APPARATUS FOR TREATING A FLUID WITH A TREATMENT MEDIUM

Abstract: A rotary biological contactor (or R.B.C.) comprises a housing (3) having an inlet (4) and outlet (5) for fluid, a packing of discrete treatment media (2) substantially throughout the housing (3) between the fluid inlet (4) and outlet (5), and external rotational support means (6) adapted to support and rotate the housing (3) whereby on rotation of the housing (3) and passage of fluid from the inlet (4) to the outlet (5), the discrete media (2) contact the fluid for treatment thereof.

Description: APPARATUS FOR TREATING A FLUID WITH A TREATMENT MEDIIM The invention relates to apparatus for treating a fluid with a treatment medium, particularly for treating sewage with treatment media in what is known as a Rotating Biological Contactor (R.B.C.). In prior R.B.C.'s, sewage is passed into a housing which contains plastic discs which are fixedly mounted on a shaft so that the discs rotate when the shaft rotates and pass slcwly through the sewage. Naturally occurring micro-organisms develop on the discs as a film and provide a suitable biological treatment to purify the sewage. Unfortunately, in prior R.B.C.'s the shaft, in order to rotate, is supported on oearmgs and these bearings take a great deal of torque as the slow rotation cakes place. This leads to wear and relatively rapid seizure of tne oearings, which have to be replaced. This means that the treatment is interrupted and the oearings, wnich are expensive nave to oe replaced. It is accordingly an object of the invention to seek to mitigate these disadvantages. According to the invention there is provided apparatus for treating a fluid with a treatment medium, comprising a housing having an inlet and an outlet for fluid, a packing of discrete treatment media substantially throughout the housing between the fluid inlet and outlet, and external rotational support means adapted to support and rotate the housing, whereby on relative rotation between the housing and media and passage of fluid frcm the inlet to the outlet, the discrete treatment media contact the fluid for treatment thereof. The housing may be cylindrical. This provides a relatively sinple construction. The inlet may be in one end wall and the outlet at an opposite end wall of the housing. Again, this provides for a siirple construction and feed to and frcm the apparatus. The outlet may comprise a plurality, preferably eight, of outlet ports leading to a manifold. This provides for a smooth outlet flow. The discrete treatment media may comprise a plurality of plastic spheres. This provides an efficient media having an optiπun treatπent surface area. The plastic spheres may be of different sizes. This provides for close packing of the spheres and enhanced contact. There may be a plurality of spaced apart media retaining means interiorly of the housing and the retaining means may cαηprise a plurality of perforated discs extending diametrically of the housing. This ensures that the interior of the housing is maintained full of evenly distributed media. The discs may ne blank in a central region thereof and perforated in an annular edge region thereof. There may be means adapted to control emission of noxious effluvia from the housing, for exaπple a forced air sup ly means into an inlet manifold or a suction means for maintaining a reduced pressure at the outlet end. The means to rotate the housing may comprise a rotatable wheel or wheels and a drive motor and gearbox. One or both of the wheels may be driven. The whole apparatus may be mounted on a skid. Apparatus emoodying the invention is hereinafter described, by way of exaπple, with reference to tne accαrpanying drawings. Fig. 1 is a longitudinal sectional view through one eπeodiment of apparatus according to the invention for treating sewage with treatment media; Fig. 2 is an end elevational view of the apparatus of Fig.l, taken in the direction of arrow 'A' in that Figure; Fig. 3 is a side elevational view of a second artodiπent of apparatus according to the invention for treating sewage wit treatπent media; Fig. 4 is a longitudinal sectional view through a second eπbodi eπt of apparatus according to the invention; and Fig. 5 and 6 are respectively end elevational views in the direction of the Arrows A', B' of Fig.3. Referring to the drawings in which like parts are referred to b like reference minerals, there is shown in Figs. 1 and 2 a firs eπtoodiment of apparatus 1 for treating a fluid with a treatmen medium, ccπpr sing a housing 3 having an inlet 4 and outlet 5 fo fluid, a packing of discrete treatment media 2 substantiall throughout the housing 3 between the fluid inlet 4 and outlet 5, and external rotational support means 6, adapted to support an rotate the housing 3 whereby on rotation of the housing 3 an passage of fluid frcm the inlet 4 to the outlet 5, the discret media 2 contact the fluid for treatment thereof. The housing 3 is cylindrical and lies with its longitudinal axi *X' substantially horizontal, one end of the cylinder being close by a wall 8 in which there is the inlet 4 for fluid and the othe end being closed by a wall 9 opposite the one end and in whic opposite wall 9 there is the outlet 5 for fluid in the form of plurality of annularly spaced apart outlet ports 5a which lead int a manifold 10. There are eight such outlet ports 5a. The fluid being treated is sewage in the embodiment and in thi case the treatment media 2 corrprises a plurality of plastic sphere 11, of different diameters, which effectively fill the cylinder 3 or dnm. There is interiorly of the cylinder 3 a plurality of media retaining means in the form of spaced perforated discs 12 extending diametrically of the housing 3. Each disc 12 is perforated over an annular region 13 adjacent the periphery, and is blank in the central region 14. The discs 12 assist in retaining the spheres 11 packed evenly in the housing 3. In order to control emission of noxious effluvia from the apparatus 1, there is suction means in the farm of a fan 15 in a pipe 16. The cylinder 2 is mounted on the means 6 comprising external wheels spaced apart along the length thereof as sets, one of which is driven via a suitable drive motor and gearbox 17. The wheel sets 6 themselves are supported on a suitable sub-frame 18. In use, sewage flows into the cylinder 3 through the inlet 4 up to an operational liquid level indicated by the chain dashed line 'Y' in Fig.l. The housing 3 is rotated on the wheels 6 by operation of the motor 17 and this ensures that the liquid and plastic spheres 11 are brought into intimate contact for treatment of the sewage as it flows from the inlet 4, through the perforations 13 in the discs 12 to the outlet ports 5a whence it passes to the manifold 10 and thence to further processing through a pipe 19. The suction air system 15, 16 provides odour control. Referring now to Figs. 3 to 6, there is shown a second ertixDdiment of apparatus 100 which is similar to the first eπixxϋment. Figs, 1, 2 and similar parts are identified by like reference numerals but are not described in order to avoid repetition. In the second embodiment 100, the control means, effective to control emission of noxious effluvia frcm the housing 3 ccπprises a manifold 101 at the inlet end 4 and a manifold 102 at the outlet end 5, there being forced air supply means such as a blower fan 103 for forcing air into the inlet manifold 101 which is therefore at a higher pressure than aπtaient so that noxious effluvia are maintained in the apparatus 100 and do not escape therefrom. Air, once it has passed through the apparatus 100 exits through a pipe 104 at the outle manifold 105, to preferably, peat filters. There is a flexible sea such as a rubber air seal 106 at each end of the housing 3 adjacen the respective manifolds 101, 102 to seek to obviate air leakage Internally of the housing 3 there is a media support grill 10 which maintains the media in the housing. Externally, the housing 3 has spaced circumferential guide mean 108 in the form of guide rails in which wheels 109 are received The wheels 109 are driven wheels, there being a drive motor an gearbox 110 intermediate the wheels 109 substantially centrally o the housing 3. There is a drive connection 111 between the moto and gearbox 110 and the wheels 109 whereby the latter are driven i synchronism. The whole apparatus 3 is mounted on a sub-frame 18 in the form of skid so that the apparatus 100 may be transported. The outlet nozzles 5 in the outlet manifold may be twenty one i nurber, eight of which have bell mouths 5a and thirteen of which 5 are blanked off. This provides for varying through flows in tha more outlets than eight can be opened up. The vtftole apparatus 100 may be received within a retaining wall o a base such as a concrete base laid down for receiving t apparatus. The housing 3 also has two access covers 112 by whic access to the interior can be gained. Each access cover has central hole 113. It will be understood that in both embodiments there is a build of naturally occurring micro-organisms on the surface of t spheres 11 as a biological 'slime' and this provides the necessa biological treatment to treat the sewage, and to purify it, as passes frcm the inlet 4 to the outlet 5. The rotation of t housing 3 ensures an efficient oxygen exchange between the slim and assists in sloughing off surplus slime. The blank 14 parts the discs 121 also act to prevent short-circuiting of the flow sewage through the housing 3 so that the sewage and spheres 11 cαne into thorough mixing contact during treatment. The spheres 11 are of any suitable material such as plastic and are relatively light in weight, having a specific gravity relative to that of the sewage such that the spheres 11 would float, or be semi-submerged therein. The apparatus 1 is, it will be understood, modular.

Claims: CLAIMS 1. Apparatus for treating a fluid with a treatment medium, ccπprising a housing having an inlet and an outlet for fluid, and a packing of discrete treatπent media substantially throughout the housing between the fluid inlet and outlet, characterised by external rotational support means adapted to support and rotate the housing (3) whereby on rotation of the housing (3) and passage of fluid from the inlet (4) to the outlet (5), the discrete treatπent media (11) contact the fluid for treatment thereof. 2. Apparatus according to Claim 1, characterised by the housing (3) being cylindrical. 3. Apparatus according to Claim 2, characterised by the inlet (4) being in one end (8) wall and the outlet (5) at an opposite end wall (9) of the housing (3). 4. Apparatus according to Claim 3, characterised by the outlet (5) coπprising a plurality of outlet ports (5, 5a) leading to a manifold (10, 102). 5. Apparatus according to any precedi g claim, characterised by the discrete treatment media (11) cαηprising a plurality of plastic spheres. 6. Apparatus according to Claim 5, characterised by the plastic spheres (11) being of different sizes. 7. Apparatus according to Claim 6, characterised by a plurality of spaced apart media retaining means (12) interiorly of the housing (3) . 8. Apparatus according to Claim 7, characterised by the retaining means (12) comprising a plurality of perforated discs extending diametrically of the housing (3). 9. Apparatus according to Claim 8, characterised by a central blank part (14) and an annular perforated edge part (13) of each disc (12). 10. Apparatus according to any of Claims 4 to 9, characterised by means (15, 103) adapted to control emission of noxious effluvia from the housing (3). 11. i-pparatus according to Claim 10, characterised by the control means (15, 103) coπprising blower or suction fan means (15 or 103). 12. Apparatus according to any preceding claim, characterised by the means (6,7,109) to rotate the housing (3) ccπprising rotatable wheels (6,7109) and a drive motor and gearbox (17, 110). 13. Apparatus according to Claim 12, characterised by one of the wheels (6) being driven. 14. Apparatus according to any preceding claim, characterised by the means (6, 7, 109) being supported in guide means (108). 15. Apparatus according to any preceding claim, characterised by flexible seal means (106) at the inlet (4) and outlet (5). 16. Apparatus according to any preceding claim, characterised by being mounted on a skid (18) .

Inventors: WALLER CLIFFORD BRIAN, WALLER, CLIFFORD, BRIAN
Applicants: THAMES WATER UTILITIES, THAMES WATER UTILITIES LIMITED
Application year: 1991
Main classification: C02F3
IPC codes: C02F3