, and has a low tendency to corrode, since deposits that play an important role, for example, in stress crack corrosion in gaps, are prevented from forming , also smaller dosing quantities, if additives for anti-scaling are required, and a higher circulation factor in the evaporator leads to a longer dwell time of the waste water at the evaporation temperature, so that the F _Q value (measure of the sterilization quality of the process) is increased. This ensures that the microorganisms in the wastewater are killed much more safely than is the case with only a short residence time.

Further procedural configurations result from the features of one or more of claims 6 to 10.

In one embodiment, it is achieved according to the features of claim 16 that a boiling temperature which is only slightly above the temperature of the preheated partial streams is achieved by a heater integrated in the two-circuit system.

In another embodiment, a heating device which is external to the dual-circuit system is provided in accordance with the features of claims 17 and / or 18, so that an adaptation to the respective energetic conditions at the installation site can be achieved.

Since all parts of the system are exposed to aggressive wastewater, a corrosion-resistant, pitting-resistant design of the heat exchangers is achieved in accordance with the features of claim 19.

With the features of claim 20, a further increase in the flow rate in the evaporator and thus a further improvement of the positive process variables mentioned is achieved.

According to the features of claim 21, a metering station for the admixture of an additive in a relatively small dosage is provided.

When using drinking water applications is one Follow-up of the distillate is necessary because the consumption of large quantities of distilled water disturbs the mineral balance of the human body. Certain minerals and the like must therefore be given to the drinking water according to the WHO standard. are fed. When using the water distillate for irrigation of agricultural systems, no post-treatment is necessary. The low mineral content prevents rapid salinization of the soil due to the salt entry through the irrigation water. The soils remain fertile for a long time without the need to replace the soil or to rinse the soil. However, if desired, special additives such as fertilizers, insecticides and the like can be added to the distillate. This can be carried out in the alternative manner described above with the aid of the features according to claim 22.

In order to achieve a simple start-up of the device according to the other embodiment, the features according to claim 23 are provided.

With certain waste water, foaming can occur on the evaporation surface. In order to destroy this foam, the features of claim 24 are provided in a further embodiment, wherein the construction can be carried out according to the features of claim 25 or 26.

Further details of the invention can be found in the following description, in which the invention is described and explained in more detail with reference to the exemplary embodiments illustrated in the drawing. Show it:

1 shows a schematic representation of a flow diagram of a device for thermal overpressure waste water treatment according to a first embodiment of the present invention, characters

1A and 1B each show a variant of the first exemplary embodiment,

FIG. 2 shows a representation corresponding to FIG. 1 of a device for thermal overpressure wastewater treatment in accordance with a second embodiment of the present invention,

2A shows sections of a variant of the second exemplary embodiment and

Figure 3 in an enlarged schematic representation of that part of the device which contains the two-circuit process system.

The device 11 or 11 'shown in the drawing in accordance with two embodiments of the present invention is used for energy-saving thermal overpressure wastewater treatment, wherein top quality germ-free water distillate is produced, and the device is designed in particular for small to medium-sized outputs. The germ-free water distillate should serve in particular as drinking water, process water or for irrigation. In the embodiments shown, a dual-circuit system 12 or 12 'with a primary system 13, 13' working under slight overpressure for the wastewater to be treated and a spatially separate, self-contained secondary system 14, 14 'is used, which is operated under excess pressure by means of a heat pump ,

According to the first embodiment of an overpressure wastewater treatment device 11 shown in FIG. 1, wastewater to be treated is discharged via a pipeline 16 which is immersed in the feed tank in a manner not shown a pump 17 is conveyed through a filter system 18 in front of it, in which coarse particles of, for example, larger than 200 μm are removed from the cold waste water. The pump 17 is designed in such a way that the cold wastewater sucked in is increased in pressure to the extent necessary to overcome all pressure losses in the device 11 and a desired residual overpressure is still present at the device outlet. After the pump 17 there is an overpressure of, for example, about 2 to 3 bar, while on the outlet side there is a slight overpressure of, for example, about 0.25 to 0.30 bar at the distillation column, or about 0.1 bar after the last heat exchanger 38 , After the pump 17, the pipeline 16 is connected to a metering station 19, via the connecting line 21 of which an additive is added to the waste water. The additive, which only has to be added in relatively small amounts, serves to reduce or change the crystal formation of anhydrite (CaSo ₄ ) or the scale formation or to avoid it altogether or, if necessary, to prevent foam growth and thus an overgrowth of components , in particular to prevent the evaporator in the dual-circuit system 12. This additive is selected depending on the use of the water distillate; For example, it must also be approved for drinking water production and be environmentally compatible.

The pipeline 16 branches after a distributor 22 into a first feed line 23 and a second feed line 24, in each of which a throttle element 26 or 27 is provided. As a result, the wastewater stream supplied in the pipeline 16 is divided into a first sub-stream in the first feed line 23 and a second sub-stream in the second feed line 24. The two sub-streams are quantitatively divided by the two throttling members 26 and 27 in a stationary or regulated manner.

One side of a first heat exchanger 28 is connected into the first feed line 23, the other side of which is in one Distillate line 31 is located, which is connected to the output end of the primary system 13. The section 33 of the first feed line 23 emerging from one side of the first heat exchanger 28 is connected to the input-side end of the primary system 13, ie a distillation still 29, into which the first partial flow of the waste water is introduced.

Thus, while the primary system 13 of the two-circuit heat pump system 12 is fed with a partial volume flow of the wastewater to be treated, the secondary system 14 is self-contained and has, for example, raw water in the form of fresh water as a secondary medium. In a manner not shown, the secondary system 14 can be connected to a closable pipeline for the first supply of secondary medium. In the still 29 of the primary system 13, an external heater 32 is installed, which can be operated electrically here.

At the bottom, the distillation bubble 29 of the primary system 13 is connected to an exhaust pipe 36 into which the other side of a second heat exchanger 38 is inserted. Wastewater blowdown is removed from the free outlet-side section 37 of the discharge pipeline 36. In other words, the discharge pipeline 36 is used for the return of untreated or non-evaporated waste water. The second feed line 24 is connected to one side of this second heat exchanger 38, so that the second partial volume flow flows through the second heat exchanger 38 and is likewise introduced into the distillation still 29 of the primary system 13 via the outlet-side section 34 of the second feed line 24.

The distillate line 31 is connected at its outlet section 35 to a conditioning station 39, via the connecting line 41 of which conditioning agent is supplied to the aseptic water distillate of the highest quality. The type of conditioning agent depends on what the water distillate should be used for, i.e. whether it should be used as drinking water or process water or used for irrigation. For example, various minerals and salts are provided as conditioning agents in one case or, for example, fertilizers or the like in the other case.

The heat exchangers 28 and 38 shown schematically in FIG. 1 are heat exchangers made of titanium using removable plate exchanger technology, which have high efficiency due to small wall thicknesses and pressure losses and high corrosion resistance and can be produced in a very economical manner.

Before the thermal overpressure wastewater treatment is dealt with using the device 11 shown in FIG. 1, the mode of operation of the two-circuit heat pump system 12 will first be described with reference to FIG. The wastewater entering the primary system 13 through the two feed lines 23, 33 and 24, and 34, and the first and second heat exchangers 28, 38 to in countercurrent to the distillate emerging from the distillate line 31 or to the blowdown emerging from the discharge pipeline 36 preheated just below the distillation temperature, as mentioned, reaches the distillation still 29, which is arranged below a first heat exchanger 52, which works in the primary system 13 as an evaporator. From the distillation bladder 29, the waste water to be treated rises into the evaporator area 54 of the first heat exchanger 52, advantageously also made of titanium, which is designed, for example, in the form of a corrugated surface evaporator. The distillate vapor generated in the so-called tubes of the evaporator area 54 of the first heat exchanger 52 rises and passes through a cyclone 56, in which the separation of entrained droplets and particles due to a very high centrifugal acceleration of the steam takes place. Due to a physical effect, only a small amount of water forms between the inner wall of the cyclone and the distillate vapor, which migrates into the lower part of the cyclone 56 due to the internal flow field and therefore does not get into the distillate. The converging water is discharged via a bottom-side pipe 57 (approx. 0.2% of the distillate output of the plant). It is also possible to return this water directly under the liquid surface to be evaporated. This has the advantage that no line (possibly with a throttle valve) has to be routed outside the two-circuit heat pump system 12 or 12 '. The distillate vapor itself does not come into contact with the metal surface at the critical points of the highest speed, but passes through the immersion tube 58 attached in the middle of the cyclone 56 into a second heat exchanger 62, which acts as a condenser in the primary system 13. In this second heat exchanger 62, which is also designed, for example, in the form of a corrugated surface evaporator / condenser, the steam emerging from the cyclone 56, for example after a change in direction by 90 °, flows through the so-called gap spaces between the upright corrugated surface plates and condenses in the process. The condensate in the form of the wastewater distillate leaves the primary system 13 via the distillate line 31 with a slight positive pressure.

The heat of condensation of the primary medium (seawater or seawater vapor to be desalinated) which is released in the primary system 13 on the second heat exchanger 62 acting as a condenser is used to carry out evaporation of the secondary medium in the secondary system, which is fed into the secondary system 14 only once. The resulting secondary medium vapor in the secondary system is transferred via a conventional droplet separator, not shown, from the upper part of the dual-circuit system 12 into a compressor 66, which is operated by a Electric motor 50 is driven, guided. Compression and an associated temperature increase take place in the compressor 66. The vapor of the secondary medium leaving the compressor 66 is hot enough to serve in the first heat exchanger 52, which acts as an evaporator in the secondary system 14, essentially as the sole heating medium for evaporating the preheated filtered waste water. By condensing the vapor of the secondary medium in the first heat exchanger 52, the waste water is evaporated there. The resulting condensate of the secondary medium leaves the first heat exchanger 52 and reaches the upper second heat exchanger 62 via a pipe 68 and a throttle valve 65, which works in the secondary system 11 as an evaporator. The condensate of the secondary medium flows into a bottom region of the second heat exchanger 62 and flows as steam through the heat exchanger tube spaces vertically upwards and from there via the tube 67 back to the compressor 66. It is understood that the two systems 13 and 14 are completely separate from one another are separated and that the two heat exchangers 52 and 62 are formed in a corresponding manner.

According to the embodiment shown in FIG. 1, the wastewater is fed into the device 11 at approximately 15 ° C., for example a total volume flow of 12.3 m ³ / h being achieved with the aid of the pump 17. The two throttling members 26 and 27 are set such that the first volume flow in the first feed line 23 is approximately 3.0 m ³ / h and the second volume flow in the second feed line 24 is approximately 9.3 m ³ / h. The size of the first volume flow in the first feed line 23 is determined by the distillate volume flow in the distillate line 31, specifically here in such a way that the two volume flows are approximately equal. The distillate emerging from the primary system 13 of the dual-circuit system 12 at a temperature of approximately 107 ° C. and flowing through the first heat exchanger 28 causes the first volume flow in the first feed line 23 Flow through the first heat exchanger 28 has reached a temperature of approximately 105 ° C. and enters the distillation still 29 of the primary system 13 at this temperature. The distillate cools to about 20 ° C and emerges at about 0.1 bar. The second volume flow in the second supply line 24 is heated in the second heat exchanger 38 to a temperature of likewise in the range of 105 ° C, since through this second heat exchanger 38 the sludge flowing out of the still 29 at about 110 ° C through the second heat exchanger 38 flows. The blowdown has cooled to approximately 19 ° C. at the end of the second heat exchanger 38 and emerges at approximately 0.1 bar. The blowdown volumetric flow emerging from the distillation still 29 of the primary system 13 has the same size as the second volumetric flow in the second feed line 24, ie is approximately 9.3 m ³ / h. After heating to about 105 ° C., with which the two volume flows enter the distillation still 29, the wastewater heated in this way is brought to the boiling temperature with the aid of the external heating 32, which is in the primary system which is under pressure

13 is about 110 ° C. The temperature difference remaining for the evaporation is, as mentioned, applied by the heat pump circuit of the secondary system 14. In a manner according to the invention, the method for thermal overpressure wastewater treatment is operated at a low concentration and thus a high blowdown rate. Here, a concentration factor CF, which represents the ratio of the total feed quantity of wastewater to the amount of blowdown, is set in the range between large 1 and approximately 20. To set the CF value, this is determined in preliminary tests depending on the type of waste water. In conventional known waste water, this CF value is between greater than 1.4 and 10. With a small (for example CF slightly larger than 1.4) selected CF, the risk of corrosion and the risk of deposit formation on the evaporator surfaces within the primary system 13 or within the device 11 relative low. The device therefore operates in an area just above the saturation line of anhydrite, so that additives have to be added in very small amounts via the dosing station 19. This CF value results in a high wastewater circulation due to the resulting high blowdown rate. This improves the heat transfers in the distillation system 13 and also prevents the formation of deposits in the system.

The device 11 according to FIG. 1 is started in such a way that the distillation still 29 of the primary system 13 is filled with wastewater to be treated to the usual level and is heated to approximately 110 ° C. with the aid of the external heating 32. Then the compressor of the secondary system 14 is switched on, so that the thermal process for overpressure waste water treatment can begin.

The device 11 'shown in FIG. 2 according to a second embodiment for the thermal overpressure wastewater treatment in order to produce top-quality germ-free water distillate in an energy-saving manner corresponds essentially in terms of system technology and process engineering to the device 11 according to FIG. 1. Those components which are both part of the device 11 and the device 11 'are used in a corresponding manner, are therefore given the same reference number and a line in FIG. 2. The differences between the two devices 11 'and 11 consist in particular in the fact that the design of the external heating for accompanying and starting the process is designed in different ways. Another difference lies in the higher distillate production per unit of time and thus in the predetermined higher volume flows. The device 11 'according to FIG. 2 also works with a concentration factor CF in the range between greater than 1 and approximately 10. A filtered (filter 18 ') waste water volume flow of 41 m ³ / h is conveyed through the pipeline 16' with the aid of the pump 17 '. After the addition of additives (metering station 19 '), a first volume flow of 10 m ³ / h in the first feed line 23' and a second volume flow of 31 m ₃ / h in the second feed line 24 are achieved with the help of the throttling members 26 'and 27'' generated. The first volume flow is heated in the first heat exchanger 28 'by the distillate flow, which is about 107 ° C, from 10 m ³ / h to about 100 ° C and brought into the distillation still 29' of the primary system 13 '. The second volume flow is brought in the second heat exchanger 38 'from the approximately 110 ° C hot blowdown flow of 31 m ³ / h from the still 29' to about 100 ° C as well. This second volume flow through the section 34 'of the second feed line 24' is now not conveyed directly but indirectly via one side of a third heat exchanger 78 and a pipeline 79 to the distillation still 29 'of the primary system 13'. At the outlet of the third heat exchanger 78, the second volume flow of 31 m ³ / h has a temperature of approximately 113.3 ° C. Mixing the two volume flows results in a mixing temperature of the waste water to be evaporated in the distillation still 29 'of approximately 110 ° C., which corresponds to the boiling temperature in the primary system 13'. Evaporation also takes place here with the aid of the heat pump cycle of the secondary system 14 '.

The third heat exchanger 78 is part of a heating device 81 which carries a heat transfer medium, for example oil, in its circumferential pipeline 82, 83, which is circulated by a pump 84. This heat transfer medium flows both through the other side of the third heat exchanger 78 and through one side of an oil- or gas-heated boiler 86. In the boiler 86, the heat transfer medium, whose volume flow is, for example, 36 m ³ / h, is heated to 135 ° C. and is after

Pass through the third heat exchanger 78 to about 111 ° C cooled down.

According to FIG. 2A, according to a variant, instead of a circuit with a heat transfer medium and an oil or gas-fired boiler 86, a conventional steam generator 86 'can be used for water vapor. The saturated water vapor generated (at, for example, a temperature of 118 ° C.) reaches the third heat exchanger 78 as the heating medium via the pipe 83 and there - while condensing at the same time - heats the second volume flow on the opposite side through the section 34 ′ of the second feed line 2 'indirectly to the temperature still missing in the process (e.g. to 113.3 ° C). The resulting condensate is fed back to the steam generator 86 'via the pipeline 82. Due to a local arrangement adapted to the hydrostatic conditions (e.g. so low below the third heat exchanger 78 that the hydrostatic pressure of the condensate is sufficient to return it even into the steam generator without external energy), the pump 84 shown in FIG. 2 is omitted.

The compressor 66 'of the secondary system 14' is not driven with the aid of an electric motor as in the exemplary embodiment according to FIG. 1, but with the aid of a diesel unit 87 which also drives a generator 88 which supplies electrical energy for controlling the device 11 'and the drive which supplies pumps, valves and the like.

To start the device 11 'according to FIG. 2, a bypass 71 is provided for the second heat exchanger 38'. For this purpose, a bypass line 72, which is equipped with a shut-off valve 73 and a pump 74, runs between the discharge pipeline 36 'and the section 34' of the second supply line 24 '. In addition, a valve 75 is in the flow direction after the bypass line 72 in the exhaust pipe 36 'and in the flow direction before the bypass line 72 in Inlet section 34 'installed a shut-off valve 76. To start the process, the still 29 'is first filled with wastewater above the usual level in order to have enough water for the heating phase. When the valves 75 and 76 are closed and the valve 73 in the bypass line 72 is open and the pump 74 is switched on, wastewater is circulated via the third heat exchanger 78 into the still 29 '. With the heating device 81 switched on, work is carried out in these valve positions until a suction pressure of approximately 0.1 to in the distillation still 29 '

0.2 bar, corresponding to a boiling temperature of about 110 ° C. Thereafter, the compressor 66 'in the secondary system 14' is switched on and at the same time the valves 75 and 76 are opened and the valve 73 is closed and the pump 74 is switched off.

It should also be mentioned that in this embodiment the distillate emerges from the distillate line 31 at a temperature of approximately 25 ° C. at a pressure of approximately 0.1 bar and a volume flow of 10 m ³ / h. The blowdown stream of 31 m ³ / h has a temperature of about 24 ° C and exits section 37 'of the exhaust pipe 36' at an overpressure of about 0.1 bar.

In both of the exemplary embodiments described above, in addition to determining the CF value from the preliminary test, the density and the viscosity of the medium to be evaporated can also be measured during the evaporation. Observations of possible foam formation on the evaporation surface of the primary medium are also recorded according to variants. If increasing foam growth is determined, then a suitable chemically active defoamer is either added to the incoming wastewater to prevent it (see device 19 or 19 according to FIGS. 1 or 2 or it is controls the foam formation according to the variants shown in FIG. 1A or IB with the aid of a mechanically acting foam destroyer measure. This can be done, for example, with a type of propeller or turbine 91 that rotates above the liquid surface in the distillation still 29 (FIG. 1A) and is driven by a motor 92 and destroys the foam bubbles. As a further or different mechanical foam destroyer, a nozzle system 94 can be used, which is located above the evaporation surface in the distillation still 29 '(FIG. IB) and which has not yet evaporated (i.e. liquid medium) from the lower part in the two-circuit heat pump system 12 or 12'. by means of a pump 95, sucked in and sprayed with overpressure (for example 5 bar) horizontally or from above into the foam via the nozzles and thus destroys it.

Is the waste water in terms of its inclination, at the selected concentration (and selected

Evaporation temperature) to form deposits, not critical, so larger CF values (e.g. larger than 1.4 to 10) can be selected. This has the advantage that the amount of blowdown becomes smaller and thus the exchange surface of the heat exchangers 38 or 38 'for the recovery of the heat energy is smaller and thus saves investment costs. A continuous density and / or viscosity measurement installed in room 29 or 29 'monitors the CF value determined in the preliminary test, at which the concentrated medium still remains flowable, or the apparatus 12 or 12' at the determined process temperatures and process pressures. and 38, or 38 'not clogged.

A conductivity meter (probe) built into the pipeline 37 or 37 'can also be used to monitor the CF value and thus also to easily control the volume flows.

Claims

claims

1. A method for treating organically and / or inorganically contaminated wastewater, in which the wastewater within a primary system and a secondary medium, preferably raw water, within a secondary system containing a compressor, separated from the primary system and evaporated and condensed, is evaporated by the wastewater evaporated by heating on the secondary medium previously compressed and further heated in the compressor, then the waste water vapor is passed through a cyclone and the secondary medium expanded again in the secondary system is evaporated by subsequent condensation of the waste water vapor, and in which the total waste water stream fed to the primary system is converted into a first partial stream and dividing a second at least equally large partial flow, of which the first partial flow in a first heat exchanger through which hot water distillate flows at the outlet of the primary system and the second partial flow in one drawn off from the first n hot blowdown through which the second heat exchanger flows is brought to a temperature close to the boiling point in the primary system and that the ratio of the total amount of water supplied per unit time to the amount of blowdown per unit time, referred to as the concentration factor (CF), is chosen between a value of greater than 1 and a value of approximately 20 becomes.

2. The method according to claim 1, characterized in that a concentration factor (CF) between a value of greater than 1.4 and 10 is selected.

3. The method according to claim 1 or 2, characterized in that the value of the concentration factor (CF) is determined in a preliminary test according to the type of waste water and then adjusted.

4. The method according to at least one of claims 1 to 3, characterized in that the density and viscosity of the waste water to be evaporated is determined in a preliminary test.

5. The method according to at least one of the preceding claims, characterized in that a defoaming agent is supplied to the incoming wastewater.

6. The method according to at least one of the preceding claims, characterized in that the size of the distillation stream and the size of the second partial stream is chosen approximately equal to the size of the blowdown stream.

7. The method according to at least one of the preceding claims, characterized in that the second partial stream is heated again, to a temperature above the boiling point in the primary system such that the mixture of the first and second partial stream has the boiling point prevailing in the primary system ,

8. The method according to at least one of the preceding claims, characterized in that the waste water is passed through a circulation evaporator located in the primary system.

9. The method according to at least one of the preceding claims, characterized in that an additive for preventing the crystal growth of anhydrite is supplied to the total wastewater stream in relatively small amounts.

10. The method according to at least one of the preceding claims, characterized in that the aseptic water distillate is conditioned.

11. Device for treating organically and / or inorganically contaminated wastewater with a primary system (13; 13 ') for the wastewater and a separate, closed secondary system (11; 11') containing a compressor (66; 66 ') for heat transfer, the primary system (13; 13 ') being coupled to the secondary system (11; 11') by a first heat exchanger (52) for evaporating the waste water and a second heat exchanger (62) for condensing the waste water vapor, and with an in Vapor chamber of the primary system (13; 13 ') between the evaporator 52) and the condenser (62) arranged cyclone (56), characterized by a total wastewater flow fed to the primary system (13; 13') into a first partial flow and a second partial flow dividing distributor (22; 22 '), through a first heat exchanger (28; 28') through which the hot water distillate at the outlet of the primary system (13; 13 ') flows, in which the first partial flow a temperature close to the boiling point in the primary system (13; 13 ') can be brought through a second heat exchanger (38; 38') through which the withdrawn hot blowdown flows, in which the second partial flow can be brought to a temperature close to the boiling point in the primary system (13; 13 '), and by two Upstream throttling devices (26, 27; 26 ', 27'), via which a concentration factor (CF), the ratio of the total amount of water supplied per unit of time to the amount of blowdown per unit of time, between a value greater than 1 and a value of approximately 20 is adjustable.

12. The apparatus according to claim 11, characterized in that a concentration factor (CF) between a value of greater than 1.4 and 10 is adjustable.

13. The apparatus of claim 11 or 12, characterized in that the value of the concentration factor (CF) in a preliminary test according to the determined type of

Waste water is adjustable.

14. The device according to at least one of claims 11 to

13, characterized in that the density and viscosity of the waste water to be evaporated is determined in a preliminary test.

15. The device according to at least one of claims 11 to

14, characterized in that a station (19, 19 ') for adding a defoaming agent is connected to the incoming wastewater.

16. The device according to at least one of claims 1 to

15, characterized in that a heating device (32) is provided in a distillate still (29).

17. The device according to at least one of claims 1 to

16, characterized in that a third heat exchanger (78) is provided, through which the second partial flow in the second feed line (24 ') flows on the one hand and on the other hand is part of an external heating device.

18. The apparatus according to claim 17, characterized in that the oil or gas-operated heating device is provided with a forcibly circulating and the third heat exchanger (78) flowing heat transfer medium.

19. The device according to at least one of claims 11 to 18, characterized in that the heat exchanger (28, 38; 28 ', 38') in plate exchanger technology

Titanium are made.

20. The device according to at least one of claims 11 to

19, characterized in that the evaporator (52) in the primary system (13; 13 ') is formed by a circulation evaporator with natural or automatic or with forced liquid circulation.

21. The device according to at least one of claims 11 to

20, characterized in that the pipeline (16; 16 ') supplying the total amount of water is connected to a metering station (19, 19') for supplying an additive.

22. The device according to at least one of claims 11 to

21, characterized in that the distillate line (31; 31 ') is connected to a conditioning station (39, 39').

23. The device according to at least one of claims 11 and

22, characterized in that the second heat exchanger (78) is provided with a lockable bypass (71).

24. The device according to at least one of claims 11 to

23, characterized in that a mechanically acting foam destroyer (91; 94) is provided in a distillation still (29) above the evaporation surface.

25. The device according to claim 24, characterized in that a motor-driven propeller element (91) is provided as the foam destroyer.

26. The apparatus according to claim 24, characterized in that a nozzle system (94) is provided as a foam destroyer, applying a liquid medium with excess pressure.