FI89703C - Device for the treatment of liquids, especially waste water - Google Patents

Description

89703

Apparatus for treating liquids, especially sewage

Anordning för behandling av vätskor, speciellt avfallsvatten 5

The invention relates to a device for treating a liquid, in particular waste water, comprising a body consisting of a cylindrical part and a conical lower part, a mixing part and a clarifying part, which device includes sludge recycling, possible foam separation, a supply pipe, a la-10 separator and a flow inducer.

Wastewater treatment is an increasingly important measure as society becomes more technical. As technology progresses, wastewater emissions increase. As living standards rise, water consumption also increases. The average city-dweller-15 per person is calculated to receive more than 150 liters of wastewater per day. In large cities, high-culture countries calculate wastewater production as much as 250 l per day. Industry itself can be a major consumer of water, i.e. there will be a lot of wastewater. They can contain fats, organic emissions, phosphorus, nitrogen and metal compounds, etc. Essential to many of these emissions is their biologically oxygen-consuming property, i.e. they reduce the amount of dissolved oxygen in the water, thereby disturbing the ecosystem in the water body. Thus, the most important tasks in wastewater treatment are to eliminate organic components that cause biological oxygen demand from the water.

25 • Several such methods are known. Oxidation methods to direct air into water have long been developed. Efforts have been made to provide efficient oxygen-dissolving solutions and devices. Unfortunately, the weakness of many solutions is the high energy consumption of dissolved oxygen:. Compared to 30.

In a biological treatment plant, it is essential not only to get oxygen into the water ...: but also to get the activated sludge as evenly as possible to the entire amount of water, i.e.

to make the bacterial activity as even as possible throughout the amount of water-35, i.e. the sludge and oxygen content of the water as even as possible. Such a solution has been sought in biological treatment plants by directing the pressurized air from the bottom of the water basin along the entire path of the basin by means of fine nozzles or diffusers, trying to keep the air bubbles as small as possible. After all, the dissolution of a gas in a liquid is directly proportional to the contact area and the pressure of the gas. The deeper the water can be supplied to the water, the better the oxygen supply with the same bubble size. So aim to get as many 5 small air bubbles as possible and get them as deep into the water as possible, while trying to get as even a flat space in the water space as possible with your circulation and suspensions. In this case, the bacterial pollination is good, whereby the solids content, especially the organic waste, decomposes, the phosphorus is oxidized to insoluble and the effluent water contains oxygen.

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With regard to the state of the art, reference is made to FI applications 121/70 and 752256.

FI application 121/70 discloses a water treatment plant which includes an aeration department to which the water to be treated can be led and clarification -15 a department from which the water from the aeration department can be removed after treatment. The clarification tank is provided with an aeration section connected to it at its lower end, with devices for supplying gas and circulating the water to be purified with the sludge continuously in the aeration section. The aeration compartment is formed by two nested pipes 20 which communicate with each other at their lower and upper ends so that water in the aeration compartment can circulate down one pipe and up along the other pipe.

FI application 752256 discloses a device for wastewater treatment, 25 which has oxidation, flotation and post-clarification zones. Oxygen or an oxygen-containing gas is introduced into the liquid from which the gases dissolved therein have been separated by applying pressure shocks to the liquid and / or subjecting the liquid to an oscillating motion, after which the desired gas, e.g. oxygen, is added to the liquid. The main stream of liquid 30 to be cleaned from the oxidation zone is recycled to the flotation zone, from which the gas dissolved therein is removed and to which oxygen gas or air is added.

Solid particles remain in the treated water, which should be extracted from the water before it is discharged or discharged into public waters. For this purpose, oh in the rear end of the wastewater treatment plant the so-called. clarification section, 89703 3 with possible suitable flocculants, i.e. using precipitators, the precipitate is settled to the bottom of the clarification unit, from which the precipitate is then removed, thickened and possibly dried using suitable pumps or removers. The size of such water treatment plants 5 grows quite large. It is clear that the amounts of water they treat are also large. After all, the capacity of the clarification basin is calculated roughly according to the area of the clarification basin, so that one (1) square meter (m2) in the clarity basin corresponds to an hourly capacity of about one (1) cubic meter (m3) of water. In small units, the purchase price becomes considerable if equivalent treatment of the pool is desired. There are no similar functions for such situations yet.

It is this drawback that is to be solved by the present invention.

In order to achieve the above and later objects, the device according to the invention is mainly characterized in that the mixing part of the treatment device consists of a cylindrical inner cell and a conical lower part with a discharge connection, the mixing part being arranged so that a ring gap between the body and the mixing part a treatment tube is arranged, in which a flow inducer is arranged and above which a supply tube is located, that the clarifying part of the treatment device is formed of a conical part surrounding the inner cell and lamella cones, a clean liquid outlet 25 outside the conical part and a foam and floating foam above it form; . from the bed that the treatment device is provided with a sludge recirculation piping outside the body, which starts from the sludge removal connection at the conical bottom of the treatment device and branches into a sludge discharge pipe and a pipe leading to the supply pipe.

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The essential functions of the invention are all in the same device: the supply of air to the water as finely divided as possible and the care of homogenizing the water under treatment, suspending it in the primary circuit and recovering from the secondary circuit the necessary so-called the desired amount 35 back to the primary circuit and directing the amount of water corresponding to the supply out of the device via lam clarification. In addition, the device according to the invention provides for the separation of oil and fats from water and the removal of possibly floating components from the treatment device in excess of e.g. as foam through a separate outlet. The size of the apparatus is small compared to its power and its clarification capacity is large in relation to the floor surface required by the apparatus 5.

An apparatus according to the invention will be described with reference to the accompanying Figure 1, which in no way limits the invention to this embodiment alone.

10 The wastewater treatment cell is formed by an outer jacket 1 and a conical part 1a. Inside these there is an almost similar-looking inner cell 2 and a corresponding conical part 2a. Between these conical parts 1a and 2a there is an annular gap in which a slurry flow k passes to the outlet-15 8 at the lower end of the conical part 1a. Inside the inner cell 2 there is a concentric treatment tube 3, the upper edge of which is close to the upper edge of the inner cell 2. Both upper edges are lower than the liquid surface in the cells, the VH20 surface, which is more than the distance ΔΚ between the upper edge of the treatment tube 3 and the lower edge of the concentric supply tube 16. This interval ΔΚ is determined in such a way that the liquid flow sucked by the impeller 17 in the treatment pipe 3 in the ring opening ΔΚ is set within reasonable limits known per se, so that unnecessary pressure losses do not occur. In this embodiment, the lower end of the supply pipe also extends below the surface of the liquid surface VH20. The upper edge of the inner cell 2 is above the lower end of the conical hopper 6a. The cleaning cell 25 is supplied with a flow a through the lid of the cell 1 to the supply pipe 16. The flow a is substantially smaller than the liquid flow taken by the impeller 17, so the flow a is sucked into the impeller 17 together with the flow d through the ring opening ΔΚ. The impeller 17 is supported by a hollow shaft and a belt drive 12 and bearings 13 so that the rotational movement causes a cavitation-like suction due to the setting angles of the impeller blades 17 so that air is absorbed along the hollow shaft into the impeller 17. into water into very fine bubbles which burst in flow c away from the lower end of the hand-tube 3. The amount of air absorbed through the shaft into the impeller 17 can be adjusted by the regulator 14. The flow c mainly turns into an upward primary flow 89703 5 between the pipe part 3 and the inner cell 2 '. Only a small and heaviest part of the flow c (sand, gravel or heavy sediment) is distributed downwards as a flow 1 through the opening 7 in the funnel part 2a. The flow 1 coincides with the flow k and together in this embodiment they suck from the housing 8 through the pump 9 into the flow in the sludge recirculation line II to the divider 10, from which part of the flow is directed out to flow h. The rest of the flow in sludge recirculation with a. The major part of the flow c circulates in the mixing section I. The flow through the mixing section I discharges an amount of liquid corresponding to the feed a and the flow h as a liquid stream e depressing down the ring opening between the components and precipitate. The rest of the flow e turns 15 through the intermediate spaces of the lamella cones 6b, 6c, 6d, etc. into an outlet 5 with openings in the cell wall 1 and below and outside the openings a gutter 4 with an outlet 4a the difference between flows a and h. The outer edges of the lamella cones 6b ... 6d, etc. leave a flow-20 between the wall of the cell 1 to allow the liquid to flow to the outlet 5. A slurry settles in the lamella cones 6b ... 6d etc., i.e. the lamella cones operate in the so-called

• as a lamellar clarifier. The settled precipitate continues to drain and sinks. as background k. Thus, the outflowing liquid flow f is clarified and free of solids.

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The mixing section I contains air in the flow c, in which case it tends upwards and carries with it any oils and fats as well as a part of the slurry at least light and floating solids which rise to the liquid surface. In this presentation, the thickness ΔΗ of this layer is chosen as the limit by which the height.:. When ΔΗ is exceeded, the flow g begins to remove the foam. Thus, the cell is obtained as separate outlets: oil and floating solids as flow g, • heavy precipitate and solids as flow h, and purified water / liquid: as flow f.

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The upper conical part 6a of the conical lamella part extends to the outer edge of the cell 1 and thus the foam cannot mix with the outgoing liquid stream.

With the solution according to the invention, possibly with a biological wastewater treatment cell 5, it is possible to clean e.g. wastewater, whereby with a suitable bacterial strain it is possible to remove the organic finishing agent by circulating the water under sufficiently oxidizing conditions and for a sufficient time, the mixing section I handles the internal circulation and the sludge recirculation line II returns the desired part 10 to the treatment. As a result, even moderately high solids concentrations can be reached at sludge concentrations. The capacity of the conical lamella clarifier included in the devices can be easily obtained due to the structure of the device. The conical lamellar clarifier differs in advantage from the conventional lamellar clarifier in that the flow rate of the liquid flowing through it decreases with the square of the diameter increase. In a standard lamella clarifier, the flow rate remains constant throughout the landing cell.

The invention achieves considerable cost savings compared to solutions which require the construction of conventional wastewater treatment plants. In the future, it will also be necessary to treat even small amounts of wastewater. In such solutions, even more difficult wastewater problems can be easily implemented with the cell according to the invention.

The solution according to the invention presented is not merely an embodiment shown. The same embodiment of the primary and secondary flow sections is possible with several placements. The solution can be varied, e.g. In this case, any sand, gravel or heavy sediment 30 does not unnecessarily consume the pump 9 and the impeller / flow agent 17, since there are other types of flow agents other than the impeller. In this case, the number of seizures increases. Thus, air / oxygen can also be directed to the pipe 3 in a different way than with the impeller 17 shown.

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Any chemicals may preferably be fed to stream a, but may also be added to feed line 16.

The solution according to the invention is also suitable for the treatment of raw water, e.g.

5 for the removal of iron and manganese as well as for the removal of any humus content. Therefore, it is not limited to wastewater treatment alone or in any way. It is equally suitable for foaming and gas treatment / oxidation of all possible liquids and for mixing Kemi-cabbages and homogenizing liquids.

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Claims (7)

Apparatus for treating liquid, especially waste water, comprising a body (1,1a) which consists of a cylindrical part and a conical lower part, a mixing part (I) and a clearing part (6), and which device includes a slurry circulation, a possible foam separation, a feeding tube (16), a lamella separator and a current-causing device (17), characterized in that the mixing part (1) of the processing device is formed by a cylindrical inner cell (2). ) and a conical lower portion (2a) with outlet conduit (7), said mixing portion (I) being arranged in such a way that there remains an annular gap between the body (1,1a) and the mixing portion (I), that a treatment tube ( 3) is arranged inside the inner cell (2), within which the treatment tube (17) is arranged, and the feeding tube (16) is located above the treatment tube (3), that the clearing part (6) of the treatment device is formed by a conical part (6a) surrounding the inner cell (2) and of conical slat portions (6b, 6c, 6d ...), a recess (5) for pure liquid outside the condenser (6a) and possibly an outlet above it for foam and for a layer consisting of liquid solids, and that sludge circulation pipe system (II) is arranged in the treatment device outside the body (1,1a), which pipe system projects from the sludge sampling line (8) in the conical lower part (1,1a) of the treatment device and branching into the sludge outlet tube and into a tube leading to the feed tube (16). 25 Device according to claim 1, characterized in that the upper edges of the inner cell (2) and the treatment tube (3) arranged inside it are at substantially the same level below the liquid surface. Device according to claim 1 or 2, characterized in that the inner cell (2) and the treatment tube (3) are essentially concentric. Device according to any one of claims 1-3, characterized in that the lower edge of the condenser (6a) surrounding the inner cell (2) is below the upper edge of the inner cell (2). 11 ί 'i ~ r r ·:' / v. ' j Device according to any one of claims 1-4, characterized in that the current-causing device (17) is a impeller, in which there is a hollow shaft for sucking air along the shaft of the treatment tube (3). 5 6. Device according to any one of claims 1-5, characterized in that the sludge circulation pipe system (II) includes a device for controlling the relationship between the outlet and circulation currents. 7. Device according to any of claims 1-6, characterized in that there is a separate recess in the outlet conduit (7) for removing heavy precipitation.