DE2455633A1 - PROCESS AND SYSTEM FOR PURIFYING WASTE WATER - Google Patents

Description

Process and system for the purification of waste water

The invention relates to a method and an installation for the purification of wastewater as well as a suitable ozonization sound tower. Generally concerns the Invention the purification of wastewater and in particular a wastewater treatment system and a wastewater treatment plant, that or which meets the requirements that commonly used in plants and systems for so-called third-degree wastewater treatment or tertiary wastewater

509828/0771

TELEPHONE (Ο8Θ) S3 QB ea

TELEX OB-Ü938O

TELEGRAMS MONAPTH

cleaning are provided.

In pending U.S. patent application with the current Number 136 404 by David Bybel et al. for a wastewater treatment process and device assigned to the assignee of the present application a new cleaning or treatment process for wastewater described and claimed, to which the steps sonication and ozonization of the treated wastewater. For the present invention, the by Bybel et al. Invention described the starting point. The invention deals with a new wastewater purification system and a new wastewater treatment plant using the Bybel et al. is also used. In this system, the effect of the ozone sound treatment is combined with others physico-chemical treatments optimized. The invention also relates to a device for treating Wastewater with ozone and sound, the effect of which compared to that of Bybel et al. described and claimed is improved.

According to the invention a method for purifying Wastewater with entrained solids and dissolved impurities proposed, which is characterized in that the wastewater added a coagulant is that a polyelectrolyte is added to the wastewater to form a flaky precipitate, that the wastewater then passed through a plate structure to remove a significant portion of any solids suspended therein, and that the Sewage then ozone and sound energy with a strength. exposed to the generation of cavitation in the wastewater is sufficient, the wastewater being cavitation

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not later than the time cius is set, too which it encounters an effective concentration of ozone.

A cleaning system is also provided for in the invention proposed by wastewater, which is characterized by an equalization basin, a settling basin, a weir in the Settling basin, a device for transferring waste water from the equalization basin to the weir, a Device for adding a coagulating agent to the Settlement basin, a flocculation basin, an underwater weir that separates the / sedimentation basin and the flocculation basin and enables the sewage to flow from the sedimentation basin into the flocculation basin, means for adding polyelectrolyte into the wastewater near the underwater weir, a device for slow stirring of the wastewater in the flocculation basin, a clarifier, a second underwater weir that allows the sewage to flow from the flocculation basin to the Clarifier allows, the clarifier a Outlet has a plate structure in the clarifier between attached to the second underwater weir and the outlet is and. serves to remove suspended solids from wastewater, a vertical one Ozonization sound tower with an inlet "near its upper end and an outlet near its bottom, means for transferring waste water from the outlet of the clarifier to the inlet of the tower, a device for feeding ozone into the tower, a Device for applying sound energy to the Tower, which is below the inlet of the tower and above the device for feeding ozone into the Tower is arranged and sound energy of such strength

50 98 28/0771 BADOHlGiNAL

can apply that this is sufficient to generate cavitation in / vbwasser within the tower.

Furthermore, according to the invention, an ozonization sound system is used proposed, which is characterized by a perpendicular outer side wall, _ the one vertical space is limited and. an inlet port for sewage near the top and an outlet for sewage near the bottom, one Device for feeding ozone into the tower and a device for applying sound energy on the tower, the underhaJ-b of the inlet of the tower and above the device for feeding in ozone is arranged in the tower and can apply sound energy of such strength that it is used to generate Cavitation in the wastewater within the tower is sufficient.

Thus, the invention is based on a new .Verfahren for Wastewater purification is preferably directed entirely with the help of physico-chemical means. the The invention relates to both the method and the plant. When the wastewater enters the facility, will it is subjected to comminution or sieving, for example by means of a sand trap or the like, or both and then fed to an equalization basin, which serves as a reservoir, thus for an essentially constant one Flow through the rest of the facility is ensured. The wastewater then flows to a settling tank, and when it leaves the settling tank, a coagulant such as ferric chloride is added. then The wastewater runs into a flocculation basin, where a polyelectrolyte is added and the resultant generated Flakes mostly fall to the bottom, from where the mud

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is eliminated. The partially treated wastewater is then by a plate structure, which is preferably a Has a unique design and is directed to a filter. The clarified and filtered wastewater is then a unique ozonization sound system. Chamber fed where it is before or at the same time with the ozonization is exposed to ultrasonic vibrations of cavitation strength. Preferably the ozonization sonication tower so divided into sections that the treated wastewater has two different frequencies the sound energy is set. After the treatment in the ozonization tower, the drainage Liquid can be dispensed or fed to ozone contact basins for further ozonization.

The invention is thus a waste water purification system third degree, in which the wastewater is subjected to physico-chemical processes. The sewage - is made with a coagulant and a Treated polyelectrolytes and then clarified in a plate structure, which is preferably a unique one Construction has * The treated wastewater is then filtered and passed through an ozonization sonication chamber in which the liquid flows counter to the ozone. Inside the tower the liquid is exposed to a sonication of considerable strength or energy, sufficient to generate cavitation before it encounters high concentrations of ozone or at the same time. After the ozonization sonication treatment the outflowing liquid can be released or lexted through an ozone contact chamber.

BAD ORfGJNAL

509828/0771

2A55633

Embodiments of the invention are shown in the drawings and will be described in more detail below explained. Show it:

Fig. 1 is a partially schematic plan view a wastewater treatment plant according to the invention;

FIGS. 2A and 2B show a hydraulic flow diagram the system according to FIG. 1 when FIG. 2B is attached to the right of FIG. 2A?

Fig. 3 is a schematic diagram showing the particle flow between the plates of a Plate structure, shows;

4 is a schematic plan view of one in one plate structure arranged in a circular container;

FIG. 5 shows a schematic vertical section through the container according to FIG. 4;

6 shows a schematic plan view of a plate structure arranged in a rectangular container;

7 shows a vertical section through the plate structure according to FIG. 6;

Fig. 8 is an enlarged plan view of the in the

System according to FIG. 1 used plate structures?

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SAD ORIGINAL

2Ä55633

Pig. 9 shows a section according to 9-9 in FIG. 10 shows a section according to 10-10 in FIG. 8;

11 is a plan view of a preferred embodiment of the invention Plate structure *

Fig. 12 is a fragmentary plan view of da3

Plate structure shown in Fig. 11 in enlarged Scale;

13 shows a section according to 13-13 in FIG.

FIG. 14 is a view similar to FIG. 9 showing the shows a modified plate structure according to the invention;

15 shows a section along 15-15 in FIG. 14t

16 shows a side view of a device according to the invention Ozonization sound tower;

17 shows a section according to 17-17 in FIG. 16;

Fig. 18 is a view, partly in section, showing shows the placement of the low-frequency transducers in the ozonization sound tower; and

19 shows a plan view of the holding plate for the low frequency converters.

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The following is a detailed description of the drawings. The wastewater treatment plant for carrying out the method according to the invention is generally with the Reference numeral 10 denotes. This system 10 comprises a waste water supply line 12 in which a shredder 14 is arranged, an equalizing foam 16, · a settling basin 18, a flocculation basin 20, a clarification basin 22, a collecting basin 24, a filter system 26, an ozonization-sonication column 28, an ozone contact tank 30, a dwell tank 33 and a waste water discharge 34. How will emerge from the following, the wastewater flows through the system one after the other in the sequence indicated.

Any suitable form of grinder 14 can be inserted into the sewer supply line 12, for example a pulp mill or any other device which serves to grind large particles entrained in the inflow into smaller particles which can be more easily processed. Furthermore, although this is not shown, the sewage supply line 12 can also contain necessary pumps for pumping the inflow into the sewage treatment plant. The type of grinder used herein does not form part of the invention and any of a large number of known grinders can be used to this end. Instead of the shredder sand traps and / or Zuflußsiebe known A, can _r t are used to larger particulates from the waste water to remove in order to ensure the fact that the entrained and dissolved in waste water residues have a particle size suitable for treatment by the system is. These devices are also well known.

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The system to be described below is only an example of a system that basically has the features of the invention. The size of the plant, their specific design and arrangement, as well as their effectiveness, are a matter of design in view on the special nature of the inflow to be treated Sewage and its amount. Thus, it should be understood that the specific system described here is an example and is not intended to limit the basic principles and improvements included in the will be described below.

The system shown in Figures 1 and 2 is like this Designed to process or process 600,000 gallons (2,271,264 liters) of domestic wastewater per day. can clean. After processing by the shredder or the sieve 14 is the sewage feed line the inflow into the equalization basin 16 from. The purpose of the equalization basin is to compensate for inflow peaks, which occur periodically during the day, and also that of the inherently balanced system to provide treated wastewater with the greatest possible degree of uniform quality. This means that the The contents of the inflow can change during a period of 24 hours and that the purpose of the compensation tank consists in making the wage fluctuations wider equalize, so that the rest of the system has to process wastewater with as constant a quality as possible. As has already been mentioned, the equalization basin also serves as a reservoir for a relatively constant The aim is to ensure that the sewage flows through the rest of the system. '

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As can be seen from Figures 1 and 2, the floor is of the equalization pool 16 inclined towards the front central area, the slope of three separate floor sections is formed, namely a central section 38 which extends from an end face 40 to the central region 36 runs, and two side sections 42 and 44 which run obliquely from the sides towards the center. The tapering one Liquid is introduced into the equalization pool at its top, and after it has stayed in the equalization pool, it is drawn through a pump suction line 46 removed approximately in the area of the central base 36, so that largely any solids, during the dwell time in the equalization pool may have settled, be withdrawn «Preferably in the equalization basin 16 there is an overflow skimmer 48 is provided, also shown, with the open inlet end 50 of the skimmer at the desired position The level of the wastewater is arranged in the equalization tank, so that all oil, all scrap or all Solids floating on the surface can be slowly drawn off. The skimmer 48 is over yet facilities to be described with a. Pump 52 connected to the flowing through the skimmer 48 Will direct material into the sludge and sludge removal system of the plant. The sludge and sludge removal system will be described in more detail below.

As can best be seen from FIG. 1, the equalization basin 16, the settling basin 18, are the flocculation basin 20 and the clarifier 22 are all rectangular in plan; these basins have common walls between themselves, which in certain cases serve as weirs, with it

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Wastewater, from one basin to the neighboring basin can overflow. The wall 54 that the basins 16 and 18 but does not have this function. As already mentioned, the equilibrium tank 16 outflowing liquid drawn from the zone 36 in its central bottom through a suction line 46, which with a pair of pumps, preferably centrifugal pumps 56, of which two are shown here, ■ however, one is preferably used at a time and the other is in reserve. For the expert lies it is obvious that a suitable valve mechanism 58 is provided, the line 46 to the inlet of a of the pumps 56 leads * The outlet of the pump 56 is denoted by the reference sign 60 and gives the balanced, inflowing liquid into a weir 62, in which it is preferably an adjustable saw tooth weir. The inflow to the settling basin 18 collects in weir 62 and runs in a known manner over the cattle in the sedimentation tank. Before the inflowing liquid is fed into the weir 62, however, the line a suitable coagulant metered in such a way that its intensive admixing is ensured, so that vii Ie initial flakes are formed in the sedimentation basin 18, while the wastewater is held in this sedimentation tank. The coagulant can be one of many well-known Koagul! identify act, for example around alum, ferrous chloride, ferrous sulfate, aluminum chloride etc. At present, ferric chloride is preferred as the coagulant. If ferric chloride is used, should the amount between about 30 and 70 milligrams per liter of waste water and preferably about 50 milligrams each Liters of wastewater. It is clear to those skilled in the art that other amounts of coagulant would be used, though

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another coagulant would be used. Furthermore is It is known to those skilled in the art that the particular coagulant used depends on the type of sewage. For the usual types of household sewage? has however Ferric chloride proved extremely suitable.

An adjustable overflow 64 is arranged in the settling basin 18 and leads back to the equalizing basin 16. Of the adjustable overflow is provided to control the flow of wastewater through the basins 18, 20 and 22 of the wastewater treatment plant 10. As is known, will thus, by raising the level of the inlet or top of the overflow 64, less wastewater will be discharged the settling basin 18 is returned to the equalization basin 16, thereby causing more wastewater. flows to the basins 20, 22 and 24, whereby the flow rate to the collecting basin 24 is increased. if in the opposite case, the upper end of the pipe 64 is lowered, more wastewater is in the settling tank 18 to Equalization basin returned, so that the flow rate from the settling basin to the flocculation basin, Clarification basin and finally to the collecting basin "

As can be seen most clearly in Figures 1 and 2, the bottom of the sedimentation basin has the shape of an inverted one Pyramid, 'so that there is a collection area for the removal of sludge that goes to the bottom of the Falls to the sludge collection area 66 via its converging walls. The eliminations of the Sludge from the area 66 takes place by means of a suction line 68 which is connected to the inlet of a pump 52 for removal of mud from area 66 leads. With the suction line 68, the line 48 is connected, which proceeds from the equalization basin 66, as described above. Consequently

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The pump 52 draws particulate matter from both exits. the same basin as well as from the bottom of the sedimentation basin. It should be noted that there is a skimmer 70 in the settling basin 18, the top of which is located approximately level with the surface of the sewage in the settling basin. The skimmer 70 performs a function which is quite similar to the function of the skimmer 43 in the equalization basin, which is to remove any scrap, oil, fat or other floating matter on the surface of the sewage in the settling basin. The lower end of the skimmer is preferably connected via a valve Ii to the line 68 and from there to the inlet of the pump 52. The outlet from the pump 52, indicated by the reference numeral 74, is connected to a sludge line 76 which leads to a sludge bed, not shown.

The mean residence time for the wastewater in the sedimentation basin takes about 20 minutes, although it varies depending on the condition of the sewage will be. During the time that the wastewater is in the settling tank, there is a weak one Circulation due to the flow of liquid through it the settling basin from the equalization basin to the flocculation basin. This, along with the way in which that Koagulierraittel is introduced, in order to ensure an even distribution of the coagulant in the wastewater To ensure settling basins so that a uniform formation of initial flakes is relatively easy ringer size is promoted.

The wastewater from the sedimentation tank flows together with the

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EntangsfJöckch.en carried along, which were generated by the reaction of the • wastewater with the coagulant, for example ferric chloride, from the settling basin by flowing around a semi-cylindrical partition 78, which is mounted ^{on a partition 80 between the settling basin 18 and the flocculation basin 2O -} "and is open at the top and bottom. The upper end of the partition 78 preferably protrudes above the surface of the waste water in the equalization basin and settling basin, so that it is ensured that all of the liquid that is in the space between the partition 78 and the wall 80 flows in, flows through the lower end of this space. In the space between the wall 80 and the partition 78, a pipe 82 is arranged, which serves to feed a polyelectrolyte into the waste water in this space. The purpose of this polyelectrolyte is, large, to produce heavy flakes from the initial flakes produced by the coagulant in the manner previously described the type of polyelectrolyte depends on the type of coagulant and the sewage itself. For common household sewage, which has a pH of about 7.2 to 7.3 and where the coagulant is ferric chloride as previously described, an excellent polyelectrolyte is a high molecular weight anionic polyelectrolyte such as that from the Company "Carus" is sold under the name AP 91. Doses of approximately 0.5 mg / l have been found to be extremely effective. However, it is clear that the invention is in no way limited to this particular polyelectrolyte or a system with ferric chloride and · an anionic polyelectrolyte of high molecular weight, as these

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Figures are only given as preferred examples of household wastewater are made of the specified nature and are not intended to be limiting.

To ensure the even distribution of the polyelectrolyte. to pump in the wastewater while it flows from the sedimentation basin into the flocculation basin are the wings 86 of a conventional stirrer 84 in the space between the wall 80 and the septum 78, preferably approximately at the level of the feed of the polyelectrolyte "in this space, so that the polyelectrolyte quickly and evenly in the wastewater is distributed as it flows through this space * When the sewage with the polyelectrolyte over a Underwater weir 88, which forms the bottom of an underwater channel 90 in wall 80, is therein already distributed polyelectrolyte * to promote the growth of the flakes. It should be noted that the width of the weir 88 is equal to the diameter of the semi-cylindrical septum 78 and within the space that is limited by the septum, is arranged so that it is ensured that all liquids, that flow from the sedimentation basin into the flocculation basin, through the space behind the. Partition wall flow must and be provided with polyelectrolyte.

As can easily be seen from a consideration of Figures 1 and, the _; Inner shape of the flocculation basin 20 is essentially the same as the shape of the settling basin 18. Thus, the bottom of the flocculation basin 20 also has a pyramid shape, so that a deepest collecting zone 92 is formed, which is located at the inlet end of a sludge suction line 94 which connects to the inlet

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a mud pump 96 is connected, the outlet 90 of which is connected to the hose instructions via a suitable valve 100 connected is. As can best be seen in Fig. 2, a skimmer 102 is also provided in the flocculation basin 20, the upper end 104 'of which is arranged near the surface of the wastewater in the flocculation basin and its lower end is connected to the sludge suction line 94 so that it leads to the inlet of the pump 96. In addition to Presence of the polyelectrolyte in the flocculation basin is the main difference between the flocculation basin and the settling basin in that a slowly rotating stirrer 106 is provided, which is preferably has a pair of spaced apart wings 108 and 110 and is used to drain the wastewater in the flocculation basin to impose a slow circular motion so that it is possible that the growing flakes are in the Merge flocculation basins through contact with other flakes. The speed of the circular motion must be very low, for example on the order of 2 to 3 rpm, to ensure that the flakes connect on contact and not tear through the shear forces that result from the velocity gradients in the circular flow. The dwell time in flocculation basin 20 is preferably about 20 minutes, although, as has already been done in view on the sedimentation basin was mentioned, this depending on the type of sewage and the flow volume to the particular Time can be different.

To prevent the flakes that grow in the flocculation basin in the manner described above from breaking up, while 'the liquid with the entrained flakes flows from the flocculation basin to the clarifier

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the width of the underwater weir 112 between the flocculation basin and the clarification basin is proportionate

"large compared to the width of the underwater weir 88 between the sedimentation basin and the flocculation basin. As can best be seen in Figures 1 and 2, the underwater weir 112 is the underside of an elongated channel 114 in a wall 116 between the Flocculation basin and the clarifier. Since those in the ■ liquid that flows between these two basins, entrained flakes have grown to a considerable size, the speed gradient must be as small as possible are held to prevent the flakes from being crushed by the shear force that results from the velocity gradient at the weir: this is achieved by the weir 112 in comparison to the width of the / weir 88 is wider. The wastewater and the flakes carried over by the underwater weir 112 flow, flow into the clarifier between the wall 116 and a septum 118, the runs down from above the surface of the liquid in the clarifier. This ensures that all of the liquid flowing from the flocculation basin into the clarifier first goes to the lower one Must flow portion of the clarifier so that they flow under the lower end 120 of the partition 118 through can. This will put the fluid in the right place brought and a flake cover is generated below the bottom of a plate structure 122, which is provided for this purpose is to separate the flakes that pass through the flake cover from the liquid. The construction of the plate structure is new and represents one of the characteristics of the invention and will be described later. Suffice it to say that the Liquid with the flakes carried upwards through

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the plate structure flows between adjacent plates, which all have an angle to the horizontal and vertical, and that during this flow the flakes out of the liquid and fall onto the plates, allowing the clarified liquid to pass through the Top of the plate structure 122 flows out and through an outlet pipe 124 in a wall 126 between the clarifier 22 and the collecting basin 24 flows. Thus, the liquid in the collecting basin 24 becomes very low Entrained solids content, and the solids that are still present become only one have very small particle sizes as larger and heavier particles will be eliminated from the plate structure 122. The removed solids fall onto the plates of the plate structure 122 and slide due to the force of gravity down along the plates and eventually fall to the bottom of the pyramidal clarifier where they are withdrawn from a hose 126 'leading to the inlet of a pump 128, the outlet of which connected to the mud line 76, as shown in FIG Fig. 1 can be seen. With the inlet of the pump 128, a skimmer 130 is also connected, the upper The end is arranged approximately at the level of the surface of the liquid in the clarifier and which has the purpose of Skim off oil, fat, scum or any other floating material on the liquid in this basin.

The sump 24 serves as a reservoir for the clarified liquid that is pumped through the rest of the system must be, i.e. through the 31ter installation 26, the Ozonator sonicator 28 and the ozone contact basin 30.

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The pumps for drawing off the clarified liquid from the sump 24 are indicated by the reference number designated, wherein in Fig. 1 two pumps are shown. In fact, one pump is enough to run the Flow off, but two are provided so that there is a standby pump. Hence they are different Valve means 134 are shown, which are used to select which of the pumps 132 to be determined Time is used. The inlet to the pumps 132 is indicated by the reference numeral 134 and is at the bottom of the Collection basin 24 arranged. On the outlet side of the Pumps 132 there is a pressure regulating control valve 136 of known type, which by controlling the back pressure of the pump 132, the flow rate through the valve 136 can control, as is known. Thus, the crowd can of the liquid flowing through valve 136 can be held constant, which is desirable and preferred will. It should also be noted that although not shown, it is preferred to use the sump to assign a conventional level control, which is used to switch on the pump when the level of the Liquid in the collecting basin 24 a certain, predetermined Height exceeds, and shut off the pump 132 if the level of the liquid in the collecting basin 24 drops below a certain lower level.

After the pump 132 has passed the clarified liquid through the Control valve 136 has pumped the liquid into two filters 26, each of these filters preferably is a filter with mixed filter media, both sand and filter anthracite, i.e. fine grained Anthracite. The filters 26 are preferably

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wise to the well-known type of filter, which is a depth filtration achieve what this is commonly called. Such a depth filtration preferably leads to that the filtering effect takes place over the entire length of the filter path and that solid ones removed from the filter Particles from the filter media over the entire length of the Filter path are retained. Although such depth filtration using a filter with mixed It should be noted that other filter shapes can be used without the frame to leave the invention. As can be seen from Fig. 1, the filters 26 are operated in parallel, so that half of that pumped by one of pumps 132 Liquid flows through each of the filters. However, valve devices are used for flushing or other maintenance work 138 provided so that all of the liquid can be caused to flow through a filter, while the other is being flushed, serviced or the like. * As already stated, however both operated at the same time.

As previously mentioned, the clarified and filtered liquid from the outlet of the filters 26 is passed through a Sonication-ozonization tower 28 passed. The acoustic ozonation tower 28 can be of the type described in the cited Bybel et al. described and claimed and particularly shown in Figures 1 and 2 thereof, with the sewage inflow in these Figures of the outflow from the filters 26 is. A significant increase in the effectiveness of the sonication ozonization process has been observed, that in the aforementioned Bybel et al. is described, noted when this is combined with a sewage treatment system,

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as previously described here- The significant improvement in this combination results from the Fact that the particles on which the ozonization sonication chamber acts, a size and composition that are unique to the Ozonization sonication treatment is suitable, whereby its effectiveness is greatly increased. How yourself As will be apparent from the following description, the ozonization sonication tower 28 is of a different type than that of Bybel et al. described, and-this Construction is detailed in connection with Fig. 16 in this Description to be described. At this point it should be sufficient to state that the a line 140 from the sonication-ozonation tower 28 flowing liquid can already be free of germs, which eliminates the need for further treatment of this fluid. .

Depending on the type of wastewater treated and its In certain cases, however, the liquid can have a volume when it emerges from the ozonization sonication tower 28 cannot be sterile, and in these cases ozone contact basins 30 are preferably provided through which the liquid flowing out from the ozonization sonication tower 28 flows for the purpose of further ozonization, thus the considerable sterility of the system flowing liquid in the outlet chamber 32 is ensured. As best seen in Figures 1 and 2 As can be seen, therefore, the outlet line 140 from the ozonization sonication tower 28 divides into three branches 144, each of which leads to a weir 146 at the top of one of the ozone contact basins 30. At the bottom of the Ozone contact basin 30 is a central manifold

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arranged, from the six pipe branches with ten branch lines 150 each extend, namely 76.2 cm in one direction and 76.2 cm in the other direction. The branch lines 150 are porous. Ozone for the ozone contact basins 30 and the ozonization sound reinforcement tower 28 can be generated by any suitable ozone generator that converts air or oxygen to ozone can. The selection of a specific ozone generator and a specific gaseous medium for the conversion is a matter of economic considerations and depends on the particular system. The ozone generator as such is not part of the invention. Suffice it to say that the ozone generator is sufficient Must have capacity so that the liquid in line 142 has an excess of ozone, preferably a residual ozone content of 0.1 to 0.2 milligrams per liter and preferably more than 0.15 milligrams j.e liters, which increases the likelihood that any oxidizable material that passes through the contact ozonization chamber 30 flows, has been oxidized by the ozone. However, it should be noted that the amount of excess ozone in the liquid in line 142 should be very small, since a too large excess ozone has certain adverse environmental effects.

If the ozone contact chambers 30 are used, as is presently preferred, it will be seen that preferably six of these can be provided, the six chambers in three parallel groups of each two series chambers are arranged. The residence time of the liquid in each chamber should be about half a time Hour so that the liquid passing through each

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the two chambers arranged in series flows, one is in contact with ozone for a full hour. As stated earlier, the ozone contact chambers can 30 will, however, then be unnecessary if the from the ozonization sonication chamber 28 leaking liquid meets the quality requirements for. the outflowing Liquid in line 142 have been placed. In this case, the ozone contact chambers be bypassed completely or left out of the system if so desired.

The introduction of ozone into the ozonization sonication tower 28 and into the ozone contact chamber 30 creates a foam which contains a substantial amount of ozone and which tends to rise to the top of the tower 28 and chambers 30. This foam can from the top of the tower 28 by means of a. Schaumabführlaitung and withdrawn from the upper end of the chambers 30 by means of foam discharge lines 156, all of these lines lead to a foam collecting line 158 which leads to a foam liquefaction tank and the inlet. Have a pump 160 (Fig. 1) and the outlet of the pump 160 go into the sludge line 76 so that sludge in the sludge line 76 is ozonated to prevent the growth of anaerobic bacteria therein. This is a desirable feature of the present invention Systems ; however, it is optional. Instead of using the ozone in the manner described, if pure oxygen is the starting material for the ozone, the excess ozone could be passed back through the ozone generator 152 in a known manner, or it could be passed to a gas retention tank (not shown), in which it could convert to oxygen and then be released into the atmosphere. If with repatriation

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a dryer should of course be inserted in the return path to keep moisture Will get removed.

As FIGS. 1 and 2 show, the discharge line leads 142 to an indwelling basin 32, which is optional with the present invention. So the discharge in the Line 142 drained directly into a stream or into the sea via the after the treatment described so far Soil can be distributed or released in a similar manner without adverse effects occurring. To the legal However, compliance with regulations and implementing provisions of certain state governments may an indwelling basin 32 may be required, and one is provided in the system described. The residence time of the liquid in the residence basin 32 is preferably on the order of about 50 minutes, although, as has already been stated, this is not essential unless certain Implementing ordinances must be met. Apart from the fact that the linger basin 32 statutory regulations State administrative authorities met, there is an advantage to the addition of a basin 32 to the system in that it provides a source of clean water for rinsing the filters 26 therewith can be cleaned periodically after they have been used during normal operation as described above, have accumulated a significant amount of solids. It can be seen that therefore a pair of pumps' 162, two of which are shown here, so that a reserve pump is provided, with only one for the flushing process is required, its inlets in the retention basin and that the outlets. of pumps over Control valves 164 are connected to a line 166,

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which leads to the control valves 138 of the filter 26. By operating the control valves correctly, the Filters 26 are regularly rinsed or washed in succession, which means that clean water is out of the line 166 is passed through the filter in the opposite direction to the normal direction of flow so that thereby any trapped solids dissolved and be eliminated. The washing liquid with the eliminated Solids from the filter being washed is passed through line 168 to equalization basin 16, from where it can again participate in the cycle through the entire system in the manner already described. For it will be clear to those skilled in the art how to operate the valves 138 so that one filter at a time is washed while the other filter is kept in normal operation.

The plate structure is described below.

The plate structure which is preferably used in the method and system according to the invention is in the Figures 6 to 8 shown, in which the plate structure is shown in detail. As is true of all plate structures, plate structure 122 is off a plurality of parallel, angled plates 200 constructed, which are spaced D from each other, have. The angle at which the panels are oriented or inclined and their spacing as well the flow rate through the plate structure can ' optimized so that the greatest possible amount of in the liquid flowing into the plate structure Partial material carried along is removed. This optimization depends on the geometry of the container for the plate structure, the flow throughput of the system

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and the largest allowable particle size in the downstream Liquid. The design of an optimal plate structure for these given parameters is determined by a mathematical and physical analysis given below. The invention is based on a thorough theoretical analysis of the fundamental principles contained in these sedimentation devices act for both upflow and downflow. In particular, the invention relates to the optimal construction of such devices, i.e., them provides equations which define the angle of inclination of the substantially flat and parallel plates with the Length of the panels. And possibly other parameters in such a functional relationship that the Amount of solids in a given container size or for a given size of floor space, whose normal points in the direction of the gravitational vector, can be removed, is as large as possible. For this In the invention, the reference vector is either vertical or horizontal, depending on the orientation of the container, and it points in the direction of flow. With essentially flat plates are both ordinary, straight smooth surfaces as well as corrugated plates and plates that are slightly curved for reasons of strength, as well as subdivided ones Plates meant as will be described below. Parallel panels also close the case one that the space between the plates is wedge-shaped, but the wedge angle must be small.

This invention provides derived principles Equations that quantitatively describe the separation process of the parallel plates that are inserted into the solid area are describes. These equations set the rate of descent of the smallest particle, that of the Device is to be completely eliminated,

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Drawing on construction parameters, for example the The angle of inclination of the panels, the length of the panels and the distance between the panels. In the event that a rectangular device in a circular area is to be incorporated, the optimization is also carried out with regard to the size of this rectangle. These optimizations are carried out below for many typical configurations, with both Upflow and Downflow for the installation of parallel plates in both vertical and vertical horizontal containers are also taken into account. Both rectangular and circular containers or available Floor areas are considered. In the case of circular A rectangular sedimentation device is placed in the container.

As already mentioned, the invention applies to both “for rectangular as well as circular containers, arranged either in a vertical or horizontal position are. It also applies to settlers with upflow, in which the suspended solids be removed from the same end of the plates where the inflowing liquid enters, as well the downflow case where the suspended solids are removed from the plate at the same end become like the clarified liquid. Because the derivative for the equations that are applicable to the particular case, with the exception of certain "algebraic" signs and trigonometric functions are the same, this derivation is detailed for the case only the upward flow in a circular, perpendicular Container carried out. The equations obtained for the other cases are merely reported by general equations are given for

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the optimal design of any sedimentation device can be used. The appropriate parameter selection for each individual case will be specified.

In order for the functioning of these settling devices to be understood, the physical processes must be understood the settling process that takes place between the parallel plates can be described quantitatively. Fig. 3 shows the potential paths that a particle can follow as it travels through the space between the plates 200 is transported by the fluid flow. How out of this Figure can be seen, some of these particles with low sedimentation or downward velocity. Keiten carried out from the space between the plates without sedimentation taking place. By vector summation of the two velocities involved, namely the fluid velocity and the sedimentation velocity, the following components become for. get the velocity of a given particle in the x-direction and in the y-direction:

y component "2 V

1 -

ν cos α (1)

x component

ν _χ = v _t sin α (2)

For these equations, the reference vector for angles and lengths points upwards in the vertical direction: for the more general cases, which will be summarized later, the reference vector in the direction of the container

509828/0771

2Ä55633

axis or its equivalent in the case of limited Show area. In equations (1) and (2) above, ν is the mean fluid velocity in the space between the plates, v. the rate of descent of a given Particle moving through this space and D is the distance between the plates. The velocity profile is the laminar flow between the plates, as is the case with low Reynolds' views. This laminar flow or a low Reynolds number must be maintained to allow effective sedimentation. The downward or countercurrent the suspended solids is believed to be negligible - as is the case for disposal of particles from slurry with low concentrations of suspended solids applies.

Figures 4 and 5 show a rectangular plate forming device 122 inserted into a circular container C and such a basin, respectively. As can be seen, the area available for flow through the rectangular area is less than that of the circular container. For a given speed v _{q of} the upward flow in the container, the speed of the upward flow in the right-angled area is given by the following equation:

ftf tp-

^V b = V 2 *. ^v o Ο) -

a FR - a.

Where R is the radius of the sedimentation tank and a is the length of one side of the sedimentation device. The entry surface into the plate structure is smaller than the area of the circular

509828/0771

shaped container inserted rectangle. The defeat between the upward speed v, in the rectangle and the upward velocity ν into the plate structure is given by the following equation:

^v c ^{= V} b. .

Where L is the height of the sedimentation device and α is the angle of inclination of the plates. The vertical upward velocity ν at the entry into the plate structure stands for the mean velocity ν of the fluid between the plates in the following equation reproduced relationship. This follows from the fact that the velocity vectors are in different directions point.

v _a = v _c / cos α , (5)

By back substitution, the velocity components of a particle can be in the x-direction and y-direction (see Fig. 3) as a function of the upward speed obtained in the container, the rate of descent and the construction parameters for the Plattengebilclevorrichtung will:

y component

V .. = "Ζ

ο "J 9 " i / 0

(a-L tan a) (R * ~ -a) 'cos α

v.cosa (6)

x component

V _x = v _t sin α (7)

509828/0771

These equations that the sedimentation phenomenon describe quantitatively, are then used to set up the equations for an optimal interpretation of the Sedimentation device used. . "-

In principle, it would be preferable to use a plate forming device to be interpreted so that when it is inserted into the circular container, it is as large as possible Amount of suspended. Solids removed. In order to achieve this goal, precise knowledge is required the probability distribution of the particle sinking velocities in the inflowing suspension. Since this information is seldom known and, if known, is subject to experimental errors, another, approximate optimization target must be selected v / earth.

As an approximate optimization goal, the smallest value of the particle size could be determined, which is still completely as the particles pass through the space between the plates, this is a determination of the smallest value of the particle sinking speed • equivalent. A particle is considered here (Fig. 3), whose particle trajectory begins at point χ = -D / 2 and y = 0 and ended at point χ = D / 2 and y = L

-; el

Depending on the parameters of the plate forming device, ie. the angle of inclination, etc., and the upward _{velocity v o} , a particle with a certain critical descent velocity v. follow this path. Any particle with a rate of descent that is greater than this critical rate of descent is completely eliminated from the fluid, whereas those particles whose rate of descent is less than this value are only partially eliminated. The goal that

509828/077 1

Plate structure deodimentation device so ' that this critical rate of descent is as small as possible is used in the context of this invention as an optimization target. It can be shown that this design criterion the design criteria for the greatest possible elimination of suspended solids comes very close.

To determine the rate of descent, which corresponds to this critical actual speed, the Relationship between the x coordinate and the y coordinate of the sinking particle can be determined. Due to the definition of speed as a derivative of the The path over time results in:

dx / dt = ν

(8th)

509828/0771

This makes the following differential equation first Order, which describes the trajectories of the sinking particles:

dx ~ 2 /. ., "2 _2, ■ - .-. . -, cot α

(aL tan a) (R -a) cos α ^β sin α.

(10)

However, a particular particle trajectory is of interest, i.e. the trajectory that starts at χ = -D / 2 and y = 0 and at χ = D / 2 and y = L = L / cos α ends. Between integration these desired limits gives the following relationship for the critical rate of descent as Function of the design parameters of the system.

£ ₌ ^ tc ₌ T (D / r)

^v o [J- (VFr] [a / R) cos α - (L / R) sin_ ^ (L / R) tana + (D / R) cos c7]

(H) with

v. ~ critical rate of descent, i.e. the rate of descent of the particle that is critical Bahn follows.

This equation has been rearranged in such a way that the optimal ratio of descent rate to ascent rate should be found. In other words, this means that the optimal design of the sedimentation device is independent of the upward speed ν. Therefore, for a given container diameter the optimal sedimentation device without considering the flow or sinking properties

5038 28/07 71

the suspension to be clarified. These. Fluid properties or /. -Parameters only need to be used when deciding on the diameter of the sedimentation tank.

Consideration of equation (1.1) shows that the minimum determination of the critical sink rate ratio can be carried out in terms of three variables: the angle of inclination α of the plates that Height L of the sedimentation unit and the side length a of the rectangle inserted into the circular container. This function cannot be optimized in terms of the distance D between the plates, since it consists of both It is obvious from the equation itself as well as from physical considerations that the sedimentation the narrower the gap, the better. The optimal width D of the gap between the plates must can be determined from the properties of the inflowing suspension. It should be noted, however, that the relationships between the other three design parameters at the optimum not very much due to the distance between the Plates are affected: this will become clear later.

To get the parameters α, a, and L for the smallest value of £ To obtain, equation (11) is differentiated according to these parameters. Then the derivatives become zero set. These equations listed below are used for the optimal design of a rectangular sedimentation device, which is set in a circular container is used.

2 (a / R) - (a / R) (L / R) tan α - 4 = 0 (12)

(a / R) - (D / R) sin α cot α - 2 (L / R) tan α = 0 (13)

509828/0771

I- ■■ _. -. η

(L / R) (D / R) sin α - (a / R) (D / R) cos α - (L / R) ² see ² «

-cot α F (Vr) (VR) sin α + (L / R) (D / R) cos α

- (a / R) (L / R) + (L / R) ² tan α] * 0 (14)

In some cases it can be interesting to find an optimal one Design with regard to all three variables, whereas in other cases an optimum is desired can, in which one of the variables is fixed. For example it may be possible that the angle of the panels should be set so as to ensure is that the suspended solids slide off the plates, and then only after the optimum a and L is sought. For these two hypothetical Cases v / the above equations are used, although not all are used in every case.

The problem of determining optimal fourths for all three Variables can be given up pretty quickly, as there is no such thing as "such an optimum. When trying that Solving the above three equations simultaneously for the three design variables can be determined quickly that the solution is that the angle approaches zero degrees with respect to the perpendicular and the height of the plate structure goes towards infinity. One such a solution is obviously practically achievable * '

The realistic tasks, the best values for them. Parameters a and L at a given angle α and the best Values of a and α for a given length L of the device can be found easily using the equations (12) to (14) can be calculated. For a construction

> 509828/0771

with a predetermined angle α the equations (12) and (13) used and resolved for a and L at the same time. For a given height L of the device results solving equations (12) and (14) gives the optimal values of the design parameters.

Starting with the derivation of equations (1) and (2) above, the same procedure can be used for the others possible cases to be repeated. For the cylindrical container, the cases can be considered that the container is in an upright position and the flow is either upwards or downwards. or that the container is in a horizontal position, with the currents again upwards or downwards. The same four cases can be developed for a rectangular shaped container, as shown in FIGS. 6 and 7. The results of these derivations can be expressed in three equations are summarized which the three design formulas for correspond to the upward flow in a cylindrical vessel given by equations (12) to (14) are reproduced. The reference vector for these equations is in the vertical or horizontal direction according to the orientation of the container and in Direction of fluid flow. For each of the different cases there are some parameters of the equations changed. These general equations (15) to (17) are given below.

2 (a / R) ² - (a / R) (L / R) tan α -4 = 0 (15)

(a / R) - A (D / R) sin α f (a) - 2 (L / R) tan α = 0 (16)

509828/0771

C " -. -J- 2 2

L / R) (D / R) sin α - (a / R) (D / R) cos of- (L / r) sec α

- Af (α) {(a / R) (D / R) sin α + (L / R) (p / R) - cos α

- B [(a / R) (L / R) - (L / R) ² tan α]} = 0 (17)

with / + 1 for upward flow

A = \

1 for downward flow

f (a) = cota; B = +1 for vertical containers fCa) = tana; B = -1 for horizontal containers

[changeable for cylindrical containers

'R (1 for rectangular containers

For cylindrical vessels, equation (15) is always along with either equation (16) or equation (17) is used, depending on which of the parameters ά or L / R is given. If L / R is a given design value, then v / ground the equations

(15) and (17) are used to determine the angle α and the ratio a / R. For a given angle α Equations (15) and (16) are used. At a rectangular container just ground the equations

(16) and (17) are used, where a / R is set equal to 1. Equation (16) becomes' for a given angle α to Determination of the optimal fourth of the device length L / R or also L / a used. For a given value of L / a gives equation (17) the desired optimal angle α.

A typical example of using these equations for the design of sedimentation devices

5098 28/0771

by the following description of a preferred embodiment given the invention in which the container is rectangular.

A corresponding panel area 122 according to the invention was created of the mathematical analysis presented above, in which a plate formation container with a Length of 365.7 cm, a width of 182.8 cm and a depth of 487.6 cm is used, the plates 200 of the plate structure are 182.8 cm long and are arranged at an angle of 70 to the horizontal. The ι plates 200 have a distance D which is equal to 5.08 cm. These. Arrangement has proven to be very effective for the treatment of household wastewater, which was previously used with a coagulant and polyelectrolytes for flocculation numerous solids contained therein had been treated.

The plate structure according to the invention can have large dimensions have and does in the preferred embodiment. They are means of facilitating its manufacture and its installation provided so that it can be practically built and thus plate structures with such mass can be worn. The sheet structure according to the invention is thus made up of numerous plates that have been divided into sections and are connected by means of connecting elements in which the Plates are pressed in and preferably glued so that manufacture is largely facilitated. Furthermore, the plate structure preferably in a number of separate ones Sections are built which are placed side by side so that they work essentially as a whole.

509828/0771

As can best be seen from Fig. 11, there is Plate structure preferably made up of three sections which run in the longitudinal direction and are located next to one another. These sections are labeled 202, 204 and 206. The three sections are identical and in terms of their places interchangeable. Portions of sections 202 and 204 are shown in FIG. 12 and are discussed below described in detail.

The section 202 consists of numerous, elongated Corner elements 208, T-Elanenten 210 and cross elements 212, between which plate hexes 214 and spacers 216 are located. The corner elements 208 have an im essentially square cross-section and have grooves in two mutually perpendicular, longitudinally extending Provided surfaces, the grooves with the reference numerals 218 and 220 are designated. The T-elements have a rectangular shape and are provided with three grooves, namely two grooves in the longitudinal direction extending, .to each other parallel surfaces formed and indicated by the reference numerals 222 and 224, and a third groove 226 in the longitudinal direction Face that is perpendicular to the other two faces and runs between them. The cross elements 212 have a substantially square cross-section and are provided with four grooves 228, 230, 232 and 234, one in each of the longitudinally extending surfaces of the element. All Elements 208, 210 and 212 are long and are preferably the same or slightly greater in length than or as the plates 200, namely a length of approximately 195 cm. The corner elements 208 are spaced apart from the width of the section 202

509S28 / 0771

however, approximately half the width of the section, with the T-element 210A inserted in the middle of the section is to facilitate the installation of! middle spacers 216 to enable the section to be sufficiently stiff ' is to be handled easily. The spacers 216 have a width that is approximately the same is the distance D, although this can be modified somewhat in order to ensure the presence of T-elements, Balance cross elements and side elements. the Disk units 214 are inserted into grooves 218 and 222, preferably after a suitable one Binder has been applied so that a solid and rigid construction between the corner element 208 and the T-member 210 and the plate unit 214 is formed. Similarly is on the right Side of the T-element 210A is the right plate unit glued into the groove 224 and into a groove in the corner element 208B on the right side of the end face of the section. The remaining construction will be apparent to those skilled in the art upon consideration of FIG. 12, so that accordingly a grid structure can be built that is approximately two panel units 214 wide and is as long as the number of plates inserted into the plate structure, this being replaced by the ones previously reproduced Design parameters is determined. Each of the Sections 204 and 206 are constructed identically to section 202. Thereafter, the sections 202, 204 and can be placed in the plate formation container 122, and they can be supported by any underlying support structure, for example by several angle iron girders that lie under the sections and hold them at the desired depth. These

509828/0771

Angle irons are 'shown in Figures 9 and 10, where they are designated with the reference numeral 236.

After the sections have been put in place, can, as shown in Fig. 10, a pair of transverse angle irons 238 and 240 above the Sections are screwed on so that they are held securely. From the foremost plate 200A in Fig. A plate 244 is preferably arranged up to the wall 242 of the container, which is intended to prevent liquid from flowing falls into room 246, so that a slow deposition of particles in this room is prevented, that would require periodic cleaning. However, if the periodic cleaning is not a chore is held, the plate 244 can be dispensed with.

One of the major difficulties in design, construction and when using plate structures is to ensure that the flow between each pair b'nachtbarten plates essentially the same as is the flow between every other pair of plates. The reason for this is that when the flow is uneven, that exiting at the top of the plates Particle distribution will be different, resulting in an uneven and undesirable separation of the particles for the entire plate structure. This means that when the mean flow passes through the Plate structure or the total flow through the plate formed as desired, but the flow between certain plates is too high, in the liquid, that flows through the pair of plates at high speed, entrained particles too large for the design of the plate

5098 23/0771

what emerges from what has already been reproduced will be educated Analysis results. The numbers carried will also be too great. To fix this are here Means for comparing the flow through the entire plate structure provided, and the preferred Means are shown in Figures 8, 9 and 10. As shown in these figures, are in the preferred form of the device for eliminating uneven flow provided several gutters, from three of which are shown here and labeled 250, 252 and 254 and which extend over the length of the plate structure 122 extend and which are connected at x 256 so that an outflow for the outflowing flow through the outlet tube 124 is made. The number of troughs does not form part of the invention and can be any Number, starting at one, may be provided. However, it is preferable to use a reasonable number of more taken as one, for example three, as the velocity of the liquid overflowing into the gutters the slower and the greater the excretion of undesirable particles from the liquid, the more gutters are provided. The gutters are shown positioned above the upper ends of the panels 200 and are preferably located appreciably above the upper ends of these plates, namely in the On the order of at least about 178 mm. In the preferred embodiment of the invention described herein is and in which the plate structure and the Size of the construction as previously described in detail, it has been shown that the upper edges 258 the Rinnan preferably about 305 mm above the upper ends of the plates 200 are (see Fig. 13). The diameter of the grooves can be of the order of

509828/0771

about 152 rom for a plate with this one described size. However, the diameter is not critical and is more like one Question of adequacy in terms of establishing and directing the flow of fluid that this creates should flow. . "*

With this arrangement of the channels 250, 252 and 254, the liquid, which flows up through the plate structure between the plates 200 'and thereby separates particulate matter, exits at the upper ends of the plates 20.0, where it meets a noticeable column of clarified liquid, as already described. was. This significant column or High clarified liquid serves to equalize the pressure over the entire surface of the board set <thus characterized the flow of liquid zwisehen each of the pairs of plates is equalized. Maintaining this water column at the desired value results in connection with a very low overflow rate of the clarified. Liquid flowing into the runners, an outflowing liquid of extremely high quality with very few entrained particles, these being of very small particle size. The clarified liquid makes its way up from the tops of the plates 200 and - if; required - sideways until it hits one of the top edges 258 of a trough, after which the liquid runs over the top edge and into the trough to be slowly transported to the outlet tube 124. The upper edges 258 can be adjusted very carefully with regard to their height / so that a very long weir is obtained / so that the speed of the

509820/0771

_ 44 -

Liquid flowing into the weir is kept low. At as low a speed of running over the weir any liquid entrained particle will not be significant with a diameter able to adhere to the _A surface of the liquid. If the height of the liquid is carefully adjusted so that it is very little above the top edges 258 of the troughs, these larger particles will not move over the top edges 258 but hit the sides of the troughs 250, 252 and 254 and then fall down, possibly through the panels to the floor of the panel assembly. Although not required, the top edges 258 of the troughs can be sawtooth in order to take advantage of the well known useful property of a sawtooth weto which enables the manufacturer to precisely set the weir at the desired level relative to the water level. This is a known tool and does not in itself form part of the invention.

Other devices for equalizing the flow of liquid through the plate structure can alternatively or in addition to the high column described above can be applied from clarified liquid. As FIGS. 9 and 10 show, a sieve grille 260 is provided for this purpose arranged above the upper ends of the plates 200 and preferably rests on them, this sieve grid has such a mesh size that it has the largest particles that theoretically pass through the plate structure it is possible to flow through the spaces in the sieve grille without hindrance. Consequently the sieve grid does not act as a sieve to prevent particulate matter from passing through it

S09828 / 0771

should prevent. The purpose of the sieve grille is to serve as a large-area "throttle" that regulates the flow of the Fluid, which may flow faster than desired, is reduced, thus a low one Increasing the flow of liquid is effected, which flows at a speed that is lower than the speed determined for the plate structure, so that an essentially equal fömge flow is achieved. The mesh size of the grid is preferably not significantly larger than the one that is required to allow the passage of particulate matter, since the throttling effect is around the more uniform it will be, and consequently the more uniform the flow through the sieve screen will be, ever! yours is the mesh of the sieve "

As FIGS. 14 and 15 show, other devices be provided to further reduce the content of particulate material between the Plates 200 of the plate structure 122 has passed. If the gutters 250, 252 and 254 are not provided are, for example, a plurality of transverse grooves 261, 262, 263 and 264 can be provided The term “transversely” here means transversely to the direction of flow of the liquid above the plates 200 target. When the liquid in the plate structure 122 according to Figures 14 and 15, the upper ends of the Leaves plates and flows to the weir 266, it is forced to over the channels 261, 262, 263 and 264 to flow, each in their vicinity block the vertically flowing liquid between the upper Ends of the plates. Thus the troughs create eddies in which "there is no upward velocity component." in the flowing liquid. Without

8AD ORIGINAL ORIGINAL INSPECTED

509828/0771

Upward components in the horizontally flowing liquid, moving over the top of the plateau to VZehr 266 there is no sufficient upward directed force that could keep the solids entrained in the liquid so that the Solids precipitate in the transverse "channels so that the liquid that has flowed through the plate structure is further clarified. Thus becomes the particle content of the liquid leaving the plate structure by flowing over the weir continues reduced.

Although the use of the channels 261, 262, 263 and 264 described here, as shown in FIGS. 14 and 15 is done in combination with the sieve grate 260, it goes without saying that the grooves 261, 262, 263 and 264 can be used without direct cooperation with the sieve grid and that of course the mesh screen 260 can be used without using the gutters at the same time. if If the troughs are used with or without the screen mesh 260, considerable amounts will accumulate in them Particulate material, as the plate structure is used. The gutters can either be cleaned by making them easily removable so that they are periodically lifted out of the plate structure and washed to remove the particles, or they can be hydraulically cleaned, by providing numerous nozzles at one end of each of the troughs which rinsing the troughs while they stay in their position.

If so desired, the combination of the

509828/0771

. -47-

Gutters and sieve grids are further improved with regard to a flow that is as uniform as possible everywhere that a second sieve grid 268 is provided above .on the channels 262, 264 and 266, wherein then the gutters not only function as described above meet, but also as a spacer between the serve both sieve grids. Alternatively, the two Sieve grids together with ordinary spacers 269 can be used, which keep the sieve grids at a small distance, this distance being an additional Increasing the uniformity of the flow throughout Plate structure allows (see Figures 9 and 10). That Plate structure is built in the manner described above, ■ by the load-bearing elements, namely corner elements 208, the T elements 210 and the cross elements 212 with the intermediate plate units 212 and spacers 216 are joined together so that a section of the Plate structure is formed, 'the sections with denoted by reference numerals 202, 204 and 206. The sections of the plate structure are then next to each other arranged in the container 122 and preferably secured or fastened in this position by means of angles 238 and 240. A cover plate 244 may be provided extending from the top of the foremost plate 200A of the Plate to the wall 242 of the plate container extends. If the channel-like weirs 250, 252, and 254 are used, then it is preferred first, the middle weir 252 is positioned between the front and rear walls of the plate structure container and leveled in height to ensure that it is the correct altitude above the tops of the Has plates of the plate structure. Then the side gutters 250 and 254 are inserted, with their rear ends attached to the rear wall of the plate structure

509828/0771

den and their front ends are connected to the middle gutter 252- In this lacje the gutters 250 and 254 also aligned in height and brought into a plane with the weir channel 252. The level at which the upper edges of the weir channels are set, can be chosen, v / obei the designer 'at the Determination of this place must take into account that it it is desirable to have a substantial hydraulic head or column of liquid above the plates of the plate structure to have, and also .the flow rate for which the plate structure is designed, must be observed. After this this construction has been completed, the plate structure is ready for use. After the plate structure with the structure according to the. Figures 7 and 8 have been completed and installed in the manner described above is, in the alternative embodiment according to Figures 14 and 15, the sieve grille 260 over the upper The ends of the plates are placed v / earth, after which the plate structure is then ready for use. When the transverse Gutters 261 to 264 are used, they can be arranged in the plate structure container, with the Undersides of the gutters are relatively close to the upper ends of the plates of the plate structure. the transverse gutters can be attached to the side walls of the panel if so desired. If the second screen mesh 268 is to be used, it would of course be over the tops of the transverse channels. The use of the plate structure is the same as for all before known plate structures. Basically, the liquid in the plate formation container is below the plates fed and can then flow up between the plates and from there over the weirs to the outside, namely

BATH 509828/0771

.Either via a straight weir as in Figure 14 and 15 or over the channel-like, in the longitudinal direction extending weirs of FIGS. 8, 9 and 10. From there the liquid can flow to the outlet 124.

Although the sieve grids described here are shown as stationary, it is obvious that these Sieve grids should be removable so that they can be cleaned regularly. Thus, the sieve grids be arranged in frames which are detachably mounted in the manner shown. An alternative to expandable, fixed sieve grids would consist in the fact that the sieve grids are movable, thereby the plate structure periodically fresh screen mesh sections fed while the rest of the Working position of the sieve grid is removed. This can be achieved by placing the screen grids on rollers are mounted, with a roller as the feed roller and the other serves as a take-up roller and the rollers-on opposite sides of the plate structure are arranged. For continuous or periodic shifting the screen grid for the take-up roller can be operated by hand, semi-automatic or automatic devices can be provided, thereby to the top of the plate structure new, clean sieve screen sections are routed / grounded.

Yet another alternative to reduce the Soiling the sieve grille consists in the sieve grids to be mounted in connection with a swing mechanism so that the sieve grille is close to a At the end of the plate structure, usually the top, a vibrating movement or to and fro movement is impressed will. The movement of the sieve grid is impaired

50 9 8 28/0771 BAD

not a droll effect. The movement will however
reduce the likelihood of the mesh screen becoming dirty.

The following is the ozonization sonication chamber described. _.

The ozonization sonication chamber according to the invention is shown in detail in FIGS. 16, 17, 18 and 19. As already mentioned, the zonization chamber 28 can have any desired construction without deviating from the invention with regard to the overall system. Present is
however, the ozonization sonication chamber shown in FIGS. 16 to 19 in the frame is preferred
to use the system because it has proven to be extremely effective in oxidising and sterilizing wastewater.

The ozonization sonication chamber 28 is preferably formed from a long, cylindrical tower 300 which has a top 302 with an therein
Opening 304 has, the bottom of the tower 300 stands on a suitable base chamber 306 which extends the bottom of the
Tower seals and forms a space for devices yet to be described. The top opening 304 serves as an outlet for withdrawing foam that may be generated as a result of ozonization and sonication of the treated wastewater. In the wall of the tower 300 an inlet opening 308 for the inlet from the filters 26 is provided. The container is also close with an outlet port 310
the bottom thereof, with the outlet opening leading to the ozone contact chamber 308 when required.

509828/0771

Otherwise he can go directly to the linger basin 32 or lead to the final exhaustion of the system. The tower can be used for ease of manufacture and maintenance 300 can be constructed from two main sections 312 and 314, which are connected by means of a flange connection 317 are. This is optional; however it will preferred. Section 312 is essentially one Line that serves to the inlet that passes through the inlet opening 308 enters to flow down through the tower - as will be shown, however, is that liquid flowing through / section 312 is exposed to both shark energy and ozone at the Purpose of a pre-treatment before the liquid enters the zone of maximum ozonization and sonication Close to the ozone injectors and ultrasonic transducers, which will be described later. , To facilitate the manufacture and the maintenance section 314 is off three separate subsections 316, 318 and 320 are built to allow the installation of the converters and ozonators in section 314 is simpler, as will be explained. ,

It has been found that the best results are obtained using ozone and ultrasonic vibrations be when the treated liquid on the ultrasonic vibrations meets before or at the same time as the ozone and not after it has been ozonated. Thus it will be seen that the transducers and ozonators described below are arranged to be used for ensure this sequence of events.

The ozonization sonication tower 28 are special two sets of ultrasonic transducers used that come with

6098 28/07 71

denoted by reference numerals 322 and 390. The ultrasonic transducers 322 preferably have a relatively low frequency, for example of about 20 IcHz, which is just in the ultrasonic range. Preferably four transducers 322 are provided which are magnetostriction transducers. As best seen in Figure 18, transducers 322 on four exposed surfaces 324 are one rhorriboid-shaped holding frame 326 mounted ,, being the surfaces formed by the outsides of four plates 328 that form the framework. The plates are at their upper and lower ends with the help of U-profiles 330 connected. The 'rhornboid' frame 326 is mounted within the wall of the tower 300 and with this between the sections 316 and 318 with Connected by means of a retaining plate 332, which is connected between flanges 334 and 336 at the bottom of the section 316 and is held at the upper end of section 318. The flanges are by means of not shown, suitable Bolt connected. The holding plate 33 2 is shown in F.ig. recognizable and has a substantially circular shape Scope and is with numerous bolt holes 335 as well provided a central opening of considerable size, which is designated by the reference numeral 337. The opening 337 is preferably shaped to have two parallel edges 338 and 340 that are straight, and has a pair of curved end edges 342 and 344 concentric with the outer edge of the plate, the curved ends extend between the ends of the side edges 338 and 340. At the side edges 338 and 340 a pair of retaining plates 346 and 348 are welded on, the retaining plates running vertically and essentially

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The same way as the egg holder frame 326 are shaped. The support frame is preferably welded to plates 346 and 348. The transducers 322 are on the four surfaces 324 of the holding frame with the help of any goeineter means, -for example with the help of not bolt shown, mounted. The transducers and the opening 337 have together with the actual holding frame dimensions such that around the transducers and through opening 337 there is a large passage for the there is liquid flowing downwards so that it can flow through it without any significant hindrance. Of the The purpose of inclined mounting of the transducers 322 is is to avoid reflecting sound energy from the wall of the tower back to the transducers 322 as such a reflection could potentially damage or destroy the transducers.

Power must be supplied to each of the transducers. Therefore each of the transducers is provided with a conduit 350 which extends from an inlet opening 352 in the wall of the Tower leads to an opening 354 in the converter itself. Conductors from an ultrasonic generator pass through line 350 outside the tower to the input terminals of the converter 322. As already mentioned, the ultrasonic generator for the transducers preferably operates at a frequency of approximately 20 kHz.

As has also already been mentioned, is the ozonization sound tower 28 designed so that the sonication takes place before or at the same time as the ozonization. As as will become clearer below, there are two here separate locations for the delivery of ultrasonic energy provided, which takes place on the one hand, by means of the converter 322 and, on the other hand, by means of the converter 390,

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which will be described later. Below the converter 322 there is an ozonator 356, which can be operated by any can be of suitable design. At present, however, preference is given to the known type of porous stone, the is also shown. The ozonator 356 is built from a diametrically extending tube made of porous stone, which is denoted by the reference numeral 358. The inlet for tube 358 is identified by the numeral 360 denotes and is in the form of a nipple extending from the inlet end of the porous stone tube 358 to a Mounting flange 36 2 runs. There is a second on the outside of the mounting flange 362 Nipple 364 which leads to a suitable fitting leads, which here has the form of a flange 366 and connected to a suitable ozone supply line 368 can be (see Fig. 16). The ozone generator is not shown and can be entirely conventional. For reasons of mechanical rigidity, the end of the tube 358 opposite the inlet end can also be used a support rod or a support tube 270 may be provided, which is attached to a suitable mounting flange is mounted, which is arranged diametrically opposite the mounting flange 362, which the aforementioned ozone supply line holds.

It should be noted that the invention does not apply to the use of a single, porous stone ozonator, as previously described, is limited. If so desired, numerous such, porous Stone ozonators are used, which can be arranged in any desired pattern, or others Types of ozonators can be used without departing from the scope of the invention.

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Below the Osonatbrs 356 there is one with a perforated plate 374, which largely separates the section of T.urwes 2S from the rest of Turin. These Plate 374 is between F3 flanges 376 and 378 at the bottom of section 318 and at the top of the section, respectively 320 inserted. It is held there by means of suitable screws, not shown. The plate 374 has a relatively small, central opening on the order of about 10.1 cm, through which a small knee tube 379, also 10.1 cm in diameter which allows that through the upper portion of the pzonization sound tower after below flowing liquid flows out through the bottom of section 318 into section 320, wherein the liquid is directed away from the outlet opening 310, so that a significant residence time of the Liquid is ensured in the lowest section 320 of the tower. At the bottom of section 320 is a second ozonator 380 is placed in all respects may be identical to ozonator 356 and preferably is - and is mounted in essentially the same way. If so desired, several Ozonators should be provided at this height. A membrane 382 is arranged immediately below the ozonator 380, which forms the bottom of the Ozonisatior.s sound tower and the upper end of its base chamber 306 and those mechanically from flanges 384 and 386 at the bottom of section 320 and the top of the base chamber, respectively 306 is held, these 'flanges by means of suitable fastening elements, for example by means of not shown Screws, fastened together. Within the hollow cover chamber 306 are numerous ultra-

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sound converter with a relatively high frequency like this arranged so that their radiating surfaces bear against the membrane 382 or are mechanically coupled to it. These ultrasonic converters are preferably, but not necessarily, piezoelectric converters which are set in this way are that they give an output oscillation on the order of 85 kHz or more. This converter 390 are arranged inside the base chamber and without contact with the flowing liquid, which is extremely would have a detrimental effect on their effectiveness and the results achieved thereby. Because the ozonator 380 is very is arranged close to the vibrating membrane 382, it is found, however, that the through the knee tube and then liquid flowing out of outlet 381 undergoes simultaneous ozonization and sonication with high Frequency is suspended.

The ozonization tower described above has a number of desirable properties. The most prominent of these is that the entire tower is after the countercurrent principle works, thus the effect the ozonization and sonication to which the liquid is exposed is significantly increased. This means that the fluid, as it moves from the inlet to the outlet, is constantly exposed to higher and higher concentrations of ozone and the ultrasonic radiation, especially those with a lower frequency, and this is constantly increasing The density of the ozone and the sound energy has a steadily increasing influence on the oxidation and sterility the liquid flowing through the tower. Second, it can be seen that the tower 28 is two separate stages of the Uses ozonization and sonication and that the sonication with two different sound frequencies

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to be led. The reason for using different sound frequencies in the two sections is to -that it has been established that certain substances are more sensitive to one frequency than to another and that by using different frequencies a larger range of substances can be effectively used with sound energy and can also be made more sensitive to treatment with ozone.

For a plant for 2,271,264 liters per day, like them As described herein, the inner diameter of the tower 28 is approximately two inches and the overall height of the tower including the 25.4 cm base chamber is approximately 609.6 cm. The residence time of the liquid in the Tower is about two and a half minutes. The power consumed by transducers 322 is approximately 4,000 W, i.e. approximately 1,000 W per transducer 322. The power consumed by transducers 390 is approximately 4,800 W, i.e. approx. 200 W per converter, since the system described has an arrangement of 24 such High-frequency converters located in the base chamber 306. It is important that the converters have such performances be operated that cavitation is generated in the liquid flowing through the tower for treatment.

I '; The amount of ozone to be used in tower 28 depends largely on the nature of the inflow to the tower and the government regulations regarding the Downstream for the cleaning system. In the case of an influx of ordinary household waste that was before the Feeding into the tower 28 has been treated in the manner previously described, it has been found, however, that when ozone is fed in in such a large amount,

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that the amount of the total through the tubes 356 and 380 ozone introduced into the container in the range between one and ten parts per million parts treated wastewater lies, a desirable result is achieved. Exceptionally good results were achieved in pretreated household wastewater when approximately two parts per million ozone was in the chamber be introduced, preferably one part per million in each of the two ozone injection stations. Generally However, this means that when such small amounts of ozone are introduced into the ozonization sonication chamber 28 v / ground, an ozone contact chamber will likely be required as - generally speaking - established became that about six to fifteen parts per million were required to ozonize the entire system in order to achieve the required degree of oxidation and sterility. If, however, higher ozone concentrations in the ozonization sonication chamber 28, then less or no ozone is in a contact chamber is required, eliminating the need for such a contact chamber. As alternative For the use of ozone contact chambers, additional ozonization sonication towers 28 can be installed in series can be used with the chamber 28 described above, so that the additional advantage of a sonication before the ozonization is obtained, v / as described above.

While here preferred embodiments of the invention While changes and modifications have been suggested, changes and modifications are other possible within the scope of the following claims without the basic idea and scope of the invention to leave.

r * patent claims:

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Claims (15)

Claims 1) Process for the purification of wastewater with raitführung Solids and dissolved impurities, characterized in that the waste water contains a coagulating agent it is added that a polyelectrolyte is added to the waste water to form a flaky precipitate is that the wastewater then through a plate structure Is led to a sizeable proportion of any to remove solids suspended therein, and 'that the wastewater then ozone and sound energy with one Starch is exposed to the generation of cavitation in the wastewater is sufficient, the wastewater not being exposed to cavitation later than at the time which it encounters an effective concentration of ozone. 2. The method according to claim 1, characterized in that the wastewater sound energy at two different frequencies is exposed, each of these sound energies causing cavitation in the wastewater. 3. The method according to claim 2, characterized in that one of these frequencies is in the ultrasonic range, but ■ not above 30 kHz "and that the other frequency is at least twice as high as the one frequency. 4. The method according to any one of claims 1 to 3, characterized marked that the sewage and. the ozone in opposite Directions flow. 5. The method according to any one of claims 1 to 4, characterized characterized that the wastewater while there is ozone and 50-9828 / 0771 * Schallenerige is exposed, flowing down a column and that the ozone is close to the bottom of the Pillar is introduced. 6. Verf äi ren according to one of claims 1 to 5, -thereby characterized in that the co-regulating agent ferric chloride and that the polyelectrolyte is an anionic polyelectrolyte is high molecular weight. 7. The method according to claim 6, characterized in that the amount of ferric chloride supplied between approximately 30 and 70 milligrams per liter of wastewater and that the amount of polyelectrolyte supplied is approximately 0.5 milligrams per liter of wastewater. 8. The method according to any one of claims 1 to 7, characterized characterized in that, after the polyelectrolyte has been added to the wastewater, it is transferred to a clarification or leaching basin is given and that the wastewater in this basin a circular flow with a speed of approximately 3 rpm impressed v / ird. 9. The method according to any one of claims 1 to 8, characterized in that ■ that the wastewater is treated with ozone is, while, no sound energy is available after the treatment .'des wastewater with ozone and sound energy has been completed. 10. Plant for the purification of wastewater, characterized by an equalizing tank (16), a settling tank (18), a Weir (62) in the settling basin, a device (56, 60) for transferring waste water from the equalization basin to the Weir, a device for adding a coagulant BATH ORIGINAL 509828/0771 in the sedimentation basin / flocculation basin (20), an underwater weir (88) between the sedimentation basin and the flocculation basin and a flow of wastewater from the settling basin into the flocculation basin, a device (82 ') for adding Polyelectrolyte in the sewage near the underwater weir, a device (106, 108, 110) for slowly stirring the wastewater in the flocculation basin, a clarifier (22), a double underwater weir (112) that creates a current the wastewater from the flocculation basin to the clarifier allows, wherein the clarifier has an outlet (124), a 'plate structure (122) in the clarifier between the second underwater weir and the outlet and to remove suspended solids from the wastewater, a vertical ozonization sonication tower (28) with an inlet. (308) near its upper end and an outlet (310, 381) near its bottom, means (132) for transferring waste water from the outlet (124) of the clarifier to the inlet (308) of the tower, a device (356, 380) for feeding ozone into the tower, a device (322, 324) for applying sound energy on the tower, which is below the inlet of the tower and above the device for feeding in ozone is arranged in the tower and can apply sound energy of such strength that it is used to generate Cavitation in the wastewater within the tower is sufficient. 11. Ozonization sound tower, characterized by a perpendicular outer side wall defining a perpendicular space and an inlet opening (308) for. ^ Sewage near the top and an outlet opening (310) for sewage near the bottom - .SAD ORIGINAL 509828/0771 has a device (356) for feeding ozone into the tower and a device (322, 324) for Auf ™ • Bringing sound energy to the tower, below the inlet of the tower and above the facility is arranged to feed ozone into the tower and apply sound energy of such strength can that this is sufficient to generate cavitation in the wastewater within .des tower. 12. Ozonization sound tower according to claim 11, characterized by a second device (380) for feeding ozone into the tower and a second device (382, 390) to apply sound energy to the tower with such strength that it is used to. generation of cavitation is sufficient, these second devices both being below the former Device (356) for feeding in ozone, and are located close together. - 13. Ozonization sound reinforcement tower according to claim 12, characterized in that the two devices for introducing sound energy into the tower comprise ultrasonic transducers (322, 390) and that one of the devices (382, 390) operates at a frequency which is at least twice as high as ^! the other is. 14. Ozonization sound tower according to claim 13, characterized in that the upper device for feeding in ultrasonic energy comprises an ultrasonic transducer (322) which operates at the lower of the two frequencies and is oriented at an angle to the wall of the tower, so that Scarf! Energy coming from the wall 509828/0771 is essentially not reflected on the Converter meets. 15. Ozonisat-ion-G-B.GSchailungs-TuxJTi according to one of the / claims 12 to 14, characterized by one with an opening provided plate (374), which the room in -two acoustically isolated sections-divided, one of which is the first device (356) for feeding Contains ozone and the first device (322, 324) for applying sound energy and the other, Acoustically insulated section the second device (380) for feeding in ozone and the second device (382, 390) for applying sound energy. ORIGINAL 509828/07 7 1 Blank page