ARRANGEMENT FOR PURIFICATION OF WASTE WATER

Abstract: Arrangement comprising a battery (1) in which a number of lengths of pipe (2) are helically wound, layer upon layer and in alternate directions round a central pipe (3) in the middle, and in which the pipe ends (4, 5) seal watertight to two end covers, respectively (6) and (7). The battery (1) is mounted with a vessel (8) round it so that the end covers form a watertight seal to the internal sidewalls of the vessel (8). Over and below the battery (1) the vessel (8) is designed with a chamber or reservoir, respectively (9) and (10). Waste water is fed to one of the reservoirs and discharged as purified waste water from the other reservoir. The flow of water can be continuous or intermittent. The water resistance in the pipes (2) is adjusted in accordance with the pressure head above the arrangement so that all pipe openings (11) are covered with a water table, thus ensuring an even distribution of water to all the pipes (2). Furthermore, the water quantity "Q" flowing through the system is adjusted to the total swept surface area F of the pipes (2) depending on the affinity to water of the impurities. The purification arrangement is rapid and efficient and requires little space. Impurities can be separated out which are lighter than as well an heavier than and of approximately the same specific gravity as water.

Description: Arrangement for purification of waste water The present invention relates to an arrangement for purification of waste water. Clarification/sedimentation systems are known where clarification is obtained by precipitation of suspended sludge. One drawback of such systems is that such clarification takes a long time. Furthermore, substances whose specific gravity is close to that of the water do not precipitate, but will be discharged together with the water through the outlet. It is the purpose of the present invention to describe an arrange¬ ment for the purification of waste water which has none of the draw¬ backs of the known purification systems. This is achieved by embodying the purification arrangement as de¬ scribed in the characterizing part of Claim 1. The result of this is a rapid and efficient removal from the waste water of impurities which are lighter than as well as heavier than water, or of approximately the same specific weight as water. Fur¬ thermore, the arrangement according to the invention takes up consi¬ derably less space than the known plants. By the embodiment described in Claim 2 the arrangement according to the invention takes up as little space as possible. Claim 3 describes a special mode of operation of the arrangement according to the invention. Claim 4 describes another mode of operatiopn of the invention ac- cording to the invention. Claim 5 describes an initial embodiment of a purification ar¬ rangement according to the invention which is well suited for puri¬ fication of the water of impurities which are lighter than water, e.g. oil. Claim 6 describes another embodiment of the arrangement according to the invention, in which the pipe system has water flowing both on the inside and the outside. Claim 7 describes a preferred area of the surface load in an ar¬ rangement according to the invention, when it is used for oil sepa¬ ration. Claim 8 describes a third embodiment of the arrangement according to the invention, which is particularly well suited for purification of waste water when the impurities have approx. the same or higher specific gravity than that of water. The invention is explained in detail below with reference to the drawing in which fig. 1 is a perspective view of a battery for an arrangement ac¬ cording to the invention, fig. 2 is a schematic cross-section through an initial embodiment of an arrangement according to the invention. fig. 3 is a schematic view of a cross-section through another embo¬ diment of an arrangement according to the invention, and fig. 4 is a schematic cross-section through a third embodiment of the invention. As shown in fig. 1 a battery 1 for an arrangement according to the invention consists of a number of lengths of pipe 2 wound helically, layer upon layer in alternate directions, round a central pipe 3 in the middle. The pipe ends 4, 5 and the central pipe 3 are connected watertight to end covers 6 and 7, respectively. As shown in figs. 2-4 the battery 1 is mounted in a vessel 8 so that the end covers 6, 7 seal watertight to the inside of the wall of the vessel 8. As illustrated, the battery 1 is located in the vessel 8 so that the space above the battery 1 contains a reservoir 9 and below the battery another space 10, which as shown in fig. 4 can be embo- died as a reservoir. Water resistance in the pipes 2 is so adjusted to the pressure head above the arrangement so that all the pipe openings 11 are covered with a water table. This ensures an even distribution of the water to all pipes 2. Furthermore, the water volume, Q m 3 /h, flowing through the system is propertioned to the total swept surface area, F m 2 , by the pipes 2 in relation to the affinity to water of the impurities, with a surface load of Q/F = 0.015 m/h the waste water can be strip¬ ped of mechanically and chemically emulgated oil. With a surface load of Q/F = 15.0 m/h the waste water can be stripped of non-emulgated oil. When stripping waste water of emulgated oil it is possible to sepa¬ rate out 90% of the oil, where the known oil separators can separate out only 30-40% at the most. In the embodiment shown in fig. 2 of an arrangement according to the invention the raw waste water enters the reservoir 9 through a pipe 12. The water passes internally through the pipes 2 and at the bottom of reservoir 10 it enters the central pipe 3 in the middle of the vessel from whose top purified waste water is discharged through the outlet pipe 13. The embodiment shown in fig. 2 is well suited as an oil separator. The oil is separated as pearls rising obliquely against the counter- flow of the water and collects at the surface where it can be skim¬ med off or otherwise removed. The embodiment shown in fig. 3 can also be used as an oil separator. The central pipe 3 is carried right to the top of the reservoir 9 which is thus divided into an external annular zone and an internal zone in the pipe 3. The water enters the external zone through a pipe 12. When the ar- rangement is in operation the reservoir 9 is almost full up with water. The water passes internally through the pipes 2 to a bottom reservoir 10, from which it continues through openings 14 in the bottom end cover 7. From this point the water passes up through the battery 1 on the external side of pipes 2 and through openings 15 at the top into the central pipe 3 which has a blind bottom 16. The water is passed down¬ wards towards the bottom 16 and from there out through the pipe 13 which leaves the system so that the pipe outlet 17 comes out a little above the bottom 16. In combination with the central pipe 3 the pipe 13 function as a water trap. In the embodiment shown in fig. 3 there is an primary separation of oil internally in the pipes 2, and this oil collects on the surface of the water in the external annular zone of the reservoir 9, and a secondary separation of oil on the external side of the pipes 2. This secondary oil is transported in through the openings 15 and separated out on the water surface in the internal zone in the pipe 3. In the embodiment according to the invention shown in figs. 2 and 3 the flow of water through the arrangement is continuous. In the embodiment according to the invention shown in fig. 4 the flow of water through the arrangement is intermittent. The arrangement can be designed according to the N-pump principle as described in the applicant's patent application Nr. 3658/89. The upper reservoir 9 is closed with a cover 18 at the top. The re¬ servoir can be put under pressure by means of a blower 19, which is connected to the reservoir by a pipe 20 which opens under the cover 18, and it can be ventilated by means of a venting valve 21, e.g. a magnetic valve, which is connected to the reservoir through a pipe 22, ending under the cover 18. When the system is vented, water will be sent - e.g. from a sludge treatment plant - through a feeder pipe 12, which by means of a T- branch is connected to the initial pipe 24 mounted inside the central pipe 3 and extending a distance down into the reservoir 10. The water is then forced up through the pipes 2 in the battery 1 and taken through openings 25 over an intermediate bottom 26 to the upper pipe opening 27 of the pipe 13. When the system is put under pressure by the closing of the valve 21 and the starting of the blower 19, water will be forced from the re- servoir 9 down through the pipes 2 in the battery 1. This water will loosen sludge deposited on the inside of the pipes 2. The loosened sludge will be transported with the water flow and settle on the bottom of the re¬ servoir 10, where it can be removed through discharge pipe 28.

Claims: P A T E N T C L A I M S 1. Arrangement for purification of waste water, c h a r a c t e r i¬ z e by the fact that the arrangement comprises a number of lengths of pipe (2) wound helically, layer upon layer, round a central pipe (3) in the middle, and where the pipe ends (4, 5) and the central pipe (3) seal watertight to two end covers, respectively (6) and (7), so that in combination they form a battery (1) , which is mounted in an external vessel (8) so that the end covers (6, 7) form a water¬ tight seal against the internal side wall of the vessel (8) and that the vessel (8) above and below the battery (1) includes a chamber or reservoir (9, 10) to which flows waste water and from the other re¬ servoir (10) or (9) is discharged waste water, that the water resist ¬ ance in the pipes (2) is so apportioned to the pressure head above the arrangement that all pipe openings (11) are covered with a water table which ensures an even distribution of water to all the pipes (2), and that the volume, Q m /h, of water flow is apportioned to the total swept area, F m 2 , of the pipes (2) depending on the affinity to water of the impurities. 2. Arrangement for purification of waste water according to claim 1, c h a r a c t -e r i z e d by the pipes 2 being corrugated. 3. Arrangement for purification of waste water according to claim 1, c h a r a c t e r i z e d by the water flow through the arrangement being continuous. 4. Arrangement for purification of waste water according to claim 1, c h a r a c t e r i z e d by the water flow through the arrangement being intermittent. 5. Arrangement for purification of waste water according to claims 1-3, c h a r a c t e r i z e d by the fact that the water enters through the upper end of the pipes (2) , and that the vessel (8) is embodied with an upper reservoir (9) above the pipe cover (6) , which reservoir (9) can be open at the top or closed with a top cover so that the central pipe (3) in combina¬ tion with the bottom end cover (7) form a water trap. 6. Arrangement for purification of waste water according to claims 1-3 and 5, c h a r a c t e r i z e d by the fact that the bottom end cover (7) is embodied with openings (14) and that the central pipe (3) at the top under the upper end cover (6) is embodied with open¬ ings (15) and at the bottom is closed with a cover (16) where a dis¬ charge pipe (13) for purified waste water is carried down the inside of the central pipe (3) so that the pipe outlet (17) is located a little above the bottom (16) of the central pipe. 7. Arrangement for purification of waste water according to claims 1-3, 5 and 6, c h a r a c t e r i z e d by the fact that the surface load QF ranges from 0.015 to 15.0 m/h. 8. Arrangement for purification of waste water according to claims 1 and 4, c h a r a c t e r i z e d by the fact that the vessel (8) is embodied with an upper (9) and a lower reservoir (10) , that inside the central pipe (3) there is an initial pipe (24) to feed waste water to the reservoir (10) and another pipe (13) for discharge of purified waste water from the reservoir (10) to an upper pipe opening (27) of the pipe (13) through openings (25) in the central pipe (3) , and a discharge pipe (28) is attached to the bottom of the reservoir (10) for transport of sludge.

Inventors: FRANDSEN AKSEL SOENDERGAARD, FRANDSEN, AKSEL, SOENDERGAARD
Applicants: FRANDSEN AKSEL S, FRANDSEN, AKSEL, SOENDERGAARD
Application year: 1991
Main classification: B01D17
IPC codes: B01D17, B01D21